[svn-commits] rizzo: branch rizzo/astobj2 r47941 - /team/rizzo/astobj2/channels/chan_sip.c

[svn-commits at lists.digium.com]

Author: rizzo
Date: Wed Nov 22 15:07:22 2006
New Revision: 47941

URL: http://svn.digium.com/view/asterisk?view=rev&rev=47941
Log:
use 0xffffffff instead of 0 as a marker for 'uninitialized' icseq,
as 0 is a legal cseq value.


Modified:
    team/rizzo/astobj2/channels/chan_sip.c

Modified: team/rizzo/astobj2/channels/chan_sip.c
URL: http://svn.digium.com/view/asterisk/team/rizzo/astobj2/channels/chan_sip.c?view=diff&rev=47941&r1=47940&r2=47941
==============================================================================
--- team/rizzo/astobj2/channels/chan_sip.c (original)
+++ team/rizzo/astobj2/channels/chan_sip.c Wed Nov 22 15:07:22 2006
@@ -208,6 +208,7 @@
 #define SIP_MAX_PACKET               4096             /*!< Also from RFC 3261 (2543), should sub headers tho */
 
 #define INITIAL_CSEQ                 101              /*!< our initial sip sequence number */
+#define UNINITIALIZED_ICSEQ	     ((unsigned int)0xffffffff)	/*!< marker for not-initialized ICSEQ */
 
 /*! \brief Global jitterbuffer configuration - by default, jb is disabled */
 static struct ast_jb_conf default_jbconf =
@@ -4499,6 +4500,7 @@
 	p->branch = ast_random();	
 	make_our_tag(p->tag, sizeof(p->tag));
 	p->ocseq = INITIAL_CSEQ;
+	p->icseq = UNINITIALIZED_ICSEQ;	/* not initialized - any incoming value is good */
 
 	if (sip_methods[intended_method].need_rtp) {
 		p->rtp = ast_rtp_new_with_bindaddr(sched, io, 1, 0, bindaddr.sin_addr);
@@ -15043,29 +15045,30 @@
 	if (option_debug > 3)
 		ast_log(LOG_DEBUG, "**** Received %s (%d) - Command in SIP %s\n", sip_methods[p->method].text, sip_methods[p->method].id, req->rlPart1); 
 
-	if (p->icseq && (p->icseq > seqno)) {
+	if (p->icseq == UNINITIALIZED_ICSEQ) {	/* not initialized - anything is good */
+		p->icseq = seqno;
+	} else if (seqno < p->icseq) {	/* old packet */
 		if (option_debug)
 			ast_log(LOG_DEBUG, "Ignoring too old SIP packet packet %d (expecting >= %d)\n", seqno, p->icseq);
 		if (req->method != SIP_ACK)
 			transmit_response(p, "503 Server error", req);	/* We must respond according to RFC 3261 sec 12.2 */
 		return -1;
-	} else if (p->icseq &&
-		   p->icseq == seqno &&
-		   req->method != SIP_ACK &&
+	} else if (p->icseq == seqno && req->method != SIP_ACK &&
 		   (p->method != SIP_CANCEL || ast_test_flag(&p->flags[0], SIP_ALREADYGONE))) {
-		/* ignore means "don't do anything with it" but still have to 
-		   respond appropriately.  We do this if we receive a repeat of
-		   the last sequence number  */
+		/* Duplicate of the last sequence. Set the SIP_PKT_IGNORE flag, meaning
+		 * "don't do anything with it" (because we have already performed the
+		 * required action), but still have to respond appropriately, as the other
+		 * side might have lost our message.
+		 */
 		ast_set_flag(req, SIP_PKT_IGNORE);
 		if (option_debug > 2)
 			ast_log(LOG_DEBUG, "Ignoring SIP message because of retransmit (%s Seqno %d, ours %d)\n", sip_methods[p->method].text, p->icseq, seqno);
-	}
-		
-	if (seqno >= p->icseq)
-		/* Next should follow monotonically (but not necessarily 
-		   incrementally -- thanks again to the genius authors of SIP --
-		   increasing */
+	} else {
+		/* Good sequence number - record it. It can be anything larger than the
+		 * previous sequence number, not necessarily incremented by 1.
+		 */
 		p->icseq = seqno;
+	}
 
 	/* Find their tag if we haven't got it */
 	if (ast_strlen_zero(p->theirtag)) {