Summary:ASTERISK-22988: [patch]T38 , SIP 488 after Rejecting image media offer due to invalid or unsupported syntax
Reporter:adomjan (adomjan)Labels:
Date Opened:2013-12-13 15:31:07.000-0600Date Closed:2014-01-22 12:31:03.000-0600
Versions: 11.6.0 12.0.0-beta2 Frequency of
duplicatesASTERISK-22262 Asterisk sends SIP 488 to T38 fallback re-invite
Environment:Attachments:( 0) chan_sip.c-decline-rtp_avp-rtp_savp-image-sdp_ignore_null_content.patch
( 1) debug_afterpatch.txt
( 2) debug.txt
Description:adomjan reported an issue that I pulled out of comments on ASTERISK-22262.

[Nov 29 14:50:43] WARNING[32504][C-000000d3] chan_sip.c: Rejecting image media offer due to invalid or unsupported syntax: image 27598 RTP/AVP t38
[Nov 29 14:50:43] VERBOSE[32504][C-000000d3] chan_sip.c:
<--- Reliably Transmitting (no NAT) to --->
SIP/2.0 488 Not acceptable here

the problem is the RTP/AVP and RTP/SAVP, asterisk should decline it from sdp. I couldn't test my patch today I will, next days.

and additionally adomjan reports that his patches works for his case.
Comments:By: Rusty Newton (rnewton) 2013-12-13 15:34:31.881-0600

Can you re-attach your patch to this new issue for tracking sake? (you need to attach it so it will be under your license)


By: adomjan (adomjan) 2013-12-14 14:17:11.853-0600

Sorry for the complication

By: Rusty Newton (rnewton) 2014-01-06 20:44:45.608-0600

No worries. Thanks for the contribution. I've opened the issue open, so it is ready for a developer to review when available.

By: Kinsey Moore (kmoore) 2014-01-21 15:51:51.288-0600

adomjan: Why was it necessary to comment out the code that adds the declination line? It breaks the validity of chan_sip's response SDP.

By: adomjan (adomjan) 2014-01-22 05:46:31.620-0600

I've got in response:


What's happen if the offer->decline_m_line is NULL? I didn't checked the add_content() and the ather called functions, they add something to response string.

so I suggest
if (offer->decline_m_line)
  add_content(resp, offer->decline_m_line);

I have not seen initial value set for offer->decline_m_line it should be also check...

By: Kinsey Moore (kmoore) 2014-01-22 09:40:02.710-0600

This is happening because decline_m_line must be generated when the m-line is parsed. I'll add it to the patch.

By: adomjan (adomjan) 2014-01-22 10:38:48.741-0600

may should add initial value?

AST_LIST_INSERT_TAIL(&p->offered_media, offer, next);
offer->type = SDP_UNKNOWN;
offer->decline_m_line = NULL;

By: Kinsey Moore (kmoore) 2014-01-22 11:43:15.953-0600

ast_calloc automatically initializes the struct to all 0 just like calloc. That won't change the need for the declination line.