Files
FastSync/src/shared/file.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

150 lines
9.0 KiB
C

#ifndef FILE_H
#define FILE_H
#include "file_send.h"
#include "file_receive.h"
#include "file_types.h"
#include "checksum.h"
#include <stdbool.h>
#include <stdint.h>
#include <sys/stat.h>
/* File/FileMetadata lifecycle, local disk helpers, and secure filesystem
primitives shared by the send/receive pipelines. */
File* file_create(const char* path);
void file_destroy(void* item);
bool file_load_data(File* file);
/* Compute the whole-file content digest of `file` with the negotiated
* --checksum-choice algorithm and --checksum-seed. Writes the digest into
* `out` (capacity `out_capacity`) and its length into `*out_len`. Returns
* false on read/allocation failure or when the digest would not fit. */
bool file_checksum(File* file, ChecksumAlgo algo, uint64_t seed, uint8_t* out, size_t out_capacity,
size_t* out_len);
size_t file_content_to_buffer(File* file);
FileMetadata* file_metadata_create(const char* path, const struct stat* stats, bool capture_atime,
bool capture_crtime);
void file_metadata_destroy(void* metadata);
/* --open-noatime process-wide sender policy; see file.c. */
void file_set_open_noatime(bool enable);
bool file_get_open_noatime(void);
/* Capture the process umask ONCE, before any threads are created. Call this at
* the very top of main() in both entry points so the cached value is read while
* the process is still single-threaded: reading the umask needs a get+set round
* trip (umask(0); umask(old)), which would race against receiver threads
* creating files if it happened during the first write. Idempotent and safe to
* call more than once. */
void file_umask_capture(void);
/* Process-wide umask, captured once (thread-safe). Used to derive the mode of
* a brand-new destination like rsync: source_mode & 0777 & ~umask. Falls back
* to file_umask_capture() (behind pthread_once) if capture was never called. */
unsigned file_process_umask(void);
/* Open `path` read-only for transfer, honouring --open-noatime when set. */
int file_open_for_read(const char* path);
bool file_write_to_disk(const char* path, const void* data, unsigned long long data_size,
bool inplace, bool sparse);
/* Symlink trust-boundary helpers (Phase 4, symlink wave). --munge-links
* sender-side marker: every transmitted symlink target is prefixed with this
* while the flag is on; the receiver strips it to restore the real target. */
#define SYMLINK_MUNGE_PREFIX "#SYMLINK/"
char* file_symlink_munge(const char* target);
/* True when a lexical target is relative and contains no ".." component, so it
* can never escape the receive root once created beneath it. */
bool file_symlink_target_contained(const char* target);
/* Strip a leading SYMLINK_MUNGE_PREFIX from `target` (mutable, in place);
* returns true when a marker was removed. */
bool file_symlink_unmunge(char* target);
/* Create a symlink at `path` -> `target`, confined below the authorized root
* (O_NOFOLLOW parent walk, symlinkat; the target is never followed). Returns
* false when a directory already occupies `path`. */
bool file_symlink_at_secure(const char* path, const char* target);
/* --keep-dirlinks (-K) receiver process-wide policy: allow an in-root existing
* symlink-to-directory to be followed as a directory. */
void file_set_keep_dirlinks(bool enable);
/* --trust-sender receiver process-wide policy (Phase 5). When set, the
* receiver trusts that the sender already produced a clean file list and skips
* its own redundant up-front re-validation of incoming paths (the empty/".."
* rejection and the escaping-symlink-target containment). The low-level
* fd-relative confinement primitives below are deliberately NOT disabled by
* this flag, so a hostile sender still cannot escape the authorized root. */
void file_set_trust_sender(bool enable);
bool file_get_trust_sender(void);
/* Secure path/filesystem primitives (symlink-safe, O_NOFOLLOW, root-confined). */
bool file_path_exists_secure(const char* path);
bool file_stat_secure(const char* path, struct stat* st);
bool file_destination_is_newer_secure(const char* path, const FileMetadata* metadata);
int file_open_secure_parent(const char* path, char** leaf_out, bool create_dirs);
bool file_ensure_directory_secure(const char* path);
bool file_directory_exists_secure(const char* path);
bool file_rename_secure(const char* old_path, const char* new_path);
/* Remove the whole directory tree at `path` (confined, symlink-safe). Used by
--force to clear a non-empty destination directory that blocks an incoming
regular file. See the .c for the exact success semantics. */
bool file_remove_tree_secure(const char* path);
/* Open a private 0700 directory (creating it on demand) that must live below
the authorized root. Used for the --temp-dir scratch directory and the
--delay-updates staging directory. */
int file_open_private_dir(const char* dir_path);
/* The file_to_disk_secure* variants write a temporary copy in the destination
directory and atomically rename it over `path`. temp_dir is an absolute,
root-confined scratch directory (already validated by the caller): when it
is non-NULL the temporary copy is instead created there (with a name unique
across the whole scratch directory) and atomically renamed into the
destination directory once fully written and fsynced. A rename across
filesystems (EXDEV) fails the write with an error; the file is never
silently copied into place. Pass NULL for the historical same-directory
behavior. --inplace writes never use temp_dir. */
bool file_to_disk_secure(const char* path, const void* data, unsigned long long data_size,
bool inplace, bool sparse, bool preallocate, const FileMetadata* metadata,
FileAttrPolicy policy, const char* temp_dir);
bool file_to_disk_secure_with_fsync(const char* path, const void* data,
unsigned long long data_size, bool inplace, bool sparse,
bool preallocate, const FileMetadata* metadata,
FileAttrPolicy policy, bool use_fsync, const char* temp_dir);
/* With update enabled, an existing newer destination is left untouched. The
check is descriptor-based for inplace writes; atomic replacement still has
an unavoidable final rename race without filesystem locking. */
bool file_to_disk_secure_update(const char* path, const void* data, unsigned long long data_size,
bool inplace, bool sparse, bool preallocate,
const FileMetadata* metadata, FileAttrPolicy policy,
const char* temp_dir);
bool file_to_disk_secure_no_replace(const char* path, const void* data,
unsigned long long data_size, bool sparse, bool preallocate,
const FileMetadata* metadata, FileAttrPolicy policy,
const char* temp_dir);
/* Receiver write-path variant that also applies per-file xattrs (-X/-A) and the
* --fake-super stat xattr fd-relative before the final rename. `update` /
* `no_replace` / `use_fsync` mirror the plain wrappers above; `keep_partial`
* enables --partial best-effort retention of a failed write's temp. */
bool file_to_disk_secure_attrs(const char* path, const void* data, unsigned long long data_size,
bool inplace, bool sparse, bool preallocate,
const FileMetadata* metadata, FileAttrPolicy policy, bool update,
bool no_replace, bool use_fsync, const FileXattrList* xattrs,
bool fake_super, bool keep_partial, const char* temp_dir);
/* Atomic --link-dest install: replace `path` with a hard link to `basis_path`
(via a temp name + rename); fall back to a byte-identical local copy from
`data` when the link is impossible (EXDEV/EPERM/unsupported filesystem).
`metadata` is applied only on the copy fallback. `preallocate` applies to
that copy fallback only (a hard-linked file shares the basis inode and is
never re-allocated). */
bool file_to_disk_secure_link(const char* path, const char* basis_path, const void* data,
unsigned long long data_size, bool preallocate,
const FileMetadata* metadata, FileAttrPolicy policy, bool use_fsync,
const char* temp_dir);
/* Like file_to_disk_secure_link, but the byte-copy fallback also applies the
* per-file xattrs (-X/-A) and --fake-super stat xattr (fd-relative). On a
* successful hard link no attributes are applied (the shared inode already
* carries the basis's). */
bool file_to_disk_secure_link_attrs(const char* path, const char* basis_path, const void* data,
unsigned long long data_size, bool preallocate,
const FileMetadata* metadata, FileAttrPolicy policy,
bool use_fsync, const FileXattrList* xattrs, bool fake_super,
const char* temp_dir);
#endif