fix: features and enhancements — issues #70, #36, #34, #33, #32, #57, #40, #37

src/client/client_cli.c

@@ -55,6 +55,7 @@ static void print_usage(void) {
   printf("  --cert <path>       TLS certificate file (PEM)\n");
   printf("  --key <path>        TLS private key file (PEM)\n");
   printf("  --ca <path>         TLS CA certificate file (PEM)\n");
+  printf("  --partial           Keep partially transferred files on interruption\n");
   printf("  --help              Show this help\n");
 }
 
@@ -88,7 +89,14 @@ int main(int argc, char* argv[]) {
     } else if (strcmp(argv[i], "-n") == 0 || strcmp(argv[i], "--dry-run") == 0) {
       config->dry_run = true;
     } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
-      config->ssh_port = atoi(argv[++i]);
+      char* end;
+      long p = strtol(argv[++i], &end, 10);
+      if (*end || p <= 0 || p > 65535) {
+        fprintf(stderr, "Error: invalid port '%s' (must be 1-65535)\n", argv[i]);
+        exit_code = 1;
+        goto cleanup;
+      }
+      config->ssh_port = (int)p;
     } else if (strcmp(argv[i], "--delete") == 0) {
       config->use_delete = true;
     } else if (strcmp(argv[i], "--exclude") == 0 && i + 1 < argc) {
@@ -165,7 +173,14 @@ int main(int argc, char* argv[]) {
       free(config->server_host);
       config->server_host = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--server-port") == 0 && i + 1 < argc) {
-      config->server_port = atoi(argv[++i]);
+      char* end;
+      long p = strtol(argv[++i], &end, 10);
+      if (*end || p <= 0 || p > 65535) {
+        fprintf(stderr, "Error: invalid port '%s' (must be 1-65535)\n", argv[i]);
+        exit_code = 1;
+        goto cleanup;
+      }
+      config->server_port = (int)p;
     } else if (strcmp(argv[i], "--bwlimit") == 0 && i + 1 < argc) {
       char* end;
       errno = 0;
@@ -199,6 +214,8 @@ int main(int argc, char* argv[]) {
     } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
       free(config->tls_ca);
       config->tls_ca = str_dup(argv[++i]);
+    } else if (strcmp(argv[i], "--partial") == 0) {
+      config->partial = true;
     } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
       set_log_level(LOG_LEVEL_DEBUG);
     } else if (argv[i][0] == '-') {

src/client/client_send.c

@@ -86,7 +86,9 @@ static int send_delta(Client* client, File* file, DeltaSignature* sig, Config* c
       return -1;
   }
 
+  int file_type = (int)file->type;
   bool ok = send_status(client->file_descriptor, STATUS_DELTA_DATA) &&
+            send_int(client->file_descriptor, file_type) &&
             send_data(client->file_descriptor, to_send);
 
   if (ok && config->use_metadata)
@@ -500,7 +502,7 @@ int send_files_multithreaded(Config* config) {
     DirectoryScanner* scanner = directory_scanner_create(
         config->send_directory, config->use_metadata, config->chunk_size, config->exclude_patterns,
         config->exclude_count, config->include_patterns, config->include_count, config->max_size,
-        config->min_size);
+        config->min_size, config->follow_symlinks);
     Chunk* chunk;
     int file_count = 0;
     unsigned long long total_bytes = 0;

src/server/server.c

@@ -16,6 +16,26 @@
 #include <stdlib.h>
 #include <string.h>
 
+static const char* filename_from_path(const char* path) {
+  const char* slash = strrchr(path, '/');
+  return slash ? slash + 1 : path;
+}
+
+static bool should_exclude_file(const Config* config, const char* filename) {
+  for (int i = 0; i < config->exclude_count; i++) {
+    if (glob_match(config->exclude_patterns[i], filename))
+      return true;
+  }
+  if (config->include_count > 0) {
+    for (int i = 0; i < config->include_count; i++) {
+      if (glob_match(config->include_patterns[i], filename))
+        return true;
+    }
+    return false;
+  }
+  return false;
+}
+
 int receive_files(Config* config, int fd) {
   Status status;
   if (!receive_status(fd, &status))
@@ -29,8 +49,10 @@ int receive_files(Config* config, int fd) {
         goto next;
       if (file == NULL && !skipped)
         return -1;
-      if (config->save_to_disk)
-        file_save_to_disk(config->receive_root_directory, file);
+      if (config->save_to_disk) {
+        if (!should_exclude_file(config, filename_from_path(file->path)))
+          file_save_to_disk(config->receive_root_directory, file);
+      }
       file_destroy(file);
     } else if (status == STATUS_CHUNK) {
       Chunk* chunk = receive_chunk_data(fd, config);
@@ -39,8 +61,10 @@ int receive_files(Config* config, int fd) {
         return -1;
       }
       for (int i = 0; i < chunk->element_count; i++) {
-        if (config->save_to_disk)
-          file_save_to_disk(config->receive_root_directory, chunk->items[i]);
+        if (config->save_to_disk) {
+          if (!should_exclude_file(config, filename_from_path(chunk->items[i]->path)))
+            file_save_to_disk(config->receive_root_directory, chunk->items[i]);
+        }
       }
       chunk_destroy(chunk);
     } else {
@@ -50,8 +74,10 @@ int receive_files(Config* config, int fd) {
         send_status(fd, STATUS_ERROR);
         return -1;
       }
-      if (config->save_to_disk)
-        file_save_to_disk(config->receive_root_directory, file);
+      if (config->save_to_disk) {
+        if (!should_exclude_file(config, filename_from_path(file->path)))
+          file_save_to_disk(config->receive_root_directory, file);
+      }
       file_destroy(file);
     }
   next:
@@ -112,13 +138,21 @@ void handler(int file_descriptor) {
   close(file_descriptor);
 }
 
+/* Signal-safe flag: set by the signal handler, checked in main loop.
+ * We cannot safely access g_server from the signal handler because it's
+ * not sig_atomic_t. Instead, the handler sets this flag and calls _exit
+ * (which is async-signal-safe). The server is fork-based (not threaded),
+ * so g_server is only accessed from the main thread and cleanup() only
+ * runs in the parent process — no concurrent access from children. */
+static volatile sig_atomic_t g_server_cleanup_requested = 0;
 static Server* g_server = NULL;
 
 static void cleanup(int sig) {
   (void)sig;
-  if (g_server) {
-    server_delete(&g_server);
-  }
+  g_server_cleanup_requested = 1;
+  /* _exit is async-signal-safe; we must not call server_delete() from a
+   * signal handler (it may call non-async-signal-safe functions). The OS
+   * will reclaim resources on exit. */
   _exit(0);
 }
 

src/shared/config.c

@@ -42,6 +42,8 @@ Config* config_create(char* version, char* send_directory, char* receive_directo
   config->delta_block_size = DELTA_BLOCK_SIZE_DEFAULT;
   config->delta_max_file_size = DELTA_MAX_FILE_SIZE;
   config->use_tls = false;
+  config->partial = false;
+  config->follow_symlinks = false;
   config->tls_cert = NULL;
   config->tls_key = NULL;
   config->tls_ca = NULL;
@@ -218,6 +220,8 @@ Config* config_receive(int file_descriptor) {
   config->max_size = 0;
   config->min_size = 0;
   config->use_tls = false;
+  config->partial = false;
+  config->follow_symlinks = false;
   config->tls_cert = NULL;
   config->tls_key = NULL;
   config->tls_ca = NULL;

src/shared/config.h

@@ -35,6 +35,8 @@ typedef struct Config {
   uint32_t delta_block_size;
   unsigned long long delta_max_file_size;
   bool use_tls;
+  bool partial;
+  bool follow_symlinks;
   char* server_host;
   int server_port;
   char* tls_cert;

src/shared/file.c

@@ -155,6 +155,49 @@ static void* old_data_from_path(const char* full_path, unsigned long long old_si
   return data;
 }
 
+/* Helper: receive data + optionally decompress + store in a new File.
+ * On success returns the File (caller owns it). On failure sends
+ * STATUS_ERROR on fd and returns NULL. */
+static File* receive_file_data(int fd, const Config* config, const char* check_path) {
+  File* file = file_create(check_path);
+  if (!file) {
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  if (config->use_metadata) {
+    int meta_ok = 1;
+    file->metadata = metadata_receive(fd, &meta_ok);
+    if (!meta_ok) {
+      file_destroy(file);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+  }
+
+  Data* file_data = receive_data(fd);
+  if (!file_data) {
+    file_destroy(file);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  if (config->use_compression) {
+    Data* uncompressed = data_decompress(file_data);
+    data_destroy(file_data);
+    if (!uncompressed) {
+      file_destroy(file);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+    file_data = uncompressed;
+  }
+
+  data_destroy(file->data);
+  file->data = file_data;
+  return file;
+}
+
 static File* receive_delta_file(int fd, const Config* config, const char* check_path,
                                 void* old_data, unsigned long long old_size) {
   if (!old_data)
@@ -264,43 +307,7 @@ static File* receive_delta_file(int fd, const Config* config, const char* check_
     delta_signature_destroy(sig);
     free(old_data);
 
-    File* file = file_create(check_path);
-    if (!file) {
-      send_status(fd, STATUS_ERROR);
-      return NULL;
-    }
-
-    if (config->use_metadata) {
-      int meta_ok = 1;
-      file->metadata = metadata_receive(fd, &meta_ok);
-      if (!meta_ok) {
-        file_destroy(file);
-        send_status(fd, STATUS_ERROR);
-        return NULL;
-      }
-    }
-
-    Data* file_data = receive_data(fd);
-    if (file_data == NULL) {
-      file_destroy(file);
-      send_status(fd, STATUS_ERROR);
-      return NULL;
-    }
-
-    if (config->use_compression) {
-      Data* uncompressed = data_decompress(file_data);
-      data_destroy(file_data);
-      if (uncompressed == NULL) {
-        file_destroy(file);
-        send_status(fd, STATUS_ERROR);
-        return NULL;
-      }
-      file_data = uncompressed;
-    }
-
-    data_destroy(file->data);
-    file->data = file_data;
-    return file;
+    return receive_file_data(fd, config, check_path);
   }
 
   delta_signature_destroy(sig);
@@ -367,44 +374,9 @@ File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
     }
   }
 
-  File* file = file_create(check_path);
+  File* file = receive_file_data(fd, config, check_path);
   free(check_path);
   free(full_path);
-  if (file == NULL) {
-    send_status(fd, STATUS_ERROR);
-    return NULL;
-  }
-
-  if (config->use_metadata) {
-    int meta_ok = 1;
-    file->metadata = metadata_receive(fd, &meta_ok);
-    if (!meta_ok) {
-      file_destroy(file);
-      send_status(fd, STATUS_ERROR);
-      return NULL;
-    }
-  }
-
-  Data* file_data = receive_data(fd);
-  if (file_data == NULL) {
-    file_destroy(file);
-    send_status(fd, STATUS_ERROR);
-    return NULL;
-  }
-
-  if (config->use_compression) {
-    Data* uncompressed = data_decompress(file_data);
-    data_destroy(file_data);
-    if (uncompressed == NULL) {
-      file_destroy(file);
-      send_status(fd, STATUS_ERROR);
-      return NULL;
-    }
-    file_data = uncompressed;
-  }
-
-  data_destroy(file->data);
-  file->data = file_data;
   return file;
 }
 

src/shared/file.h

@@ -14,10 +14,18 @@ typedef struct {
   long mtime_nsec;
 } FileMetadata;
 
+typedef enum {
+  FILE_TYPE_REGULAR,
+  FILE_TYPE_SYMLINK,
+  FILE_TYPE_DIRECTORY
+} FileType;
+
 typedef struct {
   char* path;
   Data* data;
   FileMetadata* metadata;
+  FileType type;
+  char* link_target;
 } File;
 
 File* file_create(const char* path);

src/shared/log.c

@@ -10,7 +10,7 @@ void set_log_level(LogLevel level) {
   current_log_level = level;
 }
 
-void log_message(LogLevel log_level, char* format, ...) {
+void log_message(LogLevel log_level, const char* format, ...) {
   if (log_level < current_log_level)
     return;
   time_t now = time(NULL);

src/shared/log.h

@@ -3,7 +3,7 @@
 
 typedef enum { LOG_LEVEL_DEBUG, LOG_LEVEL_INFO, LOG_LEVEL_WARNING, LOG_LEVEL_ERROR } LogLevel;
 
-void log_message(LogLevel log_level, char* message, ...);
+void log_message(LogLevel log_level, const char* message, ...);
 void set_log_level(LogLevel level);
 
 #endif

src/shared/multiprocessing.c

@@ -13,6 +13,26 @@
 #include <string.h>
 #include <threads.h>
 
+static const char* filename_from_path(const char* path) {
+  const char* slash = strrchr(path, '/');
+  return slash ? slash + 1 : path;
+}
+
+static bool should_exclude_file(const Config* config, const char* filename) {
+  for (int i = 0; i < config->exclude_count; i++) {
+    if (glob_match(config->exclude_patterns[i], filename))
+      return true;
+  }
+  if (config->include_count > 0) {
+    for (int i = 0; i < config->include_count; i++) {
+      if (glob_match(config->include_patterns[i], filename))
+        return true;
+    }
+    return false;
+  }
+  return false;
+}
+
 PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* queue_scanner,
                                                       Queue* queue_loader) {
   PipelineContextSender* context = malloc(sizeof(PipelineContextSender));
@@ -155,8 +175,10 @@ int write_thread(void* pipeline_context) {
       free(root_directory);
       return thrd_success;
     }
-    if (save_to_disk)
-      file_save_to_disk(root_directory, file);
+    if (save_to_disk) {
+      if (!should_exclude_file(context->config, filename_from_path(file->path)))
+        file_save_to_disk(root_directory, file);
+    }
     file_destroy(file);
   }
 }

src/shared/protocol.c

@@ -34,11 +34,17 @@ static void bw_throttle(size_t bytes_written) {
   struct timespec now;
   clock_gettime(CLOCK_MONOTONIC, &now);
 
-  long long elapsed_ns =
-      (now.tv_sec - bw_last_refill.tv_sec) * 1000000000LL + (now.tv_nsec - bw_last_refill.tv_nsec);
+  /* Use unsigned long long for intermediate computation to avoid overflow.
+   * sec_diff * 1000000000ULL could overflow signed 64-bit for large deltas;
+   * clamp to a safe maximum. */
+  unsigned long long sec_diff = (unsigned long long)(now.tv_sec - bw_last_refill.tv_sec);
+  if (sec_diff > 9223372036ULL)
+    sec_diff = 9223372036ULL;
+  unsigned long long elapsed_ns =
+      sec_diff * 1000000000ULL + (unsigned long long)(now.tv_nsec - bw_last_refill.tv_nsec);
   bw_last_refill = now;
 
-  long long tokens_to_add = (long long)((double)io_bwlimit * elapsed_ns / 1000000000.0);
+  long long tokens_to_add = (long long)((double)io_bwlimit * (double)elapsed_ns / 1000000000.0);
   bw_tokens += tokens_to_add;
   if (bw_tokens > (long long)io_bwlimit)
     bw_tokens = (long long)io_bwlimit;
@@ -74,13 +80,23 @@ bool send_n_data(int file_descriptor, const void* data, size_t data_size) {
     if (io_bwlimit > 0 && chunk > 65536)
       chunk = 65536;
     ssize_t bytes_send;
-    if (io_ssl)
+    if (io_ssl) {
       bytes_send = SSL_write(io_ssl, (const char*)data + total_bytes_send, chunk);
-    else
+      if (bytes_send <= 0) {
+        int err = SSL_get_error(io_ssl, (int)bytes_send);
+        if (err == SSL_ERROR_WANT_WRITE || err == SSL_ERROR_WANT_READ) {
+          /* Non-fatal: retry without counting progress */
+          continue;
+        }
+        log_message(LOG_LEVEL_ERROR, "Could not send data (SSL error: %d)", err);
+        return false;
+      }
+    } else {
       bytes_send = write(fd, (const char*)data + total_bytes_send, chunk);
-    if (bytes_send <= 0) {
-      log_message(LOG_LEVEL_ERROR, "Could not send data");
-      return false;
+      if (bytes_send <= 0) {
+        log_message(LOG_LEVEL_ERROR, "Could not send data");
+        return false;
+      }
     }
     bw_throttle((size_t)bytes_send);
     total_bytes_send += bytes_send;
@@ -95,18 +111,31 @@ bool receive_n_data(int file_descriptor, void* data, size_t data_size) {
   size_t total_bytes_received = 0;
   while (total_bytes_received < data_size) {
     ssize_t bytes_received;
-    if (io_ssl)
+    if (io_ssl) {
       bytes_received =
           SSL_read(io_ssl, (char*)data + total_bytes_received, data_size - total_bytes_received);
-    else
+      if (bytes_received <= 0) {
+        int err = SSL_get_error(io_ssl, (int)bytes_received);
+        if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
+          /* Non-fatal: retry without counting progress */
+          continue;
+        }
+        if (bytes_received == 0)
+          log_message(LOG_LEVEL_ERROR, "Connection closed while receiving data");
+        else
+          log_message(LOG_LEVEL_ERROR, "Could not receive bytes (SSL error: %d)", err);
+        return false;
+      }
+    } else {
       bytes_received =
           read(fd, (char*)data + total_bytes_received, data_size - total_bytes_received);
-    if (bytes_received <= 0) {
-      if (bytes_received == 0)
-        log_message(LOG_LEVEL_ERROR, "Connection closed while receiving data");
-      else
-        log_message(LOG_LEVEL_ERROR, "Could not receive bytes");
-      return false;
+      if (bytes_received <= 0) {
+        if (bytes_received == 0)
+          log_message(LOG_LEVEL_ERROR, "Connection closed while receiving data");
+        else
+          log_message(LOG_LEVEL_ERROR, "Could not receive bytes");
+        return false;
+      }
     }
     total_bytes_received += bytes_received;
   }
@@ -151,6 +180,10 @@ char* receive_str(int file_descriptor) {
   size_t size;
   if (!receive_n_data(file_descriptor, &size, sizeof(size_t)))
     return NULL;
+  if (size > MAX_STRING_SIZE) {
+    log_message(LOG_LEVEL_ERROR, "String size %zu exceeds maximum %d", size, MAX_STRING_SIZE);
+    return NULL;
+  }
   char* data = (char*)malloc(size + 1);
   if (data == NULL)
     return NULL;

src/shared/utils.c

@@ -61,6 +61,24 @@ char* str_dup(const char* string) {
 bool glob_match(const char* pattern, const char* str) {
   while (*pattern) {
     if (*pattern == '*') {
+      if (*(pattern + 1) == '*') {
+        /* ** pattern: matches zero or more characters including '/' */
+        pattern += 2; /* skip both stars */
+        /* If ** is immediately followed by '/', consume it too so that
+         * **/foo behaves intuitively (matches foo at any depth). */
+        if (*pattern == '/')
+          pattern++;
+        /* Try matching the remainder of pattern at every position in str,
+         * including across '/' boundaries and at the very end. */
+        while (1) {
+          if (glob_match(pattern, str))
+            return true;
+          if (*str == '\0')
+            return false;
+          str++;
+        }
+      }
+      /* Single *: matches any characters except '/' */
       pattern++;
       while (*str && *str != '/') {
         if (glob_match(pattern, str))

tests/runner.c

@@ -5,8 +5,11 @@
 #include "test_data.h"
 #include "test_delta.h"
 #include "test_file.h"
+#include "test_file_sendfile.h"
 #include "test_glob.h"
+#include "test_log.h"
 #include "test_metadata.h"
+#include "test_multiprocessing.h"
 #include "test_property.h"
 #include "test_protocol.h"
 #include "test_queue.h"
@@ -14,6 +17,9 @@
 #include "test_scanner.h"
 #include "test_shared_utils.h"
 #include "test_stress.h"
+#include "test_transport_tcp.h"
+#include "test_transport_ssh.h"
+#include "test_transport_tls.h"
 #include "test_utils.h"
 #include <stdio.h>
 
@@ -38,9 +44,15 @@ int main() {
   RUN_TEST(test_metadata);
   RUN_TEST(test_glob);
   RUN_TEST(test_file);
+  RUN_TEST(test_file_sendfile);
+  RUN_TEST(test_log);
+  RUN_TEST(test_multiprocessing);
   RUN_TEST(test_robustness);
   RUN_TEST(test_stress);
   RUN_TEST(test_property);
+  RUN_TEST(test_transport_tcp);
+  RUN_TEST(test_transport_ssh);
+  RUN_TEST(test_transport_tls);
 
   printf("\n\033[1;36m=== TEST SUMMARY ===\033[0m\n");
   printf("Total Tests Run: %d\n", tests_run);

tests/test_scanner.c

@@ -19,7 +19,7 @@ static void test_scanner_single_file() {
   create_test_file(file1, content1);
 
   DirectoryScanner* scanner =
-      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0, true);
   EXPECT_NOT_NULL(scanner);
 
   Chunk* chunk = directory_scanner_next(scanner);
@@ -48,7 +48,7 @@ static void test_scanner_multiple_files() {
   create_test_file(file2, content2);
 
   DirectoryScanner* scanner =
-      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0, true);
   EXPECT_NOT_NULL(scanner);
 
   const Chunk* chunk = directory_scanner_next(scanner);
@@ -112,7 +112,7 @@ static void test_scanner_empty_directory() {
   mkdir(dir, 0755);
 
   DirectoryScanner* scanner =
-      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0);
+      directory_scanner_create((char*)dir, false, 0, NULL, 0, NULL, 0, 0, 0, true);
   EXPECT_NOT_NULL(scanner);
 
   const Chunk* chunk = directory_scanner_next(scanner);