bug in 4.0.2 dialog module, no keep alives when src==dst - sr-users

19 Jun 2013


      Trying to implement calllimits with the dialog module I can reproduce a 
hanging dialog using a Linksys 962 by calling itself. When trying to answer 
the call the INVITES end in a 200 OK but the call is terminated [linksys.txt].
That might be a bug in the 962, but the bad part is the dialog will be kept in 
kamailio even though keep alives are enabled. OPTIONS are not being sent to 
detect this dead dialog. If this devices calls an other device (either 
registered to this kamailio or to the PSTN) KA work like configured (they are 
being send to this device). Severing the connection will be detected and the 
dialog will be removed. But when source and destination is the same device, no 
OPTIONS are sent.
About 1 hour later the dialog is still there:
# kamctl mi dlg_list
dialog::  hash=3456:6742
        state:: 3
        ref_count:: 2
        timestart:: 1371572203
        timeout:: 68536211
        callid:: 86a23723-4b71d5ad@localhost
        from_uri:: sip:anonymous@localhost
        from_tag:: 1736b8ab3ea801c5o0
        caller_contact:: sip:+31880100781@10.0.34.226:17852
        caller_cseq:: 102
        caller_route_set:: 
        caller_bind_addr:: udp:10.0.32.42:5060
        callee_bind_addr:: udp:10.0.32.42:5060
        to_uri:: sip:0880100781@10.0.32.42
        to_tag:: 195218c1d50330b5i0
        callee_contact:: sip:+31880100781@10.0.34.226:17852
        callee_cseq:: 102
        callee_route_set::
A part of syslog with debug=4 for above dialog is attached (not the same 
dialog as the attached linksys capture).
Relevant kamailio.cfg parts:
modparam("dialog","dlg_flag",4)
modparam("dialog","hash_size",4096)
modparam("dialog","enable_stats",1)
modparam("dialog","db_url",DBURL)
modparam("dialog","db_mode", 2)
modparam("dialog","db_update_period", 15)
modparam("dialog","profiles_with_value","channelsinbound;channelsoutbound")
modparam("dialog","profiles_no_value", "all")
modparam("dialog","dlg_match_mode", 1)
modparam("dialog","send_bye", 1)
modparam("dialog","default_timeout", 43200)
modparam("dialog","ka_timer", 45)
modparam("dialog","ka_interval", 45)
routes to DIALIOG in request_route for CANCEL and before route(SIPOUT)
request_route {
# per request initial checks
        route(REQINIT);
# NAT detection
        route(NATDETECT);
# CANCEL processing
        if (is_method("CANCEL"))
        {
                route(DIALOG);
if (t_check_trans())
                {
                        t_relay();
                }
exit;
        }
[...]
        route(DIALOG);
# dispatch requests to foreign domains
        route(SIPOUT);
routes to DIALOG within WITHINDLG
# Handle requests within SIP dialogs
route[WITHINDLG] {
        if (has_totag()) {
                # sequential request withing a dialog should
                # take the path determined by record-routing
                if (loose_route()) {
                        route(DLGURI);
                        if (is_method("BYE")) {
                                route(DIALOG);
[...]
                        route(RELAY);
                } else {
                        route(DIALOG);
[...]
                exit;
        }
}
# active calls/dialog management
route[DIALOG]
{
        if (is_method("CANCEL|ACK|BYE") || (has_totag() && is_method("INVITE|
BYE")))
        {
                dlg_manage();
                return;
        }
if (is_method("INVITE") && !has_totag())
        {
                if($avp(dst_maxchannels))
                {
                        route(MAXCALLSINBOUND);
                }
if($avp(src_maxchannels))
                {
                        route(MAXCALLSOUTBOUND);
                }
dlg_manage();
        }
}
route[MAXCALLSOUTBOUND]
{
        if(method=="INVITE")
        {
                if($au!=$null && $avp(src_maxchannels)>0)
                {
                        $var(channelsinbound) = 0;
                        $var(channelsoutbound) = 0;
                        get_profile_size("channelsinbound", "$au", 
"$var(channelsinbound)");
                        get_profile_size("channelsoutbound", "$au", 
"$var(channelsoutbound)");
if(($var(channelsinbound)+$var(channelsoutbound))>=$avp(src_maxchannels))
                        {
                                send_reply("403","Call limit reached");
                                exit;
                        }
set_dlg_profile("channelsoutbound","$au");
                        dlg_set_property("ka-src");
                }
        }
return;
}
route[MAXCALLSINBOUND]
{
        if(method=="INVITE")
        {
                if($avp(dst_maxchannels)>0)
                {
                        $var(channelsinbound) = 0;
                        $var(channelsoutbound) = 0;
                        get_profile_size("channelsinbound", "$rU", 
"$var(channelsinbound)");
                        get_profile_size("channelsoutbound", "$rU", 
"$var(channelsoutbound)");
if(($var(channelsinbound)+$var(channelsoutbound))>=$avp(dst_maxchannels))
                        {
                                route(CALLREDIRECT);
route(TOVOICEMAIL);
send_reply("486","Call limit reached");
                                exit;
                        }
set_dlg_profile("channelsinbound","$rU");
                        dlg_set_property("ka-dst");
                }
        }
return;
}
version: kamailio 4.0.2 (x86_64/linux) 
flags: STATS: Off, USE_IPV6, USE_TCP, USE_TLS, TLS_HOOKS, USE_RAW_SOCKS, 
DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, 
USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, 
USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES
ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144, MAX_LISTEN 16, 
MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 4MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: unknown 
compiled on 11:28:09 Jun 17 2013 with gcc 4.7.2
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