Wireshark · Ethereal-dev: [Ethereal-dev] [Patch] for packet-sip.c

[Martin Mathieson <martin.mathieson@xxxxxxxxxxxx>]

Hi,

This patch further tightens up testing for resent packets.
It now always compares the method.  I've seen examples where the called 
party hangs up, and chooses the same CSeq for the BYE as the calling 
party chose for the INVITE.

Regards,
Martin

Index: epan/dissectors/packet-sip.c
===================================================================
--- epan/dissectors/packet-sip.c	(revision 17380)
+++ epan/dissectors/packet-sip.c	(working copy)
@@ -492,6 +492,7 @@
 {
 	guint32 cseq;
 	transaction_state_t transaction_state;
+	gchar method[MAX_CSEQ_METHOD_SIZE];
 	guint32 response_code;
 	gint frame_number;
 } sip_hash_value;
@@ -2095,6 +2096,8 @@
 		p_key->source_port = pinfo->srcport;
 
 		p_val->cseq = cseq_number;
+		strncpy(&p_val->method, cseq_method, MAX_CSEQ_METHOD_SIZE-1);
+		p_val->method[MAX_CSEQ_METHOD_SIZE] = '\0';
 		p_val->transaction_state = nothing_seen;
 		p_val->frame_number = 0;
 
@@ -2109,20 +2112,24 @@
 	/******************************************/
 	/* Is it a resend???                      */
 
-	/* Does this look like a resent request (discount ACK, CANCEL) ? */
+	/* Does this look like a resent request (discount ACK, CANCEL, or a
+	   different method from the original one) ? */
+
 	if ((line_type == REQUEST_LINE) && (cseq_number == cseq_to_compare) &&
-		(p_val->transaction_state == request_seen) &&
-		(strcmp(cseq_method, "ACK") != 0) &&
-		(strcmp(cseq_method, "CANCEL") != 0))
+	    (p_val->transaction_state == request_seen) &&
+	    (strcmp(cseq_method, p_val->method) == 0) &&
+	    (strcmp(cseq_method, "ACK") != 0) &&
+	    (strcmp(cseq_method, "CANCEL") != 0))
 	{
 		result = p_val->frame_number;
 	}
 
 	/* Does this look like a resent final response ? */
 	if ((line_type == STATUS_LINE) && (cseq_number == cseq_to_compare) &&
-		(p_val->transaction_state == final_response_seen) &&
-		(stat_info->response_code >= 200) &&
-		(stat_info->response_code == p_val->response_code))
+	    (p_val->transaction_state == final_response_seen) &&
+	    (strcmp(cseq_method, p_val->method) == 0) &&
+	    (stat_info->response_code >= 200) &&
+	    (stat_info->response_code == p_val->response_code))
 	{
 		result = p_val->frame_number;
 	}