File Descriptor Leak in Freebsd 4.9 - any known issue?

[punit gupta]

Hi,

Has there been any known issue regarding socket-descriptor leak in Freebsd4.9? 

In my application I am using openldap client library to authenticate users with ldap-server. Whenever an authentication request comes, the application opens a socket to backend ldap server and then hands over the socket-descriptor to ldap-client-library. ldap-client-library takes care of communicating with ldap-server and later calls 'unbind' that also closes the connection. 

Now, the problem I am facing is this - I observed that the number of sockets opened by the application to backend ldap-server keeps growing constantly. These open sockets keep lingering even when there is no activity happening for a long time (e.g. no authentication request coming for hours). This is many times leading to the error "kern.maxfiles limit reached by uid ..." and then system stops functioning. 

I was wondering if there can be a problem with open-ldap-library and it is not calling 'unbind' in some cases; but then I observed that the issue does not occur when I run same application on Freebsd6.3. Even if there was a problem with ldap-library then also how can a socket remain open for hours without any activity happening on it - shouldn't it be timing out at some time?

Kindly let me know if you have an idea on what might be happening or what could be the fix. Any help is much appreciated.

Thanks,
Punit