From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sun, 2 Jan 2011 14:02:23 +0000 (+0100)
Subject: Always send MTU probes at least once every PingInterval.
X-Git-Tag: release-1.0.14~22
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=f99661a4ca5bacff47239ce7978b9c9948917c54;hp=cac0a5c651535e8317839b0deff1ee98086a8184

Always send MTU probes at least once every PingInterval.

Before, if MTU probes failed, tinc would stop sending probes until the next
time keys were regenerated (by default, once every hour).  Now it continues to
send them every PingInterval, so it recovers faster from temporary failures.
---

diff --git a/src/net_packet.c b/src/net_packet.c
index 9e5ef465..aef55342 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -85,16 +85,21 @@ void send_mtu_probe(node_t *n) {
 	}
 
 	if(n->mtuprobes > 32) {
+		if(!n->minmtu) {
+			n->mtuprobes = 31;
+			timeout = pinginterval;
+			goto end;
+		}
+
 		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) {
+	if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
-		n->mtuprobes = 0;
-		return;
+		n->mtuprobes = 31;
 	}
 
 	if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
@@ -148,12 +153,17 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 		packet->data[0] = 1;
 		send_udppacket(n, packet);
 	} else {
+		if(n->mtuprobes > 30) {
+			if(n->minmtu)
+				n->mtuprobes = 30;
+			else
+				n->mtuprobes = 1;
+		}
+
 		if(len > n->maxmtu)
 			len = n->maxmtu;
 		if(n->minmtu < len)
 			n->minmtu = len;
-		if(n->mtuprobes > 30)
-			n->mtuprobes = 30;
 	}
 }
 
diff --git a/src/protocol_key.c b/src/protocol_key.c
index fbd7cabb..e2e4be5d 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -310,7 +310,7 @@ bool ans_key_h(connection_t *c) {
 		update_node_udp(from, &sa);
 	}
 
-	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes)
+	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuevent)
 		send_mtu_probe(from);
 
 	return true;