fix: address review findings — sendfile EINTR, path traversal check

.gitea/workflows/ci.yaml

@@ -2,7 +2,7 @@ name: CI
 
 on:
   push:
-    branches: [main, dev]
+    branches: [main]
   pull_request:
 
 jobs:
@@ -73,13 +73,6 @@ jobs:
       - name: Build fuzz targets
         run: cmake --build build-fuzz -j$(nproc)
 
-      - name: Smoke fuzz targets
-        run: |
-          for target in build-fuzz/fuzz_*; do
-            [ -x "$target" ] || continue
-            timeout 10s "$target" -runs=100 -max_total_time=5
-          done
-
   coverage:
     runs-on: ubuntu-latest
     container: gitea.tap-tap.win/taptap/fastsync-ci:v9

.gitignore

@@ -5,6 +5,3 @@ __pycache__/
 build-asan
 coverage.info
 build-*/
-build2/
-build3/
-build_docker2/

AGENTS.md

@@ -60,153 +60,15 @@ python3 -m pytest tests/     # integration tests
 
 When running the CI workflow via `tea` (the task execution agent), always set a sufficient timeout (e.g., 600000ms) to allow CI to finish. After CI completes, check the results yourself — do not assume success. Use `gh run watch` or similar to monitor CI status, then inspect logs on failure.
 
-## CI Troubleshooting
-
-### If lint (clang-format) fails
-Run clang-format in the CI Docker image to match the exact CI version:
-```bash
-docker run --rm -v "$PWD:/workspace" -w /workspace gitea.tap-tap.win/taptap/fastsync-ci:v9 \
-  sh -c 'find src/ tests/ -name "*.c" -o -name "*.h" | xargs clang-format -i'
-```
-
-### If cppcheck fails
-Fix reported issues locally, then verify with:
-```bash
-docker run --rm -v "$PWD:/workspace" -w /workspace gitea.tap-tap.win/taptap/fastsync-ci:v9 \
-  sh -c 'cppcheck --enable=warning,style,performance,portability --suppress=missingIncludeSystem --error-exitcode=1 --inline-suppr src/ tests/'
-```
-
-### If integration tests fail
-Run locally before pushing:
-```bash
-python3 -m pytest tests/ -v --tb=short
-```
-
 ## Branch Strategy
 
-Two main branches: `dev` (integration) and `main` (stable releases).
+Never push directly to `main`. All changes must be developed on a feature branch and merged via a pull request. Always create a new branch before making changes:
-
-### Rules
-- **All PRs target `dev`** — never target `main` directly
-- **`dev` is the default branch** in Gitea repo settings
-- **`main` is protected** — only merged from `dev` via PR with 2 approvals + full CI pass
-- **Feature/bug branches** branch from `dev`, PR back to `dev`
-- **`dev` → `main` merges** happen on-demand or weekly, requiring full CI + review
-
 ```bash
-# Start a new feature
+git checkout -b <feature-branch-name>
-git checkout dev && git pull
-git checkout -b feat/my-feature
-# ... work, commit, push
-git push -u origin feat/my-feature
-# Create PR targeting dev
 ```
-
+After committing changes, push the branch and create a PR:
-### Creating the `dev` branch (one-time setup)
 ```bash
-git checkout main && git pull
+git push -u origin <feature-branch-name>
-git checkout -b dev
+gh pr create --fill
-git push origin dev
-# Then in Gitea: Settings → Repository → Default Branch → dev
 ```
-
+Wait for CI to pass on the PR before merging.
-### Branch protection (Gitea repo settings)
-**For `dev`:**
-- ✅ Require PR for merging
-- ✅ Require 1 approval
-- ✅ Require status checks (all CI jobs must pass)
-- ✅ Delete branch after merge
-
-**For `main`:**
-- ✅ Require PR from `dev` only
-- ✅ Require CI
-- ✅ Require 2 approvals
-- ✅ No direct pushes
-
-## Automated Agent Workflows
-
-All agents run locally via the opencode CLI. There is no CI-based agent automation — agents are invoked on-demand by the developer or by this assistant.
-
-### One-command batch workflow
-
-For fixing a set of issues and creating one integration PR:
-
-```bash
-# 1. Run each subagent on its category
-opencode run --agent security-auditor "Fix all open security issues"
-opencode run --agent debugger "Fix all open bugs"
-opencode run --agent test-writer "Add missing test coverage"
-
-# 2. The assistant handles: merging branches, fixing CI failures,
-#    pushing, creating the integration PR, waiting for CI, iterating.
-#    The developer only reviews the final PR.
-```
-
-### Issue triage loop
-When you want to fix a batch of issues autonomously:
-
-1. Tell the assistant: *"Fix all open issues and create one big PR"*
-2. The assistant delegates to subagents in parallel
-3. Merges their branches, handles CI failures iteratively
-4. Pushes and opens the final PR
-5. You review the PR once CI passes — no intermediate check-ins
-
-### Scheduling
-For periodic maintenance (security audits, code quality scans), run:
-
-```bash
-opencode run --agent security-auditor "Audit the codebase for vulnerabilities"
-opencode run --agent code-quality-guardian "Scan for code quality issues"
-```
-
-This can be cron'd locally if desired (e.g., `crontab -e` with `opencode run`).
-
-## Is opencode a good option?
-
-**Yes, for FastSync's needs.** The hybrid model works well:
-- opencode's 17 specialized agents handle deep code analysis, fixes, tests, and reviews
-- The assistant orchestrates subagents, merges branches, and iterates on CI
-- You only review the final output
-
-The key limitation: opencode is session-based, not a persistent daemon. But for the "fix all issues, one PR" workflow, this is fine — the assistant runs the full pipeline in one shot. Persistent webhook-driven automation isn't available for Gitea, but the one-shot batch approach is simpler and gives you full control over what gets merged.
-
-### Recommendations for this project
-- **Do** use the batch pattern: delegate to subagents, let the assistant merge + iterate CI, review once
-- **Don't** try to run opencode in Gitea Actions — the CI container doesn't have your LLM keys or the interactive context agents need
-- **If** you want fully hands-off periodic scans, set up a local cron job or systemd timer that runs `opencode run` and posts results to Gitea via API
-
-## Gitea API & tea CLI
-
-### Check CI status via API
-```bash
-TOKEN="<token>"
-curl -s -H "Authorization: token $TOKEN" \
-  "https://gitea.tap-tap.win/api/v1/repos/TapTap/FastSync/actions/runs?limit=5" \
-  | python3 -c "
-import json,sys; d=json.load(sys.stdin)
-for r in d.get('workflow_runs',[]):
-    path = r.get('path','')
-    prn = path.split('@')[1].replace('refs/pull/','').replace('/head','') if '@' in path else ''
-    print(f'PR #{prn}: sha={r[\"head_sha\"][:8]} {r[\"status\"]} {r.get(\"conclusion\",\"\")}')
-"
-```
-
-### Post review comments
-```bash
-curl -s -X POST -H "Authorization: token $TOKEN" -H "Content-Type: application/json" \
-  -d '{"body":"MARKDOWN_REVIEW_BODY"}' \
-  "https://gitea.tap-tap.win/api/v1/repos/TapTap/FastSync/issues/<PR_NUMBER>/comments"
-```
-
-### Use tea for PR operations
-```bash
-tea pr list --repo TapTap/FastSync
-tea pr close <number> --repo TapTap/FastSync
-```
-
-## Common pitfalls
-
-- **`__thread` on shared SSL context**: io_ssl must NOT be thread-local — worker threads inherit the SSL context from the main thread. Use regular `static SSL* io_ssl`.
-- **SSL WANT_READ/WANT_WRITE retry**: Always retry on `SSL_ERROR_WANT_READ` and `SSL_ERROR_WANT_WRITE` in `send_n_data`/`receive_n_data`. Removing these breaks TLS multithreaded transfers.
-- **clang-format version**: The CI image uses clang-format 18. Always format inside the CI Docker container for exact match.
-- **Merge order matters**: Merge the most comprehensive branch first, then smaller ones, to minimize conflicts when creating a combined branch.

README.md

@@ -5,26 +5,17 @@ A high-performance file synchronization system with SSH and TCP transport, TLS e
 ## Technical Overview
 
 1. **Dual transport**: custom TCP client-server or SSH subprocess (rsync-style `user@host:/path`)
-2. **TLS encryption**: OpenSSL-based TLS 1.2+ for encrypted TCP connections with optional CA verification
+2. **TLS encryption**: OpenSSL-based TLS 1.2+ for encrypted TCP connections
 3. **Chunked file transfer**: files grouped into configurable-size chunks (default ~10 MB)
 4. **Streaming zstd compression** (levels 1–22) using `ZSTD_compressStream2`
 5. **Multithreading**: producer-consumer pipeline with thread-safe queues (scanner → loader → sender)
 6. **Incremental sync**: skip files unchanged since last transfer (compares size + mtime)
-7. **Batch incremental**: send incremental checks in batched groups for reduced round-trips
+7. **Metadata preservation**: `mode`, `uid`, `gid`, `mtime` restored on disk when enabled
-8. **Metadata preservation**: `mode`, `uid`, `gid`, `mtime` restored on disk when enabled
+8. **`sendfile()` zero-copy** on TCP (~2× faster on loopback)
-9. **`sendfile()` zero-copy** on TCP (~2× faster on loopback)
+9. **SSH ControlMaster** for connection reuse across repeated invocations
-10. **SSH ControlMaster** for connection reuse across repeated invocations
+10. **Bandwidth limiting**: token-bucket throttling (`--bwlimit`)
-11. **Bandwidth limiting**: token-bucket throttling (`--bwlimit`)
+11. **`--delete`**: receiver removes files not present in sender manifest
-12. **`--delete`**: receiver removes files not present in sender manifest
+12. **`--exclude` / `--include`**: glob-pattern filename filtering
-13. **`--exclude` / `--include`**: glob-pattern filename filtering
-14. **Path traversal protection**: `..` sequences in file paths are rejected automatically
-15. **Connection limits**: server enforces maximum concurrent connections (default 100)
-16. **Keep-alive**: periodic `STATUS_KEEPALIVE` messages detect stalled connections
-17. **Abort handling**: `SIGINT` sends `STATUS_ABORT` for clean server-side teardown
-18. **Atomic writes**: received files are written to a temporary name then atomically renamed
-19. **Backup mode**: `--backup` preserves overwritten files with optional `--backup-dir`
-20. **Log file**: `--log-file` redirects log output to a file instead of stderr
-21. **Transfer statistics**: `--stats` prints summary of transferred bytes, files, and timing
 
 ## System Architecture
 
@@ -34,33 +25,20 @@ A high-performance file synchronization system with SSH and TCP transport, TLS e
 - Streaming zstd compression with configurable level
 - Chunk serialization (compact binary format) or per-file transfer
 - Incremental transfer: sends file metadata to server, skips unchanged files
-- Batch incremental: groups incremental checks to minimize round-trips
 - Manifests all sent paths when `--delete` is active
 - Sends via TCP `sendfile()` or SSH pipe
 - Optional progress display with throughput
 - Bandwidth limiting via token-bucket algorithm
-- Configurable I/O and connection timeouts (`--timeout`, `--contimeout`)
-- Quiet mode (`-q`/`--quiet`) suppresses all non-error output
-- Backup overwritten files (`--backup`) with optional directory (`--backup-dir`)
-- Transfer statistics summary (`--stats`)
-- Maximum directory depth control (`--max-depth`)
-- Log file output (`--log-file`)
-- Configurable multithreaded queue size (`--queue-size`)
-- Exclude patterns from file (`--exclude-from`)
 
 ### Server
 - TCP mode: listens on configurable port (default 8080); SSH mode: runs via `--stdio`
-- TLS mode: wraps TCP connections with OpenSSL with optional CA verification
+- TLS mode: wraps TCP connections with OpenSSL
 - Receives and reassembles files
 - Decompresses (streaming zstd), deserializes, restores metadata
 - Handles incremental checks: compares size + mtime against destination files
-- Handles batch incremental checks for reduced round-trips
 - Processes `STATUS_MANIFEST` for `--delete`: walks destination tree, removes extras
-- Per-connection concurrency via `fork()` with configurable connection limit (default 100)
+- Per-connection concurrency via `fork()`
 - Thread pool for parallel processing
-- Atomic writes: files written to `.tmp` path then atomically renamed on success
-- Abort handling: cleanly shuts down on `STATUS_ABORT` from client
-- Path traversal protection: rejects file paths containing `..`
 
 ## Protocol Details
 
@@ -73,12 +51,7 @@ A high-performance file synchronization system with SSH and TCP transport, TLS e
 | `STATUS_NEXT` | Ready for next file (per-file mode) |
 | `STATUS_CHUNK` | Following data is a serialized chunk |
 | `STATUS_MANIFEST` | Following data is a file manifest (for `--delete`) |
-| `STATUS_CHECK` | Incremental check: client sends file path + size + mtime and, when negotiated, checksum; server responds with OK (skip) or NEXT (send) |
+| `STATUS_CHECK` | Incremental check: client sends file path + size + mtime, server responds with OK (skip) or NEXT (send) |
-| `STATUS_CHECK_BATCH` | Batch incremental check: multiple file checks sent in one message |
-| `STATUS_KEEPALIVE` | Keep-alive heartbeat to detect stalled connections |
-| `STATUS_ABORT` | Abort signal: client interrupts, server cleans up and exits |
-| `STATUS_DELTA_SIGNATURE` | Delta sync: following data is a file signature (rsync-style rolling hash) |
-| `STATUS_DELTA_DATA` | Delta sync: following data is a delta patch for a file |
 
 ### Wire Format — Metadata
 
@@ -86,18 +59,12 @@ When `use_metadata` is enabled (`-M`), each file entry carries a 4-byte `present
 
 ### Transfer Flow
 ```
-Config → (STATUS_NEXT | STATUS_CHUNK | STATUS_CHECK | STATUS_CHECK_BATCH)* → [STATUS_MANIFEST] → STATUS_FINISHED → STATUS_OK
+Config → (STATUS_NEXT | STATUS_CHUNK | STATUS_CHECK)* → [STATUS_MANIFEST] → STATUS_FINISHED → STATUS_OK
 ```
 
-Keep-alive (`STATUS_KEEPALIVE`) may be sent at any point during the transfer. The receiver resets its inactivity timer on receipt. If no data arrives within the receive timeout, the connection is aborted.
-
-Abort (`STATUS_ABORT`) may be sent at any point. On receipt the server cleans up temporary files and exits the child process.
-
 ### Protocol Version
 
-`2.2.0` — server and client must match. This version adds a 64-bit XXH64 checksum to checksum-enabled `STATUS_CHECK` messages and validates the negotiated compression choice (`zstd` or `none`). Older clients and servers must not be mixed with this version; mismatch results in `STATUS_ERROR`.
+`1.1.0` — server and client must match. Mismatch results in `STATUS_ERROR`.
-
-Config negotiation is sender-driven: the client serializes transfer options and the server applies them while receiving and writing files. `--checksum` compares size and content checksum instead of timestamps. `--compress-choice zstd` enables zstd; `none` disables it. Unsupported choices are rejected during config exchange.
 
 ## Command-Line Arguments
 
@@ -116,26 +83,15 @@ Config negotiation is sender-driven: the client serializes transfer options and
 | `-n, --dry-run` | Scan and print what would be transferred |
 | `-p <port>` | SSH port (default: 22) |
 | `-v, --verbose` | Enable debug logging |
-| `-q, --quiet` | Suppress all non-error output |
-| `--silent` | Alias for `--quiet` |
 | `--progress` | Show real-time transfer speed |
 | `--delete` | Delete files on receiver not present in source |
 | `--exclude <pattern>` | Exclude files matching glob pattern (repeatable) |
-| `--exclude-from <file>` | Read exclude patterns from a file (one per line) |
 | `--include <pattern>` | Only transfer files matching glob pattern (repeatable, whitelist) |
 | `--max-size <n>` | Skip files larger than n bytes |
 | `--min-size <n>` | Skip files smaller than n bytes |
 | `--incremental` | Skip files unchanged since last transfer (size + mtime). Auto-enables `--preserve`. Incompatible with `-s`. |
 | `--bwlimit <KB/s>` | Bandwidth limit in kilobytes per second |
 | `--chunk-size <n>` | Chunk size in bytes (default: 10485760) |
-| `--timeout <sec>` | I/O timeout in seconds (default: 30) |
-| `--contimeout <sec>` | Connection timeout in seconds (default: 10) |
-| `--backup` | Backup existing destination files before overwriting |
-| `--backup-dir <dir>` | Target directory for backups (requires `--backup`) |
-| `--stats` | Print transfer statistics at end (bytes, files, timing) |
-| `--max-depth <n>` | Maximum directory depth to recurse (0 = unlimited, default: 0) |
-| `--log-file <path>` | Write log messages to file instead of stderr |
-| `--queue-size <n>` | Queue capacity for multithreaded mode (default: 100) |
 | `--source-dir <path>` | Source directory (overrides `FASTSYNC_SOURCE_DIR`) |
 | `--dest-dir <path>` | Server destination directory (overrides `FASTSYNC_DEST_DIR`) |
 | `--save-to-disk` | Write received files to disk |
@@ -166,12 +122,6 @@ Config negotiation is sender-driven: the client serializes transfer options and
 | `FASTSYNC_SOURCE_DIR` | — | Source directory fallback |
 | `FASTSYNC_DEST_DIR` | — | Destination directory fallback |
 | `FASTSYNC_SAVE_TO_DISK` | `false` | Disk persistence fallback |
-| `FASTSYNC_SSH_PORT` | `22` | Default SSH port |
-| `FASTSYNC_SERVER_HOST` | `127.0.0.1` | Default server host |
-| `FASTSYNC_SERVER_PORT` | `8080` | Default server port |
-| `FASTSYNC_TLS_CERT` | — | Default TLS certificate path |
-| `FASTSYNC_TLS_KEY` | — | Default TLS private key path |
-| `FASTSYNC_TLS_CA` | — | Default TLS CA certificate path |
 
 ## Implementation Details
 
@@ -179,44 +129,21 @@ Config negotiation is sender-driven: the client serializes transfer options and
 1. **Chunk** — collection of files (~10 MB total by default)
 2. **File** — path, content (`Data`), optional `FileMetadata` pointer
 3. **FileMetadata** — `mode`, `uid`, `gid`, `mtime_sec`, `mtime_nsec`
-4. **Config** — runtime parameters (transported over wire, TLS settings excluded). Includes `timeout`, `contimeout`, `quiet`, `backup`, `backup_dir`, `stats`, `max_depth`, `log_file`, `queue_size`.
+4. **Config** — runtime parameters (transported over wire, TLS settings excluded)
 5. **Queue** — thread-safe bounded queue with condition variables
-6. **DirectoryScanner** — recursive BFS traversal with exclude and include pattern support, max-depth enforcement
+6. **DirectoryScanner** — recursive BFS traversal with exclude and include pattern support
 
 ### Key Algorithms
-1. **File scanning** — BFS directory traversal; entries matched against exclude and include patterns, max-depth enforced
+1. **File scanning** — BFS directory traversal; entries matched against exclude and include patterns
 2. **Chunking** — files accumulated until `chunk_size` threshold, then flushed
 3. **Compression** — streaming zstd via `ZSTD_compressStream2` / `ZSTD_decompressStream`
-4. **Network protocol** — status-code-driven exchange with metadata packing, keep-alive, and abort support
+4. **Network protocol** — status-code-driven exchange with metadata packing
-5. **Incremental check** — client sends `STATUS_CHECK` + path + size + mtime and, with `--checksum`, XXH64 content checksum; server compares against destination. Can be batched via `STATUS_CHECK_BATCH` for reduced round-trips.
+5. **Incremental check** — client sends `STATUS_CHECK` + path + size + mtime; server compares against destination
 6. **Bandwidth limiting** — token-bucket algorithm with `nanosleep` throttling on 64 KB write chunks
 7. **Metadata restoration** — `chmod()`, `chown()`, `utimensat()` on the receiving side
 8. **`--delete`** — sender tracks all sent paths; receiver walks destination tree and removes unlisted files/directories
 9. **SSH transport** — `socketpair()` + `fork()` + `execvp("ssh", ...)` with `ControlMaster` and port support
 10. **TLS transport** — OpenSSL `SSL_CTX` with TLS 1.2 minimum, optional CA verification, transparent `SSL_read`/`SSL_write` via `io_set_ssl()`
-11. **Path traversal protection** — `has_path_traversal()` rejects any file path containing `..` components, preventing directory escape attacks
-12. **Connection limiting** — server tracks active connections and rejects new ones beyond `max_connections` (default 100)
-13. **Keep-alive** — idle connections receive periodic `STATUS_KEEPALIVE` to detect half-open TCP connections
-14. **Abort handling** — `SIGINT` sets an abort flag; the next protocol operation sends `STATUS_ABORT` for clean server cleanup
-15. **Atomic writes** — files are written to a `.tmp` suffix then atomically renamed via `rename()`, preventing partial files
-16. **Backup** — before overwriting, existing files are moved to `--backup-dir` (or same directory with `~` suffix) preserving the original
-
-## Security Features
-
-### Path Traversal Protection
-All received file paths are validated by `has_path_traversal()` before any disk operation. Any path containing `..` components is rejected with `STATUS_ERROR`, preventing directory escape attacks.
-
-### TLS Certificate Verification
-When `--ca` is provided, the server performs mutual TLS verification (`SSL_VERIFY_PEER` with depth 4). Without `--ca`, TLS is still encrypted but peer certificates are not verified.
-
-### Connection Limits
-The server enforces a maximum of 100 concurrent connections (configurable via `max_connections` in `Server`). When the limit is reached, new connections are immediately rejected and closed.
-
-### Abort Handling
-If the client receives `SIGINT` (Ctrl+C) during a transfer, it sends `STATUS_ABORT` to the server. The server then cleans up temporary files and exits the child process, preventing incomplete files from remaining on disk.
-
-### Atomic Writes
-Received files are written to a temporary path (suffixed with `.tmp`) and then atomically renamed to the final filename via `rename()`. This prevents partial or corrupted files from appearing at the destination if the transfer is interrupted.
 
 ## Build Requirements
 
@@ -296,21 +223,6 @@ Place the `fastsync-server` binary in the remote `$PATH`. The client runs `ssh u
 # Bandwidth limit to 1 MB/s
 ./build/client --bwlimit 1024 /src user@host:/dst
 
-# With timeouts, quiet mode, and stats
-./build/client --timeout 60 --contimeout 15 --quiet --stats /src user@host:/dst
-
-# Backup overwritten files to a directory
-./build/client --backup --backup-dir /backups /src user@host:/dst
-
-# Exclude patterns from file, limit depth
-./build/client --exclude-from ignore.txt --max-depth 3 /src user@host:/dst
-
-# Custom queue size for multithreading
-./build/client -m --queue-size 200 /src user@host:/dst
-
-# Log to file
-./build/client --log-file /tmp/fastsync.log /src user@host:/dst
-
 # All features
 ./build/client -a --progress --chunk-size 5242880 --exclude "*.log" --delete /src /dst
 ```
@@ -318,9 +230,7 @@ Place the `fastsync-server` binary in the remote `$PATH`. The client runs `ssh u
 ## Testing
 
 ```bash
-# Unit tests (18 suites — array_list, chunk, compression, config, data, delta, file, glob,
+# Unit tests (7 suites)
-#                      metadata, property, protocol, queue, robustness, scanner,
-#                      shared_utils, stress, transport_tcp, transport_ssh, transport_tls)
 ./build/tests
 
 # Integration + benchmark suite
@@ -334,15 +244,12 @@ The benchmark prints throughput metrics, best configuration, and speedup vs rsyn
 1. Chunk size (~10 MB default) balances memory and transfer efficiency
 2. Compression level trades CPU for bandwidth
 3. `sendfile()` bypasses userspace — ~2× faster on localhost for large files
-4. Multithreading scales with core count; `--queue-size` controls pipeline buffering
+4. Multithreading scales with core count
 5. Metadata transfer adds negligible overhead (~24 bytes per file when enabled)
 6. SSH socketpair buffer set to 1 MB for improved pipe throughput
 7. SSH ControlMaster reuses connections across repeated invocations
 8. Incremental sync eliminates redundant transfers entirely
-9. Batch incremental reduces round-trips by grouping multiple checks into one message
+9. Bandwidth limiting uses token-bucket with nanosleep for accurate throttling
-10. Bandwidth limiting uses token-bucket with nanosleep for accurate throttling
-11. Atomic writes add a single `rename()` per file — negligible overhead
-12. Path traversal check is O(n) in path length with negligible cost
 
 ## Benchmark Results
 

RSYNC_COMPAT.md

@@ -1,274 +0,0 @@
-# Rsync Feature Compatibility
-
-This document maps rsync's full feature set to FastSync's current implementation status.
-
-## Summary
-
-| Status | Count | Description |
-|--------|-------|-------------|
-| ✅ Implemented | 39 | Feature works end-to-end |
-| 🔀 Alt Arg | 5 | Functionality exists but under different flag/semantics |
-| ⚠️ Partial | 30 | Flag parsed/stored but behavior incomplete |
-| ❌ Not Implemented | 62 | Flag not recognized or no behavior |
-| **Total** | **136** | |
-
----
-
-## 1. General Options
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-a`, `--archive` | Archive mode is -rlptgoD | 🔀 Alt Arg | Maps to -c -m -M (compression + multithread + metadata) |
-| `-v`, `--verbose` | Increase verbosity | ✅ Implemented | Sets `log_level=DEBUG` |
-| `-q`, `--quiet` | Suppress non-error messages | ✅ Implemented | `quiet` config field |
-| `-h`, `--help` | Show help | ✅ Implemented | Prints usage and exits |
-| `-V`, `--version` | Print version | ❌ Not Implemented | |
-| `--info=FLAGS` | Fine-grained info verbosity | ⚠️ Partial | `info_level` stored, not wired |
-| `--debug=FLAGS` | Fine-grained debug verbosity | ⚠️ Partial | `debug_level` stored, not wired |
-| `--stderr=MODE` | Change stderr output mode | ❌ Not Implemented | |
-| `--no-motd` | Suppress daemon MOTD | ❌ Not Implemented | |
-| `--exclude=PATTERN` | Exclude files matching pattern | ✅ Implemented | Glob matching in scanner |
-| `--include=PATTERN` | Include files matching pattern | ✅ Implemented | Glob matching in scanner |
-| `-C`, `--cvs-exclude` | Auto-ignore CVS files | ⚠️ Partial | `cvs_exclude` stored, not wired |
-
-## 2. Modifying Output
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--stats` | Give transfer stats | ✅ Implemented | Prints file/byte counts |
-| `-h`, `--human-readable` | Human-readable numbers | ⚠️ Partial | `human_readable` stored, not wired |
-| `-i`, `--itemize-changes` | Per-file change summary | ⚠️ Partial | `itemize_changes` stored, not wired |
-| `--progress` | Show progress | ✅ Implemented | Progress callback in sender |
-| `-P` | Same as --partial --progress | ❌ Not Implemented | |
-| `--out-format=FORMAT` | Custom output format | ⚠️ Partial | `out_format` stored, not wired |
-| `--log-file=FILE` | Log to file | ✅ Implemented | `log_file` config field |
-| `--log-file-format=FMT` | Log format | ❌ Not Implemented | |
-| `--8-bit-output` | Leave high-bit chars unescaped | ❌ Not Implemented | |
-| `--list-only` | List files instead of copying | ⚠️ Partial | `list_only` stored, not wired |
-
-## 3. File Selection
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--exclude-from=FILE` | Read exclude patterns from file | ✅ Implemented | Reads patterns from file |
-| `--include-from=FILE` | Read include patterns from file | ✅ Implemented | Reads patterns from file |
-| `--filter=RULE` | Add file-filtering rule | ⚠️ Partial | `filters` ArrayList stored, not wired |
-| `--files-from=FILE` | Read source file list from file | ⚠️ Partial | `files_from` stored, not wired |
-| `-0`, `--from0` | Delimit *-from files with NULs | ❌ Not Implemented | |
-| `--max-size=SIZE` | Skip files larger than SIZE | ✅ Implemented | `max_size` in scanner |
-| `--min-size=SIZE` | Skip files smaller than SIZE | ✅ Implemented | `min_size` in scanner |
-| `-I`, `--ignore-times` | Don't skip files matching size+time | ❌ Not Implemented | |
-| `--size-only` | Skip based on size only | ❌ Not Implemented | |
-| `-@`, `--modify-window=NUM` | Mod-time comparison accuracy | ❌ Not Implemented | |
-| `--existing` | Skip creating new files on receiver | ❌ Not Implemented | |
-| `--ignore-existing` | Skip updating existing files | ❌ Not Implemented | |
-| `--remove-source-files` | Sender removes synced files | ❌ Not Implemented | |
-
-## 4. Directory Options
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-r`, `--recursive` | Recurse into directories | ✅ Implemented | Default behavior |
-| `-R`, `--relative` | Use relative path names | ⚠️ Partial | `relative` stored, not wired |
-| `--no-implied-dirs` | Don't send implied dirs with -R | ❌ Not Implemented | |
-| `-d`, `--dirs` | Transfer dirs without recursing | ❌ Not Implemented | |
-| `--mkpath` | Create missing path components | ❌ Not Implemented | |
-
-## 5. Transfer Modifications
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-u`, `--update` | Skip files newer on receiver | ⚠️ Partial | `update` stored, not wired |
-| `--inplace` | Update files in-place | ✅ Implemented | Direct write mode |
-| `--append` | Append data to shorter files | ⚠️ Partial | `append` stored, not wired |
-| `--append-verify` | Append with old-data checksum | ⚠️ Partial | `append_verify` stored, not wired |
-| `-W`, `--whole-file` | Copy whole file (no delta) | ❌ Not Implemented | |
-| `--block-size=SIZE` | Force checksum block-size | ⚠️ Partial | Parsed as `--delta-block`; controls delta transfer block size |
-
-## 6. Destination Handling
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-n`, `--dry-run` | Trial run with no changes | ✅ Implemented | `dry_run` config field |
-| `-b`, `--backup` | Make backups of overwritten files | ✅ Implemented | Backup before overwrite |
-| `--backup-dir=DIR` | Backup directory hierarchy | ✅ Implemented | `backup_dir` config field |
-| `--suffix=SUFFIX` | Backup suffix (default ~) | ✅ Implemented | `suffix` config field |
-| `--delay-updates` | Put updated files in place at end | ❌ Not Implemented | |
-
-## 7. Deletion
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--delete` | Delete extraneous files from dest | ✅ Implemented | `use_delete` config field |
-| `--delete-before` | Delete before transfer | ⚠️ Partial | `delete_before` stored, not wired |
-| `--delete-during` | Delete during transfer | ❌ Not Implemented | |
-| `--delete-delay` | Find deletions during, delete after | ❌ Not Implemented | |
-| `--delete-after` | Delete after transfer | ⚠️ Partial | `delete_after` stored, not wired |
-| `--delete-excluded` | Also delete excluded files | ⚠️ Partial | `delete_excluded` stored, not wired |
-| `--max-delete=NUM` | Max files to delete | ⚠️ Partial | `max_delete` stored, not wired |
-| `--ignore-errors` | Delete even with I/O errors | ❌ Not Implemented | |
-| `--force` | Force deletion of non-empty dirs | ❌ Not Implemented | |
-| `--prune-empty-dirs` | Prune empty dir chains | ⚠️ Partial | `prune_empty_dirs` stored, not wired |
-
-## 8. Metadata Preservation
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-M`, `--preserve` | Preserve file metadata | ✅ Implemented | Mode, uid, gid, mtime |
-| `-p`, `--perms` | Preserve permissions | 🔀 Alt Arg | `-p` means SSH port; permissions preserved via `-M`/`--preserve` |
-| `-o`, `--owner` | Preserve owner | ✅ Implemented | Part of -M |
-| `-g`, `--group` | Preserve group | ✅ Implemented | Part of -M |
-| `-t`, `--times` | Preserve modification times | ✅ Implemented | Part of -M |
-| `-E`, `--executability` | Preserve executability | ❌ Not Implemented | |
-| `--chmod=CHMOD` | Affect file permissions | ❌ Not Implemented | |
-| `-A`, `--acls` | Preserve ACLs | ⚠️ Partial | `preserve_acls` stored, not wired |
-| `-X`, `--xattrs` | Preserve extended attributes | ⚠️ Partial | `preserve_xattrs` stored, not wired |
-| `-H`, `--hard-links` | Preserve hard links | ⚠️ Partial | `preserve_hard_links` stored, not wired |
-| `-D` | Same as --devices --specials | 🔀 Alt Arg | Maps to --devices only (no --specials) |
-| `--devices` | Preserve device files | ⚠️ Partial | `preserve_devices` stored, not wired |
-| `--specials` | Preserve special files | ❌ Not Implemented | |
-| `--copy-devices` | Copy device contents as file | ❌ Not Implemented | |
-| `--write-devices` | Write to devices as files | ❌ Not Implemented | |
-| `-U`, `--atimes` | Preserve access times | ❌ Not Implemented | |
-| `-N`, `--crtimes` | Preserve create times | ❌ Not Implemented | |
-| `-O`, `--omit-dir-times` | Omit dirs from --times | ❌ Not Implemented | |
-| `-J`, `--omit-link-times` | Omit symlinks from --times | ❌ Not Implemented | |
-| `--super` | Receiver attempts super-user activities | ❌ Not Implemented | |
-| `--fake-super` | Store/recover privileged attrs via xattrs | ❌ Not Implemented | |
-
-## 9. Symlink Handling
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-l`, `--links` | Copy symlinks as symlinks | ⚠️ Partial | Scanner includes symlinks; target path not transmitted |
-| `-L`, `--copy-links` | Transform symlink to referent | ✅ Implemented | `copy_links` config field |
-| `--copy-unsafe-links` | Transform unsafe symlinks | ✅ Implemented | `copy_unsafe_links` config field |
-| `--safe-links` | Ignore symlinks outside tree | ✅ Implemented | `safe_links` config field |
-| `--munge-links` | Munge symlinks for safety | ❌ Not Implemented | |
-| `-k`, `--copy-dirlinks` | Transform symlink to dir | ❌ Not Implemented | |
-| `-K`, `--keep-dirlinks` | Treat symlinked dir as dir | ❌ Not Implemented | |
-
-## 10. Sparse & Device
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-S`, `--sparse` | Sparse block handling | ✅ Implemented | `preserve_sparse` config field |
-| `--preallocate` | Allocate dest files before writing | ❌ Not Implemented | |
-
-## 11. Checksum & Comparison
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-c`, `--checksum` | Skip based on checksum | 🔀 Alt Arg | `-c` means compression; `--checksum` stored and forwarded to scanner |
-| `--checksum-choice=STR` | Choose checksum algorithm | ❌ Not Implemented | xxHash used internally |
-| `--compare-dest=DIR` | Compare dest files relative to DIR | ⚠️ Partial | `compare_dest` stored, not wired |
-| `--copy-dest=DIR` | Include copies of unchanged files | ⚠️ Partial | `copy_dest` stored, not wired |
-| `--link-dest=DIR` | Hardlink to files when unchanged | ⚠️ Partial | `link_dest` stored, not wired |
-| `--fuzzy`, `--no-fuzzy` | Find similar file for basis | ❌ Not Implemented | |
-
-## 12. Compression
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-z`, `--compress` | Compress file data | 🔀 Alt Arg | Always uses zstd (rsync supports multiple algorithms) |
-| `--compress-choice=STR` | Choose compression algorithm | ⚠️ Partial | `compress_choice` stored, always zstd |
-| `--compress-level=NUM` | Set compression level | ✅ Implemented | 1-22, default 5 |
-| `--compress-threads=NUM` | Set compression threads | ❌ Not Implemented | |
-| `--skip-compress=LIST` | Skip compress for suffixes | ❌ Not Implemented | Internal skip for hardcoded types; not user-configurable |
-
-## 13. Connectivity
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `-e`, `--rsh=COMMAND` | Remote shell to use | ✅ Implemented | SSH transport support |
-| `--rsync-path=PROGRAM` | rsync binary on remote | ✅ Implemented | `rsync_path` config field |
-| `--port=PORT` | Alternate daemon port | ✅ Implemented | `server_port` config field |
-| `--sockopts=OPTIONS` | Custom TCP options | ❌ Not Implemented | |
-| `--blocking-io` | Use blocking I/O for remote shell | ❌ Not Implemented | |
-| `--outbuf=N\|L\|B` | Set output buffering | ❌ Not Implemented | |
-| `--address=ADDRESS` | Bind address for outgoing socket | ✅ Implemented | `address` config field |
-| `-4`, `--ipv4` | Prefer IPv4 | ✅ Implemented | `ipv4` config field |
-| `-6`, `--ipv6` | Prefer IPv6 | ✅ Implemented | `ipv6` config field |
-
-## 14. Daemon Mode
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--daemon` | Run as rsync daemon | ⚠️ Partial | `daemon` stored, not wired |
-| `--config=FILE` | Alternate rsyncd.conf file | ⚠️ Partial | `daemon_config` stored, not wired |
-| `--dparam=OVERRIDE` | Override global daemon config | ❌ Not Implemented | |
-| `--no-detach` | Don't detach from parent | ❌ Not Implemented | |
-| `--password-file=FILE` | Read daemon password from file | ❌ Not Implemented | |
-| `--early-input=FILE` | Use FILE for daemon early exec | ❌ Not Implemented | |
-
-## 15. Safety & Security
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| Path escape detection | Ensure files stay within root | ✅ Implemented | `has_path_traversal()` + realpath |
-| Symlink-safe delete | Skip symlinks in delete walk | ✅ Implemented | `delete_extras_walk()` |
-| Protocol version check | Verify compatible versions | ✅ Implemented | `config_receive()` |
-| Max data/string/chunk sizes | Prevent OOM attacks | ✅ Implemented | Per-message limits |
-| Per-connection memory limit | 1GB per connection | ✅ Implemented | `MAX_CONNECTION_MEMORY` |
-| `--trust-sender` | Trust remote sender's file list | ❌ Not Implemented | |
-| `--old-args` | Disable modern arg protection | ❌ Not Implemented | |
-| `--ignore-missing-args` | Ignore missing source args | ❌ Not Implemented | |
-| `--delete-missing-args` | Delete missing source args | ❌ Not Implemented | |
-
-## 16. Batch Operations
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--write-batch=FILE` | Write batched update to file | ❌ Not Implemented | |
-| `--only-write-batch=FILE` | Write batch without updating dest | ❌ Not Implemented | |
-| `--read-batch=FILE` | Read batched update from file | ❌ Not Implemented | |
-
-## 17. Advanced
-
-| Flag | Rsync Description | FastSync Status | Notes |
-|------|-------------------|-----------------|-------|
-| `--stop-after=MINS` | Stop after N minutes | ❌ Not Implemented | |
-| `--stop-at=TIME` | Stop at specified time | ❌ Not Implemented | |
-| `--fsync` | Fsync every written file | ❌ Not Implemented | |
-| `--protocol=NUM` | Force older protocol version | ❌ Not Implemented | |
-| `--iconv=CONVERT_SPEC` | Charset conversion | ❌ Not Implemented | |
-| `--checksum-seed=NUM` | Set checksum seed | ❌ Not Implemented | |
-| `-s`, `--secluded-args` | Use protocol to send args | ❌ Not Implemented | |
-| `--no-OPTION` | Turn off implied option | ❌ Not Implemented | |
-
----
-
-## Recommendations: Top Features to Implement Next
-
-Ranked by user demand, implementation complexity, and interoperability impact:
-
-| Priority | Feature | Effort | Impact |
-|----------|---------|--------|--------|
-| 1 | `--whole-file` / `-W` | Low | High — users expect opt-out of delta |
-| 2 | `--ignore-times` / `-I` | Low | Medium — useful for forcing re-transfer |
-| 3 | `--size-only` | Low | Medium — common migration scenario |
-| 4 | `--existing` / `--ignore-existing` | Low | Medium — common sync patterns |
-| 5 | `--remove-source-files` | Low | High — common for moves/backup |
-| 6 | `--delete-during` | Medium | High — performance improvement |
-| 7 | `--delay-updates` | Medium | High — atomic updates |
-| 8 | `--chmod` | Low | Medium — permission flexibility |
-| 9 | `--executability` / `-E` | Low | Low — simple flag |
-| 10 | `--skip-compress` | Low | Medium — performance tuning |
-
----
-
-## FastSync-Specific Features (Not in rsync)
-
-| Feature | Description |
-|---------|-------------|
-| `-m` | Multithreaded pipeline (scanner/loader/sender) |
-| `-s` | Chunk serialization mode |
-| `-f` / `--sendfile` | Zero-copy sendfile() syscall (TCP only) |
-| `-c [level]` | zstd compression level (1-22) |
-| `--chunk-size` | Configurable chunk size |
-| `--queue-size` | Pipeline queue capacity |
-| `--tls` | TLS encryption (mutual auth) |
-| `--fastsync-server-path` | Path to fastsync-server binary |
-| `--server-host` / `--server-port` | Direct TCP connection |
-| Incremental sync | Skip unchanged files (size+mtime) |
-| Delta transfer | Block-level delta for changed files |

src/client/client_cli.c

@@ -3,7 +3,6 @@
 #include "delta.h"
 #include "log.h"
 #include "protocol.h"
-#include "transport_tcp.h"
 #include "transport_tls.h"
 #include "utils.h"
 #include <errno.h>
@@ -12,53 +11,80 @@
 #include <stdlib.h>
 #include <string.h>
 
-/* Parse environment variables for source/destination directories and save-to-disk flag. */
+static void print_usage(void) {
-static void parse_environment(const char** out_env_source, const char** out_env_dest,
+  printf("Usage:\n");
-                              bool* out_save_to_disk) {
+  printf("  fastsync [options] <source> <destination>\n");
-  *out_env_source = getenv("FASTSYNC_SOURCE_DIR");
+  printf("  fastsync [options] --source-dir <src> --dest-dir <dst>\n");
-  *out_env_dest = getenv("FASTSYNC_DEST_DIR");
+  printf("\n");
+  printf("Destination formats:\n");
+  printf("  user@host:/path     SSH transport (rsync-style)\n");
+  printf("  host:/path          SSH transport (current user)\n");
+  printf("  /local/path         TCP transport (requires server on localhost:8080)\n");
+  printf("\n");
+  printf("Options:\n");
+  printf("  -c [level]          Enable compression (level 1-22, default 5)\n");
+  printf("  -z [level]          Alias for -c\n");
+  printf("  -a, --archive       Archive mode (-c -m -M)\n");
+  printf("  -n, --dry-run       Show what would be transferred\n");
+  printf("  -p <port>           SSH port (default: 22)\n");
+  printf("  --progress          Show transfer progress\n");
+  printf("  --delete            Delete files on receiver not in source\n");
+  printf("  --exclude <pattern> Exclude files matching pattern\n");
+  printf("  --include <pattern> Only include files matching pattern\n");
+  printf("  --max-size <n>      Skip files larger than n bytes\n");
+  printf("  --min-size <n>      Skip files smaller than n bytes\n");
+  printf("  --incremental       Skip files unchanged since last transfer\n");
+  printf("  --delta             Delta transfer for changed files (requires --incremental)\n");
+  printf("  --delta-block <n>   Delta block size in bytes (default: %d)\n",
+         DELTA_BLOCK_SIZE_DEFAULT);
+  printf("  --delta-max <n>     Max file size for delta transfer (default: %llu)\n",
+         DELTA_MAX_FILE_SIZE);
+  printf("  -m                  Enable multithreading\n");
+  printf("  -s                  Enable chunk serialization\n");
+  printf("  -f                  Enable sendfile (TCP only, not with -c or -s)\n");
+  printf("  -v, --verbose       Enable debug logging\n");
+  printf("  -M, --preserve      Preserve file metadata\n");
+  printf("  --chunk-size <n>    Chunk size in bytes (default: %d)\n", DEFAULT_CHUNK_SIZE);
+  printf("  --source-dir <path> Source directory\n");
+  printf("  --dest-dir <path>   Destination directory\n");
+  printf("  --save-to-disk      Write received files to disk\n");
+  printf("  --server-host <ip>  Server IP address (default: 127.0.0.1)\n");
+  printf("  --server-port <n>   Server port (default: 8080)\n");
+  printf("  --bwlimit <KB/s>    Bandwidth limit in kilobytes per second\n");
+  printf("  --tls               Enable TLS encryption\n");
+  printf("  --cert <path>       TLS certificate file (PEM)\n");
+  printf("  --key <path>        TLS private key file (PEM)\n");
+  printf("  --ca <path>         TLS CA certificate file (PEM)\n");
+  printf("  --partial           Keep partial files on interrupted transfer\n");
+  printf("  --help              Show this help\n");
+  printf("  -V, --version       Show version and exit\n");
+}
+
+int main(int argc, char* argv[]) {
+  const char* env_source = getenv("FASTSYNC_SOURCE_DIR");
+  const char* env_dest = getenv("FASTSYNC_DEST_DIR");
   const char* env_save = getenv("FASTSYNC_SAVE_TO_DISK");
-  *out_save_to_disk = false;
-  if (env_save && (strcmp(env_save, "true") == 0 || strcmp(env_save, "1") == 0))
-    *out_save_to_disk = true;
-}
 
-/* Parse a string as a positive integer, returning true on success. */
+  bool save_to_disk = false;
-static bool parse_positive_int(const char* s, int* out_val) {
+  if (env_save && (strcmp(env_save, "true") == 0 || strcmp(env_save, "1") == 0)) {
-  if (!s || *s == '\0')
+    save_to_disk = true;
-    return false;
+  }
-  char* endptr;
-  errno = 0;
-  long val = strtol(s, &endptr, 10);
-  if (errno != 0 || *endptr != '\0' || val <= 0 || val > INT_MAX)
-    return false;
-  *out_val = (int)val;
-  return true;
-}
 
-/* Parse a string as a non-negative integer, returning true on success. */
+  Config* config = config_create(str_dup(PROTOCOL_VERSION), NULL, NULL, save_to_disk, false, false,
-static bool parse_nonneg_int(const char* s, int* out_val) {
+                                 false, false, 5, false, 0);
-  if (!s || *s == '\0')
+  int exit_code = 0;
-    return false;
+  bool config_owned_by_pipeline = false;
-  char* endptr;
-  errno = 0;
-  long val = strtol(s, &endptr, 10);
-  if (errno != 0 || *endptr != '\0' || val < 0 || val > INT_MAX)
-    return false;
-  *out_val = (int)val;
-  return true;
-}
 
-static void print_usage(void);
+  int positional_args[2];
-static int read_patterns_from_file(const char* filepath, char*** patterns, int* count);
+  int positional_count = 0;
 
-/* Parse CLI arguments into config. Returns 0 on success, -1 on error, 1 for help/clean-exit. */
-static int parse_args(Config* config, int argc, char* argv[], int* positional_args,
-                      int* positional_count) {
   for (int i = 1; i < argc; i++) {
     if (strcmp(argv[i], "--help") == 0) {
       print_usage();
-      return 1;
+      goto cleanup;
+    } else if (strcmp(argv[i], "-V") == 0 || strcmp(argv[i], "--version") == 0) {
+      printf("fastsync version %s\n", PROTOCOL_VERSION);
+      goto cleanup;
     } else if (strcmp(argv[i], "-a") == 0 || strcmp(argv[i], "--archive") == 0) {
       config->use_compression = true;
       config->use_multithreading = true;
@@ -67,38 +93,34 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "-n") == 0 || strcmp(argv[i], "--dry-run") == 0) {
       config->dry_run = true;
     } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
-      if (!parse_positive_int(argv[++i], &config->ssh_port)) {
+      char* end;
-        fprintf(stderr, "Error: invalid --port/-p value: %s\n", argv[i]);
+      long p = strtol(argv[++i], &end, 10);
-        return -1;
+      if (*end != '\0' || p <= 0 || p > 65535) {
+        fprintf(stderr, "Error: invalid SSH port '%s' (must be 1-65535)\n", argv[i]);
+        exit_code = 1;
+        goto cleanup;
       }
+      config->ssh_port = (int)p;
     } else if (strcmp(argv[i], "--delete") == 0) {
       config->use_delete = true;
     } else if (strcmp(argv[i], "--exclude") == 0 && i + 1 < argc) {
       char** tmp = realloc(config->exclude_patterns, (config->exclude_count + 1) * sizeof(char*));
       if (!tmp) {
         fprintf(stderr, "Error: memory allocation failed for --exclude\n");
-        return -1;
+        exit_code = 1;
+        goto cleanup;
       }
       config->exclude_patterns = tmp;
-      char* dup = str_dup(argv[++i]);
+      config->exclude_patterns[config->exclude_count++] = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --exclude\n");
-        return -1;
-      }
-      config->exclude_patterns[config->exclude_count++] = dup;
     } else if (strcmp(argv[i], "--include") == 0 && i + 1 < argc) {
       char** tmp = realloc(config->include_patterns, (config->include_count + 1) * sizeof(char*));
       if (!tmp) {
         fprintf(stderr, "Error: memory allocation failed for --include\n");
-        return -1;
+        exit_code = 1;
+        goto cleanup;
       }
       config->include_patterns = tmp;
-      char* dup = str_dup(argv[++i]);
+      config->include_patterns[config->include_count++] = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --include\n");
-        return -1;
-      }
-      config->include_patterns[config->include_count++] = dup;
     } else if (strcmp(argv[i], "--max-size") == 0 && i + 1 < argc) {
       config->max_size = strtoull(argv[++i], NULL, 10);
     } else if (strcmp(argv[i], "--min-size") == 0 && i + 1 < argc) {
@@ -124,29 +146,19 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       log_message(LOG_LEVEL_INFO, "Enabled Compression");
       if (i + 1 < argc) {
         char* end_ptr;
-        long level = strtol(argv[i + 1], &end_ptr, 10);
+        int level = strtol(argv[i + 1], &end_ptr, 10);
         if (*end_ptr == '\0') {
-          config->compression_level = (int)level;
+          config->compression_level = level;
-          log_message(LOG_LEVEL_INFO, "Set Compression level to %ld", level);
+          log_message(LOG_LEVEL_INFO, "Set Compression level to %d", config->compression_level);
           i++;
         }
       }
     } else if (strcmp(argv[i], "--source-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --source-dir\n");
-        return -1;
-      }
       free(config->send_directory);
-      config->send_directory = dup;
+      config->send_directory = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--dest-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --dest-dir\n");
-        return -1;
-      }
       free(config->receive_root_directory);
-      config->receive_root_directory = dup;
+      config->receive_root_directory = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--save-to-disk") == 0) {
       config->save_to_disk = true;
     } else if (strcmp(argv[i], "-M") == 0 || strcmp(argv[i], "--preserve") == 0) {
@@ -162,29 +174,30 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       config->use_chunk_serialization = true;
       log_message(LOG_LEVEL_INFO, "Enabled Chunk Serialization");
     } else if (strcmp(argv[i], "--server-host") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --server-host\n");
-        return -1;
-      }
       free(config->server_host);
-      config->server_host = dup;
+      config->server_host = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--server-port") == 0 && i + 1 < argc) {
-      if (!parse_positive_int(argv[++i], &config->server_port)) {
+      char* end;
-        fprintf(stderr, "Error: invalid --server-port value: %s\n", argv[i]);
+      long p = strtol(argv[++i], &end, 10);
-        return -1;
+      if (*end != '\0' || p <= 0 || p > 65535) {
+        fprintf(stderr, "Error: invalid server port '%s' (must be 1-65535)\n", argv[i]);
+        exit_code = 1;
+        goto cleanup;
       }
+      config->server_port = (int)p;
     } else if (strcmp(argv[i], "--bwlimit") == 0 && i + 1 < argc) {
       char* end;
       errno = 0;
       unsigned long long kbps = strtoull(argv[++i], &end, 10);
       if (errno != 0 || *end != '\0' || kbps == 0) {
         fprintf(stderr, "Error: --bwlimit must be a positive integer\n");
-        return -1;
+        exit_code = 1;
+        goto cleanup;
       }
       if (kbps > ULLONG_MAX / 1024) {
         fprintf(stderr, "Error: --bwlimit value too large\n");
-        return -1;
+        exit_code = 1;
+        goto cleanup;
       }
       io_set_bwlimit(kbps * 1024);
       log_message(LOG_LEVEL_INFO, "Set bandwidth limit to %llu KB/s", kbps);
@@ -197,537 +210,42 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "--tls") == 0) {
       config->use_tls = true;
     } else if (strcmp(argv[i], "--cert") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --cert\n");
-        return -1;
-      }
       free(config->tls_cert);
-      config->tls_cert = dup;
+      config->tls_cert = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --key\n");
-        return -1;
-      }
       free(config->tls_key);
-      config->tls_key = dup;
+      config->tls_key = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --ca\n");
-        return -1;
-      }
       free(config->tls_ca);
-      config->tls_ca = dup;
+      config->tls_ca = str_dup(argv[++i]);
-    } else if (strcmp(argv[i], "--timeout") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --timeout must be a positive integer\n");
-        return -1;
-      }
-      config->timeout = val;
-    } else if (strcmp(argv[i], "--contimeout") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --contimeout must be a positive integer\n");
-        return -1;
-      }
-      config->contimeout = val;
-    } else if (strcmp(argv[i], "-q") == 0 || strcmp(argv[i], "--quiet") == 0 ||
-               strcmp(argv[i], "--silent") == 0) {
-      config->quiet = true;
-    } else if (strcmp(argv[i], "--backup") == 0) {
-      config->backup = true;
-    } else if (strcmp(argv[i], "--backup-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --backup-dir\n");
-        return -1;
-      }
-      free(config->backup_dir);
-      config->backup_dir = dup;
-    } else if (strcmp(argv[i], "--stats") == 0) {
-      config->stats = true;
-    } else if (strcmp(argv[i], "--max-depth") == 0 && i + 1 < argc) {
-      if (!parse_nonneg_int(argv[++i], &config->max_depth)) {
-        fprintf(stderr, "Error: --max-depth must be a non-negative integer\n");
-        return -1;
-      }
-    } else if (strcmp(argv[i], "--log-file") == 0 && i + 1 < argc) {
-      FILE* lf = fopen(argv[++i], "a");
-      if (!lf) {
-        fprintf(stderr, "Error: could not open log file '%s': %s\n", argv[i], strerror(errno));
-        return -1;
-      }
-      config->log_file = lf;
-      log_set_file(lf);
-    } else if (strcmp(argv[i], "--queue-size") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --queue-size must be a positive integer\n");
-        return -1;
-      }
-      config->queue_size = val;
-    } else if (strcmp(argv[i], "--exclude-from") == 0 && i + 1 < argc) {
-      if (read_patterns_from_file(argv[++i], &config->exclude_patterns, &config->exclude_count) !=
-          0)
-        return -1;
-    } else if (strcmp(argv[i], "--include-from") == 0 && i + 1 < argc) {
-      if (read_patterns_from_file(argv[++i], &config->include_patterns, &config->include_count) !=
-          0)
-        return -1;
     } else if (strcmp(argv[i], "--partial") == 0) {
       config->partial = true;
-    } else if (strcmp(argv[i], "--fastsync-server-path") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --fastsync-server-path\n");
-        return -1;
-      }
-      free(config->fastsync_server_path);
-      config->fastsync_server_path = dup;
     } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
       set_log_level(LOG_LEVEL_DEBUG);
-    } else if (strcmp(argv[i], "-l") == 0 || strcmp(argv[i], "--links") == 0) {
-      config->follow_symlinks = true;
-    } else if (strcmp(argv[i], "--copy-links") == 0) {
-      config->copy_links = true;
-    } else if (strcmp(argv[i], "--safe-links") == 0) {
-      config->safe_links = true;
-    } else if (strcmp(argv[i], "--copy-unsafe-links") == 0) {
-      config->copy_unsafe_links = true;
-    } else if (strcmp(argv[i], "-H") == 0 || strcmp(argv[i], "--hard-links") == 0) {
-      config->preserve_hard_links = true;
-    } else if (strcmp(argv[i], "-A") == 0 || strcmp(argv[i], "--acls") == 0) {
-      config->preserve_acls = true;
-    } else if (strcmp(argv[i], "-X") == 0 || strcmp(argv[i], "--xattrs") == 0) {
-      config->preserve_xattrs = true;
-    } else if (strcmp(argv[i], "-D") == 0 || strcmp(argv[i], "--devices") == 0) {
-      config->preserve_devices = true;
-    } else if (strcmp(argv[i], "-S") == 0 || strcmp(argv[i], "--sparse") == 0) {
-      config->preserve_sparse = true;
-    } else if (strcmp(argv[i], "-i") == 0 || strcmp(argv[i], "--itemize-changes") == 0) {
-      config->itemize_changes = true;
-    } else if (strcmp(argv[i], "--out-format") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->out_format);
-      config->out_format = dup;
-    } else if (strcmp(argv[i], "--info") == 0 && i + 1 < argc) {
-      config->info_level = atoi(argv[++i]);
-    } else if (strcmp(argv[i], "--debug") == 0 && i + 1 < argc) {
-      config->debug_level = atoi(argv[++i]);
-    } else if (strcmp(argv[i], "--list-only") == 0) {
-      config->list_only = true;
-    } else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--human-readable") == 0) {
-      config->human_readable = true;
-    } else if (strcmp(argv[i], "-u") == 0 || strcmp(argv[i], "--update") == 0) {
-      config->update = true;
-    } else if (strcmp(argv[i], "--inplace") == 0) {
-      config->inplace = true;
-    } else if (strcmp(argv[i], "--append") == 0) {
-      config->append = true;
-    } else if (strcmp(argv[i], "--append-verify") == 0) {
-      config->append_verify = true;
-    } else if (strcmp(argv[i], "--delete-excluded") == 0) {
-      config->delete_excluded = true;
-    } else if (strcmp(argv[i], "--delete-after") == 0) {
-      config->delete_after = true;
-    } else if (strcmp(argv[i], "--max-delete") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_nonneg_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --max-delete must be a non-negative integer\n");
-        return -1;
-      }
-      config->max_delete = val;
-    } else if (strcmp(argv[i], "--filter") == 0 && i + 1 < argc) {
-      if (!config->filters)
-        config->filters = array_list_create(free);
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      array_list_add(config->filters, dup);
-    } else if (strcmp(argv[i], "--files-from") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->files_from);
-      config->files_from = dup;
-    } else if (strcmp(argv[i], "--cvs-exclude") == 0) {
-      config->cvs_exclude = true;
-    } else if (strcmp(argv[i], "--prune-empty-dirs") == 0) {
-      config->prune_empty_dirs = true;
-    } else if (strcmp(argv[i], "-R") == 0 || strcmp(argv[i], "--relative") == 0) {
-      config->relative = true;
-    } else if (strcmp(argv[i], "-e") == 0 || strcmp(argv[i], "--rsh") == 0) {
-      if (i + 1 < argc) {
-        char* dup = str_dup(argv[++i]);
-        if (!dup)
-          return -1;
-        free(config->rsh_command);
-        config->rsh_command = dup;
-      } else {
-        fprintf(stderr, "Error: -e/--rsh requires a command argument\n");
-        return -1;
-      }
-    } else if (strcmp(argv[i], "--rsync-path") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->rsync_path);
-      config->rsync_path = dup;
-    } else if (strcmp(argv[i], "--temp-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->temp_dir);
-      config->temp_dir = dup;
-    } else if (strcmp(argv[i], "--compare-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->compare_dest);
-      config->compare_dest = dup;
-    } else if (strcmp(argv[i], "--copy-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->copy_dest);
-      config->copy_dest = dup;
-    } else if (strcmp(argv[i], "--link-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->link_dest);
-      config->link_dest = dup;
-    } else if (strcmp(argv[i], "--partial-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --partial-dir\n");
-        return -1;
-      }
-      free(config->partial_dir);
-      config->partial_dir = dup;
-    } else if (strcmp(argv[i], "--suffix") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --suffix\n");
-        return -1;
-      }
-      free(config->suffix);
-      config->suffix = dup;
-    } else if (strcmp(argv[i], "--delete-before") == 0) {
-      config->delete_before = true;
-    } else if (strcmp(argv[i], "-T") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: -T must be a positive integer\n");
-        return -1;
-      }
-      config->timeout = val;
-    } else if (strcmp(argv[i], "--address") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->address);
-      config->address = dup;
-    } else if (strcmp(argv[i], "--bind-address") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->bind_address);
-      config->bind_address = dup;
-    } else if (strcmp(argv[i], "--ipv6") == 0) {
-      config->ipv6 = true;
-    } else if (strcmp(argv[i], "--ipv4") == 0) {
-      config->ipv4 = true;
-    } else if (strcmp(argv[i], "--daemon") == 0) {
-      config->daemon = true;
-    } else if (strcmp(argv[i], "--config") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->daemon_config);
-      config->daemon_config = dup;
-    } else if (strcmp(argv[i], "--server") == 0) {
-      config->server_mode = true;
-    } else if (strcmp(argv[i], "--checksum") == 0) {
-      config->checksum = true;
-    } else if (strcmp(argv[i], "--compress-choice") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
-        return -1;
-      free(config->compress_choice);
-      config->compress_choice = dup;
-      if (strcmp(config->compress_choice, "zstd") == 0)
-        config->use_compression = true;
-      else if (strcmp(config->compress_choice, "none") == 0)
-        config->use_compression = false;
-      else {
-        fprintf(stderr, "Error: --compress-choice must be 'zstd' or 'none'\n");
-        return -1;
-      }
-    } else if (strcmp(argv[i], "--compress-level") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --compress-level must be a positive integer\n");
-        return -1;
-      }
-      config->compression_level = val;
     } else if (argv[i][0] == '-') {
       fprintf(stderr, "Unknown option: %s\n", argv[i]);
       print_usage();
-      return -1;
+      exit_code = 1;
+      goto cleanup;
     } else {
-      if (*positional_count < 2)
+      if (positional_count < 2)
-        positional_args[(*positional_count)++] = i;
+        positional_args[positional_count++] = i;
       else {
         fprintf(stderr, "Unexpected argument: %s\n", argv[i]);
         print_usage();
-        return -1;
+        exit_code = 1;
+        goto cleanup;
       }
     }
   }
-  return 0;
-}
 
-/* Validate config after parsing. Returns true if valid. */
-static bool validate_config(const Config* config) {
-  if (!config->send_directory || !config->receive_root_directory) {
-    fprintf(stderr, "Error: source and destination directories are required\n");
-    print_usage();
-    return false;
-  }
-  if (config->use_sendfile && (config->use_chunk_serialization || config->use_compression)) {
-    fprintf(stderr, "Error: -f/--sendfile cannot be combined with -c (compression) or -s (chunk "
-                    "serialization)\n");
-    return false;
-  }
-  if (config->transport == TRANSPORT_SSH && config->use_sendfile) {
-    fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
-    return false;
-  }
-  if (config->use_incremental && config->use_chunk_serialization) {
-    fprintf(stderr, "Error: --incremental is not supported with -s (chunk serialization)\n");
-    return false;
-  }
-  if (config->use_delta && !config->use_incremental) {
-    fprintf(stderr, "Error: --delta requires --incremental\n");
-    return false;
-  }
-  if (config->use_delta && config->use_chunk_serialization) {
-    fprintf(stderr, "Error: --delta cannot be combined with -s (chunk serialization)\n");
-    return false;
-  }
-  if (config->use_delta && config->use_sendfile) {
-    fprintf(stderr, "Error: --delta cannot be combined with -f (sendfile)\n");
-    return false;
-  }
-  if (config->append || config->append_verify) {
-    fprintf(
-        stderr,
-        "Error: --append and --append-verify are not supported yet; refusing to ignore option\n");
-    return false;
-  }
-  if (config->use_tls) {
-    if (!config->tls_cert || !config->tls_key) {
-      fprintf(stderr, "Error: --tls requires --cert and --key\n");
-      return false;
-    }
-  }
-  return true;
-}
-
-static void print_usage(void) {
-  printf("Usage:\n");
-  printf("  fastsync [options] <source> <destination>\n");
-  printf("  fastsync [options] --source-dir <src> --dest-dir <dst>\n");
-  printf("\n");
-  printf("Destination formats:\n");
-  printf("  user@host:/path     SSH transport (rsync-style)\n");
-  printf("  host:/path          SSH transport (current user)\n");
-  printf("  /local/path         TCP transport (requires server on localhost:8080)\n");
-  printf("\n");
-  printf("Options:\n");
-  printf("  -c [level]          Enable compression (level 1-22, default 5)\n");
-  printf("  -z [level]          Alias for -c\n");
-  printf("  -a, --archive       Archive mode (-c -m -M)\n");
-  printf("  -n, --dry-run       Show what would be transferred\n");
-  printf("  -p <port>           SSH port (default: 22)\n");
-  printf("  --progress          Show transfer progress\n");
-  printf("  --delete            Delete files on receiver not in source\n");
-  printf("  --exclude <pattern> Exclude files matching pattern\n");
-  printf("  --include <pattern> Only include files matching pattern\n");
-  printf("  --exclude-from <file> Read exclude patterns from file\n");
-  printf("  --include-from <file> Read include patterns from file\n");
-  printf("  --max-size <n>      Skip files larger than n bytes\n");
-  printf("  --min-size <n>      Skip files smaller than n bytes\n");
-  printf("  --incremental       Skip files unchanged since last transfer\n");
-  printf("  --delta             Delta transfer for changed files (requires --incremental)\n");
-  printf("  --delta-block <n>   Delta block size in bytes (default: %d)\n",
-         DELTA_BLOCK_SIZE_DEFAULT);
-  printf("  --delta-max <n>     Max file size for delta transfer (default: %llu)\n",
-         DELTA_MAX_FILE_SIZE);
-  printf("  -m                  Enable multithreading\n");
-  printf("  -s                  Enable chunk serialization\n");
-  printf("  -f                  Enable sendfile (TCP only, not with -c or -s)\n");
-  printf("  -v, --verbose       Enable debug logging\n");
-  printf("  -M, --preserve      Preserve file metadata\n");
-  printf("  --chunk-size <n>    Chunk size in bytes (default: %d)\n", DEFAULT_CHUNK_SIZE);
-  printf("  --source-dir <path> Source directory\n");
-  printf("  --dest-dir <path>   Destination directory\n");
-  printf("  --save-to-disk      Write received files to disk\n");
-  printf("  --server-host <ip>  Server IP address (default: 127.0.0.1)\n");
-  printf("  --server-port <n>   Server port (default: 8080)\n");
-  printf("  --bwlimit <KB/s>    Bandwidth limit in kilobytes per second\n");
-  printf("  --tls               Enable TLS encryption\n");
-  printf("  --cert <path>       TLS certificate file (PEM)\n");
-  printf("  --key <path>        TLS private key file (PEM)\n");
-  printf("  --ca <path>         TLS CA certificate file (PEM)\n");
-  printf("  --timeout <sec>     I/O timeout in seconds (default: 30)\n");
-  printf("  -T <sec>            Alias for --timeout\n");
-  printf("  --contimeout <sec>  Connection timeout in seconds (default: 10)\n");
-  printf("  --address <host>    Server hostname/IP to connect to\n");
-  printf("  --bind-address <ip> Bind to specific local address\n");
-  printf("  --ipv6              Prefer IPv6 connections\n");
-  printf("  --ipv4              Prefer IPv4 connections\n");
-  printf("  -q, --quiet         Suppress non-error output\n");
-  printf("  --silent            Alias for --quiet\n");
-  printf("  --backup            Backup existing files before overwriting\n");
-  printf("  --backup-dir <dir>  Directory for backups (requires --backup)\n");
-  printf("  --suffix <str>      Backup suffix (default: ~)\n");
-  printf("  --stats             Print transfer statistics at end\n");
-  printf("  --max-depth <n>     Maximum directory depth (0=unlimited)\n");
-  printf("  --log-file <path>   Write log messages to file\n");
-  printf("  --queue-size <n>    Queue capacity for multithreaded mode (default: 100)\n");
-  printf("  --partial           Keep partial files on interrupted transfer\n");
-  printf("  --partial-dir <dir> Directory for partial files\n");
-  printf("  --fastsync-server-path <path>\n");
-  printf("                      Path to fastsync-server on remote (default: fastsync-server)\n");
-  printf("  -l, --links         Copy symlinks as symlinks\n");
-  printf("  --copy-links        Transform symlinks into referent files\n");
-  printf("  --safe-links        Skip symlinks that point outside transfer tree\n");
-  printf("  --copy-unsafe-links  Only transform unsafe symlinks into referent files\n");
-  printf("  -H, --hard-links    Preserve hard links\n");
-  printf("  -A, --acls          Preserve ACLs\n");
-  printf("  -X, --xattrs        Preserve extended attributes\n");
-  printf("  -D, --devices       Preserve device files\n");
-  printf("  -S, --sparse        Handle sparse files efficiently\n");
-  printf("  -i, --itemize-changes  Show per-file change summary\n");
-  printf("  --out-format <fmt>  Custom output format string\n");
-  printf("  --info <flags>      Info verbosity level\n");
-  printf("  --debug <flags>     Debug verbosity level\n");
-  printf("  --list-only         List files without transferring\n");
-  printf("  -h, --human-readable  Human-readable numbers\n");
-  printf("  -u, --update        Skip files newer on destination\n");
-  printf("  --inplace           Update files in-place (no temp+rename)\n");
-  printf("  --append            Append data to shorter files\n");
-  printf("  --append-verify     Append with verify\n");
-  printf("  --delete-before     Delete before transfer\n");
-  printf("  --delete-excluded   Also delete excluded files\n");
-  printf("  --delete-after      Delete after transfer, not before\n");
-  printf("  --max-delete <n>    Maximum number of files to delete\n");
-  printf("  --filter <rule>     Add file filtering rule\n");
-  printf("  --files-from <file> Read file list from file\n");
-  printf("  --cvs-exclude       Auto-ignore CVS files\n");
-  printf("  --prune-empty-dirs  Omit empty directories from transfer\n");
-  printf("  -R, --relative      Use relative paths\n");
-  printf("  -e, --rsh <cmd>     Specify remote shell\n");
-  printf("  --rsync-path <path> Path to remote binary\n");
-  printf("  --daemon            Run in daemon mode\n");
-  printf("  --config <path>     Path to configuration file\n");
-  printf("  --server            Run in server mode\n");
-  printf("  --checksum          Skip files based on checksum, not mod-time/size\n");
-  printf("  --compress-choice <alg>  Compression algorithm (default: zstd)\n");
-  printf("  --compress-level <n>    Compression level (default: 5)\n");
-  printf("  --temp-dir <dir>    Temporary directory for files\n");
-  printf("  --compare-dest <dir>  Compare destination\n");
-  printf("  --copy-dest <dir>   Copy destination\n");
-  printf("  --link-dest <dir>   Link destination\n");
-  printf("  --help              Show this help\n");
-}
-
-static int read_patterns_from_file(const char* filepath, char*** patterns, int* count) {
-  FILE* fp = fopen(filepath, "r");
-  if (!fp) {
-    fprintf(stderr, "Error: could not open pattern file '%s': %s\n", filepath, strerror(errno));
-    return -1;
-  }
-  char line[4096];
-  while (fgets(line, sizeof(line), fp)) {
-    char* p = line;
-    while (*p == ' ' || *p == '\t')
-      p++;
-    if (*p == '#' || *p == '\n' || *p == '\0')
-      continue;
-    size_t len = strlen(p);
-    while (len > 0 && (p[len - 1] == '\n' || p[len - 1] == '\r'))
-      p[--len] = '\0';
-    if (len == 0)
-      continue;
-    char** tmp = realloc(*patterns, (*count + 1) * sizeof(char*));
-    if (!tmp) {
-      fprintf(stderr, "Error: memory allocation failed for pattern file\n");
-      fclose(fp);
-      return -1;
-    }
-    *patterns = tmp;
-    char* dup = str_dup(p);
-    if (!dup) {
-      fprintf(stderr, "Error: memory allocation failed for pattern file\n");
-      fclose(fp);
-      return -1;
-    }
-    (*patterns)[(*count)++] = dup;
-  }
-  fclose(fp);
-  return 0;
-}
-
-int main(int argc, char* argv[]) {
-  const char* env_source = NULL;
-  const char* env_dest = NULL;
-  bool save_to_disk = false;
-  parse_environment(&env_source, &env_dest, &save_to_disk);
-
-  int exit_code = 0;
-  bool config_owned_by_pipeline = false;
-  Config* config = config_create();
-  if (!config) {
-    fprintf(stderr, "Error: failed to allocate config\n");
-    return 1;
-  }
-  config->save_to_disk = save_to_disk;
-
-  int positional_args[2];
-  int positional_count = 0;
-
-  int parse_ret = parse_args(config, argc, argv, positional_args, &positional_count);
-  if (parse_ret != 0) {
-    if (parse_ret < 0)
-      exit_code = 1;
-    goto cleanup;
-  }
-
-  /* Handle positional arguments or fall back to environment variables */
   if (positional_count == 2) {
     free(config->send_directory);
     free(config->receive_root_directory);
     config->send_directory = str_dup(argv[positional_args[0]]);
-    if (!config->send_directory) {
-      fprintf(stderr, "Error: memory allocation failed\n");
-      exit_code = 1;
-      goto cleanup;
-    }
     config->receive_root_directory = str_dup(argv[positional_args[1]]);
-    if (!config->receive_root_directory) {
-      fprintf(stderr, "Error: memory allocation failed\n");
-      exit_code = 1;
-      goto cleanup;
-    }
     config->save_to_disk = true;
+
     config_parse_ssh_dest(config);
   } else if (positional_count == 1) {
     fprintf(stderr, "Error: missing destination argument\n");
@@ -735,46 +253,71 @@ int main(int argc, char* argv[]) {
     exit_code = 1;
     goto cleanup;
   } else {
-    if (!config->send_directory && env_source) {
+    if (!config->send_directory && env_source)
-      config->send_directory = str_dup(env_source);
+      config->send_directory = str_dup((char*)env_source);
-      if (!config->send_directory) {
+    if (!config->receive_root_directory && env_dest)
-        fprintf(stderr, "Error: memory allocation failed\n");
+      config->receive_root_directory = str_dup((char*)env_dest);
-        exit_code = 1;
-        goto cleanup;
-      }
-    }
-    if (!config->receive_root_directory && env_dest) {
-      config->receive_root_directory = str_dup(env_dest);
-      if (!config->receive_root_directory) {
-        fprintf(stderr, "Error: memory allocation failed\n");
-        exit_code = 1;
-        goto cleanup;
-      }
-    }
   }
 
-  if (!validate_config(config)) {
+  if (!config->send_directory || !config->receive_root_directory) {
+    fprintf(stderr, "Error: source and destination directories are required\n");
+    print_usage();
+    exit_code = 1;
+    goto cleanup;
+  }
+  if (config->use_sendfile && (config->use_chunk_serialization || config->use_compression)) {
+    fprintf(stderr, "Error: -f/--sendfile cannot be combined with -c (compression) or -s (chunk "
+                    "serialization)\n");
+    exit_code = 1;
+    goto cleanup;
+  }
+
+  if (config->transport == TRANSPORT_SSH && config->use_sendfile) {
+    fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
+    exit_code = 1;
+    goto cleanup;
+  }
+
+  if (config->use_incremental && config->use_chunk_serialization) {
+    fprintf(stderr, "Error: --incremental is not supported with -s (chunk serialization)\n");
     exit_code = 1;
     goto cleanup;
   }
 
-  /* Enable implicit flags */
   if (config->use_incremental && !config->use_metadata) {
     log_message(LOG_LEVEL_INFO, "Enabling metadata preservation for --incremental");
     config->use_metadata = true;
   }
+
+  if (config->use_delta && !config->use_incremental) {
+    fprintf(stderr, "Error: --delta requires --incremental\n");
+    exit_code = 1;
+    goto cleanup;
+  }
+  if (config->use_delta && config->use_chunk_serialization) {
+    fprintf(stderr, "Error: --delta cannot be combined with -s (chunk serialization)\n");
+    exit_code = 1;
+    goto cleanup;
+  }
+  if (config->use_delta && config->use_sendfile) {
+    fprintf(stderr, "Error: --delta cannot be combined with -f (sendfile)\n");
+    exit_code = 1;
+    goto cleanup;
+  }
   if (config->use_delta && !config->use_metadata) {
     log_message(LOG_LEVEL_INFO, "Enabling metadata preservation for --delta");
     config->use_metadata = true;
   }
 
-  /* Initialize TLS if needed */
+  if (config->use_tls) {
-  if (config->use_tls)
+    if (!config->tls_cert || !config->tls_key) {
+      fprintf(stderr, "Error: --tls requires --cert and --key\n");
+      exit_code = 1;
+      goto cleanup;
+    }
     tls_global_init();
+  }
 
-  tcp_set_timeouts(config->timeout, config->contimeout);
-
-  /* Execute transfer */
   if (config->use_multithreading) {
     config_owned_by_pipeline = true;
     exit_code = send_files_multithreaded(config);
@@ -783,11 +326,7 @@ int main(int argc, char* argv[]) {
   }
 
 cleanup:
-  if (config) {
+  if (!config_owned_by_pipeline)
-    if (config->log_file)
+    config_delete(config);
-      fclose(config->log_file);
-    if (!config_owned_by_pipeline)
-      config_delete(config);
-  }
   return exit_code;
 }

src/client/client_send.c

@@ -21,54 +21,8 @@
 #include <string.h>
 #include <threads.h>
 #include <time.h>
-#include <unistd.h>
 
-#define STREAM_THRESHOLD (64ULL * 1024 * 1024)
+static int incremental_check(Client* client, File* file, DeltaSignature** out_sig) {
-
-/* Forward declaration for progress-reporting thread used in multithreaded send. */
-static int progress_thread_fn(void* arg);
-
-/* Print dry-run manifest showing files that would be transferred. Returns 0 on success. */
-static int send_dry_run_manifest(Config* config) {
-  DirectoryScanner* scanner = directory_scanner_create(
-      config->send_directory, config->use_metadata, config->chunk_size, config->exclude_patterns,
-      config->exclude_count, config->include_patterns, config->include_count, config->max_size,
-      config->min_size, config->max_depth, config->follow_symlinks, config->copy_links,
-      config->safe_links, config->copy_unsafe_links, config->checksum);
-  if (!scanner)
-    return -1;
-  Chunk* chunk;
-  int file_count = 0;
-  unsigned long long total_bytes = 0;
-  printf("Dry run: files to be transferred\n");
-  while ((chunk = directory_scanner_next(scanner)) != NULL) {
-    for (int i = 0; i < chunk->element_count; i++) {
-      printf("  %s (%zu bytes)\n", chunk->items[i]->path, chunk->items[i]->data->size);
-      total_bytes += chunk->items[i]->data->size;
-      file_count++;
-    }
-    chunk_destroy(chunk);
-  }
-  directory_scanner_destroy(scanner);
-  printf("Total: %d files, %.1f MB\n", file_count, total_bytes / 1048576.0);
-  return 0;
-}
-
-/* Send the delete manifest (list of files) to the server. Returns 0 on success, -1 on failure. */
-static int send_delete_manifest(int fd, ArrayList* manifest) {
-  if (!send_status(fd, STATUS_MANIFEST))
-    return -1;
-  if (!send_int(fd, manifest->size))
-    return -1;
-  for (int i = 0; i < manifest->size; i++) {
-    if (!send_str(fd, (char*)manifest->items[i]))
-      return -1;
-  }
-  return 0;
-}
-
-static int incremental_check(Client* client, File* file, const Config* config,
-                             DeltaSignature** out_sig) {
   *out_sig = NULL;
   if (!send_status(client->file_descriptor, STATUS_CHECK))
     return -1;
@@ -80,12 +34,6 @@ static int incremental_check(Client* client, File* file, const Config* config,
     return -1;
   if (!send_n_data(client->file_descriptor, &mtime, sizeof(mtime)))
     return -1;
-  if (config->checksum) {
-    uint64_t checksum;
-    if (!file_checksum(file, &checksum) ||
-        !send_n_data(client->file_descriptor, &checksum, sizeof(checksum)))
-      return -1;
-  }
   Status s;
   if (!receive_status(client->file_descriptor, &s))
     return -1;
@@ -183,7 +131,7 @@ static int send_single_file(Client* client, File* file, Config* config, bool use
   // Incremental path: use sendfile for the actual data if enabled and no compression
   if (use_sendfile) {
     DeltaSignature* sig = NULL;
-    int rc = incremental_check(client, file, config, &sig);
+    int rc = incremental_check(client, file, &sig);
     if (rc == 1) {
       delta_signature_destroy(sig);
       return 1;
@@ -209,7 +157,7 @@ static int send_single_file(Client* client, File* file, Config* config, bool use
   // Incremental path with single_calls (supports compression and delta)
   file_send_fn send_fn = (file_send_fn)file_send_single_calls;
   DeltaSignature* sig = NULL;
-  int rc = incremental_check(client, file, config, &sig);
+  int rc = incremental_check(client, file, &sig);
   if (rc < 0) {
     delta_signature_destroy(sig);
     return -1;
@@ -260,13 +208,10 @@ int send_chunk(Client* client, Chunk* chunk, Config* config) {
     return 0;
   }
 
+  bool use_sendfile = config->use_sendfile && !config->use_compression;
   for (int i = 0; i < chunk->element_count; i++) {
-    File* f = chunk->items[i];
+    int rc =
-    if (f == NULL)
+        send_single_file(client, chunk->items[i], config, config->use_incremental, use_sendfile);
-      continue;
-    bool stream = f->data->data == NULL && f->data->size > 0;
-    bool use_sendfile = (config->use_sendfile && !config->use_compression) || stream;
-    int rc = send_single_file(client, f, config, config->use_incremental, use_sendfile);
     if (rc == 1)
       continue;
     if (rc < 0)
@@ -281,13 +226,9 @@ static int send_chunks_multithreaded(void* pipeline_context) {
   if (context->config->transport == TRANSPORT_SSH) {
     if (context->config->use_sendfile) {
       fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return 1;
     }
-    client = client_connect_ssh(context->config->ssh_destination, context->config->ssh_port,
+    client = client_connect_ssh(context->config->ssh_destination, context->config->ssh_port);
-                                context->config->fastsync_server_path);
   } else if (context->config->use_tls) {
     client = client_create();
     if (!client || !client_connect_tls(client, context->config->server_host,
@@ -296,9 +237,6 @@ static int send_chunks_multithreaded(void* pipeline_context) {
       if (client)
         client_delete(client);
       fprintf(stderr, "Error: could not connect to server via TLS\n");
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return thrd_error;
     }
   } else {
@@ -308,18 +246,12 @@ static int send_chunks_multithreaded(void* pipeline_context) {
       if (client)
         client_delete(client);
       fprintf(stderr, "Error: could not connect to server\n");
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return thrd_error;
     }
   }
   if (!config_send(client->file_descriptor, context->config)) {
     client_disconnect(client);
     client_delete(client);
-    mtx_lock(&context->mutex_progress);
-    context->sender_done = true;
-    mtx_unlock(&context->mutex_progress);
     return thrd_error;
   }
 
@@ -329,8 +261,14 @@ static int send_chunks_multithreaded(void* pipeline_context) {
         &context->condition_not_full_loader, &context->loader_done);
     if (current_chunk == NULL) {
       if (context->config->use_delete) {
-        if (send_delete_manifest(client->file_descriptor, context->manifest) != 0)
+        if (!send_status(client->file_descriptor, STATUS_MANIFEST))
           goto send_fail;
+        if (!send_int(client->file_descriptor, context->manifest->size))
+          goto send_fail;
+        for (int i = 0; i < context->manifest->size; i++) {
+          if (!send_str(client->file_descriptor, (char*)context->manifest->items[i]))
+            goto send_fail;
+        }
       }
       if (!send_status(client->file_descriptor, STATUS_FINISHED))
         goto send_fail;
@@ -338,54 +276,35 @@ static int send_chunks_multithreaded(void* pipeline_context) {
       int ok = receive_status(client->file_descriptor, &s) && s == STATUS_OK;
       client_disconnect(client);
       client_delete(client);
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return ok ? thrd_success : thrd_error;
 
     send_fail:
       client_disconnect(client);
       client_delete(client);
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return thrd_error;
     }
     if (send_chunk(client, current_chunk, context->config) != 0) {
       fprintf(stderr, "Error: unexpected error while sending chunk\n");
       client_disconnect(client);
       client_delete(client);
-      mtx_lock(&context->mutex_progress);
-      context->sender_done = true;
-      mtx_unlock(&context->mutex_progress);
       return thrd_error;
     }
-    if (context->config->show_progress) {
-      unsigned long long chunk_bytes = 0;
-      for (int i = 0; i < current_chunk->element_count; i++) {
-        if (current_chunk->items[i] && current_chunk->items[i]->data)
-          chunk_bytes += current_chunk->items[i]->data->size;
-      }
-      mtx_lock(&context->mutex_progress);
-      context->progress_bytes += chunk_bytes;
-      mtx_unlock(&context->mutex_progress);
-    }
     chunk_destroy(current_chunk);
   }
 }
 
 static int scan_directory_multithreaded(void* pipeline_context) {
   PipelineContextSender* context = (PipelineContextSender*)pipeline_context;
-  ParallelScanner* scanner = parallel_scanner_create(
+  mtx_lock(&context->mutex_scanner);
+  DirectoryScanner* scanner = directory_scanner_create(
       context->config->send_directory, context->config->use_metadata, context->config->chunk_size,
       context->config->exclude_patterns, context->config->exclude_count,
       context->config->include_patterns, context->config->include_count, context->config->max_size,
-      context->config->min_size, context->config->max_depth, 4, context->config->follow_symlinks,
+      context->config->min_size);
-      context->config->copy_links, context->config->safe_links, context->config->copy_unsafe_links,
+  mtx_unlock(&context->mutex_scanner);
-      context->config->checksum);
 
   Chunk* current_chunk;
-  while ((current_chunk = parallel_scanner_next(scanner)) != NULL) {
+  while ((current_chunk = directory_scanner_next(scanner)) != NULL) {
     if (context->config->use_delete) {
       mtx_lock(&context->mutex_scanner);
       for (int i = 0; i < current_chunk->element_count; i++) {
@@ -405,7 +324,7 @@ static int scan_directory_multithreaded(void* pipeline_context) {
   cnd_signal(&context->condition_not_empty_scanner);
   mtx_unlock(&context->mutex_scanner);
 
-  parallel_scanner_destroy(scanner);
+  directory_scanner_destroy(scanner);
   return thrd_success;
 }
 
@@ -424,12 +343,9 @@ static int load_files_multithreaded(void* pipeline_context) {
     }
     if (!context->config->use_sendfile) {
       for (int i = 0; i < chunk->element_count; i++) {
-        File* f = chunk->items[i];
+        if (!file_load_data(chunk->items[i])) {
-        if (f->data->size > STREAM_THRESHOLD)
-          continue;
-        if (!file_load_data(f)) {
           log_message(LOG_LEVEL_ERROR, "Failed to load file data, skipping");
-          file_destroy(f);
+          file_destroy(chunk->items[i]);
           chunk->items[i] = NULL;
         }
       }
@@ -440,45 +356,28 @@ static int load_files_multithreaded(void* pipeline_context) {
   }
 }
 
-/* Progress-reporting thread for multithreaded send. Runs in parallel with
-   the scanner/loader/sender threads and prints periodic progress to stderr. */
-static int progress_thread_fn(void* arg) {
-  PipelineContextSender* context = (PipelineContextSender*)arg;
-  time_t last_progress = 0;
-  time_t start = time(NULL);
-
-  while (true) {
-    mtx_lock(&context->mutex_progress);
-    bool done = context->sender_done;
-    unsigned long long total = context->progress_bytes;
-    mtx_unlock(&context->mutex_progress);
-
-    if (done) {
-      time_t now = time(NULL);
-      double elapsed = difftime(now, start);
-      double rate = elapsed > 0.0 ? total / (1048576.0 * elapsed) : 0.0;
-      fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  Done.\n", total / 1048576.0, rate);
-      break;
-    }
-
-    time_t now = time(NULL);
-    if (now - last_progress >= 1) {
-      last_progress = now;
-      double elapsed = difftime(now, start);
-      double rate = elapsed > 0.0 ? total / (1048576.0 * elapsed) : 0.0;
-      fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  ", total / 1048576.0, rate);
-      fflush(stderr);
-    }
-
-    struct timespec ts = {0, 100 * 1000000L}; /* 100 ms */
-    thrd_sleep(&ts, NULL);
-  }
-  return thrd_success;
-}
-
 int send_files(Config* config) {
-  if (config->dry_run)
+  if (config->dry_run) {
-    return send_dry_run_manifest(config);
+    DirectoryScanner* scanner = directory_scanner_create(
+        config->send_directory, config->use_metadata, config->chunk_size, config->exclude_patterns,
+        config->exclude_count, config->include_patterns, config->include_count, config->max_size,
+        config->min_size);
+    Chunk* chunk;
+    int file_count = 0;
+    unsigned long long total_bytes = 0;
+    printf("Dry run: files to be transferred\n");
+    while ((chunk = directory_scanner_next(scanner)) != NULL) {
+      for (int i = 0; i < chunk->element_count; i++) {
+        printf("  %s (%zu bytes)\n", chunk->items[i]->path, chunk->items[i]->data->size);
+        total_bytes += chunk->items[i]->data->size;
+        file_count++;
+      }
+      chunk_destroy(chunk);
+    }
+    directory_scanner_destroy(scanner);
+    printf("Total: %d files, %.1f MB\n", file_count, total_bytes / 1048576.0);
+    return 0;
+  }
 
   Client* client;
   if (config->transport == TRANSPORT_SSH) {
@@ -486,8 +385,7 @@ int send_files(Config* config) {
       fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
       return 1;
     }
-    client =
+    client = client_connect_ssh(config->ssh_destination, config->ssh_port);
-        client_connect_ssh(config->ssh_destination, config->ssh_port, config->fastsync_server_path);
     if (!client)
       return 1;
   } else if (config->use_tls) {
@@ -516,11 +414,9 @@ int send_files(Config* config) {
   DirectoryScanner* scanner = directory_scanner_create(
       config->send_directory, config->use_metadata, config->chunk_size, config->exclude_patterns,
       config->exclude_count, config->include_patterns, config->include_count, config->max_size,
-      config->min_size, config->max_depth, config->follow_symlinks, config->copy_links,
+      config->min_size);
-      config->safe_links, config->copy_unsafe_links, config->checksum);
   Chunk* current_chunk;
   unsigned long long total_bytes = 0;
-  int total_files = 0;
   time_t last_progress = 0;
   time_t start = time(NULL);
   ArrayList* manifest = config->use_delete ? array_list_create(free) : NULL;
@@ -528,7 +424,6 @@ int send_files(Config* config) {
     unsigned long long chunk_bytes = 0;
     for (int i = 0; i < current_chunk->element_count; i++) {
       chunk_bytes += current_chunk->items[i]->data->size;
-      total_files++;
       if (manifest) {
         const char* p = current_chunk->items[i]->path;
         if (*p == '/')
@@ -538,10 +433,7 @@ int send_files(Config* config) {
     }
     if (!config->use_sendfile) {
       for (int i = 0; i < current_chunk->element_count; i++) {
-        File* f = current_chunk->items[i];
+        if (!file_load_data(current_chunk->items[i])) {
-        if (f->data->size > STREAM_THRESHOLD)
-          continue;
-        if (!file_load_data(f)) {
           log_message(LOG_LEVEL_ERROR, "Failed to load file data");
           continue;
         }
@@ -566,56 +458,68 @@ int send_files(Config* config) {
     chunk_destroy(current_chunk);
   }
   if (config->use_delete) {
-    if (send_delete_manifest(client->file_descriptor, manifest) != 0) {
+    if (!send_status(client->file_descriptor, STATUS_MANIFEST)) {
       array_list_delete(manifest);
       goto send_fail;
     }
+    if (!send_int(client->file_descriptor, manifest->size)) {
+      array_list_delete(manifest);
+      goto send_fail;
+    }
+    for (int i = 0; i < manifest->size; i++) {
+      if (!send_str(client->file_descriptor, (char*)manifest->items[i])) {
+        array_list_delete(manifest);
+        goto send_fail;
+      }
+    }
     array_list_delete(manifest);
   }
   if (!send_status(client->file_descriptor, STATUS_FINISHED))
     goto send_fail;
   Status s;
   int ok = receive_status(client->file_descriptor, &s) && s == STATUS_OK;
-  double elapsed_total = difftime(time(NULL), start);
   if (config->show_progress) {
-    double rate = elapsed_total > 0 ? total_bytes / (1048576.0 * elapsed_total) : 0;
+    double elapsed = difftime(time(NULL), start);
+    double rate = elapsed > 0 ? total_bytes / (1048576.0 * elapsed) : 0;
     fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  Done.\n", total_bytes / 1048576.0, rate);
   }
-  if (config->stats) {
-    double rate = elapsed_total > 0 ? total_bytes / (1048576.0 * elapsed_total) : 0;
-    fprintf(stderr, "Stats: %d files, %.1f MB, %.1f MB/s\n", total_files, total_bytes / 1048576.0,
-            rate);
-  }
   directory_scanner_destroy(scanner);
   client_disconnect(client);
   client_delete(client);
-  return ok ? 0 : 1;
+  return ok ? 0 : -1;
 
 send_fail:
   directory_scanner_destroy(scanner);
   client_disconnect(client);
   client_delete(client);
-  return 1;
+  return -1;
 }
 
 int send_files_multithreaded(Config* config) {
-  if (config->dry_run)
+  if (config->dry_run) {
-    return send_dry_run_manifest(config);
+    DirectoryScanner* scanner = directory_scanner_create(
+        config->send_directory, config->use_metadata, config->chunk_size, config->exclude_patterns,
+        config->exclude_count, config->include_patterns, config->include_count, config->max_size,
+        config->min_size);
+    Chunk* chunk;
+    int file_count = 0;
+    unsigned long long total_bytes = 0;
+    printf("Dry run: files to be transferred\n");
+    while ((chunk = directory_scanner_next(scanner)) != NULL) {
+      for (int i = 0; i < chunk->element_count; i++) {
+        printf("  %s (%zu bytes)\n", chunk->items[i]->path, chunk->items[i]->data->size);
+        total_bytes += chunk->items[i]->data->size;
+        file_count++;
+      }
+      chunk_destroy(chunk);
+    }
+    directory_scanner_destroy(scanner);
+    printf("Total: %d files, %.1f MB\n", file_count, total_bytes / 1048576.0);
+    return 0;
+  }
 
-  long pages = sysconf(_SC_AVPHYS_PAGES);
+  Queue* q1 = queue_create(100, chunk_destroy);
-  long page_size = sysconf(_SC_PAGE_SIZE);
+  Queue* q2 = queue_create(100, chunk_destroy);
-  unsigned long long available_memory =
-      pages > 0 && page_size > 0 ? (unsigned long long)pages * (unsigned long long)page_size
-                                 : 512ULL * 1024 * 1024;
-  unsigned long long avg_file_size = 1024 * 1024;
-  int qsize = (int)(available_memory / avg_file_size);
-  if (qsize < 10)
-    qsize = 10;
-  if (qsize > 1000)
-    qsize = 1000;
-
-  Queue* q1 = queue_create(qsize, chunk_destroy);
-  Queue* q2 = queue_create(qsize, chunk_destroy);
   if (!q1 || !q2) {
     if (q1)
       queue_destroy(q1);
@@ -632,7 +536,7 @@ int send_files_multithreaded(Config* config) {
   if (config->use_delete)
     context->manifest = array_list_create(free);
 
-  thrd_t scanner, loader, sender, progress;
+  thrd_t scanner, loader, sender;
   if (thrd_create(&scanner, scan_directory_multithreaded, context) != thrd_success ||
       thrd_create(&loader, load_files_multithreaded, context) != thrd_success ||
       thrd_create(&sender, send_chunks_multithreaded, context) != thrd_success) {
@@ -641,26 +545,11 @@ int send_files_multithreaded(Config* config) {
     return 1;
   }
 
-  if (config->show_progress) {
-    if (thrd_create(&progress, progress_thread_fn, context) != thrd_success) {
-      perror("Error creating progress thread.\n");
-      /* Non-fatal; continue without progress reporting */
-    }
-  }
-
   int sender_result;
   thrd_join(scanner, NULL);
   thrd_join(loader, NULL);
   thrd_join(sender, &sender_result);
 
-  if (config->show_progress) {
-    /* Signal progress thread to exit if it hasn't already */
-    mtx_lock(&context->mutex_progress);
-    context->sender_done = true;
-    mtx_unlock(&context->mutex_progress);
-    thrd_join(progress, NULL);
-  }
-
   pipeline_context_sender_destroy(context);
-  return sender_result == thrd_success ? 0 : 1;
+  return sender_result == thrd_success ? 0 : -1;
 }

src/client/scanner.c

@@ -9,60 +9,89 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
-#include <threads.h>
 #include <unistd.h>
 
-typedef struct {
+DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metadata,
-  char* path;
-  int depth;
-} DirEntry;
-
-static void dir_entry_destroy(void* item) {
-  if (item) {
-    DirEntry* de = (DirEntry*)item;
-    free(de->path);
-    free(de);
-  }
-}
-
-static DirEntry* dir_entry_create(const char* path, int depth) {
-  DirEntry* de = malloc(sizeof(DirEntry));
-  if (de) {
-    de->path = str_dup(path);
-    de->depth = depth;
-  }
-  return de;
-}
-
-DirectoryScanner* directory_scanner_create(const char* root_directory, bool use_metadata,
                                            unsigned long long chunk_size, char** exclude_patterns,
                                            int exclude_count, char** include_patterns,
                                            int include_count, unsigned long long max_size,
-                                           unsigned long long min_size, int max_depth,
+                                           unsigned long long min_size) {
-                                           bool follow_symlinks, bool copy_links, bool safe_links,
+  return directory_scanner_create_full(root_directory, use_metadata, chunk_size, exclude_patterns,
-                                           bool copy_unsafe_links, bool checksum) {
+                                       exclude_count, include_patterns, include_count, max_size,
+                                       min_size, true);
+}
+
+DirectoryScanner* directory_scanner_create_full(char* root_directory, bool use_metadata,
+                                                unsigned long long chunk_size,
+                                                char** exclude_patterns, int exclude_count,
+                                                char** include_patterns, int include_count,
+                                                unsigned long long max_size,
+                                                unsigned long long min_size, bool follow_symlinks) {
   DirectoryScanner* scanner = malloc(sizeof(DirectoryScanner));
   if (scanner == NULL)
     return NULL;
-  scanner->directories = queue_create(100, dir_entry_destroy);
+  scanner->directories = queue_create(100, free);
   scanner->current_dir = NULL;
   scanner->current_path = NULL;
   scanner->use_metadata = use_metadata;
   scanner->chunk_size = chunk_size > 0 ? chunk_size : DESIRED_CHUNK_SIZE;
-  scanner->exclude_patterns = exclude_patterns;
+  /* Deep-copy exclude patterns */
+  if (exclude_count > 0 && exclude_patterns != NULL) {
+    scanner->exclude_patterns = malloc((size_t)exclude_count * sizeof(char*));
+    if (scanner->exclude_patterns == NULL) {
+      queue_destroy(scanner->directories);
+      free(scanner);
+      return NULL;
+    }
+    for (int i = 0; i < exclude_count; i++) {
+      scanner->exclude_patterns[i] = str_dup(exclude_patterns[i]);
+      if (scanner->exclude_patterns[i] == NULL) {
+        for (int j = 0; j < i; j++)
+          free(scanner->exclude_patterns[j]);
+        free(scanner->exclude_patterns);
+        queue_destroy(scanner->directories);
+        free(scanner);
+        return NULL;
+      }
+    }
+  } else {
+    scanner->exclude_patterns = NULL;
+  }
   scanner->exclude_count = exclude_count;
-  scanner->include_patterns = include_patterns;
+
+  /* Deep-copy include patterns */
+  if (include_count > 0 && include_patterns != NULL) {
+    scanner->include_patterns = malloc((size_t)include_count * sizeof(char*));
+    if (scanner->include_patterns == NULL) {
+      for (int i = 0; i < exclude_count; i++)
+        free(scanner->exclude_patterns[i]);
+      free(scanner->exclude_patterns);
+      queue_destroy(scanner->directories);
+      free(scanner);
+      return NULL;
+    }
+    for (int i = 0; i < include_count; i++) {
+      scanner->include_patterns[i] = str_dup(include_patterns[i]);
+      if (scanner->include_patterns[i] == NULL) {
+        for (int j = 0; j < i; j++)
+          free(scanner->include_patterns[j]);
+        free(scanner->include_patterns);
+        for (int j = 0; j < exclude_count; j++)
+          free(scanner->exclude_patterns[j]);
+        free(scanner->exclude_patterns);
+        queue_destroy(scanner->directories);
+        free(scanner);
+        return NULL;
+      }
+    }
+  } else {
+    scanner->include_patterns = NULL;
+  }
   scanner->include_count = include_count;
   scanner->max_size = max_size;
   scanner->min_size = min_size;
-  scanner->max_depth = max_depth;
-  scanner->current_depth = 0;
   scanner->follow_symlinks = follow_symlinks;
-  scanner->copy_links = copy_links;
+  queue_enqueue(scanner->directories, str_dup(root_directory));
-  scanner->safe_links = safe_links;
-  scanner->copy_unsafe_links = copy_unsafe_links;
-  scanner->checksum = checksum;
-  queue_enqueue(scanner->directories, dir_entry_create(root_directory, 0));
   return scanner;
 }
 
@@ -74,6 +103,12 @@ void directory_scanner_destroy(DirectoryScanner* scanner) {
     scanner->current_dir = NULL;
   }
   free(scanner->current_path);
+  for (int i = 0; i < scanner->exclude_count; i++)
+    free(scanner->exclude_patterns[i]);
+  free(scanner->exclude_patterns);
+  for (int i = 0; i < scanner->include_count; i++)
+    free(scanner->include_patterns[i]);
+  free(scanner->include_patterns);
   queue_destroy(scanner->directories);
   free(scanner);
 }
@@ -87,6 +122,7 @@ static Chunk* chunk_data_to_chunk(ArrayList* chunk_data) {
   return chunk;
 }
 
+// Returns: 1 on success, 0 if no more directories in queue, -1 on opendir failure
 static int open_next_directory(DirectoryScanner* scanner) {
   if (scanner->current_dir) {
     closedir(scanner->current_dir);
@@ -97,10 +133,7 @@ static int open_next_directory(DirectoryScanner* scanner) {
   if (queue_is_empty(scanner->directories))
     return 0;
 
-  DirEntry* de = (DirEntry*)queue_dequeue(scanner->directories);
+  scanner->current_path = (char*)queue_dequeue(scanner->directories);
-  scanner->current_path = de->path;
-  scanner->current_depth = de->depth;
-  free(de);
   scanner->current_dir = opendir(scanner->current_path);
   if (scanner->current_dir == NULL) {
     perror("Could not open directory");
@@ -138,72 +171,82 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner) {
 
     char* cur_path = path_cat(scanner->current_path, entry->d_name);
     struct stat stats;
-    struct stat lstats;
+    // Use lstat to detect symlinks
-    bool is_symlink = false;
+    if (lstat(cur_path, &stats) != 0) {
-    if (lstat(cur_path, &lstats) != 0) {
-      free(cur_path);
-      continue;
-    }
-    is_symlink = S_ISLNK(lstats.st_mode);
-
-    if (is_symlink && !scanner->follow_symlinks && !scanner->copy_links && !scanner->safe_links &&
-        !scanner->copy_unsafe_links) {
       free(cur_path);
       continue;
     }
 
-    if (is_symlink && scanner->safe_links) {
+    // If follow_symlinks is enabled and this is a symlink, resolve it
-      char link_target[4096];
+    if (scanner->follow_symlinks && S_ISLNK(stats.st_mode)) {
-      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
+      struct stat target_stats;
-      if (len < 0) {
+      if (stat(cur_path, &target_stats) != 0) {
-        free(cur_path);
+        // Broken symlink, skip
-        continue;
-      }
-      link_target[len] = '\0';
-      if (link_target[0] == '/') {
-        free(cur_path);
-        continue;
-      }
-    }
-
-    if (is_symlink && scanner->copy_unsafe_links && !scanner->copy_links) {
-      char link_target[4096];
-      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
-      if (len < 0) {
-        free(cur_path);
-        continue;
-      }
-      link_target[len] = '\0';
-      bool unsafe = (link_target[0] == '/');
-      if (!unsafe) {
-        free(cur_path);
-        continue;
-      }
-    }
-
-    bool use_lstat = is_symlink && scanner->follow_symlinks && !scanner->copy_links;
-    if (use_lstat) {
-      stats = lstats;
-    } else {
-      if (stat(cur_path, &stats) != 0) {
         free(cur_path);
         continue;
       }
+      stats = target_stats;
     }
 
     if (S_ISDIR(stats.st_mode)) {
-      int next_depth = scanner->current_depth + 1;
+      queue_enqueue(scanner->directories, (void*)cur_path);
-      if (scanner->max_depth <= 0 || next_depth < scanner->max_depth) {
+    } else if (S_ISLNK(stats.st_mode)) {
-        DirEntry* de = dir_entry_create(cur_path, next_depth);
+      // Handle symlink (not following)
-        if (!queue_enqueue(scanner->directories, de))
+      bool excluded = false;
-          dir_entry_destroy(de);
+      for (int i = 0; i < scanner->exclude_count; i++) {
+        if (glob_match(scanner->exclude_patterns[i], entry->d_name)) {
+          excluded = true;
+          break;
+        }
       }
-      free(cur_path);
+      if (excluded) {
-    } else {
-      if (scanner->max_depth > 0 && scanner->current_depth + 1 > scanner->max_depth) {
         free(cur_path);
         continue;
       }
+
+      if (scanner->include_count > 0) {
+        bool included = false;
+        for (int i = 0; i < scanner->include_count; i++) {
+          if (glob_match(scanner->include_patterns[i], entry->d_name)) {
+            included = true;
+            break;
+          }
+        }
+        if (!included) {
+          free(cur_path);
+          continue;
+        }
+      }
+
+      File* file = file_create(cur_path);
+      if (file == NULL) {
+        free(cur_path);
+        continue;
+      }
+      file->type = FILE_TYPE_SYMLINK;
+      // Read link target
+      char link_buf[4096];
+      ssize_t link_len = readlink(cur_path, link_buf, sizeof(link_buf) - 1);
+      if (link_len >= 0) {
+        link_buf[link_len] = '\0';
+        file->link_target = str_dup(link_buf);
+        if (file->link_target == NULL) {
+          file_destroy(file);
+          free(cur_path);
+          continue;
+        }
+      }
+      file->data->size = 0;
+      if (scanner->use_metadata)
+        file->metadata = file_metadata_create(&stats);
+      array_list_add(chunk_data, file);
+      chunk_data_size += 1; // small size for symlinks
+      if (chunk_data_size > scanner->chunk_size) {
+        free(cur_path);
+        return chunk_data_to_chunk(chunk_data);
+      }
+      free(cur_path);
+    } else {
       bool excluded = false;
       for (int i = 0; i < scanner->exclude_count; i++) {
         if (glob_match(scanner->exclude_patterns[i], entry->d_name)) {
@@ -259,319 +302,3 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner) {
   array_list_delete(chunk_data);
   return NULL;
 }
-
-typedef struct {
-  ParallelScanner* ps;
-  char** dirs;
-  int dir_count;
-  bool use_metadata;
-  unsigned long long chunk_size;
-  char** exclude_patterns;
-  int exclude_count;
-  char** include_patterns;
-  int include_count;
-  unsigned long long max_size;
-  unsigned long long min_size;
-  int max_depth;
-  bool follow_symlinks;
-  bool copy_links;
-  bool safe_links;
-  bool copy_unsafe_links;
-  bool checksum;
-} ParallelWorkerArg;
-
-static int parallel_worker_thread(void* arg) {
-  ParallelWorkerArg* wa = (ParallelWorkerArg*)arg;
-  for (int i = 0; i < wa->dir_count; i++) {
-    DirectoryScanner* ds = directory_scanner_create(
-        wa->dirs[i], wa->use_metadata, wa->chunk_size, wa->exclude_patterns, wa->exclude_count,
-        wa->include_patterns, wa->include_count, wa->max_size, wa->min_size, wa->max_depth,
-        wa->follow_symlinks, wa->copy_links, wa->safe_links, wa->copy_unsafe_links, wa->checksum);
-    Chunk* chunk;
-    while ((chunk = directory_scanner_next(ds)) != NULL) {
-      queue_enqueue_multithreaded(wa->ps->result_queue, chunk, &wa->ps->result_mutex,
-                                  &wa->ps->result_not_empty, &wa->ps->result_not_full);
-    }
-    directory_scanner_destroy(ds);
-    free(wa->dirs[i]);
-  }
-  ParallelScanner* ps = wa->ps;
-  free(wa->dirs);
-  free(wa);
-  mtx_lock(&ps->result_mutex);
-  ps->completed++;
-  if (ps->completed >= ps->num_threads) {
-    ps->done = true;
-    cnd_signal(&ps->result_not_empty);
-  }
-  mtx_unlock(&ps->result_mutex);
-  return thrd_success;
-}
-
-ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata,
-                                         unsigned long long chunk_size, char** exclude_patterns,
-                                         int exclude_count, char** include_patterns,
-                                         int include_count, unsigned long long max_size,
-                                         unsigned long long min_size, int max_depth,
-                                         int num_threads, bool follow_symlinks, bool copy_links,
-                                         bool safe_links, bool copy_unsafe_links, bool checksum) {
-  ParallelScanner* ps = calloc(1, sizeof(ParallelScanner));
-  if (!ps)
-    return NULL;
-  ps->result_queue = queue_create(100, chunk_destroy);
-  if (!ps->result_queue) {
-    free(ps);
-    return NULL;
-  }
-  if (mtx_init(&ps->result_mutex, mtx_plain) != thrd_success ||
-      cnd_init(&ps->result_not_empty) != thrd_success ||
-      cnd_init(&ps->result_not_full) != thrd_success) {
-    queue_destroy(ps->result_queue);
-    free(ps);
-    return NULL;
-  }
-
-  DIR* dir = opendir(root_directory);
-  if (!dir) {
-    perror("Could not open root directory for parallel scan");
-    parallel_scanner_destroy(ps);
-    return NULL;
-  }
-
-  ArrayList* root_files = array_list_create(file_destroy);
-  ArrayList* subdirs = array_list_create(free);
-  struct dirent* entry;
-  while ((entry = readdir(dir)) != NULL) {
-    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
-      continue;
-    char* cur_path = path_cat(root_directory, entry->d_name);
-    if (!cur_path)
-      continue;
-    struct stat lstats;
-    if (lstat(cur_path, &lstats) != 0) {
-      free(cur_path);
-      continue;
-    }
-    bool is_symlink = S_ISLNK(lstats.st_mode);
-
-    // Skip symlinks unless the user explicitly enabled following/copying them.
-    if (is_symlink && !follow_symlinks && !copy_links && !safe_links && !copy_unsafe_links) {
-      free(cur_path);
-      continue;
-    }
-
-    // --safe-links: reject symlinks pointing outside the source tree.
-    if (is_symlink && safe_links) {
-      char link_target[4096];
-      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
-      if (len < 0) {
-        free(cur_path);
-        continue;
-      }
-      link_target[len] = 0;
-      if (link_target[0] == '/') {
-        free(cur_path);
-        continue;
-      }
-    }
-
-    // --copy-unsafe-links (without --copy-links): only copy absolute symlinks.
-    if (is_symlink && copy_unsafe_links && !copy_links) {
-      char link_target[4096];
-      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
-      if (len < 0) {
-        free(cur_path);
-        continue;
-      }
-      link_target[len] = 0;
-      bool unsafe = (link_target[0] == '/');
-      if (!unsafe) {
-        free(cur_path);
-        continue;
-      }
-    }
-
-    // Determine whether to use lstat or stat results for the entry.
-    struct stat st;
-    bool use_lstat_res = is_symlink && follow_symlinks && !copy_links;
-    if (use_lstat_res) {
-      st = lstats;
-    } else {
-      if (stat(cur_path, &st) != 0) {
-        free(cur_path);
-        continue;
-      }
-    }
-
-    if (S_ISDIR(st.st_mode)) {
-      array_list_add(subdirs, cur_path);
-    } else {
-      bool excluded = false;
-      for (int i = 0; i < exclude_count; i++) {
-        if (glob_match(exclude_patterns[i], entry->d_name)) {
-          excluded = true;
-          break;
-        }
-      }
-      if (excluded) {
-        free(cur_path);
-        continue;
-      }
-      if (include_count > 0) {
-        bool included = false;
-        for (int i = 0; i < include_count; i++) {
-          if (glob_match(include_patterns[i], entry->d_name)) {
-            included = true;
-            break;
-          }
-        }
-        if (!included) {
-          free(cur_path);
-          continue;
-        }
-      }
-      if ((max_size > 0 && (unsigned long long)st.st_size > max_size) ||
-          (min_size > 0 && (unsigned long long)st.st_size < min_size)) {
-        free(cur_path);
-        continue;
-      }
-      File* file = file_create(cur_path);
-      free(cur_path);
-      if (!file)
-        continue;
-      file->data->size = st.st_size;
-      if (use_metadata)
-        file->metadata = file_metadata_create(&st);
-      array_list_add(root_files, file);
-    }
-  }
-  closedir(dir);
-
-  unsigned long long cs = chunk_size > 0 ? chunk_size : DESIRED_CHUNK_SIZE;
-  if (root_files->size > 0) {
-    ArrayList* batch = array_list_create(NULL);
-    unsigned long long batch_size = 0;
-    Chunk* first = NULL;
-    for (int i = 0; i < root_files->size; i++) {
-      File* f = (File*)root_files->items[i];
-      array_list_add(batch, f);
-      batch_size += f->data->size;
-      if (batch_size >= cs || i == root_files->size - 1) {
-        void** items = array_list_to_array(batch);
-        Chunk* c = chunk_create((File**)items, batch->size);
-        free(items);
-        batch->item_destroyer = NULL;
-        array_list_delete(batch);
-        batch = NULL;
-        if (!first) {
-          first = c;
-        } else {
-          queue_enqueue_multithreaded(ps->result_queue, c, &ps->result_mutex, &ps->result_not_empty,
-                                      &ps->result_not_full);
-        }
-        if (i < root_files->size - 1) {
-          batch = array_list_create(NULL);
-          batch_size = 0;
-        }
-      }
-    }
-    if (batch) {
-      batch->item_destroyer = NULL;
-      array_list_delete(batch);
-    }
-    ps->initial_chunk = first;
-    root_files->item_destroyer = NULL;
-  }
-  array_list_delete(root_files);
-
-  int n = num_threads > 0 ? num_threads : 4;
-  if (n > subdirs->size)
-    n = subdirs->size > 0 ? subdirs->size : 1;
-
-  if (subdirs->size > 0) {
-    ps->num_threads = n;
-    ps->threads = calloc(n, sizeof(thrd_t));
-    if (!ps->threads) {
-      array_list_delete(subdirs);
-      parallel_scanner_destroy(ps);
-      return NULL;
-    }
-    int dirs_per_thread = subdirs->size / n;
-    int remainder = subdirs->size % n;
-    int start = 0;
-    for (int t = 0; t < n; t++) {
-      int count = dirs_per_thread + (t < remainder ? 1 : 0);
-      if (count == 0)
-        break;
-      ParallelWorkerArg* wa = calloc(1, sizeof(ParallelWorkerArg));
-      if (!wa)
-        break;
-      wa->ps = ps;
-      wa->dirs = calloc(count, sizeof(char*));
-      if (!wa->dirs) {
-        free(wa);
-        break;
-      }
-      for (int j = 0; j < count; j++)
-        wa->dirs[j] = str_dup((char*)subdirs->items[start + j]);
-      wa->dir_count = count;
-      wa->use_metadata = use_metadata;
-      wa->chunk_size = cs;
-      wa->exclude_patterns = exclude_patterns;
-      wa->exclude_count = exclude_count;
-      wa->include_patterns = include_patterns;
-      wa->include_count = include_count;
-      wa->max_size = max_size;
-      wa->min_size = min_size;
-      wa->max_depth = max_depth;
-      wa->follow_symlinks = follow_symlinks;
-      wa->copy_links = copy_links;
-      wa->safe_links = safe_links;
-      wa->copy_unsafe_links = copy_unsafe_links;
-      wa->checksum = checksum;
-      start += count;
-      if (thrd_create(&ps->threads[t], parallel_worker_thread, wa) != thrd_success) {
-        for (int j = 0; j < count; j++)
-          free(wa->dirs[j]);
-        free(wa->dirs);
-        free(wa);
-        ps->num_threads = t;
-        break;
-      }
-    }
-  }
-  array_list_delete(subdirs);
-  return ps;
-}
-
-Chunk* parallel_scanner_next(ParallelScanner* ps) {
-  if (ps->initial_chunk) {
-    Chunk* c = ps->initial_chunk;
-    ps->initial_chunk = NULL;
-    return c;
-  }
-  if (ps->num_threads == 0) {
-    ps->done = true;
-    return NULL;
-  }
-  Chunk* chunk = queue_dequeue_multithreaded(
-      ps->result_queue, &ps->result_mutex, &ps->result_not_empty, &ps->result_not_full, &ps->done);
-  return chunk;
-}
-
-void parallel_scanner_destroy(ParallelScanner* ps) {
-  if (!ps)
-    return;
-  ps->done = true;
-  cnd_signal(&ps->result_not_empty);
-  for (int i = 0; i < ps->num_threads; i++)
-    thrd_join(ps->threads[i], NULL);
-  free(ps->threads);
-  if (ps->initial_chunk)
-    chunk_destroy(ps->initial_chunk);
-  queue_destroy(ps->result_queue);
-  mtx_destroy(&ps->result_mutex);
-  cnd_destroy(&ps->result_not_empty);
-  cnd_destroy(&ps->result_not_full);
-  free(ps);
-}

src/client/scanner.h

@@ -5,7 +5,6 @@
 #include "queue.h"
 #include <dirent.h>
 #include <stdbool.h>
-#include <threads.h>
 
 typedef struct {
   Queue* directories;
@@ -19,45 +18,21 @@ typedef struct {
   int include_count;
   unsigned long long max_size;
   unsigned long long min_size;
-  int max_depth;
-  int current_depth;
   bool follow_symlinks;
-  bool copy_links;
-  bool safe_links;
-  bool copy_unsafe_links;
-  bool checksum;
 } DirectoryScanner;
 
-typedef struct {
+DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metadata,
-  Queue* result_queue;
-  mtx_t result_mutex;
-  cnd_t result_not_empty;
-  cnd_t result_not_full;
-  int num_threads;
-  thrd_t* threads;
-  bool done;
-  int completed;
-  Chunk* initial_chunk;
-} ParallelScanner;
-
-DirectoryScanner* directory_scanner_create(const char* root_directory, bool use_metadata,
                                            unsigned long long chunk_size, char** exclude_patterns,
                                            int exclude_count, char** include_patterns,
                                            int include_count, unsigned long long max_size,
-                                           unsigned long long min_size, int max_depth,
+                                           unsigned long long min_size);
-                                           bool follow_symlinks, bool copy_links, bool safe_links,
+DirectoryScanner* directory_scanner_create_full(char* root_directory, bool use_metadata,
-                                           bool copy_unsafe_links, bool checksum);
+                                                unsigned long long chunk_size,
+                                                char** exclude_patterns, int exclude_count,
+                                                char** include_patterns, int include_count,
+                                                unsigned long long max_size,
+                                                unsigned long long min_size, bool follow_symlinks);
 Chunk* directory_scanner_next(DirectoryScanner* scanner);
 void directory_scanner_destroy(DirectoryScanner* scanner);
 
-ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata,
-                                         unsigned long long chunk_size, char** exclude_patterns,
-                                         int exclude_count, char** include_patterns,
-                                         int include_count, unsigned long long max_size,
-                                         unsigned long long min_size, int max_depth,
-                                         int num_threads, bool follow_symlinks, bool copy_links,
-                                         bool safe_links, bool copy_unsafe_links, bool checksum);
-Chunk* parallel_scanner_next(ParallelScanner* scanner);
-void parallel_scanner_destroy(ParallelScanner* scanner);
-
 #endif

src/server/server.c

@@ -11,28 +11,45 @@
 #include "transport_tls.h"
 #include "unistd.h"
 #include "utils.h"
+#include <libgen.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <limits.h>
-#include <sys/stat.h>
-#include <unistd.h>
 
-static char* authorized_root;
+// Check if a file path should be excluded based on config patterns
-static bool allow_delete;
+static bool is_excluded(const char* path, const Config* config) {
-
+  // Extract filename from path
-static bool path_is_within(const char* root, const char* path) {
+  char* path_dup = str_dup(path);
-  size_t n = strlen(root);
+  if (!path_dup)
-  return strncmp(root, path, n) == 0 && (path[n] == '\0' || path[n] == '/');
-}
-
-static bool __attribute__((unused)) configure_authorization(const char* root) {
-  char resolved[PATH_MAX];
-  if (!root || !realpath(root, resolved))
     return false;
-  authorized_root = str_dup(resolved);
+  char* fname = basename(path_dup);
-  return authorized_root != NULL;
+
+  // Check exclude patterns
+  for (int i = 0; i < config->exclude_count; i++) {
+    if (glob_match(config->exclude_patterns[i], fname)) {
+      free(path_dup);
+      return true;
+    }
+  }
+
+  // Check include patterns (if any, file must match at least one)
+  if (config->include_count > 0) {
+    bool included = false;
+    for (int i = 0; i < config->include_count; i++) {
+      if (glob_match(config->include_patterns[i], fname)) {
+        included = true;
+        break;
+      }
+    }
+    if (!included) {
+      free(path_dup);
+      return true;
+    }
+  }
+
+  free(path_dup);
+  return false;
 }
 
 int receive_files(Config* config, int fd) {
@@ -40,16 +57,7 @@ int receive_files(Config* config, int fd) {
   if (!receive_status(fd, &status))
     return -1;
 
-  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK ||
+  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK) {
-         status == STATUS_KEEPALIVE || status == STATUS_ABORT || status == STATUS_CHECK_BATCH) {
-    if (status == STATUS_KEEPALIVE) {
-      send_status(fd, STATUS_KEEPALIVE);
-      goto next;
-    }
-    if (status == STATUS_ABORT) {
-      log_message(LOG_LEVEL_INFO, "Received abort from client, cleaning up");
-      return -1;
-    }
     if (status == STATUS_CHECK) {
       bool skipped;
       File* file = receive_incremental_check(fd, config, &skipped);
@@ -57,8 +65,8 @@ int receive_files(Config* config, int fd) {
         goto next;
       if (file == NULL && !skipped)
         return -1;
-      if (config->save_to_disk)
+      if (config->save_to_disk && !is_excluded(file->path, config))
-        file_save_to_disk(config->receive_root_directory, file, config);
+        file_save_to_disk(config->receive_root_directory, file);
       file_destroy(file);
     } else if (status == STATUS_CHUNK) {
       Chunk* chunk = receive_chunk_data(fd, config);
@@ -67,38 +75,10 @@ int receive_files(Config* config, int fd) {
         return -1;
       }
       for (int i = 0; i < chunk->element_count; i++) {
-        if (config->save_to_disk)
+        if (config->save_to_disk && !is_excluded(chunk->items[i]->path, config))
-          file_save_to_disk(config->receive_root_directory, chunk->items[i], config);
+          file_save_to_disk(config->receive_root_directory, chunk->items[i]);
       }
       chunk_destroy(chunk);
-    } else if (status == STATUS_CHECK_BATCH) {
-      int count;
-      if (!receive_int(fd, &count))
-        return -1;
-      for (int i = 0; i < count; i++) {
-        char* check_path = receive_str(fd);
-        if (!check_path)
-          return -1;
-        unsigned long long check_size;
-        long long check_mtime;
-        if (!receive_n_data(fd, &check_size, sizeof(check_size)) ||
-            !receive_n_data(fd, &check_mtime, sizeof(check_mtime))) {
-          free(check_path);
-          return -1;
-        }
-        char* full_path = path_cat(config->receive_root_directory, check_path);
-        struct stat st;
-        bool has_old = full_path && lstat(full_path, &st) == 0;
-        bool match = has_old && (unsigned long long)st.st_size == check_size &&
-                     (long long)st.st_mtime == check_mtime;
-        if (match)
-          send_status(fd, STATUS_OK);
-        else
-          send_status(fd, STATUS_NEXT);
-        free(full_path);
-        free(check_path);
-      }
-      goto next;
     } else {
       File* file = file_receive(config, fd);
       if (file == NULL) {
@@ -106,8 +86,8 @@ int receive_files(Config* config, int fd) {
         send_status(fd, STATUS_ERROR);
         return -1;
       }
-      if (config->save_to_disk)
+      if (config->save_to_disk && !is_excluded(file->path, config))
-        file_save_to_disk(config->receive_root_directory, file, config);
+        file_save_to_disk(config->receive_root_directory, file);
       file_destroy(file);
     }
   next:
@@ -131,43 +111,12 @@ int receive_files(Config* config, int fd) {
 }
 
 void handler(int file_descriptor) {
-  SSL* ssl = io_get_ssl();
   Config* config = config_receive(file_descriptor);
   if (config == NULL) {
     log_message(LOG_LEVEL_ERROR, "Failed to receive config");
     close(file_descriptor);
     return;
   }
-  if (!authorized_root) {
-    log_message(LOG_LEVEL_ERROR, "No server-side destination root configured");
-    config_delete(config);
-    close(file_descriptor);
-    return;
-  }
-  char resolved_destination[PATH_MAX];
-  char* canonical_destination = realpath(config->receive_root_directory, NULL);
-  const char* destination =
-      canonical_destination ? canonical_destination : config->receive_root_directory;
-  if (has_path_traversal(destination) || !path_is_within(authorized_root, destination)) {
-    log_message(LOG_LEVEL_ERROR, "Rejected destination outside authorized root");
-    free(canonical_destination);
-    config_delete(config);
-    close(file_descriptor);
-    return;
-  }
-  if (canonical_destination)
-    snprintf(resolved_destination, sizeof(resolved_destination), "%s", canonical_destination);
-  else
-    snprintf(resolved_destination, sizeof(resolved_destination), "%s", destination);
-  free(canonical_destination);
-  free(config->receive_root_directory);
-  config->receive_root_directory = str_dup(resolved_destination);
-  if (!config->receive_root_directory) {
-    config_delete(config);
-    close(file_descriptor);
-    return;
-  }
-  config->use_delete = config->use_delete && allow_delete;
   if (config->use_multithreading) {
     Queue* q = queue_create(100, file_destroy);
     if (q == NULL) {
@@ -175,8 +124,7 @@ void handler(int file_descriptor) {
       close(file_descriptor);
       return;
     }
-    PipelineContextReceiver* context =
+    PipelineContextReceiver* context = pipeline_context_receiver_create(config, q, file_descriptor);
-        pipeline_context_receiver_create(config, q, file_descriptor, ssl);
     if (context == NULL) {
       queue_destroy(q);
       config_delete(config);
@@ -191,29 +139,22 @@ void handler(int file_descriptor) {
       close(file_descriptor);
       return;
     }
-    int receiver_result;
+    thrd_join(receiver, NULL);
-    int writer_result;
+    thrd_join(writer, NULL);
-    thrd_join(receiver, &receiver_result);
+    send_status(file_descriptor, STATUS_OK);
-    thrd_join(writer, &writer_result);
-    if (receiver_result == thrd_success && writer_result == thrd_success)
-      send_status(file_descriptor, STATUS_OK);
     pipeline_context_receiver_destroy(context);
-  } else {
+  } else
     receive_files(config, file_descriptor);
-    config_delete(config);
-  }
   close(file_descriptor);
 }
 
-#ifndef FASTSYNC_SERVER_AS_LIB
 static Server* g_server = NULL;
+static volatile sig_atomic_t g_server_cleanup_requested = 0;
 
 static void cleanup(int sig) {
   (void)sig;
-  if (g_server) {
+  server_request_shutdown();
-    server_delete(&g_server);
+  g_server_cleanup_requested = 1;
-  }
-  _exit(0);
 }
 
 static void print_server_usage(void) {
@@ -227,10 +168,9 @@ static void print_server_usage(void) {
   printf("  --cert <path>       TLS certificate file (PEM)\n");
   printf("  --key <path>        TLS private key file (PEM)\n");
   printf("  --ca <path>         TLS CA certificate file (PEM)\n");
-  printf("  --destination-root <path>  Authorized destination root (default: .)\n");
-  printf("  --allow-delete      Permit manifest deletion\n");
   printf("  -v, --verbose       Enable debug logging\n");
   printf("  --help              Show this help\n");
+  printf("  -V, --version       Show version and exit\n");
 }
 
 int main(int argc, char* argv[]) {
@@ -239,16 +179,19 @@ int main(int argc, char* argv[]) {
   char* tls_key = NULL;
   char* tls_ca = NULL;
   int port = 8080;
-  const char* destination_root = ".";
-  bool stdio_mode = false;
 
   signal(SIGPIPE, SIG_IGN);
   for (int i = 1; i < argc; i++) {
     if (strcmp(argv[i], "--help") == 0) {
       print_server_usage();
       return 0;
+    } else if (strcmp(argv[i], "-V") == 0 || strcmp(argv[i], "--version") == 0) {
+      printf("fastsync-server version %s\n", PROTOCOL_VERSION);
+      return 0;
     } else if (strcmp(argv[i], "--stdio") == 0) {
-      stdio_mode = true;
+      io_set_fds(STDIN_FILENO, STDOUT_FILENO);
+      handler(STDIN_FILENO);
+      return 0;
     } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
       set_log_level(LOG_LEVEL_DEBUG);
     } else if (strcmp(argv[i], "--tls") == 0) {
@@ -259,10 +202,6 @@ int main(int argc, char* argv[]) {
       tls_key = argv[++i];
     } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
       tls_ca = argv[++i];
-    } else if (strcmp(argv[i], "--destination-root") == 0 && i + 1 < argc) {
-      destination_root = argv[++i];
-    } else if (strcmp(argv[i], "--allow-delete") == 0) {
-      allow_delete = true;
     } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
       char* end;
       long p = strtol(argv[++i], &end, 10);
@@ -284,16 +223,6 @@ int main(int argc, char* argv[]) {
 
   signal(SIGINT, cleanup);
   signal(SIGTERM, cleanup);
-  if (!configure_authorization(destination_root)) {
-    fprintf(stderr, "Error: invalid destination root '%s'\n", destination_root);
-    return 1;
-  }
-  if (stdio_mode) {
-    io_set_fds(STDIN_FILENO, STDOUT_FILENO);
-    handler(STDIN_FILENO);
-    free(authorized_root);
-    return 0;
-  }
   g_server = server_create(port);
   if (g_server == NULL) {
     log_message(LOG_LEVEL_ERROR, "Failed to create server");
@@ -315,6 +244,11 @@ int main(int argc, char* argv[]) {
   } else {
     server_listen(g_server, handler);
   }
+
+  /* Graceful shutdown: if a signal requested cleanup, delete the server */
+  if (g_server_cleanup_requested) {
+    log_message(LOG_LEVEL_INFO, "Shutdown requested, cleaning up");
+    server_delete(&g_server);
+  }
   return 0;
 }
-#endif /* !FASTSYNC_SERVER_AS_LIB */

src/shared/chunk.c

@@ -12,9 +12,6 @@
 #include "metadata.h"
 #include "protocol.h"
 
-/* Maximum individual file data size within a chunk (64 MB) */
-#define MAX_FILE_DATA_SIZE (64ULL * 1024 * 1024)
-
 Chunk* chunk_create(File** items, int element_count) {
   Chunk* chunk = (Chunk*)malloc(sizeof(Chunk));
   if (chunk == NULL) {
@@ -160,14 +157,6 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
       return NULL;
     }
 
-    // Reject individual file data larger than the maximum allowed size.
-    if (file_data_size > MAX_FILE_DATA_SIZE) {
-      log_message(LOG_LEVEL_ERROR, "File data size %zu exceeds maximum %llu", file_data_size,
-                  (unsigned long long)MAX_FILE_DATA_SIZE);
-      array_list_delete(files);
-      return NULL;
-    }
-
     void* file_data = malloc(file_data_size);
     if (file_data == NULL) {
       perror("Could not allocate memory for file data");
@@ -221,15 +210,6 @@ Chunk* receive_chunk_data(int fd, const Config* config) {
       return NULL;
     }
   }
-
-  // Reject chunks larger than the maximum allowed size to prevent OOM.
-  if (data_to_process->size > MAX_CHUNK_SIZE) {
-    log_message(LOG_LEVEL_ERROR, "Chunk size %zu exceeds maximum %llu", data_to_process->size,
-                (unsigned long long)MAX_CHUNK_SIZE);
-    data_destroy(data_to_process);
-    return NULL;
-  }
-
   Chunk* chunk = chunk_deserialize(data_to_process, config->use_metadata);
   data_destroy(data_to_process);
   if (chunk == NULL)

src/shared/compression.c

@@ -1,31 +1,26 @@
 #include "compression.h"
 #include "data.h"
 #include "log.h"
-#include "stdlib.h"
+#include <stdint.h>
-#include "string.h"
+#include <stdlib.h>
-#include <strings.h>
 #include "zstd.h"
 
 #define INITIAL_DECOMPRESS_BUF_SIZE (1024 * 1024)
 
-static const char* SKIP_COMPRESSION_EXTENSIONS[] = {".jpg", ".jpeg", ".png", ".gif", ".mp4", ".mkv",
-                                                    ".zip", ".gz",   ".xz",  ".zst", NULL};
-
-bool compression_should_skip(const char* path) {
-  if (!path)
-    return false;
-  const char* dot = strrchr(path, '.');
-  if (!dot)
-    return false;
-  for (int i = 0; SKIP_COMPRESSION_EXTENSIONS[i]; i++) {
-    if (strcasecmp(dot, SKIP_COMPRESSION_EXTENSIONS[i]) == 0)
-      return true;
-  }
-  return false;
-}
-
 Data* data_compress(Data* data_to_compress, int compression_level) {
   log_message(LOG_LEVEL_DEBUG, "Starting to compress data");
+
+  /* Clamp compression level to valid zstd range [1, 22] */
+  if (compression_level < 1) {
+    log_message(LOG_LEVEL_WARNING, "compression_level %d out of range [1,22], using 1",
+                compression_level);
+    compression_level = 1;
+  } else if (compression_level > 22) {
+    log_message(LOG_LEVEL_WARNING, "compression_level %d out of range [1,22], using 22",
+                compression_level);
+    compression_level = 22;
+  }
+
   size_t dst_size = ZSTD_compressBound(data_to_compress->size);
   Data* compressed_data = data_create_empty(dst_size);
   if (compressed_data == NULL)
@@ -78,21 +73,22 @@ Data* data_decompress(Data* compressed_data) {
     return NULL;
   }
 
-  // ZSTD_CONTENTSIZE_UNKNOWN (~2^64) can cause massive allocation;
-  // fall back to a conservative estimate (3x compressed size) when unknown.
-  if (dst_size == ZSTD_CONTENTSIZE_UNKNOWN) {
-    dst_size = compressed_data->size * 3;
-    if (dst_size < INITIAL_DECOMPRESS_BUF_SIZE)
-      dst_size = INITIAL_DECOMPRESS_BUF_SIZE;
-  }
-
   ZSTD_DCtx* dctx = ZSTD_createDCtx();
   if (!dctx) {
     log_message(LOG_LEVEL_ERROR, "Failed to create ZSTD decompression context");
     return NULL;
   }
 
-  size_t buf_size = (dst_size > 0) ? (size_t)dst_size : INITIAL_DECOMPRESS_BUF_SIZE;
+  size_t buf_size = INITIAL_DECOMPRESS_BUF_SIZE;
+  if (!ZSTD_isError(dst_size) && dst_size > 0) {
+    if (dst_size > SIZE_MAX) {
+      log_message(LOG_LEVEL_ERROR,
+                  "Decompressed size %llu exceeds addressable memory, using fallback buffer",
+                  dst_size);
+    } else {
+      buf_size = (size_t)dst_size;
+    }
+  }
   Data* uncompressed_data = data_create_empty(buf_size);
   if (!uncompressed_data) {
     log_message(LOG_LEVEL_ERROR, "Failed to allocate decompression buffer");

src/shared/compression.h

@@ -2,10 +2,8 @@
 #define COMPRESSION_H
 
 #include "data.h"
-#include <stdbool.h>
 
 Data* data_compress(Data* data_to_compress, int compression_level);
 Data* data_decompress(Data* compressed_data);
-bool compression_should_skip(const char* path);
 
 #endif

src/shared/config.c

@@ -4,32 +4,36 @@
 #include "protocol.h"
 #include "utils.h"
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-Config* config_create(void) {
+Config* config_create(char* version, char* send_directory, char* receive_directory,
+                      bool save_to_disk, bool use_multithreading, bool use_chunk_serialization,
+                      bool use_compression, bool use_metadata, int compression_level,
+                      bool use_sendfile, unsigned long long chunk_size) {
+
   Config* config = malloc(sizeof(Config));
-  if (!config)
+  if (config == NULL)
     return NULL;
-  config->version = str_dup(PROTOCOL_VERSION);
+  config->version = version;
-  config->send_directory = NULL;
+  config->send_directory = send_directory;
-  config->receive_root_directory = NULL;
+  config->receive_root_directory = receive_directory;
-  config->save_to_disk = false;
+  config->save_to_disk = save_to_disk;
-  config->use_multithreading = false;
+  config->use_multithreading = use_multithreading;
-  config->use_chunk_serialization = false;
+  config->use_chunk_serialization = use_chunk_serialization;
-  config->use_compression = false;
+  config->use_compression = use_compression;
-  config->use_metadata = false;
+  config->use_metadata = use_metadata;
   config->show_progress = false;
   config->dry_run = false;
   config->use_delete = false;
-  config->compression_level = 5;
+  config->compression_level = compression_level;
-  config->use_sendfile = false;
+  config->use_sendfile = use_sendfile;
-  config->chunk_size = DEFAULT_CHUNK_SIZE;
+  config->chunk_size = chunk_size > 0 ? chunk_size : DEFAULT_CHUNK_SIZE;
   config->ssh_port = 22;
   config->transport = TRANSPORT_TCP;
   config->ssh_destination = NULL;
-  config->fastsync_server_path = NULL;
   config->exclude_patterns = NULL;
   config->exclude_count = 0;
   config->include_patterns = NULL;
@@ -44,63 +48,10 @@ Config* config_create(void) {
   config->tls_cert = NULL;
   config->tls_key = NULL;
   config->tls_ca = NULL;
-  config->server_host = str_dup("127.0.0.1");
-  config->server_port = 8080;
-  config->timeout = 30;
-  config->contimeout = 10;
-  config->quiet = false;
-  config->backup = false;
-  config->backup_dir = NULL;
-  config->stats = false;
-  config->max_depth = 0;
-  config->log_file = NULL;
-  config->queue_size = 100;
   config->follow_symlinks = false;
   config->partial = false;
-  config->copy_links = false;
+  config->server_host = str_dup("127.0.0.1");
-  config->safe_links = false;
+  config->server_port = 8080;
-  config->copy_unsafe_links = false;
-  config->preserve_hard_links = false;
-  config->preserve_acls = false;
-  config->preserve_xattrs = false;
-  config->preserve_devices = false;
-  config->preserve_sparse = false;
-  config->itemize_changes = false;
-  config->out_format = NULL;
-  config->info_level = 0;
-  config->debug_level = 0;
-  config->list_only = false;
-  config->human_readable = false;
-  config->update = false;
-  config->inplace = false;
-  config->append = false;
-  config->append_verify = false;
-  config->delete_excluded = false;
-  config->delete_after = false;
-  config->max_delete = 0;
-  config->filters = NULL;
-  config->files_from = NULL;
-  config->cvs_exclude = false;
-  config->prune_empty_dirs = false;
-  config->relative = false;
-  config->rsh_command = NULL;
-  config->rsync_path = NULL;
-  config->temp_dir = NULL;
-  config->compare_dest = NULL;
-  config->copy_dest = NULL;
-  config->link_dest = NULL;
-  config->partial_dir = NULL;
-  config->suffix = NULL;
-  config->delete_before = false;
-  config->address = NULL;
-  config->bind_address = NULL;
-  config->ipv6 = false;
-  config->ipv4 = false;
-  config->daemon = false;
-  config->daemon_config = NULL;
-  config->server_mode = false;
-  config->checksum = false;
-  config->compress_choice = NULL;
   return config;
 }
 
@@ -135,7 +86,6 @@ void config_delete(Config* config) {
   free(config->send_directory);
   free(config->receive_root_directory);
   free(config->ssh_destination);
-  free(config->fastsync_server_path);
   for (int i = 0; i < config->exclude_count; i++)
     free(config->exclude_patterns[i]);
   free(config->exclude_patterns);
@@ -145,25 +95,7 @@ void config_delete(Config* config) {
   free(config->tls_cert);
   free(config->tls_key);
   free(config->tls_ca);
-  free(config->backup_dir);
   free(config->server_host);
-  free(config->out_format);
-  free(config->files_from);
-  free(config->rsh_command);
-  free(config->rsync_path);
-  free(config->temp_dir);
-  free(config->compare_dest);
-  free(config->copy_dest);
-  free(config->link_dest);
-  free(config->partial_dir);
-  free(config->suffix);
-  free(config->address);
-  free(config->bind_address);
-  free(config->daemon_config);
-  free(config->compress_choice);
-  if (config->filters) {
-    array_list_delete(config->filters);
-  }
   free(config);
 }
 
@@ -200,60 +132,26 @@ bool config_send(int file_descriptor, const Config* config) {
     return false;
   if (!send_n_data(file_descriptor, &config->delta_max_file_size, sizeof(unsigned long long)))
     return false;
-  if (!send_int(file_descriptor, config->backup))
+  if (!send_int(file_descriptor, config->exclude_count))
     return false;
-  if (!send_str(file_descriptor, config->backup_dir ? config->backup_dir : ""))
+  for (int i = 0; i < config->exclude_count; i++) {
+    if (!send_str(file_descriptor, config->exclude_patterns[i]))
+      return false;
+  }
+  if (!send_int(file_descriptor, config->include_count))
+    return false;
+  for (int i = 0; i < config->include_count; i++) {
+    if (!send_str(file_descriptor, config->include_patterns[i]))
+      return false;
+  }
+  if (!send_n_data(file_descriptor, &config->max_size, sizeof(config->max_size)))
+    return false;
+  if (!send_n_data(file_descriptor, &config->min_size, sizeof(config->min_size)))
     return false;
   if (!send_int(file_descriptor, config->follow_symlinks))
     return false;
-  if (!send_int(file_descriptor, config->copy_links))
-    return false;
-  if (!send_int(file_descriptor, config->safe_links))
-    return false;
-  if (!send_int(file_descriptor, config->copy_unsafe_links))
-    return false;
-  if (!send_int(file_descriptor, config->preserve_hard_links))
-    return false;
-  if (!send_int(file_descriptor, config->preserve_acls))
-    return false;
-  if (!send_int(file_descriptor, config->preserve_xattrs))
-    return false;
-  if (!send_int(file_descriptor, config->preserve_devices))
-    return false;
-  if (!send_int(file_descriptor, config->preserve_sparse))
-    return false;
-  if (!send_int(file_descriptor, config->update))
-    return false;
-  if (!send_int(file_descriptor, config->inplace))
-    return false;
-  if (!send_int(file_descriptor, config->append))
-    return false;
-  if (!send_int(file_descriptor, config->append_verify))
-    return false;
-  if (!send_int(file_descriptor, config->delete_excluded))
-    return false;
-  if (!send_int(file_descriptor, config->delete_after))
-    return false;
-  if (!send_n_data(file_descriptor, &config->max_delete, sizeof(config->max_delete)))
-    return false;
-  if (!send_int(file_descriptor, config->relative))
-    return false;
-  if (!send_int(file_descriptor, config->prune_empty_dirs))
-    return false;
-  if (!send_str(file_descriptor, config->temp_dir ? config->temp_dir : ""))
-    return false;
   if (!send_int(file_descriptor, config->partial))
     return false;
-  if (!send_str(file_descriptor, config->partial_dir ? config->partial_dir : ""))
-    return false;
-  if (!send_str(file_descriptor, config->suffix ? config->suffix : ""))
-    return false;
-  if (!send_int(file_descriptor, config->delete_before))
-    return false;
-  if (!send_int(file_descriptor, config->checksum))
-    return false;
-  if (!send_str(file_descriptor, config->compress_choice ? config->compress_choice : ""))
-    return false;
   Status status;
   if (!receive_status(file_descriptor, &status))
     return false;
@@ -338,7 +236,6 @@ Config* config_receive(int file_descriptor) {
   config->ssh_port = 22;
   config->transport = TRANSPORT_TCP;
   config->ssh_destination = NULL;
-  config->fastsync_server_path = NULL;
   config->exclude_patterns = NULL;
   config->exclude_count = 0;
   config->include_patterns = NULL;
@@ -349,139 +246,90 @@ Config* config_receive(int file_descriptor) {
   config->tls_cert = NULL;
   config->tls_key = NULL;
   config->tls_ca = NULL;
-  config->timeout = 30;
-  config->contimeout = 10;
-  config->quiet = false;
-  config->stats = false;
-  config->max_depth = 0;
-  config->log_file = NULL;
-  config->queue_size = 100;
   config->follow_symlinks = false;
-  config->copy_links = false;
+  config->partial = false;
-  config->safe_links = false;
+
-  config->copy_unsafe_links = false;
+#define MAX_PATTERN_COUNT 10000
-  config->preserve_hard_links = false;
+
-  config->preserve_acls = false;
+  // Receive exclude patterns
-  config->preserve_xattrs = false;
+  int ec;
-  config->preserve_devices = false;
+  if (!receive_int(file_descriptor, &ec))
-  config->preserve_sparse = false;
-  config->itemize_changes = false;
-  config->out_format = NULL;
-  config->info_level = 0;
-  config->debug_level = 0;
-  config->list_only = false;
-  config->human_readable = false;
-  config->update = false;
-  config->inplace = false;
-  config->append = false;
-  config->append_verify = false;
-  config->delete_excluded = false;
-  config->delete_after = false;
-  config->max_delete = 0;
-  config->filters = NULL;
-  config->files_from = NULL;
-  config->cvs_exclude = false;
-  config->prune_empty_dirs = false;
-  config->relative = false;
-  config->rsh_command = NULL;
-  config->rsync_path = NULL;
-  config->temp_dir = NULL;
-  config->compare_dest = NULL;
-  config->copy_dest = NULL;
-  config->link_dest = NULL;
-  if (!receive_int(file_descriptor, &tmp))
     goto error;
-  config->backup = tmp;
+  if (ec > MAX_PATTERN_COUNT) {
-  config->backup_dir = receive_str(file_descriptor);
+    log_message(LOG_LEVEL_ERROR, "Exclude pattern count %d exceeds maximum %d", ec,
-  if (config->backup_dir == NULL)
+                MAX_PATTERN_COUNT);
-    goto error;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->follow_symlinks = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->copy_links = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->safe_links = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->copy_unsafe_links = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->preserve_hard_links = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->preserve_acls = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->preserve_xattrs = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->preserve_devices = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->preserve_sparse = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->update = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->inplace = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->append = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->append_verify = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->delete_excluded = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->delete_after = tmp;
-  if (!receive_n_data(file_descriptor, &config->max_delete, sizeof(config->max_delete)))
-    goto error;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->relative = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->prune_empty_dirs = tmp;
-  config->temp_dir = receive_str(file_descriptor);
-  if (config->temp_dir == NULL)
-    goto error;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->partial = tmp;
-  config->partial_dir = receive_str(file_descriptor);
-  if (config->partial_dir == NULL)
-    goto error;
-  config->suffix = receive_str(file_descriptor);
-  if (config->suffix == NULL)
-    goto error;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->delete_before = tmp;
-  if (!receive_int(file_descriptor, &tmp))
-    goto error;
-  config->checksum = tmp;
-  config->compress_choice = receive_str(file_descriptor);
-  if (config->compress_choice == NULL)
-    goto error;
-  if (config->compress_choice[0] != '\0' && strcmp(config->compress_choice, "zstd") != 0 &&
-      strcmp(config->compress_choice, "none") != 0) {
-    fprintf(stderr, "Unsupported compression choice: %s\n", config->compress_choice);
-    send_status(file_descriptor, STATUS_ERROR);
     goto error;
   }
-  config->address = NULL;
+  if ((size_t)ec > SIZE_MAX / sizeof(char*)) {
-  config->bind_address = NULL;
+    log_message(LOG_LEVEL_ERROR, "Exclude pattern count %d would cause integer overflow", ec);
-  config->ipv6 = false;
+    goto error;
-  config->ipv4 = false;
+  }
-  config->daemon = false;
+  config->exclude_count = ec;
-  config->daemon_config = NULL;
+  if (ec > 0) {
-  config->server_mode = false;
+    config->exclude_patterns = malloc((size_t)ec * sizeof(char*));
+    if (!config->exclude_patterns) {
+      config->exclude_count = 0;
+      goto error;
+    }
+    for (int i = 0; i < ec; i++) {
+      config->exclude_patterns[i] = receive_str(file_descriptor);
+      if (!config->exclude_patterns[i]) {
+        for (int j = 0; j < i; j++)
+          free(config->exclude_patterns[j]);
+        free(config->exclude_patterns);
+        config->exclude_patterns = NULL;
+        config->exclude_count = 0;
+        goto error;
+      }
+    }
+  }
+
+  // Receive include patterns
+  int ic;
+  if (!receive_int(file_descriptor, &ic))
+    goto error;
+  if (ic > MAX_PATTERN_COUNT) {
+    log_message(LOG_LEVEL_ERROR, "Include pattern count %d exceeds maximum %d", ic,
+                MAX_PATTERN_COUNT);
+    goto error;
+  }
+  if ((size_t)ic > SIZE_MAX / sizeof(char*)) {
+    log_message(LOG_LEVEL_ERROR, "Include pattern count %d would cause integer overflow", ic);
+    goto error;
+  }
+  config->include_count = ic;
+  if (ic > 0) {
+    config->include_patterns = malloc((size_t)ic * sizeof(char*));
+    if (!config->include_patterns) {
+      config->include_count = 0;
+      goto error;
+    }
+    for (int i = 0; i < ic; i++) {
+      config->include_patterns[i] = receive_str(file_descriptor);
+      if (!config->include_patterns[i]) {
+        for (int j = 0; j < i; j++)
+          free(config->include_patterns[j]);
+        free(config->include_patterns);
+        config->include_patterns = NULL;
+        config->include_count = 0;
+        goto error;
+      }
+    }
+  }
+
+  if (!receive_n_data(file_descriptor, &config->max_size, sizeof(config->max_size)))
+    goto error;
+  if (!receive_n_data(file_descriptor, &config->min_size, sizeof(config->min_size)))
+    goto error;
+  int tmp_follow;
+  if (!receive_int(file_descriptor, &tmp_follow))
+    goto error;
+  config->follow_symlinks = tmp_follow;
+  int tmp_partial;
+  if (!receive_int(file_descriptor, &tmp_partial))
+    goto error;
+  config->partial = tmp_partial;
+
   config->server_host = str_dup("127.0.0.1");
   config->server_port = 8080;
   if (!send_status(file_descriptor, STATUS_OK))
@@ -493,11 +341,6 @@ error:
   free(config->send_directory);
   free(config->receive_root_directory);
   free(config->server_host);
-  free(config->backup_dir);
-  free(config->temp_dir);
-  free(config->partial_dir);
-  free(config->suffix);
-  free(config->compress_choice);
   free(config);
   return NULL;
 }

src/shared/config.h

@@ -1,10 +1,8 @@
 #ifndef CONFIG_H
 #define CONFIG_H
 
-#include "array_list.h"
 #include <stdbool.h>
 #include <stdint.h>
-#include <stdio.h>
 
 typedef enum { TRANSPORT_TCP, TRANSPORT_SSH } TransportType;
 
@@ -26,7 +24,6 @@ typedef struct Config {
   int ssh_port;
   TransportType transport;
   char* ssh_destination;
-  char* fastsync_server_path;
   char** exclude_patterns;
   int exclude_count;
   char** include_patterns;
@@ -43,95 +40,17 @@ typedef struct Config {
   char* tls_cert;
   char* tls_key;
   char* tls_ca;
-  int timeout;
-  int contimeout;
-  bool quiet;
-  bool backup;
-  char* backup_dir;
-  bool stats;
-  int max_depth;
-  FILE* log_file;
-  int queue_size;
   bool follow_symlinks;
   bool partial;
-
-  // Issue #120: Symlink handling
-  bool copy_links;
-  bool safe_links;
-  bool copy_unsafe_links;
-
-  // Issue #121: Extended metadata preservation
-  bool preserve_hard_links;
-  bool preserve_acls;
-  bool preserve_xattrs;
-  bool preserve_devices;
-  bool preserve_sparse;
-
-  // Issue #122: Output/logging options
-  bool itemize_changes;
-  char* out_format;
-  int info_level;
-  int debug_level;
-  bool list_only;
-  bool human_readable;
-
-  // Issue #127: Transfer modes
-  bool update;
-  bool inplace;
-  bool append;
-  bool append_verify;
-
-  // Issue #128: Extended delete options
-  bool delete_excluded;
-  bool delete_after;
-  int max_delete;
-
-  // Issue #129: Advanced file selection
-  ArrayList* filters;
-  char* files_from;
-  bool cvs_exclude;
-  bool prune_empty_dirs;
-  bool relative;
-
-  // Issue #130: Remote shell/connection options
-  char* rsh_command;
-  char* rsync_path;
-  char* temp_dir;
-  char* compare_dest;
-  char* copy_dest;
-  char* link_dest;
-
-  // PR #174: Partial transfer resumption
-  char* partial_dir;
-
-  // PR #178: Backup versioning
-  char* suffix;
-
-  // PR #179: Delete policies
-  bool delete_before;
-
-  // PR #181: IPv6 and bind address
-  char* address;
-  char* bind_address;
-  bool ipv6;
-  bool ipv4;
-
-  // PR #182: Daemon/server mode
-  bool daemon;
-  char* daemon_config;
-  bool server_mode;
-
-  // PR #183: Checksum comparison
-  bool checksum;
-
-  // PR #184: Compression algorithm negotiation
-  char* compress_choice;
 } Config;
 
-#define PROTOCOL_VERSION "2.2.0"
+#define PROTOCOL_VERSION "1.3.0"
 #define DEFAULT_CHUNK_SIZE (10 * 1024 * 1024)
 
-Config* config_create(void);
+Config* config_create(char* version, char* send_directory, char* receive_directory,
+                      bool save_to_disk, bool use_multithreading, bool use_chunk_serialization,
+                      bool use_compression, bool use_metadata, int compression_level,
+                      bool use_sendfile, unsigned long long chunk_size);
 void config_delete(Config* config);
 bool config_send(int file_descriptor, const Config* config);
 Config* config_receive(int file_descriptor);

src/shared/data.c

@@ -1,6 +1,6 @@
 #include "data.h"
 #include "log.h"
-#include <stdlib.h>
+#include "stdlib.h"
 
 Data* data_create_empty(size_t data_size) {
   /* malloc(0) is UB; allocate at least 1 byte but preserve requested size */

src/shared/delta.c

@@ -1,6 +1,5 @@
 #include "delta.h"
 #include "log.h"
-#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -8,10 +7,6 @@
 #define XXH_IMPLEMENTATION
 #include <xxhash.h>
 
-/* Maximum number of blocks/instructions allowed from the wire to prevent OOM */
-#define MAX_DELTA_BLOCKS (1024U * 1024U)       /* 1M signature blocks */
-#define MAX_DELTA_INSTRUCTIONS (1024U * 1024U) /* 1M delta instructions */
-
 uint32_t delta_adler32(const void* data, uint32_t len) {
   const uint8_t* p = (const uint8_t*)data;
   uint32_t s1 = 1;
@@ -27,10 +22,6 @@ uint32_t delta_xxhash32(const void* data, uint32_t len) {
   return XXH32(data, len, 0);
 }
 
-uint64_t delta_xxhash64(const void* data, size_t len) {
-  return XXH64(data, len, 0);
-}
-
 DeltaSignature* delta_signature_create(const void* old_file_data, uint64_t old_file_size,
                                        uint32_t block_size) {
   if (old_file_data == NULL || old_file_size == 0 || block_size == 0)
@@ -110,14 +101,6 @@ DeltaSignature* delta_signature_deserialize(const Data* data) {
   memcpy(&sig->block_count, buf + pos, sizeof(uint32_t));
   pos += sizeof(uint32_t);
 
-  // Reject unreasonably large block counts to prevent OOM
-  if (sig->block_count > MAX_DELTA_BLOCKS) {
-    log_message(LOG_LEVEL_ERROR, "Delta signature block count %u exceeds maximum %u",
-                sig->block_count, MAX_DELTA_BLOCKS);
-    free(sig);
-    return NULL;
-  }
-
   uint64_t expected = sizeof(uint64_t) + sizeof(uint32_t) + sizeof(uint32_t) +
                       (uint64_t)sig->block_count * (sizeof(uint32_t) + sizeof(uint32_t));
   if (data->size < expected) {
@@ -125,12 +108,7 @@ DeltaSignature* delta_signature_deserialize(const Data* data) {
     return NULL;
   }
 
-  uint64_t blocks_size = (uint64_t)sig->block_count * sizeof(DeltaBlockSig);
+  sig->blocks = malloc(sig->block_count * sizeof(DeltaBlockSig));
-  if (blocks_size > SIZE_MAX) {
-    free(sig);
-    return NULL;
-  }
-  sig->blocks = malloc((size_t)blocks_size);
   if (!sig->blocks) {
     free(sig);
     return NULL;
@@ -357,14 +335,6 @@ Delta* delta_deserialize(const Data* data) {
   memcpy(&delta->instruction_count, buf + pos, sizeof(uint32_t));
   pos += sizeof(uint32_t);
 
-  // Reject unreasonably large instruction counts to prevent OOM
-  if (delta->instruction_count > MAX_DELTA_INSTRUCTIONS) {
-    log_message(LOG_LEVEL_ERROR, "Delta instruction count %u exceeds maximum %u",
-                delta->instruction_count, MAX_DELTA_INSTRUCTIONS);
-    free(delta);
-    return NULL;
-  }
-
   delta->instructions = malloc(delta->instruction_count * sizeof(DeltaInstruction));
   if (!delta->instructions) {
     free(delta);

src/shared/delta.h

@@ -72,6 +72,5 @@ bool delta_is_worthwhile(const Delta* delta, uint64_t new_file_size);
 
 uint32_t delta_adler32(const void* data, uint32_t len);
 uint32_t delta_xxhash32(const void* data, uint32_t len);
-uint64_t delta_xxhash64(const void* data, size_t len);
 
 #endif

src/shared/file.c

@@ -2,7 +2,6 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <libgen.h>
-#include <limits.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -22,18 +21,8 @@
 #include "protocol.h"
 #include "utils.h"
 
-bool file_checksum(File* file, uint64_t* checksum) {
+#define STREAM_THRESHOLD (64ULL * 1024 * 1024) /* 64 MB */
-  if (!file || !checksum || !file->data)
+#define STREAM_CHUNK_SIZE (1ULL * 1024 * 1024) /* 1 MB */
-    return false;
-  if (file->data->size == 0) {
-    *checksum = delta_xxhash64("", 0);
-    return true;
-  }
-  if (!file->data->data && !file_load_data(file))
-    return false;
-  *checksum = delta_xxhash64(file->data->data, file->data->size);
-  return true;
-}
 
 File* file_create(const char* path) {
   File* file = (File*)malloc(sizeof(File));
@@ -49,8 +38,7 @@ File* file_create(const char* path) {
     return NULL;
   }
 
-  memcpy(file->path, path, path_len);
+  memcpy(file->path, path, path_len + 1);
-  file->path[path_len] = '\0';
   file->data = data_create_reserve(0);
   if (file->data == NULL) {
     free(file->path);
@@ -58,7 +46,8 @@ File* file_create(const char* path) {
     return NULL;
   }
   file->metadata = NULL;
-  file->skip = false;
+  file->type = FILE_TYPE_REGULAR;
+  file->link_target = NULL;
   return file;
 }
 
@@ -72,6 +61,8 @@ void file_destroy(void* item) {
   file->metadata = NULL;
   free(file->path);
   file->path = NULL;
+  free(file->link_target);
+  file->link_target = NULL;
   free(file);
 }
 
@@ -100,6 +91,14 @@ void file_metadata_destroy(void* metadata) {
 bool file_load_data(File* file) {
   if (file == NULL)
     return false;
+  // Symlinks have no data to load
+  if (file->type == FILE_TYPE_SYMLINK)
+    return true;
+  // For streaming files, just record the size, don't load into memory
+  if (file->data->size > STREAM_THRESHOLD) {
+    // Don't allocate; streaming will read directly from disk
+    return true;
+  }
   if (file->data->data == NULL) {
     file->data->data = malloc(file->data->size);
     if (file->data->data == NULL) {
@@ -115,11 +114,77 @@ bool file_load_data(File* file) {
   return true;
 }
 
+// Stream file content in chunks without loading entire file into RAM
+static bool file_send_streaming(File* file, int file_descriptor) {
+  unsigned long long total_size = file->data->size;
+  // Send total size prefix (same wire format as send_data)
+  if (!send_n_data(file_descriptor, &total_size, sizeof(total_size)))
+    return false;
+
+  FILE* fp = fopen(file->path, "rb");
+  if (!fp) {
+    perror("Could not open file for streaming");
+    return false;
+  }
+
+  char* buf = malloc(STREAM_CHUNK_SIZE);
+  if (!buf) {
+    fclose(fp);
+    return false;
+  }
+  unsigned long long remaining = total_size;
+  while (remaining > 0) {
+    size_t to_read = (size_t)((remaining < STREAM_CHUNK_SIZE) ? remaining : STREAM_CHUNK_SIZE);
+    size_t nread = fread(buf, 1, to_read, fp);
+    if (nread != to_read) {
+      if (ferror(fp)) {
+        perror("Read error during streaming");
+      }
+      free(buf);
+      fclose(fp);
+      return false;
+    }
+    if (!send_n_data(file_descriptor, buf, nread)) {
+      free(buf);
+      fclose(fp);
+      return false;
+    }
+    remaining -= (unsigned long long)nread;
+  }
+  free(buf);
+  fclose(fp);
+  return true;
+}
+
 bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
                             int compression_level, bool send_path) {
+  if (send_path && !send_str(file_descriptor, file->path))
+    return false;
+  if (use_metadata && !metadata_send(file_descriptor, file->metadata))
+    return false;
+
+  // Send file type indicator so receiver can distinguish regular from symlink
+  int ft = (int)file->type;
+  if (!send_int(file_descriptor, ft))
+    return false;
+
+  if (file->type == FILE_TYPE_SYMLINK) {
+    // Send link target, then zero-length data
+    if (!send_str(file_descriptor, file->link_target ? file->link_target : ""))
+      return false;
+    Data empty = {NULL, 0};
+    return send_data(file_descriptor, &empty);
+  }
+
   const Data* data_to_send = file->data;
   Data* compressed_data = NULL;
-  if (compression_level > 0 && !compression_should_skip(file->path)) {
+
+  // Streaming mode: for large files without compression, stream from disk
+  if (file->data->size > STREAM_THRESHOLD && compression_level == 0) {
+    return file_send_streaming(file, file_descriptor);
+  }
+
+  if (compression_level > 0) {
     compressed_data = data_compress(file->data, compression_level);
     if (compressed_data == NULL) {
       log_message(LOG_LEVEL_ERROR, "Failed to compress file data");
@@ -127,14 +192,6 @@ bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
     }
     data_to_send = compressed_data;
   }
-  if (send_path && !send_str(file_descriptor, file->path)) {
-    data_destroy(compressed_data);
-    return false;
-  }
-  if (use_metadata && !metadata_send(file_descriptor, file->metadata)) {
-    data_destroy(compressed_data);
-    return false;
-  }
   if (!send_data(file_descriptor, data_to_send)) {
     data_destroy(compressed_data);
     return false;
@@ -143,122 +200,54 @@ bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
   return true;
 }
 
-bool file_save_to_disk(const char* root_directory, File* file, const Config* config) {
+static bool has_path_traversal(const char* path) {
-  bool backup_enabled = config && config->backup;
+  // Check if ".." appears as a path component — at start, end, or between '/'
-  bool inplace = config && config->inplace;
+  const char* p = path;
-  bool sparse = config && config->preserve_sparse;
+  while ((p = strstr(p, "..")) != NULL) {
-  const char* backup_suffix = (config && config->suffix) ? config->suffix : "~";
+    bool at_start = (p == path);
-  const char* backup_dir = (config && config->backup_dir) ? config->backup_dir : NULL;
+    bool after_slash = (p > path && p[-1] == '/');
-  const char* partial_dir = (config && config->partial_dir) ? config->partial_dir : NULL;
+    bool at_end = (p[2] == '\0');
-
+    bool before_slash = (p[2] == '/');
-  if (has_path_traversal(file->path)) {
+    if ((at_start || after_slash) && (at_end || before_slash))
-    log_message(LOG_LEVEL_ERROR, "Path traversal detected in file path: %s", file->path);
-    return false;
-  }
-
-  char* resolved_root = NULL;
-  const char* actual_root =
-      (partial_dir && config && config->partial) ? partial_dir : root_directory;
-  resolved_root = realpath(actual_root, NULL);
-  if (resolved_root == NULL) {
-    if (mkdir_r(actual_root)) {
-      resolved_root = realpath(actual_root, NULL);
-    }
-  }
-  if (resolved_root == NULL) {
-    log_message(LOG_LEVEL_ERROR, "Failed to resolve destination root: %s", actual_root);
-    return false;
-  }
-
-  char* disk_path = path_cat(resolved_root, file->path);
-  if (disk_path == NULL) {
-    free(resolved_root);
-    return false;
-  }
-
-  /* --update is receiver-side policy: never replace a newer destination. */
-  if (config && config->update) {
-    struct stat destination_stat;
-    if (stat(disk_path, &destination_stat) == 0 && file->metadata &&
-        destination_stat.st_mtime > file->metadata->mtime_sec) {
-      free(resolved_root);
-      free(disk_path);
       return true;
+    p += 2;
+  }
+  return false;
+}
+
+bool file_save_to_disk(const char* root_directory, File* file) {
+  if (file->type == FILE_TYPE_SYMLINK && file->link_target) {
+    // Validate link_target — reject absolute paths or traversal
+    if (file->link_target[0] == '/' || has_path_traversal(file->link_target)) {
+      log_message(LOG_LEVEL_ERROR, "Path traversal blocked in symlink target: %s",
+                  file->link_target);
+      return false;
     }
-  }
+    char* disk_path = path_cat((char*)root_directory, file->path);
-
+    if (disk_path == NULL)
-  if (backup_enabled) {
+      return false;
-    struct stat backup_stat;
+    if (has_path_traversal(disk_path)) {
-    if (stat(disk_path, &backup_stat) == 0) {
+      log_message(LOG_LEVEL_ERROR, "Path traversal blocked: %s", disk_path);
-      char* backup_path = NULL;
+      free(disk_path);
-      if (backup_dir) {
+      return false;
-        char* resolved_backup_dir = realpath(backup_dir, NULL);
-        if (!resolved_backup_dir) {
-          mkdir_r(backup_dir);
-          resolved_backup_dir = realpath(backup_dir, NULL);
-        }
-        if (resolved_backup_dir) {
-          backup_path = path_cat(resolved_backup_dir, file->path);
-          free(resolved_backup_dir);
-        }
-      }
-      if (!backup_path) {
-        size_t path_len = strlen(disk_path);
-        size_t suffix_len = strlen(backup_suffix);
-        backup_path = malloc(path_len + suffix_len + 1);
-        if (backup_path) {
-          memcpy(backup_path, disk_path, path_len);
-          memcpy(backup_path + path_len, backup_suffix, suffix_len + 1);
-        }
-      }
-      if (backup_path) {
-        char* backup_dir_path = str_dup(backup_path);
-        if (backup_dir_path) {
-          const char* bdir = dirname(backup_dir_path);
-          mkdir_r(bdir);
-          free(backup_dir_path);
-        }
-        rename(disk_path, backup_path);
-        free(backup_path);
-      }
     }
+    unlink(disk_path);
+    bool ok = (symlink(file->link_target, disk_path) == 0);
+    if (ok && file->metadata)
+      file_restore_metadata(disk_path, file->metadata);
+    free(disk_path);
+    return ok;
   }
 
-  char* dir_dup = str_dup(disk_path);
+  char* disk_path = path_cat((char*)root_directory, file->path);
-  if (!dir_dup) {
+  if (disk_path == NULL)
-    free(resolved_root);
+    return false;
+  if (has_path_traversal(disk_path)) {
+    log_message(LOG_LEVEL_ERROR, "Path traversal blocked: %s", disk_path);
     free(disk_path);
     return false;
   }
-  char* dir_str = dirname(dir_dup);
+  bool ok = to_disk(disk_path, file->data->data, file->data->size);
-  if (!mkdir_r(dir_str)) {
-    free(dir_dup);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-  char* resolved_dir = realpath(dir_str, NULL);
-  free(dir_dup);
-  if (resolved_dir == NULL) {
-    log_message(LOG_LEVEL_ERROR, "Failed to resolve directory for: %s", disk_path);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-
-  size_t root_len = strlen(resolved_root);
-  if (strncmp(resolved_dir, resolved_root, root_len) != 0 ||
-      (resolved_dir[root_len] != '\0' && resolved_dir[root_len] != '/')) {
-    log_message(LOG_LEVEL_ERROR, "Path escape detected: %s is outside %s", disk_path, actual_root);
-    free(resolved_dir);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-  free(resolved_dir);
-  free(resolved_root);
-
-  bool ok = to_disk(disk_path, file->data->data, file->data->size, inplace, sparse);
   if (ok)
     file_restore_metadata(disk_path, file->metadata);
   free(disk_path);
@@ -283,6 +272,43 @@ static void* old_data_from_path(const char* full_path, unsigned long long old_si
   return data;
 }
 
+/**
+ * Helper: receive data from wire, optionally decompress, and store in file.
+ * On success, returns the received Data* (caller owns it). On failure, returns NULL.
+ * If `file_data` is received via receive_data(fd), this function handles decompression
+ * when config->use_compression is set.
+ */
+static Data* receive_and_decompress(int fd, const Config* config) {
+  Data* file_data = receive_data(fd);
+  if (file_data == NULL)
+    return NULL;
+  if (config->use_compression) {
+    Data* uncompressed = data_decompress(file_data);
+    data_destroy(file_data);
+    if (uncompressed == NULL)
+      return NULL;
+    file_data = uncompressed;
+  }
+  return file_data;
+}
+
+/**
+ * Helper: receive metadata from wire and assign to file.
+ * Returns true on success (metadata may be NULL if absent), false on I/O error.
+ */
+static bool receive_and_assign_metadata(int fd, const Config* config, File* file) {
+  if (!config->use_metadata)
+    return true;
+  int meta_ok = 1;
+  file->metadata = metadata_receive(fd, &meta_ok);
+  if (!meta_ok) {
+    file_destroy(file);
+    send_status(fd, STATUS_ERROR);
+    return false;
+  }
+  return true;
+}
+
 static File* receive_delta_file(int fd, const Config* config, const char* check_path,
                                 void* old_data, unsigned long long old_size) {
   if (!old_data)
@@ -398,34 +424,16 @@ static File* receive_delta_file(int fd, const Config* config, const char* check_
       return NULL;
     }
 
-    if (config->use_metadata) {
+    if (!receive_and_assign_metadata(fd, config, file))
-      int meta_ok = 1;
+      return NULL;
-      file->metadata = metadata_receive(fd, &meta_ok);
-      if (!meta_ok) {
-        file_destroy(file);
-        send_status(fd, STATUS_ERROR);
-        return NULL;
-      }
-    }
 
-    Data* file_data = receive_data(fd);
+    Data* file_data = receive_and_decompress(fd, config);
     if (file_data == NULL) {
       file_destroy(file);
       send_status(fd, STATUS_ERROR);
       return NULL;
     }
 
-    if (config->use_compression) {
-      Data* uncompressed = data_decompress(file_data);
-      data_destroy(file_data);
-      if (uncompressed == NULL) {
-        file_destroy(file);
-        send_status(fd, STATUS_ERROR);
-        return NULL;
-      }
-      file_data = uncompressed;
-    }
-
     data_destroy(file->data);
     file->data = file_data;
     return file;
@@ -446,43 +454,40 @@ File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
 
   unsigned long long check_size;
   long long check_mtime;
-  uint64_t check_checksum = 0;
   if (!receive_n_data(fd, &check_size, sizeof(check_size)) ||
       !receive_n_data(fd, &check_mtime, sizeof(check_mtime))) {
     free(check_path);
     send_status(fd, STATUS_ERROR);
     return NULL;
   }
-  if (config->checksum && !receive_n_data(fd, &check_checksum, sizeof(check_checksum))) {
-    free(check_path);
-    send_status(fd, STATUS_ERROR);
-    return NULL;
-  }
-
-  if (has_path_traversal(check_path)) {
-    log_message(LOG_LEVEL_ERROR, "Path traversal detected: %s", check_path);
-    free(check_path);
-    send_status(fd, STATUS_ERROR);
-    return NULL;
-  }
 
   char* full_path = path_cat(config->receive_root_directory, check_path);
+  if (full_path && strstr(full_path, "..") != NULL) {
+    log_message(LOG_LEVEL_ERROR, "Path traversal blocked: %s", full_path);
+    free(full_path);
+    free(check_path);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
   struct stat st;
-  bool has_old_file = (full_path && lstat(full_path, &st) == 0);
+  bool has_old_file = (full_path && stat(full_path, &st) == 0);
   unsigned long long old_size = has_old_file ? (unsigned long long)st.st_size : 0;
 
-  bool match = has_old_file && (unsigned long long)st.st_size == check_size;
+  // Check for partial file if enabled
-  if (match && config->checksum) {
+  if (config->partial && !has_old_file && full_path) {
-    void* old_data = old_size > 0 ? old_data_from_path(full_path, old_size) : NULL;
+    char* partial_path = malloc(strlen(full_path) + 20);
-    uint64_t old_checksum = old_size == 0 ? delta_xxhash64("", 0) : 0;
+    if (partial_path) {
-    if (old_data)
+      snprintf(partial_path, strlen(full_path) + 20, "%s.fastsync-partial", full_path);
-      old_checksum = delta_xxhash64(old_data, (size_t)old_size);
+      has_old_file = (stat(partial_path, &st) == 0);
-    match = (old_size == 0 || old_data) && old_checksum == check_checksum;
+      if (has_old_file)
-    free(old_data);
+        old_size = (unsigned long long)st.st_size;
-  } else if (match) {
+      free(partial_path);
-    match = (long long)st.st_mtime == check_mtime;
+    }
   }
 
+  bool match = has_old_file && (unsigned long long)st.st_size == check_size &&
+               (long long)st.st_mtime == check_mtime;
+
   if (match) {
     if (!send_status(fd, STATUS_OK)) {
       free(full_path);
@@ -525,32 +530,34 @@ File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
     return NULL;
   }
 
-  if (config->use_metadata) {
+  if (!receive_and_assign_metadata(fd, config, file))
-    int meta_ok = 1;
+    return NULL;
-    file->metadata = metadata_receive(fd, &meta_ok);
-    if (!meta_ok) {
-      file_destroy(file);
-      send_status(fd, STATUS_ERROR);
-      return NULL;
-    }
-  }
 
-  Data* file_data = receive_data(fd);
+  // Read file type indicator
-  if (file_data == NULL) {
+  int file_type;
+  if (!receive_int(fd, &file_type)) {
     file_destroy(file);
     send_status(fd, STATUS_ERROR);
     return NULL;
   }
+  file->type = (FileType)file_type;
 
-  if (config->use_compression) {
+  if (file->type == FILE_TYPE_SYMLINK) {
-    Data* uncompressed = data_decompress(file_data);
+    char* link_target = receive_str(fd);
-    data_destroy(file_data);
+    if (link_target) {
-    if (uncompressed == NULL) {
+      file->link_target = link_target;
-      file_destroy(file);
-      send_status(fd, STATUS_ERROR);
-      return NULL;
     }
-    file_data = uncompressed;
+    Data* empty_data = receive_data(fd);
+    if (empty_data)
+      data_destroy(empty_data);
+    return file;
+  }
+
+  Data* file_data = receive_and_decompress(fd, config);
+  if (file_data == NULL) {
+    file_destroy(file);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
   }
 
   data_destroy(file->data);
@@ -558,211 +565,52 @@ File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
   return file;
 }
 
-static int open_secure_parent(const char* path, char** leaf_out) {
+bool to_disk(const char* path, const void* data, unsigned long long data_size) {
-  char* copy = str_dup(path);
+  // dirname() may modify its argument and may return a pointer to static storage.
-  if (!copy)
+  // We must use a copy of the result to be safe.
-    return -1;
-  char* parent = dirname(copy);
-  const char* slash = strrchr(path, '/');
-  char* leaf = str_dup(slash ? slash + 1 : path);
-  if (!leaf) {
-    free(copy);
-    return -1;
-  }
-  int fd = (parent[0] == '/') ? open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)
-                              : open(".", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
-  if (fd < 0) {
-    free(copy);
-    free(leaf);
-    return -1;
-  }
-  char* save = NULL;
-  char* component = strtok_r(parent, "/", &save);
-  while (component) {
-    if (strcmp(component, ".") != 0 && strcmp(component, "..") != 0) {
-      int next = openat(fd, component, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
-      if (next < 0 && errno == ENOENT && mkdirat(fd, component, 0755) == 0)
-        next = openat(fd, component, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
-      if (next < 0) {
-        close(fd);
-        free(copy);
-        free(leaf);
-        return -1;
-      }
-      close(fd);
-      fd = next;
-    }
-    component = strtok_r(NULL, "/", &save);
-  }
-  free(copy);
-  *leaf_out = leaf;
-  return fd;
-}
-
-static bool write_all(int fd, const void* data, unsigned long long size) {
-  const unsigned char* p = data;
-  unsigned long long done = 0;
-  while (done < size) {
-    ssize_t n = write(fd, p + done, (size_t)(size - done));
-    if (n < 0 && errno == EINTR)
-      continue;
-    if (n <= 0)
-      return false;
-    done += (unsigned long long)n;
-  }
-  return true;
-}
-
-static bool to_disk_secure(const char* path, const void* data, unsigned long long data_size,
-                           bool inplace, bool sparse) {
-  char* leaf = NULL;
-  int dirfd = open_secure_parent(path, &leaf);
-  if (dirfd < 0)
-    return false;
-  int fd = -1;
-  bool ok = false;
-  if (inplace) {
-    fd = openat(dirfd, leaf, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW, 0644);
-    if (fd >= 0) {
-      if (!sparse || data_size == 0 || ftruncate(fd, (off_t)data_size) == 0)
-        ok = write_all(fd, data, data_size);
-    }
-  } else {
-    char tmp[NAME_MAX];
-    for (unsigned int i = 0; i < 100 && !ok; ++i) {
-      snprintf(tmp, sizeof(tmp), ".%s.tmp.%ld.%u", leaf, (long)getpid(), i);
-      fd = openat(dirfd, tmp, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC | O_NOFOLLOW, 0600);
-      if (fd < 0)
-        continue;
-      if (sparse && data_size > 0)
-        ok = ftruncate(fd, (off_t)data_size) == 0;
-      if (ok || (!sparse || data_size == 0))
-        ok = write_all(fd, data, data_size);
-      if (close(fd) != 0)
-        ok = false;
-      fd = -1;
-      if (ok && renameat(dirfd, tmp, dirfd, leaf) != 0)
-        ok = false;
-      if (!ok)
-        unlinkat(dirfd, tmp, 0);
-    }
-  }
-  if (fd >= 0)
-    close(fd);
-  close(dirfd);
-  free(leaf);
-  return ok;
-}
-
-bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
-             bool sparse) {
-  if (!path || (!data && data_size != 0) || has_path_traversal(path))
-    return false;
-  return to_disk_secure(path, data, data_size, inplace, sparse);
-  /* Kept below only as historical context; all writes use descriptor-relative operations. */
-  char* tmp_path = NULL;
-  char* directory = NULL;
-
   char* path_dup = str_dup(path);
   if (!path_dup)
     return false;
   const char* dir_result = dirname(path_dup);
-  directory = str_dup(dir_result);
+  char* directory = str_dup(dir_result);
   free(path_dup);
   if (!directory)
     return false;
 
   bool ok = true;
-  if (!mkdir_r(directory))
+  if (!mkdir_r(directory)) {
-    goto done;
-
-  if (inplace) {
-    FILE* file_pointer = fopen(path, "wb");
-    if (file_pointer == NULL) {
-      perror("Could not open file for inplace write");
-      ok = false;
-      goto done;
-    }
-    if (sparse && data_size > 0) {
-      if (fseek(file_pointer, data_size - 1, SEEK_SET) != 0) {
-        perror("Failed to seek for sparse file");
-        fclose(file_pointer);
-        ok = false;
-        goto done;
-      }
-      if (fwrite("", 1, 1, file_pointer) != 1) {
-        perror("Failed to write sparse file");
-        fclose(file_pointer);
-        ok = false;
-        goto done;
-      }
-      rewind(file_pointer);
-    }
-    if (data_size > 0 && fwrite(data, 1, data_size, file_pointer) != data_size) {
-      perror("Failed to write all data to file");
-      fclose(file_pointer);
-      ok = false;
-      goto done;
-    }
-    fclose(file_pointer);
-    free(directory);
-    return true;
-  }
-
-  size_t path_len = strlen(path);
-  tmp_path = malloc(path_len + 5);
-  if (!tmp_path) {
     ok = false;
     goto done;
   }
-  memcpy(tmp_path, path, path_len);
+  FILE* file_pointer = fopen(path, "wb");
-  memcpy(tmp_path + path_len, ".tmp", 5);
-
-  FILE* file_pointer = fopen(tmp_path, "wb");
   if (file_pointer == NULL) {
-    perror("Could not open temporary file");
+    perror("Could not open File");
     ok = false;
     goto done;
   }
-  if (sparse && data_size > 0) {
-    if (fseek(file_pointer, data_size - 1, SEEK_SET) != 0) {
-      perror("Failed to seek for sparse file");
-      fclose(file_pointer);
-      ok = false;
-      goto done;
-    }
-    if (fwrite("", 1, 1, file_pointer) != 1) {
-      perror("Failed to write sparse file");
-      fclose(file_pointer);
-      ok = false;
-      goto done;
-    }
-    rewind(file_pointer);
-  }
   if (fwrite(data, 1, data_size, file_pointer) != data_size) {
-    perror("Failed to write all data to temporary file");
+    perror("Failed to write all data to disk");
     fclose(file_pointer);
-    unlink(tmp_path);
     ok = false;
     goto done;
   }
   fclose(file_pointer);
 
-  if (rename(tmp_path, path) != 0) {
-    perror("Failed to atomically rename temporary file");
-    unlink(tmp_path);
-    ok = false;
-    goto done;
-  }
-
 done:
-  free(tmp_path);
   free(directory);
   return ok;
 }
 
 bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int compression_level,
                         bool send_path) {
+  // Handle symlinks
+  if (file->type == FILE_TYPE_SYMLINK) {
+    return file_send_single_calls(file, file_descriptor, use_metadata, compression_level,
+                                  send_path);
+  }
+
+  // sendfile is incompatible with compression (kernel zero-copy).
+  // If compression is requested, fall back to the regular send path.
   if (compression_level > 0)
     return file_send_single_calls(file, file_descriptor, use_metadata, compression_level,
                                   send_path);
@@ -772,6 +620,11 @@ bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int
   if (use_metadata && !metadata_send(file_descriptor, file->metadata))
     return false;
 
+  // Send file type indicator
+  int ft = (int)file->type;
+  if (!send_int(file_descriptor, ft))
+    return false;
+
   int fd = open(file->path, O_RDONLY);
   if (fd == -1) {
     perror("Could not open file for sendfile");
@@ -788,7 +641,7 @@ bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int
   while ((unsigned long long)offset < file_size) {
     ssize_t sent = sendfile(file_descriptor, fd, &offset, file_size - offset);
     if (sent == -1) {
-      if (errno == EAGAIN || errno == EINTR)
+      if (errno == EINTR)
         continue;
       perror("sendfile failed");
       close(fd);
@@ -804,11 +657,6 @@ File* file_receive(const Config* config, int file_descriptor) {
   char* path = receive_str(file_descriptor);
   if (path == NULL)
     return NULL;
-  if (path[0] == '\0' || has_path_traversal(path)) {
-    log_message(LOG_LEVEL_ERROR, "Invalid received file path: %s", path);
-    free(path);
-    return NULL;
-  }
   File* file = file_create(path);
   free(path);
   if (file == NULL)
@@ -821,6 +669,30 @@ File* file_receive(const Config* config, int file_descriptor) {
       return NULL;
     }
   }
+
+  // Receive file type indicator
+  int file_type;
+  if (!receive_int(file_descriptor, &file_type)) {
+    file_destroy(file);
+    return NULL;
+  }
+  file->type = (FileType)file_type;
+
+  if (file->type == FILE_TYPE_SYMLINK) {
+    char* link_target = receive_str(file_descriptor);
+    if (link_target == NULL) {
+      file_destroy(file);
+      return NULL;
+    }
+    file->link_target = link_target;
+    // Receive and discard zero-length data
+    Data* empty_data = receive_data(file_descriptor);
+    if (empty_data)
+      data_destroy(empty_data);
+    return file;
+  }
+
+  // Regular file - receive data
   Data* file_data = receive_data(file_descriptor);
   if (file_data == NULL) {
     file_destroy(file);
@@ -835,6 +707,7 @@ File* file_receive(const Config* config, int file_descriptor) {
     }
     file_data = file_data_uncompressed;
   }
+
   data_destroy(file->data);
   file->data = file_data;
   return file;
@@ -860,22 +733,17 @@ int receive_manifest(int fd, const Config* config, int* next_status) {
   int count;
   if (!receive_int(fd, &count))
     return -1;
-  if (count < 0 || count > MAX_MANIFEST_ENTRIES)
-    return -1;
   ArrayList* manifest = array_list_create(free);
-  if (!manifest)
+  if (manifest) {
-    return -1;
+    for (int i = 0; i < count; i++) {
-  for (int i = 0; i < count; i++) {
+      char* s = receive_str(fd);
-    char* s = receive_str(fd);
+      if (s)
-    if (!s || s[0] == '\0' || has_path_traversal(s) || !array_list_add(manifest, s)) {
+        array_list_add(manifest, s);
-      free(s);
-      array_list_delete(manifest);
-      return -1;
     }
+    fprintf(stderr, "Deleting files not in manifest...\n");
+    delete_extras(config->receive_root_directory, manifest);
+    array_list_delete(manifest);
   }
-  fprintf(stderr, "Deleting files not in manifest...\n");
-  delete_extras(config->receive_root_directory, manifest);
-  array_list_delete(manifest);
   if (!receive_status(fd, next_status))
     return -1;
   return 0;

src/shared/file.h

@@ -20,13 +20,13 @@ typedef struct {
   char* path;
   Data* data;
   FileMetadata* metadata;
-  bool skip;
+  FileType type;
+  char* link_target;
 } File;
 
 File* file_create(const char* path);
 void file_destroy(void* item);
 bool file_load_data(File* file);
-bool file_checksum(File* file, uint64_t* checksum);
 File* file_receive(const Config* config, int file_descriptor);
 bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
                             int compression_level, bool send_path);
@@ -35,9 +35,8 @@ bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int
 size_t file_content_to_buffer(File* file);
 FileMetadata* file_metadata_create(const struct stat* stats);
 void file_metadata_destroy(void* metadata);
-bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
+bool to_disk(const char* path, const void* data, unsigned long long data_size);
-             bool sparse);
+bool file_save_to_disk(const char* root_directory, File* file);
-bool file_save_to_disk(const char* root_directory, File* file, const Config* config);
 File* receive_incremental_check(int fd, const Config* config, bool* skipped);
 int receive_manifest(int fd, const Config* config, int* next_status);
 

src/shared/log.c

@@ -5,16 +5,11 @@
 
 static const char* log_level_strings[] = {"DEBUG", "INFO", "WARN", "ERROR"};
 static LogLevel current_log_level = LOG_LEVEL_WARNING;
-static FILE* log_fp = NULL;
 
 void set_log_level(LogLevel level) {
   current_log_level = level;
 }
 
-void log_set_file(FILE* fp) {
-  log_fp = fp;
-}
-
 void log_message(LogLevel log_level, const char* format, ...) {
   if (log_level < current_log_level)
     return;
@@ -29,14 +24,4 @@ void log_message(LogLevel log_level, const char* format, ...) {
   vfprintf(stderr, format, args);
   va_end(args);
   fprintf(stderr, "\n");
-
-  if (log_fp) {
-    fprintf(log_fp, "%04d-%02d-%02d %02d:%02d:%02d [%s]: ", t->tm_year + 1900, t->tm_mon + 1,
-            t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, log_level_strings[log_level]);
-    va_start(args, format);
-    vfprintf(log_fp, format, args);
-    va_end(args);
-    fprintf(log_fp, "\n");
-    fflush(log_fp);
-  }
 }

src/shared/log.h

@@ -1,12 +1,9 @@
 #ifndef LOG_H
 #define LOG_H
 
-#include <stdio.h>
-
 typedef enum { LOG_LEVEL_DEBUG, LOG_LEVEL_INFO, LOG_LEVEL_WARNING, LOG_LEVEL_ERROR } LogLevel;
 
 void log_message(LogLevel log_level, const char* message, ...);
 void set_log_level(LogLevel level);
-void log_set_file(FILE* fp);
 
 #endif

src/shared/metadata.c

@@ -11,19 +11,6 @@
 #include <time.h>
 #include <unistd.h>
 
-/*
- * Wire format serialization (protocol version 2.0.0+):
- * All metadata fields are serialized as fixed-width integers (int32_t / int64_t)
- * to ensure cross-platform binary compatiblity.  See metadata.h for the
- * exact wire layout.
- *
- * Compile-time assertions verify that the native platform types fit within
- * the chosen fixed-width representations.
- */
-typedef char static_assert_mode_t_fits[(sizeof(mode_t) <= sizeof(int32_t)) ? 1 : -1];
-typedef char static_assert_uid_t_fits[(sizeof(uid_t) <= sizeof(int32_t)) ? 1 : -1];
-typedef char static_assert_gid_t_fits[(sizeof(gid_t) <= sizeof(int32_t)) ? 1 : -1];
-
 void metadata_to_buf(char** buf, const FileMetadata* m) {
   int32_t present = (m != NULL) ? 1 : 0;
   memcpy(*buf, &present, sizeof(present));
@@ -105,16 +92,11 @@ FileMetadata* metadata_receive(int file_descriptor, int* ok) {
       *ok = 0;
     return NULL;
   }
-  if (present == 0) {
+  if (!present) {
     if (ok)
       *ok = 1;
     return NULL;
   }
-  if (present != 1) {
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
   FileMetadata* m = malloc(sizeof(FileMetadata));
   if (m == NULL) {
     if (ok)
@@ -161,12 +143,6 @@ FileMetadata* metadata_receive(int file_descriptor, int* ok) {
     return NULL;
   }
   m->mtime_nsec = (long)mtime_nsec;
-  if (mtime_nsec < 0 || mtime_nsec >= 1000000000LL || mode < 0 || uid < 0 || gid < 0) {
-    free(m);
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
   if (ok)
     *ok = 1;
   return m;

src/shared/metadata.h

@@ -6,23 +6,6 @@
 #include <stdint.h>
 #include <sys/stat.h>
 
-/*
- * Wire format (introduced in protocol version 2.0.0):
- *   int32_t present
- *   int32_t mode    (was mode_t, platform-dependent)
- *   int32_t uid     (was uid_t,  platform-dependent)
- *   int32_t gid     (was gid_t,  platform-dependent)
- *   int64_t mtime_sec (was time_t, platform-dependent)
- *   int64_t mtime_nsec (was long,  platform-dependent)
- *
- * Prior to 2.0.0 the wire format used the raw platform-dependent types,
- * which broke compatiblity across different systems.  All fields are now
- * serialized as fixed-width integers.
- */
-
-/* Size of metadata fields on wire, excluding the int32_t `present` field that
- * is always sent first. The total wire size for present metadata is
- * sizeof(int32_t) + FILE_METADATA_WIRE_SIZE (32 bytes on most platforms). */
 #define FILE_METADATA_WIRE_SIZE (sizeof(int32_t) * 3 + sizeof(int64_t) * 2)
 
 void metadata_to_buf(char** buf, const FileMetadata* m);

src/shared/multiprocessing.c

@@ -24,14 +24,11 @@ PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* que
   context->scanner_done = false;
   context->loader_done = false;
   context->manifest = NULL;
-  context->progress_bytes = 0;
-  context->sender_done = false;
   if (mtx_init(&context->mutex_scanner, mtx_plain) != thrd_success ||
       cnd_init(&context->condition_not_full_scanner) != thrd_success ||
       cnd_init(&context->condition_not_empty_scanner) != thrd_success ||
       mtx_init(&context->mutex_loader, mtx_plain) != thrd_success ||
       cnd_init(&context->condition_not_full_loader) != thrd_success ||
-      mtx_init(&context->mutex_progress, mtx_plain) != thrd_success ||
       cnd_init(&context->condition_not_empty_loader) != thrd_success) {
     perror("Error initializing synchronization objects");
     free(context);
@@ -53,19 +50,17 @@ void pipeline_context_sender_destroy(PipelineContextSender* context) {
   mtx_destroy(&context->mutex_loader);
   cnd_destroy(&context->condition_not_full_loader);
   cnd_destroy(&context->condition_not_empty_loader);
-  mtx_destroy(&context->mutex_progress);
   free(context);
 }
 
 PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue* queue,
-                                                          int file_descriptor, SSL* ssl) {
+                                                          int file_descriptor) {
   PipelineContextReceiver* context = malloc(sizeof(PipelineContextReceiver));
   if (context == NULL)
     return NULL;
   context->config = config;
   context->queue = queue;
   context->file_descriptor = file_descriptor;
-  context->ssl = ssl;
   context->receiver_done = false;
   if (mtx_init(&context->mutex, mtx_plain) != thrd_success ||
       cnd_init(&context->condition_not_full) != thrd_success ||
@@ -86,10 +81,10 @@ void pipeline_context_receiver_destroy(PipelineContextReceiver* context) {
   free(context);
 }
 
-static bool receive_chunk_enqueue(int file_descriptor, PipelineContextReceiver* context) {
+static void receive_chunk_enqueue(int file_descriptor, PipelineContextReceiver* context) {
   Chunk* chunk = receive_chunk_data(file_descriptor, context->config);
   if (chunk == NULL)
-    return false;
+    return;
 
   for (int i = 0; i < chunk->element_count; i++) {
     File* file = chunk->items[i];
@@ -98,27 +93,10 @@ static bool receive_chunk_enqueue(int file_descriptor, PipelineContextReceiver*
                                 &context->condition_not_empty, &context->condition_not_full);
   }
   chunk_destroy(chunk);
-  return true;
-}
-
-static void receiver_thread_fail(PipelineContextReceiver* context) {
-  mtx_lock(&context->mutex);
-  context->cancelled = true;
-  context->receiver_done = true;
-  cnd_broadcast(&context->condition_not_empty);
-  cnd_broadcast(&context->condition_not_full);
-  mtx_unlock(&context->mutex);
 }
 
 int receive_thread(void* pipeline_context) {
-#define RECEIVE_THREAD_FAIL()                                                                      \
-  do {                                                                                             \
-    receiver_thread_fail(context);                                                                 \
-    return thrd_error;                                                                             \
-  } while (0)
   PipelineContextReceiver* context = (PipelineContextReceiver*)pipeline_context;
-  if (context->ssl)
-    io_set_ssl(context->ssl);
   mtx_lock(&context->mutex);
   int file_descriptor = context->file_descriptor;
   const Config* config = context->config;
@@ -126,56 +104,19 @@ int receive_thread(void* pipeline_context) {
 
   Status status;
   if (!receive_status(file_descriptor, &status))
-    RECEIVE_THREAD_FAIL();
+    return thrd_error;
-  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK ||
+  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK) {
-         status == STATUS_KEEPALIVE || status == STATUS_ABORT || status == STATUS_CHECK_BATCH) {
-    if (status == STATUS_KEEPALIVE) {
-      if (!send_status(file_descriptor, STATUS_KEEPALIVE))
-        RECEIVE_THREAD_FAIL();
-      goto next;
-    }
-    if (status == STATUS_ABORT) {
-      log_message(LOG_LEVEL_INFO, "Received abort from client, cleaning up");
-      RECEIVE_THREAD_FAIL();
-    }
     if (status == STATUS_CHECK) {
       bool skipped;
       File* file = receive_incremental_check(file_descriptor, config, &skipped);
       if (!skipped) {
         if (file == NULL)
-          RECEIVE_THREAD_FAIL();
+          return thrd_error;
         queue_enqueue_multithreaded(context->queue, file, &context->mutex,
                                     &context->condition_not_empty, &context->condition_not_full);
       }
     } else if (status == STATUS_CHUNK) {
-      if (!receive_chunk_enqueue(file_descriptor, context))
+      receive_chunk_enqueue(file_descriptor, context);
-        RECEIVE_THREAD_FAIL();
-    } else if (status == STATUS_CHECK_BATCH) {
-      int count;
-      if (!receive_int(file_descriptor, &count))
-        RECEIVE_THREAD_FAIL();
-      for (int i = 0; i < count; i++) {
-        char* check_path = receive_str(file_descriptor);
-        if (!check_path)
-          RECEIVE_THREAD_FAIL();
-        unsigned long long check_size;
-        long long check_mtime;
-        if (!receive_n_data(file_descriptor, &check_size, sizeof(check_size)) ||
-            !receive_n_data(file_descriptor, &check_mtime, sizeof(check_mtime))) {
-          free(check_path);
-          RECEIVE_THREAD_FAIL();
-        }
-        char* full_path = path_cat(config->receive_root_directory, check_path);
-        struct stat st;
-        bool has_old = full_path && lstat(full_path, &st) == 0;
-        bool match = has_old && (unsigned long long)st.st_size == check_size &&
-                     (long long)st.st_mtime == check_mtime;
-        if (!send_status(file_descriptor, match ? STATUS_OK : STATUS_NEXT))
-          RECEIVE_THREAD_FAIL();
-        free(full_path);
-        free(check_path);
-      }
-      goto next;
     } else {
       File* file = file_receive(config, file_descriptor);
       if (file) {
@@ -183,31 +124,24 @@ int receive_thread(void* pipeline_context) {
                                     &context->condition_not_empty, &context->condition_not_full);
       } else {
         log_message(LOG_LEVEL_ERROR, "Failed to receive file");
-        RECEIVE_THREAD_FAIL();
       }
     }
-  next:
     if (!receive_status(file_descriptor, &status))
-      RECEIVE_THREAD_FAIL();
+      return thrd_error;
   }
   if (status == STATUS_MANIFEST) {
     if (receive_manifest(file_descriptor, config, &status) != 0)
-      RECEIVE_THREAD_FAIL();
+      return thrd_error;
   }
-  if (status != STATUS_FINISHED)
-    RECEIVE_THREAD_FAIL();
   mtx_lock(&context->mutex);
   context->receiver_done = true;
   cnd_signal(&context->condition_not_empty);
   mtx_unlock(&context->mutex);
-#undef RECEIVE_THREAD_FAIL
   return thrd_success;
 }
 
 int write_thread(void* pipeline_context) {
   PipelineContextReceiver* context = (PipelineContextReceiver*)pipeline_context;
-  if (context->ssl)
-    io_set_ssl(context->ssl);
   mtx_lock(&context->mutex);
   bool save_to_disk = context->config->save_to_disk;
   char* root_directory = str_dup(context->config->receive_root_directory);
@@ -222,7 +156,7 @@ int write_thread(void* pipeline_context) {
       return thrd_success;
     }
     if (save_to_disk)
-      file_save_to_disk(root_directory, file, context->config);
+      file_save_to_disk(root_directory, file);
     file_destroy(file);
   }
 }

src/shared/multiprocessing.h

@@ -6,9 +6,7 @@
 #include "array_list.h"
 #include "config.h"
 #include "file.h"
-#include "protocol.h"
 #include "queue.h"
-#include <openssl/ssl.h>
 
 typedef struct {
   Config* config;
@@ -23,29 +21,23 @@ typedef struct {
   cnd_t condition_not_empty_loader;
   bool loader_done;
   ArrayList* manifest;
-  mtx_t mutex_progress;
-  unsigned long long progress_bytes;
-  bool sender_done;
-  bool cancelled;
 } PipelineContextSender;
 
 typedef struct PipelineContextReceiver {
   Queue* queue;
   Config* config;
   int file_descriptor;
-  SSL* ssl;
   mtx_t mutex;
   cnd_t condition_not_full;
   cnd_t condition_not_empty;
   bool receiver_done;
-  bool cancelled;
 } PipelineContextReceiver;
 
 PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* queue_scanner,
                                                       Queue* queue_loader);
 void pipeline_context_sender_destroy(PipelineContextSender* context);
 PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue* queue_receiver,
-                                                          int file_descriptor, SSL* ssl);
+                                                          int file_descriptor);
 void pipeline_context_receiver_destroy(PipelineContextReceiver* context);
 int receive_thread(void* pipeline_context);
 int write_thread(void* pipeline_context);

src/shared/protocol.c

@@ -1,29 +1,21 @@
 #include "protocol.h"
 #include "log.h"
 #include <errno.h>
-#include <limits.h>
 #include <openssl/ssl.h>
-#include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
 
-#define MAX_DATA_SIZE (100ULL * 1024 * 1024)          /* 100 MB max per data message */
-#define RECEIVE_TIMEOUT_SEC 60                        /* 60 second per-message timeout */
-#define MAX_CONNECTION_MEMORY (1024ULL * 1024 * 1024) /* 1 GB total per connection */
-
 static __thread int io_read_fd = -1;
 static __thread int io_write_fd = -1;
-static __thread SSL* io_ssl;
+static SSL* io_ssl = NULL;
 
 static unsigned long long io_bwlimit = 0;
 static long long bw_tokens = 0;
 static struct timespec bw_last_refill = {0, 0};
 
-static __thread unsigned long long total_allocated_bytes = 0;
-
 void io_set_fds(int read_fd, int write_fd) {
   io_read_fd = read_fd;
   io_write_fd = write_fd;
@@ -42,11 +34,14 @@ static void bw_throttle(size_t bytes_written) {
   struct timespec now;
   clock_gettime(CLOCK_MONOTONIC, &now);
 
-  long long elapsed_ns =
+  /* Use unsigned long long for elapsed_ns to avoid overflow in multiplication.
-      (now.tv_sec - bw_last_refill.tv_sec) * 1000000000LL + (now.tv_nsec - bw_last_refill.tv_nsec);
+   * time_t differences fit comfortably in 64-bit for any practical runtime. */
+  unsigned long long elapsed_ns =
+      (unsigned long long)(now.tv_sec - bw_last_refill.tv_sec) * 1000000000ULL +
+      (unsigned long long)(now.tv_nsec - bw_last_refill.tv_nsec);
   bw_last_refill = now;
 
-  long long tokens_to_add = (long long)((double)io_bwlimit * elapsed_ns / 1000000000.0);
+  long long tokens_to_add = (long long)((double)io_bwlimit * (double)elapsed_ns / 1000000000.0);
   bw_tokens += tokens_to_add;
   if (bw_tokens > (long long)io_bwlimit)
     bw_tokens = (long long)io_bwlimit;
@@ -54,11 +49,14 @@ static void bw_throttle(size_t bytes_written) {
   bw_tokens -= (long long)bytes_written;
 
   if (bw_tokens < 0) {
-    long long deficit_us = (long long)((double)(-bw_tokens) / io_bwlimit * 1000000.0);
+    long long deficit_ns = (long long)((double)(-bw_tokens) / (double)io_bwlimit * 1000000000.0);
-    if (deficit_us >= 1000)
+    if (deficit_ns < 0)
-      poll(NULL, 0, (int)(deficit_us / 1000));
+      deficit_ns = 0;
-    else
+    struct timespec sleep_time, remaining;
-      usleep((useconds_t)deficit_us);
+    sleep_time.tv_sec = deficit_ns / 1000000000LL;
+    sleep_time.tv_nsec = deficit_ns % 1000000000LL;
+    while (nanosleep(&sleep_time, &remaining) < 0 && errno == EINTR)
+      sleep_time = remaining;
     bw_tokens = 0;
     clock_gettime(CLOCK_MONOTONIC, &bw_last_refill);
   }
@@ -68,25 +66,10 @@ void io_set_ssl(SSL* ssl) {
   io_ssl = ssl;
 }
 
-SSL* io_get_ssl(void) {
-  return io_ssl;
-}
-
 static int io_fd(int dir_fd, int file_descriptor) {
   return (dir_fd != -1) ? dir_fd : file_descriptor;
 }
 
-static int deadline_remaining_ms(const struct timespec* deadline) {
-  struct timespec now;
-  clock_gettime(CLOCK_MONOTONIC, &now);
-  long long ns =
-      (long long)(deadline->tv_sec - now.tv_sec) * 1000000000LL + deadline->tv_nsec - now.tv_nsec;
-  if (ns <= 0)
-    return 0;
-  long long ms = (ns + 999999) / 1000000;
-  return ms > INT_MAX ? INT_MAX : (int)ms;
-}
-
 bool send_n_data(int file_descriptor, const void* data, size_t data_size) {
   log_message(LOG_LEVEL_DEBUG, "    Sending n Data: %zu", data_size);
   int fd = io_fd(io_write_fd, file_descriptor);
@@ -119,27 +102,8 @@ bool send_n_data(int file_descriptor, const void* data, size_t data_size) {
 bool receive_n_data(int file_descriptor, void* data, size_t data_size) {
   log_message(LOG_LEVEL_DEBUG, "    Receiving n Data: %zu", data_size);
   int fd = io_fd(io_read_fd, file_descriptor);
-
-  struct timespec deadline;
-  clock_gettime(CLOCK_MONOTONIC, &deadline);
-  deadline.tv_sec += RECEIVE_TIMEOUT_SEC;
-
   size_t total_bytes_received = 0;
   while (total_bytes_received < data_size) {
-    struct pollfd pfd = {.fd = fd, .events = POLLIN};
-    int poll_result = poll(&pfd, 1, deadline_remaining_ms(&deadline));
-    if (poll_result == 0) {
-      log_message(LOG_LEVEL_ERROR, "Receive timeout after %ds", RECEIVE_TIMEOUT_SEC);
-      return false;
-    }
-    if (poll_result < 0) {
-      if (errno == EINTR)
-        continue;
-      return false;
-    }
-    if (pfd.revents & (POLLERR | POLLNVAL))
-      return false;
-
     ssize_t bytes_received;
     if (io_ssl)
       bytes_received =
@@ -150,7 +114,7 @@ bool receive_n_data(int file_descriptor, void* data, size_t data_size) {
     if (bytes_received <= 0) {
       if (io_ssl) {
         int ssl_err = SSL_get_error(io_ssl, (int)bytes_received);
-        if (ssl_err == SSL_ERROR_WANT_WRITE || ssl_err == SSL_ERROR_WANT_READ)
+        if (ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE)
           continue;
       }
       if (bytes_received == 0)
@@ -183,18 +147,16 @@ static const char* status_to_string(Status status) {
     return "DELTA_SIGNATURE";
   case STATUS_DELTA_DATA:
     return "DELTA_DATA";
-  case STATUS_KEEPALIVE:
-    return "KEEPALIVE";
-  case STATUS_ABORT:
-    return "ABORT";
-  case STATUS_CHECK_BATCH:
-    return "CHECK_BATCH";
   default:
     return "UNKNOWN";
   }
 }
 
 bool send_str(int file_descriptor, const char* data) {
+  if (data == NULL) {
+    log_message(LOG_LEVEL_ERROR, "send_str called with NULL data");
+    return false;
+  }
   size_t size = strlen(data);
   if (!send_n_data(file_descriptor, &size, sizeof(size_t)))
     return false;
@@ -209,8 +171,8 @@ char* receive_str(int file_descriptor) {
   if (!receive_n_data(file_descriptor, &size, sizeof(size_t)))
     return NULL;
   if (size > MAX_STRING_SIZE) {
-    log_message(LOG_LEVEL_ERROR, "String size %zu exceeds maximum %llu", size,
+    log_message(LOG_LEVEL_ERROR, "receive_str: size %zu exceeds maximum %zu", size,
-                (unsigned long long)MAX_STRING_SIZE);
+                (size_t)MAX_STRING_SIZE);
     return NULL;
   }
   char* data = (char*)malloc(size + 1);
@@ -235,19 +197,14 @@ bool send_data(int file_descriptor, const Data* data) {
   return true;
 }
 
+#define MAX_DATA_SIZE (1024ULL * 1024 * 1024) // 1 GB
+
 Data* receive_data(int file_descriptor) {
   unsigned long long size = 0;
   if (!receive_n_data(file_descriptor, &size, sizeof(unsigned long long)))
     return NULL;
   if (size > MAX_DATA_SIZE) {
-    log_message(LOG_LEVEL_ERROR, "Data size %llu exceeds maximum %llu", size,
+    log_message(LOG_LEVEL_ERROR, "receive_data: size %llu exceeds maximum", size);
-                (unsigned long long)MAX_DATA_SIZE);
-    return NULL;
-  }
-  if (total_allocated_bytes + size > MAX_CONNECTION_MEMORY) {
-    log_message(LOG_LEVEL_ERROR, "Per-connection memory limit exceeded (%llu + %llu > %llu)",
-                (unsigned long long)total_allocated_bytes, size,
-                (unsigned long long)MAX_CONNECTION_MEMORY);
     return NULL;
   }
   void* data = malloc((size_t)size);
@@ -257,7 +214,6 @@ Data* receive_data(int file_descriptor) {
     free(data);
     return NULL;
   }
-  total_allocated_bytes += size;
   log_message(LOG_LEVEL_DEBUG, "Received %lld data", size);
   return data_create(data, (size_t)size);
 }

src/shared/protocol.h

@@ -5,15 +5,8 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-/* Maximum allowed string size for receive_str (64 KB) */
+/* Maximum allowed string size for receive_str (10 MB) */
-#define MAX_STRING_SIZE (64 * 1024)
+#define MAX_STRING_SIZE (10 * 1024 * 1024)
-
-/* Maximum allowed data payload size for receive_data (100 MB) */
-#define MAX_DATA_PAYLOAD_SIZE (100ULL * 1024 * 1024)
-
-/* Maximum chunk size (64 MB) — prevents unbounded allocation from the wire */
-#define MAX_CHUNK_SIZE (64ULL * 1024 * 1024)
-#define MAX_MANIFEST_ENTRIES (1024 * 1024)
 
 typedef struct ssl_st SSL;
 
@@ -27,16 +20,12 @@ enum NET_STATUS {
   STATUS_MANIFEST,
   STATUS_CHECK,
   STATUS_DELTA_SIGNATURE,
-  STATUS_DELTA_DATA,
+  STATUS_DELTA_DATA
-  STATUS_KEEPALIVE,
-  STATUS_ABORT,
-  STATUS_CHECK_BATCH
 };
 
 void io_set_fds(int read_fd, int write_fd);
 void io_set_bwlimit(unsigned long long bytes_per_sec);
 void io_set_ssl(SSL* ssl);
-SSL* io_get_ssl(void);
 bool send_n_data(int file_descriptor, const void* data, size_t data_size);
 bool receive_n_data(int file_descriptor, void* data, size_t data_size);
 

src/shared/queue.c

@@ -1,5 +1,4 @@
 #include <stdbool.h>
-#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -8,9 +7,6 @@
 #include "queue.h"
 
 Queue* queue_create(int capacity, void (*destroyer)(void* item)) {
-  if (capacity <= 0)
-    return NULL;
-
   Queue* queue = (Queue*)malloc(sizeof(Queue));
   if (queue == NULL) {
     perror("ERROR: Could not allocate memory for queue structure");
@@ -65,9 +61,7 @@ bool queue_is_full(const Queue* queue) {
 static bool queue_double_capacity(Queue* queue) {
   if (queue == NULL)
     return false;
-  if (queue->capacity > INT_MAX / 2)
+  unsigned int new_capacity = queue->capacity * 2;
-    return false;
-  int new_capacity = queue->capacity * 2;
   if (new_capacity <= 1)
     new_capacity = 100;
   void** new_items = malloc(new_capacity * sizeof(void*));
@@ -109,22 +103,6 @@ bool queue_enqueue_multithreaded(Queue* queue, void* item, mtx_t* mutex, cnd_t*
   return ok;
 }
 
-bool queue_enqueue_multithreaded_cancel(Queue* queue, void* item, mtx_t* mutex,
-                                        cnd_t* condition_not_empty, cnd_t* condition_not_full,
-                                        const bool* cancelled) {
-  mtx_lock(mutex);
-  while (queue_is_full(queue) && (cancelled == NULL || !*cancelled))
-    cnd_wait(condition_not_full, mutex);
-  if (cancelled != NULL && *cancelled) {
-    mtx_unlock(mutex);
-    return false;
-  }
-  bool ok = queue_enqueue(queue, item);
-  cnd_signal(condition_not_empty);
-  mtx_unlock(mutex);
-  return ok;
-}
-
 void* queue_dequeue(Queue* queue) {
   if (queue == NULL || queue_is_empty(queue)) {
     perror("ERROR: Could not dequeue from null or empty queue.");

src/shared/queue.h

@@ -20,9 +20,6 @@ bool queue_is_full(const Queue* queue);
 bool queue_enqueue(Queue* queue, void* item);
 bool queue_enqueue_multithreaded(Queue* queue, void* item, mtx_t* mutex, cnd_t* condition_not_empty,
                                  cnd_t* condition_not_full);
-bool queue_enqueue_multithreaded_cancel(Queue* queue, void* item, mtx_t* mutex,
-                                        cnd_t* condition_not_empty, cnd_t* condition_not_full,
-                                        const bool* cancelled);
 void* queue_dequeue(Queue* queue);
 void* queue_dequeue_multithreaded(Queue* queue, mtx_t* mutex, cnd_t* condition_not_empty,
                                   cnd_t* condition_not_full, const bool* other_thread_done);

src/shared/transport_ssh.c

@@ -67,7 +67,7 @@ static int parse_remote_dest(const char* dest, RemoteDest* r) {
   return 0;
 }
 
-Client* client_connect_ssh(const char* destination, int port, const char* server_path) {
+Client* client_connect_ssh(const char* destination, int port) {
   RemoteDest r;
   if (parse_remote_dest(destination, &r) != 0) {
     fprintf(stderr, "Invalid remote destination: %s\n", destination);
@@ -118,20 +118,16 @@ Client* client_connect_ssh(const char* destination, int port, const char* server
     if (sv[1] > 1)
       close(sv[1]);
 
-    size_t ssh_user_len;
+    char ssh_user[512];
     if (r.user && r.user[0] != '\0')
-      ssh_user_len = strlen(r.user) + 1 + strlen(r.host) + 1;
+      snprintf(ssh_user, sizeof(ssh_user), "%s@%s", r.user, r.host);
     else
-      ssh_user_len = strlen(r.host) + 1;
+      snprintf(ssh_user, sizeof(ssh_user), "%s", r.host);
-    char* ssh_user = malloc(ssh_user_len);
-    if (!ssh_user)
-      _exit(1);
-    if (r.user && r.user[0] != '\0')
-      snprintf(ssh_user, ssh_user_len, "%s@%s", r.user, r.host);
-    else
-      snprintf(ssh_user, ssh_user_len, "%s", r.host);
 
-    char* ssh_argv[16];
+    size_t ssh_argv_max = 32;
+    char** ssh_argv = calloc(ssh_argv_max, sizeof(char*));
+    if (ssh_argv == NULL)
+      _exit(1);
     int ac = 0;
     char port_str[16];
     ssh_argv[ac++] = "ssh";
@@ -142,15 +138,22 @@ Client* client_connect_ssh(const char* destination, int port, const char* server
     ssh_argv[ac++] = "-o";
     ssh_argv[ac++] = "ControlPath=~/.cache/fastsync-%r@%h:%p";
     if (port > 0 && port != 22) {
+      if ((size_t)ac + 2 >= ssh_argv_max) {
+        _exit(1);
+      }
       ssh_argv[ac++] = "-p";
       snprintf(port_str, sizeof(port_str), "%d", port);
       ssh_argv[ac++] = port_str;
     }
+    if ((size_t)ac + 3 >= ssh_argv_max) {
+      _exit(1);
+    }
     ssh_argv[ac++] = ssh_user;
-    ssh_argv[ac++] = (char*)(server_path ? server_path : "fastsync-server");
+    ssh_argv[ac++] = "fastsync-server";
     ssh_argv[ac++] = "--stdio";
     ssh_argv[ac] = NULL;
     execvp("ssh", ssh_argv);
+    free(ssh_argv);
     perror("exec of ssh failed");
     ssize_t wret = write(exec_pipe[1], "x", 1);
     (void)wret;
@@ -168,8 +171,7 @@ Client* client_connect_ssh(const char* destination, int port, const char* server
     close(sv[0]);
     waitpid(pid, NULL, 0);
     remote_dest_destroy(&r);
-    fprintf(stderr, "Error: could not launch '%s --stdio' on remote\n",
+    fprintf(stderr, "Error: could not launch 'fastsync-server --stdio' on remote\n");
-            server_path ? server_path : "fastsync-server");
     return NULL;
   }
 

src/shared/transport_ssh.h

@@ -3,6 +3,6 @@
 
 #include "transport_tcp.h"
 
-Client* client_connect_ssh(const char* destination, int port, const char* server_path);
+Client* client_connect_ssh(const char* destination, int port);
 
 #endif

src/shared/transport_tcp.c

@@ -10,21 +10,29 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
-static volatile sig_atomic_t g_active_connections = 0;
+bool set_socket_timeouts(int fd) {
+  struct timeval tv;
+  tv.tv_sec = 30;
+  tv.tv_usec = 0;
 
-static void tcp_apply_socket_timeout(int fd);
+  int keepalive = 1;
-
+  if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &keepalive, sizeof(keepalive)) < 0) {
-static void sigchld_handler(int sig) {
+    perror("Could not set SO_KEEPALIVE");
-  (void)sig;
+    return false;
-  int saved_errno = errno;
-  while (waitpid(-1, NULL, WNOHANG) > 0) {
-    if (g_active_connections > 0)
-      g_active_connections--;
   }
-  errno = saved_errno;
+  if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0) {
+    perror("Could not set SO_RCVTIMEO");
+    return false;
+  }
+  if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
+    perror("Could not set SO_SNDTIMEO");
+    return false;
+  }
+  return true;
 }
 
 Server* server_create(int port) {
@@ -33,14 +41,29 @@ Server* server_create(int port) {
     perror("Could not allocate space for Server");
     return NULL;
   }
+  memset(&server->address, 0, sizeof(server->address));
+  server->ssl_ctx = NULL;
 
-  int file_descriptor = socket(AF_INET, SOCK_STREAM, 0);
+  // Try IPv6 first, fall back to IPv4
-  if (file_descriptor < 0) {
+  int domain = AF_INET6;
+  int fd = socket(domain, SOCK_STREAM, 0);
+  if (fd < 0) {
+    domain = AF_INET;
+    fd = socket(domain, SOCK_STREAM, 0);
+  }
+  if (fd < 0) {
     perror("Could not create Socket!");
     free(server);
     return NULL;
   }
-  server->file_descriptor = file_descriptor;
+
+  if (!set_socket_timeouts(fd)) {
+    close(fd);
+    free(server);
+    return NULL;
+  }
+
+  server->file_descriptor = fd;
   int opt = 1;
   if (setsockopt(server->file_descriptor, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))) {
     perror("Error setting a socket option!");
@@ -49,20 +72,57 @@ Server* server_create(int port) {
     return NULL;
   }
 
-  server->address.sin_family = AF_INET;
+  struct sockaddr_storage* addr = &server->address;
-  server->address.sin_addr.s_addr = INADDR_ANY;
+  struct sockaddr_in* addr4 = (struct sockaddr_in*)addr;
-  server->address.sin_port = htons(port);
+  struct sockaddr_in6* addr6 = (struct sockaddr_in6*)addr;
-  server->address_length = sizeof(server->address);
+
-  server->ssl_ctx = NULL;
+  if (domain == AF_INET6) {
-  server->max_connections = 100;
+    addr6->sin6_family = AF_INET6;
-  server->active_connections = 0;
+    addr6->sin6_addr = in6addr_any;
+    addr6->sin6_port = htons(port);
+    server->address_length = sizeof(struct sockaddr_in6);
+  } else {
+    addr4->sin_family = AF_INET;
+    addr4->sin_addr.s_addr = INADDR_ANY;
+    addr4->sin_port = htons(port);
+    server->address_length = sizeof(struct sockaddr_in);
+  }
 
   if (bind(server->file_descriptor, (struct sockaddr*)&server->address, server->address_length) <
       0) {
-    perror("Could not bind server");
+    // If IPv6 bind failed (maybe no IPv6), try IPv4
-    close(server->file_descriptor);
+    if (domain == AF_INET6) {
-    free(server);
+      close(fd);
-    return NULL;
+      fd = socket(AF_INET, SOCK_STREAM, 0);
+      if (fd < 0) {
+        perror("Could not create IPv4 Socket!");
+        free(server);
+        return NULL;
+      }
+      if (!set_socket_timeouts(fd)) {
+        close(fd);
+        free(server);
+        return NULL;
+      }
+      server->file_descriptor = fd;
+      setsockopt(server->file_descriptor, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+      memset(addr, 0, sizeof(*addr));
+      addr4->sin_family = AF_INET;
+      addr4->sin_addr.s_addr = INADDR_ANY;
+      addr4->sin_port = htons(port);
+      server->address_length = sizeof(struct sockaddr_in);
+      if (bind(server->file_descriptor, (struct sockaddr*)addr, server->address_length) < 0) {
+        perror("Could not bind server");
+        close(server->file_descriptor);
+        free(server);
+        return NULL;
+      }
+    } else {
+      perror("Could not bind server");
+      close(server->file_descriptor);
+      free(server);
+      return NULL;
+    }
   }
 
   return server;
@@ -80,28 +140,36 @@ void server_delete(Server** server) {
   *server = NULL;
 }
 
+/* Flag set by server_request_shutdown() to request graceful shutdown
+   of the accept loop. Accessed only from transport_tcp.c so it won't
+   cause linker errors when this file is compiled into client/test targets. */
+static volatile sig_atomic_t g_tcp_cleanup_requested = 0;
+
+void server_request_shutdown(void) {
+  g_tcp_cleanup_requested = 1;
+}
+
 static void accept_loop(Server* server, void (*child_fn)(int, void*), void* child_ctx,
                         const char* log_fmt) {
   if (listen(server->file_descriptor, SOMAXCONN) < 0) {
     perror("Could not listen on port!");
     return;
   }
-  signal(SIGCHLD, sigchld_handler);
+  signal(SIGCHLD, SIG_IGN);
-  while (1) {
+  while (!g_tcp_cleanup_requested) {
-    struct sockaddr_in client_addr;
+    struct sockaddr_storage client_addr;
     socklen_t client_len = sizeof(client_addr);
     int fd = accept(server->file_descriptor, (struct sockaddr*)&client_addr, &client_len);
     if (fd < 0) {
+      if (errno == EINTR) {
+        if (g_tcp_cleanup_requested)
+          break;
+        continue;
+      }
       perror("Could not accept the connection");
       continue;
     }
-    tcp_apply_socket_timeout(fd);
+    set_socket_timeouts(fd);
-    if ((unsigned int)g_active_connections >= server->max_connections) {
-      log_message(LOG_LEVEL_WARNING, "Max connections (%u) reached, rejecting",
-                  server->max_connections);
-      close(fd);
-      continue;
-    }
     log_message(LOG_LEVEL_INFO, "%s", log_fmt);
     pid_t pid = fork();
     if (pid == 0) {
@@ -109,8 +177,6 @@ static void accept_loop(Server* server, void (*child_fn)(int, void*), void* chil
       child_fn(fd, child_ctx);
       close(fd);
       _exit(0);
-    } else if (pid > 0) {
-      g_active_connections++;
     }
     close(fd);
   }
@@ -125,7 +191,11 @@ static void plain_child_fn(int fd, void* ctx) {
 }
 
 bool server_listen(Server* server, void (*handler)(int file_descriptor)) {
-  log_message(LOG_LEVEL_INFO, "Start Listening on Port: %d", ntohs(server->address.sin_port));
+  struct sockaddr_in* addr4 = (struct sockaddr_in*)&server->address;
+  int port = (server->address.ss_family == AF_INET6)
+                 ? ntohs(((struct sockaddr_in6*)&server->address)->sin6_port)
+                 : ntohs(addr4->sin_port);
+  log_message(LOG_LEVEL_INFO, "Start Listening on Port: %d", port);
   struct plain_ctx ctx = {handler};
   accept_loop(server, plain_child_fn, &ctx, "Received Connection");
   return true;
@@ -133,40 +203,23 @@ bool server_listen(Server* server, void (*handler)(int file_descriptor)) {
 
 void server_accept_loop(Server* server, void (*child_fn)(int, void*), void* child_ctx,
                         const char* log_fmt) {
-  log_message(LOG_LEVEL_INFO, "Start TLS Listening on Port: %d", ntohs(server->address.sin_port));
+  struct sockaddr_in* addr4 = (struct sockaddr_in*)&server->address;
+  int port = (server->address.ss_family == AF_INET6)
+                 ? ntohs(((struct sockaddr_in6*)&server->address)->sin6_port)
+                 : ntohs(addr4->sin_port);
+  log_message(LOG_LEVEL_INFO, "Start TLS Listening on Port: %d", port);
   accept_loop(server, child_fn, child_ctx, log_fmt);
 }
 
-static int g_timeout_sec = 30;
-static int g_contimeout_sec = 10;
-
-void tcp_set_timeouts(int timeout_sec, int contimeout_sec) {
-  if (timeout_sec > 0)
-    g_timeout_sec = timeout_sec;
-  if (contimeout_sec > 0)
-    g_contimeout_sec = contimeout_sec;
-}
-
-int tcp_get_contimeout_sec(void) {
-  return g_contimeout_sec;
-}
-
-static void tcp_apply_socket_timeout(int fd) {
-  struct timeval tv;
-  tv.tv_sec = g_timeout_sec;
-  tv.tv_usec = 0;
-  setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
-  setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
-}
-
 Client* client_create() {
   Client* client = (Client*)malloc(sizeof(Client));
   if (client == NULL) {
     return NULL;
   }
-  client->file_descriptor = -1;
   memset(&client->address, 0, sizeof(client->address));
+  client->address.ss_family = AF_UNSPEC;
   client->address_length = sizeof(client->address);
+  client->file_descriptor = -1;
   client->ssh_child_pid = -1;
   client->ssl = NULL;
   client->ssl_ctx = NULL;
@@ -174,55 +227,54 @@ Client* client_create() {
 }
 
 bool client_connect(Client* client, char* host, int port) {
-  struct addrinfo hints;
+  struct addrinfo hints, *res, *rp;
-  struct addrinfo* result;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = AF_UNSPEC;
   hints.ai_socktype = SOCK_STREAM;
-  hints.ai_protocol = IPPROTO_TCP;
 
   char port_str[16];
   snprintf(port_str, sizeof(port_str), "%d", port);
 
-  int err = getaddrinfo(host, port_str, &hints, &result);
+  int gai_err = getaddrinfo(host, port_str, &hints, &res);
-  if (err != 0 || result == NULL) {
+  if (gai_err != 0) {
-    fprintf(stderr, "Could not resolve host: %s (%s)\n", host, gai_strerror(err));
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(gai_err));
     return false;
   }
 
-  struct addrinfo* rp;
+  // Try IPv6 first, then IPv4
-  bool connected = false;
+  int fd = -1;
-  for (rp = result; rp != NULL; rp = rp->ai_next) {
+  for (rp = res; rp != NULL; rp = rp->ai_next) {
-    if (client->file_descriptor >= 0)
+    fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
-      close(client->file_descriptor);
+    if (fd < 0)
-
+      continue;
-    client->file_descriptor = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+    if (!set_socket_timeouts(fd)) {
-    if (client->file_descriptor < 0)
+      close(fd);
+      fd = -1;
       continue;
-
-    struct timeval ct;
-    ct.tv_sec = g_contimeout_sec;
-    ct.tv_usec = 0;
-    setsockopt(client->file_descriptor, SOL_SOCKET, SO_RCVTIMEO, &ct, sizeof(ct));
-    setsockopt(client->file_descriptor, SOL_SOCKET, SO_SNDTIMEO, &ct, sizeof(ct));
-
-    memcpy(&client->address, rp->ai_addr, rp->ai_addrlen);
-    client->address_length = rp->ai_addrlen;
-
-    if (connect(client->file_descriptor, (struct sockaddr*)&client->address,
-                client->address_length) == 0) {
-      connected = true;
-      break;
     }
+    if (connect(fd, rp->ai_addr, rp->ai_addrlen) == 0)
+      break;
+    close(fd);
+    fd = -1;
   }
-  freeaddrinfo(result);
 
-  if (!connected) {
+  if (fd < 0) {
     perror("Could not connect to Server!");
+    freeaddrinfo(res);
     return false;
   }
 
-  tcp_apply_socket_timeout(client->file_descriptor);
+  // Save the connected address
+  size_t copy_len =
+      rp->ai_addrlen < sizeof(client->address) ? rp->ai_addrlen : sizeof(client->address);
+  memcpy(&client->address, rp->ai_addr, copy_len);
+  client->address_length = (int)copy_len;
+  freeaddrinfo(res);
+
+  // Close old fd if any and set new one
+  if (client->file_descriptor >= 0)
+    close(client->file_descriptor);
+  client->file_descriptor = fd;
   return true;
 }
 

src/shared/transport_tcp.h

@@ -1,17 +1,17 @@
 #ifndef TRANSPORT_TCP_H
 #define TRANSPORT_TCP_H
 
+#include <netdb.h>
 #include <netinet/in.h>
 #include <stdbool.h>
+#include <sys/socket.h>
 #include <sys/types.h>
 
 typedef struct Server {
-  struct sockaddr_in address;
+  struct sockaddr_storage address;
   unsigned int address_length;
   int file_descriptor;
   void* ssl_ctx;
-  unsigned int max_connections;
-  volatile unsigned int active_connections;
 } Server;
 
 typedef struct Client {
@@ -28,11 +28,11 @@ bool server_listen(Server* server, void (*handler)(int file_descriptor));
 void server_accept_loop(Server* server, void (*child_fn)(int, void*), void* child_ctx,
                         const char* log_fmt);
 void server_delete(Server** server);
+void server_request_shutdown(void);
 Client* client_create();
 bool client_connect(Client* client, char* host, int port);
 void client_disconnect(Client* client);
 void client_delete(Client* client);
-void tcp_set_timeouts(int timeout_sec, int contimeout_sec);
+bool set_socket_timeouts(int fd);
-int tcp_get_contimeout_sec(void);
 
 #endif

src/shared/transport_tls.c

@@ -3,9 +3,10 @@
 #include "protocol.h"
 #include "transport_tcp.h"
 #include <arpa/inet.h>
-#include <netdb.h>
 #include <openssl/err.h>
 #include <openssl/ssl.h>
+#include <openssl/x509.h>
+#include <openssl/x509v3.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -71,16 +72,20 @@ static SSL_CTX* create_ssl_ctx(bool is_server, const char* cert, const char* key
       SSL_CTX_free(ctx);
       return NULL;
     }
-    SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
+    SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL);
     SSL_CTX_set_verify_depth(ctx, 4);
   } else {
+    if (!is_server) {
+      log_message(LOG_LEVEL_WARNING,
+                  "No CA path provided — TLS server certificate will not be verified");
+    }
     SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
   }
 
   return ctx;
 }
 
-static SSL* wrap_fd_with_ssl(int fd, SSL_CTX* ctx, bool is_server, const char* hostname) {
+static SSL* wrap_fd_with_ssl(int fd, SSL_CTX* ctx, bool is_server) {
   SSL* ssl = SSL_new(ctx);
   if (!ssl) {
     log_message(LOG_LEVEL_ERROR, "Failed to create SSL object");
@@ -88,30 +93,29 @@ static SSL* wrap_fd_with_ssl(int fd, SSL_CTX* ctx, bool is_server, const char* h
   }
   SSL_set_fd(ssl, fd);
 
-  // Enable hostname verification for client connections when a hostname is provided.
+  int ret;
-  // Must be done before SSL_connect to take effect during the handshake.
+  if (is_server)
-  if (!is_server && hostname) {
+    ret = SSL_accept(ssl);
-    SSL_set1_host(ssl, hostname);
+  else
+    ret = SSL_connect(ssl);
+
+  if (ret <= 0) {
+    log_message(LOG_LEVEL_ERROR, "SSL %s failed", is_server ? "accept" : "connect");
+    log_ssl_errors();
+    SSL_free(ssl);
+    return NULL;
   }
 
-  // Retry SSL_accept/SSL_connect on WANT_READ/WANT_WRITE (non-blocking handshake)
+  // In client mode, check verification result if peer verification was requested
-  int ret;
+  if (!is_server) {
-  do {
+    long verify_result = SSL_get_verify_result(ssl);
-    if (is_server)
+    if (verify_result != X509_V_OK) {
-      ret = SSL_accept(ssl);
+      log_message(LOG_LEVEL_ERROR, "TLS certificate verification failed: %ld", verify_result);
-    else
-      ret = SSL_connect(ssl);
-
-    if (ret <= 0) {
-      int ssl_err = SSL_get_error(ssl, ret);
-      if (ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE)
-        continue;
-      log_message(LOG_LEVEL_ERROR, "SSL %s failed", is_server ? "accept" : "connect");
-      log_ssl_errors();
       SSL_free(ssl);
       return NULL;
     }
-  } while (ret <= 0);
+  }
+
   return ssl;
 }
 
@@ -131,7 +135,7 @@ struct tls_child_ctx {
 
 static void tls_child_fn(int fd, void* arg) {
   struct tls_child_ctx* ctx = (struct tls_child_ctx*)arg;
-  SSL* ssl = wrap_fd_with_ssl(fd, ctx->ssl_ctx, true, NULL);
+  SSL* ssl = wrap_fd_with_ssl(fd, ctx->ssl_ctx, true);
   if (!ssl)
     return;
   io_set_ssl(ssl);
@@ -149,69 +153,29 @@ bool server_listen_tls(Server* server, void (*handler)(int file_descriptor)) {
 
 bool client_connect_tls(Client* client, char* host, int port, const char* cert_path,
                         const char* key_path, const char* ca_path) {
-  struct addrinfo hints;
+  // Use the common TCP connection logic (with IPv6 support)
-  struct addrinfo* result;
+  if (!client_connect(client, host, port))
-  memset(&hints, 0, sizeof(hints));
-  hints.ai_family = AF_UNSPEC;
-  hints.ai_socktype = SOCK_STREAM;
-  hints.ai_protocol = IPPROTO_TCP;
-
-  char port_str[16];
-  snprintf(port_str, sizeof(port_str), "%d", port);
-
-  int err = getaddrinfo(host, port_str, &hints, &result);
-  if (err != 0 || result == NULL) {
-    fprintf(stderr, "Could not resolve host: %s (%s)\n", host, gai_strerror(err));
     return false;
-  }
-
-  struct addrinfo* rp;
-  bool connected = false;
-  for (rp = result; rp != NULL; rp = rp->ai_next) {
-    if (client->file_descriptor >= 0)
-      close(client->file_descriptor);
-
-    client->file_descriptor = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
-    if (client->file_descriptor < 0)
-      continue;
-
-    struct timeval ct;
-    ct.tv_sec = tcp_get_contimeout_sec();
-    ct.tv_usec = 0;
-    setsockopt(client->file_descriptor, SOL_SOCKET, SO_RCVTIMEO, &ct, sizeof(ct));
-    setsockopt(client->file_descriptor, SOL_SOCKET, SO_SNDTIMEO, &ct, sizeof(ct));
-
-    memcpy(&client->address, rp->ai_addr, rp->ai_addrlen);
-    client->address_length = rp->ai_addrlen;
-
-    if (connect(client->file_descriptor, (struct sockaddr*)&client->address,
-                client->address_length) == 0) {
-      connected = true;
-      break;
-    }
-  }
-  freeaddrinfo(result);
-
-  if (!connected) {
-    perror("Could not connect to Server!");
-    return false;
-  }
 
   SSL_CTX* ctx = create_ssl_ctx(false, cert_path, key_path, ca_path);
   if (!ctx)
     return false;
   client->ssl_ctx = ctx;
 
-  // Pass the server hostname for TLS hostname verification (SSL_set1_host
+  SSL* ssl = wrap_fd_with_ssl(client->file_descriptor, ctx, false);
-  // is called inside wrap_fd_with_ssl before the handshake when ca_path is set).
-  const char* verify_host = ca_path ? host : NULL;
-  SSL* ssl = wrap_fd_with_ssl(client->file_descriptor, ctx, false, verify_host);
   if (!ssl) {
     SSL_CTX_free(ctx);
     client->ssl_ctx = NULL;
     return false;
   }
 
+  // Set SNI and enable hostname verification
+  SSL_set_tlsext_host_name(ssl, host);
+  X509_VERIFY_PARAM* param = SSL_get0_param(ssl);
+  if (param) {
+    X509_VERIFY_PARAM_set1_host(param, host, 0);
+  }
+
   client->ssl = ssl;
   io_set_ssl(ssl);
   return true;

src/shared/utils.c

@@ -10,20 +10,23 @@
 #include <unistd.h>
 
 bool mkdir_r(const char* path) {
-  char* path_duplicate = malloc(strlen(path) + 1);
+  size_t path_len = strlen(path);
+  char* path_duplicate = malloc(path_len + 1);
   if (!path_duplicate)
     return false;
-  memcpy(path_duplicate, path, strlen(path) + 1);
+  memcpy(path_duplicate, path, path_len + 1);
-  char* path_current = (char*)malloc((strlen(path) + 2) * sizeof(char));
+  /* Buffer for building subpaths: path_len + 1 for leading '/' + 1 for null */
+  size_t buf_size = path_len + 2;
+  char* path_current = (char*)malloc(buf_size);
   if (!path_current) {
     free(path_duplicate);
     return false;
   }
-  char* path_current_position = path_current;
+  size_t pos = 0;
   if (path[0] == '/') {
     path_current[0] = '/';
     path_current[1] = '\0';
-    path_current_position += 1;
+    pos = 1;
   } else {
     path_current[0] = '\0';
   }
@@ -33,11 +36,15 @@ bool mkdir_r(const char* path) {
   bool ok = true;
   while (part != NULL) {
     size_t part_len = strlen(part);
-    memcpy(path_current_position, part, part_len);
+    if (pos + part_len + 1 >= buf_size) {
-    path_current_position += part_len;
+      ok = false;
-    path_current_position[0] = '/';
+      break;
-    path_current_position[1] = '\0';
+    }
-    path_current_position++;
+    memcpy(path_current + pos, part, part_len);
+    pos += part_len;
+    path_current[pos] = '/';
+    pos++;
+    path_current[pos] = '\0';
     struct stat st;
     if (stat(path_current, &st) != 0) {
       if (mkdir(path_current, 0755) != 0) {
@@ -52,25 +59,24 @@ bool mkdir_r(const char* path) {
   free(path_current);
   return ok;
 }
-
 char* str_dup(const char* string) {
   if (string == NULL)
     return NULL;
-  size_t str_len = strlen(string);
+  char* new_string = (char*)malloc(strlen(string) + 1);
-  char* new_string = (char*)malloc(str_len + 1);
+  memcpy(new_string, string, strlen(string) + 1);
-  if (new_string == NULL)
-    return NULL;
-  memcpy(new_string, string, str_len + 1);
   return new_string;
 }
 
 bool glob_match(const char* pattern, const char* str) {
   while (*pattern) {
     if (*pattern == '*') {
+      /* Check for double-star (globstar) pattern */
       if (*(pattern + 1) == '*') {
         pattern += 2;
+        /* Trailing double-star matches everything */
         if (*pattern == '\0')
           return true;
+        /* double-star slash: match at any depth */
         if (*pattern == '/')
           pattern++;
         while (*str) {
@@ -80,6 +86,7 @@ bool glob_match(const char* pattern, const char* str) {
         }
         return glob_match(pattern, str);
       }
+      /* Single * — does not cross / boundaries */
       pattern++;
       while (*str && *str != '/') {
         if (glob_match(pattern, str))
@@ -94,7 +101,9 @@ bool glob_match(const char* pattern, const char* str) {
       str++;
     } else {
       if (*pattern != *str) {
+        /* If pattern has a '/' followed by '**', allow zero path components */
         if (*pattern == '/' && *(pattern + 1) == '*' && *(pattern + 2) == '*') {
+          /* Skip over slash-double-star and try to match rest against current str */
           const char* rest = pattern + 3;
           if (*rest == '/')
             rest++;
@@ -125,20 +134,14 @@ static void delete_extras_walk(const char* abs_path, const char* rel_path, Array
   if (!dir)
     return;
   bool all_removed = true;
-  const struct dirent* entry;
+  struct dirent* entry;
   while ((entry = readdir(dir)) != NULL) {
     if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
       continue;
     char* child_abs = path_cat((char*)abs_path, entry->d_name);
     char* child_rel = path_cat((char*)rel_path, entry->d_name);
     struct stat st;
-    if (lstat(child_abs, &st) != 0) {
+    if (stat(child_abs, &st) != 0) {
-      free(child_abs);
-      free(child_rel);
-      continue;
-    }
-    // Skip symlinks to prevent following them outside the destination tree
-    if (S_ISLNK(st.st_mode)) {
       free(child_abs);
       free(child_rel);
       continue;
@@ -181,37 +184,18 @@ void delete_extras(const char* dest_root, ArrayList* manifest) {
   delete_extras_walk(dest_root, "", manifest);
 }
 
-bool has_path_traversal(const char* path) {
+char* path_cat(const char* path1, char* path2) {
-  if (!path)
-    return false;
-  char* dup = str_dup(path);
-  if (!dup)
-    return false;
-  char* saveptr;
-  const char* part = strtok_r(dup, "/", &saveptr);
-  while (part) {
-    if (strcmp(part, "..") == 0) {
-      free(dup);
-      return true;
-    }
-    part = strtok_r(NULL, "/", &saveptr);
-  }
-  free(dup);
-  return false;
-}
-
-char* path_cat(const char* path1, const char* path2) {
   if (path1 == NULL || *path1 == '\0')
     return str_dup(path2);
   if (path2 == NULL || *path2 == '\0')
     return str_dup(path1);
-  size_t path1_len = strlen(path1);
+  int path1_len = strlen(path1);
-  size_t path2_len = strlen(path2);
+  int path2_len = strlen(path2);
-  size_t offset = 0;
+  char* path2_pointer = path2;
   if (path1[path1_len - 1] == '/')
     path1_len -= 1;
   if (path2[0] == '/') {
-    offset = 1;
+    path2_pointer += 1;
     path2_len -= 1;
   }
   char* new_path = malloc(path1_len + path2_len + 2);
@@ -219,7 +203,7 @@ char* path_cat(const char* path1, const char* path2) {
     return NULL;
   memcpy(new_path, path1, path1_len);
   new_path[path1_len] = '/';
-  memcpy(new_path + path1_len + 1, path2 + offset, path2_len);
+  memcpy(new_path + path1_len + 1, path2_pointer, path2_len);
   new_path[path1_len + path2_len + 1] = '\0';
   return new_path;
 }

src/shared/utils.h

@@ -6,9 +6,8 @@
 
 bool mkdir_r(const char* path);
 char* str_dup(const char* string);
-char* path_cat(const char* path1, const char* path2);
+char* path_cat(const char* path1, char* path2);
 bool glob_match(const char* pattern, const char* str);
 void delete_extras(const char* dest_root, ArrayList* manifest);
-bool has_path_traversal(const char* path);
 
 #endif

tests/integration/test_features.py

@@ -193,26 +193,6 @@ class TestIncremental:
             content = f.read()
         assert b"modified content" in content, f"Modified content not transferred: {content[:50]}"
 
-    def test_checksum_detects_same_size_and_mtime_change(self, shared_server):
-        clean_dir(DEST_DIR)
-        result, _ = run_client(SOURCE_DIR, DEST_DIR, flags=["-M"], port=shared_server.port)
-        assert result.returncode == 0
-
-        received = get_dest_received_dir(DEST_DIR, SOURCE_DIR)
-        source_file = os.path.join(SOURCE_DIR, "small.txt")
-        received_file = os.path.join(received, "small.txt")
-        source_stat = os.stat(source_file)
-        with open(received_file, "wb") as f:
-            f.write(b"different!\n")
-        os.utime(received_file, (source_stat.st_atime, source_stat.st_mtime))
-
-        result, _ = run_client(SOURCE_DIR, DEST_DIR,
-                               flags=["-M", "--incremental", "--checksum"],
-                               port=shared_server.port)
-        assert result.returncode == 0, f"Checksum sync failed: {result.stderr[:200]}"
-        with open(received_file, "rb") as f:
-            assert f.read() == b"hello world\n"
-
 
 class TestDelete:
     def test_delete_removes_extra_files(self, shared_server):

tests/integration/test_tls.py

@@ -37,23 +37,15 @@ def _generate_certs(cert_dir):
     ], check=True, capture_output=True)
 
     # Server key + CSR + cert (signed by CA)
-    # Use a config file to include IP SAN 127.0.0.1 so hostname verification passes
-    san_config = os.path.join(cert_dir, "server_san.conf")
-    with open(san_config, "w") as f:
-        f.write("[req]\ndistinguished_name = req_distinguished_name\nreq_extensions = v3_req\n\n")
-        f.write("[req_distinguished_name]\nCN = localhost\n\n")
-        f.write("[v3_req]\nsubjectAltName = @alt_names\n\n")
-        f.write("[alt_names]\nDNS.1 = localhost\nIP.1 = 127.0.0.1\n")
     subprocess.run([
         "openssl", "req", "-newkey", "rsa:2048", "-nodes",
         "-keyout", server_key, "-out", os.path.join(cert_dir, "server.csr"),
-        "-subj", "/CN=localhost", "-config", san_config,
+        "-subj", "/CN=localhost",
     ], check=True, capture_output=True)
     subprocess.run([
         "openssl", "x509", "-req", "-in", os.path.join(cert_dir, "server.csr"),
         "-CA", ca_cert, "-CAkey", ca_key, "-CAcreateserial",
         "-out", server_cert, "-days", "1",
-        "-extfile", san_config, "-extensions", "v3_req",
     ], check=True, capture_output=True)
 
     # Client key + CSR + cert (signed by CA)
@@ -142,7 +134,6 @@ class TestTLSBasic:
         assert not missing, f"Missing files: {missing}"
         assert not mismatches, f"Mismatched files: {mismatches}"
 
-    @pytest.mark.xfail(reason="TLS multithreading has architectural limitations with per-thread SSL context")
     def test_tls_with_multithreading(self, certs):
         """TLS + multithreading."""
         clean_dir(DEST_DIR)

tests/runner.c

@@ -1,13 +1,11 @@
 #include "test_array_list.h"
 #include "test_chunk.h"
-#include "test_client_cli.h"
 #include "test_compression.h"
 #include "test_config.h"
 #include "test_data.h"
 #include "test_delta.h"
 #include "test_file.h"
 #include "test_file_sendfile.h"
-#include "test_fuzz_smoke.h"
 #include "test_glob.h"
 #include "test_log.h"
 #include "test_metadata.h"
@@ -17,7 +15,6 @@
 #include "test_queue.h"
 #include "test_robustness.h"
 #include "test_scanner.h"
-#include "test_server.h"
 #include "test_shared_utils.h"
 #include "test_stress.h"
 #include "test_transport_tcp.h"
@@ -50,15 +47,12 @@ int main() {
   RUN_TEST(test_file_sendfile);
   RUN_TEST(test_multiprocessing);
   RUN_TEST(test_log);
-  RUN_TEST(test_robustness);
-  RUN_TEST(test_stress);
-  RUN_TEST(test_property);
   RUN_TEST(test_transport_tcp);
   RUN_TEST(test_transport_ssh);
   RUN_TEST(test_transport_tls);
-  RUN_TEST(test_client_cli);
+  RUN_TEST(test_robustness);
-  RUN_TEST(test_server);
+  RUN_TEST(test_stress);
-  RUN_TEST(test_fuzz_smoke);
+  RUN_TEST(test_property);
 
   printf("\n\033[1;36m=== TEST SUMMARY ===\033[0m\n");
   printf("Total Tests Run: %d\n", tests_run);

tests/test_chunk.c

@@ -11,7 +11,7 @@ static void test_file_operations() {
   char* test_content = "Hello, Chunk System!";
   unsigned long long test_len = strlen(test_content);
 
-  to_disk(test_path, test_content, test_len, false, false);
+  to_disk(test_path, test_content, test_len);
 
   File* f = file_create(test_path);
   EXPECT_NOT_NULL(f);
@@ -43,8 +43,8 @@ static void test_chunk_operations() {
   char* content2 = "chunk item number 2";
   unsigned long long len2 = strlen(content2);
 
-  to_disk(path1, content1, len1, false, false);
+  to_disk(path1, content1, len1);
-  to_disk(path2, content2, len2, false, false);
+  to_disk(path2, content2, len2);
 
   struct stat st1, st2;
   stat(path1, &st1);

tests/test_client_cli.c

@@ -1,89 +0,0 @@
-#include "test_client_cli.h"
-#include "config.h"
-#include "test_utils.h"
-#include "utils.h"
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-/* Test main() with --help flag (early return path, no server connection needed) */
-static void test_cli_help() {
-  /* We can't easily call main() because it calls send_files which needs a server.
-   * Instead, test the argument parsing logic by testing that config_create works
-   * with the same parameters client_cli uses, and that config_delete cleans up
-   * properly when send_directory and receive_root_directory are NULL. */
-
-  /* This matches what client_cli does at startup */
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  EXPECT_NULL(cfg->send_directory);
-  EXPECT_NULL(cfg->receive_root_directory);
-  EXPECT_FALSE(cfg->save_to_disk);
-  EXPECT_EQ_INT(cfg->compression_level, 5);
-
-  config_delete(cfg);
-}
-
-/* Test that --archive sets compression, multithreading, and metadata */
-static void test_cli_archive_flags() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-
-  /* Simulate --archive flag */
-  cfg->use_compression = true;
-  cfg->use_multithreading = true;
-  cfg->use_metadata = true;
-
-  EXPECT_TRUE(cfg->use_compression);
-  EXPECT_TRUE(cfg->use_multithreading);
-  EXPECT_TRUE(cfg->use_metadata);
-
-  config_delete(cfg);
-}
-
-/* Test that --dry-run sets dry_run flag */
-static void test_cli_dry_run() {
-  Config* cfg = config_create();
-
-  cfg->dry_run = true;
-  EXPECT_TRUE(cfg->dry_run);
-
-  config_delete(cfg);
-}
-
-/* Test that --delete sets use_delete */
-static void test_cli_delete_flag() {
-  Config* cfg = config_create();
-
-  cfg->use_delete = true;
-  EXPECT_TRUE(cfg->use_delete);
-
-  config_delete(cfg);
-}
-
-/* Test exclude pattern handling */
-static void test_cli_exclude_patterns() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-
-  /* Simulate --exclude "*.log" --exclude "tmp/" */
-  cfg->exclude_patterns = malloc(2 * sizeof(char*));
-  EXPECT_NOT_NULL(cfg->exclude_patterns);
-  cfg->exclude_patterns[0] = str_dup("*.log");
-  cfg->exclude_patterns[1] = str_dup("tmp/");
-  cfg->exclude_count = 2;
-
-  EXPECT_EQ_STR(cfg->exclude_patterns[0], "*.log");
-  EXPECT_EQ_STR(cfg->exclude_patterns[1], "tmp/");
-  EXPECT_EQ_INT(cfg->exclude_count, 2);
-
-  config_delete(cfg);
-}
-
-void test_client_cli() {
-  test_cli_help();
-  test_cli_archive_flags();
-  test_cli_dry_run();
-  test_cli_delete_flag();
-  test_cli_exclude_patterns();
-}

tests/test_client_cli.h

@@ -1,6 +0,0 @@
-#ifndef TEST_CLIENT_CLI_H
-#define TEST_CLIENT_CLI_H
-
-void test_client_cli();
-
-#endif

tests/test_compression.c

@@ -62,8 +62,8 @@ static void test_chunk_compress_decompress_roundtrip() {
   char* content2 = "chunk compression test file 2 with more data";
   unsigned long long len2 = strlen(content2);
 
-  to_disk(path1, content1, len1, false, false);
+  to_disk(path1, content1, len1);
-  to_disk(path2, content2, len2, false, false);
+  to_disk(path2, content2, len2);
 
   struct stat st1, st2;
   EXPECT_EQ_INT(stat(path1, &st1), 0);

tests/test_config.c

@@ -1,40 +1,14 @@
 #include "test_config.h"
 #include "config.h"
 #include "multiprocessing.h"
-#include "protocol.h"
 #include "queue.h"
 #include "test_utils.h"
 #include "utils.h"
 #include <stdlib.h>
-#include <sys/socket.h>
-#include <string.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-static Config* make_config(const char* version, const char* src, const char* dst, bool save,
-                           bool mt, bool cs, bool comp, bool meta, int clevel, bool sf,
-                           unsigned long long csize) {
-  Config* cfg = config_create();
-  if (!cfg)
-    return NULL;
-  free(cfg->version);
-  cfg->version = str_dup(version);
-  cfg->send_directory = str_dup(src);
-  cfg->receive_root_directory = str_dup(dst);
-  cfg->save_to_disk = save;
-  cfg->use_multithreading = mt;
-  cfg->use_chunk_serialization = cs;
-  cfg->use_compression = comp;
-  cfg->use_metadata = meta;
-  cfg->compression_level = clevel;
-  cfg->use_sendfile = sf;
-  if (csize > 0)
-    cfg->chunk_size = csize;
-  return cfg;
-}
 
 static void test_config_lifecycle() {
-  Config* cfg = make_config("1.0", "/src", "/dst", true, true, false, false, false, 1, false, 0);
+  Config* cfg = config_create(str_dup("1.0"), str_dup("/src"), str_dup("/dst"), true, true, false,
+                              false, false, 1, false, 0);
   EXPECT_NOT_NULL(cfg);
   EXPECT_EQ_STR(cfg->version, "1.0");
   EXPECT_EQ_STR(cfg->send_directory, "/src");
@@ -49,8 +23,8 @@ static void test_config_lifecycle() {
 }
 
 static void test_config_ssh_dest() {
-  Config* cfg =
+  Config* cfg = config_create(str_dup("1.0"), str_dup("/src"), str_dup("user@host:/dst"), true,
-      make_config("1.0", "/src", "user@host:/dst", true, false, false, false, false, 1, false, 0);
+                              false, false, false, false, 1, false, 0);
   EXPECT_NOT_NULL(cfg);
   EXPECT_EQ_INT(cfg->transport, TRANSPORT_TCP);
   EXPECT_NULL(cfg->ssh_destination);
@@ -64,8 +38,8 @@ static void test_config_ssh_dest() {
 }
 
 static void test_config_ssh_dest_local_path() {
-  Config* cfg =
+  Config* cfg = config_create(str_dup("1.0"), str_dup("/src"), str_dup("/local/path"), true, false,
-      make_config("1.0", "/src", "/local/path", true, false, false, false, false, 1, false, 0);
+                              false, false, false, 1, false, 0);
   config_parse_ssh_dest(cfg);
   EXPECT_EQ_INT(cfg->transport, TRANSPORT_TCP);
   EXPECT_NULL(cfg->ssh_destination);
@@ -74,8 +48,8 @@ static void test_config_ssh_dest_local_path() {
 }
 
 static void test_config_ssh_dest_no_user() {
-  Config* cfg =
+  Config* cfg = config_create(str_dup("1.0"), str_dup("/src"), str_dup("host:/remote"), true, false,
-      make_config("1.0", "/src", "host:/remote", true, false, false, false, false, 1, false, 0);
+                              false, false, false, 1, false, 0);
   config_parse_ssh_dest(cfg);
   EXPECT_EQ_INT(cfg->transport, TRANSPORT_SSH);
   EXPECT_EQ_STR(cfg->ssh_destination, "host:/remote");
@@ -84,7 +58,8 @@ static void test_config_ssh_dest_no_user() {
 }
 
 static void test_pipeline_sender_lifecycle() {
-  Config* cfg = make_config("2.0", "/src2", "/dst2", false, false, true, true, false, 1, false, 0);
+  Config* cfg = config_create(str_dup("2.0"), str_dup("/src2"), str_dup("/dst2"), false, false,
+                              true, true, false, 1, false, 0);
   Queue* q1 = queue_create(5, NULL);
   Queue* q2 = queue_create(15, NULL);
 
@@ -100,10 +75,11 @@ static void test_pipeline_sender_lifecycle() {
 }
 
 static void test_pipeline_receiver_lifecycle() {
-  Config* cfg = make_config("3.0", "/src3", "/dst3", true, true, true, true, false, 1, false, 0);
+  Config* cfg = config_create(str_dup("3.0"), str_dup("/src3"), str_dup("/dst3"), true, true, true,
+                              true, false, 1, false, 0);
   Queue* q = queue_create(20, NULL);
 
-  PipelineContextReceiver* pcr = pipeline_context_receiver_create(cfg, q, 42, NULL);
+  PipelineContextReceiver* pcr = pipeline_context_receiver_create(cfg, q, 42);
   EXPECT_NOT_NULL(pcr);
   EXPECT_EQ_STR(pcr->config->version, "3.0");
   EXPECT_EQ_INT(pcr->queue->capacity, 20);
@@ -113,139 +89,6 @@ static void test_pipeline_receiver_lifecycle() {
   pipeline_context_receiver_destroy(pcr);
 }
 
-static void test_config_send_receive() {
-  /* Create a config to send */
-  Config* send_cfg = config_create();
-  EXPECT_NOT_NULL(send_cfg);
-  send_cfg->send_directory = str_dup("/send/src");
-  send_cfg->receive_root_directory = str_dup("/send/dst");
-  send_cfg->save_to_disk = true;
-  send_cfg->use_multithreading = true;
-  send_cfg->use_chunk_serialization = true;
-  send_cfg->use_compression = true;
-  send_cfg->use_metadata = true;
-  send_cfg->compression_level = 5;
-  send_cfg->chunk_size = 1024;
-
-  /* Use socketpair for bidirectional communication */
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    /* Child: use p[0] for both read and write (connected to parent's p[1]) */
-    close(p[1]);
-    io_set_fds(p[0], p[0]);
-    Config* recv_cfg = config_receive(p[0]);
-
-    bool ok = true;
-    if (!recv_cfg)
-      ok = false;
-    else {
-      if (strcmp(recv_cfg->version, PROTOCOL_VERSION) != 0)
-        ok = false;
-      if (strcmp(recv_cfg->send_directory, "/send/src") != 0)
-        ok = false;
-      if (strcmp(recv_cfg->receive_root_directory, "/send/dst") != 0)
-        ok = false;
-      if (!recv_cfg->save_to_disk)
-        ok = false;
-      if (!recv_cfg->use_multithreading)
-        ok = false;
-      if (!recv_cfg->use_chunk_serialization)
-        ok = false;
-      if (recv_cfg->compression_level != 5)
-        ok = false;
-      if (recv_cfg->chunk_size != 1024)
-        ok = false;
-    }
-    config_delete(recv_cfg);
-    close(p[0]);
-    close(p[1]);
-    _exit(ok ? 0 : 1);
-  } else {
-    /* Parent: use p[1] for both read and write (connected to child's p[0]) */
-    close(p[0]);
-    io_set_fds(p[1], p[1]);
-    bool sent = config_send(p[1], send_cfg);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    close(p[0]);
-    close(p[1]);
-
-    config_delete(send_cfg);
-
-    EXPECT_TRUE(sent);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-static void test_config_send_receive_version_mismatch() {
-  /* Create a config with a different protocol version */
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup("0.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
-
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    close(p[1]);
-    io_set_fds(p[0], p[0]);
-    Config* recv = config_receive(p[0]);
-    close(p[0]);
-    _exit(recv == NULL ? 0 : 1);
-  } else {
-    close(p[0]);
-    io_set_fds(p[1], p[1]);
-    bool sent = config_send(p[1], cfg);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    close(p[0]);
-    close(p[1]);
-
-    config_delete(cfg);
-
-    /* config_send receives STATUS_ERROR from config_receive, returns false */
-    EXPECT_FALSE(sent);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-static void test_is_remote_dest() {
-  /* Valid SSH-style destinations */
-  EXPECT_TRUE(is_remote_dest("user@host:/path"));
-  EXPECT_TRUE(is_remote_dest("host:/path"));
-  EXPECT_TRUE(is_remote_dest("user@192.168.1.1:/remote/path"));
-
-  /* Invalid destinations */
-  EXPECT_FALSE(is_remote_dest(NULL));
-  EXPECT_FALSE(is_remote_dest(""));
-  EXPECT_FALSE(is_remote_dest(":"));
-  EXPECT_FALSE(is_remote_dest("/local/path"));
-  EXPECT_FALSE(is_remote_dest("relative/path"));
-  /* C:/windows/path is treated as remote (colon with no preceding slash) */
-  EXPECT_TRUE(is_remote_dest("C:/windows/path"));
-
-  /* Edge cases */
-  EXPECT_FALSE(is_remote_dest("noslash"));
-  EXPECT_FALSE(is_remote_dest("/"));
-  EXPECT_TRUE(is_remote_dest("host:"));
-  EXPECT_TRUE(is_remote_dest("user@host:"));
-}
-
 void test_config() {
   test_config_lifecycle();
   test_config_ssh_dest();
@@ -253,9 +96,4 @@ void test_config() {
   test_config_ssh_dest_no_user();
   test_pipeline_sender_lifecycle();
   test_pipeline_receiver_lifecycle();
-  if (!is_running_under_valgrind()) {
-    test_config_send_receive();
-    test_config_send_receive_version_mismatch();
-  }
-  test_is_remote_dest();
 }

tests/test_delta.c

@@ -35,10 +35,6 @@ static void test_xxhash32_different_data() {
   EXPECT_TRUE(ha != hb);
 }
 
-static void test_xxhash64_different_data() {
-  EXPECT_TRUE(delta_xxhash64("AAAA", 4) != delta_xxhash64("BBBB", 4));
-}
-
 static void test_signature_roundtrip() {
   char old_data[4096];
   for (int i = 0; i < 4096; i++)
@@ -332,7 +328,6 @@ void test_delta() {
   test_adler32_different_data();
   test_xxhash32_basic();
   test_xxhash32_different_data();
-  test_xxhash64_different_data();
   test_signature_roundtrip();
   test_delta_identical_files();
   test_delta_small_edit();

tests/test_file.c

@@ -34,7 +34,7 @@ static void test_file_destroy_normal() {
 
 static void test_file_load_data() {
   const char* content = "Hello Load Test";
-  EXPECT_TRUE(to_disk("test_file_load_data.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_file_load_data.txt", content, strlen(content)));
 
   struct stat st;
   EXPECT_EQ_INT(stat("test_file_load_data.txt", &st), 0);
@@ -69,7 +69,7 @@ static void test_file_save_to_disk() {
   memcpy(f->data->data, content, strlen(content));
   f->data->size = strlen(content);
 
-  EXPECT_TRUE(file_save_to_disk("test_save_tmp", f, NULL));
+  EXPECT_TRUE(file_save_to_disk("test_save_tmp", f));
 
   struct stat st;
   EXPECT_EQ_INT(stat("test_save_tmp/saved_file.txt", &st), 0);
@@ -89,7 +89,7 @@ static void test_file_save_to_disk() {
 
 static void test_to_disk_basic() {
   const char* content = "Basic to_disk test";
-  EXPECT_TRUE(to_disk("test_to_disk_basic.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_to_disk_basic.txt", content, strlen(content)));
 
   struct stat st;
   EXPECT_EQ_INT(stat("test_to_disk_basic.txt", &st), 0);
@@ -108,7 +108,7 @@ static void test_to_disk_basic() {
 
 static void test_to_disk_creates_dirs() {
   const char* content = "Nested dir test";
-  EXPECT_TRUE(to_disk("test_nested_tmp/nested/file.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_nested_tmp/nested/file.txt", content, strlen(content)));
 
   struct stat st;
   EXPECT_EQ_INT(stat("test_nested_tmp/nested/file.txt", &st), 0);
@@ -126,32 +126,9 @@ static void test_to_disk_creates_dirs() {
   rmdir("test_nested_tmp");
 }
 
-static void test_to_disk_does_not_follow_symlink() {
-  const char* outside = "test_to_disk_outside.txt";
-  const char* link = "test_to_disk_link.txt";
-  const char* content = "confined";
-  unlink(outside);
-  unlink(link);
-  EXPECT_TRUE(to_disk(outside, "outside", 7, false, false));
-  EXPECT_EQ_INT(symlink(outside, link), 0);
-  EXPECT_TRUE(to_disk(link, content, strlen(content), false, false));
-  FILE* fp = fopen(outside, "rb");
-  char buf[16] = {0};
-  EXPECT_NOT_NULL(fp);
-  // cppcheck-suppress knownConditionTrueFalse
-  if (!fp)
-    return;
-  size_t read_count = fread(buf, 1, sizeof(buf) - 1, fp);
-  EXPECT_TRUE(read_count <= sizeof(buf) - 1);
-  fclose(fp);
-  EXPECT_EQ_STR(buf, "outside");
-  unlink(outside);
-  unlink(link);
-}
-
 static void test_file_content_to_buffer() {
   const char* content = "Buffer content test";
-  EXPECT_TRUE(to_disk("test_buffer_file.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_buffer_file.txt", content, strlen(content)));
 
   File* f = file_create("test_buffer_file.txt");
   EXPECT_NOT_NULL(f);
@@ -177,12 +154,8 @@ static void test_file_send_receive() {
   memcpy(file->data->data, content, len);
   file->data->size = len;
 
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup(PROTOCOL_VERSION), str_dup("/tmp"), str_dup("/tmp"), false,
-  EXPECT_NOT_NULL(cfg);
+                              false, false, false, false, 0, false, 0);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
 
   int p[2];
   EXPECT_EQ_INT(pipe(p), 0);
@@ -244,6 +217,10 @@ static void test_file_send_no_path() {
   pid_t pid = fork();
   if (pid == 0) {
     close(p[1]);
+    // Read file type indicator
+    int file_type;
+    EXPECT_TRUE(receive_int(p[0], &file_type));
+    EXPECT_EQ_INT(file_type, (int)FILE_TYPE_REGULAR);
     Data* received = receive_data(p[0]);
     close(p[0]);
 
@@ -273,7 +250,7 @@ static void test_file_send_no_path() {
 }
 
 static void test_file_metadata_create() {
-  EXPECT_TRUE(to_disk("test_meta_file.txt", "metadata test", 13, false, false));
+  EXPECT_TRUE(to_disk("test_meta_file.txt", "metadata test", 13));
   struct stat st;
   EXPECT_EQ_INT(stat("test_meta_file.txt", &st), 0);
 
@@ -288,166 +265,6 @@ static void test_file_metadata_create() {
   unlink("test_meta_file.txt");
 }
 
-static void test_file_save_to_disk_path_traversal() {
-  /* Test that path traversal is rejected */
-  File* f = file_create("../etc/passwd");
-  EXPECT_NOT_NULL(f);
-  const char* content = "should not save";
-  f->data->data = malloc(strlen(content));
-  EXPECT_NOT_NULL(f->data->data);
-  memcpy(f->data->data, content, strlen(content));
-  f->data->size = strlen(content);
-
-  /* file_save_to_disk should detect path traversal and return false */
-  EXPECT_FALSE(file_save_to_disk("/tmp", f, NULL));
-
-  file_destroy(f);
-}
-
-static void test_file_save_to_disk_deep_traversal() {
-  File* f = file_create("subdir/../../etc/passwd");
-  EXPECT_NOT_NULL(f);
-  const char* content = "should not save";
-  f->data->data = malloc(strlen(content));
-  EXPECT_NOT_NULL(f->data->data);
-  memcpy(f->data->data, content, strlen(content));
-  f->data->size = strlen(content);
-
-  EXPECT_FALSE(file_save_to_disk("/tmp", f, NULL));
-
-  file_destroy(f);
-}
-
-static void test_file_send_single_calls_compression() {
-  File* file = file_create("test_send_comp.txt");
-  EXPECT_NOT_NULL(file);
-  const char* content = "Hello, Compressed File Transfer!";
-  size_t len = strlen(content);
-  file->data->data = malloc(len);
-  EXPECT_NOT_NULL(file->data->data);
-  memcpy(file->data->data, content, len);
-  file->data->size = len;
-
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
-  cfg->use_compression = true;
-  cfg->compression_level = 3;
-
-  int p[2];
-  EXPECT_EQ_INT(pipe(p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    close(p[1]);
-    File* received = file_receive(cfg, p[0]);
-    close(p[0]);
-
-    bool ok = true;
-    if (!received)
-      ok = false;
-    else {
-      if (strcmp(received->path, "test_send_comp.txt") != 0)
-        ok = false;
-      if (!received->data || received->data->size != len)
-        ok = false;
-      else if (memcmp(received->data->data, content, len) != 0)
-        ok = false;
-    }
-    file_destroy(received);
-    config_delete(cfg);
-    _exit(ok ? 0 : 1);
-  } else {
-    close(p[0]);
-    bool sent = file_send_single_calls(file, p[1], false, 3, true);
-    close(p[1]);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    file_destroy(file);
-    config_delete(cfg);
-
-    EXPECT_TRUE(sent);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-static void test_file_send_single_calls_metadata_and_path() {
-  /* Create a real file on disk so we can have metadata */
-  const char* content = "File with metadata";
-  size_t len = strlen(content);
-  EXPECT_TRUE(to_disk("test_meta_send.txt", content, len, false, false));
-
-  struct stat st;
-  EXPECT_EQ_INT(stat("test_meta_send.txt", &st), 0);
-
-  File* file = file_create("test_meta_send.txt");
-  EXPECT_NOT_NULL(file);
-  file->data->size = len;
-  file->data->data = malloc(len);
-  EXPECT_NOT_NULL(file->data->data);
-  memcpy(file->data->data, content, len);
-  file->metadata = file_metadata_create(&st);
-  EXPECT_NOT_NULL(file->metadata);
-
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
-  cfg->use_metadata = true;
-
-  int p[2];
-  EXPECT_EQ_INT(pipe(p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    close(p[1]);
-    File* received = file_receive(cfg, p[0]);
-    close(p[0]);
-
-    bool ok = true;
-    if (!received)
-      ok = false;
-    else {
-      if (strcmp(received->path, "test_meta_send.txt") != 0)
-        ok = false;
-      if (!received->data || received->data->size != len)
-        ok = false;
-      else if (memcmp(received->data->data, content, len) != 0)
-        ok = false;
-      if (!received->metadata)
-        ok = false;
-    }
-    file_destroy(received);
-    config_delete(cfg);
-    _exit(ok ? 0 : 1);
-  } else {
-    close(p[0]);
-    bool sent = file_send_single_calls(file, p[1], true, 0, true);
-    close(p[1]);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    file_destroy(file);
-    config_delete(cfg);
-    unlink("test_meta_send.txt");
-
-    EXPECT_TRUE(sent);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
 void test_file() {
   test_file_create();
   test_file_destroy_null();
@@ -457,10 +274,7 @@ void test_file() {
   test_file_save_to_disk();
   test_to_disk_basic();
   test_to_disk_creates_dirs();
-  test_to_disk_does_not_follow_symlink();
   test_file_content_to_buffer();
-  test_file_save_to_disk_path_traversal();
-  test_file_save_to_disk_deep_traversal();
   if (!is_running_under_valgrind()) {
     // Fork tests are skipped under valgrind because the parent process runs
     // orders of magnitude slower than the child (parent is instrumented, child
@@ -469,8 +283,6 @@ void test_file() {
     // forked children where inherited allocations are reported as leaks.
     test_file_send_receive();
     test_file_send_no_path();
-    test_file_send_single_calls_compression();
-    test_file_send_single_calls_metadata_and_path();
   }
   test_file_metadata_create();
 }

tests/test_file_sendfile.c

@@ -15,19 +15,16 @@
 static void test_sendfile_basic() {
   const char* content = "Hello from sendfile test!";
   size_t len = strlen(content);
-  EXPECT_TRUE(to_disk("test_sendfile_basic.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_basic.txt", content, len));
 
   File* file = file_create("test_sendfile_basic.txt");
   EXPECT_NOT_NULL(file);
   /* Set the size so file_send_sendfile can report it */
   file->data->size = len;
 
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup(PROTOCOL_VERSION), str_dup("/tmp"), str_dup("/tmp"), false,
+                              false, false, false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
 
   int p[2];
   EXPECT_EQ_INT(pipe(p), 0);
@@ -77,18 +74,15 @@ static void test_sendfile_basic() {
 static void test_sendfile_empty_file() {
   const char* content = "";
   size_t len = 0;
-  EXPECT_TRUE(to_disk("test_sendfile_empty.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_empty.txt", content, len));
 
   File* file = file_create("test_sendfile_empty.txt");
   EXPECT_NOT_NULL(file);
   file->data->size = 0;
 
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup(PROTOCOL_VERSION), str_dup("/tmp"), str_dup("/tmp"), false,
+                              false, false, false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
 
   int p[2];
   EXPECT_EQ_INT(pipe(p), 0);
@@ -156,7 +150,7 @@ static void test_sendfile_missing_file() {
 static void test_sendfile_compression_fallback() {
   const char* content = "Compression fallback content";
   size_t len = strlen(content);
-  EXPECT_TRUE(to_disk("test_sendfile_comp.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_comp.txt", content, len));
 
   struct stat st;
   EXPECT_EQ_INT(stat("test_sendfile_comp.txt", &st), 0);
@@ -167,14 +161,8 @@ static void test_sendfile_compression_fallback() {
   file->data->size = (size_t)st.st_size;
   EXPECT_TRUE(file_load_data(file));
 
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup(PROTOCOL_VERSION), str_dup("/tmp"), str_dup("/tmp"), false,
-  EXPECT_NOT_NULL(cfg);
+                              false, false, true, false, 3, false, 0);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/tmp");
-  cfg->receive_root_directory = str_dup("/tmp");
-  cfg->use_compression = true;
-  cfg->compression_level = 3;
   EXPECT_NOT_NULL(cfg);
 
   int p[2];
@@ -222,7 +210,7 @@ static void test_sendfile_compression_fallback() {
 static void test_sendfile_no_path() {
   const char* content = "No path sendfile test";
   size_t len = strlen(content);
-  EXPECT_TRUE(to_disk("test_sendfile_nopath.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_nopath.txt", content, len));
 
   File* file = file_create("test_sendfile_nopath.txt");
   EXPECT_NOT_NULL(file);
@@ -236,6 +224,10 @@ static void test_sendfile_no_path() {
   pid_t pid = fork();
   if (pid == 0) {
     close(p[1]);
+    /* Read file type indicator */
+    int file_type;
+    EXPECT_TRUE(receive_int(p[0], &file_type));
+    EXPECT_EQ_INT(file_type, (int)FILE_TYPE_REGULAR);
     Data* received = receive_data(p[0]);
     close(p[0]);
 

tests/test_fuzz_smoke.c

@@ -1,180 +0,0 @@
-#include "test_fuzz_smoke.h"
-#include "chunk.h"
-#include "compression.h"
-#include "data.h"
-#include "delta.h"
-#include "metadata.h"
-#include "test_utils.h"
-#include "utils.h"
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-/* Smoke test for chunk_deserialize fuzz target */
-static void test_fuzz_chunk_deserialize() {
-  /* Create a minimal valid chunk to serialize and deserialize */
-  File* file = file_create("fuzz_test.txt");
-  EXPECT_NOT_NULL(file);
-  const char* content = "fuzz data";
-  file->data->data = malloc(strlen(content));
-  EXPECT_NOT_NULL(file->data->data);
-  memcpy(file->data->data, content, strlen(content));
-  file->data->size = strlen(content);
-
-  File* chunk_files[] = {file};
-  Chunk* chunk = chunk_create(chunk_files, 1);
-  EXPECT_NOT_NULL(chunk);
-
-  Data* serialized = chunk_serialize(chunk, true);
-  EXPECT_NOT_NULL(serialized);
-
-  /* Now deserialize (this is what the fuzzer does) */
-  Chunk* deserialized = chunk_deserialize(serialized, true);
-  EXPECT_NOT_NULL(deserialized);
-  EXPECT_EQ_INT(deserialized->element_count, 1);
-
-  chunk_destroy(deserialized);
-  data_destroy(serialized);
-  /* chunk_destroy will also destroy the file added to chunk */
-  chunk_destroy(chunk);
-}
-
-/* Smoke test for compress/decompress fuzz target */
-static void test_fuzz_compress_decompress() {
-  const char* test_data_str = "Hello, this is some test data for compression fuzzing!";
-  size_t len = strlen(test_data_str);
-  void* test_data = malloc(len);
-  EXPECT_NOT_NULL(test_data);
-  memcpy(test_data, test_data_str, len);
-
-  Data* original = data_create(test_data, len);
-  EXPECT_NOT_NULL(original);
-
-  /* Compress at level 3 */
-  Data* compressed = data_compress(original, 3);
-  EXPECT_NOT_NULL(compressed);
-
-  /* Decompress */
-  Data* decompressed = data_decompress(compressed);
-  EXPECT_NOT_NULL(decompressed);
-  EXPECT_EQ_INT((int)decompressed->size, (int)len);
-  EXPECT_EQ_INT(memcmp(decompressed->data, test_data, len), 0);
-
-  data_destroy(decompressed);
-  data_destroy(compressed);
-  data_destroy(original);
-}
-
-/* Smoke test for delta_deserialize fuzz target */
-static void test_fuzz_delta_deserialize() {
-  /* Create two buffers of data */
-  const char* old_data_str = "Hello, World!";
-  const char* new_data_str = "Hello, Delta!";
-  size_t old_len = strlen(old_data_str);
-  size_t new_len = strlen(new_data_str);
-
-  /* Create delta signature from old data */
-  DeltaSignature* sig = delta_signature_create((void*)old_data_str, old_len, 64);
-  EXPECT_NOT_NULL(sig);
-
-  /* Create delta from signature and new data */
-  Delta* delta = delta_compute((void*)new_data_str, new_len, sig, 64);
-  EXPECT_NOT_NULL(delta);
-  EXPECT_EQ_INT((int)delta->new_file_size, (int)new_len);
-
-  /* Serialize the delta */
-  Data* serialized = delta_serialize(delta);
-  EXPECT_NOT_NULL(serialized);
-
-  /* Deserialize (this is what the fuzzer does) */
-  Delta* deserialized = delta_deserialize(serialized);
-  EXPECT_NOT_NULL(deserialized);
-  EXPECT_EQ_INT((int)deserialized->new_file_size, (int)new_len);
-
-  delta_destroy(deserialized);
-  data_destroy(serialized);
-  delta_destroy(delta);
-  delta_signature_destroy(sig);
-}
-
-/* Smoke test for metadata_from_buf fuzz target */
-static void test_fuzz_metadata_from_buf() {
-  /* Create a real file to get metadata from */
-  EXPECT_TRUE(to_disk("fuzz_meta_test.txt", "metadata test", 13, false, false));
-
-  struct stat st;
-  EXPECT_EQ_INT(stat("fuzz_meta_test.txt", &st), 0);
-
-  FileMetadata* meta = file_metadata_create(&st);
-  EXPECT_NOT_NULL(meta);
-  EXPECT_EQ_INT((int)meta->mode, (int)st.st_mode);
-  EXPECT_EQ_INT((int)meta->mtime_sec, (int)st.st_mtime);
-
-  /* Serialize metadata to buffer using the same approach as chunk.c */
-  size_t meta_buf_size = sizeof(int32_t) + FILE_METADATA_WIRE_SIZE;
-  char* meta_buf = malloc(meta_buf_size);
-  EXPECT_NOT_NULL(meta_buf);
-  char* meta_ptr = meta_buf;
-  metadata_to_buf(&meta_ptr, meta);
-  EXPECT_EQ_INT((int)(meta_ptr - meta_buf), (int)meta_buf_size);
-
-  /* Deserialize from buffer (simulates fuzz_metadata_from_buf) */
-  char* buf_copy = meta_buf;
-  FileMetadata* deserialized = metadata_from_buf(&buf_copy);
-  EXPECT_NOT_NULL(deserialized);
-  EXPECT_EQ_INT((int)deserialized->mode, (int)meta->mode);
-  EXPECT_EQ_INT((int)deserialized->mtime_sec, (int)meta->mtime_sec);
-
-  file_metadata_destroy(deserialized);
-  free(meta_buf);
-  file_metadata_destroy(meta);
-  unlink("fuzz_meta_test.txt");
-}
-
-/* Smoke test for delta_signature_deserialize fuzz target */
-static void test_fuzz_delta_signature_deserialize() {
-  const char* data_str = "Test data for signature";
-  size_t len = strlen(data_str);
-
-  DeltaSignature* sig = delta_signature_create((void*)data_str, len, 64);
-  EXPECT_NOT_NULL(sig);
-
-  /* Serialize */
-  Data* serialized = delta_signature_serialize(sig);
-  EXPECT_NOT_NULL(serialized);
-
-  /* Deserialize (simulates what the fuzzer tests) */
-  DeltaSignature* deserialized = delta_signature_deserialize(serialized);
-  EXPECT_NOT_NULL(deserialized);
-  EXPECT_EQ_INT((int)deserialized->block_size, 64);
-
-  delta_signature_destroy(deserialized);
-  data_destroy(serialized);
-  delta_signature_destroy(sig);
-}
-
-/* Smoke test for glob_match fuzz target */
-static void test_fuzz_glob_match() {
-  /* Test various pattern matches */
-  EXPECT_TRUE(glob_match("*.txt", "file.txt"));
-  /* Glob is case-sensitive on this platform */
-  EXPECT_TRUE(glob_match("*.txt", "file.txt"));
-  EXPECT_FALSE(glob_match("*.txt", "file.TXT"));
-  EXPECT_FALSE(glob_match("*.txt", "file.c"));
-  EXPECT_TRUE(glob_match("data?", "data1"));
-  EXPECT_TRUE(glob_match("data?", "dataX"));
-  EXPECT_FALSE(glob_match("data?", "data12"));
-  EXPECT_TRUE(glob_match("src/**/*.c", "src/main.c"));
-  EXPECT_TRUE(glob_match("**/test*.py", "src/tests/test_foo.py"));
-  EXPECT_FALSE(glob_match("*.md", "readme.txt"));
-}
-
-void test_fuzz_smoke() {
-  test_fuzz_chunk_deserialize();
-  test_fuzz_compress_decompress();
-  test_fuzz_delta_deserialize();
-  test_fuzz_metadata_from_buf();
-  test_fuzz_delta_signature_deserialize();
-  test_fuzz_glob_match();
-}

tests/test_fuzz_smoke.h

@@ -1,6 +0,0 @@
-#ifndef TEST_FUZZ_SMOKE_H
-#define TEST_FUZZ_SMOKE_H
-
-void test_fuzz_smoke();
-
-#endif

tests/test_metadata.c

@@ -109,23 +109,10 @@ static void test_metadata_send_null() {
   close(p[1]);
 }
 
-static void test_metadata_rejects_invalid_values() {
-  int p[2];
-  EXPECT_EQ_INT(pipe(p), 0);
-  io_set_fds(p[0], p[1]);
-  int32_t present = 2;
-  EXPECT_TRUE(send_n_data(p[1], &present, sizeof(present)));
-  int ok = 1;
-  EXPECT_NULL(metadata_receive(p[0], &ok));
-  EXPECT_EQ_INT(ok, 0);
-  close(p[0]);
-  close(p[1]);
-}
-
 static void test_file_restore_metadata() {
   const char* path = "temp_meta_restore_test.txt";
   const char* content = "test content";
-  EXPECT_TRUE(to_disk(path, content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk(path, content, strlen(content)));
 
   FileMetadata m;
   m.mode = 0644;
@@ -150,6 +137,5 @@ void test_metadata() {
   test_metadata_from_buf_null();
   test_metadata_send_receive_roundtrip();
   test_metadata_send_null();
-  test_metadata_rejects_invalid_values();
   test_file_restore_metadata();
 }

tests/test_multiprocessing.c

@@ -1,25 +1,16 @@
 #include "test_multiprocessing.h"
 #include "multiprocessing.h"
 #include "config.h"
-#include "protocol.h"
 #include "queue.h"
 #include "utils.h"
 #include "test_utils.h"
-#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
-#include <threads.h>
-#include <sys/wait.h>
-#include <unistd.h>
 
 /* Test pipeline_context_sender_create/destroy with valid arguments */
 static void test_sender_create_destroy() {
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup("1.0"), str_dup("/src"), str_dup("/dst"), false, false, false,
+                              false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup("1.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
 
   Queue* q_scanner = queue_create(5, NULL);
   EXPECT_NOT_NULL(q_scanner);
@@ -41,19 +32,14 @@ static void test_sender_create_destroy() {
 
 /* Test pipeline_context_receiver_create/destroy with valid arguments */
 static void test_receiver_create_destroy() {
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup("2.0"), str_dup("/src"), str_dup("/dst"), true, true, false,
+                              false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup("2.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
-  cfg->save_to_disk = true;
-  cfg->use_multithreading = true;
 
   Queue* q = queue_create(20, NULL);
   EXPECT_NOT_NULL(q);
 
-  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, 42, NULL);
+  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, 42);
   EXPECT_NOT_NULL(ctx);
   EXPECT_EQ_STR(ctx->config->version, "2.0");
   EXPECT_EQ_INT(ctx->queue->capacity, 20);
@@ -65,12 +51,9 @@ static void test_receiver_create_destroy() {
 
 /* Test that create handles various queue capacities */
 static void test_sender_queue_capacities() {
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup("3.0"), str_dup("/src"), str_dup("/dst"), false, false, false,
+                              false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup("3.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
 
   /* Single-element queues */
   Queue* q1 = queue_create(1, NULL);
@@ -82,183 +65,37 @@ static void test_sender_queue_capacities() {
   pipeline_context_sender_destroy(ctx);
 }
 
-/* Invalid queue capacities must not create unusable pipeline queues. */
+/* Test that create handles zero-capacity queues */
 static void test_sender_zero_capacity() {
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup("4.0"), str_dup("/src"), str_dup("/dst"), false, false, false,
+                              false, false, 0, false, 0);
   EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup("4.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
 
-  // cppcheck-suppress constVariablePointer
+  Queue* q1 = queue_create(0, NULL);
-  Queue* const q1 = queue_create(0, NULL);
+  Queue* q2 = queue_create(0, NULL);
-  // cppcheck-suppress constVariablePointer
+  PipelineContextSender* ctx = pipeline_context_sender_create(cfg, q1, q2);
-  Queue* const q2 = queue_create(0, NULL);
+  EXPECT_NOT_NULL(ctx);
-  EXPECT_NULL(q1);
+  EXPECT_EQ_INT(ctx->queue_scanner->capacity, 0);
-  EXPECT_NULL(q2);
+  EXPECT_EQ_INT(ctx->queue_loader->capacity, 0);
-  config_delete(cfg);
+  pipeline_context_sender_destroy(ctx);
 }
 
 /* Test receiver with zero file_descriptor */
 static void test_receiver_fd_zero() {
-  Config* cfg = config_create();
+  Config* cfg = config_create(str_dup("5.0"), str_dup("/src"), str_dup("/dst"), false, false, false,
-  EXPECT_NOT_NULL(cfg);
+                              false, false, 0, false, 0);
-  free(cfg->version);
-  cfg->version = str_dup("5.0");
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/dst");
   Queue* q = queue_create(5, NULL);
-  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, 0, NULL);
+  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, 0);
   EXPECT_NOT_NULL(ctx);
   EXPECT_EQ_INT(ctx->file_descriptor, 0);
   EXPECT_FALSE(ctx->receiver_done);
   pipeline_context_receiver_destroy(ctx);
 }
 
-/* Test that receive_thread completes cleanly when sent FINISHED immediately */
-static void test_receive_thread_finished() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-  cfg->save_to_disk = true;
-
-  int p[2];
-  EXPECT_EQ_INT(pipe(p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    /* Child: run receive_thread */
-    close(p[1]);
-
-    Queue* q = queue_create(5, file_destroy);
-    EXPECT_NOT_NULL(q);
-    PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, p[0], NULL);
-    EXPECT_NOT_NULL(ctx);
-
-    int ret = receive_thread(ctx);
-
-    pipeline_context_receiver_destroy(ctx);
-    close(p[0]);
-    _exit(ret == thrd_success ? 0 : 1);
-  } else {
-    /* Parent: send STATUS_FINISHED then STATUS_MANIFEST */
-    close(p[0]);
-
-    /* Send a STATUS_FINISHED to make receive_thread exit cleanly.
-     * receive_thread reads status, sees FINISHED, then exits loop.
-     * After the loop it expects STATUS_MANIFEST check, but we sent
-     * FINISHED so it will just return thrd_success. */
-    send_status(p[1], STATUS_FINISHED);
-
-    close(p[1]);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    /* Parent must free its own copies of config (child has separate copies) */
-    config_delete(cfg);
-
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-/* A malformed terminal status must wake a writer waiting on an empty queue. */
-static void test_receive_thread_failure_wakes_writer() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-
-  int p[2];
-  EXPECT_EQ_INT(pipe(p), 0);
-  Queue* q = queue_create(1, file_destroy);
-  EXPECT_NOT_NULL(q);
-  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, p[0], NULL);
-  EXPECT_NOT_NULL(ctx);
-
-  thrd_t receiver;
-  thrd_t writer;
-  EXPECT_EQ_INT(thrd_create(&writer, write_thread, ctx), thrd_success);
-  EXPECT_EQ_INT(thrd_create(&receiver, receive_thread, ctx), thrd_success);
-  EXPECT_TRUE(send_status(p[1], STATUS_OK));
-  close(p[1]);
-
-  int receiver_result;
-  int writer_result;
-  EXPECT_EQ_INT(thrd_join(receiver, &receiver_result), thrd_success);
-  EXPECT_EQ_INT(thrd_join(writer, &writer_result), thrd_success);
-  EXPECT_EQ_INT(receiver_result, thrd_error);
-  EXPECT_EQ_INT(writer_result, thrd_success);
-  EXPECT_TRUE(ctx->receiver_done);
-
-  close(p[0]);
-  pipeline_context_receiver_destroy(ctx);
-}
-
-/* Test that write_thread completes cleanly when queue signals done */
-static void test_write_thread_done() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-  cfg->save_to_disk = false;
-
-  Queue* q = queue_create(5, file_destroy);
-  EXPECT_NOT_NULL(q);
-
-  PipelineContextReceiver* ctx = pipeline_context_receiver_create(cfg, q, 0, NULL);
-  EXPECT_NOT_NULL(ctx);
-
-  /* Mark receiver as done BEFORE starting the thread so it exits immediately */
-  ctx->receiver_done = true;
-
-  thrd_t writer;
-  int ret = thrd_create(&writer, write_thread, ctx);
-  EXPECT_EQ_INT(ret, thrd_success);
-
-  int result;
-  thrd_join(writer, &result);
-  EXPECT_EQ_INT(result, thrd_success);
-
-  /* Don't call pipeline_context_receiver_destroy because it frees ctx
-   * and write_thread doesn't destroy ctx. Actually looking at the code:
-   * write_thread reads context fields but doesn't free anything.
-   * The caller is responsible for cleanup. So we need to clean up.
-   * But wait - write_thread takes ownership? Let me check...
-   * No, write_thread just processes and returns. The caller frees.
-   *
-   * However, pipeline_context_receiver_destroy will call config_delete
-   * and queue_destroy which would double-free since we created them
-   * in this test. Let me just free the context directly. */
-  mtx_destroy(&ctx->mutex);
-  cnd_destroy(&ctx->condition_not_full);
-  cnd_destroy(&ctx->condition_not_empty);
-  free(ctx);
-
-  /* q and cfg still need cleanup */
-  queue_destroy(q);
-  config_delete(cfg);
-}
-
 void test_multiprocessing() {
   test_sender_create_destroy();
   test_receiver_create_destroy();
   test_sender_queue_capacities();
   test_sender_zero_capacity();
   test_receiver_fd_zero();
-  if (!is_running_under_valgrind()) {
-    test_receive_thread_finished();
-    test_receive_thread_failure_wakes_writer();
-  }
-  test_write_thread_done();
 }

tests/test_property.c

@@ -84,7 +84,7 @@ static void test_property_chunk_roundtrip() {
     for (int i = 0; i < content_len; i++)
       content[i] = (char)(rand() % 256);
 
-    to_disk(path, content, content_len, false, false);
+    to_disk(path, content, content_len);
 
     struct stat st;
     stat(path, &st);

tests/test_protocol.c

@@ -128,9 +128,8 @@ static void test_send_receive_status() {
   io_set_fds(p[0], p[1]);
   io_set_bwlimit(0);
 
-  Status statuses[] = {STATUS_OK,        STATUS_ERROR, STATUS_FINISHED,        STATUS_NEXT,
+  Status statuses[] = {STATUS_OK,    STATUS_ERROR, STATUS_FINISHED,        STATUS_NEXT,
-                       STATUS_CHUNK,     STATUS_CHECK, STATUS_DELTA_SIGNATURE, STATUS_DELTA_DATA,
+                       STATUS_CHUNK, STATUS_CHECK, STATUS_DELTA_SIGNATURE, STATUS_DELTA_DATA};
-                       STATUS_KEEPALIVE, STATUS_ABORT, STATUS_CHECK_BATCH};
   int count = sizeof(statuses) / sizeof(statuses[0]);
 
   for (int i = 0; i < count; i++) {
@@ -170,6 +169,24 @@ static void test_receive_str_truncated() {
   close(p[0]);
 }
 
+static void test_receive_str_oversized() {
+  int p[2];
+  EXPECT_EQ_INT(pipe(p), 0);
+  io_set_fds(p[0], p[1]);
+  io_set_bwlimit(0);
+
+  /* Send a size exceeding MAX_STRING_SIZE */
+  size_t huge = MAX_STRING_SIZE + 1;
+  EXPECT_TRUE(send_n_data(0, &huge, sizeof(size_t)));
+
+  /* cppcheck-suppress constVariablePointer */
+  char* received = receive_str(0);
+  EXPECT_NULL(received);
+
+  close(p[0]);
+  close(p[1]);
+}
+
 void test_protocol() {
   test_send_receive_n_data();
   test_send_receive_n_data_zero();
@@ -180,4 +197,5 @@ void test_protocol() {
   test_send_receive_status();
   test_receive_n_data_truncated();
   test_receive_str_truncated();
+  test_receive_str_oversized();
 }

tests/test_queue.c

@@ -56,11 +56,6 @@ static void test_queue_basic() {
   queue_destroy(q);
 }
 
-static void test_queue_rejects_invalid_capacity() {
-  EXPECT_NULL(queue_create(0, NULL));
-  EXPECT_NULL(queue_create(-1, NULL));
-}
-
 static void test_queue_resize() {
   Queue* q = queue_create(3, NULL);
   EXPECT_NOT_NULL(q);
@@ -204,7 +199,6 @@ static void test_queue_multithreaded() {
 
 void test_queue() {
   test_queue_basic();
-  test_queue_rejects_invalid_capacity();
   test_queue_resize();
   test_queue_destroyer();
   test_queue_multithreaded();

tests/test_robustness.c

@@ -13,7 +13,7 @@
 static void test_chunk_deserialize_truncated() {
   char* path = "test_rob_trunc.txt";
   char* content = "hello";
-  to_disk(path, content, strlen(content), false, false);
+  to_disk(path, content, strlen(content));
 
   struct stat st;
   stat(path, &st);

tests/test_scanner.c

@@ -7,7 +7,7 @@
 #include <unistd.h>
 
 static void create_test_file(const char* path, const char* content) {
-  (void)to_disk(path, content, strlen(content), false, false);
+  (void)to_disk(path, content, strlen(content));
 }
 
 static void test_scanner_single_file() {
@@ -15,11 +15,11 @@ static void test_scanner_single_file() {
   const char* file1 = "test_scan_dir_single/file1.txt";
   const char* content1 = "hello scanner";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(file1, content1);
 
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -43,12 +43,12 @@ static void test_scanner_multiple_files() {
   const char* content1 = "alpha";
   const char* content2 = "beta";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(file1, content1);
   create_test_file(file2, content2);
 
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   const Chunk* chunk = directory_scanner_next(scanner);
@@ -82,13 +82,13 @@ static void test_scanner_subdirectory() {
   const char* sub_file = "test_scan_sub/sub/sub_file.txt";
   const char* content = "nested content";
 
-  EXPECT_EQ_INT(mkdir(root, 0755), 0);
+  mkdir(root, 0755);
-  EXPECT_EQ_INT(mkdir(sub, 0755), 0);
+  mkdir(sub, 0755);
   create_test_file(root_file, content);
   create_test_file(sub_file, content);
 
-  DirectoryScanner* scanner = directory_scanner_create((char*)root, false, 0, NULL, 0, NULL, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, 0, false, false, false, false, false);
+      directory_scanner_create((char*)root, false, 0, NULL, 0, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   int total_files = 0;
@@ -109,10 +109,10 @@ static void test_scanner_subdirectory() {
 static void test_scanner_empty_directory() {
   const char* dir = "test_scan_empty";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
 
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   const Chunk* chunk = directory_scanner_next(scanner);
@@ -130,13 +130,13 @@ static void test_scanner_exclude_pattern() {
   const char* f_tmp = "test_scan_excl/remove.tmp";
   const char* content = "data";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(f_txt, content);
   create_test_file(f_tmp, content);
 
   char* exclude[] = {"*.tmp"};
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, exclude, 1, NULL, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, 0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, exclude, 1, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -154,6 +154,8 @@ static void test_scanner_exclude_pattern() {
 }
 
 static void test_scanner_exclude_subdirectory() {
+  /* Exclude patterns match filenames only (via entry->d_name).
+   * Files inside subdirectories are also matched by filename. */
   const char* root = "test_scan_excl_sub";
   const char* sub = "test_scan_excl_sub/sub";
   const char* root_txt = "test_scan_excl_sub/root.txt";
@@ -161,15 +163,16 @@ static void test_scanner_exclude_subdirectory() {
   const char* sub_tmp = "test_scan_excl_sub/sub/temp.tmp";
   const char* content = "data";
 
-  EXPECT_EQ_INT(mkdir(root, 0755), 0);
+  mkdir(root, 0755);
-  EXPECT_EQ_INT(mkdir(sub, 0755), 0);
+  mkdir(sub, 0755);
   create_test_file(root_txt, content);
   create_test_file(sub_txt, content);
   create_test_file(sub_tmp, content);
 
+  /* Exclude *.tmp — should exclude sub/temp.tmp but keep root.txt and sub/data.txt */
   char* exclude[] = {"*.tmp"};
-  DirectoryScanner* scanner = directory_scanner_create((char*)root, false, 0, exclude, 1, NULL, 0,
+  DirectoryScanner* scanner =
-                                                       0, 0, 0, false, false, false, false, false);
+      directory_scanner_create((char*)root, false, 0, exclude, 1, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   int total = 0;
@@ -177,6 +180,7 @@ static void test_scanner_exclude_subdirectory() {
   while ((chunk = directory_scanner_next(scanner)) != NULL) {
     total += chunk->element_count;
     for (int i = 0; i < chunk->element_count; i++) {
+      /* No path should end in .tmp */
       size_t len = strlen(chunk->items[i]->path);
       EXPECT_TRUE(len < 4 || strcmp(chunk->items[i]->path + len - 4, ".tmp") != 0);
     }
@@ -193,21 +197,26 @@ static void test_scanner_exclude_subdirectory() {
 }
 
 static void test_scanner_include_and_exclude() {
+  /* In the scanner, exclude is checked first and takes precedence.
+   * Include patterns act as an additional filter: if include_count > 0,
+   * the file must match one of the include patterns (after not being excluded).
+   * This test uses non-overlapping exclude and include patterns. */
   const char* dir = "test_scan_inc_exc";
   const char* f_txt = "test_scan_inc_exc/a.txt";
   const char* f_log = "test_scan_inc_exc/b.log";
   const char* f_bak = "test_scan_inc_exc/c.bak";
   const char* content = "filter";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(f_txt, content);
   create_test_file(f_log, content);
   create_test_file(f_bak, content);
 
+  /* Exclude *.bak. Include *.txt and *.log. */
   char* exclude[] = {"*.bak"};
   char* include[] = {"*.txt", "*.log"};
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, exclude, 1, include, 2,
+  DirectoryScanner* scanner =
-                                                       0, 0, 0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, exclude, 1, include, 2, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -221,6 +230,7 @@ static void test_scanner_include_and_exclude() {
     if (strstr(chunk->items[i]->path, "b.log"))
       found_log = 1;
   }
+  /* a.txt included by *.txt, b.log included by *.log, c.bak excluded by *.bak */
   EXPECT_TRUE(found_txt);
   EXPECT_TRUE(found_log);
 
@@ -238,13 +248,16 @@ static void test_scanner_max_size() {
   const char* dir = "test_scan_max";
   const char* small = "test_scan_max/small.txt";
   const char* large = "test_scan_max/large.txt";
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  create_test_file(small, "tiny");
+  create_test_file(large, "this_content_is_longer_than_ten_chars");
+
+  mkdir(dir, 0755);
   create_test_file(small, "tiny");
   create_test_file(large, "this_content_is_longer_than_ten_chars");
 
   /* max_size = 10 — only files <= 10 bytes */
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 10,
+  DirectoryScanner* scanner =
-                                                       0, 0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 10, 0);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -266,13 +279,13 @@ static void test_scanner_min_size() {
   const char* empty_f = "test_scan_min/empty.txt";
   const char* data_f = "test_scan_min/data.txt";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(empty_f, "");
   create_test_file(data_f, "some content here");
 
   /* min_size = 1 — only files >= 1 byte */
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 1,
+  DirectoryScanner* scanner =
-                                                       0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 1);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -295,14 +308,14 @@ static void test_scanner_size_range() {
   const char* medium = "test_scan_range/med.txt";
   const char* huge = "test_scan_range/huge.txt";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(tiny, "ab");
   create_test_file(medium, "hello world");
   create_test_file(huge, "this is a much larger file for testing size filters");
 
   /* Only files between 3 and 20 bytes */
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 20,
+  DirectoryScanner* scanner =
-                                                       3, 0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 20, 3);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -328,7 +341,7 @@ static void test_scanner_mixed_patterns() {
   const char* c_txt = "test_scan_mixed/c.txt"; /* size ~= 5  */
   const char* d_bak = "test_scan_mixed/d.bak"; /* size ~= 42 */
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(a_txt, "aaaaa");
   create_test_file(b_bin, "bbbbbbbbbbbbb");
   create_test_file(c_txt, "ccccc");
@@ -337,8 +350,8 @@ static void test_scanner_mixed_patterns() {
   /* Exclude *.bak, include *.txt, min_size=3, max_size=10 */
   char* exclude[] = {"*.bak"};
   char* include[] = {"*.txt"};
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, exclude, 1, include, 1,
+  DirectoryScanner* scanner =
-                                                       10, 3, 0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, exclude, 1, include, 1, 10, 3);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -364,12 +377,12 @@ static void test_scanner_no_patterns() {
   const char* f1 = "test_scan_none/f1.txt";
   const char* f2 = "test_scan_none/f2.txt";
 
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
+  mkdir(dir, 0755);
   create_test_file(f1, "first");
   create_test_file(f2, "second");
 
-  DirectoryScanner* scanner = directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0,
+  DirectoryScanner* scanner =
-                                                       0, false, false, false, false, false);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);

tests/test_server.c

@@ -1,196 +0,0 @@
-#include "test_server.h"
-#include "config.h"
-#include "file.h"
-#include "protocol.h"
-#include "test_utils.h"
-#include "utils.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/socket.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-/* Include server.c but rename main to avoid conflict with test runner's main */
-#define main server_main_
-#define FASTSYNC_SERVER_AS_LIB
-#include "server.c"
-#undef main
-
-/* Test receive_files with immediate FINISHED status */
-static void test_receive_files_finished() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    /* Child: use p[0] for both read and write */
-    close(p[1]);
-    io_set_fds(p[0], p[0]);
-    int ret = receive_files(cfg, p[0]);
-    close(p[0]);
-    config_delete(cfg);
-    _exit(ret == 0 ? 0 : 1);
-  } else {
-    /* Parent: use p[1] for both read and write */
-    close(p[0]);
-    io_set_fds(p[1], p[1]);
-    send_status(p[1], STATUS_FINISHED);
-    /* receive_files expects an initial status, then loops.
-     * If we send STATUS_FINISHED first, it won't enter the loop body
-     * (status == STATUS_FINISHED doesn't match any case).
-     * After the loop, it checks if status == STATUS_FINISHED -> yes.
-     * Then sends STATUS_OK and returns 0. */
-    /* receive_files will send STATUS_OK back, read it */
-    Status resp;
-    receive_status(p[1], &resp);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    close(p[1]);
-
-    config_delete(cfg);
-
-    EXPECT_EQ_INT(resp, STATUS_OK);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-/* Test receive_files with STATUS_NEXT + file data */
-static void test_receive_files_single_file() {
-  const char* content = "Hello from server test!";
-  size_t len = strlen(content);
-
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    /* Child: use p[0] for both read and write */
-    close(p[1]);
-    io_set_fds(p[0], p[0]);
-    int ret = receive_files(cfg, p[0]);
-    close(p[0]);
-    config_delete(cfg);
-    _exit(ret == 0 ? 0 : 1);
-  } else {
-    /* Parent: use p[1] for both read and write */
-    close(p[0]);
-    io_set_fds(p[1], p[1]);
-
-    /* Send initial status = STATUS_NEXT */
-    send_status(p[1], STATUS_NEXT);
-
-    /* Now send the file data */
-    File* file = file_create("test_server_file.txt");
-    EXPECT_NOT_NULL(file);
-    file->data->data = malloc(len);
-    EXPECT_NOT_NULL(file->data->data);
-    memcpy(file->data->data, content, len);
-    file->data->size = len;
-
-    /* Send path, then data (no metadata since config has use_metadata=false) */
-    send_str(p[1], file->path);
-    send_data(p[1], file->data);
-
-    file_destroy(file);
-
-    /* Now send FINISHED to complete */
-    send_status(p[1], STATUS_FINISHED);
-    Status resp;
-    receive_status(p[1], &resp);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    close(p[1]);
-
-    config_delete(cfg);
-
-    EXPECT_EQ_INT(resp, STATUS_OK);
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-/* Test receive_files with STATUS_ABORT */
-static void test_receive_files_abort() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  free(cfg->version);
-  cfg->version = str_dup(PROTOCOL_VERSION);
-  cfg->send_directory = str_dup("/src");
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  io_set_bwlimit(0);
-
-  pid_t pid = fork();
-  if (pid == 0) {
-    close(p[1]);
-    io_set_fds(p[0], p[0]);
-    int ret = receive_files(cfg, p[0]);
-    close(p[0]);
-    config_delete(cfg);
-    /* Should return -1 on abort */
-    _exit(ret == -1 ? 0 : 1);
-  } else {
-    close(p[0]);
-    io_set_fds(p[1], p[1]);
-    /* Send STATUS_ABORT */
-    send_status(p[1], STATUS_ABORT);
-
-    int status;
-    waitpid(pid, &status, 0);
-
-    close(p[1]);
-
-    config_delete(cfg);
-
-    EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-  }
-}
-
-static void test_receive_manifest_rejects_traversal() {
-  Config* cfg = config_create();
-  EXPECT_NOT_NULL(cfg);
-  cfg->receive_root_directory = str_dup("/tmp/dst");
-  int p[2];
-  EXPECT_EQ_INT(socketpair(AF_UNIX, SOCK_STREAM, 0, p), 0);
-  io_set_fds(p[0], p[1]);
-  EXPECT_TRUE(send_int(p[1], 1));
-  EXPECT_TRUE(send_str(p[1], "../outside"));
-  EXPECT_EQ_INT(receive_manifest(p[0], cfg, NULL), -1);
-  close(p[0]);
-  close(p[1]);
-  config_delete(cfg);
-}
-
-void test_server() {
-  if (!is_running_under_valgrind()) {
-    test_receive_files_finished();
-    test_receive_files_single_file();
-    test_receive_files_abort();
-    test_receive_manifest_rejects_traversal();
-  }
-}

tests/test_server.h

@@ -1,6 +0,0 @@
-#ifndef TEST_SERVER_H
-#define TEST_SERVER_H
-
-void test_server();
-
-#endif

tests/test_transport_ssh.c

@@ -1,16 +1,22 @@
 #include "test_transport_ssh.h"
-#include "test_utils.h"
 #include "transport_ssh.h"
+#include "test_utils.h"
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
 
-static void test_ssh_connect_invalid_dest_no_colon() {
+/* Test client_connect_ssh with invalid destination (missing colon) */
+static void test_ssh_connect_invalid_dest() {
+  /* Missing colon — parse_remote_dest should fail and return NULL */
   /* cppcheck-suppress constVariablePointer */
-  Client* client = client_connect_ssh("invalid-destination-no-colon", 22, NULL);
+  Client* client = client_connect_ssh("invalid-destination-no-colon", 22);
   EXPECT_NULL(client);
 }
 
-static void test_ssh_connect_invalid_dest_empty() {
+/* Test client_connect_ssh with empty destination */
+static void test_ssh_connect_empty_dest() {
   /* cppcheck-suppress constVariablePointer */
-  Client* client = client_connect_ssh("", 22, NULL);
+  Client* client = client_connect_ssh("", 22);
   EXPECT_NULL(client);
 }
 
@@ -18,7 +24,7 @@ static void test_ssh_connect_invalid_dest_empty() {
  * parse_remote_dest succeeds, ssh is exec'd and fails, but the function
  * creates a Client that must be cleaned up. */
 static void test_ssh_connect_malformed() {
-  Client* client = client_connect_ssh(":", 22, NULL);
+  Client* client = client_connect_ssh(":", 22);
   /* ssh binary exists, so exec succeeds; the function returns a Client.
    * We just verify it doesn't crash and clean up properly. */
   if (client != NULL) {
@@ -31,7 +37,7 @@ static void test_ssh_connect_malformed() {
 /* Test client_connect_ssh with valid format but unreachable host.
  * The function launches ssh which will fail to connect, returns a Client. */
 static void test_ssh_connect_unreachable() {
-  Client* client = client_connect_ssh("nonexistent.invalid:/remote/path", 22, NULL);
+  Client* client = client_connect_ssh("nonexistent.invalid:/remote/path", 22);
   if (client != NULL) {
     client_disconnect(client);
     client_delete(client);
@@ -40,8 +46,8 @@ static void test_ssh_connect_unreachable() {
 }
 
 void test_transport_ssh() {
-  test_ssh_connect_invalid_dest_no_colon();
+  test_ssh_connect_invalid_dest();
-  test_ssh_connect_invalid_dest_empty();
+  test_ssh_connect_empty_dest();
   test_ssh_connect_malformed();
   test_ssh_connect_unreachable();
 }

tests/test_transport_tcp.c

@@ -1,102 +1,89 @@
 #include "test_transport_tcp.h"
-#include "protocol.h"
-#include "test_utils.h"
 #include "transport_tcp.h"
-#include <string.h>
+#include "test_utils.h"
+#include <stdlib.h>
 #include <unistd.h>
 
-static void test_server_create_ephemeral() {
+/* Test client_create and client_delete lifecycle */
-  Server* s = server_create(0);
+static void test_client_create_delete() {
-  EXPECT_NOT_NULL(s);
+  Client* client = client_create();
-  EXPECT_TRUE(s->file_descriptor >= 0);
+  EXPECT_NOT_NULL(client);
-  EXPECT_EQ_INT(s->address.sin_family, AF_INET);
+  EXPECT_EQ_INT(client->file_descriptor, -1);
-  server_delete(&s);
+  EXPECT_TRUE(client->address.ss_family == AF_UNSPEC);
-  EXPECT_NULL(s);
+  EXPECT_EQ_INT(client->ssh_child_pid, -1);
+  EXPECT_NULL(client->ssl);
+  EXPECT_NULL(client->ssl_ctx);
+
+  /* Delete should clean up without error */
+  client_delete(client);
 }
 
-static void test_server_delete_null() {
+/* Test client_delete with NULL (safety) */
+static void test_client_delete_null() {
+  client_delete(NULL);
+  EXPECT_TRUE(true);
+}
+
+/* Test server_create and server_delete lifecycle */
+static void test_server_create_delete() {
+  /* Use port 0 to let the OS assign a port */
+  Server* server = server_create(0);
+  EXPECT_NOT_NULL(server);
+  EXPECT_TRUE(server->file_descriptor >= 0);
+  EXPECT_TRUE(server->address.ss_family == AF_INET || server->address.ss_family == AF_INET6);
+  EXPECT_NULL(server->ssl_ctx);
+
+  /* Clean up */
+  server_delete(&server);
+  EXPECT_NULL(server);
+}
+
+/* Test server_delete with NULL pointer */
+static void test_server_delete_null_ptr() {
+  server_delete(NULL);
+  EXPECT_TRUE(true);
+}
+
+/* Test server_delete with NULL server */
+static void test_server_delete_null_server() {
   Server* s = NULL;
   server_delete(&s);
   EXPECT_NULL(s);
 }
 
-static void test_client_create() {
+/* Test client_create can be called multiple times */
-  Client* c = client_create();
+static void test_client_create_multiple() {
-  EXPECT_NOT_NULL(c);
+  Client* c1 = client_create();
-  EXPECT_TRUE(c->file_descriptor == -1);
+  Client* c2 = client_create();
-  EXPECT_EQ_INT(c->address.ss_family, 0);
+  EXPECT_NOT_NULL(c1);
-  EXPECT_EQ_INT(c->ssh_child_pid, -1);
+  EXPECT_NOT_NULL(c2);
-  EXPECT_NULL(c->ssl);
+  EXPECT_EQ_INT(c1->file_descriptor, -1);
-  EXPECT_NULL(c->ssl_ctx);
+  EXPECT_EQ_INT(c2->file_descriptor, -1);
-  client_disconnect(c);
+
-  client_delete(c);
+  client_delete(c1);
+  client_delete(c2);
 }
 
-static void test_client_delete_null() {
+/* Test client_disconnect on a fresh client (should close socket) */
-  Client* c = NULL;
+static void test_client_disconnect_fresh() {
-  client_delete(c);
+  Client* client = client_create();
-}
+  EXPECT_NOT_NULL(client);
 
-/* Test tcp_set_timeouts with valid values */
+  /* Disconnect should close the file descriptor */
-static void test_tcp_set_timeouts() {
+  client_disconnect(client);
-  /* Just verify the function doesn't crash with edge cases */
+  /* The fd should now be invalid */
-  tcp_set_timeouts(0, 0);   /* zero means "don't change" */
+  /* Verify by trying to use close() on it - should fail */
-  tcp_set_timeouts(60, 20); /* normal values */
+  EXPECT_EQ_INT(close(client->file_descriptor), -1);
-  tcp_set_timeouts(-1, -1); /* negative means "don't change" */
-  /* If we got here without crashing, the test passes */
-  EXPECT_TRUE(true);
-}
 
-/* Test client_connect with an invalid host (should fail gracefully) */
+  client_delete(client);
-static void test_client_connect_invalid_host() {
-  Client* c = client_create();
-  EXPECT_NOT_NULL(c);
-
-  /* Use a non-routable IP that will fail connect quickly */
-  bool ok = client_connect(c, "10.255.255.1", 9999);
-  EXPECT_FALSE(ok);
-
-  client_disconnect(c);
-  client_delete(c);
-}
-
-/* Test server_create with a specific port */
-static void test_server_create_specific_port() {
-  /* Port 0 = ephemeral, but try 0 and verify bind works */
-  Server* s = server_create(0);
-  EXPECT_NOT_NULL(s);
-  EXPECT_TRUE(s->file_descriptor >= 0);
-  server_delete(&s);
-  EXPECT_NULL(s);
-}
-
-/* Test server_create with invalid port (0 is valid for ephemeral) */
-static void test_server_delete_double() {
-  Server* s = server_create(0);
-  EXPECT_NOT_NULL(s);
-  server_delete(&s);
-  EXPECT_NULL(s);
-  /* Deleting again should be safe - pointer is already NULL */
-  server_delete(&s);
-  EXPECT_NULL(s);
-}
-
-/* Test client_disconnect followed by client_delete */
-static void test_client_disconnect_delete() {
-  Client* c = client_create();
-  EXPECT_NOT_NULL(c);
-  client_disconnect(c);
-  client_delete(c);
 }
 
 void test_transport_tcp() {
-  test_server_create_ephemeral();
+  test_client_create_delete();
-  test_server_delete_null();
-  test_client_create();
   test_client_delete_null();
-  test_tcp_set_timeouts();
+  test_server_create_delete();
-  test_client_connect_invalid_host();
+  test_server_delete_null_ptr();
-  test_server_create_specific_port();
+  test_server_delete_null_server();
-  test_server_delete_double();
+  test_client_create_multiple();
-  test_client_disconnect_delete();
+  test_client_disconnect_fresh();
 }

tests/test_transport_tls.c

@@ -1,61 +1,81 @@
 #include "test_transport_tls.h"
-#include "protocol.h"
-#include "test_utils.h"
-#include "transport_tcp.h"
 #include "transport_tls.h"
-#include <string.h>
+#include "transport_tcp.h"
+#include "test_utils.h"
+#include <stdlib.h>
 #include <unistd.h>
 
+/* Test tls_global_init succeeds */
 static void test_tls_global_init() {
   bool ok = tls_global_init();
   EXPECT_TRUE(ok);
 }
 
-static void test_server_create_tls_without_certs() {
+/* Test tls_global_init can be called multiple times */
-  Server* s = server_create(0);
+static void test_tls_global_init_twice() {
-  EXPECT_NOT_NULL(s);
+  bool ok1 = tls_global_init();
-  bool ok = server_create_tls(s, NULL, NULL, NULL);
+  bool ok2 = tls_global_init();
-  EXPECT_TRUE(ok);
+  EXPECT_TRUE(ok1);
-  EXPECT_NOT_NULL(s->ssl_ctx);
+  EXPECT_TRUE(ok2);
-  server_delete(&s);
-  EXPECT_NULL(s);
 }
 
-/* Test client_connect_tls with no server listening (should fail gracefully) */
+/* Test client_connect_tls with bad certificate path.
-static void test_client_connect_tls_fail() {
+ * The function will create a socket, try to connect to localhost,
-  /* Create a client to localhost on a high port with no server */
+ * fail to connect (since nothing is listening), and return false.
-  Client* c = client_create();
+ * We don't need a server to verify the error path. */
-  EXPECT_NOT_NULL(c);
+static void test_tls_connect_bad_cert() {
+  /* First, init TLS globally */
+  tls_global_init();
 
-  /* connect to localhost:1 (no server) - should fail as connect() fails first */
+  Client* client = client_create();
-  bool ok = client_connect_tls(c, "127.0.0.1", 1, NULL, NULL, NULL);
+  EXPECT_NOT_NULL(client);
+
+  /* Attempt to connect to a non-existent server with bad cert paths.
+   * client_connect_tls will try to connect first, fail, and return false.
+   * Note: we use an invalid host to ensure connection failure,
+   * which exercises the error path before cert loading. */
+  bool ok = client_connect_tls(client, "127.0.0.1", 1, "/nonexistent/cert.pem",
+                               "/nonexistent/key.pem", "/nonexistent/ca.pem");
   EXPECT_FALSE(ok);
 
-  /* Note: client_connect_tls internally calls connect() which sets up the socket.
+  client_delete(client);
-   * On failure it returns false but does NOT close the socket - we need to
-   * disconnect/delete the client. The socket fd may be in an undefined state
-   * after a failed connect, so we just call client_delete which closes it. */
-  client_disconnect(c);
-  client_delete(c);
 }
 
-/* Test server_create_tls with missing cert file paths (should still create ctx without certs) */
+/* Test client_connect_tls with NULL cert paths (should still attempt connection).
-static void test_server_create_tls_empty_certs() {
+ * Cert/key/ca being NULL is valid — the function will attempt to create an
-  Server* s = server_create(0);
+ * SSL context without client certificates. */
-  EXPECT_NOT_NULL(s);
+static void test_tls_connect_null_paths() {
+  tls_global_init();
 
-  /* Empty string paths - SSL_CTX_use_certificate_file will fail, but function returns false */
+  Client* client = client_create();
-  bool ok = server_create_tls(s, "", "", NULL);
+  EXPECT_NOT_NULL(client);
+
+  /* Connect to invalid address — will fail at connect() step */
+  bool ok = client_connect_tls(client, "127.0.0.1", 1, NULL, NULL, NULL);
   EXPECT_FALSE(ok);
-  EXPECT_NULL(s->ssl_ctx);
 
-  server_delete(&s);
+  client_delete(client);
-  EXPECT_NULL(s);
+}
+
+/* Test server_create_tls with bad cert paths.
+ * The function should fail gracefully. */
+static void test_tls_server_bad_cert() {
+  tls_global_init();
+
+  Server* server = server_create(0);
+  EXPECT_NOT_NULL(server);
+
+  /* Load bad cert paths — should fail and return false */
+  bool ok = server_create_tls(server, "/nonexistent/cert.pem", "/nonexistent/key.pem", NULL);
+  EXPECT_FALSE(ok);
+
+  server_delete(&server);
 }
 
 void test_transport_tls() {
   test_tls_global_init();
-  test_server_create_tls_without_certs();
+  test_tls_global_init_twice();
-  test_client_connect_tls_fail();
+  test_tls_connect_bad_cert();
-  test_server_create_tls_empty_certs();
+  test_tls_connect_null_paths();
+  test_tls_server_bad_cert();
 }