Files
FastSync/src/shared/metadata.h
T
TapTap 34970b961c feat: per-attribute preservation flags -p/-t/-o/-g with --no-* negations (protocol 2.22.0)
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.
2026-09-15 19:32:02 +02:00

84 lines
4.3 KiB
C

#ifndef METADATA_H
#define METADATA_H
#include "file.h"
#include "file_attr.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <sys/stat.h>
#include <time.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)
* int32_t atime_valid (-U/--atimes; protocol 2.12.0)
* int64_t atime_sec
* int64_t atime_nsec
* int32_t crtime_valid (-N/--crtimes; protocol 2.12.0)
* int64_t crtime_sec
* int64_t crtime_nsec
*
* 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 (68 bytes on most platforms).
*
* metadata_send()/metadata_receive() (protocol 2.20.0) frame the metadata as a
* single packed record: one int32 present flag (0 = absent) followed, when
* present, by exactly FILE_METADATA_WIRE_SIZE bytes of field data. This is the
* same present+fields byte layout metadata_to_buf()/metadata_from_buf() use, so
* the wire metadata is now one frame instead of one frame per field. */
#define FILE_METADATA_WIRE_SIZE (sizeof(int32_t) * 5 + sizeof(int64_t) * 6)
void metadata_to_buf(char** buf, const FileMetadata* m);
/* Decode one packed metadata record (an int32 present flag followed, when
* present, by FILE_METADATA_WIRE_SIZE field bytes) from `buf`, which has `len`
* readable bytes. Every read is bounds-checked against `len`, so the function
* can never over-read the caller's buffer: a too-short record, an absent
* (present == 0) record and a malformed record all return NULL. A successful
* decode returns a heap-allocated FileMetadata owned by the caller. */
FileMetadata* metadata_from_buf(const uint8_t* buf, size_t len);
bool metadata_send(int file_descriptor, const FileMetadata* m);
FileMetadata* metadata_receive(int file_descriptor, int* ok);
void file_restore_metadata(const char* path, const FileMetadata* metadata, FileAttrPolicy policy);
bool file_restore_metadata_fd(int fd, const FileMetadata* metadata, FileAttrPolicy policy);
/* Shared mode-policy helper: the single source of truth for the receiver's
* mode rule. Given a source mode and the destination's CURRENT mode, returns
* true and stores the exact mode to apply in *out_mode when `policy` requests
* a change, or false when it requests neither --perms nor --executability (the
* caller then leaves the destination mode alone). --perms wins over -E; the
* -E rule derives exec bits from the destination's read bits (rsync 3.4);
* group/other write is never granted from a client-supplied mode. Shared by
* file_restore_metadata_fd() and the --fake-super replay so the two cannot
* diverge. */
bool metadata_mode_for_policy(mode_t source_mode, mode_t current_mode, FileAttrPolicy policy,
mode_t* out_mode);
/* P7 Wave D: apply a SYMLINK's own metadata using no-follow primitives only
* (utimensat/lchown/fchmodat with AT_SYMLINK_NOFOLLOW), confined fd-relative
* under the authorized root. The link's mode is applied only when policy.perms;
* policy.times (further suppressed by `omit_link_times` for -J) applies the
* mtime with policy.atimes controlling the atime slot; ownership stays gated by
* the identity policy and by default is not applied.
* A null metadata or an unfollowable parent is a harmless no-op. Returns false
* only when a REQUIRED --copy-as ownership application failed, so the caller can
* report the entry as failed instead of claiming a wrong-owner success. */
bool file_restore_symlink_metadata(const char* path, const FileMetadata* metadata,
FileAttrPolicy policy, bool omit_link_times);
/* Compare timestamps using rsync's whole-second modification window. */
bool metadata_mtime_matches(time_t left_sec, long left_nsec, time_t right_sec, long right_nsec,
int modify_window);
#endif