refactor: remove dead file_store subsystem and unused wrappers

src/shared/compression.c

@@ -17,10 +17,6 @@
 static char* SKIP_COMPRESSION_EXTENSIONS[] = {".jpg", ".jpeg", ".png", ".gif", ".mp4", ".mkv",
                                               ".zip", ".gz",   ".xz",  ".zst", NULL};
 
-bool compression_should_skip(const char* path) {
-  return compression_should_skip_with_suffixes(path, NULL, -1);
-}
-
 bool compression_should_skip_with_suffixes(const char* path, char* const* suffixes, int count) {
   if (!path)
     return false;

src/shared/compression.h

@@ -11,7 +11,6 @@ Data* data_compress_with_threads(Data* data_to_compress, int compression_level,
                                  int compression_threads);
 Data* data_decompress(Data* compressed_data);
 Data* data_decompress_limited(Data* compressed_data, size_t maximum_size);
-bool compression_should_skip(const char* path);
 bool compression_should_skip_with_suffixes(const char* path, char* const* suffixes, int count);
 
 /* Release the calling thread's cached zstd contexts (compressor, decompressor

src/shared/file.c

@@ -287,11 +287,6 @@ size_t file_content_to_buffer(File* file) {
 static int authorized_root_fd = -1;
 static char* authorized_root_path;
 
-static bool path_is_within_root(const char* root, const char* path) {
-  size_t root_len = strlen(root);
-  return strncmp(root, path, root_len) == 0 && (path[root_len] == '\0' || path[root_len] == '/');
-}
-
 bool file_set_authorized_root(int fd, const char* canonical_path) {
   char* path_copy = canonical_path ? str_dup(canonical_path) : NULL;
   if (canonical_path && !path_copy) {
@@ -362,10 +357,6 @@ void file_set_keep_dirlinks(bool enable) {
   file_keep_dirlinks = enable;
 }
 
-bool file_get_keep_dirlinks(void) {
-  return file_keep_dirlinks;
-}
-
 /* --trust-sender (Phase 5) receiver process-wide policy: when set, the receiver
  * trusts the sender's file list and skips its own redundant up-front re-
  * validation (empty/".." path rejection, escaping-symlink-target containment).

src/shared/file.h

@@ -52,7 +52,6 @@ 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);
-bool file_get_keep_dirlinks(void);
 
 /* --trust-sender receiver process-wide policy (Phase 5).  When set, the
  * receiver trusts that the sender already produced a clean file list and skips

src/shared/file_store.c

@@ -1,129 +1,7 @@
 #include <errno.h>
-#include <fcntl.h>
-#include <libgen.h>
-#include <limits.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 
 #include "file_store.h"
-#include "metadata.h"
-#include "utils.h"
-
-static int authorized_root_fd = -1;
-static char* authorized_root_path;
-
-static bool path_is_within_root(const char* root, const char* path) {
-  size_t root_length = strlen(root);
-  return strncmp(root, path, root_length) == 0 &&
-         (path[root_length] == '\0' || path[root_length] == '/');
-}
-
-bool file_store_set_authorized_root(int fd, const char* canonical_path) {
-  char* new_path = canonical_path ? str_dup(canonical_path) : NULL;
-  if (canonical_path && !new_path) {
-    authorized_root_fd = -1;
-    free(authorized_root_path);
-    authorized_root_path = NULL;
-    return false;
-  }
-  free(authorized_root_path);
-  authorized_root_path = new_path;
-  authorized_root_fd = fd;
-  return true;
-}
-
-int file_store_open_secure_parent(const char* path, char** leaf_out) {
-  char* copy = str_dup(path);
-  if (!copy)
-    return -1;
-  char* parent = dirname(copy);
-  const char* slash = strrchr(path, '/');
-  char* leaf = str_dup(slash ? slash + 1 : path);
-  if (!leaf) {
-    free(copy);
-    return -1;
-  }
-  int fd;
-  if (authorized_root_fd >= 0) {
-    if (!authorized_root_path || path[0] != '/' ||
-        !path_is_within_root(authorized_root_path, path)) {
-      free(copy);
-      free(leaf);
-      return -1;
-    }
-    fd = dup(authorized_root_fd);
-    if (fd < 0) {
-      free(copy);
-      free(leaf);
-      return -1;
-    }
-    size_t root_length = strlen(authorized_root_path);
-    char* relative = str_dup(path + root_length);
-    if (!relative) {
-      free(copy);
-      free(leaf);
-      close(fd);
-      return -1;
-    }
-    free(copy);
-    copy = relative;
-    parent = dirname(copy);
-  } else {
-    fd = (parent[0] == '/') ? open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)
-                            : open(".", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
-  }
-  if (fd < 0) {
-    free(copy);
-    free(leaf);
-    return -1;
-  }
-  char* save = NULL;
-  char* component = strtok_r(parent, "/", &save);
-  while (component) {
-    if (strcmp(component, "..") == 0) {
-      close(fd);
-      free(copy);
-      free(leaf);
-      return -1;
-    }
-    if (strcmp(component, ".") != 0) {
-      int next = openat(fd, component, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
-      if (next < 0 && errno == ENOENT) {
-        if (mkdirat(fd, component, 0755) == 0 || errno == EEXIST)
-          next = openat(fd, component, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
-      }
-      if (next < 0) {
-        close(fd);
-        free(copy);
-        free(leaf);
-        return -1;
-      }
-      close(fd);
-      fd = next;
-    }
-    component = strtok_r(NULL, "/", &save);
-  }
-  free(copy);
-  *leaf_out = leaf;
-  return fd;
-}
-
-bool file_store_rename_secure(const char* old_path, const char* new_path) {
-  char *old_leaf = NULL, *new_leaf = NULL;
-  int old_parent = file_store_open_secure_parent(old_path, &old_leaf);
-  int new_parent = file_store_open_secure_parent(new_path, &new_leaf);
-  bool ok = old_parent >= 0 && new_parent >= 0 &&
-            renameat(old_parent, old_leaf, new_parent, new_leaf) == 0;
-  if (old_parent >= 0)
-    close(old_parent);
-  if (new_parent >= 0)
-    close(new_parent);
-  free(old_leaf);
-  free(new_leaf);
-  return ok;
-}
 
 static bool write_all(int fd, const void* data, unsigned long long size) {
   const unsigned char* p = data;
@@ -176,67 +54,3 @@ bool file_store_write_sparse(int fd, const unsigned char* data, unsigned long lo
   }
   return ftruncate(fd, (off_t)size) == 0;
 }
-
-bool file_store_write_secure(const char* path, const void* data, unsigned long long data_size,
-                             bool inplace, bool sparse, const FileMetadata* metadata,
-                             bool preserve_executability) {
-  char* leaf = NULL;
-  int dirfd = file_store_open_secure_parent(path, &leaf);
-  if (dirfd < 0)
-    return false;
-  int fd = -1;
-  bool ok = false;
-  if (inplace) {
-    fd = openat(dirfd, leaf, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW, 0644);
-    if (fd >= 0) {
-      if (sparse && data_size > 0) {
-        if (ftruncate(fd, (off_t)data_size) == 0)
-          ok = file_store_write_sparse(fd, data, data_size);
-      } else {
-        ok = write_all(fd, data, data_size);
-      }
-      if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, metadata, preserve_executability);
-    }
-  } else {
-    int tmp_size = snprintf(NULL, 0, ".%s.tmp.%ld.%u", leaf, (long)getpid(), 99U);
-    if (tmp_size < 0) {
-      close(dirfd);
-      free(leaf);
-      return false;
-    }
-    char* tmp = malloc((size_t)tmp_size + 1);
-    if (!tmp) {
-      close(dirfd);
-      free(leaf);
-      return false;
-    }
-    for (unsigned int i = 0; i < 100 && !ok; ++i) {
-      snprintf(tmp, (size_t)tmp_size + 1, ".%s.tmp.%ld.%u", leaf, (long)getpid(), i);
-      fd = openat(dirfd, tmp, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC | O_NOFOLLOW, 0600);
-      if (fd < 0)
-        continue;
-      if (sparse && data_size > 0)
-        ok = ftruncate(fd, (off_t)data_size) == 0;
-      if (ok || (!sparse || data_size == 0))
-        ok = (sparse && data_size > 0)
-                 ? file_store_write_sparse(fd, (const unsigned char*)data, data_size)
-                 : write_all(fd, data, data_size);
-      if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, metadata, preserve_executability);
-      if (close(fd) != 0)
-        ok = false;
-      fd = -1;
-      if (ok && renameat(dirfd, tmp, dirfd, leaf) != 0)
-        ok = false;
-      if (!ok)
-        unlinkat(dirfd, tmp, 0);
-    }
-    free(tmp);
-  }
-  if (fd >= 0)
-    close(fd);
-  close(dirfd);
-  free(leaf);
-  return ok;
-}

src/shared/file_store.h

@@ -1,15 +1,8 @@
 #ifndef FILE_STORE_H
 #define FILE_STORE_H
 
-#include "file.h"
 #include <stdbool.h>
 
-bool file_store_set_authorized_root(int fd, const char* canonical_path);
-int file_store_open_secure_parent(const char* path, char** leaf_out);
-bool file_store_rename_secure(const char* old_path, const char* new_path);
-bool file_store_write_secure(const char* path, const void* data, unsigned long long data_size,
-                             bool inplace, bool sparse, const FileMetadata* metadata,
-                             bool preserve_executability);
 /* Sparse-aware write (--sparse/-S): every all-zero run of at least
  * SPARSE_HOLE_MIN bytes is skipped with lseek(SEEK_CUR) so it becomes a real
  * hole; every other byte is written.  The caller pre-sizes the file with

src/shared/protocol.c

@@ -570,10 +570,6 @@ Data* protocol_receive_data_limited(ProtocolSession* session, unsigned long long
   return result;
 }
 
-Data* protocol_receive_data(ProtocolSession* session) {
-  return protocol_receive_data_limited(session, MAX_DATA_PAYLOAD_SIZE);
-}
-
 bool protocol_send_int(ProtocolSession* session, int data) {
   if (!protocol_send_n_data(session, &data, sizeof(int)))
     return false;

src/shared/protocol.h

@@ -172,7 +172,6 @@ char* protocol_receive_str(ProtocolSession* session);
 bool protocol_send_str_redacted(ProtocolSession* session, const char* data);
 char* protocol_receive_str_redacted(ProtocolSession* session);
 bool protocol_send_data(ProtocolSession* session, const Data* data);
-Data* protocol_receive_data(ProtocolSession* session);
 Data* protocol_receive_data_limited(ProtocolSession* session, unsigned long long maximum_size);
 bool protocol_send_int(ProtocolSession* session, int data);
 bool protocol_receive_int(ProtocolSession* session, int* data);

src/shared/transport_tcp.c

@@ -440,10 +440,6 @@ bool tcp_connect_socket_ex(Client* client, const char* host, int port,
   return true;
 }
 
-bool tcp_connect_socket(Client* client, const char* host, int port) {
-  return tcp_connect_socket_ex(client, host, port, NULL);
-}
-
 bool client_connect_ex(Client* client, const char* host, int port, const TcpConnectOptions* opts) {
   if (!tcp_connect_socket_ex(client, host, port, opts))
     return false;

src/shared/transport_tcp.h

@@ -57,7 +57,6 @@ bool client_connect_ex(Client* client, const char* host, int port, const TcpConn
 bool client_connect(Client* client, const char* host, int port);
 bool tcp_connect_socket_ex(Client* client, const char* host, int port,
                            const TcpConnectOptions* opts);
-bool tcp_connect_socket(Client* client, const char* host, int port);
 void client_disconnect(Client* client);
 void client_delete(Client* client);
 void tcp_set_timeouts(int timeout_sec, int contimeout_sec);

src/shared/utils.c

@@ -36,11 +36,19 @@ void utils_set_authorized_root_fd(int fd) {
   (void)utils_set_authorized_root(fd, NULL);
 }
 
-static bool path_is_within_root(const char* root, const char* path) {
+bool path_is_within_root(const char* root, const char* path) {
   size_t root_len = strlen(root);
   return strncmp(root, path, root_len) == 0 && (path[root_len] == '\0' || path[root_len] == '/');
 }
 
+/* Open the destination root directory itself, confined to the authorized root.
+ * NOTE (do not merge with file_open_secure_parent): this walk opens dest_root
+ * (a directory that must already exist) and returns its fd, whereas
+ * file_open_secure_parent resolves the PARENT of a file path, optionally
+ * creating missing components and honouring --keep-dirlinks / --copy-as.  The
+ * two differ in create-vs-no-create, in what path component they stop at, and
+ * in the extra receiver policies they apply, so they are intentionally kept
+ * separate.  Both rely on the shared lexical path_is_within_root check. */
 static int open_authorized_destination(const char* dest_root) {
   if (authorized_root_fd < 0 || !authorized_root_path || !dest_root ||
       !path_is_within_root(authorized_root_path, dest_root))

src/shared/utils.h

@@ -127,6 +127,12 @@ bool utils_set_authorized_root(int fd, const char* canonical_path);
 /* The fd-only compatibility form is fail-closed for path-based operations;
  * callers should use utils_set_authorized_root with the canonical identity. */
 void utils_set_authorized_root_fd(int fd);
+/* True when `path` is `root` itself or lies directly beneath it: a lexical
+ * prefix test requiring the byte after `root` to be '\0' or '/'.  Both `root`
+ * and `path` must be absolute canonical paths free of "."/".." components (the
+ * callers guarantee this); this is containment by string, not by resolved
+ * symlinks.  Shared by the utils and file secure-walk root confinement. */
+bool path_is_within_root(const char* root, const char* path);
 bool has_path_traversal(const char* path);
 bool utils_valid_batch_path(const char* path);
 bool format_human_bytes(unsigned long long bytes, char* buffer, size_t buffer_size);

tests/test_file.c

@@ -3,7 +3,6 @@
 #endif
 #include "test_file.h"
 #include "file.h"
-#include "file_store.h"
 #include "file_receive.h"
 #include "data.h"
 #include "config.h"
@@ -1225,7 +1224,7 @@ void test_trust_sender() {
 }
 
 /* --sparse/-S hole preservation: a buffer with a long zero run written via
- * file_store_write_secure(sparse=true) must round-trip its content exactly and
+ * file_to_disk_secure(sparse=true) must round-trip its content exactly and
  * have the right logical size, and should additionally be genuinely sparse on
  * filesystems that support holes.  The sparseness assertion is tolerant: if the
  * filesystem reports no holes (SEEK_HOLE/SEEK_DATA -> ENXIO) we skip the strict
@@ -1247,7 +1246,7 @@ static void test_file_write_to_disk_sparse_preserves_holes() {
     buf[size - 1 - i] = (unsigned char)((i * 7) % 253);
   }
 
-  EXPECT_TRUE(file_store_write_secure(path, buf, size, false, true, NULL, false));
+  EXPECT_TRUE(file_to_disk_secure(path, buf, size, false, true, false, NULL, false, NULL));
 
   /* Logical size must equal data_size exactly. */
   struct stat st;