[Users] Checking Request-URI

[Andreas Sikkema]

Klaus,

> Maybe someone sent a SIP message with the local IP address in 
> the R-URI 
> to your proxy. According to your config this should not matter as you 
> rewrite the domain for every incoming SIP request - except 
> for loose-route.

The IP address in the Request-URI is one that for some reason 
(incorrect configuration?) is being sent by the SIP UA. This IP 
address is NOT the same machine as OpenSER...

The loose_route block could indeed be the culprit here. Is there a 
way I can see in an INVITE being sent to OpenSER that loose_route() will

return true?

This is the (sanitized) INVITE that is causing the problems:

INVITE sip:[NUMBER]@[WRONG_IP_ADDRES] SIP/2.0
Call-ID: 6181509477cc0df82db6313a276492d5@[SIP_DOMAIN]
From: <sip:[USERNAME]@[IPADDRESS_PROXY]:[PROXYPORT]>;tag=45fa8
To: "[NUMBER]" <sip:[NUMBER]@[SIP_DOMAIN]>;tag=as52bb63c2
CSeq: 101 INVITE
Via: SIP/2.0/UDP
10.1.2.71:5060;branch=z9hG4bK-45a33f186083645f5232ca79048af818
Contact: "[USERNAME]" <sip:[USERNAME]@10.1.2.71:5060>
Max-Forwards: 70
Route: <sip:[IPADDRESS_PROXY]:[PROXYPORT];lr>
User-Agent: [USER_AGENT]
Supported: timer
Content-Type: application/sdp
Content-Length: 151

(I've removed the body of the message; it's not very interesting here)

The problem is that the Request-URI contains [WRONG_IP_ADDRESS]. When
this 
OpenSER receives an INVITE it should never forward the INVITE to an IP 
address a SIP UA has added to the Request-URI. OpenSER should be the one

to decide this.

So far we've never had any issues in this area, so I don't want to
change 
too much in the config (like removing the whole loose_route() stuff) 
unless that is the only way I can solve this problem.

If the Request-URI would have been correct, [NUMBER] would have been 
rewritten to something usefull and the call would have succeeded.

> For loose-route I would suggest to check for a to-tag too. Then, the 
> called SIP UA should reject the call. You could also use 
> dialog module 
> to see if a dialog exists before forwarding in loose_route.

How would checking for a to_tag help? There is no existing Ddialog; this

is handling the initial INVITE message where it already goes wrong...

-- 
Andreas Sikkema                        BBeyond
Software Engineer                Planeetbaan 4
+31 (0)23 7074342            2132 HZ Hoofddorp