#!/usr/bin/python

#
# Script to check LDAP syncrepl replication state between two servers.
# One server is consider as provider and the other as consumer.
#
# This script can check replication state with two method :
#  - by the fisrt, entryCSN of all entries of LDAP directory will be
#    compare between two servers
#  - by the second, all values of all atributes of all entries will
#    be compare between two servers.
#
# In all case, contextCSN of servers will be compare and entries not
# present in consumer or in provider will be notice. You can decide to
# disable contextCSN verification by using argument --no-check-contextCSN.
#
# This script is also able to "touch" LDAP object on provider to force
# synchronisation of this object. This mechanism consist to add '%%TOUCH%%'
# value to an attribute of this object and remove it just after. The
# touched attribute is specify by parameter --touch. Of course, couple of
# DN and password provided, must have write right on this attribute.
#
# If your prefer, you can use --replace-touch parameter to replace value
# of touched attribute instead of adding the touched value. Use-ful in
# case of single-value attribute.
#
# This script could be use as Nagios plugin (-n argument)
#
# Requirement:
# A single couple of DN and password able to connect to both server
# and without restriction to retrieve objects from servers.
#
# Author: Benjamin Renard <brenard@easter-eggs.com>
# Date: Mon, 10 Dec 2012 18:04:24 +0100
# Source: http://git.zionetrix.net/check_syncrepl_extended
#

import argparse
import logging
import sys

import getpass

import ldap
from ldap import LDAPError  # pylint: disable=no-name-in-module
from ldap.controls import SimplePagedResultsControl
import ldap.modlist as modlist

TOUCH_VALUE = '%%TOUCH%%'

parser = argparse.ArgumentParser(
    version="""%prog version 1.1

Date: Fri, 18 Dec 2020 10:48:45 +0100
Author: Benjamin Renard <brenard@easter-eggs.com>
Source: https://gogs.zionetrix.net/bn8/check_syncrepl_extended
"""
)

parser.add_argument(
    "-p", "--provider",
    dest="provider",
    action="store",
    type=str,
    help="LDAP provider URI (example: ldaps://ldapmaster.foo:636)"
)

parser.add_argument(
    "-c", "--consumer",
    dest="consumer",
    action="store",
    type=str,
    help="LDAP consumer URI (example: ldaps://ldapslave.foo:636)"
)

parser.add_argument(
    "-i", "--serverID",
    dest="serverid",
    action="store",
    type=int,
    help="Compare contextCSN of a specific master. Useful in MultiMaster setups where each master has a unique ID and a contextCSN for each replicated master exists. A valid serverID is a integer value from 0 to 4095 (limited to 3 hex digits, example: '12' compares the contextCSN matching '#00C#')",
    default=False
)

parser.add_argument(
    "-T", "--starttls",
    dest="starttls",
    action="store_true",
    help="Start TLS on LDAP provider/consumers connections",
    default=False
)

parser.add_argument(
    "-D", "--dn",
    dest="dn",
    action="store",
    type=str,
    help="LDAP bind DN (example: uid=nagios,ou=sysaccounts,o=example"
)

parser.add_argument(
    "-P", "--pwd",
    dest="pwd",
    action="store",
    type=str,
    help="LDAP bind password",
    default=None
)

parser.add_argument(
    "-b", "--basedn",
    dest="basedn",
    action="store",
    type=str,
    help="LDAP base DN (example: o=example)"
)

parser.add_argument(
    "-f", "--filter",
    dest="filterstr",
    action="store",
    type=str,
    help="LDAP filter (default: (objectClass=*))",
    default='(objectClass=*)'
)

parser.add_argument(
    "-d", "--debug",
    dest="debug",
    action="store_true",
    help="Debug mode",
    default=False
)

parser.add_argument(
    "-n", "--nagios",
    dest="nagios",
    action="store_true",
    help="Nagios check plugin mode",
    default=False
)

parser.add_argument(
    "-q", "--quiet",
    dest="quiet",
    action="store_true",
    help="Quiet mode",
    default=False
)

parser.add_argument(
    "--no-check-certificate",
    dest="nocheckcert",
    action="store_true",
    help="Don't check the server certificate (Default: False)",
    default=False
)

parser.add_argument(
    "--no-check-contextCSN",
    dest="nocheckcontextcsn",
    action="store_true",
    help="Don't check servers contextCSN (Default: False)",
    default=False
)

parser.add_argument(
    "-a", "--attributes",
    dest="attrs",
    action="store_true",
    help="Check attributes values (Default: check only entryCSN)",
    default=False
)

parser.add_argument(
    "--exclude-attributes",
    dest="excl_attrs",
    action="store",
    type=str,
    help="Don't check this attribut (only in attribute check mode)",
    default=None
)

parser.add_argument(
    "--touch",
    dest="touch",
    action="store",
    type=str,
    help="Touch attribute giving in parameter to force resync a this LDAP object from provider. A value '%s' will be add to this attribute and remove after. The user use to connect to the LDAP directory must have write permission on this attribute on each object." % TOUCH_VALUE,
    default=None
)

parser.add_argument(
    "--replace-touch",
    dest="replacetouch",
    action="store_true",
    help="In touch mode, replace value instead of adding.",
    default=False
)

parser.add_argument(
    "--remove-touch-value",
    dest="removetouchvalue",
    action="store_true",
    help="In touch mode, remove touch value if present.",
    default=False
)

parser.add_argument(
    "--page-size",
    dest="page_size",
    action="store",
    type=int,
    help="Page size: if defined, paging control using LDAP v3 extended control will be enabled.",
    default=None
)

options = parser.parse_args()

if not options.provider or not options.consumer:
    print "You must provide provider and customer URI"
    if options.nagios:
        sys.exit(3)
    sys.exit(1)

if not options.basedn:
    print "You must provide base DN of connection to LDAP servers"
    if options.nagios:
        sys.exit(3)
    sys.exit(1)

if not 0 <= options.serverid <= 4095:
    print "ServerID should be a integer value from 0 to 4095 (limited to 3 hexadecimal digits)."
    if options.nagios:
        sys.exit(3)
    sys.exit(1)

if options.touch and not options.attrs:
    logging.info('Force option attrs on touch mode')
    options.attrs = True

if options.dn and options.pwd is None:
    options.pwd = getpass.getpass()

excl_attrs = []
if options.excl_attrs:
    for ex in options.excl_attrs.split(','):
        excl_attrs.append(ex.strip())

FORMAT = "%(asctime)s - %(levelname)s: %(message)s"

if options.debug:
    logging.basicConfig(level=logging.DEBUG, format=FORMAT)
    ldap.set_option(ldap.OPT_DEBUG_LEVEL, 0)  # pylint: disable=no-member
    ldapmodule_trace_level = 1
    ldapmodule_trace_file = sys.stderr
elif options.nagios:
    logging.basicConfig(level=logging.ERROR, format=FORMAT)
elif options.quiet:
    logging.basicConfig(level=logging.WARNING, format=FORMAT)
else:
    logging.basicConfig(level=logging.INFO, format=FORMAT)

class LdapServer(object):

    uri = ""
    dn = ""
    pwd = ""
    start_tls = False

    con = 0

    def __init__(self, uri, dn, pwd, start_tls=False, page_size=None):
        self.uri = uri
        self.dn = dn
        self.pwd = pwd
        self.start_tls = start_tls
        self.page_size = page_size

    def connect(self):
        if self.con == 0:
            try:
                con = ldap.initialize(self.uri)
                con.protocol_version = ldap.VERSION3  # pylint: disable=no-member
                if self.start_tls:
                    con.start_tls_s()
                if self.dn:
                    con.simple_bind_s(self.dn, self.pwd)
                self.con = con
            except LDAPError:
                logging.error("LDAP Error", exc_info=True)
                return False
        return True

    def getContextCSN(self, basedn=False, serverid=False):
        if not basedn:
            basedn = self.dn
        data = self.search(basedn, '(objectclass=*)', ['contextCSN'])
        if data:
            contextCSNs = data[0][0][1]['contextCSN']
            logging.debug('Found contextCSNs %s', contextCSNs)
            if serverid is False:
                return contextCSNs[0]
            csnid = str(format(serverid, 'X')).zfill(3)
            sub = '#%s#' % csnid
            CSN = [s for s in contextCSNs if sub in s]
            if not CSN:
                logging.error(
                    "No contextCSN matching with ServerID %s (=%s) could be found.",
                    serverid, sub
                )
                return False
            return CSN[0]
        return False

    def search(self, basedn, filterstr, attrs):
        if self.page_size:
            return self.paged_search(basedn, filterstr, attrs)
        res_id = self.con.search(basedn, ldap.SCOPE_SUBTREE, filterstr, attrs)  # pylint: disable=no-member
        ret = []
        while 1:
            res_type, res_data = self.con.result(res_id, 0)
            if res_data == []:
                break
            else:
                if res_type == ldap.RES_SEARCH_ENTRY:  # pylint: disable=no-member
                    ret.append(res_data)
        return ret

    def paged_search(self, basedn, filterstr, attrs):
        ret = []
        page = 0
        pg_ctrl = SimplePagedResultsControl(True, self.page_size, '')
        while page == 0 or pg_ctrl.cookie:
            page += 1
            logging.debug('Page search: loading page %d', page)
            res_id = self.con.search_ext(
                basedn, ldap.SCOPE_SUBTREE,  # pylint: disable=no-member
                filterstr, attrs,
                serverctrls=[pg_ctrl]
            )
            res_type, res_data, res_id, serverctrls = self.con.result3(res_id)  # pylint: disable=unused-variable
            for serverctrl in serverctrls:
                if serverctrl.controlType == SimplePagedResultsControl.controlType:
                    pg_ctrl.cookie = serverctrl.cookie
                    break
            for item in res_data:
                ret.append([item])
        return ret

    def update_object(self, dn, old, new):
        ldif = modlist.modifyModlist(old, new)
        if ldif == []:
            return True
        try:
            logging.debug('Update object %s: %s', dn, ldif)
            self.con.modify_s(dn, ldif)
            return True
        except LDAPError:
            logging.error('Error updating object %s', dn, exc_info=True)
        return False

    @staticmethod
    def get_attr(obj, attr):
        if attr in obj[0][1]:
            return obj[0][1][attr]
        return []

    def touch_object(self, dn, attr, orig_value):
        old = {}
        if orig_value:
            old[attr] = orig_value
        new = {}

        if options.replacetouch:
            if not orig_value or TOUCH_VALUE not in orig_value:
                new[attr] = [TOUCH_VALUE]
        else:
            new[attr] = list(orig_value)
            if orig_value or TOUCH_VALUE in orig_value:
                new[attr].remove(TOUCH_VALUE)
            else:
                new[attr].append(TOUCH_VALUE)
        try:
            logging.info(
                'Touch object "%s" on attribute "%s": %s => %s',
                dn, attr, old, new
            )
            if self.update_object(dn, old, new):
                logging.info('Restore original value of attribute "%s" of object "%s"', attr, dn)
                if options.removetouchvalue and TOUCH_VALUE in old[attr]:
                    old[attr].remove(TOUCH_VALUE)
                self.update_object(dn, new, old)
                return True
        except LDAPError:
            logging.error('Error touching object "%s"', dn, exc_info=True)
        return False

if options.nocheckcert:
    ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_NEVER)  # pylint: disable=no-member

servers = [options.provider, options.consumer]

LdapServers = {}
LdapObjects = {}
LdapServersCSN = {}

for srv in servers:
    logging.info('Connect to %s', srv)
    LdapServers[srv] = LdapServer(srv, options.dn, options.pwd, options.starttls, page_size=options.page_size)

    if not LdapServers[srv].connect():
        if options.nagios:
            print "UNKWNON - Failed to connect to %s" % srv
            sys.exit(3)
        else:
            sys.exit(1)

    if not options.nocheckcontextcsn:
        LdapServersCSN[srv] = LdapServers[srv].getContextCSN(options.basedn, options.serverid)
        logging.info('ContextCSN of %s: %s', srv, LdapServersCSN[srv])

    logging.info('List objects from %s', srv)
    LdapObjects[srv] = {}

    if options.attrs:
        for obj in LdapServers[srv].search(options.basedn, options.filterstr, []):
            logging.debug('Found on %s: %s', srv, obj[0][0])
            LdapObjects[srv][obj[0][0]] = obj[0][1]
    else:
        for obj in LdapServers[srv].search(options.basedn, options.filterstr, ['entryCSN']):
            logging.debug(
                'Found on %s: %s / %s',
                srv, obj[0][0], obj[0][1]['entryCSN'][0]
            )
            LdapObjects[srv][obj[0][0]] = obj[0][1]['entryCSN'][0]

    logging.info('%s objects founds', len(LdapObjects[srv]))


not_found = {}
not_sync = {}

for srv in servers:
    not_found[srv] = []
    not_sync[srv] = []

if options.attrs:
    logging.info("Check if objects a are synchronized (by comparing attributes's values)")
else:
    logging.info('Check if objets are synchronized (by comparing entryCSN)')
for obj in LdapObjects[options.provider]:
    logging.debug('Check obj %s', obj)
    for srv in LdapObjects:
        if srv == options.provider:
            continue
        if obj in LdapObjects[srv]:
            touch = False
            if LdapObjects[options.provider][obj] != LdapObjects[srv][obj]:
                if options.attrs:
                    attrs_list = []
                    for attr in LdapObjects[options.provider][obj]:
                        if attr in excl_attrs:
                            continue
                        if attr not in LdapObjects[srv][obj]:
                            attrs_list.append(attr)
                            logging.debug(
                                "Obj %s not synchronized: %s not present on %s",
                                obj, ','.join(attrs_list), srv
                            )
                            touch = True
                        else:
                            LdapObjects[srv][obj][attr].sort()
                            LdapObjects[options.provider][obj][attr].sort()
                            if LdapObjects[srv][obj][attr] != LdapObjects[options.provider][obj][attr]:
                                attrs_list.append(attr)
                                logging.debug(
                                    "Obj %s not synchronized: %s not same value(s)",
                                    obj, ','.join(attrs_list)
                                )
                                touch = True
                    if attrs_list:
                        not_sync[srv].append("%s (%s)" % (obj, ','.join(attrs_list)))
                else:
                    logging.debug(
                        "Obj %s not synchronized: %s <-> %s",
                        obj, LdapObjects[options.provider][obj], LdapObjects[srv][obj]
                    )
                    not_sync[srv].append(obj)
            if touch and options.touch:
                orig_value = []
                if options.touch in LdapObjects[options.provider][obj]:
                    orig_value = LdapObjects[options.provider][obj][options.touch]
                LdapServers[options.provider].touch_object(obj, options.touch, orig_value)
        else:
            logging.debug('Obj %s: not found on %s', obj, srv)
            not_found[srv].append(obj)
            if options.touch:
                orig_value = []
                if options.touch in LdapObjects[options.provider][obj]:
                    orig_value = LdapObjects[options.provider][obj][options.touch]
                LdapServers[options.provider].touch_object(obj, options.touch, orig_value)

for obj in LdapObjects[options.consumer]:
    logging.debug('Check obj %s of consumer', obj)
    if obj not in LdapObjects[options.provider]:
        logging.debug('Obj %s: not found on provider', obj)
        not_found[options.provider].append(obj)

if options.nagios:
    errors = []
    long_output = []

    if not options.nocheckcontextcsn:
        if not LdapServersCSN[options.provider]:
            errors.append('ContextCSN of LDAP server provider could not be found')
        else:
            long_output.append('ContextCSN on LDAP server provider = %s' % LdapServersCSN[options.provider])
            for srv in LdapServersCSN:
                if srv == options.provider:
                    continue
                if not LdapServersCSN[srv]:
                    errors.append('ContextCSN of %s not found' % srv)
                elif LdapServersCSN[srv] != LdapServersCSN[options.provider]:
                    errors.append('ContextCSN of %s not the same of provider' % srv)
                    long_output.append('ContextCSN on LDAP server %s = %s' % (srv, LdapServersCSN[srv]))

    if not_found[options.consumer]:
        errors.append("%s not found object(s) on consumer" % len(not_found[options.consumer]))
        long_output.append("Object(s) not found on server %s (consumer) :" % options.consumer)
        for obj in not_found[options.consumer]:
            long_output.append(" - %s" % obj)
    if not_found[options.provider]:
        errors.append("%s not found object(s) on provider" % len(not_found[options.provider]))
        long_output.append("Object(s) not found on server %s (provider) :" % options.provider)
        for obj in not_found[options.provider]:
            long_output.append(" - %s" % obj)
    if not_sync[options.consumer]:
        errors.append("%s not synchronized object(s) on consumer" % len(not_sync[options.consumer]))
        long_output.append("Object(s) not synchronized on server %s (consumer) :" % options.consumer)
        for obj in not_sync[options.consumer]:
            long_output.append(" - %s" % obj)
    if errors:
        print "CRITICAL: " + ', '.join(errors) + "\n\n" + "\n".join(long_output)
        sys.exit(2)
    else:
        print 'OK: consumer and provider are synchronized'
        sys.exit(0)
else:
    noerror = True
    for srv in servers:
        if not options.nocheckcontextcsn:
            if not LdapServersCSN[options.provider]:
                logging.warning('ContextCSN of LDAP server provider could not be found')
                noerror = False
            else:
                for srv in LdapServersCSN:
                    if srv == options.provider:
                        continue
                    if not LdapServersCSN[srv]:
                        logging.warning('ContextCSN of %s not found', srv)
                        noerror = False
                    elif LdapServersCSN[srv] != LdapServersCSN[options.provider]:
                        logging.warning('ContextCSN of %s not the same of provider', srv)
                        noerror = False

        if not_found[srv]:
            logging.warning(
                'Not found objects on %s :\n  - %s',
                srv, '\n  - '.join(not_found[srv])
            )
            noerror = False
        if not_sync[srv]:
            logging.warning(
                'Not sync objects on %s: %s',
                srv, '\n  - '.join(not_sync[srv])
            )
            noerror = False

    if noerror:
        logging.info('No sync problem detected')