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
|
#!/usr/bin/env python3
#
# Copyright (C) 2021 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
import re
from sys import argv
from sys import exit
from vyos.config import Config
from vyos.configdict import leaf_node_changed
from vyos.ifconfig import Section
from vyos.template import render
from vyos.util import cmd
from vyos.util import dict_search_args
from vyos.util import run
from vyos import ConfigError
from vyos import airbag
airbag.enable()
NAME_PREFIX = 'NAME_'
NAME6_PREFIX = 'NAME6_'
NFT_CHAINS = {
'in': 'VYOS_FW_FORWARD',
'out': 'VYOS_FW_FORWARD',
'local': 'VYOS_FW_LOCAL'
}
NFT6_CHAINS = {
'in': 'VYOS_FW6_FORWARD',
'out': 'VYOS_FW6_FORWARD',
'local': 'VYOS_FW6_LOCAL'
}
def get_config(config=None):
if config:
conf = config
else:
conf = Config()
ifname = argv[1]
ifpath = Section.get_config_path(ifname)
if_firewall_path = f'interfaces {ifpath} firewall'
if_firewall = conf.get_config_dict(if_firewall_path, key_mangling=('-', '_'), get_first_key=True,
no_tag_node_value_mangle=True)
if_firewall['ifname'] = ifname
if_firewall['firewall'] = conf.get_config_dict(['firewall'], key_mangling=('-', '_'), get_first_key=True,
no_tag_node_value_mangle=True)
return if_firewall
def verify(if_firewall):
# bail out early - looks like removal from running config
if not if_firewall:
return None
for direction in ['in', 'out', 'local']:
if direction in if_firewall:
if 'name' in if_firewall[direction]:
name = if_firewall[direction]['name']
if 'name' not in if_firewall['firewall']:
raise ConfigError('Firewall name not configured')
if name not in if_firewall['firewall']['name']:
raise ConfigError(f'Invalid firewall name "{name}"')
if 'ipv6_name' in if_firewall[direction]:
name = if_firewall[direction]['ipv6_name']
if 'ipv6_name' not in if_firewall['firewall']:
raise ConfigError('Firewall ipv6-name not configured')
if name not in if_firewall['firewall']['ipv6_name']:
raise ConfigError(f'Invalid firewall ipv6-name "{name}"')
return None
def generate(if_firewall):
return None
def cleanup_rule(table, chain, prefix, ifname, new_name=None):
results = cmd(f'nft -a list chain {table} {chain}').split("\n")
retval = None
for line in results:
if f'{prefix}ifname "{ifname}"' in line:
if new_name and f'jump {new_name}' in line:
# new_name is used to clear rules for any previously referenced chains
# returns true when rule exists and doesn't need to be created
retval = True
continue
handle_search = re.search('handle (\d+)', line)
if handle_search:
run(f'nft delete rule {table} {chain} handle {handle_search[1]}')
return retval
def state_policy_handle(table, chain):
# Find any state-policy rule to ensure interface rules are only inserted afterwards
results = cmd(f'nft -a list chain {table} {chain}').split("\n")
for line in results:
if 'jump VYOS_STATE_POLICY' in line:
handle_search = re.search('handle (\d+)', line)
if handle_search:
return handle_search[1]
return None
def apply(if_firewall):
ifname = if_firewall['ifname']
for direction in ['in', 'out', 'local']:
chain = NFT_CHAINS[direction]
ipv6_chain = NFT6_CHAINS[direction]
if_prefix = 'i' if direction in ['in', 'local'] else 'o'
name = dict_search_args(if_firewall, direction, 'name')
if name:
rule_exists = cleanup_rule('ip filter', chain, if_prefix, ifname, f'{NAME_PREFIX}{name}')
if not rule_exists:
rule_action = 'insert'
rule_prefix = ''
handle = state_policy_handle('ip filter', chain)
if handle:
rule_action = 'add'
rule_prefix = f'position {handle}'
run(f'nft {rule_action} rule ip filter {chain} {rule_prefix} {if_prefix}ifname {ifname} counter jump {NAME_PREFIX}{name}')
else:
cleanup_rule('ip filter', chain, if_prefix, ifname)
ipv6_name = dict_search_args(if_firewall, direction, 'ipv6_name')
if ipv6_name:
rule_exists = cleanup_rule('ip6 filter', ipv6_chain, if_prefix, ifname, f'{NAME6_PREFIX}{ipv6_name}')
if not rule_exists:
rule_action = 'insert'
rule_prefix = ''
handle = state_policy_handle('ip6 filter', ipv6_chain)
if handle:
rule_action = 'add'
rule_prefix = f'position {handle}'
run(f'nft {rule_action} rule ip6 filter {ipv6_chain} {rule_prefix} {if_prefix}ifname {ifname} counter jump {NAME6_PREFIX}{ipv6_name}')
else:
cleanup_rule('ip6 filter', ipv6_chain, if_prefix, ifname)
return None
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
exit(1)
|
