"CMP_ADDRESS()" is not guaranteed to return 0, 1, or -1, it's just

guaranteed to return 0, a positive number, or a negative number, based
on the result of the comparison.  Furthermore, if it returns 0, meaning
the source and destination addresses are the same, we have to look at
the port numbers to decide which side of the conversation the frame is
from.

svn path=/trunk/; revision=6064

1 files changed, 35 insertions, 6 deletions

diff --git a/packet-tcp.c b/packet-tcp.c
index edce587216..bb454adab3 100644
--- a/packet-tcp.c
+++ b/packet-tcp.c
@@ -1,7 +1,7 @@
 /* packet-tcp.c
  * Routines for TCP packet disassembly
  *
- * $Id: packet-tcp.c,v 1.154 2002/08/21 23:57:38 sahlberg Exp $
+ * $Id: packet-tcp.c,v 1.155 2002/08/22 19:40:03 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -164,9 +164,18 @@ static GHashTable *tcp_rel_seq_table = NULL;
 static GMemChunk *tcp_analysis_chunk = NULL;
 static int tcp_analysis_count = 20;	/* one for each conversation */
 struct tcp_analysis {
-	/* these two structs are managed such as CMP_ADDRESS(src,dst)
-	 * ==1,  then stuff sent from src is in ual1
-	 * ==-1, then stuff sent from src is in ual2 and vv
+	/* These two structs are managed based on comparing the source
+	 * and destination addresses and, if they're equal, comparing
+	 * the source and destination ports.
+	 *
+	 * If the source is greater than the destination, then stuff
+	 * sent from src is in ual1.
+	 *
+	 * If the source is less than the destination, then stuff
+	 * sent from src is in ual2.
+	 *
+	 * XXX - if the addresses and ports are equal, we don't guarantee
+	 * the behavior.
 	 */
 	struct tcp_unacked *ual1;	/* UnAcked List 1*/
 	guint32 base_seq1;
@@ -237,7 +246,18 @@ tcp_analyze_sequence_number(packet_info *pinfo, guint32 seq, guint32 ack, guint3
 
 	/* check direction and get ua lists */
 	direction=CMP_ADDRESS(&pinfo->src, &pinfo->dst);
-	if(direction==1){
+	if(direction==0)
+		direction=pinfo->srcport - pinfo->destport;
+	if(direction>=0){
+		/*
+		 * XXX - if direction == 0, that'll be true for packets
+		 * from both sides of the connection, so this won't
+		 * work.
+		 *
+		 * That'd be a connection from a given port on a machine
+		 * to that same port on the same machine; does that ever
+		 * happen?
+		 */
 		ual1=tcpd->ual1;
 		ual2=tcpd->ual2;
 		base_seq=tcpd->base_seq1;
@@ -478,7 +498,16 @@ ack_finished:
 
 
 	/* store the lists back in our struct */
-	if(direction==1){
+	if(direction>=0){
+		/*
+		 * XXX - if direction == 0, that'll be true for packets
+		 * from both sides of the connection, so this won't
+		 * work.
+		 *
+		 * That'd be a connection from a given port on a machine
+		 * to that same port on the same machine; does that ever
+		 * happen?
+		 */
 		tcpd->ual1=ual1;
 		tcpd->ual2=ual2;
 		tcpd->base_seq1=base_seq;