Use datagram SPTPS for packet exchange between nodes.
[tinc] / src / net_packet.c
index ac3b0cc..4e65155 100644 (file)
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
                   2010      Timothy Redaelli <timothy@redaelli.eu>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -265,6 +265,11 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        vpn_packet_t *outpkt = pkt[0];
        size_t outlen;
 
+       if(experimental && OPTION_VERSION(n->options) >= 2) {
+               sptps_receive_data(&n->sptps, (char *)inpkt->data - 4, inpkt->len);
+               return;
+       }
+
        if(!cipher_active(&n->incipher)) {
                logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
                                        n->name, n->hostname);
@@ -390,8 +395,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        size_t outlen;
 #if defined(SOL_IP) && defined(IP_TOS)
        static int priority = 0;
-       int origpriority = origpkt->priority;
 #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);
@@ -430,6 +435,14 @@ static void send_udppacket(node_t *n, vpn_packet_t *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) {
@@ -531,6 +544,75 @@ end:
        origpkt->len = origlen;
 }
 
+bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
+       node_t *to = handle;
+
+       if(type >= SPTPS_HANDSHAKE) {
+               char buf[len * 4 / 3 + 5];
+               b64encode(data, buf, len);
+               if(!to->status.validkey)
+                       return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 -1", ANS_KEY, myself->name, to->name, buf);
+               else
+                       return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_SPTPS, buf);
+       }
+
+       /* Send the packet */
+
+       struct sockaddr *sa;
+       socklen_t sl;
+       int sock;
+
+       sa = &(to->address.sa);
+       sl = SALEN(to->address.sa);
+       sock = to->sock;
+
+       if(sendto(listen_socket[sock].udp, data, len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
+               if(sockmsgsize(sockerrno)) {
+                       if(to->maxmtu >= len)
+                               to->maxmtu = len - 1;
+                       if(to->mtu >= len)
+                               to->mtu = len - 1;
+               } else {
+                       logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", to->name, to->hostname, sockstrerror(sockerrno));
+                       return false;
+               }
+       }
+
+       return true;
+}
+
+bool receive_sptps_record(void *handle, uint8_t type, const char *data, uint16_t len) {
+       node_t *from = handle;
+
+       if(type == SPTPS_HANDSHAKE) {
+               from->status.validkey = true;
+               logger(DEBUG_META, LOG_INFO, "SPTPS key exchange with %s (%s) succesful", from->name, from->hostname);
+               return true;
+       }
+
+       if(len > MTU) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Packet from %s (%s) larger than maximum supported size (%d > %d)", from->name, from->hostname, len, MTU);
+               return false;
+       }
+
+       vpn_packet_t inpkt;
+       inpkt.len = len;
+       memcpy(inpkt.data, data, len);
+
+       if(type == PKT_PROBE) {
+               mtu_probe_h(from, &inpkt, len);
+               return true;
+
+       }
+       if(type != 0) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Unexpected SPTPS record type %d len %d from %s (%s)", type, len, from->name, from->hostname);
+               return false;
+       }
+
+       receive_packet(from, &inpkt);
+       return true;
+}
+
 /*
   send a packet to the given vpn ip.
 */
@@ -576,24 +658,50 @@ void send_packet(node_t *n, vpn_packet_t *packet) {
 void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
        splay_node_t *node;
        connection_t *c;
+       node_t *n;
+
+       // Always give ourself a copy of the packet.
+       if(from != myself)
+               send_packet(myself, packet);
+
+       // In TunnelServer mode, do not forward broadcast packets.
+        // The MST might not be valid and create loops.
+       if(tunnelserver || broadcast_mode == BMODE_NONE)
+               return;
 
        logger(DEBUG_TRAFFIC, LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
                           packet->len, from->name, from->hostname);
 
-       if(from != myself) {
-               send_packet(myself, packet);
+       switch(broadcast_mode) {
+               // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
+               // This guarantees all nodes receive the broadcast packet, and
+               // usually distributes the sending of broadcast packets over all nodes.
+               case BMODE_MST:
+                       for(node = connection_tree->head; node; node = node->next) {
+                               c = node->data;
 
-               // In TunnelServer mode, do not forward broadcast packets.
-                // The MST might not be valid and create loops.
-               if(tunnelserver)
-                       return;
-       }
+                               if(c->status.active && c->status.mst && c != from->nexthop->connection)
+                                       send_packet(c->node, packet);
+                       }
+                       break;
+
+               // In direct mode, we send copies to each node we know of.
+               // However, this only reaches nodes that can be reached in a single hop.
+               // We don't have enough information to forward broadcast packets in this case.
+               case BMODE_DIRECT:
+                       if(from != myself)
+                               break;
+
+                       for(node = node_udp_tree->head; node; node = node->next) {
+                               n = node->data;
 
-       for(node = connection_tree->head; node; node = node->next) {
-               c = node->data;
+                               if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+                                       send_packet(n, packet);
+                       }
+                       break;
 
-               if(c->status.active && c->status.mst && c != from->nexthop->connection)
-                       send_packet(c->node, packet);
+               default:
+                       break;
        }
 }