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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
#!/usr/bin/env python3
#
# Copyright (C) 2018 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 sys
import os
import time
import netifaces
from vyos.config import Config
from vyos.util import ConfigError
config_file = r'/etc/powerdns/recursor.conf'
# borrowed from: https://github.com/donjajo/py-world/blob/master/resolvconfReader.py, THX!
def get_resolvers(file):
resolvers = []
try:
with open(file, 'r') as resolvconf:
for line in resolvconf.readlines():
line = line.split('#',1)[0];
line = line.rstrip();
if 'nameserver' in line:
resolvers.append(line.split()[1])
return resolvers
except IOError:
return []
def get_config():
dns = {}
conf = Config()
conf.set_level('service dns forwarding')
if not conf.exists(''):
return dns
if conf.exists('cache-size'):
cache = conf.return_value('cache-size')
dns.setdefault('cache-size', cache)
if conf.exists('dhcp'):
dns.setdefault('dhcp', [])
interfaces = []
interfaces = conf.return_values('dhcp')
for interface in interfaces:
resolvers = get_resolvers("/etc/resolv.conf.dhclient-new-{0}".format(interface))
if len(resolvers) > 0:
dhcp = {
"interface": interface,
"resolvers": resolvers
}
dns['dhcp'].append(dhcp)
if conf.exists('domain'):
dns.setdefault('domain', [])
for node in conf.list_nodes('domain'):
server = conf.return_values("domain {0} server".format(node))
domain = {
"name": node,
"server": server
}
dns['domain'].append(domain)
if conf.exists('ignore-hosts-file'):
dns.setdefault('ignore-hosts-file', True)
if conf.exists('listen-on'):
interfaces = []
interfaces = conf.return_values('listen-on')
dns.setdefault('listen-on', interfaces)
if conf.exists('name-server'):
nameservers = []
nameservers = conf.return_values('name-server')
dns.setdefault('name-server', nameservers)
if conf.exists('system'):
conf.set_level('system')
nameservers = []
nameservers = conf.return_values('name-server')
if len(nameservers) == 0:
print("DNS forwarding warning: No name-servers set under 'system name-server'\n")
else:
dns.setdefault('system-name-server', nameservers)
return dns
def verify(dns):
if len(dns) > 0:
if 'listen-on' not in dns.keys():
raise ConfigError('Error: DNS forwarding requires a configured listen interface!')
for interface in dns['listen-on']:
try:
netifaces.ifaddresses(interface)[netifaces.AF_INET]
except KeyError as e:
raise ConfigError('Error: Interface {0} has no IP address assigned'.format(interface))
if 'domain' in dns.keys():
for domain in dns['domain']:
if len(domain['server']) == 0:
raise ConfigError('Error: No server configured for domain {0}'.format(domain['name']))
return None
def generate(dns):
config_header = '### Autogenerated by vyos-config-dns-forwarding.py on {tm} ###\n'.format(tm=time.strftime("%a, %d %b %Y %H:%M:%S", time.localtime()))
fwds = []
fwds_src = []
# write new configuration file
f = open(config_file, 'w')
f.write(config_header)
f.write('daemon=yes\n')
f.write('threads=1\n')
f.write('allow-from=0.0.0.0/0\n')
f.write('log-common-errors=yes\n')
if 'listen-on' in dns.keys():
listen4 = []
listen6 = []
for interface in dns['listen-on']:
addrs = netifaces.ifaddresses(interface)
for ip4 in addrs[netifaces.AF_INET]:
listen4.append(ip4['addr'])
for ip6 in addrs[netifaces.AF_INET6]:
listen6.append(ip6['addr'])
# build local-address string, example:
# local-address=172.16.37.240, 127.0.0.1, 172.16.254.35, 172.16.77.1, 2001:DB8::1:25, ::1
f.write('local-address=' + ', '.join(listen4) + ', ' + ', '.join(listen6) + '\n')
if 'cache-size' in dns.keys():
f.write("max-cache-entries={0}\n".format(dns['cache-size']))
if 'dhcp' in dns.keys():
for dhcp in dns['dhcp']:
fwds_src.append('DHCP: {0} ({1})'.format(dhcp['interface'], ', '.join(str(ns) for ns in dhcp['resolvers'])))
fwds.append(', '.join(str(ns) for ns in dhcp['resolvers']))
if 'domain' in dns.keys():
zones = []
for domain in dns['domain']:
zones.append('{0}={1}'.format(domain['name'], ';'.join(str(ns) for ns in domain['server'])))
f.write('forward-zones=' + ', '.join(zones) + '\n')
if 'ignore-hosts-file' in dns.keys():
f.write("export-etc-hosts=no\n")
if 'name-server' in dns.keys():
fwds_src.append('statically configured: {0}'.format(', '.join(str(ns) for ns in dns['name-server'])))
fwds.append(', '.join(str(ns) for ns in dns['name-server']))
if 'system-name-server' in dns.keys():
fwds_src.append('system: {0}'.format(', '.join(str(ns) for ns in dns['system-name-server'])))
fwds.append(', '.join(str(ns) for ns in dns['system-name-server']))
if len(fwds) > 0:
f.write('\n')
f.write('# ' + '\n# '.join(fwds_src) + '\n')
f.write('forward-zones-recurse=.=' + '; '.join(fwds) + '\n')
f.close()
return None
def apply(dns):
if len(dns) == 0:
cmd = "sudo systemctl stop pdns-recursor"
else:
cmd = "sudo systemctl restart pdns-recursor"
os.system(cmd)
return None
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
sys.exit(1)
|
