[SR-Users] Contact header modification - Kamailio

Yuriy Gorlichenko ovoshlook at gmail.com
Thu Aug 4 09:09:29 CEST 2022


it looks like you are handling contact manually but also call
"fix_nated_contact/add_contact_alias" function as well.
You can't call 2 functions for the same header - it breaks the logic of how
kamailio deals with the config at the postprocessing.
There are 2 ways to fix it:
- remove nat helper functions touching contact ( preferred as you
don't need it anymore for the INVITE flow )
- use msg_apply_changes after the first function (which I would not
recommend as it rereads the message again and defacto Kamailio parses the
same message twice )

However as Alex Balashow mentioned - this is a really bad approach - to
rewrite contact on the proxy, and it has to be used for corner cases and
you are not at one of them.
You have to deal with Record-Route/Route headers to be able to manage the
routing.


чт, 4 авг. 2022 г. в 07:30, Ankit Jayswal <ankit.jayswal at engagely.ai>:

> Yes,
> When I use *remove_hf()* and *insert_hf()* it doesn't remove the value of
> the Contact header properly.
>
> Below code executed:
> remove_hf("Contact");
> insert_hf("Contact: <sip:00912269240500 at 10.52.26.98:5060>\r\n",
> "Contact");
>
> I have given the sngrep INVITE request below after applying the above
> code. See the highlighted contact header not removing previous value
> properly.
>
> [image: contact_header.png]
>
>
>
>
> On Wed, Aug 3, 2022 at 8:30 PM Alex Balashov <abalashov at evaristesys.com>
> wrote:
>
>> How did you conclude that it doesn’t work?
>>
>> > On Aug 3, 2022, at 8:06 AM, Ankit Jayswal <ankit.jayswal at engagely.ai>
>> wrote:
>> >
>> > Hello,
>> >
>> > Can you suggest directly replacing the value of the Contact header ? As
>> remove_hf("Contact") does not work for me.
>> >
>> > I need just Contact: <sip:009122692405xx at 10.52.26.98:5060> instead of,
>> > Contact: <sip:0091692405xx at 45.118.162.x:5080;alias=10.52.26.102~5080~1>
>> >
>> >
>> > On Tue, Aug 2, 2022 at 12:56 PM Alex Balashov <
>> abalashov at evaristesys.com> wrote:
>> > The suggestion given by Henning was to remove the existing Contact
>> header, and replace it with whatever value you like.
>> >
>> > > On Aug 2, 2022, at 1:12 AM, Ankit Jayswal <ankit.jayswal at engagely.ai>
>> wrote:
>> > >
>> > > Hello,
>> > > Whenever I try the remove_hf("Contact") function the call leg is
>> divided into the two parts and the call is not getting set up properly and
>> not progressing.
>> > > I am just looking for a function that can modify the Contact header
>> value of an existing Contact header.
>> > >
>> > > On Mon, Aug 1, 2022 at 8:31 PM Henning Westerholt <hw at gilawa.com>
>> wrote:
>> > > Hello,
>> > >
>> > >
>> > >
>> > > you need to do a “remove_hf(“Contact”)” before.
>> > >
>> > >
>> > >
>> > > Cheers,
>> > >
>> > >
>> > >
>> > > Henning
>> > >
>> > >
>> > >
>> > > --
>> > >
>> > > Henning Westerholt – https://skalatan.de/blog/
>> > >
>> > > Kamailio services – https://gilawa.com
>> > >
>> > >
>> > >
>> > > From: Ankit Jayswal <ankit.jayswal at engagely.ai>
>> > > Sent: Monday, August 1, 2022 4:26 PM
>> > > To: Henning Westerholt <hw at gilawa.com>
>> > > Cc: Kamailio (SER) - Users Mailing List <sr-users at lists.kamailio.org>;
>> Amey Naik <amey.naik at engagely.ai>; Devanand Jalla <
>> devanand.jalla at engagely.ai>
>> > > Subject: Re: [SR-Users] Contact header modification - Kamailio
>> > >
>> > >
>> > >
>> > > Hello,
>> > > Thanks for your reply, but I am looking to replace the value in the
>> Contact header. Which function can help me to do this ?
>> > > I tried,
>> > > assign_hf_value("Contact", "<sip:00912269240xxx at 10.52.26.98:5060>");
>> > >
>> > >
>> > > But that is not working properly, it assigns value but previous value
>> also remains in it.
>> > >
>> > >
>> > >
>> > > On Mon, Aug 1, 2022 at 6:11 PM Henning Westerholt <hw at gilawa.com>
>> wrote:
>> > >
>> > > Hello,
>> > >
>> > >
>> > >
>> > > the topos module can do that, among other things. Alternatively there
>> is also the topoh module, which do not need any backend storage.
>> > >
>> > >
>> > >
>> > > Cheers,
>> > >
>> > >
>> > >
>> > > Henning
>> > >
>> > >
>> > >
>> > > --
>> > >
>> > > Henning Westerholt – https://skalatan.de/blog/
>> > >
>> > > Kamailio services – https://gilawa.com
>> > >
>> > >
>> > >
>> > > From: sr-users <sr-users-bounces at lists.kamailio.org> On Behalf Of
>> Ankit Jayswal
>> > > Sent: Monday, August 1, 2022 2:37 PM
>> > > To: sr-users at lists.kamailio.org
>> > > Cc: Amey Naik <amey.naik at engagely.ai>; Devanand Jalla <
>> devanand.jalla at engagely.ai>
>> > > Subject: [SR-Users] Contact header modification - Kamailio
>> > >
>> > >
>> > >
>> > > Hello Team,
>> > >
>> > > I am in need to modify the contact header in Kamailio before sending
>> an INVITE request to the SIP trunk provider. Basically the IP address I
>> need to modify in the contact header. Please suggest a better way to do
>> this. Below is an example.
>> > >
>> > > OLD (Existing):
>> > >
>> > > Contact: <sip:009169240xxx at 45.118.162.x
>> :5080;alias=10.52.26.102~5080~1>
>> > >
>> > >
>> > >
>> > > NEW (Needed):
>> > >
>> > > Contact: <sip:00912269240xxx at 10.52.26.98:5060>
>> > >
>> > > I tried various functions from the textops module but no hope.
>> > > I am looking for a function that can replace the contact header's
>> value. Please help me with this.
>> > >
>> > >
>> > >
>> > > --
>> > >
>> > > Thanks & Regards,
>> > > Ankit Jayswal | Specialist - Software Development
>> > >
>> > > __________________________________________________________
>> > > Kamailio - Users Mailing List - Non Commercial Discussions
>> > >  * sr-users at lists.kamailio.org
>> > > Important: keep the mailing list in the recipients, do not reply only
>> to the sender!
>> > > Edit mailing list options or unsubscribe:
>> > >  * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>> >
>> > --
>> > Alex Balashov | Principal | Evariste Systems LLC
>> >
>> > Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
>> > Web: http://www.evaristesys.com/, http://www.csrpswitch.com/
>> >
>> >
>> > __________________________________________________________
>> > Kamailio - Users Mailing List - Non Commercial Discussions
>> >   * sr-users at lists.kamailio.org
>> > Important: keep the mailing list in the recipients, do not reply only
>> to the sender!
>> > Edit mailing list options or unsubscribe:
>> >   * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>> > __________________________________________________________
>> > Kamailio - Users Mailing List - Non Commercial Discussions
>> >  * sr-users at lists.kamailio.org
>> > Important: keep the mailing list in the recipients, do not reply only
>> to the sender!
>> > Edit mailing list options or unsubscribe:
>> >  * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>
>> --
>> Alex Balashov | Principal | Evariste Systems LLC
>>
>> Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
>> Web: http://www.evaristesys.com/, http://www.csrpswitch.com/
>>
>>
>> __________________________________________________________
>> Kamailio - Users Mailing List - Non Commercial Discussions
>>   * sr-users at lists.kamailio.org
>> Important: keep the mailing list in the recipients, do not reply only to
>> the sender!
>> Edit mailing list options or unsubscribe:
>>   * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>
> __________________________________________________________
> Kamailio - Users Mailing List - Non Commercial Discussions
>   * sr-users at lists.kamailio.org
> Important: keep the mailing list in the recipients, do not reply only to
> the sender!
> Edit mailing list options or unsubscribe:
>   * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>
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