diff options
| -rw-r--r-- | channels/chan_sip.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/channels/chan_sip.c b/channels/chan_sip.c index 79034409d..2a92735bb 100644 --- a/channels/chan_sip.c +++ b/channels/chan_sip.c @@ -19256,17 +19256,18 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int } if (!req->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. + if (!ast_test_flag(&p->flags[0], SIP_OUTGOING) && (p->invitestate == INV_COMPLETED || p->invitestate == INV_TERMINATED)) { + /* What do these circumstances mean? We have received an INVITE for an "incoming" dialog for which we + * have sent a final response. We have not yet received an ACK, though (which is why p->pendinginvite is non-zero). + * We also know that the INVITE is not a retransmission, because otherwise the "ignore" flag would be set. + * This means that either we are receiving a reinvite for a terminated dialog, or we are receiving an INVITE with + * credentials based on one we challenged earlier. + * + * The action to take in either case is to treat the INVITE as though it contains an implicit ACK for the previous + * transaction. Calling __sip_ack will take care of this by clearing the p->pendinginvite and removing the response + * from the previous transaction from the list of outstanding packets. */ - __sip_ack(p, p->lastinvite, 1, 0); + __sip_ack(p, p->pendinginvite, 1, 0); } else { /* We already have a pending invite. Sorry. You are on hold. */ p->glareinvite = seqno; /* must hold on to this seqno to process ack and retransmit correctly */ |