Query the configured LDAP server with the provided search filter and
        attribute list.

def ldap_search(self, filter, attributes, incremental, incremental_filter):
        """
        Query the configured LDAP server with the provided search filter and
        attribute list.
        """
        for uri in self.conf_LDAP_SYNC_BIND_URI:
            #Read record of this uri
            if (self.working_uri == uri):
                adldap_sync = self.working_adldap_sync
                created = False
            else:
                adldap_sync, created = ADldap_Sync.objects.get_or_create(ldap_sync_uri=uri)

            if ((adldap_sync.syncs_to_full > 0) and incremental):
                filter_to_use = incremental_filter.replace('?', self.whenchanged.strftime(self.conf_LDAP_SYNC_INCREMENTAL_TIMESTAMPFORMAT))
                logger.debug("Using an incremental search. Filter is:'%s'" % filter_to_use)
            else:
                filter_to_use = filter

            ldap.set_option(ldap.OPT_REFERRALS, 0)
            #ldap.set_option(ldap.OPT_NETWORK_TIMEOUT, 10)
            l = PagedLDAPObject(uri)
            l.protocol_version = 3

            if (uri.startswith('ldaps:')):
                l.set_option(ldap.OPT_X_TLS, ldap.OPT_X_TLS_DEMAND)
                l.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_DEMAND)
                l.set_option(ldap.OPT_X_TLS_DEMAND, True)
            else:
                l.set_option(ldap.OPT_X_TLS, ldap.OPT_X_TLS_NEVER)
                l.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_NEVER)
                l.set_option(ldap.OPT_X_TLS_DEMAND, False)
            try:
                l.simple_bind_s(self.conf_LDAP_SYNC_BIND_DN, self.conf_LDAP_SYNC_BIND_PASS)
            except ldap.LDAPError as e:
                logger.error("Error connecting to LDAP server %s : %s" % (uri, e))
                continue

            results = l.paged_search_ext_s(self.conf_LDAP_SYNC_BIND_SEARCH, ldap.SCOPE_SUBTREE, filter_to_use, attrlist=attributes, serverctrls=None)
            l.unbind_s()
            if (self.working_uri is None):
                self.working_uri = uri
                self.conf_LDAP_SYNC_BIND_URI.insert(0, uri)
                self.working_adldap_sync = adldap_sync

            return (uri, results)  # Return both the LDAP server URI used and the request. This is for incremental sync purposes
        #if not connected correctly, raise error
        raise