Re: (ITS#3528) add time limit options for bind and exop requests

[Kurt@OpenLDAP.org]

> If I'm reading the code right, all bind requests
> and exop requests issued by libldap are allowed
> to block indefinitely.

You are not reading the code correctly.  Only ldap_*_s() functions
wait indefinitely for the server response (by design).  The async
calls, such as ldap_sasl_bind(3) and ldap_extended_operation(3), do
not wait for response (by design), instead the caller to obtain the
response(s) using ldap_result(3) (which takes a timeout parameter).

I note that there are some higher level calls which may
only provide sync or async APIs.  Generally, there are reasons
behind this.  Likely, just inserting a timeout is not the
complete (or proper) way of providing the desired behavior.
That is, likely it would be better to design, say,
ldap_start_tls() than to add timeouts to ldap_start_tls_s().

-- Kurt