ldap paged search

gistfile1.py

#!/usr/bin/python
# samples
#  http://www.grotan.com/ldap/python-ldap-samples.html
# useraccountcontrol
#  http://msdn.microsoft.com/en-us/library/windows/desktop/ms680832(v=vs.85).aspx
# paging search
#  http://www.novell.com/coolsolutions/tip/18274.html

import ldap
from ldap.controls import SimplePagedResultsControl

class LDAPConf:
   '''
   This contains all details that pertain to our ldap instance
   '''
   url = 'changeme'
   # don't chase referrals since MSAD does not like it.
   chase_referrals = 0
   protocol_version = ldap.VERSION3
   bind_dn = 'changeme'
   bind_password = 'changeme'
   base_dn = 'changeme'
   search_scope = ldap.SCOPE_SUBTREE
   # search all active accounts
   search_filter = '(&(objectcategory=person)(objectclass=user)'\
      '(!(|(useraccountcontrol:1.2.840.113556.1.4.803:=2)'\
          '(useraccountcontrol:1.2.840.113556.1.4.803:=65536))))'
   # retrieve all attributes
   retrieve_attrs = None
   # page search results
   page_size = 100
   # size limit
   size_limit = 0


def connect():
   '''
   setup the connection.
   This should take care of all details that pertain to our ldap instance
   '''
   global conn
   conn = ldap.open(LDAPConf.url)
   conn.set_option(ldap.OPT_REFERRALS, LDAPConf.chase_referrals)
   conn.set_option(ldap.OPT_SIZELIMIT, LDAPConf.size_limit)
   conn.simple_bind_s(LDAPConf.bind_dn, LDAPConf.bind_password)
   conn.protocol_version = LDAPConf.protocol_version


def disconnect():
   '''
   close the connection.
   This should take care of all details that pertain to our ldap instance
   '''
   conn.unbind_s()


class SearchCounter(object):
   '''
   Simple callback counter.
   For non-paged search, callback will increase the counts.
   '''
   def __init__(self):
      self.result_count, self.ref_count = 0, 0
   def callback(self, result_type, result_data):
      '''
      handle a search result.
      This will increment the appropriate counter.
      '''
      if result_type == ldap.RES_SEARCH_ENTRY:
         self.result_count += 1
      elif result_type == ldap.RES_SEARCH_REFERENCE:
         self.ref_count += 1


def search(result_callback, *args, **kwargs):
   '''
   Simple non-paged search.
   See ldap.search_ext for parameters.
   See ldap.result for callback parameters.
   '''
   ldap_result_id = conn.search_ext(*args, **kwargs)
   try:
      while True:
         result_type, result_data = conn.result(ldap_result_id, 0)
         if result_data == []:
            break
         result_callback(result_type, result_data)
   except ldap.SIZELIMIT_EXCEEDED:
      conn.abandon_ext(ldap_result_id)


def paged_search(*args, **kwargs):
   '''
   Paged search.
   This is a generator function which will yield results one at a time.
   See ldap.search_ext for parameters.
   See ldap.result3 for implementation details.
   '''
   results_control = SimplePagedResultsControl(
        ldap.LDAP_CONTROL_PAGE_OID, True, (LDAPConf.page_size, ''))
   while True:
      serverctrls = [results_control]
      msgid = conn.search_ext(*args, serverctrls=serverctrls, **kwargs)
      _, results, _, serverctrls = conn.result3(msgid=msgid)
      for result in results:
         yield result
      cookie = None 
      # look for the cookie to continue the search
      for serverctrl in serverctrls:
         if serverctrl.controlType == ldap.LDAP_CONTROL_PAGE_OID:
            _, cookie = serverctrl.controlValue
            if cookie:
               results_control.controlValue = (LDAPConf.page_size, cookie)
            break
      # no cookie = search complete.
      if not cookie:
         break


# example
if __name__ == '__main__':
   try:
      connect()
      counter = SearchCounter()
      search(counter.callback,
         LDAPConf.base_dn, LDAPConf.search_scope,
         LDAPConf.search_filter, LDAPConf.retrieve_attrs)
      print 'result_count', counter.result_count
      count = 0
      for item in paged_search(
         LDAPConf.base_dn, LDAPConf.search_scope,
         LDAPConf.search_filter, LDAPConf.retrieve_attrs):
         count += 1
      print 'paged_result_count', count
      print 'last item', item
   except ldap.LDAPError, e:
      print e
      raise
   finally:
      disconnect()