[Blink] Blink over VPN using the wrong ip address in headers

[Christian Kujau]

Hi,

maybe this has been reported already, but I could not find any 
(searchable) archives or a bugtracker. Does a bugtacker for Blink exist?

This is basically the same bug that is present for another SIP client, 
called telephone: https://code.google.com/p/telephone/issues/detail?id=187

In short: when I'm using Blink (0.24.0, MacOS 10.6.7) to connect to a SIP 
server via a VPN connection (Tunnelblick using OpenVPN), Blink uses my 
/local/ address within its SIP traffic instead of my VPN address.

A few details on that:

-------------------------------
# ifconfig  | egrep -A1 '^(en1|tun0)'
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 192.168.0.103 netmask 0xffffff00 broadcast 192.168.0.255
--
tun0: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 10.9.2.70 --> 10.9.2.69 netmask 0xffffffff 
-------------------------------

With the VPN being UP, I now have a second address, 10.9.2.70. This is the 
only address that could be used for my SIP server within that VPN, 
10.0.0.54. However, tcpdump and Blink's own Activiy/SIP logs show that my 
local address, 192.168.0.103 is used instead:

-------------------------------
# tcpdump -i tun0 -tttt -v not port '53 or 123' 
tcpdump: listening on tun0, link-type NULL (BSD loopback), capture size 
65535 bytes
2011-05-11 13:55:14.932116 IP (tos 0x0, ttl 64, id 27697, offset 0, flags 
[none], proto UDP (17), length 443)
    10.9.2.70.53114 > 10.0.0.54.sip: SIP, length: 415
        REGISTER sip:10.0.0.54 SIP/2.0
        Via: SIP/2.0/UDP 192.168.0.103:53114;rport;branch=z9hG4bKPj6ML44wC9jVdKC704G08ffgijZwcC7di.
        Max-Forwards: 70
        From: "ck" <sip:356 at 10.0.0.54>;tag=Ge5mGwv7mrlTA-E5SuFdTkWnQZU1EtsZ
        To: "ck" <sip:356 at 10.0.0.54>
        Contact: <sip:jfsgbvhp at 10.9.2.70:53114>
        Call-ID: OMSbfSeoRs4S-YaeiBWhSq-Zho.FuHwn
        CSeq: 1 REGISTER
        Expires: 600
        User-Agent: Blink 0.24.0 (MacOSX)
        Content-Length:  0
-------------------------------

The activity log says:

-------------------------------
2011-05-11 13:58:55   Account('356 at 10.0.0.54') activated
2011-05-11 13:59:05   Account('356 at 10.0.0.54') failed to register: No more 
routes to try (retrying in 49.77 seconds)
2011-05-11 13:59:05   Error: The account 356 at 10.0.0.54 failed to 
register(No more routes to try)
2011-05-11 13:59:10   Account('356 at 10.0.0.54') deactivated
-------------------------------

Is there some (secret?) setting that tells Blink which IP address to use 
for SDP/SIP messages?

Thanks,
Christian.
-- 
BOFH excuse #3:

electromagnetic radiation from satellite debris