Add executability preservation option

src/client/client_cli.c

@@ -287,6 +287,10 @@ int parse_args(Config* config, int argc, char* argv[], int* positional_args,
     } else if (opt_is(argv[i], "-M", "--preserve")) {
       config->use_metadata = true;
       log_message(LOG_LEVEL_INFO, "Enabled metadata preservation");
+    } else if (opt_is(argv[i], "-E", "--executability")) {
+      config->use_metadata = true;
+      config->use_executability = true;
+      log_message(LOG_LEVEL_INFO, "Enabled executable permission preservation");
     } else if (opt_is(argv[i], "-f", "--sendfile")) {
       config->use_sendfile = true;
       log_message(LOG_LEVEL_INFO, "Enabled sendfile");
@@ -490,7 +494,6 @@ int main(int argc, char* argv[]) {
     log_message(LOG_LEVEL_INFO, "Enabling metadata preservation for --delta");
     config->use_metadata = true;
   }
-
   /* Initialize TLS if needed */
   if (config->use_tls)
     tls_global_init();

src/client/usage.c

@@ -38,6 +38,7 @@ void print_usage(void) {
   printf("  -f                  Enable sendfile (TCP only, not with -c or -s)\n");
   printf("  -v, --verbose       Enable debug logging\n");
   printf("  -M, --preserve      Preserve file metadata\n");
+  printf("  -E, --executability Preserve executable permission bits\n");
   printf("  --chunk-size <n>    Chunk size in bytes (default: %d)\n", DEFAULT_CHUNK_SIZE);
   printf("  --source-dir <path> Source directory\n");
   printf("  --dest-dir <path>   Destination directory\n");

src/shared/config.c

@@ -17,6 +17,7 @@ static void config_set_defaults(Config* config) {
   config->use_chunk_serialization = false;
   config->use_compression = false;
   config->use_metadata = false;
+  config->use_executability = false;
   config->show_progress = false;
   config->dry_run = false;
   config->use_delete = false;
@@ -116,11 +117,11 @@ static bool validate_received_config(const Config* config) {
   return valid_wire_bool(config->save_to_disk) && valid_wire_bool(config->use_multithreading) &&
          valid_wire_bool(config->use_chunk_serialization) &&
          valid_wire_bool(config->use_compression) && valid_wire_bool(config->use_metadata) &&
-         valid_wire_bool(config->use_sendfile) && valid_wire_bool(config->use_delete) &&
-         valid_wire_bool(config->use_incremental) && valid_wire_bool(config->use_delta) &&
-         valid_wire_bool(config->backup) && valid_wire_bool(config->follow_symlinks) &&
-         valid_wire_bool(config->copy_links) && valid_wire_bool(config->safe_links) &&
-         valid_wire_bool(config->copy_unsafe_links) &&
+         valid_wire_bool(config->use_executability) && valid_wire_bool(config->use_sendfile) &&
+         valid_wire_bool(config->use_delete) && valid_wire_bool(config->use_incremental) &&
+         valid_wire_bool(config->use_delta) && valid_wire_bool(config->backup) &&
+         valid_wire_bool(config->follow_symlinks) && valid_wire_bool(config->copy_links) &&
+         valid_wire_bool(config->safe_links) && valid_wire_bool(config->copy_unsafe_links) &&
          valid_wire_bool(config->preserve_hard_links) && valid_wire_bool(config->preserve_acls) &&
          valid_wire_bool(config->preserve_xattrs) && valid_wire_bool(config->preserve_devices) &&
          valid_wire_bool(config->preserve_sparse) && valid_wire_bool(config->update) &&
@@ -222,7 +223,7 @@ static bool send_core_fields(int fd, const Config* c) {
          send_str(fd, c->receive_root_directory) && send_int(fd, c->save_to_disk) &&
          send_int(fd, c->use_multithreading) && send_int(fd, c->use_chunk_serialization) &&
          send_int(fd, c->use_compression) && send_int(fd, c->use_metadata) &&
-         send_int(fd, c->compression_level) &&
+         send_int(fd, c->use_executability) && send_int(fd, c->compression_level) &&
          send_n_data(fd, &c->chunk_size, sizeof(c->chunk_size)) && send_int(fd, c->use_sendfile);
 }
 
@@ -264,7 +265,8 @@ static bool receive_core_fields(int fd, Config* c) {
     return false;
   if (!receive_wire_bool(fd, &c->save_to_disk) || !receive_wire_bool(fd, &c->use_multithreading) ||
       !receive_wire_bool(fd, &c->use_chunk_serialization) ||
-      !receive_wire_bool(fd, &c->use_compression) || !receive_wire_bool(fd, &c->use_metadata))
+      !receive_wire_bool(fd, &c->use_compression) || !receive_wire_bool(fd, &c->use_metadata) ||
+      !receive_wire_bool(fd, &c->use_executability))
     return false;
   if (!receive_int(fd, &value))
     return false;

src/shared/config.h

@@ -18,6 +18,7 @@ typedef struct Config {
   bool use_compression;
   bool use_sendfile;
   bool use_metadata;
+  bool use_executability;
   bool show_progress;
   bool dry_run;
   bool use_delete;
@@ -128,7 +129,7 @@ typedef struct Config {
   char* compress_choice;
 } Config;
 
-#define PROTOCOL_VERSION "2.2.0"
+#define PROTOCOL_VERSION "2.3.0"
 #define DEFAULT_CHUNK_SIZE (10 * 1024 * 1024)
 
 Config* config_create(void);

src/shared/file.c

@@ -303,7 +303,8 @@ bool file_rename_secure(const char* old_path, const char* new_path) {
 }
 
 bool file_to_disk_secure(const char* path, const void* data, unsigned long long data_size,
-                         bool inplace, bool sparse, const FileMetadata* metadata) {
+                         bool inplace, bool sparse, const FileMetadata* metadata,
+                         bool preserve_executability) {
   char* leaf = NULL;
   int dirfd = file_open_secure_parent(path, &leaf, true);
   if (dirfd < 0)
@@ -316,7 +317,7 @@ bool file_to_disk_secure(const char* path, const void* data, unsigned long long
       if (!sparse || data_size == 0 || ftruncate(fd, (off_t)data_size) == 0)
         ok = write_all(fd, data, data_size);
       if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, metadata);
+        ok = file_restore_metadata_fd(fd, metadata, preserve_executability);
     }
   } else {
     char tmp[NAME_MAX];
@@ -330,7 +331,7 @@ bool file_to_disk_secure(const char* path, const void* data, unsigned long long
       if (ok || (!sparse || data_size == 0))
         ok = write_all(fd, data, data_size);
       if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, metadata);
+        ok = file_restore_metadata_fd(fd, metadata, preserve_executability);
       if (close(fd) != 0)
         ok = false;
       fd = -1;
@@ -351,5 +352,5 @@ bool file_write_to_disk(const char* path, const void* data, unsigned long long d
                         bool inplace, bool sparse) {
   if (!path || (!data && data_size != 0) || has_path_traversal(path))
     return false;
-  return file_to_disk_secure(path, data, data_size, inplace, sparse, NULL);
+  return file_to_disk_secure(path, data, data_size, inplace, sparse, NULL, false);
 }

src/shared/file.h

@@ -31,6 +31,7 @@ int file_open_secure_parent(const char* path, char** leaf_out, bool create_dirs)
 bool file_ensure_directory_secure(const char* path);
 bool file_rename_secure(const char* old_path, const char* new_path);
 bool file_to_disk_secure(const char* path, const void* data, unsigned long long data_size,
-                         bool inplace, bool sparse, const FileMetadata* metadata);
+                         bool inplace, bool sparse, const FileMetadata* metadata,
+                         bool preserve_executability);
 
 #endif

src/shared/file_receive.c

@@ -25,6 +25,7 @@ bool file_save_to_disk(const char* root_directory, const File* file, const Confi
   bool backup_enabled = config && config->backup;
   bool inplace = config && config->inplace;
   bool sparse = config && config->preserve_sparse;
+  bool preserve_executability = config && config->use_executability;
   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;
@@ -104,7 +105,7 @@ bool file_save_to_disk(const char* root_directory, const File* file, const Confi
   }
 
   bool ok = file_to_disk_secure(disk_path, file->data->data, file->data->size, inplace, sparse,
-                                file->metadata);
+                                file->metadata, preserve_executability);
   free(parent_copy);
   free(backup_path);
   free(confined_backup);

src/shared/file_store.c

@@ -140,7 +140,8 @@ static bool write_all(int fd, const void* data, unsigned long long size) {
 }
 
 bool file_store_write_secure(const char* path, const void* data, unsigned long long data_size,
-                             bool inplace, bool sparse, const FileMetadata* metadata) {
+                             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)
@@ -153,7 +154,7 @@ bool file_store_write_secure(const char* path, const void* data, unsigned long l
       if (!sparse || data_size == 0 || ftruncate(fd, (off_t)data_size) == 0)
         ok = write_all(fd, data, data_size);
       if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, 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);
@@ -178,7 +179,7 @@ bool file_store_write_secure(const char* path, const void* data, unsigned long l
       if (ok || (!sparse || data_size == 0))
         ok = write_all(fd, data, data_size);
       if (ok && metadata)
-        ok = file_restore_metadata_fd(fd, metadata);
+        ok = file_restore_metadata_fd(fd, metadata, preserve_executability);
       if (close(fd) != 0)
         ok = false;
       fd = -1;

src/shared/file_store.h

@@ -8,6 +8,7 @@ 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 inplace, bool sparse, const FileMetadata* metadata,
+                             bool preserve_executability);
 
 #endif

src/shared/metadata.c

@@ -179,10 +179,21 @@ FileMetadata* metadata_receive(int file_descriptor, int* ok) {
   return m;
 }
 
-void file_restore_metadata(const char* path, const FileMetadata* metadata) {
+static mode_t metadata_mode(const FileMetadata* metadata, mode_t current_mode,
+                            bool preserve_executability) {
+  const mode_t execute_bits = S_IXUSR | S_IXGRP | S_IXOTH;
+  if (preserve_executability)
+    return (current_mode & 0777 & ~execute_bits) | (metadata->mode & execute_bits);
+  return metadata->mode & 0777 & ~(S_IWGRP | S_IWOTH);
+}
+
+void file_restore_metadata(const char* path, const FileMetadata* metadata,
+                           bool preserve_executability) {
   if (metadata == NULL)
     return;
-  mode_t safe_mode = metadata->mode & 0777 & ~(S_IWGRP | S_IWOTH);
+  struct stat current;
+  mode_t current_mode = stat(path, &current) == 0 ? current.st_mode : 0;
+  mode_t safe_mode = metadata_mode(metadata, current_mode, preserve_executability);
   if (chmod(path, safe_mode) != 0)
     log_message(LOG_LEVEL_WARNING, "Failed to chmod %s: %s", path, strerror(errno));
   /* Never apply client-supplied ownership.  The descriptor API below is the
@@ -196,11 +207,14 @@ void file_restore_metadata(const char* path, const FileMetadata* metadata) {
     log_message(LOG_LEVEL_WARNING, "Failed to set timestamps on %s: %s", path, strerror(errno));
 }
 
-bool file_restore_metadata_fd(int fd, const FileMetadata* metadata) {
+bool file_restore_metadata_fd(int fd, const FileMetadata* metadata, bool preserve_executability) {
   if (fd < 0 || metadata == NULL)
     return metadata == NULL;
   bool ok = true;
-  mode_t safe_mode = metadata->mode & 0777 & ~(S_IWGRP | S_IWOTH);
+  struct stat current;
+  if (fstat(fd, &current) != 0)
+    return false;
+  mode_t safe_mode = metadata_mode(metadata, current.st_mode, preserve_executability);
   if (fchmod(fd, safe_mode) != 0)
     ok = false;
   /* Client uid/gid values are deliberately not authoritative. */

src/shared/metadata.h

@@ -29,7 +29,8 @@ void metadata_to_buf(char** buf, const FileMetadata* m);
 FileMetadata* metadata_from_buf(char** buf);
 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);
-bool file_restore_metadata_fd(int fd, const FileMetadata* metadata);
+void file_restore_metadata(const char* path, const FileMetadata* metadata,
+                           bool preserve_executability);
+bool file_restore_metadata_fd(int fd, const FileMetadata* metadata, bool preserve_executability);
 
 #endif