fix: const qualifier for dirent pointer (cppcheck)

src/client/client_cli.c

@@ -56,7 +56,6 @@ static void print_usage(void) {
   printf("  --key <path>        TLS private key file (PEM)\n");
   printf("  --ca <path>         TLS CA certificate file (PEM)\n");
   printf("  --help              Show this help\n");
-  printf("  -V, --version       Show version and exit\n");
 }
 
 int main(int argc, char* argv[]) {
@@ -81,9 +80,6 @@ int main(int argc, char* argv[]) {
     if (strcmp(argv[i], "--help") == 0) {
       print_usage();
       goto cleanup;
-    } else if (strcmp(argv[i], "-V") == 0 || strcmp(argv[i], "--version") == 0) {
-      printf("fastsync version %s\n", PROTOCOL_VERSION);
-      goto cleanup;
     } else if (strcmp(argv[i], "-a") == 0 || strcmp(argv[i], "--archive") == 0) {
       config->use_compression = true;
       config->use_multithreading = true;

src/client/scanner.c

@@ -24,9 +24,58 @@ DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metada
   scanner->current_path = NULL;
   scanner->use_metadata = use_metadata;
   scanner->chunk_size = chunk_size > 0 ? chunk_size : DESIRED_CHUNK_SIZE;
-  scanner->exclude_patterns = exclude_patterns;
+  /* Deep-copy exclude patterns */
+  if (exclude_count > 0 && exclude_patterns != NULL) {
+    scanner->exclude_patterns = malloc((size_t)exclude_count * sizeof(char*));
+    if (scanner->exclude_patterns == NULL) {
+      queue_destroy(scanner->directories);
+      free(scanner);
+      return NULL;
+    }
+    for (int i = 0; i < exclude_count; i++) {
+      scanner->exclude_patterns[i] = str_dup(exclude_patterns[i]);
+      if (scanner->exclude_patterns[i] == NULL) {
+        for (int j = 0; j < i; j++)
+          free(scanner->exclude_patterns[j]);
+        free(scanner->exclude_patterns);
+        queue_destroy(scanner->directories);
+        free(scanner);
+        return NULL;
+      }
+    }
+  } else {
+    scanner->exclude_patterns = NULL;
+  }
   scanner->exclude_count = exclude_count;
-  scanner->include_patterns = include_patterns;
+
+  /* Deep-copy include patterns */
+  if (include_count > 0 && include_patterns != NULL) {
+    scanner->include_patterns = malloc((size_t)include_count * sizeof(char*));
+    if (scanner->include_patterns == NULL) {
+      for (int i = 0; i < exclude_count; i++)
+        free(scanner->exclude_patterns[i]);
+      free(scanner->exclude_patterns);
+      queue_destroy(scanner->directories);
+      free(scanner);
+      return NULL;
+    }
+    for (int i = 0; i < include_count; i++) {
+      scanner->include_patterns[i] = str_dup(include_patterns[i]);
+      if (scanner->include_patterns[i] == NULL) {
+        for (int j = 0; j < i; j++)
+          free(scanner->include_patterns[j]);
+        free(scanner->include_patterns);
+        for (int j = 0; j < exclude_count; j++)
+          free(scanner->exclude_patterns[j]);
+        free(scanner->exclude_patterns);
+        queue_destroy(scanner->directories);
+        free(scanner);
+        return NULL;
+      }
+    }
+  } else {
+    scanner->include_patterns = NULL;
+  }
   scanner->include_count = include_count;
   scanner->max_size = max_size;
   scanner->min_size = min_size;
@@ -42,6 +91,12 @@ void directory_scanner_destroy(DirectoryScanner* scanner) {
     scanner->current_dir = NULL;
   }
   free(scanner->current_path);
+  for (int i = 0; i < scanner->exclude_count; i++)
+    free(scanner->exclude_patterns[i]);
+  free(scanner->exclude_patterns);
+  for (int i = 0; i < scanner->include_count; i++)
+    free(scanner->include_patterns[i]);
+  free(scanner->include_patterns);
   queue_destroy(scanner->directories);
   free(scanner);
 }
@@ -104,7 +159,7 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner) {
 
     char* cur_path = path_cat(scanner->current_path, entry->d_name);
     struct stat stats;
-    if (stat(cur_path, &stats) != 0) {
+    if (lstat(cur_path, &stats) != 0) {
       free(cur_path);
       continue;
     }

src/server/server.c

@@ -135,7 +135,6 @@ static void print_server_usage(void) {
   printf("  --ca <path>         TLS CA certificate file (PEM)\n");
   printf("  -v, --verbose       Enable debug logging\n");
   printf("  --help              Show this help\n");
-  printf("  -V, --version       Show version and exit\n");
 }
 
 int main(int argc, char* argv[]) {
@@ -150,9 +149,6 @@ int main(int argc, char* argv[]) {
     if (strcmp(argv[i], "--help") == 0) {
       print_server_usage();
       return 0;
-    } else if (strcmp(argv[i], "-V") == 0 || strcmp(argv[i], "--version") == 0) {
-      printf("fastsync-server version %s\n", PROTOCOL_VERSION);
-      return 0;
     } else if (strcmp(argv[i], "--stdio") == 0) {
       io_set_fds(STDIN_FILENO, STDOUT_FILENO);
       handler(STDIN_FILENO);

src/shared/compression.c

@@ -1,7 +1,8 @@
 #include "compression.h"
 #include "data.h"
 #include "log.h"
-#include "stdlib.h"
+#include <stdint.h>
+#include <stdlib.h>
 #include "zstd.h"
 
 #define INITIAL_DECOMPRESS_BUF_SIZE (1024 * 1024)
@@ -66,8 +67,16 @@ Data* data_decompress(Data* compressed_data) {
     return NULL;
   }
 
-  size_t buf_size =
-      (!ZSTD_isError(dst_size) && dst_size > 0) ? (size_t)dst_size : INITIAL_DECOMPRESS_BUF_SIZE;
+  size_t buf_size = INITIAL_DECOMPRESS_BUF_SIZE;
+  if (!ZSTD_isError(dst_size) && dst_size > 0) {
+    if (dst_size > SIZE_MAX) {
+      log_message(LOG_LEVEL_ERROR,
+                  "Decompressed size %llu exceeds addressable memory, using fallback buffer",
+                  dst_size);
+    } else {
+      buf_size = (size_t)dst_size;
+    }
+  }
   Data* uncompressed_data = data_create_empty(buf_size);
   if (!uncompressed_data) {
     log_message(LOG_LEVEL_ERROR, "Failed to allocate decompression buffer");

src/shared/config.c

@@ -14,8 +14,6 @@ Config* config_create(char* version, char* send_directory, char* receive_directo
                       bool use_sendfile, unsigned long long chunk_size) {
 
   Config* config = malloc(sizeof(Config));
-  if (config == NULL)
-    return NULL;
   config->version = version;
   config->send_directory = send_directory;
   config->receive_root_directory = receive_directory;

src/shared/config.h

@@ -42,7 +42,7 @@ typedef struct Config {
   char* tls_ca;
 } Config;
 
-#define PROTOCOL_VERSION "2.0.0"
+#define PROTOCOL_VERSION "1.3.0"
 #define DEFAULT_CHUNK_SIZE (10 * 1024 * 1024)
 
 Config* config_create(char* version, char* send_directory, char* receive_directory,

src/shared/data.c

@@ -1,9 +1,11 @@
 #include "data.h"
 #include "log.h"
-#include "stdlib.h"
+#include <stdlib.h>
 
 Data* data_create_empty(size_t data_size) {
-  void* data = malloc(data_size);
+  /* malloc(0) is UB; allocate at least 1 byte but preserve requested size */
+  size_t alloc_size = data_size > 0 ? data_size : 1;
+  void* data = malloc(alloc_size);
   if (data == NULL) {
     log_message(LOG_LEVEL_ERROR, "Could not allocate memory for empty data");
     return NULL;

src/shared/data.h

@@ -1,7 +1,7 @@
 #ifndef DATA_H
 #define DATA_H
 
-#include <stdlib.h>
+#include "stdlib.h"
 
 typedef struct {
   void* data;

src/shared/file.c

@@ -1,5 +1,4 @@
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <libgen.h>
 #include <stddef.h>
@@ -35,7 +34,7 @@ File* file_create(const char* path) {
     return NULL;
   }
 
-  memcpy(file->path, path, path_len + 1);
+  strcpy(file->path, path);
   file->data = data_create_reserve(0);
   if (file->data == NULL) {
     free(file->path);

src/shared/log.c

@@ -14,8 +14,7 @@ void log_message(LogLevel log_level, char* format, ...) {
   if (log_level < current_log_level)
     return;
   time_t now = time(NULL);
-  struct tm result_buf;
-  const struct tm* t = localtime_r(&now, &result_buf);
+  const struct tm* t = localtime(&now);
 
   fprintf(stderr, "%04d-%02d-%02d %02d:%02d:%02d [%s]: ", t->tm_year + 1900, t->tm_mon + 1,
           t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, log_level_strings[log_level]);

src/shared/metadata.c

@@ -4,103 +4,67 @@
 #include "protocol.h"
 #include <errno.h>
 #include <fcntl.h>
-#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <time.h>
 #include <unistd.h>
 
-/*
- * Wire format serialization (protocol version 2.0.0+):
- * All metadata fields are serialized as fixed-width integers (int32_t / int64_t)
- * to ensure cross-platform binary compatiblity.  See metadata.h for the
- * exact wire layout.
- *
- * Compile-time assertions verify that the native platform types fit within
- * the chosen fixed-width representations.
- */
-typedef char static_assert_mode_t_fits[(sizeof(mode_t) <= sizeof(int32_t)) ? 1 : -1];
-typedef char static_assert_uid_t_fits[(sizeof(uid_t) <= sizeof(int32_t)) ? 1 : -1];
-typedef char static_assert_gid_t_fits[(sizeof(gid_t) <= sizeof(int32_t)) ? 1 : -1];
-
 void metadata_to_buf(char** buf, const FileMetadata* m) {
-  int32_t present = (m != NULL) ? 1 : 0;
-  memcpy(*buf, &present, sizeof(present));
-  *buf += sizeof(present);
+  int present = (m != NULL) ? 1 : 0;
+  memcpy(*buf, &present, sizeof(int));
+  *buf += sizeof(int);
   if (m == NULL)
     return;
-  int32_t mode = (int32_t)m->mode;
-  memcpy(*buf, &mode, sizeof(mode));
-  *buf += sizeof(mode);
-  int32_t uid = (int32_t)m->uid;
-  memcpy(*buf, &uid, sizeof(uid));
-  *buf += sizeof(uid);
-  int32_t gid = (int32_t)m->gid;
-  memcpy(*buf, &gid, sizeof(gid));
-  *buf += sizeof(gid);
-  int64_t mtime_sec = (int64_t)m->mtime_sec;
-  memcpy(*buf, &mtime_sec, sizeof(mtime_sec));
-  *buf += sizeof(mtime_sec);
-  int64_t mtime_nsec = (int64_t)m->mtime_nsec;
-  memcpy(*buf, &mtime_nsec, sizeof(mtime_nsec));
-  *buf += sizeof(mtime_nsec);
+  memcpy(*buf, &m->mode, sizeof(mode_t));
+  *buf += sizeof(mode_t);
+  memcpy(*buf, &m->uid, sizeof(uid_t));
+  *buf += sizeof(uid_t);
+  memcpy(*buf, &m->gid, sizeof(gid_t));
+  *buf += sizeof(gid_t);
+  memcpy(*buf, &m->mtime_sec, sizeof(time_t));
+  *buf += sizeof(time_t);
+  memcpy(*buf, &m->mtime_nsec, sizeof(long));
+  *buf += sizeof(long);
 }
 
 FileMetadata* metadata_from_buf(char** buf) {
-  int32_t present;
-  memcpy(&present, *buf, sizeof(present));
-  *buf += sizeof(present);
+  int present;
+  memcpy(&present, *buf, sizeof(int));
+  *buf += sizeof(int);
   if (!present)
     return NULL;
   FileMetadata* m = malloc(sizeof(FileMetadata));
-  if (m == NULL)
-    return NULL;
-  int32_t mode;
-  memcpy(&mode, *buf, sizeof(mode));
-  *buf += sizeof(mode);
-  m->mode = (mode_t)mode;
-  int32_t uid;
-  memcpy(&uid, *buf, sizeof(uid));
-  *buf += sizeof(uid);
-  m->uid = (uid_t)uid;
-  int32_t gid;
-  memcpy(&gid, *buf, sizeof(gid));
-  *buf += sizeof(gid);
-  m->gid = (gid_t)gid;
-  int64_t mtime_sec;
-  memcpy(&mtime_sec, *buf, sizeof(mtime_sec));
-  *buf += sizeof(mtime_sec);
-  m->mtime_sec = (time_t)mtime_sec;
-  int64_t mtime_nsec;
-  memcpy(&mtime_nsec, *buf, sizeof(mtime_nsec));
-  *buf += sizeof(mtime_nsec);
-  m->mtime_nsec = (long)mtime_nsec;
+  memcpy(&m->mode, *buf, sizeof(mode_t));
+  *buf += sizeof(mode_t);
+  memcpy(&m->uid, *buf, sizeof(uid_t));
+  *buf += sizeof(uid_t);
+  memcpy(&m->gid, *buf, sizeof(gid_t));
+  *buf += sizeof(gid_t);
+  memcpy(&m->mtime_sec, *buf, sizeof(time_t));
+  *buf += sizeof(time_t);
+  memcpy(&m->mtime_nsec, *buf, sizeof(long));
+  *buf += sizeof(long);
   return m;
 }
 
 bool metadata_send(int file_descriptor, FileMetadata* m) {
   if (m == NULL) {
-    int32_t zero = 0;
-    return send_n_data(file_descriptor, &zero, sizeof(zero));
+    int zero = 0;
+    return send_n_data(file_descriptor, &zero, sizeof(int));
   }
-  int32_t present = 1;
-  int32_t mode = (int32_t)m->mode;
-  int32_t uid = (int32_t)m->uid;
-  int32_t gid = (int32_t)m->gid;
-  int64_t mtime_sec = (int64_t)m->mtime_sec;
-  int64_t mtime_nsec = (int64_t)m->mtime_nsec;
-  return send_n_data(file_descriptor, &present, sizeof(present)) &&
-         send_n_data(file_descriptor, &mode, sizeof(mode)) &&
-         send_n_data(file_descriptor, &uid, sizeof(uid)) &&
-         send_n_data(file_descriptor, &gid, sizeof(gid)) &&
-         send_n_data(file_descriptor, &mtime_sec, sizeof(mtime_sec)) &&
-         send_n_data(file_descriptor, &mtime_nsec, sizeof(mtime_nsec));
+  int present = 1;
+  return send_n_data(file_descriptor, &present, sizeof(int)) &&
+         send_n_data(file_descriptor, &m->mode, sizeof(mode_t)) &&
+         send_n_data(file_descriptor, &m->uid, sizeof(uid_t)) &&
+         send_n_data(file_descriptor, &m->gid, sizeof(gid_t)) &&
+         send_n_data(file_descriptor, &m->mtime_sec, sizeof(time_t)) &&
+         send_n_data(file_descriptor, &m->mtime_nsec, sizeof(long));
 }
 
 FileMetadata* metadata_receive(int file_descriptor, int* ok) {
-  int32_t present;
-  if (!receive_n_data(file_descriptor, &present, sizeof(present))) {
+  int present;
+  if (!receive_n_data(file_descriptor, &present, sizeof(int))) {
     if (ok)
       *ok = 0;
     return NULL;
@@ -116,46 +80,16 @@ FileMetadata* metadata_receive(int file_descriptor, int* ok) {
       *ok = 0;
     return NULL;
   }
-  int32_t mode;
-  if (!receive_n_data(file_descriptor, &mode, sizeof(mode))) {
+  if (!receive_n_data(file_descriptor, &m->mode, sizeof(mode_t)) ||
+      !receive_n_data(file_descriptor, &m->uid, sizeof(uid_t)) ||
+      !receive_n_data(file_descriptor, &m->gid, sizeof(gid_t)) ||
+      !receive_n_data(file_descriptor, &m->mtime_sec, sizeof(time_t)) ||
+      !receive_n_data(file_descriptor, &m->mtime_nsec, sizeof(long))) {
     free(m);
     if (ok)
       *ok = 0;
     return NULL;
   }
-  m->mode = (mode_t)mode;
-  int32_t uid;
-  if (!receive_n_data(file_descriptor, &uid, sizeof(uid))) {
-    free(m);
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
-  m->uid = (uid_t)uid;
-  int32_t gid;
-  if (!receive_n_data(file_descriptor, &gid, sizeof(gid))) {
-    free(m);
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
-  m->gid = (gid_t)gid;
-  int64_t mtime_sec;
-  if (!receive_n_data(file_descriptor, &mtime_sec, sizeof(mtime_sec))) {
-    free(m);
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
-  m->mtime_sec = (time_t)mtime_sec;
-  int64_t mtime_nsec;
-  if (!receive_n_data(file_descriptor, &mtime_nsec, sizeof(mtime_nsec))) {
-    free(m);
-    if (ok)
-      *ok = 0;
-    return NULL;
-  }
-  m->mtime_nsec = (long)mtime_nsec;
   if (ok)
     *ok = 1;
   return m;

src/shared/metadata.h

@@ -3,24 +3,10 @@
 
 #include "file.h"
 #include <stdbool.h>
-#include <stdint.h>
 #include <sys/stat.h>
 
-/*
- * Wire format (introduced in protocol version 2.0.0):
- *   int32_t present
- *   int32_t mode    (was mode_t, platform-dependent)
- *   int32_t uid     (was uid_t,  platform-dependent)
- *   int32_t gid     (was gid_t,  platform-dependent)
- *   int64_t mtime_sec (was time_t, platform-dependent)
- *   int64_t mtime_nsec (was long,  platform-dependent)
- *
- * Prior to 2.0.0 the wire format used the raw platform-dependent types,
- * which broke compatiblity across different systems.  All fields are now
- * serialized as fixed-width integers.
- */
-
-#define FILE_METADATA_WIRE_SIZE (sizeof(int32_t) * 3 + sizeof(int64_t) * 2)
+#define FILE_METADATA_WIRE_SIZE                                                                    \
+  (sizeof(mode_t) + sizeof(uid_t) + sizeof(gid_t) + sizeof(time_t) + sizeof(long))
 
 void metadata_to_buf(char** buf, const FileMetadata* m);
 FileMetadata* metadata_from_buf(char** buf);

src/shared/protocol.c

@@ -138,6 +138,10 @@ static const char* status_to_string(Status status) {
 }
 
 bool send_str(int file_descriptor, const char* data) {
+  if (data == NULL) {
+    log_message(LOG_LEVEL_ERROR, "send_str called with NULL data");
+    return false;
+  }
   size_t size = strlen(data);
   if (!send_n_data(file_descriptor, &size, sizeof(size_t)))
     return false;
@@ -151,6 +155,11 @@ 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, "receive_str: size %zu exceeds maximum %zu", size,
+                (size_t)MAX_STRING_SIZE);
+    return NULL;
+  }
   char* data = (char*)malloc(size + 1);
   if (data == NULL)
     return NULL;
@@ -169,14 +178,20 @@ bool send_data(int file_descriptor, const Data* data) {
     return false;
   if (!send_n_data(file_descriptor, data->data, data_size))
     return false;
-  log_message(LOG_LEVEL_DEBUG, "Send %lld data", data_size);
+  log_message(LOG_LEVEL_DEBUG, "Send %llu data", data_size);
   return true;
 }
 
+#define MAX_DATA_SIZE (1024ULL * 1024 * 1024)
+
 Data* receive_data(int file_descriptor) {
   unsigned long long size = 0;
   if (!receive_n_data(file_descriptor, &size, sizeof(unsigned long long)))
     return NULL;
+  if ((size_t)size != size || size > MAX_DATA_SIZE) {
+    log_message(LOG_LEVEL_ERROR, "receive_data size %llu exceeds limits", size);
+    return NULL;
+  }
   void* data = malloc((size_t)size);
   if (data == NULL)
     return NULL;
@@ -184,7 +199,7 @@ Data* receive_data(int file_descriptor) {
     free(data);
     return NULL;
   }
-  log_message(LOG_LEVEL_DEBUG, "Received %lld data", size);
+  log_message(LOG_LEVEL_DEBUG, "Received %llu data", size);
   return data_create(data, (size_t)size);
 }
 

src/shared/protocol.h

@@ -5,6 +5,9 @@
 #include <stdbool.h>
 #include <stddef.h>
 
+/* Maximum allowed string size for receive_str (10 MB) */
+#define MAX_STRING_SIZE (10 * 1024 * 1024)
+
 typedef struct ssl_st SSL;
 
 typedef int Status;

src/shared/transport_ssh.c

@@ -124,7 +124,10 @@ Client* client_connect_ssh(const char* destination, int port) {
     else
       snprintf(ssh_user, sizeof(ssh_user), "%s", r.host);
 
-    char* ssh_argv[16];
+    size_t ssh_argv_max = 32;
+    char** ssh_argv = calloc(ssh_argv_max, sizeof(char*));
+    if (ssh_argv == NULL)
+      _exit(1);
     int ac = 0;
     char port_str[16];
     ssh_argv[ac++] = "ssh";
@@ -135,10 +138,14 @@ Client* client_connect_ssh(const char* destination, int port) {
     ssh_argv[ac++] = "-o";
     ssh_argv[ac++] = "ControlPath=~/.cache/fastsync-%r@%h:%p";
     if (port > 0 && port != 22) {
+      if ((size_t)ac + 2 >= ssh_argv_max)
+        _exit(1);
       ssh_argv[ac++] = "-p";
       snprintf(port_str, sizeof(port_str), "%d", port);
       ssh_argv[ac++] = port_str;
     }
+    if ((size_t)ac + 3 >= ssh_argv_max)
+      _exit(1);
     ssh_argv[ac++] = ssh_user;
     ssh_argv[ac++] = "fastsync-server";
     ssh_argv[ac++] = "--stdio";

src/shared/utils.c

@@ -10,19 +10,23 @@
 #include <unistd.h>
 
 bool mkdir_r(const char* path) {
-  char* path_duplicate = malloc(strlen(path) + 1);
+  size_t path_len = strlen(path);
+  char* path_duplicate = malloc(path_len + 1);
   if (!path_duplicate)
     return false;
-  strcpy(path_duplicate, path);
-  char* path_current = (char*)malloc((strlen(path) + 2) * sizeof(char));
+  memcpy(path_duplicate, path, path_len + 1);
+  /* Buffer for building subpaths: path_len + 1 for leading '/' + 1 for null */
+  size_t buf_size = path_len + 2;
+  char* path_current = (char*)malloc(buf_size);
   if (!path_current) {
     free(path_duplicate);
     return false;
   }
-  char* path_current_position = path_current;
+  size_t pos = 0;
   if (path[0] == '/') {
-    strcpy(path_current, "/");
-    path_current_position += 1;
+    path_current[0] = '/';
+    path_current[1] = '\0';
+    pos = 1;
   } else {
     path_current[0] = '\0';
   }
@@ -31,10 +35,16 @@ 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);
+    if (pos + part_len + 1 >= buf_size) {
+      ok = false;
+      break;
+    }
+    memcpy(path_current + pos, part, part_len);
+    pos += part_len;
+    path_current[pos] = '/';
+    pos++;
+    path_current[pos] = '\0';
     struct stat st;
     if (stat(path_current, &st) != 0) {
       if (mkdir(path_current, 0755) != 0) {
@@ -49,12 +59,11 @@ bool mkdir_r(const char* path) {
   free(path_current);
   return ok;
 }
-
 char* str_dup(const char* string) {
   if (string == NULL)
     return NULL;
   char* new_string = (char*)malloc(strlen(string) + 1);
-  memcpy(new_string, string, strlen(string) + 1);
+  strcpy(new_string, string);
   return new_string;
 }
 
@@ -99,7 +108,7 @@ static void delete_extras_walk(const char* abs_path, const char* rel_path, Array
   if (!dir)
     return;
   bool all_removed = true;
-  struct dirent* entry;
+  const struct dirent* entry;
   while ((entry = readdir(dir)) != NULL) {
     if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
       continue;
@@ -149,18 +158,17 @@ void delete_extras(const char* dest_root, ArrayList* manifest) {
   delete_extras_walk(dest_root, "", manifest);
 }
 
-char* path_cat(const char* path1, char* path2) {
+char* path_cat(const char* path1, const char* path2) {
   if (path1 == NULL || *path1 == '\0')
     return str_dup(path2);
   if (path2 == NULL || *path2 == '\0')
     return str_dup(path1);
   int path1_len = strlen(path1);
   int path2_len = strlen(path2);
-  char* path2_pointer = path2;
   if (path1[path1_len - 1] == '/')
     path1_len -= 1;
   if (path2[0] == '/') {
-    path2_pointer += 1;
+    path2++;
     path2_len -= 1;
   }
   char* new_path = malloc(path1_len + path2_len + 2);
@@ -168,7 +176,7 @@ char* path_cat(const char* path1, char* path2) {
     return NULL;
   memcpy(new_path, path1, path1_len);
   new_path[path1_len] = '/';
-  memcpy(new_path + path1_len + 1, path2_pointer, path2_len);
+  memcpy(new_path + path1_len + 1, path2, path2_len);
   new_path[path1_len + path2_len + 1] = '\0';
   return new_path;
 }

src/shared/utils.h

@@ -6,7 +6,7 @@
 
 bool mkdir_r(const char* path);
 char* str_dup(const char* string);
-char* path_cat(const char* path1, char* path2);
+char* path_cat(const char* path1, const char* path2);
 bool glob_match(const char* pattern, const char* str);
 void delete_extras(const char* dest_root, ArrayList* manifest);
 

tests/test_data.c

@@ -23,6 +23,14 @@ static void test_data_create_empty() {
   data_destroy(d);
 }
 
+static void test_data_create_empty_zero() {
+  Data* d = data_create_empty(0);
+  EXPECT_NOT_NULL(d);
+  EXPECT_NOT_NULL(d->data);
+  EXPECT_EQ_INT((int)d->size, 0);
+  data_destroy(d);
+}
+
 static void test_data_create_reserve() {
   Data* d = data_create_reserve(1024);
   EXPECT_NOT_NULL(d);
@@ -44,6 +52,7 @@ static void test_data_destroy_normal() {
 void test_data() {
   test_data_create();
   test_data_create_empty();
+  test_data_create_empty_zero();
   test_data_create_reserve();
   test_data_destroy_null();
   test_data_destroy_normal();

tests/test_protocol.c

@@ -169,6 +169,23 @@ static void test_receive_str_truncated() {
   close(p[0]);
 }
 
+static void test_receive_str_oversized() {
+  int p[2];
+  EXPECT_EQ_INT(pipe(p), 0);
+  io_set_fds(p[0], p[1]);
+  io_set_bwlimit(0);
+
+  /* Send a size exceeding MAX_STRING_SIZE */
+  size_t huge = MAX_STRING_SIZE + 1;
+  EXPECT_TRUE(send_n_data(0, &huge, sizeof(size_t)));
+
+  const char* received = receive_str(0);
+  EXPECT_NULL(received);
+
+  close(p[0]);
+  close(p[1]);
+}
+
 void test_protocol() {
   test_send_receive_n_data();
   test_send_receive_n_data_zero();
@@ -179,4 +196,5 @@ void test_protocol() {
   test_send_receive_status();
   test_receive_n_data_truncated();
   test_receive_str_truncated();
+  test_receive_str_oversized();
 }