diff options
author | Mark Michelson <mmichelson@digium.com> | 2012-06-06 19:25:44 +0000 |
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committer | Mark Michelson <mmichelson@digium.com> | 2012-06-06 19:25:44 +0000 |
commit | ea8cf8b5f3d186ea7f8e120f2f812a565775ed7e (patch) | |
tree | 0fc7edc48ab2807d67bffa7f3760e20290ab37dc | |
parent | d197f69107d1a38adb92290a54e038c0820d0802 (diff) |
Fix a specific scenario where ACKs are not matched.
If a dialog-starting INVITE contains a to-tag, then Asterisk
will respond with a 481. In this case, the resulting incoming
ACK would not be matched, so Asterisk would continue retransmitting
the 481 until the transaction times out.
There were two issues. Asterisk, upon creating a sip_pvt would generate
a local tag. However, when the time came to transmit the 481, since there
was a to-tag in the INVITE, Asterisk would place this original to-tag
in the 481 response. When the ACK came in, Asterisk would attempt to
match the to-tag in the ACK to the generated local tag. Unfortunately,
Asterisk never actually transmitted a response with the generated local
tag, so the to-tag in the ACK would not match.
The other problem was that when the 481 was sent, nothing was set
on the sip_pvt to indicate what CSeq is expected in the ACK.
To fix the first problem, we zero out the to-tag seen in the incoming
INVITE. This way, Asterisk, when time to send a response, will send
its generated local tag instead.
To fix the second problem, we set the sip_pvt's pendinginvite to the
CSeq of the INVITE when we send a 481.
(closes issue ASTERISK-19892)
Reported by Mark Michelson
........
Merged revisions 368625 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........
Merged revisions 368629 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@368637 65c4cc65-6c06-0410-ace0-fbb531ad65f3
-rw-r--r-- | channels/chan_sip.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/channels/chan_sip.c b/channels/chan_sip.c index 5b1d252be..051a538ec 100644 --- a/channels/chan_sip.c +++ b/channels/chan_sip.c @@ -26468,6 +26468,15 @@ static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct as if (!p->initreq.headers && req->has_to_tag) { /* If this is a first request and it got a to-tag, it is not for us */ if (!req->ignore && req->method == SIP_INVITE) { + /* We will be subversive here. By blanking out the to-tag of the request, + * it will cause us to attach our own generated to-tag instead. This way, + * when we receive an ACK, the ACK will contain the to-tag we generated, + * resulting in a proper to-tag match. + */ + char *to_header = (char *) sip_get_header(req, "To"); + char *tag = strstr(to_header, ";tag="); + *tag = '\0'; + p->pendinginvite = p->icseq; transmit_response_reliable(p, "481 Call/Transaction Does Not Exist", req); /* Will cease to exist after ACK */ return res; |