improved error checking and reporting for reading and writing time and date

jsonrtc/src/jsonrtc.c

@@ -21,44 +21,52 @@ page(struct http_request *req)
 int handle_time(struct http_request *req) {
 	int fdesc;
 	struct rtc_time time;
+	int ret;
+	char *msg;
 	cJSON *time_json, *json_min, *json_hour, *json_mday,
 		*json_mon, *json_year, *json_sec, *json_wday;
 	if(req->method == HTTP_METHOD_GET) {
 		char *result_string;
 		time_json = cJSON_CreateObject();
 		fdesc = open("/dev/rtc", O_RDONLY);
-		ioctl(fdesc, RTC_RD_TIME, &time);
+		ret = ioctl(fdesc, RTC_RD_TIME, &time);
 		close(fdesc);
-		json_sec = cJSON_CreateNumber(time.tm_sec);
-		json_min = cJSON_CreateNumber(time.tm_min);
-		json_hour = cJSON_CreateNumber(time.tm_hour);
-		json_mday = cJSON_CreateNumber(time.tm_mday);
-		json_mon = cJSON_CreateNumber(time.tm_mon);
-		json_year = cJSON_CreateNumber(time.tm_year);
-		json_wday = cJSON_CreateNumber(time.tm_wday);
-		cJSON_AddItemToObject(time_json, "seconds", json_sec);
-		cJSON_AddItemToObject(time_json, "minutes", json_min);
-		cJSON_AddItemToObject(time_json, "hour", json_hour);
-		cJSON_AddItemToObject(time_json, "mday", json_mday);
-		cJSON_AddItemToObject(time_json, "month", json_mon);
-		cJSON_AddItemToObject(time_json, "year", json_year);
-		cJSON_AddItemToObject(time_json, "wday", json_wday);
-		result_string = cJSON_Print(time_json);
+		if (!ret) {
+			json_sec = cJSON_CreateNumber(time.tm_sec);
+			json_min = cJSON_CreateNumber(time.tm_min);
+			json_hour = cJSON_CreateNumber(time.tm_hour);
+			json_mday = cJSON_CreateNumber(time.tm_mday);
+			json_mon = cJSON_CreateNumber(time.tm_mon);
+			json_year = cJSON_CreateNumber(time.tm_year);
+			json_wday = cJSON_CreateNumber(time.tm_wday);
+			cJSON_AddItemToObject(time_json, "seconds", json_sec);
+			cJSON_AddItemToObject(time_json, "minutes", json_min);
+			cJSON_AddItemToObject(time_json, "hour", json_hour);
+			cJSON_AddItemToObject(time_json, "mday", json_mday);
+			cJSON_AddItemToObject(time_json, "month", json_mon);
+			cJSON_AddItemToObject(time_json, "year", json_year);
+			cJSON_AddItemToObject(time_json, "wday", json_wday);
+			result_string = cJSON_Print(time_json);
+			cJSON_Delete(time_json);
+			http_response_header(req, "Content-Type", "application/json");
+			http_response(req, 200, result_string, strlen(result_string));
+			return KORE_RESULT_OK;
+		}
 		cJSON_Delete(time_json);
-		http_response_header(req, "Content-Type", "application/json");
-		http_response(req, 200, result_string, strlen(result_string));
+		msg = "Error: could not get time from /dev/rtc\n";
+		http_response(req, 200, msg, strlen(msg));
 		return KORE_RESULT_OK;
 	} else if (req->method == HTTP_METHOD_POST) {
 		struct kore_buf * buf;
 		u_int8_t data[128];
-		int ret;
 		char * body;
 		buf = kore_buf_alloc(128);
 		while(1) {
 			ret = http_body_read(req, data, sizeof(data));
 			if (ret == -1) {
 				kore_buf_free(buf);
-				http_response(req, 500, NULL, 0);
+				msg = "Error: could not read body data\n";
+				http_response(req, 500, msg, strlen(msg));
 				return (KORE_RESULT_OK);
 			}
 			if (ret == 0) {
@@ -70,7 +78,8 @@ int handle_time(struct http_request *req) {
 		kore_buf_free(buf);
 		time_json = cJSON_Parse(body);
 		if (time_json == NULL) {
-			http_response(req, 500, NULL, 0);
+			msg = "Error: could not parse json\n";
+			http_response(req, 500, msg, strlen(msg));
 			return (KORE_RESULT_OK);
 		}
 		json_sec = cJSON_GetObjectItemCaseSensitive(time_json, "seconds");
@@ -92,7 +101,8 @@ int handle_time(struct http_request *req) {
 			time.tm_wday = json_wday->valueint;
 		} else {
 			cJSON_Delete(time_json);
-			http_response(req, 500, NULL, 0);
+			msg = "Error: invalid or missing values in json object\n";
+			http_response(req, 500, msg, strlen(msg));
                         return (KORE_RESULT_OK);
 		}
 		cJSON_Delete(time_json);
@@ -100,7 +110,8 @@ int handle_time(struct http_request *req) {
 		ret = ioctl(fdesc, RTC_SET_TIME, &time);
 		close(fdesc);
 		if (ret) {
-			http_response(req, 500, NULL, 0);
+			msg = "Error: Could not set time via /dev/rtc\n";
+			http_response(req, 500, msg, strlen(msg));
                         return (KORE_RESULT_OK);
 		}
                 http_response(req, 200, NULL, 0);