[Linphone-developers] [PATCH] small fixes to SDP handling in coreapi

[Martin Hörlin]

Hello,
I have made a small patch that makes Linphone more compliant with "RFC 
3264 - An Offer/Answer Model with Session Description Protocol" and RFC 
2327 SDP.

Problem description:
1. Linphone removes "m=" lines from the answer for media it didn't 
understand, it should instead write m=<media> 0 according to RFC 3264 
section 6.

2. The origin field
o=<username> <session id> <version> <network type> <address type>
Linphone got a fixed session id "123456" and a version "654321".
This can cause interoperability problems when Linphone is re-inviting as 
the version must then be updated or the receiving client could ignore 
the SDP according to RFC 3264 section 8.

The session id and version should also be unique for every new section.

Solutions:
Modified offer_answer_initiate_incoming so that linphone answers 
m=<media> 0 on media it don't understand

o field:
Randomizing session id and version when a local_media_description is 
created.
Incrementing session version when linphone_core_update_call is called 
with a new set of params and reusing the old session id.

Best Regards,
Martin Hörlin

linphone_sdp.patch
Description: Text document