+ if (group)
+ *_group = group;
+
+ return r;
+}
+
+/* On success, the number of bytes received is returned and *ret points to the received message
+ * which has a valid header and the correct size.
+ * If nothing useful was received 0 is returned.
+ * On failure, a negative error code is returned.
+ */
+int socket_read_message(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *first = NULL;
+ struct iovec iov = {};
+ uint32_t group = 0;
+ bool multi_part = false, done = false;
+ struct nlmsghdr *new_msg;
+ size_t len;
+ int r;
+ unsigned i = 0;
+
+ assert(rtnl);
+ assert(rtnl->rbuffer);
+ assert(rtnl->rbuffer_allocated >= sizeof(struct nlmsghdr));
+
+ /* read nothing, just get the pending message size */
+ r = socket_recv_message(rtnl->fd, &iov, &group, true);
+ if (r <= 0)
+ return r;
+ else
+ len = (size_t)r;
+
+ /* make room for the pending message */
+ if (!greedy_realloc((void **)&rtnl->rbuffer,
+ &rtnl->rbuffer_allocated,
+ len, sizeof(uint8_t)))
+ return -ENOMEM;
+
+ iov.iov_base = rtnl->rbuffer;
+ iov.iov_len = rtnl->rbuffer_allocated;
+
+ /* read the pending message */
+ r = socket_recv_message(rtnl->fd, &iov, &group, false);
+ if (r <= 0)
+ return r;
+ else
+ len = (size_t)r;
+
+ if (len > rtnl->rbuffer_allocated)
+ /* message did not fit in read buffer */
+ return -EIO;
+
+ if (NLMSG_OK(rtnl->rbuffer, len) && rtnl->rbuffer->nlmsg_flags & NLM_F_MULTI) {
+ multi_part = true;
+
+ for (i = 0; i < rtnl->rqueue_partial_size; i++) {
+ if (rtnl_message_get_serial(rtnl->rqueue_partial[i]) ==
+ rtnl->rbuffer->nlmsg_seq) {
+ first = rtnl->rqueue_partial[i];
+ break;
+ }
+ }
+ }
+
+ for (new_msg = rtnl->rbuffer; NLMSG_OK(new_msg, len); new_msg = NLMSG_NEXT(new_msg, len)) {