Handle a SIP race condition (reinvite before an ACK) properly.

RFC 5047 explains the proper course of action to take if a 
reINVITE is received before the ACK from a previous invite
transaction. What we are to do is to treat the reINVITE as
if it were both an ACK and a reINVITE and process it normally.

Later, when we receive the ACK we had been expecting, we will
ignore it since its CSeq is less than the current iseqno of
the sip_pvt representing this dialog.

(closes issue #13849)
Reported by: klaus3000
Patches:
      13849_v2.patch uploaded by mmichelson (license 60)
Tested by: mmichelson, klaus3000



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@187484 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Mark Michelson
2009-04-09 18:51:20 +00:00
parent 200db93157
commit a4e46eb871

View File

@@ -14435,6 +14435,18 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
}
if (!ast_test_flag(req, SIP_PKT_IGNORE) && p->pendinginvite) {
if (!ast_test_flag(&p->flags[0], SIP_OUTGOING) && ast_test_flag(&p->flags[1], SIP_PAGE2_DIALOG_ESTABLISHED)) {
/* We have received a reINVITE on an incoming call to which we have sent a 200 OK but not yet received
* an ACK. According to RFC 5407, Section 3.1.4, the proper way to handle this race condition is to accept
* the reINVITE since we have established a dialog.
*/
/* Note that this will both clear the pendinginvite flag and cancel the
* retransmission of the 200 OK. Basically, we're accepting this reINVITE as both an ACK
* and a reINVITE in one request.
*/
__sip_ack(p, p->lastinvite, FLAG_RESPONSE, 0);
} else {
/* We already have a pending invite. Sorry. You are on hold. */
p->glareinvite = seqno;
transmit_response_reliable(p, "491 Request Pending", req);
@@ -14443,6 +14455,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
/* Don't destroy dialog here */
return 0;
}
}
p_replaces = get_header(req, "Replaces");
if (!ast_strlen_zero(p_replaces)) {