summaryrefslogtreecommitdiff
path: root/python/vyos/nat.py
blob: e1dfff54143d7e381c06c1c3ed564e3b5bc03bd2 (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
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
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
#!/usr/bin/env python3
#
# Copyright (C) 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/>.

from vyos.template import is_ip_network
from vyos.util import dict_search_args
from vyos.template import bracketize_ipv6


def parse_nat_rule(rule_conf, rule_id, nat_type, ipv6=False):
    output = []
    ip_prefix = 'ip6' if ipv6 else 'ip'
    log_prefix = ('DST' if nat_type == 'destination' else 'SRC') + f'-NAT-{rule_id}'
    log_suffix = ''

    if ipv6:
        log_prefix = log_prefix.replace("NAT-", "NAT66-")

    ignore_type_addr = False
    translation_str = ''

    if 'inbound_interface' in rule_conf:
        ifname = rule_conf['inbound_interface']
        if ifname != 'any':
            output.append(f'iifname "{ifname}"')

    if 'outbound_interface' in rule_conf:
        ifname = rule_conf['outbound_interface']
        if ifname != 'any':
            output.append(f'oifname "{ifname}"')

    if 'protocol' in rule_conf and rule_conf['protocol'] != 'all':
        protocol = rule_conf['protocol']
        if protocol == 'tcp_udp':
            protocol = '{ tcp, udp }'
        output.append(f'meta l4proto {protocol}')

    if 'exclude' in rule_conf:
        translation_str = 'return'
        log_suffix = '-EXCL'
    elif 'translation' in rule_conf:
        translation_prefix = nat_type[:1]
        translation_output = [f'{translation_prefix}nat']
        addr = dict_search_args(rule_conf, 'translation', 'address')
        port = dict_search_args(rule_conf, 'translation', 'port')

        if addr and is_ip_network(addr):
            if not ipv6:
                map_addr =  dict_search_args(rule_conf, nat_type, 'address')
                translation_output.append(f'{ip_prefix} prefix to {ip_prefix} {translation_prefix}addr map {{ {map_addr} : {addr} }}')
                ignore_type_addr = True
            else:
                translation_output.append(f'prefix to {addr}')
        elif addr == 'masquerade':
            if port:
                addr = f'{addr} to '
            translation_output = [addr]
            log_suffix = '-MASQ'
        else:
            translation_output.append('to')
            if addr:
                if ipv6:
                    addr = bracketize_ipv6(addr)
                translation_output.append(addr)

        options = []
        addr_mapping = dict_search_args(rule_conf, 'translation', 'options', 'address_mapping')
        port_mapping = dict_search_args(rule_conf, 'translation', 'options', 'port_mapping')
        if addr_mapping == 'persistent':
            options.append('persistent')
        if port_mapping and port_mapping != 'none':
            options.append(port_mapping)

        translation_str = " ".join(translation_output) + (f':{port}' if port else '')

        if options:
            translation_str += f' {",".join(options)}'

    for target in ['source', 'destination']:
        if target not in rule_conf:
            continue

        side_conf = rule_conf[target]
        prefix = target[:1]

        addr = dict_search_args(side_conf, 'address')
        if addr and not (ignore_type_addr and target == nat_type):
            operator = ''
            if addr[:1] == '!':
                operator = '!='
                addr = addr[1:]
            output.append(f'{ip_prefix} {prefix}addr {operator} {addr}')

        addr_prefix = dict_search_args(side_conf, 'prefix')
        if addr_prefix and ipv6:
            operator = ''
            if addr_prefix[:1] == '!':
                operator = '!='
                addr_prefix = addr[1:]
            output.append(f'ip6 {prefix}addr {operator} {addr_prefix}')

        port = dict_search_args(side_conf, 'port')
        if port:
            protocol = rule_conf['protocol']
            if protocol == 'tcp_udp':
                protocol = 'th'
            operator = ''
            if port[:1] == '!':
                operator = '!='
                port = port[1:]
            output.append(f'{protocol} {prefix}port {operator} {{ {port} }}')

        if 'group' in side_conf:
            group = side_conf['group']
            if 'address_group' in group and not (ignore_type_addr and target == nat_type):
                group_name = group['address_group']
                operator = ''
                if group_name[0] == '!':
                    operator = '!='
                    group_name = group_name[1:]
                output.append(f'{ip_prefix} {prefix}addr {operator} @A_{group_name}')
            # Generate firewall group domain-group
            elif 'domain_group' in group and not (ignore_type_addr and target == nat_type):
                group_name = group['domain_group']
                operator = ''
                if group_name[0] == '!':
                    operator = '!='
                    group_name = group_name[1:]
                output.append(f'{ip_prefix} {prefix}addr {operator} @D_{group_name}')
            elif 'network_group' in group and not (ignore_type_addr and target == nat_type):
                group_name = group['network_group']
                operator = ''
                if group_name[0] == '!':
                    operator = '!='
                    group_name = group_name[1:]
                output.append(f'{ip_prefix} {prefix}addr {operator} @N_{group_name}')
            if 'mac_group' in group:
                group_name = group['mac_group']
                operator = ''
                if group_name[0] == '!':
                    operator = '!='
                    group_name = group_name[1:]
                output.append(f'ether {prefix}addr {operator} @M_{group_name}')
            if 'port_group' in group:
                proto = rule_conf['protocol']
                group_name = group['port_group']

                if proto == 'tcp_udp':
                    proto = 'th'

                operator = ''
                if group_name[0] == '!':
                    operator = '!='
                    group_name = group_name[1:]

                output.append(f'{proto} {prefix}port {operator} @P_{group_name}')

    output.append('counter')

    if 'log' in rule_conf:
        output.append(f'log prefix "[{log_prefix}{log_suffix}]"')

    if translation_str:
        output.append(translation_str)

    output.append(f'comment "{log_prefix}"')

    return " ".join(output)

def parse_nat_static_rule(rule_conf, rule_id, nat_type):
    output = []
    log_prefix = ('STATIC-DST' if nat_type == 'destination' else 'STATIC-SRC') + f'-NAT-{rule_id}'
    log_suffix = ''

    ignore_type_addr = False
    translation_str = ''

    if 'inbound_interface' in rule_conf:
        ifname = rule_conf['inbound_interface']
        ifprefix = 'i' if nat_type == 'destination' else 'o'
        if ifname != 'any':
            output.append(f'{ifprefix}ifname "{ifname}"')

    if 'exclude' in rule_conf:
        translation_str = 'return'
        log_suffix = '-EXCL'
    elif 'translation' in rule_conf:
        translation_prefix = nat_type[:1]
        translation_output = [f'{translation_prefix}nat']
        addr = dict_search_args(rule_conf, 'translation', 'address')
        map_addr =  dict_search_args(rule_conf, 'destination', 'address')

        if nat_type == 'source':
            addr, map_addr = map_addr, addr # Swap

        if addr and is_ip_network(addr):
            translation_output.append(f'ip prefix to ip {translation_prefix}addr map {{ {map_addr} : {addr} }}')
            ignore_type_addr = True
        elif addr:
            translation_output.append(f'to {addr}')

        options = []
        addr_mapping = dict_search_args(rule_conf, 'translation', 'options', 'address_mapping')
        port_mapping = dict_search_args(rule_conf, 'translation', 'options', 'port_mapping')
        if addr_mapping == 'persistent':
            options.append('persistent')
        if port_mapping and port_mapping != 'none':
            options.append(port_mapping)

        if options:
            translation_output.append(",".join(options))

        translation_str = " ".join(translation_output)

    prefix = nat_type[:1]
    addr = dict_search_args(rule_conf, 'translation' if nat_type == 'source' else nat_type, 'address')
    if addr and not ignore_type_addr:
        output.append(f'ip {prefix}addr {addr}')

    output.append('counter')

    if translation_str:
        output.append(translation_str)

    if 'log' in rule_conf:
        output.append(f'log prefix "[{log_prefix}{log_suffix}]"')

    output.append(f'comment "{log_prefix}"')

    return " ".join(output)