fix: const qualifier for dirent pointer (cppcheck)

Reviewed-on: #86

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/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/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/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) {
@@ -49,7 +59,6 @@ bool mkdir_r(const char* path) {
   free(path_current);
   return ok;
 }
-
 char* str_dup(const char* string) {
   if (string == NULL)
     return NULL;
@@ -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_file.c

@@ -271,7 +271,7 @@ void test_file() {
   test_to_disk_basic();
   test_to_disk_creates_dirs();
   test_file_content_to_buffer();
-  if (!getenv("FASTSYNC_UNDER_VALGRIND")) {
+  if (!is_running_under_valgrind()) {
     // Fork tests are skipped under valgrind because the parent process runs
     // orders of magnitude slower than the child (parent is instrumented, child
     // is not), which causes pipe-based protocol handshake timeouts. The parent

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();
 }

tests/test_utils.h

@@ -2,9 +2,24 @@
 #define TEST_UTILS_H
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
 
+// Detect if running under valgrind by checking /proc/self/maps for vgpreload.
+// This is used to skip fork-based tests that are incompatible with valgrind
+// (the instrumented parent runs too slowly, causing pipe timeouts).
+static inline bool is_running_under_valgrind(void) {
+  FILE* f = fopen("/proc/self/maps", "r");
+  if (!f)
+    return false;
+  char buf[4096];
+  size_t n = fread(buf, 1, sizeof(buf) - 1, f);
+  fclose(f);
+  buf[n] = '\0';
+  return strstr(buf, "vgpreload") != NULL;
+}
+
 // Global test suite status
 extern int tests_run;
 extern int tests_failed;