Pure structural split of src/shared/file_receive.c into focused translation
units behind the unchanged file_receive.h facade:
- file_save.c : save-to-disk, special nodes, --delay-updates staging
- incremental_check.c : xattr/delta/basis/fuzzy receive + check state machine
- delete_commit.c : manifest receive + delete budget walkers
- file_receive.c : wire receive dispatch + deferred dir metadata
The shared receive_file_xattrs helper and MAX_FILE_DATA_SIZE are declared in
incremental_check.h. file_save_to_disk_full_ex is decomposed into static
helpers (validation, special dispatch, dir/symlink creation, path resolution,
pre-write policies, data install) routed through one cleanup epilogue.
No behavior change.
Three receiver security fixes from the audit:
1. --temp-dir symlink escape (High): file_open_temp_dir() opened the
client-controlled scratch dir with a bare open(), so a symlink planted
under the receive root let a peer redirect receiver scratch files
outside the authorized root. The opened dir is now judged by the REAL
path of its fd (via /proc/self/fd), and any target outside the
authorized receive root is refused with a logged error (EACCES). An
in-root symlink (the EXDEV cross-filesystem fallback case) still works,
and the no-root local batch path is unchanged.
2. setuid/setgid/sticky under SUPER_MODE_OFF (High): the special bits were
applied under --perms (and via --chmod) even when the connection forbade
super-user activities. FileAttrPolicy gains super_permitted, set by
file_attr_policy_from_config() from privilege_super_mode_permitted();
metadata_mode_for_policy(), the symlink path, the special-node creation
path, and the deferred directory-mode apply now strip the special bits
when it is false. Exact rsync semantics are preserved when permitted.
3. daemon umask (Low): daemonize() forced umask(0), so implied parent
directories created without -p were world-writable 0777. Set the
conventional daemon umask 022 instead (rsync never forces 0); -p/-a mode
preservation is unaffected because it restores modes via fchmod.
Tests: new unit tests for file_open_temp_dir confinement and the
masked/unmasked special-bit policy (incl. the --chmod path), a daemon
world-writable-dir regression test, an integration escape test, and a
root-only integration test asserting special bits are masked without
--allow-super. The old cross-filesystem test encoded the vulnerable
behavior (symlink target outside the root) and is replaced by the escape
test; the EXDEV fallback code is retained for in-root links.
Resolve a relative --compare-dest/--copy-dest/--link-dest DIR against the
destination directory and append the file's transfer-relative name, as
rsync 3.4.1 does, instead of appending FastSync's source-mirrored wire
path (the historical spelling stays as a fallback for existing layouts).
Stop inheriting the ordinary delta engine's 16 KiB minimum and 10x size
ratio in the -y/--fuzzy candidate search: rsync's find_fuzzy has no
delta-size gate, so an oversized or sub-16-KiB sibling is now reused.
The ordinary delta path's bounds are unchanged.
- receiver stats: exclude basis-dir materializations (--link-dest/--copy-dest)
from created/literal tallies; rsync reports 0 for a basis hit, so a fresh
--link-dest --stats run now matches (differential test_link_dest_stats_matches_rsync)
- filter wire block: reject a pattern above the glob evaluation bound and lower
MAX_FILTER_RULES to 1024, so a crafted rule list cannot amplify delete-walk
glob work or install a rule that silently never protects
- negative tests for over-cap count and over-long pattern
- README: correct --delete default, --stats/--progress description, add
--delete-commit; RSYNC_COMPAT stale version labels/overclaim fixed
- new bounded config-wire block (BLOCK_PROTECT_RULES) serializes the sender's
compiled filter rules to the receiver (bounded count + 256 KiB patterns;
strict action/sides validation)
- receiver evaluates protect/risk in the whole-tree extras walk and the
per-directory delete plans, so a dest-only entry matching 'P' is kept like
rsync; dry-run would-delete enumeration also honours it
- --filter flips to parity (115/11/31); per-dir merge receiver re-derivation
remains the documented residual
- PROTOCOL_VERSION 2.27.0 -> 2.28.0; STATUS_STATS gains literal_bytes and
the created reg/dir/link/special counters (golden wire updated)
- receiver reports which destination entries it newly created, including
implicitly-created parent directories below the logical transfer root, so
Number of created files carries rsync's per-type breakdown
- Literal data is now exact for a delta transfer (receiver counts the literal
fragments it stored)
- differential-tested vs rsync 3.4.1 for fresh-create, update and delta
- Wire: config frame gains report_deletes (protocol 2.26.0 -> 2.27.0); the
receiver lists actually-removed paths in the STATUS_STATS path list, so the
sender prints rsync's `deleting PATH` / `*deleting PATH` lines for a real
--delete run (and -i/out-format). Observers threaded through the manifest,
missing-args and per-directory delete engines; golden wire len/hash updated.
- bwlimit: throttle now paces like rsync 3.4.1 -- ~100ms burst capacity and the
sleep is no longer credited as refill, so 4 MiB at 1024/2048 KiB/s matches
rsync within ~4% (was ~2x too fast).
The single-threaded and -m receivers never populated ReceiverStats.matched_data
or .deleted_files, so --stats always printed 0 for both even when rsync
reported nonzero. Track the bytes reconstructed from the basis file while
applying a delta, and tally the delete-commit counts (manifest and
per-directory sessions) into the receiver stats. The -m pipeline now carries
its own stats/would-delete fields and emits the STATUS_STATS frame before the
terminal success, so --threads finally reports the counters and renders
-n --delete lines.
Also normalize the -n --delete would-delete enumeration's absolute basis
prefixes exactly like the real commit path (fixing an over-report) and fix the
basis_delete_relative off-by-one when the receive root is '/'. Unit tests
cover the root mapping and the basis protection; integration tests cover
matched/deleted stats for both receivers and the --threads dry-run delete
lines.
Add the STATUS_STATS end-of-transfer receiver report (matched/deleted
counters plus a would-delete path list) behind the report_stats wire
bool, and a read-only delete_extras_list walker. --stats now renders
true wire byte totals and the receiver-reported deleted count; a
server-contacting -n --delete prints transfer-relative '*deleting' lines
matching rsync's itemize layout.
Stream one delete plan per source directory from sender to receiver instead of
a single whole-tree keep-set manifest:
- --delete-during applies each directory's extras as its plan arrives, before
that directory's data (rsync's generator-order deletion).
- --delete-delay snapshots each directory's extras while the plan arrives and
commits the removals only after a fully-successful transfer, so files created
after the scan survive (matching rsync's delete-delay, not delete-after).
- Type conflicts (a destination file blocking a source directory, or vice
versa) are cleared immediately in both modes, so the nested write succeeds.
The plan carries the destination-relative directory, its kept child directory
names and its kept child file names; the first frame also carries the global
protected prefixes, size-skipped prefixes and --delete-missing-args paths.
--delete-before keeps the existing whole-tree early manifest; plain --delete and
--delete-after keep the end-of-transfer manifest commit.
Preserves the existing safety surface: protected/size-skipped prefixes and the
--delay-updates/basis skips are honored at any depth, deletion is scoped to the
synchronized directories (--files-from), MAX_SERVER_DELETE_COUNT and
--max-delete (partial + exit 25) are shared across plans, symlinks are never
followed, and paths are confined to the receive root.
- --chmod no longer implies --preserve-perms; repeated --chmod options
accumulate, and D/F/X selectors plus s/t special bits are supported with
rsync's exact parse_chmod/tweak_mode semantics.
- Stop masking group/other write and setuid/setgid/sticky: -p copies the
source mode exactly, no-p new entries use source&~umask, directories keep
setgid/sticky, and special nodes follow the same rules.
- Apply ownership before mode on the fd path so a chown cannot clear the
setuid/setgid bits -p just restored (rsync order).
- Update unit and integration tests, including differential checks against
rsync 3.4.1.
Address review findings on feat/rsync-parity:
- confine --temp-dir below the receive root (reject absolute/.. like
backup-dir/partial-dir); keep EXDEV non-atomic fallback
- floor server session I/O deadlines at SERVER_IO_TIMEOUT_SEC (60s) and
install it on the socket layer at startup (slow-loris)
- charge each --delete-missing-args directory removal once and clamp the
extras-walk remaining budget so it can never underflow past --max-delete
- normalize --compress-choice=auto to zstd client-side and accept it on
receive so auto transfers no longer fail
- map received --max-alloc=0 to MAX_SERVER_ALLOC (receive path only)
- zero File.dest_state; include log-file-format in report_dest_info;
add STATUS_DELETE_LIMIT name; recognize --skip-compress as a
separate-value option; OOM-guard send_list_only root entry; drop the
dead -M= branch; record the bare relative protected prefix for -R
size-prunes in both scanners; refresh delete-manifest comment
- pin the rsync tarball sha256 and bump integrator image to v11
Tests: temp-dir rejection/relative/cross-device, server timeout floor,
delete-missing dir budget regression, compress-choice=auto e2e,
max-alloc=0 receive mapping, dest_state, report_dest_info modes,
skip-compress dash value, -M short forms, -R root size-prune mirror
protection (rsync 3.4.1 confirmed).
A non-empty --delete-missing-args directory removed under --force/--delete
now has its contents deleted entry-by-entry through the budgeted walker, so
every deleted file/dir counts toward --max-delete exactly like rsync (a
capped run leaves the remaining entries and exits 25).
- Scope the --delete extras walk to directories synchronized by the
transfer: add a synchronized-directory section to the delete manifest
(protocol 2.23.0) so --files-from subsets no longer delete untransmitted
paths outside listed directory subtrees (data-loss fix).
- Separate --max-size/--min-size prune protection from --delete-excluded so
size-pruned source mirrors survive (rsync parity).
- Unlink extraneous destination symlinks instead of skipping them.
- Make --max-delete partial (delete up to N, skip the rest) and exit 25;
accept negative values as unlimited.
- Draw --delete-missing-args deletions from the shared --max-delete budget.
- Honor --force during --delay-updates publication.
Add unit and integration regression tests; update the pinned config wire
golden and version strings for the 2.23.0 manifest/status additions.
#289 checksum/compression:
- -c/--checksum now implies the incremental content quick-check (without
implying -t), so an unchanged file is skipped like rsync.
- --checksum-choice/--cc accepts xxh64/xxhash, xxh3, xxh128, md5 and auto;
md4/sha1/none and the two-name form are rejected by name.
- --compress-choice/--zc rejects lz4/zlib/zlibx by name (zstd/none/auto kept).
- --checksum-seed=0 is randomized per transfer and sent on the wire.
- --skip-compress uses rsync 3.4.1's default suffix list; slash separators and
dot-less suffixes are accepted.
- add --no-whole-file.
#295 timeouts/alloc/temp-dir:
- --timeout default 0 (disabled), --contimeout default 60; 0 disables both,
plus --no-timeout/--no-contimeout.
- --max-alloc=0 means no allocation limit (was rejected).
- --temp-dir accepts any dir, requires it to exist, and falls back to a
non-atomic copy on EXDEV instead of aborting.
#296 connectivity/daemon:
- -M/--remote-option is rejected for daemon/TCP destinations (SSH-only).
- --trust-sender clarified as receiver-local; server-path tests added.
- --stop-at accepts rsync's full date form (y-m-dTh:m etc.).
Adds unit and integration coverage; no wire-field change, PROTOCOL_VERSION stays
2.22.0.
- #286: --numeric-ids is a mapping modifier only; it no longer activates
chown by itself (identity_active_enabled/owner/group predicates), and
--fake-super stores the resolved mapping instead of real-chowning.
- #286: apply owner/group to directories via the deferred directory
metadata path; capture+transmit+apply directory xattrs/ACLs (-aX/-aA),
including default ACLs, in STATUS_MKDIR/STATUS_DIR_TIMES.
- #294: --usermap/--groupmap support inclusive ranges, '*', empty FROM
(unnamed ids), and receiver-side TO name resolution; --chown mixing with
a same-side map is rejected like rsync.
- Protocol 2.22.0 -> 2.23.0 (map wire entry gains from_hi + to_name;
dir frames gain a bounded xattr block).
#287:
- --safe-links: keep safe in-tree links AS symlinks and skip unsafe
(absolute or ".."-escaping) ones, mirroring rsync's unsafe_symlink().
Skipped links are recorded as delete-protected so --delete does not
remove their destination mirror (no silent data loss).
- --copy-unsafe-links: preserve safe links as symlinks and dereference
only unsafe ones.
- --munge-links: receiver-side rewrite storing /rsyncd-munged/-prefixed
targets (rsync parity), replacing the no-op #SYMLINK sender prefix.
- -l: store the target verbatim, including absolute and ".." targets
(rsync -l parity); the old receiver containment silently dropped them.
#288:
- --specials: recreate unix-domain sockets via mknod(S_IFSOCK), which
Linux permits unprivileged; keep EEXIST/EPERM skip behavior.
- --copy-devices: copy a device's content into a regular file when
requested; skip unrequested non-regular entries like rsync's default.
#291:
- Compile --exclude/--include/--exclude-from/--include-from into the SAME
ordered rule list as --filter/-f (first match wins), so the common
`--include='*.txt' --exclude='*'` idiom and include-alone semantics match
rsync. The legacy per-kind scanner arrays are no longer applied.
- -x/--one-file-system emits the cross-device mount-point directory entry
(empty) instead of dropping it, in both the sequential and parallel scanners.
- Stop passing the legacy arrays to the scanner; document -f is --filter.
#292:
- New src/shared/format.c/.h: rsync "big_num" (comma-grouped integers) and
decimal -h human sizes, %M/%t timestamp, and the STATUS_DEST_INFO codec.
- Receiver answers each STATUS_CHECK with a pre-transfer destination snapshot
(new report_dest_info wire field + STATUS_DEST_INFO, PROTOCOL_VERSION
2.23.0) so the sender can render true itemize columns.
- Itemize now emits rsync-correct update/type chars and c/s/t/p/o/g columns
for files, dirs, symlinks and hard links, comparing size/time/perms/owner/
group against the reported destination.
- --out-format gains %i %n %f %l %b %M %t %o %p %B %U %G %L; %f is the
relative display path, %M the YYYY/MM/DD-HH:MM:SS form, %b the literal
bytes sent.
- --list-only prints transfer-relative names, directory entries and ls-style
grouped sizes.
- --stats prints rsync's multi-line block on stdout; -h uses decimal units.
Tests: unit tests for the filter ordering, format primitives, itemize
columns; integration + differential tests against real rsync 3.4.1 for
itemize/out-format/list-only/selection and -x. Golden wire len/hash and
protocol version strings updated for 2.23.0.
Split FastSync's single use_metadata bundle into four independent rsync-parity attributes: preserve_perms, preserve_times, preserve_owner, preserve_group. use_metadata is now a derived transport bit (config_derived_use_metadata).
CLI: real -p/--perms, -t/--times, -o/--owner, -g/--group plus --no-perms/--no-times/--no-owner/--no-group (short and long) and --no-preserve; -a is now rsync -rlptgoD; --preserve = -pt; -A implies -p; -X does not; --chmod implies -p; --usermap/--groupmap/--chown imply owner/group per side; --incremental/--delta still auto-preserve unless negated.
Receiver: per-attribute FileAttrPolicy gating for files, dirs (modes applied at end of transfer), symlinks and specials; rsync -E read-bit rule; new files get source_mode & ~umask sanitized (no group/other write); per-side identity resolution; deferred directory metadata; batch dir-metadata replay; daemon modules without 'client owner = yes' no longer refuse plain -a but force super off (no ownership) with a warning.
Wire: PROTOCOL_VERSION 2.21.0 -> 2.22.0 (four appended config bools, golden 653 / 95530566005420798). FileMetadata/chunk/batch framing unchanged. Docs/CHANGELOG/CMake updated to 2.22.0.
Follow-up to a237043 addressing three security/correctness re-review findings.
(1) MEDIUM: a server-contacting --dry-run with --compare-dest/--copy-dest/
--link-dest still read and hashed the basis file and compared it with the
client-supplied digest, a 1-bit content oracle. basis_match_find() gains a
hash_content parameter; the dry-run shortcut passes false and returns no
match without touching basis bytes, so an otherwise-matching entry is
reported as would-transfer. The real (non-dry-run) path is unchanged.
(2) LOW: xattr_capture_path() hardcoded preserve_acls=true, so the receiver's
hard-link copy fallback re-applied system.posix_acl_* even when -A was not
negotiated. The function now takes preserve_acls and members.* is
unaffected; scanner and receiver callers thread the negotiated flag.
(3) INFO: the --fsync --link-dest temp reopen now uses O_NONBLOCK and treats
a raced-in FIFO's ENXIO as a benign fsync-skip instead of blocking.
Tests: dry-run + basis unit test (asserts would-transfer, no content read) and
integration test; xattr capture ACL-filter test. Verified strict build, ASan,
clang-format, cppcheck, and the CI integration subset.
Address confirmed receiver security findings B1-B6:
B1 (HIGH): add O_NONBLOCK to the three receiver read-opens that opened an
existing destination/basis entry before the S_ISREG gate
(incremental_check_open_destination, basis_open_regular, hardlink_read_source)
so a client-planted FIFO can no longer block the receive thread forever while
the post-open type gate still rejects it.
B2 (HIGH/MED): --inplace now fstatat(AT_SYMLINK_NOFOLLOW)-probes the target and
refuses any existing non-regular entry, opens with O_NONBLOCK, and re-checks
S_ISREG on the opened fd. This stops a FIFO from hanging the open and stops a
char/block device from being written directly (bypassing --write-devices).
B3 (MED): under --dry-run the incremental quick-skip no longer reads/hashes the
destination file for --checksum/--delta; it decides from metadata only and
reports would-transfer when the comparison is inconclusive, closing the
read-only-module content-hash oracle.
B4 (LOW): xattr_name_appliable() now gates the two system.posix_acl_* names on
preserve_acls (--acls), not the derived use_xattrs (--xattrs OR --acls). The
receiver drops (never applies) ACL entries when -A was not negotiated while
keeping user.* working for -X.
B5 (INFO): receive_manifest_section() charges a per-entry overhead against
MAX_MANIFEST_BYTES and the aggregate entry count across all three sections is
capped at MAX_MANIFEST_ENTRIES.
B6 (MED): data_charge_session() reserves decompressed/chunk-copy bytes against
the owning ProtocolSession (MAX_CONNECTION_MEMORY) and records them on the Data
so data_destroy() releases them via the Data.owner path. Applied to the
whole-file/append/delta decompression sites and chunk_deserialize() per-file
copies; a missing session owner degrades to the previous uncharged behavior.
Tests: FIFO destination/basis non-hang (with alarm), --inplace FIFO/device
refusal, dry-run no-read oracle test plus updated metadata-only dry-run tests,
ACL-without--acls drop, manifest total-entry cap, and chunk session charging.
--dry-run --read-batch=FILE still wrote to the destination because
batch_read_apply -> file_save_to_disk_full bypassed the per-caller
!dry_run guards. Guard file_save_to_disk_full and manifest_delete_all
directly (return SKIPPED/no-op) so every save/delete path is mutation-free
in dry-run, and keep the per-caller guards. Reject --dry-run combined with
--read-batch/--only-write-batch at CLI validation with a clear error (a
dry-run of a local batch apply is not meaningful).
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.
The per-file STATUS_CHECK fast path was a single 534-line function that
was hard to review. Extract it into small static helpers called in order
by a short linear orchestrator:
- incremental_check_receive_request (receive/validate request frame)
- incremental_check_open_destination (secure open + stat)
- incremental_check_quick_skip (metadata/content skip decision)
- incremental_check_try_basis (compare/copy/link-dest)
- incremental_check_try_append_resume(--append tail resume)
- incremental_check_try_delta (block delta)
- incremental_check_try_fuzzy (--fuzzy basis)
- incremental_check_receive_full (STATUS_NEXT + whole file)
Pure refactor: the ordered sequence of wire operations
(send_status/send_n_data/receive_n_data/receive_status/receive_wire_str)
is byte-for-byte identical to the original, and every resource cleanup
is preserved (a unified idempotent cleanup replaces the duplicated
per-path close/free blocks). No functional changes.
--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.
Deduplicate the repeated directory-time capture gate
(`config->use_metadata && !config->omit_dir_times`) used by the
sender-side (multiprocessing.c) and receiver-side (receiver.c) sinks
into a single predicate declared next to the DirTimeList machinery in
file_receive.h and defined in file_receive.c.
Behavior preserved: identical short-circuit condition and semantics,
no signature or protocol changes.
- A6: escape attacker-controlled file paths and the receive root in log
lines (file_receive, server, protocol DEBUG) with output_escape()
- A8: identity_set_active() returns bool and fails closed when a requested
usermap/groupmap cannot be deep-copied; handler refuses the connection
- remove the const cast and duplicate super_mode clamp from
server_module_gate via an explicit override the handler applies once
- release the identity snapshot on the queue_create failure path
- refactor identity_parse_copy_as to a single cleanup tail and drop the
duplicated group error format specifier
- file_ensure_directory_secure() now chowns a final directory it creates under
--copy-as and fails on error; the symlink parent-creation call site propagates
it. The is_dir branch fails when the confined parent cannot be opened under
--copy-as. Closes the residual wrong-owner gap for synthesized/symlink
parent directories.
- file_restore_symlink_metadata() early NULL return is copy-as-aware.
- Preserve errno across the implicit-parent failure cleanup.
- Neutral skip messages (the clamp, not --no-super, may be responsible).
- Daemon copy-as test tolerates the non-root privilege refusal; usage text lists
--copy-as.
- H3: a daemon module without 'client owner = yes' now also has super-user
device activity forced off (char/block mknod, --write-devices), so a root
daemon can no longer be made to create/write raw devices under AUTO. The
entries are skipped, preserving ordinary -a pushes.
- H1/H2: propagate a failed required --copy-as chown from symlink metadata
restore and implicitly-created parent directories, so the entry (and run)
reports failure instead of a wrong-owner success.
- Docs/help/headers updated for A2/A3 and the device clamp; startup warning
spells out the client-owner risk.
- Tests: daemon device clamp (skipped without opt-in, created with opt-in),
updated --super/--fake-super expectations.
A1: daemon refuses every client-chosen ownership/super-user request
(--numeric-ids/--chown/--usermap/--groupmap/--fake-super/--copy-as/--super)
unless the selected module opts in with 'client owner = yes'.
A2: fake-super owner replay requires an explicit ownership identity policy.
A3: --super no longer implies --numeric-ids (ownership stays opt-in).
A5: a failed --copy-as chown marks the entry failed instead of reporting
success with the wrong owner.
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