[Kamailio-Devel] New TM parameter: "drop_stateless_replies"

[Iñaki Baz Castillo]

Hi, I've added a new paratemer to TM module:

  drop_stateless_replies (BOLEAN)

If enabled, when Kamailio receives a reply with no matching transaction it's 
dropped instead of being forwarded stateless based on Via header. This is 
based on draft-sparks-sip-invfix-03 which fixes some issues in RFC 3261 about 
transactions.

It seems to work, but I would like someone to review the code before 
commiting.

Basically I've added the following code to "reply_received()" function 
in "t_reply.c":

------------------------
 not_found:
        set_t(T_UNDEFINED);
+       /* if drop_stateless_replies is enabled then replies no
+        * matching a client transaction are dropped instead of
+        * being forwarded stateless based on Via header.
+        */
+       if (drop_stateless_replies) {
+               LM_DBG("reply with no transaction -> drop\n");
+               return 0;
+       }
        return 1;
 }
-------------------

Any comment please?

PD: By default it's dissabled but I really think it should be enabled by 
default (it avoids an attacker sending responses with spoofed Via).



-- 
Iñaki Baz Castillo