X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=aef55342353cac99096822d10d41c728f34c503e;hp=cf5fb9391ef548c31d4e93c03e02424ecdb1465c;hb=f99661a4ca5bacff47239ce7978b9c9948917c54;hpb=eda71798749e8b0abf5e8b3cbc11da82aa607f00

diff --git a/src/net_packet.c b/src/net_packet.c
index cf5fb939..aef55342 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -2,6 +2,8 @@
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
                   2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2010      Timothy Redaelli <timothy@redaelli.eu>
+                  2010      Brandon Black <blblack@gmail.com>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -59,6 +61,8 @@ static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999
 
 static void send_udppacket(node_t *, vpn_packet_t *);
 
+unsigned replaywin = 16;
+
 #define MAX_SEQNO 1073741824
 
 // mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
@@ -81,16 +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)) {
@@ -144,12 +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;
 	}
 }
 
@@ -292,25 +306,32 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	inpkt->len -= sizeof(inpkt->seqno);
 	inpkt->seqno = ntohl(inpkt->seqno);
 
-	if(inpkt->seqno != n->received_seqno + 1) {
-		if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) {
-			logger(LOG_WARNING, "Lost %d packets from %s (%s)",
-					   inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
-			
-			memset(n->late, 0, sizeof(n->late));
-		} else if (inpkt->seqno <= n->received_seqno) {
-			if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
-				logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
-					   n->name, n->hostname, inpkt->seqno, n->received_seqno);
-				return;
+	if(replaywin) {
+		if(inpkt->seqno != n->received_seqno + 1) {
+			if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
+				if(n->farfuture++ < replaywin >> 2) {
+					logger(LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)",
+						n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture);
+					return;
+				}
+				logger(LOG_WARNING, "Lost %d packets from %s (%s)",
+					   	inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
+				memset(n->late, 0, replaywin);
+			} else if (inpkt->seqno <= n->received_seqno) {
+				if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) {
+					logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
+					   	n->name, n->hostname, inpkt->seqno, n->received_seqno);
+					return;
+				}
+			} else {
+				for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+					n->late[(i / 8) % replaywin] |= 1 << i % 8;
 			}
-		} else {
-			for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
-				n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
 		}
+
+		n->farfuture = 0;
+		n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
 	}
-	
-	n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8);
 
 	if(inpkt->seqno > n->received_seqno)
 		n->received_seqno = inpkt->seqno;