Send large packets we cannot handle properly via TCP.

[tinc] / src / net_packet.c

diff --git a/src/net_packet.c b/src/net_packet.c
index 0126d41..aca8468 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -70,6 +70,11 @@ void send_mtu_probe(node_t *n)
        n->mtuprobes++;
        n->mtuevent = NULL;
 
+       if(!n->status.reachable) {
+               logger(LOG_DEBUG, _("Trying to send MTU probe to unreachable node %s (%s)"), n->name, n->hostname);
+               return;
+       }
+
        if(n->mtuprobes >= 10 && !n->minmtu) {
                ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
                return;
@@ -82,7 +87,7 @@ void send_mtu_probe(node_t *n)
                        return;
                }
 
-               len = n->minmtu + 1 + random() % (n->maxmtu - n->minmtu);
+               len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
                if(len < 64)
                        len = 64;
                
@@ -103,15 +108,15 @@ void send_mtu_probe(node_t *n)
        event_add(n->mtuevent);
 }
 
-void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
+void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
        ifdebug(TRAFFIC) logger(LOG_INFO, _("Got MTU probe length %d from %s (%s)"), packet->len, n->name, n->hostname);
 
        if(!packet->data[0]) {
                packet->data[0] = 1;
                send_packet(n, packet);
        } else {
-               if(n->minmtu < packet->len)
-                       n->minmtu = packet->len;
+               if(n->minmtu < len)
+                       n->minmtu = len;
        }
 }
 
@@ -270,6 +275,8 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
 
        /* Decompress the packet */
 
+       length_t origlen = inpkt->len;
+
        if(n->incompression) {
                outpkt = pkt[nextpkt++];
 
@@ -280,6 +287,8 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
                }
 
                inpkt = outpkt;
+
+               origlen -= MTU/64 + 20;
        }
 
        inpkt->priority = 0;
@@ -288,7 +297,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
                n->connection->last_ping_time = now;
 
        if(!inpkt->data[12] && !inpkt->data[13])
-               mtu_probe_h(n, inpkt);
+               mtu_probe_h(n, inpkt, origlen);
        else
                receive_packet(n, inpkt);
 }
@@ -324,6 +333,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
 
        cp();
 
+       if(!n->status.reachable) {
+               ifdebug(TRAFFIC) logger(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) {
@@ -341,9 +355,9 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
                return;
        }
 
-       if(n->options & OPTION_PMTU_DISCOVERY && !n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
+       if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
                ifdebug(TRAFFIC) logger(LOG_INFO,
-                               _("No minimum MTU established yet for %s (%s), forwarding via TCP"),
+                               _("Packet for %s (%s) larger than minimum MTU, forwarding via TCP"),
                                n->name, n->hostname);
 
                send_tcppacket(n->nexthop->connection, origpkt);
@@ -484,9 +498,15 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet)
        ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
                           packet->len, from->name, from->hostname);
 
-       if(from != myself)
+       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)
+                       return;
+       }
+
        for(node = connection_tree->head; node; node = node->next) {
                c = node->data;
 
@@ -532,7 +552,8 @@ void handle_incoming_vpn_data(int sock)
        pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
        if(pkt.len < 0) {
-               logger(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno));
+               if(errno != EAGAIN && errno != EINTR)
+                       logger(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno));
                return;
        }