kamailio 5.4.5: "0 ID or NULL NAME AVP!" in lcr module

[mdyrna]

Description

After upgrading kamailio from 5.4.4 to 5.4.5, the lcr module logs an error for outgoing calls. load_gws returns success (1), but does not populate the avps. Consequently, next_gw fails.

Troubleshooting

Reproduction

kamailio.cfg:

loadmodule "lcr.so"

...

modparam("lcr", "db_url", "cluster://cls1")
modparam("lcr", "gw_uri_avp", "$avp(i:709)")
modparam("lcr", "ruri_user_avp", "$avp(i:500)")
modparam("lcr", "tag_avp", "$avp(lcr_tag)")
modparam("lcr", "flags_avp", "$avp(i:712)")
modparam("lcr", "defunct_capability", 1)
modparam("lcr", "lcr_id_avp", "$avp(s:lcr_id_avp)")
modparam("lcr", "defunct_gw_avp", "$avp(s:defunct_gw_avp)")
modparam("lcr", "ping_interval", 60)

...

route[LCR] {
        if(!($rU=~"^[+0-9]"))
                return;

        if(is_method("INVITE")) {
                if (!($fU=~"^[+0-9]+$")) {
                        append_hf("P-Asserted-Identity: <sip:+49xxxxxxxxxxx@xxxxx.de>\n");
                        append_hf("Privacy: id\n");
                        $fn = "Anonymous";
                        $fu = "sip:+49xxxxxxxxxxx@xxxxx.de";
                }

                if(load_gws(1, $rU, $var(caller_uri)) != 1) {
                        xlog("L_ERROR", "Couldn't load gateways\n");
                        sl_send_reply("500", "Server Internal Error - Cannot load gateways");
                        exit;
                } else {
                        xlog("L_INFO", "GW Selected '$avp(i:709)'\n");
                        xlog("L_INFO", "Domain of destination: $dd\n");
                        xlog("L_INFO", "To URI: $tu\n");
                }

                if(!next_gw()) {
                        xlog("L_WARN", "No gateway configured for $rU\n");
                        sl_send_reply("503", "Service not available, no gateways found");
                        exit;
                } else {
                        xlog("L_INFO", "Calling the first matched gateway\n");
                        xlog("L_INFO", "ruri_user_avp: '$avp(i:500)'\n");
                        xlog("L_INFO", "To URI after next_gw: $tu\n");
                        xlog("L_INFO", "Request URI: $ru\n");
                }

                t_on_failure("MANAGE_FAILURE_LCR");
                route(RELAY);
                exit;
        }
}

Debugging Data

Log Messages

Apr 15 20:59:27 x /usr/sbin/kamailio[879]: ERROR: <core> [core/usr_avp.c:152]: create_avp(): 0 ID or NULL NAME AVP!
Apr 15 20:59:27 x /usr/sbin/kamailio[879]: ERROR: <core> [core/usr_avp.c:152]: create_avp(): 0 ID or NULL NAME AVP!
Apr 15 20:59:27 x /usr/sbin/kamailio[879]: INFO: <script>: GW Selected '<null>'
Apr 15 20:59:27 x /usr/sbin/kamailio[879]: INFO: <script>: Domain of destination: <null>
Apr 15 20:59:27 x /usr/sbin/kamailio[879]: INFO: <script>: To URI: sip:+49177xxxxxxx@xx.xxx.x.xxx:5060
Apr 15 20:59:27 x /usr/sbin/kamailio[879]: WARNING: <script>: No gateway configured for +49177xxxxxxx

SIP Traffic

SIP request:

        INVITE sip:+49177xxxxxxx@xx.xx.xx.xxx:5060 SIP/2.0
        Via: SIP/2.0/UDP xxx.xx.xx.xxx:xxxxx;branch=z9hG4bK5d833a50
        Max-Forwards: 70
        From: <sip:+xxxxxxxxxxx@xxx.xx.xx.xxx:xxxxx>;tag=as18ff0d47
        To: <sip:+49177xxxxxxx@xx.xx.xx.xxx:5060>
        Contact: <sip:+xxxxxxxxxxx@xxx.xx.xx.xxx:xxxxx>
        Call-ID: 7489c50703b43b2f03980574181a2f81@xxx.xx.xx.xxx:xxxxx
        CSeq: 102 INVITE
        User-Agent: Asterisk PBX 13.18.3~dfsg-1ubuntu4
        Date: Thu, 15 Apr 2021 21:52:42 GMT
        Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
        Supported: replaces, timer
        Content-Type: application/sdp
        Content-Length: 952

...

SIP reply:

        SIP/2.0 503 Service not available, no gateways found
        Via: SIP/2.0/UDP xxx.xx.xx.xxx:xxxxx;branch=z9hG4bK5d833a50;rport=50060;received=xx.xx.xx.xxx
        From: <sip:+xxxxxxxxxxx@xxx.xx.xx.xxx:xxxxx>;tag=as18ff0d47
        To: <sip:+49177xxxxxxx@xx.xx.xx.xxx:5060>;tag=6a823999ce344a0b461cf8d85d526103.51611a36
        Call-ID: 7489c50703b43b2f03980574181a2f81@xxx.xx.xx.xxx:xxxxx
        CSeq: 102 INVITE
        Server: kamailio (5.4.5 (x86_64/linux))
        Content-Length: 0

Possible Solutions

As a workaround, I downgraded to kamailio 5.3.8 because the previous Ubuntu release 5.4.4 is not available anymore at http://deb.kamailio.org/kamailio54/pool/main/k/kamailio/ (why actually?)

Additional Information

• Kamailio Version 5.4.5
• Operating System: Ubuntu 18.04

Root Cause Assumption

ca18218 might be involved in the issue.

[miconda]

Thanks for reporting, I will look into it, the commit ca18218 was related to a fix on a potential issue reported by a static analyzer/fuzzer.

As a workaround to try for now would be to change the next parameters to use string avp name:

modparam("lcr", "gw_uri_avp", "$avp(s:709)")
modparam("lcr", "ruri_user_avp", "$avp(s:500)")
modparam("lcr", "flags_avp", "$avp(s:712)")

[miconda]

Should be fixed by e450638 in master and backported to 5.4 967dd29.

Can you try with latest git version and report if all ok now?

[mdyrna]

Thanks for your quick reaction.

I can confirm that for both solutions, the lcr module works well:

• Ubuntu 18.04 package 5.4.5 with Integer avp names replaced ('i:' => 's:') (kamailio 5.4.5: "0 ID or NULL NAME AVP!" in lcr module #2709 (comment))
• Compiled from latest git branch 5.4 (kamailio 5.4.5: "0 ID or NULL NAME AVP!" in lcr module #2709 (comment)) with default avp names (i:709, i:500, i:712)

Since I don't want to use the git version in production, I would be grateful for a quick official 5.4.6 release.

Also, I assume this problem may affect most of kamailio 5.4.5 deployments using lcr because the Integer avp names are suggested by the official documentation (https://www.kamailio.org/docs/modules/stable/modules/lcr.html).

[miconda]

Thanks for testing and confirming the fix and the workaround!

There are nightly builds from the 5.4.x branch:

• http://deb.kamailio.org/#dev54

It is what you can use to get the fix in deb packages. There will be a 5.4.6 at some point, but for packaging pointing view that's just to have a milestone, because the packages for it are from the branch 5.4, exactly as it is done in the nightly ones.

You can also build debs locally, specs are in the pkg/kamailio/deb/ folder.