More sensible name, and try to set PMTU discovery on IPv6 sockets as well.

[oweals/tinc.git] / src / net_packet.c

diff --git a/src/net_packet.c b/src/net_packet.c
index af34d0598d54b2d9706e6bff228e0a5c09910157..d2e9aa816c846a589fa575d1bf996a238b8b0623 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net_packet.c,v 1.1.2.44 2003/12/12 19:52:25 guus Exp $
+    $Id: net_packet.c,v 1.1.2.46 2003/12/20 21:09:33 guus Exp $
 */
 
 #include "system.h"
@@ -52,9 +52,63 @@ int keyexpires = 0;
 EVP_CIPHER_CTX packet_ctx;
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
 
+static void send_udppacket(node_t *, vpn_packet_t *);
 
 #define MAX_SEQNO 1073741824
 
+void send_mtu_probe(node_t *n)
+{
+       vpn_packet_t packet;
+       int len, i;
+       
+       cp();
+
+       n->mtuprobes++;
+
+       if(n->mtuprobes >= 10 && !n->probedmtu) {
+               ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
+               return;
+       }
+
+       for(i = 0; i < 3; i++) {
+               if(n->mtuprobes >= 30 || n->probedmtu >= n->mtu) {
+                       n->mtu = n->probedmtu;
+                       ifdebug(TRAFFIC) logger(LOG_INFO, _("Fixing MTU of %s (%s) to %d after %d probes"), n->name, n->hostname, n->mtu, n->mtuprobes);
+                       return;
+               }
+
+               len = n->probedmtu + 1 + random() % (n->mtu - n->probedmtu);
+               if(len < 64)
+                       len = 64;
+               
+               memset(packet.data, 0, 14);
+               RAND_pseudo_bytes(packet.data + 14, len - 14);
+               packet.len = len;
+
+               ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
+
+               send_udppacket(n, &packet);
+       }
+
+       n->mtuevent = xmalloc(sizeof(*n->mtuevent));
+       n->mtuevent->handler = (event_handler_t)send_mtu_probe;
+       n->mtuevent->data = n;
+       n->mtuevent->time = now + 1;
+       event_add(n->mtuevent);
+}
+
+void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
+       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->probedmtu < packet->len)
+                       n->probedmtu = packet->len;
+       }
+}
+
 static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level)
 {
        if(level == 10) {
@@ -203,7 +257,10 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
        if(n->connection)
                n->connection->last_ping_time = now;
 
-       receive_packet(n, inpkt);
+       if(!inpkt->data[12] && !inpkt->data[13])
+               mtu_probe_h(n, inpkt);
+       else
+               receive_packet(n, inpkt);
 }
 
 void receive_tcppacket(connection_t *c, char *buffer, int len)
@@ -328,6 +385,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
 
        if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
                logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
+               if(errno == EMSGSIZE) {
+                       if(n->mtu >= origlen)
+                               n->mtu = origlen - 1;
+               }
                return;
        }