#define MAX_SEQNO 1073741824
+// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
+// mtuprobes == 31: sleep pinginterval seconds
+// mtuprobes == 32: send 1 burst, sleep pingtimeout second
+// mtuprobes == 33: no response from other side, restart PMTU discovery process
+
void send_mtu_probe(node_t *n) {
vpn_packet_t packet;
int len, i;
+ int timeout = 1;
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);
+ if(!n->status.reachable || !n->status.validkey) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
+ n->mtuprobes = 0;
return;
}
+ if(n->mtuprobes > 32) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ n->mtuprobes = 1;
+ n->minmtu = 0;
+ n->maxmtu = MTU;
+ }
+
if(n->mtuprobes >= 10 && !n->minmtu) {
ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+ n->mtuprobes = 0;
return;
}
+ if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
+ if(n->minmtu > n->maxmtu)
+ n->minmtu = n->maxmtu;
+ else
+ n->maxmtu = n->minmtu;
+ n->mtu = n->minmtu;
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
+ n->mtuprobes = 31;
+ }
+
+ if(n->mtuprobes == 31) {
+ timeout = pinginterval;
+ goto end;
+ } else if(n->mtuprobes == 32) {
+ timeout = pingtimeout;
+ }
+
for(i = 0; i < 3; i++) {
- if(n->mtuprobes >= 30 || n->minmtu >= n->maxmtu) {
- n->mtu = n->minmtu;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
- return;
- }
+ if(n->maxmtu <= n->minmtu)
+ len = n->maxmtu;
+ else
+ len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
- len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
if(len < 64)
len = 64;
send_udppacket(n, &packet);
}
+end:
n->mtuevent = new_event();
n->mtuevent->handler = (event_handler_t)send_mtu_probe;
n->mtuevent->data = n;
- n->mtuevent->time = now + 1;
+ n->mtuevent->time = now + timeout;
event_add(n->mtuevent);
}
if(!packet->data[0]) {
packet->data[0] = 1;
- send_packet(n, packet);
+ send_udppacket(n, packet);
} else {
+ if(len > n->maxmtu)
+ len = n->maxmtu;
if(n->minmtu < len)
n->minmtu = len;
+ if(n->mtuprobes > 30)
+ n->mtuprobes = 30;
}
}
inpkt->priority = 0;
- if(n->connection)
- n->connection->last_ping_time = now;
-
if(!inpkt->data[12] && !inpkt->data[13])
mtu_probe_h(n, inpkt, origlen);
else
if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
ifdebug(TRAFFIC) logger(LOG_INFO,
- "Packet for %s (%s) larger than minimum MTU, forwarding via TCP",
- n->name, n->hostname);
+ "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+ n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
- send_tcppacket(n->nexthop->connection, origpkt);
+ if(n != n->nexthop)
+ send_packet(n->nexthop, origpkt);
+ else
+ send_tcppacket(n->nexthop->connection, origpkt);
return;
}
avl_node_t *node;
edge_t *e;
node_t *n = NULL;
+ static time_t last_hard_try = 0;
for(node = edge_weight_tree->head; node; node = node->next) {
e = node->data;
- if(sockaddrcmp_noport(from, &e->address))
- continue;
+ if(sockaddrcmp_noport(from, &e->address)) {
+ if(last_hard_try == now)
+ continue;
+ last_hard_try = now;
+ }
if(!n)
n = e->to;