From: Guus Sliepen <guus@tinc-vpn.org>
Date: Fri, 18 Apr 2003 21:18:36 +0000 (+0000)
Subject: Better handling of late packets.
X-Git-Tag: import-tinc-1.1~785^2~194
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=bc9e78250ef6fb5169d03565b7d8d9caf309eb98;p=meshlink

Better handling of late packets.
---

diff --git a/src/net_packet.c b/src/net_packet.c
index 07f578e5..724eaa33 100644
--- 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 1.1.2.26 2003/03/28 13:41:49 guus Exp $
+    $Id: net_packet.c,v 1.1.2.27 2003/04/18 21:18:36 guus Exp $
 */
 
 #include "config.h"
@@ -95,6 +95,7 @@ void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
 	int outlen, outpad;
 	long int complen = MTU + 12;
 	char hmac[EVP_MAX_MD_SIZE];
+	int i;
 
 	cp();
 
@@ -133,16 +134,26 @@ 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) {
-		if(debug_lvl >= DEBUG_TRAFFIC)
-			syslog(LOG_DEBUG,
-				   _("Got late or replayed packet from %s (%s), seqno %d"),
-				   n->name, n->hostname, inpkt->seqno);
-		return;
+	if(inpkt->seqno != n->received_seqno + 1) {
+		if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) {
+			if(debug_lvl >= DEBUG_TRAFFIC)
+				syslog(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(inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8 || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
+				syslog(LOG_WARNING, _("Got late or replayed packet from %s (%s), seqno %d, last received %d"),
+					   n->name, n->hostname, inpkt->seqno, n->received_seqno, n->late[(inpkt->seqno / 8) % sizeof(n->late)]);
+			} else
+				for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+					n->late[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8;
+		}
 	}
-
+	
 	n->received_seqno = inpkt->seqno;
-
+	n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_seqno % 8);
+			
 	if(n->received_seqno > MAX_SEQNO)
 		keyexpires = 0;
 
diff --git a/src/node.h b/src/node.h
index e4dcd524..6e5e68eb 100644
--- a/src/node.h
+++ b/src/node.h
@@ -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: node.h,v 1.1.2.20 2002/09/09 21:24:41 guus Exp $
+    $Id: node.h,v 1.1.2.21 2003/04/18 21:18:36 guus Exp $
 */
 
 #ifndef __TINC_NODE_H__
@@ -73,6 +73,7 @@ typedef struct node_t {
 
 	uint32_t sent_seqno;		/* Sequence number last sent to this node */
 	uint32_t received_seqno;	/* Sequence number last received from this node */
+	unsigned char late[16];	/* Bitfield marking late packets */
 } node_t;
 
 extern struct node_t *myself;
diff --git a/src/protocol_key.c b/src/protocol_key.c
index 2453975d..786a8a17 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.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: protocol_key.c,v 1.1.4.14 2002/09/09 22:33:03 guus Exp $
+    $Id: protocol_key.c,v 1.1.4.15 2003/04/18 21:18:36 guus Exp $
 */
 
 #include "config.h"
@@ -135,6 +135,7 @@ int req_key_h(connection_t *c)
 	if(to == myself) {			/* Yes, send our own key back */
 		mykeyused = 1;
 		from->received_seqno = 0;
+		memset(from->late, 0, sizeof(from->late));
 		send_ans_key(c, myself, from);
 	} else {
 		send_req_key(to->nexthop->connection, from, to);