Merge "res_stasis_recording: Allow symbolic links in configured recordings dir."

res/stasis_recording/stored.c

@@ -330,6 +330,7 @@ struct stasis_app_stored_recording *stasis_app_stored_recording_find_by_name(
 	RAII_VAR(char *, file_with_ext, NULL, ast_free);
 	int res;
 	struct stat file_stat;
+	int prefix_len = strlen(ast_config_AST_RECORDING_DIR);
 
 	errno = 0;
 
@@ -350,18 +351,28 @@ struct stasis_app_stored_recording *stasis_app_stored_recording_find_by_name(
 	ast_string_field_build(recording, file, "%s/%s", dir, file);
 
 	if (!ast_begins_with(dir, ast_config_AST_RECORDING_DIR)) {
-		/* Attempt to escape the recording directory */
-		ast_log(LOG_WARNING, "Attempt to access invalid recording %s\n",
-			name);
-		errno = EACCES;
-		return NULL;
+		/* It's possible that one or more component of the recording path is
+		 * a symbolic link, this would prevent dir from ever matching. */
+		char *real_basedir = realpath(ast_config_AST_RECORDING_DIR, NULL);
+
+		if (!real_basedir || !ast_begins_with(dir, real_basedir)) {
+			/* Attempt to escape the recording directory */
+			ast_log(LOG_WARNING, "Attempt to access invalid recording directory %s\n",
+				dir);
+			ast_std_free(real_basedir);
+			errno = EACCES;
+
+			return NULL;
+		}
+
+		prefix_len = strlen(real_basedir);
+		ast_std_free(real_basedir);
 	}
 
 	/* The actual name of the recording is file with the config dir
 	 * prefix removed.
 	 */
-	ast_string_field_set(recording, name,
-		recording->file + strlen(ast_config_AST_RECORDING_DIR) + 1);
+	ast_string_field_set(recording, name, recording->file + prefix_len + 1);
 
 	file_with_ext = find_recording(dir, file);
 	if (!file_with_ext) {