tee-supplicant: Support multiple ta load paths

CFG_TEE_CLIENT_LOAD_PATH can have multiple paths separated by :

Author: chao-amazon

config.mk

@@ -31,6 +31,8 @@ CFG_TEE_CLIENT_LOG_FILE ?= $(CFG_TEE_FS_PARENT_PATH)/teec.log
 
 # CFG_TEE_CLIENT_LOAD_PATH
 #   The location of the client library file.
+#   Suport multiple ta load path
+#   CFG_TEE_CLIENT_LOAD_PATH ?= /lib:/vendor/lib
 CFG_TEE_CLIENT_LOAD_PATH ?= /lib
 
 # CFG_TEE_SUPP_PLUGINS

tee-supplicant/src/teec_ta_load.c

@@ -172,19 +172,48 @@ static int try_load_secure_module(const char* prefix,
 	return TA_BINARY_FOUND;
 }
 
+/* support multiple ta load path */
+static int load_secure_module_multipath(const char* multi_prefix,
+				  const char* dev_path,
+				  const TEEC_UUID *destination, void *ta,
+				  size_t *ta_size)
+{
+	char *multi_path = NULL;
+	char *single_path = NULL;
+	char *tofree = NULL;
+	int res = 0;
+
+	multi_path = strdup(multi_prefix);
+	if (!multi_path) {
+		EMSG("out of memory");
+		return -1;
+	}
+
+	tofree = multi_path;
+	while ((single_path = strsep(&multi_path, ":")) != NULL) {
+		res = try_load_secure_module(single_path,
+				dev_path, destination, ta, ta_size);
+		if (res == TA_BINARY_FOUND)
+			break;
+	}
+	free(tofree);
+
+	return res;
+}
+
 int TEECI_LoadSecureModule(const char* dev_path,
 			   const TEEC_UUID *destination, void *ta,
 			   size_t *ta_size)
 {
 #ifdef TEEC_TEST_LOAD_PATH
 	int res = 0;
 
-	res = try_load_secure_module(TEEC_TEST_LOAD_PATH,
+	res = load_secure_module_multipath(TEEC_TEST_LOAD_PATH,
 				     dev_path, destination, ta, ta_size);
 	if (res != TA_BINARY_NOT_FOUND)
 		return res;
 #endif
 
-	return try_load_secure_module(TEEC_LOAD_PATH,
+	return load_secure_module_multipath(TEEC_LOAD_PATH,
 				      dev_path, destination, ta, ta_size);
 }