Fix problem where a hung channel could occur on a failed blind transfer.

Different clients react differently to being told that a blind transfer
has failed. Some will simply send a BYE and be done with it. Others will
attempt to reinvite themselves back onto the call.

In the latter case, we were creating a new channel and then leaving it to
sit forever doing nothing. With this code change, that new channel will
not be created and the dialog with the transferring channel will be cleaned
up properly.

ASTERISK-24624 #close
Reported by Zane Conkle

Review: https://reviewboard.asterisk.org/r/4339
........

Merged revisions 430714 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@430715 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 15 insertions, 0 deletions

diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index cad0a7c5f..06828ac60 100644
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -2063,6 +2063,21 @@ static int chan_pjsip_incoming_request(struct ast_sip_session *session, struct p
 		return 0;
 	}
 
+	if (session->inv_session->state >= PJSIP_INV_STATE_CONFIRMED) {
+		/* Weird case. We've received a reinvite but we don't have a channel. The most
+		 * typical case for this happening is that a blind transfer fails, and so the
+		 * transferer attempts to reinvite himself back into the call. We already got
+		 * rid of that channel, and the other side of the call is unrecoverable.
+		 *
+		 * We treat this as a failure, so our best bet is to just hang this call
+		 * up and not create a new channel. Clearing defer_terminate here ensures that
+		 * calling ast_sip_session_terminate() can result in a BYE being sent ASAP.
+		 */
+		session->defer_terminate = 0;
+		ast_sip_session_terminate(session, 400);
+		return -1;
+	}
+
 	datastore = ast_sip_session_alloc_datastore(&transport_info, "transport_info");
 	if (!datastore) {
 		return -1;