- parse_ull_arg() rejects a leading '-'/'+' (strtoull would silently wrap
-1 to ULLONG_MAX) and --chunk-size/--delta-max enforce their upper bounds.
- Escape local untrusted paths before logging (client_send, scanner,
--filter rule, pattern-file reads) with output_escape(..., 8-bit mode).
- Read --exclude-from/--include-from through the bounded line reader.
- Open --log-file with O_NOFOLLOW|O_CLOEXEC, mode 0600, via open+fdopen;
create --write-batch with O_NOFOLLOW|O_CLOEXEC, mode 0600.
- Reject --dry-run together with --write-batch (dry-run must not write the
batch file), alongside the existing --read-batch/--only-write-batch rules.
Tests: signed/oversized numeric rejection, over-long pattern file, dry-run +
write-batch unit and integration coverage.
--dry-run --server-host=H (or TLS / source-bind --address) silently ran the
client-side manifest even though a real run contacts the server. Add a
client-only, never-serialized server_host_set bit (alongside the existing
server_port_set) and extend dry_run_targets_server so every explicit remote
target contacts the receiver.
Also make incremental_check return the dry-run code (4) only when the
session actually requested dry-run; a stray STATUS_DRY_RUN_TRANSFER from a
hostile/buggy peer is now a logged protocol error (STATUS_ERROR) instead of
falling through to send file data and desync. Both normal send_single_file
callers handle rc == 4 explicitly as an abort.
Address review/security findings in the 2.21.0 error-detail feature:
- Keepalive drain no longer erases the terminal detail: capture/clear is
skipped for STATUS_KEEPALIVE so the reason the peer just sent survives the
owed keepalive replies.
- Replace the capture path with a dedicated protocol_receive_error_detail:
the declared length is validated against MAX_ERROR_DETAIL_BYTES before any
allocation, over-cap bodies are drained through a fixed scratch buffer (so
the stream never desyncs), in-cap bodies read straight into the thread-local
detail buffer, and session->max_alloc is never raised. Lengths beyond
MAX_STRING_SIZE are treated as a fatal framing error.
- The detail body now honors the caller's deadline (timed/keepalive paths) and
polls the abort callback between drain chunks.
- Escape peer-controlled detail text with output_escape before logging it in
client_send.c and config.c.
- Clear io_error_detail in io_set_fds so a new connection on the same thread
cannot inherit a stale reason.
- Add unit tests for the keepalive-survival, over-cap drain, absurd-length
fatal framing, and deadline-clamped body read cases.
Today a server rejection sends a bare STATUS_ERROR and the reason only
reaches the server log, so the client cannot say why a transfer was
refused. Add an optional, bounded server->client error-detail frame:
- Status gains STATUS_ERROR_DETAIL appended LAST so existing wire
values are unchanged.
- send_error_detail(fd, msg) sends STATUS_ERROR_DETAIL followed by the
existing length-prefixed string primitive, slicing over-long messages
to MAX_ERROR_DETAIL_BYTES (4096).
- receive_status() (and the timed/keepalive status readers) always
consume the detail body and map the status back to STATUS_ERROR,
capturing the text into a thread-local buffer exposed by
protocol_last_error(); a bare STATUS_ERROR leaves it cleared. Every
existing call site keeps working and the stream cannot desync.
- Upgrade the daemon module gate / config validation (config.c), the
final transfer failure (server.c) and receiver-side path/node
validation (file_receive.c) to send a concrete reason; surface it on
the client in client_send.c/config.c.
- Bump PROTOCOL_VERSION to 2.21.0 (CMake VERSION, CHANGELOG, docs) and
update the pinned config wire golden hash / CLI-version tests.
- Add tests/test_protocol_error.c covering mapping+capture, the
over-long bound, bare-error clearing, and thread-locality.
--dry-run now handshakes with a remote/daemon receiver and reports what
WOULD transfer/skip based on receiver state, mutating nothing on either
side.
- Serialize Config.dry_run into the wire config frame and append
STATUS_DRY_RUN_TRANSFER to the status enum (no renumbering); bump
PROTOCOL_VERSION/CMake VERSION/CHANGELOG/golden wire to 2.21.0.
- Receiver: receive_incremental_check_ex runs the normal read-only
decision and answers STATUS_OK (skip) or STATUS_DRY_RUN_TRANSFER
(would transfer) with no basis materialization/append/delta/full
transfer. All mutation sites are guarded by !dry_run: file store,
manifest deletes, --mkpath root creation, --delay-updates staging,
publication, directory-time application, and outcome acks.
- Client: send_dry_run_remote connects, sends the config, checks each
regular file and prints the would-transfer set + trailer; no file data
or delete manifest is sent. Plain local destinations keep the
client-side manifest.
Data charged against a ProtocolSession kept only the charge amount, so
data_destroy released it from whatever session was thread-locally bound
at destroy time. Destroying a received Data on another thread, after the
session was unbound, or while a different session was bound leaked the
originating session's budget and underflowed the other's.
Add Data.owner, set it whenever protocol_receive_data_limited charges a
session, and have data_destroy release against that owner directly via
the newly-exported protocol_release_memory_for_session. Uncharged Data
(owner NULL) keeps the previous bound-session fallback.
Add a unit test proving a Data acquired on session A is released to A
even when unrelated session B is bound at destroy time.
Review fixes for Phase 7 Wave D.
#1 (HIGH): STATUS_DIR_TIMES entries no longer create directories. A new
receiver-only File.dir_time_only flag marks dir-time entries; file_save_to_disk_full
short-circuits them as FILE_SAVE_SKIPPED before any device/dir branch, so the sink
still accumulates metadata into the deferred DirTimeList but creates nothing. Empty
source dirs stay untransferred (-a), -m/--prune-empty-dirs semantics are preserved,
and a pre-existing regular file/symlink at an empty-dir mirror path no longer aborts
the transfer. dir_time_list_apply fstatat()s the leaf (AT_SYMLINK_NOFOLLOW) and skips
absent/non-directory paths QUIETLY; only a real existing directory is stamped.
Also initialize File.dir_time_only in file_create() (uninitialised garbage otherwise).
#2 (MED): send_dir_times() chunks entries into repeated STATUS_DIR_TIMES frames of at
most MAX_MANIFEST_ENTRIES, matching the receiver's per-frame bound; the tautological
> INT_MAX check is gone.
#3 (LOW): dir_time_list_add() assigns each grown array right after its realloc (no
dangling) and advances capacity only after both succeed.
#4 (LOW): RSYNC_COMPAT.md -- STATUS_MKDIR carries metadata, dir times are transmitted
via STATUS_DIR_TIMES and applied at the end, empty dirs are still never created; -m
rationale, -O row and Wave D notes updated. Summary counts untouched.
#5 (LOW): integration tests for the three #1 scenarios (empty-dir non-creation under
-a and -a -m, collision non-abort), scanner test now covers empty-dir capture, and
test_file_restore_symlink_metadata asserts the positive apply path when supported.
PROTOCOL_VERSION stays 2.17.0; config-frame layout unchanged.
Wave D of Phase 7. Make -O/--omit-dir-times and -J/--omit-link-times real by
preserving directory and symlink times, and mark --secluded-args as an explicit
Impossible/Divergence no-op.
Wire: PROTOCOL_VERSION 2.16.0 -> 2.17.0. Adds a terminal STATUS_DIR_TIMES frame
(int count + (wire path, metadata) pairs) sent after all file data and the
optional delete manifest. STATUS_MKDIR also carries metadata for --dirs entries.
Config-frame layout is unchanged.
Sender: the recursive scanner captures every traversed source directory (both
DirectoryScanner and the parallel scanner root + workers, appends mutex-guarded)
into a shared list; the single-threaded and -m paths transmit it last.
Receiver: a DirTimeList accumulates received directory metadata and applies it
with fd-relative no-follow utimensat only at the very end -- after all children,
after the commit-style --delete, and after --delay-updates publication -- in the
single-threaded success frame and in server.c after the -m threads join. -O skips
the application. Symlink metadata is applied at link creation with
utimensat/fchownat/fchmodat AT_SYMLINK_NOFOLLOW; -J suppresses only link times.
identity_apply_ownership_link shares the identity resolver with the fd path.
Docs: -O/-J rows -> Implemented; --secluded-args -> Impossible/Divergence;
--protocol accepted/rejected values and Phase-6/7 notes updated.
Tests: unit (scanner dir capture, DirTimeList apply, symlink metadata, protocol
version values) and integration (dir mtime round-trip + -O, symlink mtime
round-trip + -J, independent suppression), parameterized over single/multithread.
Implements the client-only residual-batch feature end-to-end:
- src/shared/batch.{c,h}: self-contained single-file batch codec using the
existing chunk_serialize/chunk_deserialize codec (byte-identical by
construction). Magic+format-version header (metadata mode is persisted into
the header so a batch is self-describing across machines), length-prefixed
chunk records, bounded reads that reject malformed/truncated/oversized
records cleanly.
- src/client/client_send.c: write_batch_from_source (deterministic separate
scan pass, loads every chunk's file images, emits header+records) and
apply_batch_to_dest (local apply to a destination root via
file_save_to_disk_full). No wire change, no server involved.
- src/client/client_validation.c: --write-batch XOR --only-write-batch;
--read-batch exclusive with both; --read-batch needs only a DEST,
--only-write-batch only a SOURCE.
- src/client/client_cli.c: main() drives the three batch modes without
connecting/transferring for read/only-write; --write-batch runs the live
transfer (single-threaded so the config survives) then emits the batch.
- tests/test_batch.{c,h} (unit: byte-identical roundtrip with and without
metadata; bad-magic/truncated/oversized rejection) + tests/integration/
test_batch.py (only-write no-server, read-batch no-source roundtrip,
--write-batch with a live transfer, conflict rejections).
- clang-format: realign PART-1 config.h comment block.
No PROTOCOL_VERSION bump, no config-frame field, no server flag.
Capture+transmit source atime (pre-read stat; O_NOATIME sender guard) and birth
time (statx STATX_BTIME); receiver restores atime with mtime (crtime not settable
portably -> transmitted, explicitly not applied). --open-noatime is client-only.
-O/-J documented as accepted no-ops (FastSync never preserves dir/symlink times).
Wire: metadata frame gains atime/crtime val+sec+nsec; PROTOCOL_VERSION
2.11.0->2.12.0. Review fixes: gate atime capture to Linux (no epoch clobber on
non-Linux), close fd on fdopen failure, honest -O/-J status (Compat no-op).
Source files sharing (st_dev,st_ino) are recreated as hard links on the
destination; only the first member's data crosses the wire (siblings ride a
payload-less STATUS_HARDLINK frame). Ordering requires the single-FIFO-writer
receiver + forced sequential scan (documented). link()-failure falls back to a
byte-identical local copy. Rejects -s/--append. PROTOCOL_VERSION 2.11.0->2.12.0.
Review fixes: delete the dead HardLinkRegistry (ordering holds by FIFO writer),
and --existing no longer aborts when the first member is absent but the sibling
exists (leaves the sibling in place).
BLOCKER: an absent mirror whose PARENT directory does not exist on the
destination (a deeper --files-from missing entry, -R or full-mirror layout) was
treated as a hard failure because file_open_secure_parent returned -1 when the
parent was missing. That aborted the whole run, skipped the --delete extras
walk, and tore down an early --delete-before/during connection, contradicting
'missing mirror = no-op / all-missing succeeds'. A parent-open failure is now a
no-op when errno is ENOENT/ENOTDIR (matching file_remove_tree_secure); only a
genuine I/O error fails the run.
Also: an already-absent mirror reached via unlinkat-ENOENT no longer prints
'Deleted: <path>' (a no-op dressed as a deletion); the per-path 'Deleted:' line
is printed only when an entry was actually removed.
Adds real algorithm selection (xxh64 default, plus md5 via OpenSSL EVP) and a
64-bit seed for the per-file whole-file digest used by the --incremental/
--checksum handshake and basis-dir content verification. The seed also feeds
the delta path's per-block xxHash32 strong checksum (low 32 bits) so an
explicit seed deterministically changes those digests too. Sender and receiver
hash identically: the algorithm id and seed cross the config wire frame and the
STATUS_CHECK handshake now carries a length-prefixed, bounded digest instead of
a fixed 64-bit value. Unsupported algorithm names are rejected at parse time
(never a silent no-op). PROTOCOL_VERSION bumped 2.9.0 -> 2.10.0; defaults
(xxh64, seed 0) preserve prior byte-for-byte behavior.
Implement rsync's append modes: when an existing destination file is SHORTER
than the source, the receiver negotiates a resume offset and only the tail is
transferred; the full file (retained prefix + tail) is rebuilt and installed
through the normal atomic store path, so the result is byte-identical to the
source whenever the prefix matches.
- --append: sends the tail without content-verifying the retained prefix
(rsync parity; the documented prefix-trust risk).
- --append-verify: verifies the retained prefix against the source's prefix
xxHash64 before appending and, on a mismatch, falls back to a clean full
transfer (never a corrupt prefix+tail blend).
New wire frames STATUS_APPEND / STATUS_APPEND_SIG / STATUS_APPEND_OK /
STATUS_APPEND_DATA; PROTOCOL_VERSION bumped 2.9.0 -> 2.10.0 (peers must match).
Both flags imply --incremental and are incompatible with -s (chunk
serialization) and --whole-file (rejected up front). Respects --inplace,
--partial/--partial-dir and --delay-updates via the shared store engine.
New flags parse onto the config; --delete-missing-args implies
--ignore-missing-args (order-independent) and does NOT imply --delete (rsync:
independent of other delete processing). The files-from preflight now classifies
listed-but-missing entries instead of hard-failing: under the flags each is
skipped (logged + counted, never silent) and the run succeeds for the rest,
including the all-missing case; an empty list stays a hard error. Under
--delete-missing-args the missing entries' destination mirrors (bare relative
path with -R, full source mirror otherwise) ride the manifest's third section in
both the single-threaded and -m senders; --dirs listed-but-missing entries are
skipped in the scanner.
scan_directory_multithreaded read directory_scanner_had_io_error() /
parallel_scanner_had_io_error() AFTER destroying the scanner object (a
heap-use-after-free on every successful -m run that recorded an io_error); the
flag is now captured before the destroy. As a second line of defense against
an empty-keep-set wipe, all four manifest send sites (sequential and -m, early
pre-scan and commit data pass) now refuse to transmit a keep-set manifest when
the scan that built it recorded an io_error and produced no keep entries: a
source that merely LOOKS empty because part of it was unreadable must never
delete the whole destination. A genuinely empty source (no io_error) still
sends its empty keep-set and prunes extras.
The scanners now record every entry pruned by user-selection rules
(--filter/-C/per-dir, --exclude/--include, --max-size/--min-size) as a
destination-relative protected path on a caller-supplied sink (thread-safe in
the parallel scanner); --files-from subset pruning and -R relative wire paths
are never recorded. The sender transmits these as manifest protected prefixes,
giving rsync's default --delete behavior (excluded mirrors survive) with
--delete-excluded opting back into deleting them. --ignore-errors makes an
unreadable source directory a recorded, non-fatal scan error: the run continues,
the deletion still runs, and the exit code reports the ignored error.
--prune-empty-dirs omits an empty source directory's explicit --dirs entry.
Empty directories were never transferred by recursive scans (rsync -m parity).
Basis dirs imply the per-file incremental check, which (like every whole-file
payload path in FastSync) is bounded by MAX_RECEIVE_WHOLE_FILE_SIZE. A source
tree with a larger file used to abort the whole run mid-stream on the receiver
with no client-side diagnostic. With basis dirs configured the client now
preflights the scan (respecting filters/size rules) and fails up front with a
clear error naming the offending file before connecting, matching the
documented 256 MiB whole-file limit instead of aborting silently.
The receiver performs the whole bounded deletion walk (up to
MAX_SERVER_DELETE_COUNT unlinks) before answering the delete-before/during
manifest, so its STATUS_OK reply can take far longer than the default 60 s
per-message receive window. Waiting with the default would make the sender
abort AFTER the deletion had already committed on the receiver. Add a timed
receive variant (receive_status_timed / protocol_receive_n_data_timed) and use
it for the early-manifest ACK with a 1 h explicit deadline; connection errors
and EOF still abort immediately.
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