Hello Community,
We were facing a weird issue in one of our Kamailio servers where custom htable entries
were removed which did not belong to a particular call.
Background Information:
We use htable to store the call-id and a uuid when an INVITE message is received and
remove these entries when the call is completed/failed (so on CANCEL, BYE, 4XX, 5XX, 6XX,
etc).
In this case the function sht_rm_name_re was causing incremented call-id's belonging
to different calls to be removed from the htable, since the removal is based on regex and
not the exact key.
On INVITE we do this:
$var(reference) = $uuid(g);
$sht(calls=>$ci) = $ci;
$sht(calls=>$ci::reference) = $var(reference);
On BYE/4XX,5XX,6XX, etc we did this:
sht_rm_name_re("calls=>$ci");
sht_rm_name_re("calls=>$ci::reference");
SIPP generates incremented call-id's, like this:
1-14875@1.0.0.1<mailto:1-14875@1.0.0.1>.
When you generate enough calls, for instance 30 calls, the 21st call will have the call-id
21-14875@1.0.0.1<mailto:21-14875@1.0.0.1>.
If for instance the BYE for the call-id 1-14875@1.0.0.1<mailto:1-14875@1.0.0.1>
arrives before 21-14875@1.0.0.1<mailto:21-14875@1.0.0.1> , both htable entries will
be removed by the sht_rm_name_re function, since it matches based on regex.
To fix this we made sure the function matches on the exact keys by doing this:
$var(callid) = '^' + $ci + '$';
$var(callid_reference) = '^' + $ci + '::reference' + '$';
sht_rm_name_re("calls=>$var(callid)");
sht_rm_name_re("calls=>$var(callid_reference)");
Hope this may help someone in the future facing the same issue.
Regards,
Grant Bagdasarian
CM