(ITS#4524) [enhancement] handling of failed connections in proxy backends

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD
OS: irrelevant
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (87.28.220.33)
Submitted by: ando


As a follow-up to this thread,
<http://www.openldap.org/lists/openldap-devel/200604/msg00046.html>
I've committed an improvement to libldap that allows to modify the URI sequence
after a connection is established.  By default nothing happens; however,
back-ldap and back-meta have been modified to exploit this feature in a manner
that consists in moving the failed URIs at the end of the list.  More
sophisticated behavior can be implemented by modifying the callback.

The change affects libldap and the proxy backends; some URI handling function
declarations have been moved from libraries/libldap/ldap-int.h into
include/ldap_pvt.h and a new ldap_set_urllist_proc() has been added.

Right now, a default behavior consisting in moving the contacted URI to the head
of the list is hardcoded in both backends, as it is believed to be beneficial. 
The reordering is not reflected in back-config, so the reordering vanishes when
the server is stopped; however, run-time modifications to back-config result in
resetting the URI list.

p.