#! /usr/bin/python -E
# Authors: Karl MacMillan <kmacmillan@mentalrootkit.com>
#
# Copyright (C) 2007  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
import sys
import os

import getpass, ldap, re, krbV
import traceback, logging

from ipapython import ipautil
from ipaserver.install import replication, dsinstance, installutils
from ipaserver.install import bindinstance
from ipaserver import ipaldap
from ipapython import version
from ipalib import api, errors, util

CACERT = "/etc/ipa/ca.crt"

# dict of command name and tuples of min/max num of args needed
commands = {
    "list":(0, 1, "[master fqdn]", ""),
    "connect":(1, 2, "<master fqdn> [other master fqdn]",
                    "must provide the name of the servers to connect"),
    "disconnect":(1, 2, "<master fqdn> [other master fqdn]",
                    "must provide the name of the server to disconnect"),
    "del":(1, 1, "<master fqdn>",
                    "must provide hostname of master to delete"),
    "re-initialize":(0, 0, "", ""),
    "force-sync":(0, 0, "", "")
}

def parse_options():
    from optparse import OptionParser

    parser = OptionParser(version=version.VERSION)
    parser.add_option("-H", "--host", dest="host", help="starting host")
    parser.add_option("-p", "--password", dest="dirman_passwd", help="Directory Manager password")
    parser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
                      help="provide additional information")
    parser.add_option("-f", "--force", dest="force", action="store_true", default=False,
                      help="ignore some types of errors")
    parser.add_option("--binddn", dest="binddn", default=None,
                      help="Bind DN to use with remote server")
    parser.add_option("--bindpw", dest="bindpw", default=None,
                      help="Password for Bind DN to use with remote server")
    parser.add_option("--winsync", dest="winsync", action="store_true", default=False,
                      help="This is a Windows Sync Agreement")
    parser.add_option("--cacert", dest="cacert", default=None,
                      help="Full path and filename of CA certificate to use with TLS/SSL to the remote server")
    parser.add_option("--win-subtree", dest="win_subtree", default=None,
                      help="DN of Windows subtree containing the users you want to sync (default cn=Users,<domain suffix)")
    parser.add_option("--passsync", dest="passsync", default=None,
                      help="Password for the Windows PassSync user")
    parser.add_option("--from", dest="fromhost", help="Host to get data from")

    options, args = parser.parse_args()

    valid_syntax = False

    if len(args):
        n = len(args) - 1
        k = commands.keys()
        for cmd in k:
            if cmd == args[0]:
                v = commands[cmd]
                err = None
                if n < v[0]:
                    err = v[3]
                elif n > v[1]:
                    err = "too many arguments"
                else:
                    valid_syntax = True
                if err:
                    parser.error("Invalid syntax: %s\nUsage: %s [options] %s" % (err, cmd, v[2]))

    if not valid_syntax:
        cmdstr = " | ".join(commands.keys())
        parser.error("must provide a command [%s]" % cmdstr)

    # set log level
    if options.verbose:
        # if verbose, output events at INFO level if not already
        mylogger = logging.getLogger()
        if mylogger.getEffectiveLevel() > logging.INFO:
            mylogger.setLevel(logging.INFO)
        # else user has already configured logging externally lower
    return options, args

def test_connection(realm, host):
    """
    Make a GSSAPI connection to the remote LDAP server to test out credentials.

    This is used so we can fall back to promping for the DM password.

    returns True if connection successful, False otherwise
    """
    try:
        replman = replication.ReplicationManager(realm, host, None)
        ents = replman.find_replication_agreements()
        del replman
        return True
    except ldap.LOCAL_ERROR:
        return False

def list_replicas(realm, host, replica, dirman_passwd, verbose):

    is_replica = False
    winsync_peer = None
    peers = {}

    try:
        conn = ipaldap.IPAdmin(host, 636, cacert=CACERT)
        if dirman_passwd:
            conn.do_simple_bind(bindpw=dirman_passwd)
        else:
            conn.do_sasl_gssapi_bind()

        dn = 'cn=masters,cn=ipa,cn=etc,%s' % util.realm_to_suffix(realm)
        entries = conn.search_s(dn, ldap.SCOPE_ONELEVEL)

        for ent in entries:
            peers[ent.cn] = ['master', '']

        dn = 'cn=replicas,cn=ipa,cn=etc,%s' % util.realm_to_suffix(realm)
        entries = conn.search_s(dn, ldap.SCOPE_ONELEVEL)

        for ent in entries:
            peers[ent.cn] = ent.ipaconfigstring.split(':')

    except Exception, e:
        print "Failed to get data from '%s': %s" % (host, str(e))
        return


    if not replica:
        for k, p in peers.iteritems():
            print '%s: %s' % (k, p[0])
        return

    # ok we are being ask for info about a specific replica
    for k, p in peers.iteritems():
        if replica == k:
            is_replica = True
            if p[0] == 'winsync':
                winsync_peer = p[1]

    if not is_replica:
        print "Cannot find %s in public server list" % replica
        return

    try:
        if winsync_peer:
            repl = replication.ReplicationManager(realm, winsync_peer,
                                                  dirman_passwd)
            cn, dn = repl.agreement_dn(replica)
            entries = repl.conn.search_s(dn, ldap.SCOPE_BASE,
                                         "(objectclass=nsDSWindowsReplicationAgreement)")
            ent_type = 'winsync'
        else:
            repl = replication.ReplicationManager(realm, replica,
                                                  dirman_passwd)
            entries = repl.find_replication_agreements()
            ent_type = 'replica'
    except Exception, e:
        print "Failed to get data from '%s': %s" % (replica, str(e))
        return

    for entry in entries:
        print '%s: %s' % (entry.nsds5replicahost, ent_type)

        if verbose:
            print "  last init status: %s" % entry.nsds5replicalastinitstatus
            print "  last init ended: %s" % str(ipautil.parse_generalized_time(entry.nsds5replicalastinitend))
            print "  last update status: %s" % entry.nsds5replicalastupdatestatus
            print "  last update ended: %s" % str(ipautil.parse_generalized_time(entry.nsds5replicalastupdateend))

def del_link(realm, replica1, replica2, dirman_passwd, force=False):

    repl2 = None

    try:
        repl1 = replication.ReplicationManager(realm, replica1, dirman_passwd)

        type1 = repl1.get_agreement_type(replica2)

        repl_list = repl1.find_ipa_replication_agreements()
        if not force and len(repl_list) <= 1 and type1 == replication.IPA_REPLICA:
            print "Cannot remove the last replication link of '%s'" % replica1
            print "Please use the 'del' command to remove it from the domain"
            return

    except ldap.NO_SUCH_OBJECT:
        print "'%s' has no replication agreement for '%s'" % (replica1, replica2)
        return
    except errors.NotFound:
        print "'%s' has no replication agreement for '%s'" % (replica1, replica2)
        return
    except Exception, e:
        print "Failed to get data from '%s': %s" % (replica1, str(e))
        return

    if type1 == replication.IPA_REPLICA:
        try:
            repl2 = replication.ReplicationManager(realm, replica2, dirman_passwd)

            repl_list = repl1.find_ipa_replication_agreements()
            if not force and len(repl_list) <= 1:
                print "Cannot remove the last replication link of '%s'" % replica2
                print "Please use the 'del' command to remove it from the domain"
                return

        except ldap.NO_SUCH_OBJECT:
            print "'%s' has no replication agreement for '%s'" % (replica2, replica1)
            if not force:
                return
        except errors.NotFound:
            print "'%s' has no replication agreement for '%s'" % (replica2, replica1)
            if not force:
                return
        except Exception, e:
            print "Failed to get data from '%s': %s" % (replica2, str(e))
            if not force:
                return

    if repl2 and type1 == replication.IPA_REPLICA:
        failed = False
        try:
            repl2.delete_agreement(replica1)
            repl2.delete_referral(replica1)
        except ldap.LDAPError, e:
            desc = e.args[0]['desc'].strip()
            info = e.args[0].get('info', '').strip()
            print "Unable to remove agreement on %s: %s: %s" % (replica2, desc, info)
            failed = True
        except Exception, e:
            print "Unable to remove agreement on %s: %s" % (replica2, str(e))
            failed = True

        if failed:
            if force:
                print "Forcing removal on '%s'" % replica1
            else:
                return

    if not repl2 and force:
        print "Forcing removal on '%s'" % replica1

    repl1.delete_agreement(replica2)
    repl1.delete_referral(replica2)

    if type1 == replication.WINSYNC:
        try:
            dn = 'cn=%s,cn=replicas,cn=ipa,cn=etc,%s' % (replica2,
                                                         util.realm_to_suffix(realm))
            entries = repl1.conn.search_s(dn, ldap.SCOPE_SUBTREE)
            if len(entries) != 0:
                dnset = repl1.conn.get_dns_sorted_by_length(entries,
                                                            reverse=True)
                for dns in dnset:
                    for dn in dns:
                        repl1.conn.deleteEntry(dn)
        except Exception, e:
            print "Error deleting winsync replica shared info: %s" % str(e)


def del_master(realm, hostname, options):

    force_del = False

    # 1. Connect to the master to be removed.
    try:
        delrepl = replication.ReplicationManager(realm, hostname, options.dirman_passwd)
    except Exception, e:
        if not options.force:
            print "Unable to delete replica %s: %s" % (hostname, str(e))
            sys.exit(1)
        else:
            print "Unable to connect to replica %s, forcing removal" % hostname
            force_del = True

    # 2. Connect to the local server
    try:
        thisrepl = replication.ReplicationManager(realm, options.host,
                                                  options.dirman_passwd)
    except Exception, e:
        print "Failed to connect to server %s: %s" % (options.host, str(e))
        sys.exit(1)

    if force_del:
        dn = 'cn=masters,cn=ipa,cn=etc,%s' % thisrepl.suffix
        res = thisrepl.conn.search_s(dn, ldap.SCOPE_ONELEVEL)
        replica_names = []
        for entry in res:
            replica_names.append(entry.cn)
    else:
        # 2. Get list of agreements.
        replica_names = delrepl.find_ipa_replication_agreements()

    # 3. Remove each agreement
    for r in replica_names:
        try:
            del_link(realm, r, hostname, options.dirman_passwd, force=True)
        except Exception, e:
            print "There were issues removing a connection: %s" % str(e)

    # 4. Finally clean up the removed replica common entries.
    try:
        thisrepl.replica_cleanup(hostname, realm, force=True)
    except Exception, e:
        print "Failed to cleanup %s entries: %s" % (hostname, str(e))
        print "You may need to manually remove them from the tree"

    # 5. And clean up the removed replica DNS entries if any.
    try:
        if bindinstance.dns_container_exists(options.host, thisrepl.suffix):
            if options.dirman_passwd:
                api.Backend.ldap2.connect(bind_dn='cn=Directory Manager',
                                          bind_pw=options.dirman_passwd)
            else:
                ccache = krbV.default_context().default_ccache().name
                api.Backend.ldap2.connect(ccache=ccache)
            bind = bindinstance.BindInstance()
            bind.remove_master_dns_records(hostname, realm, realm.lower())
    except Exception, e:
        print "Failed to cleanup %s DNS entries: %s" % (hostname, str(e))
        print "You may need to manually remove them from the tree"

def add_link(realm, replica1, replica2, dirman_passwd, options):

    if options.winsync:
        if not options.binddn or not options.bindpw or not options.cacert or not options.passsync:
            logging.error("The arguments --binddn, --bindpw, --passsync and --cacert are required to create a winsync agreement")
            sys.exit(1)

    if options.cacert:
        # have to install the given CA cert before doing anything else
        ds = dsinstance.DsInstance(realm_name = realm,
                                   dm_password = dirman_passwd)
        if not ds.add_ca_cert(options.cacert):
            print "Could not load the required CA certificate file [%s]" % options.cacert
            return
        else:
            print "Added CA certificate %s to certificate database for %s" % (options.cacert, replica1)

    # need to wait until cacert is installed as that command may restart
    # the directory server and kill the connection
    try:
        repl1 = replication.ReplicationManager(realm, replica1, dirman_passwd)

    except ldap.NO_SUCH_OBJECT:
        print "Cannot find replica '%s'" % replica1
        return
    except errors.NotFound:
        print "Cannot find replica '%s'" % replica1
        return
    except Exception, e:
        print "Failed to get data from '%s': %s" % (replica1, str(e))
        return

    if options.winsync:
        repl1.setup_winsync_replication(replica2,
                                        options.binddn, options.bindpw,
                                        options.passsync, options.win_subtree,
                                        options.cacert)
    else:
        repl1.setup_gssapi_replication(replica2, "cn=Directory Manager", dirman_passwd)
    print "Connected '%s' to '%s'" % (replica1, replica2)

def re_initialize(realm, options):

    if not options.fromhost:
        print "re-initialize requires the option --from <host name>"
        sys.exit(1)

    repl = replication.ReplicationManager(realm, options.fromhost, options.dirman_passwd)

    thishost = installutils.get_fqdn()

    filter = "(&(nsDS5ReplicaHost=%s)(|(objectclass=nsDSWindowsReplicationAgreement)(objectclass=nsds5ReplicationAgreement)))" % thishost
    entry = repl.conn.search_s("cn=config", ldap.SCOPE_SUBTREE, filter)
    if len(entry) == 0:
        logging.error("Unable to find %s -> %s replication agreement" % (options.fromhost, thishost))
        sys.exit(1)
    if len(entry) > 1:
        logging.error("Found multiple agreements for %s. Only initializing the first one returned: %s" % (thishost, entry[0].dn))

    repl.initialize_replication(entry[0].dn, repl.conn)
    repl.wait_for_repl_init(repl.conn, entry[0].dn)

    ds = dsinstance.DsInstance(realm_name = realm, dm_password = options.dirman_passwd)
    ds.init_memberof()

def force_sync(realm, thishost, fromhost, dirman_passwd):

    repl = replication.ReplicationManager(realm, fromhost, dirman_passwd)
    repl.force_sync(repl.conn, thishost)

def main():
    if os.getegid() == 0:
        installutils.check_server_configuration()
    elif not os.path.exists('/etc/ipa/default.conf'):
        sys.exit("IPA is not configured on this system.")

    options, args = parse_options()

    # Just initialize the environment. This is so the installer can have
    # access to the plugin environment
    api_env = {}
    api_env['in_server'] = True

    if os.getegid() != 0:
        api_env['log'] = None # turn off logging for non-root

    api.bootstrap(**api_env)
    api.finalize()

    dirman_passwd = None
    realm = krbV.default_context().default_realm

    if options.host:
        host = options.host
    else:
        host = installutils.get_fqdn()

    options.host = host

    if options.dirman_passwd:
        dirman_passwd = options.dirman_passwd
    else:
        if not test_connection(realm, host):
            dirman_passwd = getpass.getpass("Directory Manager password: ")

    options.dirman_passwd = dirman_passwd

    if args[0] == "list":
        replica = None
        if len(args) == 2:
            replica = args[1]
        list_replicas(realm, host, replica, dirman_passwd, options.verbose)
    elif args[0] == "del":
        del_master(realm, args[1], options)
    elif args[0] == "re-initialize":
        re_initialize(realm, options)
    elif args[0] == "force-sync":
        if not options.fromhost:
            print "force-sync requires the option --from <host name>"
            sys.exit(1)
        force_sync(realm, host, options.fromhost, options.dirman_passwd)
    elif args[0] == "connect":
        if len(args) == 3:
            replica1 = args[1]
            replica2 = args[2]
        elif len(args) == 2:
            replica1 = host
            replica2 = args[1]
        add_link(realm, replica1, replica2, dirman_passwd, options)
    elif args[0] == "disconnect":
        if len(args) == 3:
            replica1 = args[1]
            replica2 = args[2]
        elif len(args) == 2:
            replica1 = host
            replica2 = args[1]
        del_link(realm, replica1, replica2, dirman_passwd)

try:
    main()
except KeyboardInterrupt:
    sys.exit(1)
except SystemExit, e:
    sys.exit(e)
except RuntimeError, e:
    sys.exit(e)
except ldap.INVALID_CREDENTIALS:
    print "Invalid password"
    sys.exit(1)
except ldap.INSUFFICIENT_ACCESS:
    print "Insufficient access"
    sys.exit(1)
except ldap.LOCAL_ERROR, e:
    print e.args[0]['info']
    sys.exit(1)
except ldap.SERVER_DOWN, e:
    print e.args[0]['desc']
except Exception, e:
    print "unexpected error: %s" % str(e)
    sys.exit(1)