-/*
- Read exactly one line and strip the trailing newline if any. If the
- file was on EOF, return NULL. Otherwise, return all the data in a
- dynamically allocated buffer.
-
- If line is non-NULL, it will be used as an initial buffer, to avoid
- unnecessary mallocing each time this function is called. If buf is
- given, and buf needs to be expanded, the var pointed to by buflen
- will be increased.
-*/
-char *readline(FILE * fp, char **buf, size_t * buflen)
-{
- char *newline = NULL;
- char *p;
- char *line; /* The array that contains everything that has been read so far */
- char *idx; /* Read into this pointer, which points to an offset within line */
- size_t size, newsize; /* The size of the current array pointed to by line */
- size_t maxlen; /* Maximum number of characters that may be read with fgets. This is newsize - oldsize. */
-
- if(feof(fp))
- return NULL;
-
- if(buf && buflen) {
- size = *buflen;
- line = *buf;
- } else {
- size = 100;
- line = xmalloc(size);
- }
-
- maxlen = size;
- idx = line;
- *idx = 0;
-
- for(;;) {
- errno = 0;
- p = fgets(idx, maxlen, fp);
-
- if(!p) { /* EOF or error */
- if(feof(fp))
- break;
-
- /* otherwise: error; let the calling function print an error message if applicable */
- free(line);
- return NULL;
+/// Lock the main configuration file.
+bool main_config_lock(meshlink_handle_t *mesh) {
+ if(!mesh->confbase) {
+ return true;
+ }
+
+ char path[PATH_MAX];
+ make_main_path(mesh, "current", path, sizeof(path));
+
+ mesh->conffile = fopen(path, "r");
+
+ if(!mesh->conffile) {
+ logger(NULL, MESHLINK_ERROR, "Cannot not open %s: %s\n", path, strerror(errno));
+ meshlink_errno = MESHLINK_ESTORAGE;
+ return false;
+ }
+
+#ifdef FD_CLOEXEC
+ fcntl(fileno(mesh->conffile), F_SETFD, FD_CLOEXEC);
+#endif
+
+#ifdef HAVE_MINGW
+ // TODO: use _locking()?
+#else
+
+ if(flock(fileno(mesh->conffile), LOCK_EX | LOCK_NB) != 0) {
+ logger(NULL, MESHLINK_ERROR, "Cannot lock %s: %s\n", path, strerror(errno));
+ fclose(mesh->conffile);
+ mesh->conffile = NULL;
+ meshlink_errno = MESHLINK_EBUSY;
+ return false;
+ }
+
+#endif
+
+ return true;
+}
+
+/// Unlock the main configuration file.
+void main_config_unlock(meshlink_handle_t *mesh) {
+ if(mesh->conffile) {
+ fclose(mesh->conffile);
+ mesh->conffile = NULL;
+ }
+}
+
+/// Read a configuration file from a FILE handle.
+bool config_read_file(meshlink_handle_t *mesh, FILE *f, config_t *config, const void *key) {
+ assert(f);
+
+ long len;
+
+ if(fseek(f, 0, SEEK_END) || !(len = ftell(f)) || fseek(f, 0, SEEK_SET)) {
+ logger(mesh, MESHLINK_ERROR, "Cannot get config file size: %s\n", strerror(errno));
+ meshlink_errno = MESHLINK_ESTORAGE;
+ return false;
+ }
+
+ uint8_t *buf = xmalloc(len);
+
+ if(fread(buf, len, 1, f) != 1) {
+ logger(mesh, MESHLINK_ERROR, "Cannot read config file: %s\n", strerror(errno));
+ meshlink_errno = MESHLINK_ESTORAGE;
+ return false;
+ }
+
+ if(key) {
+ uint8_t *decrypted = xmalloc(len);
+ size_t decrypted_len = len;
+ chacha_poly1305_ctx_t *ctx = chacha_poly1305_init();
+ chacha_poly1305_set_key(ctx, key);
+
+ if(len > 12 && chacha_poly1305_decrypt_iv96(ctx, buf, buf + 12, len - 12, decrypted, &decrypted_len)) {
+ chacha_poly1305_exit(ctx);
+ free(buf);
+ config->buf = decrypted;
+ config->len = decrypted_len;
+ return true;
+ } else {
+ logger(mesh, MESHLINK_ERROR, "Cannot decrypt config file\n");
+ meshlink_errno = MESHLINK_ESTORAGE;
+ chacha_poly1305_exit(ctx);
+ free(decrypted);
+ free(buf);
+ return false;