Re: [SR-Users] Setting Kamailio User-Agent dynamically

Btw, there is a global parameter to disable server signatures:

- http://www.kamailio.org/wiki/cookbooks/devel/core#server_signature

According to the code, it affect USER-Agent when generating a request and Server header for replies.

Turn it of and can get rid of the workaround with custom header name.

Cheers, Daniel

On 09/10/14 13:52, Daniel-Constantin Mierla wrote:

Hello,

On 09/10/14 13:19, Errol Samuels wrote:

...

HI Daniel,

Thanks for that.

In my case I would need to use something like:

user_agent_header = "X-Proxy: $ua"

The only purpose of the above line is that Kamailio doesn't add an User-Agent header by itself, but this X-Proxy (which you can change as well).

Then you still add User-Agent in $uac_req(hdrs), but you don't end up with two User-Agent headers anymore.

Hope is more clear now the purpose of X-Proxy header.

Cheers, Daniel

...

since we don't what to hardcode a specific value which would affect every device that is registering but rather $ua which would set the real UA of the device that is registering at that time.

Does that make sense?

regards,

Errol

On Thu, Oct 9, 2014 at 12:09 PM, Daniel-Constantin Mierla <miconda@gmail.com mailto:miconda@gmail.com> wrote:

On 08/10/14 19:25, Errol Samuels wrote:

...

I followed Daniel's instructions and made some progress but not
100% there yet.

-------[Global section]----------

user_agent_header=""

-------[Main Routing Logic]-------

# handle registrations
        if (is_method("REGISTER"))
        {
        $avp(new_user_agent) = $ua;
        }
        route(REGISTRAR);
.
.

# Forward REGISTER to Freeswitch
route[REGFWD] {

        if(!is_method("REGISTER"))
        {
                return;
        }
        route(DISPATCH);
        $uac_req(method)="REGISTER";
        $uac_req(ruri)=$du;
        $uac_req(furi)=$fn + "<sip:" + $au + "@" + $ar + ">";
        $uac_req(turi)=$tn + "<sip:" + $au + "@" + $ar + ">";
        $uac_req(hdrs)="Contact: <sip:" + $au + "@"
                                + $ar
                                + ";fs_path=sip:"
                                + $sel(cfg_get.kamailio.bindip)
                                + ":" +
$sel(cfg_get.kamailio.bindport)
                                + ">"
                                + "\r\n";
        if($sel(contact.expires) != $null)
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " +
$sel(contact.expires) + "\r\n";
        else
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " +
$hdr(Expires) + "\r\n";
        $uac_req(hdrs)= $uac_req(hdrs) + "User-Agent: " +
$avp(new_user_agent) + "\r\n";
        uac_req_send();
        exit;
}
#!endif

------------

Now the correct User-Agent appears in the REGISTER message but
in Freeswitch it shows as unknown.

U 184.xx.xx.208:5060 -> 184.xx.xx.198:6060
REGISTER sip:184.x.x.198:6060 SIP/2.0.
Via: SIP/2.0/UDP 184.xx.xx.208;branch=z9hG4bKa764.668d6dc7.0.
To: <sip:1001@pbx.mydomain.com
<mailto:sip%3A1001@pbx.mydomain.com>>.
From: <sip:1001@pbx.mydomain.com
<mailto:sip%3A1001@pbx.mydomain.com>>;tag=6f72f76f3402bf7cf11f6917529ca761-2ceb.
CSeq: 10 REGISTER.
Call-ID: 4570a277563cdffc-61869@184.xx.xx.208
<mailto:4570a277563cdffc-61869@184.xx.xx.208>.
Max-Forwards: 70.
Content-Length: 0.
.
Contact: <sip:1001@pbx.mydomain.com
<mailto:sip%3A1001@pbx.mydomain.com>;fs_path=sip:184.xx.xx.208:5060>.
Expires: 120.
User-Agent: Yealink SIP-T46G 28.72.0.26.
.
----------------

Got some extra dots in there but not sure why they are there and
how they got there.
Any ideas? Anything I missed?

Apparently by setting an empty user-agent header value in
kamailio config file results in an empty line in headers, which
means end of headers. So it kind of breaks the headers -- I will
fix that in kamailio.

A solution for now will be to use:

user_agent_header = "X-Proxy: abc"

Or, in other words, set the value of the parameter to something
that doesn't include User-Agent: as header name.

Cheers,
Daniel

...

BR

Errol



On Wed, Oct 8, 2014 at 12:34 PM, Daniel-Constantin Mierla
<miconda@gmail.com <mailto:miconda@gmail.com>> wrote:

    Perhaps you can get it with adding User-Agent header to
    $uac_req(hdrs):

    $uac_req(hdrs)= $uac_req(hdrs) + "User-Agent: " + $ua + "\r\n";

    And sent the global parameter:

    user_agent_header=""

    But then no local generated request has user agent, which
    probably is ok for you.

    There are still ways to use event_route[tm:local-request] to
    set a custom user agent header, but would require something
    like:
    - add $us in $uac_req(hdrs) as X-UA header
    - in event_route[tm:local-request], remove User-Agent and
    X-UA headers and add again User-Agent taking the value from X-UA

    Cheers,
    Daniel

-- 
Daniel-Constantin Mierla
http://twitter.com/#!/miconda  <http://twitter.com/#%21/miconda>  -http://www.linkedin.com/in/miconda

-- Daniel-Constantin Mierla http://twitter.com/#!/miconda -http://www.linkedin.com/in/miconda