commands: handle EINTR

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/commands_utils.c

@@ -45,22 +45,28 @@ int lxc_cmd_sock_rcv_state(int state_client_fd, int timeout)
 	struct lxc_msg msg;
 	struct timeval out;
 
-	memset(&out, 0, sizeof(out));
-	out.tv_sec = timeout;
-	ret = setsockopt(state_client_fd, SOL_SOCKET, SO_RCVTIMEO,
-			 (const void *)&out, sizeof(out));
-	if (ret < 0) {
-		SYSERROR("Failed to set %ds timeout on containter state socket", timeout);
-		return -1;
+	if (timeout >= 0) {
+		memset(&out, 0, sizeof(out));
+		out.tv_sec = timeout;
+		ret = setsockopt(state_client_fd, SOL_SOCKET, SO_RCVTIMEO,
+				(const void *)&out, sizeof(out));
+		if (ret < 0) {
+			SYSERROR("Failed to set %ds timeout on containter "
+				 "state socket",
+				 timeout);
+			return -1;
+		}
 	}
 
 	memset(&msg, 0, sizeof(msg));
 
 again:
 	ret = recv(state_client_fd, &msg, sizeof(msg), 0);
 	if (ret < 0) {
-		if (errno == EINTR)
+		if (errno == EINTR) {
+			TRACE("Caught EINTR; retrying");
 			goto again;
+		}
 
 		ERROR("failed to receive message: %s", strerror(errno));
 		return -1;

src/lxc/lxccontainer.c

@@ -702,7 +702,7 @@ static void free_init_cmd(char **argv)
 static int lxc_rcv_status(int state_socket)
 {
         int ret;
-        lxc_state_t state = -1;
+        int state = -1;
         struct timeval timeout = {0};
 
         /* Set 5 second timeout to prevent hanging forever in case something
@@ -716,14 +716,16 @@ static int lxc_rcv_status(int state_socket)
                 return -1;
         }
 
+again:
         /* Receive container state. */
         ret = lxc_abstract_unix_rcv_credential(state_socket, &state,
-                                               sizeof(lxc_state_t));
-        /* Close container state client. */
-        close(state_socket);
-
-        if (ret <= 0)
-                return -1;
+                                               sizeof(int));
+        if (ret <= 0) {
+		if (errno != EINTR)
+			return -1;
+		TRACE("Caught EINTR; retrying");
+		goto again;
+	}
 
         return state;
 }

src/lxc/start.c

@@ -384,9 +384,11 @@ static int lxc_serve_state_clients(const char *name,
 
 	again:
 		ret = send(client->clientfd, &msg, sizeof(msg), 0);
-		if (ret < 0) {
-			if (errno == EINTR)
+		if (ret <= 0) {
+			if (errno == EINTR) {
+				TRACE("Caught EINTR; retrying");
 				goto again;
+			}
 
 			ERROR("failed to send message to client");
 		}
@@ -417,11 +419,16 @@ static int lxc_serve_state_socket_pair(const char *name,
 	close(handler->state_socket_pair[0]);
 	handler->state_socket_pair[0] = -1;
 
+again:
 	ret = lxc_abstract_unix_send_credential(handler->state_socket_pair[1],
 						&(int){state}, sizeof(int));
-	if (ret != sizeof(int))
+	if (ret != sizeof(int)) {
+		if (errno == EINTR)
+			goto again;
 		SYSERROR("Failed to send state to %d",
 			 handler->state_socket_pair[1]);
+		return -1;
+	}
 
 	TRACE("Sent container state \"%s\" to %d", lxc_state2str(state),
 	      handler->state_socket_pair[1]);