merge: resolve conflict with dev, apply helpers to new options

- Add set_string_option(), set_positive_int_option(), set_nonneg_int_option()
  helpers to eliminate duplicated alloc/free/assign patterns
- Replace 14 string-option branches with set_string_option() calls
- Replace 7 integer-option branches with set_positive/nonneg_int_option()
- Fix --info/--debug: replace atoi() with validated parse
- Fix --max-size/--min-size: add strtoull() error checking
- Fix --chunk-size: validate input with error message on failure

src/client/client_cli.c

@@ -49,6 +49,37 @@ static bool parse_nonneg_int(const char* s, int* out_val) {
   return true;
 }
 
+/* Duplicate a string argument into *dest, freeing the old value. Returns 0 on success, -1 on
+ * failure. */
+static int set_string_option(char** dest, const char* value, const char* option_name) {
+  char* dup = str_dup(value);
+  if (!dup) {
+    fprintf(stderr, "Error: memory allocation failed for %s\n", option_name);
+    return -1;
+  }
+  free(*dest);
+  *dest = dup;
+  return 0;
+}
+
+/* Parse a string as a positive integer into *dest. Returns 0 on success, -1 on error. */
+static int set_positive_int_option(int* dest, const char* value, const char* option_name) {
+  if (!parse_positive_int(value, dest)) {
+    fprintf(stderr, "Error: %s must be a positive integer\n", option_name);
+    return -1;
+  }
+  return 0;
+}
+
+/* Parse a string as a non-negative integer into *dest. Returns 0 on success, -1 on error. */
+static int set_nonneg_int_option(int* dest, const char* value, const char* option_name) {
+  if (!parse_nonneg_int(value, dest)) {
+    fprintf(stderr, "Error: %s must be a non-negative integer\n", option_name);
+    return -1;
+  }
+  return 0;
+}
+
 static void print_usage(void);
 static int read_patterns_from_file(const char* filepath, char*** patterns, int* count);
 
@@ -100,9 +131,23 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       }
       config->include_patterns[config->include_count++] = dup;
     } else if (strcmp(argv[i], "--max-size") == 0 && i + 1 < argc) {
-      config->max_size = strtoull(argv[++i], NULL, 10);
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --max-size must be a non-negative integer\n");
+        return -1;
+      }
+      config->max_size = val;
     } else if (strcmp(argv[i], "--min-size") == 0 && i + 1 < argc) {
-      config->min_size = strtoull(argv[++i], NULL, 10);
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --min-size must be a non-negative integer\n");
+        return -1;
+      }
+      config->min_size = val;
     } else if (strcmp(argv[i], "--incremental") == 0) {
       config->use_incremental = true;
     } else if (strcmp(argv[i], "--delta") == 0) {
@@ -132,21 +177,11 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
         }
       }
     } else if (strcmp(argv[i], "--source-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --source-dir\n");
+      if (set_string_option(&config->send_directory, argv[++i], "--source-dir") != 0)
         return -1;
-      }
-      free(config->send_directory);
-      config->send_directory = dup;
     } else if (strcmp(argv[i], "--dest-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --dest-dir\n");
+      if (set_string_option(&config->receive_root_directory, argv[++i], "--dest-dir") != 0)
         return -1;
-      }
-      free(config->receive_root_directory);
-      config->receive_root_directory = dup;
     } else if (strcmp(argv[i], "--save-to-disk") == 0) {
       config->save_to_disk = true;
     } else if (strcmp(argv[i], "-M") == 0 || strcmp(argv[i], "--preserve") == 0) {
@@ -162,13 +197,8 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       config->use_chunk_serialization = true;
       log_message(LOG_LEVEL_INFO, "Enabled Chunk Serialization");
     } else if (strcmp(argv[i], "--server-host") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --server-host\n");
+      if (set_string_option(&config->server_host, argv[++i], "--server-host") != 0)
         return -1;
-      }
-      free(config->server_host);
-      config->server_host = dup;
     } else if (strcmp(argv[i], "--server-port") == 0 && i + 1 < argc) {
       if (!parse_positive_int(argv[++i], &config->server_port)) {
         fprintf(stderr, "Error: invalid --server-port value: %s\n", argv[i]);
@@ -191,69 +221,44 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "--progress") == 0) {
       config->show_progress = true;
     } else if (strcmp(argv[i], "--chunk-size") == 0 && i + 1 < argc) {
-      unsigned long long val = strtoull(argv[++i], NULL, 10);
-      if (val > 0)
-        config->chunk_size = val;
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0' || val == 0) {
+        fprintf(stderr, "Error: --chunk-size must be a positive integer\n");
+        return -1;
+      }
+      config->chunk_size = val;
     } else if (strcmp(argv[i], "--tls") == 0) {
       config->use_tls = true;
     } else if (strcmp(argv[i], "--cert") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --cert\n");
+      if (set_string_option(&config->tls_cert, argv[++i], "--cert") != 0)
         return -1;
-      }
-      free(config->tls_cert);
-      config->tls_cert = dup;
     } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --key\n");
+      if (set_string_option(&config->tls_key, argv[++i], "--key") != 0)
         return -1;
-      }
-      free(config->tls_key);
-      config->tls_key = dup;
     } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --ca\n");
+      if (set_string_option(&config->tls_ca, argv[++i], "--ca") != 0)
         return -1;
-      }
-      free(config->tls_ca);
-      config->tls_ca = dup;
     } else if (strcmp(argv[i], "--timeout") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --timeout must be a positive integer\n");
+      if (set_positive_int_option(&config->timeout, argv[++i], "--timeout") != 0)
         return -1;
-      }
-      config->timeout = val;
     } else if (strcmp(argv[i], "--contimeout") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --contimeout must be a positive integer\n");
+      if (set_positive_int_option(&config->contimeout, argv[++i], "--contimeout") != 0)
         return -1;
-      }
-      config->contimeout = val;
     } else if (strcmp(argv[i], "-q") == 0 || strcmp(argv[i], "--quiet") == 0 ||
                strcmp(argv[i], "--silent") == 0) {
       config->quiet = true;
     } else if (strcmp(argv[i], "--backup") == 0) {
       config->backup = true;
     } else if (strcmp(argv[i], "--backup-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --backup-dir\n");
+      if (set_string_option(&config->backup_dir, argv[++i], "--backup-dir") != 0)
         return -1;
-      }
-      free(config->backup_dir);
-      config->backup_dir = dup;
     } else if (strcmp(argv[i], "--stats") == 0) {
       config->stats = true;
     } else if (strcmp(argv[i], "--max-depth") == 0 && i + 1 < argc) {
-      if (!parse_nonneg_int(argv[++i], &config->max_depth)) {
-        fprintf(stderr, "Error: --max-depth must be a non-negative integer\n");
+      if (set_nonneg_int_option(&config->max_depth, argv[++i], "--max-depth") != 0)
         return -1;
-      }
     } else if (strcmp(argv[i], "--log-file") == 0 && i + 1 < argc) {
       FILE* lf = fopen(argv[++i], "a");
       if (!lf) {
@@ -263,12 +268,8 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       config->log_file = lf;
       log_set_file(lf);
     } else if (strcmp(argv[i], "--queue-size") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --queue-size must be a positive integer\n");
+      if (set_positive_int_option(&config->queue_size, argv[++i], "--queue-size") != 0)
         return -1;
-      }
-      config->queue_size = val;
     } else if (strcmp(argv[i], "--exclude-from") == 0 && i + 1 < argc) {
       if (read_patterns_from_file(argv[++i], &config->exclude_patterns, &config->exclude_count) !=
           0)
@@ -280,13 +281,9 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "--partial") == 0) {
       config->partial = true;
     } else if (strcmp(argv[i], "--fastsync-server-path") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --fastsync-server-path\n");
+      if (set_string_option(&config->fastsync_server_path, argv[++i], "--fastsync-server-path") !=
+          0)
         return -1;
-      }
-      free(config->fastsync_server_path);
-      config->fastsync_server_path = dup;
     } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
       set_log_level(LOG_LEVEL_DEBUG);
     } else if (strcmp(argv[i], "-l") == 0 || strcmp(argv[i], "--links") == 0) {
@@ -310,15 +307,14 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "-i") == 0 || strcmp(argv[i], "--itemize-changes") == 0) {
       config->itemize_changes = true;
     } else if (strcmp(argv[i], "--out-format") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->out_format, argv[++i], "--out-format") != 0)
         return -1;
-      free(config->out_format);
-      config->out_format = dup;
     } else if (strcmp(argv[i], "--info") == 0 && i + 1 < argc) {
-      config->info_level = atoi(argv[++i]);
+      if (set_nonneg_int_option(&config->info_level, argv[++i], "--info") != 0)
+        return -1;
     } else if (strcmp(argv[i], "--debug") == 0 && i + 1 < argc) {
-      config->debug_level = atoi(argv[++i]);
+      if (set_nonneg_int_option(&config->debug_level, argv[++i], "--debug") != 0)
+        return -1;
     } else if (strcmp(argv[i], "--list-only") == 0) {
       config->list_only = true;
     } else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--human-readable") == 0) {
@@ -336,12 +332,8 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "--delete-after") == 0) {
       config->delete_after = true;
     } else if (strcmp(argv[i], "--max-delete") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_nonneg_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --max-delete must be a non-negative integer\n");
+      if (set_nonneg_int_option(&config->max_delete, argv[++i], "--max-delete") != 0)
         return -1;
-      }
-      config->max_delete = val;
     } else if (strcmp(argv[i], "--filter") == 0 && i + 1 < argc) {
       if (!config->filters)
         config->filters = array_list_create(free);
@@ -350,11 +342,8 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
         return -1;
       array_list_add(config->filters, dup);
     } else if (strcmp(argv[i], "--files-from") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->files_from, argv[++i], "--files-from") != 0)
         return -1;
-      free(config->files_from);
-      config->files_from = dup;
     } else if (strcmp(argv[i], "--cvs-exclude") == 0) {
       config->cvs_exclude = true;
     } else if (strcmp(argv[i], "--prune-empty-dirs") == 0) {
@@ -363,82 +352,44 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
       config->relative = true;
     } else if (strcmp(argv[i], "-e") == 0 || strcmp(argv[i], "--rsh") == 0) {
       if (i + 1 < argc) {
-        char* dup = str_dup(argv[++i]);
-        if (!dup)
+        if (set_string_option(&config->rsh_command, argv[++i], "-e/--rsh") != 0)
           return -1;
-        free(config->rsh_command);
-        config->rsh_command = dup;
       } else {
         fprintf(stderr, "Error: -e/--rsh requires a command argument\n");
         return -1;
       }
     } else if (strcmp(argv[i], "--rsync-path") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->rsync_path, argv[++i], "--rsync-path") != 0)
         return -1;
-      free(config->rsync_path);
-      config->rsync_path = dup;
     } else if (strcmp(argv[i], "--temp-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->temp_dir, argv[++i], "--temp-dir") != 0)
         return -1;
-      free(config->temp_dir);
-      config->temp_dir = dup;
     } else if (strcmp(argv[i], "--compare-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->compare_dest, argv[++i], "--compare-dest") != 0)
         return -1;
-      free(config->compare_dest);
-      config->compare_dest = dup;
     } else if (strcmp(argv[i], "--copy-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->copy_dest, argv[++i], "--copy-dest") != 0)
         return -1;
-      free(config->copy_dest);
-      config->copy_dest = dup;
     } else if (strcmp(argv[i], "--link-dest") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->link_dest, argv[++i], "--link-dest") != 0)
         return -1;
-      free(config->link_dest);
-      config->link_dest = dup;
     } else if (strcmp(argv[i], "--partial-dir") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --partial-dir\n");
+      if (set_string_option(&config->partial_dir, argv[++i], "--partial-dir") != 0)
         return -1;
-      }
-      free(config->partial_dir);
-      config->partial_dir = dup;
     } else if (strcmp(argv[i], "--suffix") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup) {
-        fprintf(stderr, "Error: memory allocation failed for --suffix\n");
+      if (set_string_option(&config->suffix, argv[++i], "--suffix") != 0)
         return -1;
-      }
-      free(config->suffix);
-      config->suffix = dup;
     } else if (strcmp(argv[i], "--delete-before") == 0) {
       config->delete_before = true;
     } else if (strcmp(argv[i], "-T") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: -T must be a positive integer\n");
+      if (set_positive_int_option(&config->timeout, argv[++i], "-T") != 0)
         return -1;
-      }
-      config->timeout = val;
     } else if (strcmp(argv[i], "--address") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->address, argv[++i], "--address") != 0)
         return -1;
-      free(config->address);
-      config->address = dup;
     } else if (strcmp(argv[i], "--bind-address") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->bind_address, argv[++i], "--bind-address") != 0)
         return -1;
-      free(config->bind_address);
-      config->bind_address = dup;
     } else if (strcmp(argv[i], "--ipv6") == 0) {
       config->ipv6 = true;
     } else if (strcmp(argv[i], "--ipv4") == 0) {
@@ -446,28 +397,18 @@ static int parse_args(Config* config, int argc, char* argv[], int* positional_ar
     } else if (strcmp(argv[i], "--daemon") == 0) {
       config->daemon = true;
     } else if (strcmp(argv[i], "--config") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->daemon_config, argv[++i], "--config") != 0)
         return -1;
-      free(config->daemon_config);
-      config->daemon_config = dup;
     } else if (strcmp(argv[i], "--server") == 0) {
       config->server_mode = true;
     } else if (strcmp(argv[i], "--checksum") == 0) {
       config->checksum = true;
     } else if (strcmp(argv[i], "--compress-choice") == 0 && i + 1 < argc) {
-      char* dup = str_dup(argv[++i]);
-      if (!dup)
+      if (set_string_option(&config->compress_choice, argv[++i], "--compress-choice") != 0)
         return -1;
-      free(config->compress_choice);
-      config->compress_choice = dup;
     } else if (strcmp(argv[i], "--compress-level") == 0 && i + 1 < argc) {
-      int val;
-      if (!parse_positive_int(argv[++i], &val)) {
-        fprintf(stderr, "Error: --compress-level must be a positive integer\n");
+      if (set_positive_int_option(&config->compression_level, argv[++i], "--compress-level") != 0)
         return -1;
-      }
-      config->compression_level = val;
     } else if (argv[i][0] == '-') {
       fprintf(stderr, "Unknown option: %s\n", argv[i]);
       print_usage();

src/client/client_send.c

@@ -166,7 +166,7 @@ static int send_single_file(Client* client, File* file, Config* config, bool use
   if (!use_incremental) {
     if (use_sendfile) {
       return send_file_direct_sendfile(file, client->file_descriptor, config->use_metadata) ? 0
-                                                                                             : -1;
+                                                                                            : -1;
     }
     return send_file_direct(file, client->file_descriptor, config->use_metadata, compression_level)
                ? 0
@@ -284,8 +284,8 @@ static int send_chunks_multithreaded(void* pipeline_context) {
   } else if (context->config->use_tls) {
     client = client_create();
     if (!client || !client_connect_tls(client, context->config->server_host,
-                                        context->config->server_port, context->config->tls_cert,
-                                        context->config->tls_key, context->config->tls_ca)) {
+                                       context->config->server_port, context->config->tls_cert,
+                                       context->config->tls_key, context->config->tls_ca)) {
       if (client)
         client_delete(client);
       fprintf(stderr, "Error: could not connect to server via TLS\n");
@@ -374,7 +374,8 @@ static int scan_directory_multithreaded(void* pipeline_context) {
       context->config->exclude_patterns, context->config->exclude_count,
       context->config->include_patterns, context->config->include_count, context->config->max_size,
       context->config->min_size, context->config->max_depth, 4, context->config->follow_symlinks,
-      context->config->copy_links, context->config->safe_links, context->config->copy_unsafe_links, context->config->checksum);
+      context->config->copy_links, context->config->safe_links, context->config->copy_unsafe_links,
+      context->config->checksum);
 
   Chunk* current_chunk;
   while ((current_chunk = parallel_scanner_next(scanner)) != NULL) {
@@ -485,7 +486,7 @@ int send_files(Config* config) {
   } else if (config->use_tls) {
     client = client_create();
     if (!client || !client_connect_tls(client, config->server_host, config->server_port,
-                                        config->tls_cert, config->tls_key, config->tls_ca)) {
+                                       config->tls_cert, config->tls_key, config->tls_ca)) {
       if (client)
         client_delete(client);
       fprintf(stderr, "Error: could not connect to server via TLS\n");
@@ -575,8 +576,8 @@ int send_files(Config* config) {
   }
   if (config->stats) {
     double rate = elapsed_total > 0 ? total_bytes / (1048576.0 * elapsed_total) : 0;
-    fprintf(stderr, "Stats: %d files, %.1f MB, %.1f MB/s\n", total_files,
-            total_bytes / 1048576.0, rate);
+    fprintf(stderr, "Stats: %d files, %.1f MB, %.1f MB/s\n", total_files, total_bytes / 1048576.0,
+            rate);
   }
   directory_scanner_destroy(scanner);
   client_disconnect(client);

src/client/scanner.c

@@ -309,12 +309,12 @@ static int parallel_worker_thread(void* arg) {
 }
 
 ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata,
-                                          unsigned long long chunk_size, char** exclude_patterns,
-                                          int exclude_count, char** include_patterns,
-                                          int include_count, unsigned long long max_size,
-                                          unsigned long long min_size, int max_depth,
-                                          int num_threads, bool follow_symlinks, bool copy_links,
-                                          bool safe_links, bool copy_unsafe_links, bool checksum) {
+                                         unsigned long long chunk_size, char** exclude_patterns,
+                                         int exclude_count, char** include_patterns,
+                                         int include_count, unsigned long long max_size,
+                                         unsigned long long min_size, int max_depth,
+                                         int num_threads, bool follow_symlinks, bool copy_links,
+                                         bool safe_links, bool copy_unsafe_links, bool checksum) {
   ParallelScanner* ps = calloc(1, sizeof(ParallelScanner));
   if (!ps)
     return NULL;
@@ -347,11 +347,62 @@ ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata
     char* cur_path = path_cat(root_directory, entry->d_name);
     if (!cur_path)
       continue;
-    struct stat st;
-    if (stat(cur_path, &st) != 0) {
+    struct stat lstats;
+    if (lstat(cur_path, &lstats) != 0) {
       free(cur_path);
       continue;
     }
+    bool is_symlink = S_ISLNK(lstats.st_mode);
+
+    // Skip symlinks unless the user explicitly enabled following/copying them.
+    if (is_symlink && !follow_symlinks && !copy_links && !safe_links && !copy_unsafe_links) {
+      free(cur_path);
+      continue;
+    }
+
+    // --safe-links: reject symlinks pointing outside the source tree.
+    if (is_symlink && safe_links) {
+      char link_target[4096];
+      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
+      if (len < 0) {
+        free(cur_path);
+        continue;
+      }
+      link_target[len] = 0;
+      if (link_target[0] == '/') {
+        free(cur_path);
+        continue;
+      }
+    }
+
+    // --copy-unsafe-links (without --copy-links): only copy absolute symlinks.
+    if (is_symlink && copy_unsafe_links && !copy_links) {
+      char link_target[4096];
+      ssize_t len = readlink(cur_path, link_target, sizeof(link_target) - 1);
+      if (len < 0) {
+        free(cur_path);
+        continue;
+      }
+      link_target[len] = 0;
+      bool unsafe = (link_target[0] == '/');
+      if (!unsafe) {
+        free(cur_path);
+        continue;
+      }
+    }
+
+    // Determine whether to use lstat or stat results for the entry.
+    struct stat st;
+    bool use_lstat_res = is_symlink && follow_symlinks && !copy_links;
+    if (use_lstat_res) {
+      st = lstats;
+    } else {
+      if (stat(cur_path, &st) != 0) {
+        free(cur_path);
+        continue;
+      }
+    }
+
     if (S_ISDIR(st.st_mode)) {
       array_list_add(subdirs, cur_path);
     } else {

src/client/scanner.h

@@ -51,12 +51,12 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner);
 void directory_scanner_destroy(DirectoryScanner* scanner);
 
 ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata,
-                                          unsigned long long chunk_size, char** exclude_patterns,
-                                          int exclude_count, char** include_patterns,
-                                          int include_count, unsigned long long max_size,
-                                          unsigned long long min_size, int max_depth,
-                                          int num_threads, bool follow_symlinks, bool copy_links,
-                                          bool safe_links, bool copy_unsafe_links, bool checksum);
+                                         unsigned long long chunk_size, char** exclude_patterns,
+                                         int exclude_count, char** include_patterns,
+                                         int include_count, unsigned long long max_size,
+                                         unsigned long long min_size, int max_depth,
+                                         int num_threads, bool follow_symlinks, bool copy_links,
+                                         bool safe_links, bool copy_unsafe_links, bool checksum);
 Chunk* parallel_scanner_next(ParallelScanner* scanner);
 void parallel_scanner_destroy(ParallelScanner* scanner);
 

src/shared/chunk.c

@@ -12,6 +12,9 @@
 #include "metadata.h"
 #include "protocol.h"
 
+/* Maximum individual file data size within a chunk (64 MB) */
+#define MAX_FILE_DATA_SIZE (64ULL * 1024 * 1024)
+
 Chunk* chunk_create(File** items, int element_count) {
   Chunk* chunk = (Chunk*)malloc(sizeof(Chunk));
   if (chunk == NULL) {
@@ -157,6 +160,14 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
       return NULL;
     }
 
+    // Reject individual file data larger than the maximum allowed size.
+    if (file_data_size > MAX_FILE_DATA_SIZE) {
+      log_message(LOG_LEVEL_ERROR, "File data size %zu exceeds maximum %llu", file_data_size,
+                  (unsigned long long)MAX_FILE_DATA_SIZE);
+      array_list_delete(files);
+      return NULL;
+    }
+
     void* file_data = malloc(file_data_size);
     if (file_data == NULL) {
       perror("Could not allocate memory for file data");
@@ -210,6 +221,15 @@ Chunk* receive_chunk_data(int fd, const Config* config) {
       return NULL;
     }
   }
+
+  // Reject chunks larger than the maximum allowed size to prevent OOM.
+  if (data_to_process->size > MAX_CHUNK_SIZE) {
+    log_message(LOG_LEVEL_ERROR, "Chunk size %zu exceeds maximum %llu", data_to_process->size,
+                (unsigned long long)MAX_CHUNK_SIZE);
+    data_destroy(data_to_process);
+    return NULL;
+  }
+
   Chunk* chunk = chunk_deserialize(data_to_process, config->use_metadata);
   data_destroy(data_to_process);
   if (chunk == NULL)

src/shared/file.c

@@ -35,7 +35,8 @@ File* file_create(const char* path) {
     return NULL;
   }
 
-  strcpy(file->path, path);
+  memcpy(file->path, path, path_len);
+  file->path[path_len] = '\0';
   file->data = data_create_reserve(0);
   if (file->data == NULL) {
     free(file->path);
@@ -142,7 +143,8 @@ bool file_save_to_disk(const char* root_directory, File* file, const Config* con
   }
 
   char* resolved_root = NULL;
-  const char* actual_root = (partial_dir && config && config->partial) ? partial_dir : root_directory;
+  const char* actual_root =
+      (partial_dir && config && config->partial) ? partial_dir : root_directory;
   resolved_root = realpath(actual_root, NULL);
   if (resolved_root == NULL) {
     if (mkdir_r(actual_root)) {
@@ -187,7 +189,7 @@ bool file_save_to_disk(const char* root_directory, File* file, const Config* con
       if (backup_path) {
         char* backup_dir_path = str_dup(backup_path);
         if (backup_dir_path) {
-          char* bdir = dirname(backup_dir_path);
+          const char* bdir = dirname(backup_dir_path);
           mkdir_r(bdir);
           free(backup_dir_path);
         }
@@ -222,8 +224,7 @@ bool file_save_to_disk(const char* root_directory, File* file, const Config* con
   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);
+    log_message(LOG_LEVEL_ERROR, "Path escape detected: %s is outside %s", disk_path, actual_root);
     free(resolved_dir);
     free(resolved_root);
     free(disk_path);
@@ -517,8 +518,8 @@ File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
   return file;
 }
 
-bool to_disk(const char* path, const void* data, unsigned long long data_size,
-             bool inplace, bool sparse) {
+bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
+             bool sparse) {
   char* tmp_path = NULL;
   char* directory = NULL;
 

src/shared/file.h

@@ -34,8 +34,8 @@ bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int
 size_t file_content_to_buffer(File* file);
 FileMetadata* file_metadata_create(const struct stat* stats);
 void file_metadata_destroy(void* metadata);
-bool to_disk(const char* path, const void* data, unsigned long long data_size,
-             bool inplace, bool sparse);
+bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
+             bool sparse);
 bool file_save_to_disk(const char* root_directory, File* file, const Config* config);
 File* receive_incremental_check(int fd, const Config* config, bool* skipped);
 int receive_manifest(int fd, const Config* config, int* next_status);

src/shared/multiprocessing.c

@@ -14,7 +14,7 @@
 #include <threads.h>
 
 PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* queue_scanner,
-                                                       Queue* queue_loader) {
+                                                      Queue* queue_loader) {
   PipelineContextSender* context = malloc(sizeof(PipelineContextSender));
   if (context == NULL)
     return NULL;
@@ -58,7 +58,7 @@ void pipeline_context_sender_destroy(PipelineContextSender* context) {
 }
 
 PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue* queue,
-                                                           int file_descriptor, SSL* ssl) {
+                                                          int file_descriptor, SSL* ssl) {
   PipelineContextReceiver* context = malloc(sizeof(PipelineContextReceiver));
   if (context == NULL)
     return NULL;

src/shared/multiprocessing.h

@@ -40,10 +40,10 @@ typedef struct PipelineContextReceiver {
 } PipelineContextReceiver;
 
 PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* queue_scanner,
-                                                       Queue* queue_loader);
+                                                      Queue* queue_loader);
 void pipeline_context_sender_destroy(PipelineContextSender* context);
 PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue* queue_receiver,
-                                                           int file_descriptor, SSL* ssl);
+                                                          int file_descriptor, SSL* ssl);
 void pipeline_context_receiver_destroy(PipelineContextReceiver* context);
 int receive_thread(void* pipeline_context);
 int write_thread(void* pipeline_context);

src/shared/protocol.h

@@ -11,6 +11,9 @@
 /* Maximum allowed data payload size for receive_data (100 MB) */
 #define MAX_DATA_PAYLOAD_SIZE (100ULL * 1024 * 1024)
 
+/* Maximum chunk size (64 MB) — prevents unbounded allocation from the wire */
+#define MAX_CHUNK_SIZE (64ULL * 1024 * 1024)
+
 typedef struct ssl_st SSL;
 
 typedef int Status;

src/shared/utils.c

@@ -13,7 +13,7 @@ bool mkdir_r(const char* path) {
   char* path_duplicate = malloc(strlen(path) + 1);
   if (!path_duplicate)
     return false;
-  strcpy(path_duplicate, path);
+  memcpy(path_duplicate, path, strlen(path) + 1);
   char* path_current = (char*)malloc((strlen(path) + 2) * sizeof(char));
   if (!path_current) {
     free(path_duplicate);
@@ -21,7 +21,8 @@ bool mkdir_r(const char* path) {
   }
   char* path_current_position = path_current;
   if (path[0] == '/') {
-    strcpy(path_current, "/");
+    path_current[0] = '/';
+    path_current[1] = '\0';
     path_current_position += 1;
   } else {
     path_current[0] = '\0';
@@ -31,10 +32,12 @@ bool mkdir_r(const char* path) {
   const char* part = strtok_r(path_duplicate, delimiter, &saveptr);
   bool ok = true;
   while (part != NULL) {
-    strcpy(path_current_position, part);
-    path_current_position += strlen(part) * sizeof(char);
-    strcpy(path_current_position, "/");
-    path_current_position += sizeof(char);
+    size_t part_len = strlen(part);
+    memcpy(path_current_position, part, part_len);
+    path_current_position += part_len;
+    path_current_position[0] = '/';
+    path_current_position[1] = '\0';
+    path_current_position++;
     struct stat st;
     if (stat(path_current, &st) != 0) {
       if (mkdir(path_current, 0755) != 0) {
@@ -53,8 +56,11 @@ bool mkdir_r(const char* path) {
 char* str_dup(const char* string) {
   if (string == NULL)
     return NULL;
-  char* new_string = (char*)malloc(strlen(string) + 1);
-  strcpy(new_string, string);
+  size_t str_len = strlen(string);
+  char* new_string = (char*)malloc(str_len + 1);
+  if (new_string == NULL)
+    return NULL;
+  memcpy(new_string, string, str_len + 1);
   return new_string;
 }