Files
FastSync/src/shared/file.h
T
TapTap 0afda6b094 feat(checksum): --checksum-choice/--cc and --checksum-seed for whole-file digest
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.
2026-09-07 17:42:47 +02:00

85 lines
4.8 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 struct stat* stats);
void file_metadata_destroy(void* metadata);
bool file_write_to_disk(const char* path, const void* data, unsigned long long data_size,
bool inplace, bool sparse);
/* A configured fd without a canonical identity deliberately rejects paths. */
bool file_set_authorized_root(int fd, const char* canonical_path);
/* 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, const FileMetadata* metadata,
bool preserve_executability, 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,
const FileMetadata* metadata, bool preserve_executability,
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, const FileMetadata* metadata,
bool preserve_executability, const char* temp_dir);
bool file_to_disk_secure_no_replace(const char* path, const void* data,
unsigned long long data_size, bool sparse,
const FileMetadata* metadata, bool preserve_executability,
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. */
bool file_to_disk_secure_link(const char* path, const char* basis_path, const void* data,
unsigned long long data_size, const FileMetadata* metadata,
bool preserve_executability, bool use_fsync, const char* temp_dir);
#endif