agent: implement connection loop with retry

agent/agent.c

@@ -83,10 +83,11 @@ static void signal_handler(int sig)
 static void agent_shutdown(void)
 {
 	printf("Shutting down agent...\n");
-	SSL_shutdown(ssl);
-	SSL_free(ssl);
-	SSL_CTX_free(ctx);		/* release context */
+	if (ssl) SSL_shutdown(ssl);
+	if (ssl) SSL_free(ssl);
+	if (ctx) SSL_CTX_free(ctx);	/* release context */
 	close(server);			/* close socket */
+	_exit(EXIT_SUCCESS);
 }
 
 static void set_env(void)
@@ -116,7 +117,7 @@ static void set_env(void)
 
 int main(int count, char *strings[])
 {
-	int bytes, i;
+	int bytes, i, err;
 	char *hostname, *portnum;
 
 	if (count != 6) {
@@ -127,10 +128,14 @@ int main(int count, char *strings[])
 	portnum=strings[2];
 	if ((ctx = init_ctx()) == NULL)
 		_exit(EXIT_FAILURE);
+
+	while (1) {
 		server = connect_to_rmps(hostname, atoi(portnum));
 		if (!server) {
-		fprintf(stderr, "Failed to connect to RMPS: %s:%d\n", hostname, atoi(portnum));
-		_exit(EXIT_FAILURE);
+			fprintf(stderr, "Failed to connect to RMPS on %s:%d - %s\n", hostname, atoi(portnum), strerror(errno));
+			printf("Retrying...\n");
+			sleep(5);
+			continue;
 		}
 		load_certs(ctx, strings[3], strings[4], strings[5]);
 		ssl = SSL_new(ctx);		/* create new SSL connection state */
@@ -181,7 +186,8 @@ int main(int count, char *strings[])
 				if (bytes != sizeof(struct msg_t)) {
 					fprintf( stderr,
 						 "Received non-standard data from server!\n" );
-				continue;
+					//conntinue;
+					return 1;
 				}
 				if (buf.chunk.id == 0) {
 					if ((index = get_job_slot()) == FAIL) {
@@ -281,4 +287,30 @@ int main(int count, char *strings[])
 			SSL_shutdown(ssl);
 			SSL_free(ssl);		/* release connection state */
 		} while (bytes);
+		if (SSL_get_shutdown(ssl)) {
+			printf("RMPS server has shutdown, trying to reconnect...\n");
+			sleep(5);
+		} else {
+			err = SSL_get_error(ssl, bytes);
+				switch (err) {
+				case SSL_ERROR_WANT_WRITE:
+				printf("want_write\n");
+					return 0;
+				case SSL_ERROR_WANT_READ:
+				printf("want_read\n");
+					return 0;
+				case SSL_ERROR_ZERO_RETURN:
+				printf("zero_return\n");
+					return -1;
+				case SSL_ERROR_SYSCALL:
+				printf("syscall\n");
+					return -1;
+				case SSL_ERROR_SSL:
+				printf("ssl\n");
+					return -1;
+				default:
+					return -1;
+			}
+		}
+	}
 }

agent/agent_ssl.c

@@ -49,7 +49,6 @@ int connect_to_rmps(const char *hostname, int port)
     	addr.sin_addr.s_addr = *(long*)(host->h_addr);
     	if (connect(sd, (struct sockaddr*)&addr, sizeof(addr)) == FAIL) {
 		close(sd);
-		perror(hostname);
 		return 0;
     	}
     	return sd;