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refactor: split file.c into file_send.c and file_receive.c

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- file.c: File/FileMetadata lifecycle and local disk helpers (~110 lines)
- file_send.c: client-side send path (file_send_single_calls, file_send_sendfile)
- file_receive.c: server-side receive/save path (file_receive, receive_incremental_check,
  receive_manifest, file_save_to_disk)
- file_types.h holds shared struct definitions; file.h remains an umbrella header
  so existing includes are unaffected
Completes the transfer/protocol separation started in PR #212
This commit is contained in:
TapTap
2026-08-30 13:59:43 +02:00
parent 3fa3e150ce
commit d639dfdc07
7 changed files with 789 additions and 732 deletions
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src/shared/file_receive.c
+588
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@@ -0,0 +1,588 @@
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "array_list.h"
#include "compression.h"
#include "config.h"
#include "data.h"
#include "delta.h"
#include "file.h"
#include "file_store.h"
#include "log.h"
#include "metadata.h"
#include "protocol.h"
#include "utils.h"
static bool path_is_within_root(const char* root, const char* path) {
size_t n = strlen(root);
return strncmp(root, path, n) == 0 && (path[n] == '\0' || path[n] == '/');
}
bool file_save_to_disk(const char* root_directory, const File* file, const Config* config) {
bool backup_enabled = config && config->backup;
bool inplace = config && config->inplace;
bool sparse = config && config->preserve_sparse;
const char* backup_suffix = (config && config->suffix) ? config->suffix : "~";
const char* backup_dir = (config && config->backup_dir) ? config->backup_dir : NULL;
const char* partial_dir = (config && config->partial_dir) ? config->partial_dir : NULL;
char *confined_backup = NULL, *confined_partial = NULL;
if (!file || !file->path || !file->data || has_path_traversal(file->path) ||
(backup_enabled &&
(!backup_suffix || backup_suffix[0] == '\0' || strchr(backup_suffix, '/') != NULL ||
strcmp(backup_suffix, ".") == 0 || strcmp(backup_suffix, "..") == 0))) {
log_message(LOG_LEVEL_ERROR, "Invalid file or path received");
return false;
}
/* These options arrive from the client. They are names below the server
root, never independent filesystem roots. */
if ((backup_dir && (backup_dir[0] == '/' || has_path_traversal(backup_dir))) ||
(partial_dir && (partial_dir[0] == '/' || has_path_traversal(partial_dir))))
return false;
if (backup_dir && !(confined_backup = path_cat(root_directory, backup_dir)))
return false;
if (partial_dir && !(confined_partial = path_cat(root_directory, partial_dir))) {
free(confined_backup);
return false;
}
char* resolved_root = NULL;
const char* actual_root =
(partial_dir && config && config->partial) ? confined_partial : root_directory;
resolved_root = realpath(actual_root, NULL);
if (resolved_root == NULL) {
if (mkdir_r(actual_root)) {
resolved_root = realpath(actual_root, NULL);
}
}
if (resolved_root == NULL) {
log_message(LOG_LEVEL_ERROR, "Failed to resolve destination root: %s", actual_root);
free(confined_backup);
free(confined_partial);
return false;
}
char* resolved_base = realpath(root_directory, NULL);
if (resolved_base == NULL || !path_is_within_root(resolved_base, resolved_root)) {
free(resolved_base);
free(confined_backup);
free(confined_partial);
free(resolved_root);
return false;
}
free(resolved_base);
char* disk_path = path_cat(resolved_root, file->path);
if (disk_path == NULL) {
free(confined_backup);
free(confined_partial);
free(resolved_root);
return false;
}
/* --update is receiver-side policy: never replace a newer destination. */
if (config && config->update) {
struct stat destination_stat;
if (stat(disk_path, &destination_stat) == 0 && file->metadata &&
destination_stat.st_mtime > file->metadata->mtime_sec) {
free(resolved_root);
free(confined_backup);
free(confined_partial);
free(disk_path);
return true;
}
}
if (backup_enabled) {
struct stat backup_stat;
if (stat(disk_path, &backup_stat) == 0) {
char* backup_path = NULL;
if (backup_dir) {
char* resolved_backup_dir = realpath(confined_backup, NULL);
if (!resolved_backup_dir) {
mkdir_r(confined_backup);
resolved_backup_dir = realpath(confined_backup, NULL);
}
if (resolved_backup_dir) {
char* backup_base = realpath(root_directory, NULL);
if (backup_base && path_is_within_root(backup_base, resolved_backup_dir))
backup_path = path_cat(resolved_backup_dir, file->path);
free(backup_base);
free(resolved_backup_dir);
}
}
if (!backup_path) {
size_t path_len = strlen(disk_path);
size_t suffix_len = strlen(backup_suffix);
backup_path = malloc(path_len + suffix_len + 1);
if (backup_path) {
memcpy(backup_path, disk_path, path_len);
memcpy(backup_path + path_len, backup_suffix, suffix_len + 1);
}
}
if (backup_path) {
char* backup_dir_path = str_dup(backup_path);
if (backup_dir_path) {
const char* bdir = dirname(backup_dir_path);
mkdir_r(bdir);
free(backup_dir_path);
}
if (!file_store_rename_secure(disk_path, backup_path)) {
free(backup_path);
free(resolved_root);
free(confined_backup);
free(confined_partial);
free(disk_path);
return false;
}
free(backup_path);
}
}
}
char* dir_dup = str_dup(disk_path);
if (!dir_dup) {
free(confined_backup);
free(confined_partial);
free(resolved_root);
free(disk_path);
return false;
}
char* dir_str = dirname(dir_dup);
if (!mkdir_r(dir_str)) {
free(dir_dup);
free(confined_backup);
free(confined_partial);
free(resolved_root);
free(disk_path);
return false;
}
char* resolved_dir = realpath(dir_str, NULL);
free(dir_dup);
if (resolved_dir == NULL) {
log_message(LOG_LEVEL_ERROR, "Failed to resolve directory for: %s", disk_path);
free(confined_backup);
free(confined_partial);
free(resolved_root);
free(disk_path);
return false;
}
size_t root_len = strlen(resolved_root);
if (strncmp(resolved_dir, resolved_root, root_len) != 0 ||
(resolved_dir[root_len] != '\0' && resolved_dir[root_len] != '/')) {
log_message(LOG_LEVEL_ERROR, "Path escape detected: %s is outside %s", disk_path, actual_root);
free(resolved_dir);
free(confined_backup);
free(confined_partial);
free(resolved_root);
free(disk_path);
return false;
}
free(resolved_dir);
free(resolved_root);
bool ok = file_store_write_secure(disk_path, file->data->data, file->data->size, inplace, sparse,
file->metadata);
free(confined_backup);
free(confined_partial);
free(disk_path);
return ok;
}
static File* receive_delta_file(int fd, const Config* config, const char* check_path,
void* old_data, unsigned long long old_size, bool* failed) {
if (!old_data)
return NULL;
DeltaSignature* sig = delta_signature_create(old_data, old_size, config->delta_block_size);
if (!sig) {
free(old_data);
*failed = true;
return NULL;
}
Data* sig_data = delta_signature_serialize(sig);
if (!sig_data) {
delta_signature_destroy(sig);
free(old_data);
*failed = true;
return NULL;
}
bool sig_sent = send_status(fd, STATUS_DELTA_SIGNATURE) && send_data(fd, sig_data);
data_destroy(sig_data);
if (!sig_sent) {
delta_signature_destroy(sig);
free(old_data);
*failed = true;
return NULL;
}
Status resp;
if (!receive_status(fd, &resp)) {
delta_signature_destroy(sig);
free(old_data);
*failed = true;
return NULL;
}
if (resp == STATUS_DELTA_DATA) {
Data* delta_data = receive_data(fd);
if (!delta_data) {
delta_signature_destroy(sig);
free(old_data);
*failed = true;
return NULL;
}
Data* raw_delta = delta_data;
if (config->use_compression) {
raw_delta = data_decompress(delta_data);
data_destroy(delta_data);
if (!raw_delta) {
free(old_data);
delta_signature_destroy(sig);
*failed = true;
return NULL;
}
}
Delta* delta = delta_deserialize(raw_delta);
data_destroy(raw_delta);
if (!delta) {
free(old_data);
delta_signature_destroy(sig);
*failed = true;
return NULL;
}
void* new_data = delta_apply(old_data, old_size, delta, config->delta_block_size);
uint64_t new_size = delta->new_file_size;
delta_destroy(delta);
if (!new_data) {
free(old_data);
delta_signature_destroy(sig);
*failed = true;
return NULL;
}
File* file = file_create(check_path);
if (!file) {
free(new_data);
free(old_data);
delta_signature_destroy(sig);
*failed = true;
return NULL;
}
if (config->use_metadata) {
int meta_ok = 1;
file->metadata = metadata_receive(fd, &meta_ok);
if (!meta_ok) {
file_destroy(file);
free(new_data);
free(old_data);
delta_signature_destroy(sig);
*failed = true;
return NULL;
}
}
data_destroy(file->data);
file->data = data_create(new_data, (size_t)new_size);
free(old_data);
delta_signature_destroy(sig);
return file;
}
if (resp == STATUS_NEXT) {
delta_signature_destroy(sig);
free(old_data);
File* file = file_create(check_path);
if (!file) {
*failed = true;
return NULL;
}
if (config->use_metadata) {
int meta_ok = 1;
file->metadata = metadata_receive(fd, &meta_ok);
if (!meta_ok) {
file_destroy(file);
*failed = true;
return NULL;
}
}
Data* file_data = receive_data(fd);
if (file_data == NULL) {
file_destroy(file);
*failed = true;
return NULL;
}
if (config->use_compression) {
Data* uncompressed = data_decompress(file_data);
data_destroy(file_data);
if (uncompressed == NULL) {
file_destroy(file);
*failed = true;
return NULL;
}
file_data = uncompressed;
}
data_destroy(file->data);
file->data = file_data;
return file;
}
delta_signature_destroy(sig);
free(old_data);
*failed = true;
return NULL;
}
File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
*skipped = false;
char* check_path = receive_str(fd);
if (check_path == NULL) {
return NULL;
}
unsigned long long check_size;
long long check_mtime;
uint64_t check_checksum = 0;
if (!receive_n_data(fd, &check_size, sizeof(check_size)) ||
!receive_n_data(fd, &check_mtime, sizeof(check_mtime))) {
free(check_path);
return NULL;
}
if (config->checksum && !receive_n_data(fd, &check_checksum, sizeof(check_checksum))) {
free(check_path);
return NULL;
}
if (has_path_traversal(check_path)) {
log_message(LOG_LEVEL_ERROR, "Path traversal detected: %s", check_path);
free(check_path);
return NULL;
}
char* full_path = path_cat(config->receive_root_directory, check_path);
struct stat st;
bool has_old_file = false;
int old_fd = -1;
if (full_path) {
char* leaf = NULL;
int parent_fd = file_store_open_secure_parent(full_path, &leaf);
if (parent_fd >= 0) {
old_fd = openat(parent_fd, leaf, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
free(leaf);
close(parent_fd);
has_old_file = old_fd >= 0 && fstat(old_fd, &st) == 0 && S_ISREG(st.st_mode);
}
}
unsigned long long old_size = has_old_file ? (unsigned long long)st.st_size : 0;
void* old_data = NULL;
if (has_old_file && old_size > 0) {
old_data = malloc((size_t)old_size);
if (old_data) {
size_t got = 0;
while (got < (size_t)old_size) {
ssize_t n = read(old_fd, (char*)old_data + got, (size_t)old_size - got);
if (n <= 0) {
free(old_data);
old_data = NULL;
break;
}
got += (size_t)n;
}
}
}
if (old_fd >= 0) {
close(old_fd);
}
bool match = has_old_file && (unsigned long long)st.st_size == check_size;
if (match && config->checksum) {
uint64_t old_checksum = old_size == 0 ? delta_xxhash64("", 0) : 0;
if (old_data)
old_checksum = delta_xxhash64(old_data, (size_t)old_size);
match = (old_size == 0 || old_data) && old_checksum == check_checksum;
free(old_data);
old_data = NULL;
} else if (match) {
match = (long long)st.st_mtime == check_mtime;
}
if (match) {
free(old_data);
if (!send_status(fd, STATUS_OK)) {
free(full_path);
free(check_path);
return NULL;
}
free(full_path);
free(check_path);
*skipped = true;
return NULL;
}
bool try_delta = config->use_delta && has_old_file &&
delta_should_attempt(old_size, check_size, config->delta_max_file_size);
if (try_delta) {
bool delta_failed = false;
File* delta_file =
receive_delta_file(fd, config, check_path, old_data, old_size, &delta_failed);
old_data = NULL; /* receive_delta_file consumes the snapshot on every path */
if (delta_file) {
free(full_path);
free(check_path);
return delta_file;
}
if (delta_failed) {
free(full_path);
free(check_path);
return NULL;
}
free(old_data);
old_data = NULL;
try_delta = false;
}
if (!try_delta) {
if (!send_status(fd, STATUS_NEXT)) {
free(full_path);
free(check_path);
return NULL;
}
}
File* file = file_create(check_path);
free(check_path);
free(full_path);
if (file == NULL) {
return NULL;
}
if (config->use_metadata) {
int meta_ok = 1;
file->metadata = metadata_receive(fd, &meta_ok);
if (!meta_ok) {
file_destroy(file);
return NULL;
}
}
Data* file_data = receive_data(fd);
if (file_data == NULL) {
file_destroy(file);
return NULL;
}
if (config->use_compression) {
Data* uncompressed = data_decompress(file_data);
data_destroy(file_data);
if (uncompressed == NULL) {
file_destroy(file);
return NULL;
}
file_data = uncompressed;
}
data_destroy(file->data);
file->data = file_data;
return file;
}
File* file_receive(const Config* config, int file_descriptor) {
char* path = receive_str(file_descriptor);
if (path == NULL)
return NULL;
if (path[0] == '\0' || has_path_traversal(path)) {
log_message(LOG_LEVEL_ERROR, "Invalid received file path: %s", path);
free(path);
return NULL;
}
File* file = file_create(path);
free(path);
if (file == NULL)
return NULL;
if (config->use_metadata) {
int meta_ok = 1;
file->metadata = metadata_receive(file_descriptor, &meta_ok);
if (!meta_ok) {
file_destroy(file);
return NULL;
}
}
Data* file_data = receive_data(file_descriptor);
if (file_data == NULL) {
file_destroy(file);
return NULL;
}
if (config->use_compression) {
Data* file_data_uncompressed = data_decompress(file_data);
data_destroy(file_data);
if (file_data_uncompressed == NULL) {
file_destroy(file);
return NULL;
}
file_data = file_data_uncompressed;
}
data_destroy(file->data);
file->data = file_data;
return file;
}
int receive_manifest(int fd, const Config* config, int* next_status) {
int received_status = STATUS_ERROR;
int* status_out = next_status ? next_status : &received_status;
int count;
if (!receive_int(fd, &count))
return -1;
if (count < 0 || count > MAX_MANIFEST_ENTRIES)
return -1;
ArrayList* manifest = array_list_create(free);
if (!manifest)
return -1;
size_t manifest_bytes = 0;
for (int i = 0; i < count; i++) {
char* s = receive_str(fd);
size_t entry_size = s ? strlen(s) : 0;
if (!s || s[0] == '\0' || s[0] == '/' || has_path_traversal(s) ||
entry_size > MAX_MANIFEST_BYTES - manifest_bytes ||
(manifest_bytes += entry_size) > MAX_MANIFEST_BYTES || !array_list_add(manifest, s)) {
free(s);
array_list_delete(manifest);
return -1;
}
}
if (!receive_status(fd, status_out)) {
array_list_delete(manifest);
return -1;
}
/* Deletion is a commit operation: never perform it until the sender has
completed the manifest frame successfully. */
if (*status_out != STATUS_FINISHED || !config->use_delete) {
array_list_delete(manifest);
return *status_out == STATUS_FINISHED ? 0 : -1;
}
fprintf(stderr, "Deleting files not in manifest...\n");
bool deletion_ok = delete_extras(config->receive_root_directory, manifest);
array_list_delete(manifest);
return deletion_ok ? 0 : -1;
}