From e74859243042f87c4e3e6fa8e90902641d67b081 Mon Sep 17 00:00:00 2001 From: Andrew Topp Date: Sun, 9 Jun 2024 11:48:21 +1000 Subject: [PATCH] T6456: Convert "monitor traffic" to modern op-mode wrapper The old "monitor traffic" definition had misaligned arguments under the verbose node and manually offered the same parameter keyword in multiple positions to emulate flexible parameters. I've wrapped tcpdump for op-mode and replicated the "varargs" style from mtr.py/mtr.xml.in to present a few more parameters in a more flexible manner. Changes to the Makefile were required for recursive varargs lookup. --- Makefile | 3 +- op-mode-definitions/traffic-dump.xml.in | 55 ++------ src/op_mode/tcpdump.py | 165 ++++++++++++++++++++++++ 3 files changed, 175 insertions(+), 48 deletions(-) create mode 100644 src/op_mode/tcpdump.py diff --git a/Makefile b/Makefile index 3b26273d63..cc382e2061 100644 --- a/Makefile +++ b/Makefile @@ -61,12 +61,13 @@ op_mode_definitions: $(op_xml_obj) rm -f $(OP_TMPL_DIR)/clear/node.def rm -f $(OP_TMPL_DIR)/delete/node.def - # XXX: ping, traceroute and mtr must be able to recursivly call themselves as the + # XXX: tcpdump, ping, traceroute and mtr must be able to recursivly call themselves as the # options are provided from the scripts themselves ln -s ../node.tag $(OP_TMPL_DIR)/ping/node.tag/node.tag/ ln -s ../node.tag $(OP_TMPL_DIR)/traceroute/node.tag/node.tag/ ln -s ../node.tag $(OP_TMPL_DIR)/mtr/node.tag/node.tag/ ln -s ../node.tag $(OP_TMPL_DIR)/monitor/traceroute/node.tag/node.tag/ + ln -s ../node.tag $(OP_TMPL_DIR)/monitor/traffic/interface/node.tag/node.tag/ # XXX: test if there are empty node.def files - this is not allowed as these # could mask help strings or mandatory priority statements diff --git a/op-mode-definitions/traffic-dump.xml.in b/op-mode-definitions/traffic-dump.xml.in index 76e3ddce5b..e86e697363 100644 --- a/op-mode-definitions/traffic-dump.xml.in +++ b/op-mode-definitions/traffic-dump.xml.in @@ -8,7 +8,7 @@ - sudo tcpdump -i $4 + ${vyos_op_scripts_dir}/tcpdump.py $4 Monitor traffic dump from an interface @@ -16,54 +16,15 @@ - - sudo tcpdump -vvv -ne -i $4 + - Provide more detailed packets for each monitored traffic + Traffic capture options + + + - - - sudo tcpdump -vvv -ne -i $4 "${@:6}" - - Monitor traffic matching filter conditions - - - - sudo tcpdump -vvv -ne -i $4 -w $6 - - Save traffic dump from an interface to a file - - - - sudo tcpdump -vvv -ne -i $4 -w $6 "${@:8}" - - Save a dump of traffic matching filter conditions to a file - - - - - - - - sudo tcpdump -n -i $4 "${@:6}" - - Monitor traffic matching filter conditions - - - - sudo tcpdump -n -i $4 -w $6 - - Save traffic dump from an interface to a file - - - - sudo tcpdump -n -i $4 -w $6 "${@:8}" - - Save a dump of traffic matching filter conditions to a file - - - - + ${vyos_op_scripts_dir}/tcpdump.py "${@:4}" + diff --git a/src/op_mode/tcpdump.py b/src/op_mode/tcpdump.py new file mode 100644 index 0000000000..607b59603e --- /dev/null +++ b/src/op_mode/tcpdump.py @@ -0,0 +1,165 @@ +#! /usr/bin/env python3 + +# Copyright (C) 2024 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 . + +import sys + +from vyos.utils.process import call + +options = { + 'dump': { + 'cmd': '{command} -A', + 'type': 'noarg', + 'help': 'Print each packet (minus its link level header) in ASCII.' + }, + 'hexdump': { + 'cmd': '{command} -X', + 'type': 'noarg', + 'help': 'Print each packet (minus its link level header) in both hex and ASCII.' + }, + 'filter': { + 'cmd': '{command} \'{value}\'', + 'type': '', + 'help': 'Match traffic for capture and display with a pcap-filter expression.' + }, + 'numeric': { + 'cmd': '{command} -nn', + 'type': 'noarg', + 'help': 'Do not attempt to resolve addresses, protocols or services to names.' + }, + 'save': { + 'cmd': '{command} -w {value}', + 'type': '', + 'help': 'Write captured raw packets to rather than parsing or printing them out.' + }, + 'verbose': { + 'cmd': '{command} -vvv -ne', + 'type': 'noarg', + 'help': 'Parse packets with increased detail output, including link-level headers and extended decoding protocol sanity checks.' + }, +} + +tcpdump = 'sudo /usr/bin/tcpdump' + +class List(list): + def first(self): + return self.pop(0) if self else '' + + def last(self): + return self.pop() if self else '' + + def prepend(self, value): + self.insert(0, value) + + +def completion_failure(option: str) -> None: + """ + Shows failure message after TAB when option is wrong + :param option: failure option + :type str: + """ + sys.stderr.write('\n\n Invalid option: {}\n\n'.format(option)) + sys.stdout.write('') + sys.exit(1) + + +def expansion_failure(option, completions): + reason = 'Ambiguous' if completions else 'Invalid' + sys.stderr.write( + '\n\n {} command: {} [{}]\n\n'.format(reason, ' '.join(sys.argv), + option)) + if completions: + sys.stderr.write(' Possible completions:\n ') + sys.stderr.write('\n '.join(completions)) + sys.stderr.write('\n') + sys.stdout.write('') + sys.exit(1) + + +def complete(prefix): + return [o for o in options if o.startswith(prefix)] + + +def convert(command, args): + while args: + shortname = args.first() + longnames = complete(shortname) + if len(longnames) != 1: + expansion_failure(shortname, longnames) + longname = longnames[0] + if options[longname]['type'] == 'noarg': + command = options[longname]['cmd'].format( + command=command, value='') + elif not args: + sys.exit(f'monitor traffic: missing argument for {longname} option') + else: + command = options[longname]['cmd'].format( + command=command, value=args.first()) + return command + + +if __name__ == '__main__': + args = List(sys.argv[1:]) + ifname = args.first() + + # Slightly simplified & tweaked version of the code from mtr.py - it may be + # worthwhile to combine and centralise this in a common module. + if ifname == '--get-options-nested': + args.first() # pop monitor + args.first() # pop traffic + args.first() # pop interface + args.first() # pop + usedoptionslist = [] + while args: + option = args.first() # pop option + matched = complete(option) # get option parameters + usedoptionslist.append(option) # list of used options + # Select options + if not args: + # remove from Possible completions used options + for o in usedoptionslist: + if o in matched: + matched.remove(o) + if not matched: + sys.stdout.write('') + else: + sys.stdout.write(' '.join(matched)) + sys.exit(0) + + if len(matched) > 1: + sys.stdout.write(' '.join(matched)) + sys.exit(0) + # If option doesn't have value + if matched: + if options[matched[0]]['type'] == 'noarg': + continue + else: + # Unexpected option + completion_failure(option) + + value = args.first() # pop option's value + if not args: + matched = complete(option) + helplines = options[matched[0]]['type'] + # Run helpfunction to get list of possible values + if 'helpfunction' in options[matched[0]]: + result = options[matched[0]]['helpfunction']() + if result: + helplines = '\n' + ' '.join(result) + sys.stdout.write(helplines) + sys.exit(0) + + command = convert(tcpdump, args) + call(f'{command} -i {ifname}')