+static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
+ vpn_packet_t pkt1, pkt2;
+ vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
+ vpn_packet_t *inpkt = origpkt;
+ int nextpkt = 0;
+ vpn_packet_t *outpkt;
+ int origlen = origpkt->len;
+ size_t outlen;
+#if defined(SOL_IP) && defined(IP_TOS)
+ static int priority = 0;
+#endif
+ int origpriority = origpkt->priority;
+
+ if(!n->status.reachable) {
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+ return;
+ }
+
+ /* Make sure we have a valid key */
+
+ if(!n->status.validkey) {
+ time_t now = time(NULL);
+
+ logger(DEBUG_TRAFFIC, LOG_INFO,
+ "No valid key known yet for %s (%s), forwarding via TCP",
+ n->name, n->hostname);
+
+ if(n->last_req_key + 10 <= now) {
+ send_req_key(n);
+ n->last_req_key = now;
+ }
+
+ send_tcppacket(n->nexthop->connection, origpkt);
+
+ return;
+ }
+
+ if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
+ logger(DEBUG_TRAFFIC, LOG_INFO,
+ "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+ n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
+
+ if(n != n->nexthop)
+ send_packet(n->nexthop, origpkt);
+ else
+ send_tcppacket(n->nexthop->connection, origpkt);
+
+ return;
+ }
+
+ if(experimental && OPTION_VERSION(n->options) >= 2) {
+ uint8_t type = 0;
+ if(!(inpkt->data[12] | inpkt->data[13]))
+ type = PKT_PROBE;
+ sptps_send_record(&n->sptps, type, (char *)inpkt->data, inpkt->len);
+ return;
+ }
+
+ /* Compress the packet */
+
+ if(n->outcompression) {
+ outpkt = pkt[nextpkt++];
+
+ if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)",
+ n->name, n->hostname);
+ return;
+ }
+
+ inpkt = outpkt;
+ }
+
+ /* Add sequence number */
+
+ inpkt->seqno = htonl(++(n->sent_seqno));
+ inpkt->len += sizeof inpkt->seqno;
+
+ /* Encrypt the packet */
+
+ if(cipher_active(&n->outcipher)) {
+ outpkt = pkt[nextpkt++];
+ outlen = MAXSIZE;
+
+ if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
+ goto end;
+ }
+
+ outpkt->len = outlen;
+ inpkt = outpkt;
+ }
+
+ /* Add the message authentication code */
+
+ if(digest_active(&n->outdigest)) {
+ digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
+ inpkt->len += digest_length(&n->outdigest);
+ }
+
+ /* Determine which socket we have to use */
+
+ if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) {
+ for(int sock = 0; sock < listen_sockets; sock++) {
+ if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) {
+ n->sock = sock;
+ break;
+ }
+ }
+ }
+
+ /* Send the packet */
+
+ struct sockaddr *sa;
+ socklen_t sl;
+ int sock;
+
+ /* Overloaded use of priority field: -1 means local broadcast */
+
+ if(origpriority == -1 && n->prevedge) {
+ struct sockaddr_in in;
+ in.sin_family = AF_INET;
+ in.sin_addr.s_addr = -1;
+ in.sin_port = n->prevedge->address.in.sin_port;
+ sa = (struct sockaddr *)∈
+ sl = sizeof in;
+ sock = 0;
+ } else {
+ if(origpriority == -1)
+ origpriority = 0;
+
+ sa = &(n->address.sa);
+ sl = SALEN(n->address.sa);
+ sock = n->sock;
+ }
+
+#if defined(SOL_IP) && defined(IP_TOS)
+ if(priorityinheritance && origpriority != priority
+ && listen_socket[n->sock].sa.sa.sa_family == AF_INET) {
+ priority = origpriority;
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
+ if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
+ logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+ }
+#endif
+
+ if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
+ if(sockmsgsize(sockerrno)) {
+ if(n->maxmtu >= origlen)
+ n->maxmtu = origlen - 1;
+ if(n->mtu >= origlen)
+ n->mtu = origlen - 1;
+ } else
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
+ }
+
+end:
+ origpkt->len = origlen;
+}