+static int client_receive_message_udp(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ _cleanup_free_ DHCPMessage *message = NULL;
+ int buflen = 0, len, r;
+ usec_t time_now;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ r = ioctl(fd, FIONREAD, &buflen);
+ if (r < 0 || buflen <= 0)
+ buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
+
+ message = malloc0(buflen);
+ if (!message)
+ return -ENOMEM;
+
+ len = read(fd, message, buflen);
+ if (len < 0)
+ return 0;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, message, len,
+ time_now);
+}
+
+static int client_receive_message_raw(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ _cleanup_free_ DHCPPacket *packet = NULL;
+ int buflen = 0, len, r;
+ usec_t time_now;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ r = ioctl(fd, FIONREAD, &buflen);
+ if (r < 0 || buflen <= 0)
+ buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
+
+ packet = malloc0(buflen);
+ if (!packet)
+ return -ENOMEM;
+
+ len = read(fd, packet, buflen);
+ if (len < 0)
+ return 0;
+
+ r = dhcp_packet_verify_headers(packet, len);
+ if (r < 0)
+ return 0;
+
+ len -= DHCP_IP_UDP_SIZE;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, &packet->dhcp, len, time_now);
+}
+