diff options
Diffstat (limited to 'src/op_mode/show_nat_translations.py')
| -rwxr-xr-x | src/op_mode/show_nat_translations.py | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/src/op_mode/show_nat_translations.py b/src/op_mode/show_nat_translations.py new file mode 100755 index 000000000..3af33b78e --- /dev/null +++ b/src/op_mode/show_nat_translations.py @@ -0,0 +1,200 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2020 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'] + sp = l4.get(SPORT, '') + dp = l4.get(DPORT, '') + if sp: + sport[direction] = sp + if dp: + dport[direction] = dp + 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() |