#!/usr/bin/python2.6

# Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

#

#    Licensed under the Apache License, Version 2.0 (the "License"); you may

#    not use this file except in compliance with the License. You may obtain

#    a copy of the License at

#

#         http://www.apache.org/licenses/LICENSE-2.0

#

#    Unless required by applicable law or agreed to in writing, software

#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the

#    License for the specific language governing permissions and limitations

#    under the License.

import os

import re

import sys

import netaddr

import smf_include

from subprocess import CalledProcessError, Popen, PIPE, check_call

def start():

    # verify paths are valid

    for f in sys.argv[2:4]:

        if not os.path.exists(f) or not os.access(f, os.R_OK):

            print '%s does not exist or is not readable' % f

            return smf_include.SMF_EXIT_ERR_CONFIG

    # System-wide forwarding (either ipv4 or ipv6 or both) must be enabled

    # before neutron-l3-agent can be started.

    cmd = ["/usr/sbin/ipadm", "show-prop", "-c", "-p", "forwarding",

           "-o", "current", "ipv4"]

    p = Popen(cmd, stdout=PIPE, stderr=PIPE)

    output, error = p.communicate()

    if p.returncode != 0:

        print "failed to determine if IPv4 forwarding is enabled or not"

        return smf_include.SMF_EXIT_ERR_FATAL

    v4fwding = "on" in output

    cmd = ["/usr/sbin/ipadm", "show-prop", "-c", "-p", "forwarding",

           "-o", "current", "ipv6"]

    p = Popen(cmd, stdout=PIPE, stderr=PIPE)

    output, error = p.communicate()

    if p.returncode != 0:

        print "failed to determine if IPv6 forwarding is enabled or not"

        return smf_include.SMF_EXIT_ERR_FATAL

    v6fwding = "on" in output

    if not any((v4fwding, v6fwding)):

        print "System-wide IPv4 or IPv6 (or both) forwarding must be " \

              "enabled before enabling neutron-l3-agent"

        return smf_include.SMF_EXIT_ERR_CONFIG

    cmd = "/usr/lib/neutron/neutron-l3-agent --config-file %s " \

        "--config-file %s" % tuple(sys.argv[2:4])

    smf_include.smf_subprocess(cmd)

def stop():

    try:

        # first kill the SMF contract

        check_call(["/usr/bin/pkill", "-c", sys.argv[2]])

    except CalledProcessError as err:

        print "failed to kill the SMF contract: %s" % (err)

        return smf_include.SMF_EXIT_ERR_FATAL

    # remove VNICs associated with L3 agent

    cmd = ["/usr/sbin/ipadm", "show-if", "-p", "-o", "ifname"]

    p = Popen(cmd, stdout=PIPE, stderr=PIPE)

    output, error = p.communicate()

    if p.returncode != 0:

        print "failed to retrieve IP interface names"

        return smf_include.SMF_EXIT_ERR_CONFIG

    ifnames = output.splitlines()

    # L3 agent datalinks are always 15 characters in length. They start

    # with either 'l3i' or 'l3e', end with '_0', and in between they are

    # hexadecimal digits.

    prog = re.compile('l3[ie][0-9A-Fa-f\_]{10}_0')

    for ifname in ifnames:

        if not prog.search(ifname):

            continue

        try:

            # first remove the IP

            check_call(["/usr/bin/pfexec", "/usr/sbin/ipadm", "delete-ip",

                        ifname])

            # next remove the VNIC

            check_call(["/usr/bin/pfexec", "/usr/sbin/dladm", "delete-vnic",

                        ifname])

        except CalledProcessError as err:

            print "failed to remove datalinks used by L3 agent: %s" % (err)

            return smf_include.SMF_EXIT_ERR_FATAL

    # remove IP NAT rules added by neutron-l3-agent

    cmd = ["/usr/bin/pfexec", "/usr/sbin/ipnat", "-lR"]

    p = Popen(cmd, stdout=PIPE, stderr=PIPE)

    output, error = p.communicate()

    if p.returncode != 0:

        print "failed to retrieve IP NAT rules"

        return smf_include.SMF_EXIT_ERR_FATAL

    ipnat_rules = output.splitlines()

    # L3 agent IP NAT rules are of the form

    # bimap l3e64ccc496_a_0 192.168.1.3/32 -> 172.16.10.3/32

    prog = re.compile('l3e[0-9A-Fa-f\_]{10}_0')

    for ipnat_rule in ipnat_rules:

        if not prog.search(ipnat_rule):

            continue

        # remove the IP NAT rule

        try:

            p = Popen(["echo", ipnat_rule], stdout=PIPE)

            check_call(["/usr/bin/pfexec", "/usr/sbin/ipnat", "-r", "-f", "-"],

                       stdin=p.stdout)

        except CalledProcessError as err:

            print "failed to remove IP NAT rule %s: %s" % (ipnat_rule, err)

            return smf_include.SMF_EXIT_ERR_FATAL

    return smf_include.SMF_EXIT_OK

if __name__ == "__main__":

    os.putenv("LC_ALL", "C")

    smf_include.smf_main()