summaryrefslogtreecommitdiff
path: root/src/conf_mode/service_mdns-repeater.py
blob: a2c90b5375834639ee0f4793f61b107b0c9a8802 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
#!/usr/bin/env python3
#
# Copyright (C) 2017-2022 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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 os

from json import loads
from sys import exit
from netifaces import ifaddresses, interfaces, AF_INET

from vyos.config import Config
from vyos.ifconfig.vrrp import VRRP
from vyos.template import render
from vyos.utils.process import call
from vyos import ConfigError
from vyos import airbag
airbag.enable()

config_file = '/run/avahi-daemon/avahi-daemon.conf'
vrrp_running_file = '/run/mdns_vrrp_active'

def get_config(config=None):
    if config:
        conf = config
    else:
        conf = Config()
    base = ['service', 'mdns', 'repeater']
    mdns = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)

    if mdns:
        mdns['vrrp_exists'] = conf.exists('high-availability vrrp')
    return mdns

def verify(mdns):
    if not mdns:
        return None

    if 'disable' in mdns:
        return None

    # We need at least two interfaces to repeat mDNS advertisments
    if 'interface' not in mdns or len(mdns['interface']) < 2:
        raise ConfigError('mDNS repeater requires at least 2 configured interfaces!')

    # For mdns-repeater to work it is essential that the interfaces has
    # an IPv4 address assigned
    for interface in mdns['interface']:
        if interface not in interfaces():
            raise ConfigError(f'Interface "{interface}" does not exist!')

        if AF_INET not in ifaddresses(interface):
            raise ConfigError('mDNS repeater requires an IPv4 address to be '
                                  f'configured on interface "{interface}"')

    return None

# Get VRRP states from interfaces, returns only interfaces where state is MASTER
def get_vrrp_master(interfaces):
    json_data = loads(VRRP.collect('json'))
    for group in json_data:
        if 'data' in group:
            if 'ifp_ifname' in group['data']:
                iface = group['data']['ifp_ifname']
                state = group['data']['state'] # 2 = Master
                if iface in interfaces and state != 2:
                    interfaces.remove(iface)
    return interfaces

def generate(mdns):
    if not mdns:
        return None

    if 'disable' in mdns:
        print('Warning: mDNS repeater will be deactivated because it is disabled')
        return None

    if mdns['vrrp_exists'] and 'vrrp_disable' in mdns:
        mdns['interface'] = get_vrrp_master(mdns['interface'])

        if len(mdns['interface']) < 2:
            return None

    render(config_file, 'mdns-repeater/avahi-daemon.j2', mdns)
    return None

def apply(mdns):
    if not mdns or 'disable' in mdns:
        call('systemctl stop avahi-daemon.service')
        if os.path.exists(config_file):
            os.unlink(config_file)

        if os.path.exists(vrrp_running_file):
            os.unlink(vrrp_running_file)
    else:
        if 'vrrp_disable' not in mdns and os.path.exists(vrrp_running_file):
            os.unlink(vrrp_running_file)

        if mdns['vrrp_exists'] and 'vrrp_disable' in mdns:
            if not os.path.exists(vrrp_running_file):
                os.mknod(vrrp_running_file) # vrrp script looks for this file to update mdns repeater

            if len(mdns['interface']) < 2:
                call('systemctl stop avahi-daemon.service')
                return None

        call('systemctl restart avahi-daemon.service')

    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)