summaryrefslogtreecommitdiff
path: root/src/op_mode/show_nat_translations.py
blob: db3d2bf0a73056c8a81dd5d0bfec0b4bef363167 (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
#!/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/>.

'''
show nat translations
'''

import os
import sys
import ipaddress
import argparse
import xmltodict

from vyos.util import popen
from vyos.util import DEVNULL

conntrack = '/usr/sbin/conntrack'

verbose_format = "%-20s %-18s %-20s %-18s"
normal_format = "%-20s %-20s %-4s  %-8s %s"


def headers(verbose, pipe):
    if verbose:
        return verbose_format % ('Pre-NAT src', 'Pre-NAT dst', 'Post-NAT src', 'Post-NAT dst')
    return normal_format % ('Pre-NAT', 'Post-NAT', 'Prot', 'Timeout', 'Type' if pipe else '')


def command(srcdest, proto, ipaddr):
    command = f'{conntrack} -o xml -L'

    if proto:
        command += f' -p {proto}'

    if srcdest == 'source':
        command += ' -n'
        if ipaddr:
            command += f' --orig-src {ipaddr}'
    if srcdest == 'destination':
        command += ' -g'

    return command


def run(command):
    xml, code = popen(command,stderr=DEVNULL)
    if code:
        sys.exit('conntrack failed')
    return xml


def content(xmlfile):
    xml = ''
    with open(xmlfile,'r') as r:
        xml += r.read()
    return xml


def pipe():
    xml = ''
    while True:
        line = sys.stdin.readline()
        xml += line
        if '</conntrack>' in line:
            break

    sys.stdin = open('/dev/tty')
    return xml


def process(data, stats, protocol, pipe, verbose, flowtype=''):
    if not data:
        return
 
    parsed = xmltodict.parse(data)

    print(headers(verbose, pipe))

    # to help the linter to detect typos
    ORIGINAL = 'original'
    REPLY = 'reply'
    INDEPENDANT = 'independent'
    SPORT = 'sport'
    DPORT = 'dport'
    SRC = 'src'
    DST = 'dst'

    for rule in parsed['conntrack']['flow']:
        src, dst, sport, dport, proto = {}, {}, {}, {}, {}
        packet_count, byte_count = {}, {}
        timeout, use = 0, 0

        rule_type = rule.get('type', '')
 
        for meta in rule['meta']:
            # print(meta)
            direction = meta['@direction']

            if direction in (ORIGINAL, REPLY):
                if 'layer3' in meta:
                    l3 = meta['layer3']
                    src[direction] = l3[SRC]
                    dst[direction] = l3[DST]

                if 'layer4' in meta:
                    l4 = meta['layer4']
                    sport[direction] = l4[SPORT]
                    dport[direction] = l4[DPORT]
                    proto[direction] = l4.get('@protoname','')

                if stats and 'counters' in meta:
                    packet_count[direction] = meta['packets']
                    byte_count[direction] = meta['bytes']
                continue

            if direction == INDEPENDANT:
                timeout = meta['timeout']
                use = meta['use']
                continue

        in_src = '%s:%s' % (src[ORIGINAL], sport[ORIGINAL]) if ORIGINAL in sport else src[ORIGINAL]
        in_dst = '%s:%s' % (dst[ORIGINAL], dport[ORIGINAL]) if ORIGINAL in dport else dst[ORIGINAL]

        # inverted the the perl code !!?
        out_dst = '%s:%s' % (dst[REPLY], dport[REPLY]) if REPLY in dport else dst[REPLY]
        out_src = '%s:%s' % (src[REPLY], sport[REPLY]) if REPLY in sport else src[REPLY]

        if flowtype == 'source':
            v = ORIGINAL in sport and REPLY in dport
            f = '%s:%s' % (src[ORIGINAL], sport[ORIGINAL]) if v else src[ORIGINAL]
            t = '%s:%s' % (dst[REPLY], dport[REPLY]) if v else dst[REPLY]
        else:
            v = ORIGINAL in dport and REPLY in sport
            f = '%s:%s' % (dst[ORIGINAL], dport[ORIGINAL]) if v else dst[ORIGINAL]
            t = '%s:%s' % (src[REPLY], sport[REPLY]) if v else src[REPLY]

        # Thomas: I do not believe proto should be an option
        p = proto.get('original', '')
        if protocol and p != protocol:
            continue

        if verbose:
            msg = verbose_format % (in_src, in_dst, out_dst, out_src)
            p = f'{p}: ' if p else ''
            msg += f'\n  {p}{f} ==> {t}'
            msg += f' timeout: {timeout}' if timeout else ''
            msg += f' use: {use} ' if use else ''
            msg += f' type: {rule_type}' if rule_type else ''
            print(msg)
        else:
            print(normal_format % (f, t, p, timeout, rule_type if rule_type else ''))

        if stats:
            for direction in ('original', 'reply'):
                if direction in packet_count:
                    print('  %-8s: packets %s, bytes %s' % direction, packet_count[direction], byte_count[direction])


def main():
    parser = argparse.ArgumentParser(description=sys.modules[__name__].__doc__)
    parser.add_argument('--verbose', help='provide more details about the flows', action='store_true')
    parser.add_argument('--proto', help='filter by protocol', default='', type=str)
    parser.add_argument('--file', help='read the conntrack xml from a file', type=str)
    parser.add_argument('--stats', help='add usage statistics', action='store_true')
    parser.add_argument('--type', help='NAT type (source, destination)', required=True, type=str)
    parser.add_argument('--ipaddr', help='source ip address to filter on', type=ipaddress.ip_address)
    parser.add_argument('--pipe', help='read conntrack xml data from stdin', action='store_true')

    arg = parser.parse_args()

    if arg.type not in ('source', 'destination'):
        sys.exit('Unknown NAT type!')

    if arg.pipe:
        process(pipe(), arg.stats, arg.proto, arg.pipe, arg.verbose, arg.type)
    elif arg.file:
        process(content(arg.file), arg.stats, arg.proto, arg.pipe, arg.verbose, arg.type)
    else:
        process(run(command(arg.type, arg.proto, arg.ipaddr)), arg.stats, arg.proto, arg.pipe, arg.verbose, arg.type)


if __name__ == '__main__':
    main()