Reading the Entry Change Control from a Persistent Search

[Mike a. P. M. <mor...@te...>]

Hi all,

I've been experimenting with persistent searching on various LDAP server, 
and seem to have that code down pat.  I've also taken Graham advice from a 
previous post about modifying Net::LDAP::Search to allow me to see (at a 
very high level) the Entry Change Control returned with every entry.

My question is: Is it possible for me to dive into the change control data 
in order to extract it's various values?

Here's how I've defined the 2 controls via asn->prepare() (definitions 
borrowed from 
http://www.ietf.org/proceedings/99jul/I-D/draft-ietf-ldapext-psearch-01.txt ) :

   $asn = Convert::ASN1->new;
   $asn->prepare(<<LDAP_X) or die "asn_prepare: ".$asn->error;

   -- Need to add the following 2 because they aren't defined
   -- anywhere before this (taken from Net::LDAP::ASN)
    LDAPString ::= OCTET STRING -- UTF8String ??
    LDAPDN ::= LDAPString

    PersistentSearch ::= [APPLICATION 98] SEQUENCE {
                      changeTypes INTEGER,
                      changesOnly BOOLEAN,
                      returnECs BOOLEAN
              }

    EntryChangeNotification ::= [APPLICATION 99] SEQUENCE {
                        changeType ENUMERATED {
                                add             (1),
                                delete         (2),
                                modify        (4),
                                modDN       (8) }

                        previousDN   LDAPDN OPTIONAL,     -- modifyDN ops. only
                        changeNumber INTEGER OPTIONAL     -- if supported
              }
LDAP_X

and here's my callback code:

   sub processEntry {
        my ($mesg,$entry) = @_;

        if (! defined $entry){
         warn "search_cb: ".$mesg->error."\n";
        } else {
         print $entry->dn."\n";

         # Updated Net::LDAP::Search with a piece of code on the
         # perl-ldap mailing list that will allow us to get controls
         # from data returned in entries.
         @resp = $mesg->control( LDAP_CONTROL_ENTRYCHANGE );
         my $ecASN = $asn->find('EntryChangeNotification');
         foreach my $r (@resp){
          print "Found control ".$r->type."\n";
         }
        }
         $mesg->pop_entry;
   }

Thanks in advance for the advice,

Mike