Via branch non RFC 3261 compliant

[procedurallygenerated]

Options packet sent from opensips to oversip,

OPTIONS sip:1001@df7jal23ls0d.invalid;rtcweb-breaker=yes;transport=ws;ov-ob=6bce984846 SIP/2.0
Via: SIP/2.0/UDP 10.238.201.229:5060;branch=0
Route: <sip:10.0.0.161:5060;transport=udp;lr;ovid=3869ae8a>,<sip:6bce984846@10.0.0.161:10080;transport=ws;lr;ovid=3869ae8a;ob>
From: sip:pinger@XXX.XXX.XXX.XXX;tag=c1c23161
To: sip:1001@df7jal23ls0d.invalid;rtcweb-breaker=yes;transport=ws;ov-ob=6bce984846
Call-ID: 11693e73-d6...@10.238.201.229
CSeq: 1 OPTIONS
Max-Forwards: 70
Content-Length: 0

Response from oversip to opensips,

SIP/2.0 400 Via branch non RFC 3261 compliant
Via: SIP/2.0/UDP 10.238.201.229:5060;branch=0;received=XXX.XXX.XXX.XXX
From: sip:pinger@XXX.XXX.XXX.XXX;tag=c1c23161
To: sip:1001@df7jal23ls0d.invalid;rtcweb-breaker=yes;transport=ws;ov-ob=6bce984846;tag=a360ead4.29d19ef0
Call-ID: 11693e73-d6...@10.238.201.229
CSeq: 1 OPTIONS
Content-Length: 0
Server: OverSIP/1.4.1

When sending the options packet to non-webrtc clients there is no problem, but when sending it to webrtc clients through oversip, oversip expects the branch tag to have a value.

[procedurallygenerated]

Since this is an options packet it will not need to be re-transmitted so i generated a random 7 digit number for each option packet and appended it to the RFC 3261 string "z9hG4bK". My C skills are not great but this is what i did to fix this for myself, if someone can come up with a better method and commit to the code that will be great.

In modules/nathelper/sip_pinger.h

Line 31:

#include<string.h>

Line 145:

const long MAX_BRANCHID = 9999999;
const long MIN_BRANCHID = 1000000;
long result=(long)(rand()/(float)2147483647 * (MAX_BRANCHID-MIN_BRANCHID) + MIN_BRANCHID);
char branch_id[7];
sprintf(branch_id, "%ld", result);
char branch[22]=";branch=z9hG4bK";
strcat(branch,branch_id);
if ( sipping_method.len + 1 + curi->len + s_len(" SIP/2.0"CRLF) +
    s_len("Via: SIP/2.0/") + st.len + s->address_str.len +
    1 + s->port_no_str.len + strlen(branch) +

Line 180:

append_fix( p, branch);
append_fix( p, CRLF"Route: ");

Line 185:

append_fix( p, branch);
append_fix( p, CRLF"From: ");

[ibc]

2013/12/2 Varun notifications@github.com

When sending the options packet to non-webrtc clients there is no problem,
but when sending it to webrtc clients through oversip, oversip expects the
branch tag to have a value.

Yes, that 's a bug in OpenSIPS as it sets ;branch=0 which is not RFC 3261
compliant.

Iñaki Baz Castillo
ibc@aliax.net

[bogdan-iancu]

Point taken ! varunvairavan idea is ok, I will integrate it into the code.

Thank too all for report and comments.

[saghul]

FWIW, I think nat_traversal does the same. @ibc shouldn't OverSIP be gentle in what it accepts? ;-)

[bogdan-iancu]

Hi, the fix was uploaded on trunk. I tested the nathelper part, but I would appreciate @saghul if you could test the nat_traversal part too.
Once you ( @varunvairavan and @saghul ) can confirm the fix, I will make the backports.

Thanks,
Bogdan

[saghul]

I have not tested the code, but looks good to me :-)

[procedurallygenerated]

1f18541 The int2bstr took a fews mins to wrap around my head. Looks good. Thank you for the fast turn around.

[bogdan-iancu]

Backport done, closing....