diff --git a/docs/manpage.rst b/docs/manpage.rst index 34516ed..02a669e 100644 --- a/docs/manpage.rst +++ b/docs/manpage.rst @@ -44,7 +44,7 @@ Options to during startup will be routed over the VPN. Valid examples are example.com, example.com:8000 and example.com:8000-9000. -.. option:: --method [auto|nat|tproxy|pf] +.. option:: --method [auto|nat|nft|tproxy|pf] Which firewall method should sshuttle use? For auto, sshuttle attempts to guess the appropriate method depending on what it can find in PATH. The diff --git a/sshuttle/linux.py b/sshuttle/linux.py index 76ae7e0..0388a3c 100644 --- a/sshuttle/linux.py +++ b/sshuttle/linux.py @@ -1,8 +1,6 @@ -import re import os import socket import subprocess as ssubprocess - from sshuttle.helpers import log, debug1, Fatal, family_to_string @@ -52,10 +50,8 @@ def ipt(family, table, *args): def nft(family, table, action, *args): - if family == socket.AF_INET: - argv = ['nft', action, 'ip', table] + list(args) - elif family == socket.AF_INET6: - argv = ['nft', action, 'ip6', table] + list(args) + if family in (socket.AF_INET, socket.AF_INET6): + argv = ['nft', action, 'inet', table] + list(args) else: raise Exception('Unsupported family "%s"' % family_to_string(family)) debug1('>> %s\n' % ' '.join(argv)) @@ -68,48 +64,6 @@ def nft(family, table, action, *args): raise Fatal('%r returned %d' % (argv, rv)) -def nft_chain_exists(family, table, name): - if family == socket.AF_INET: - fam = 'ip' - elif family == socket.AF_INET6: - fam = 'ip6' - else: - raise Exception('Unsupported family "%s"' % family_to_string(family)) - argv = ['nft', 'list', 'chain', fam, table, name] - debug1('>> %s\n' % ' '.join(argv)) - env = { - 'PATH': os.environ['PATH'], - 'LC_ALL': "C", - } - try: - table_exists = False - output = ssubprocess.check_output(argv, env=env, - stderr=ssubprocess.STDOUT) - for line in output.decode('ASCII').split('\n'): - if line.startswith('table %s %s ' % (fam, table)): - table_exists = True - if table_exists and ('chain %s {' % name) in line: - return True - except ssubprocess.CalledProcessError: - return False - - -def nft_get_handle(expression, chain): - cmd = 'nft' - argv = [cmd, 'list', expression, '-a'] - env = { - 'PATH': os.environ['PATH'], - 'LC_ALL': "C", - } - try: - output = ssubprocess.check_output(argv, env=env) - for line in output.decode('utf-8').split('\n'): - if ('jump %s' % chain) in line: - return re.sub('.*# ', '', line) - except ssubprocess.CalledProcessError as e: - raise Fatal('%r returned %d' % (argv, e.returncode)) - - _no_ttl_module = False diff --git a/sshuttle/methods/nft.py b/sshuttle/methods/nft.py index dbc0501..0d58abb 100644 --- a/sshuttle/methods/nft.py +++ b/sshuttle/methods/nft.py @@ -1,6 +1,6 @@ import socket from sshuttle.firewall import subnet_weight -from sshuttle.linux import nft, nft_get_handle, nft_chain_exists, nonfatal +from sshuttle.linux import nft, nonfatal from sshuttle.methods import BaseMethod @@ -16,22 +16,19 @@ class Method(BaseMethod): if udp: raise Exception("UDP not supported by nft") - table = "nat" + table = 'sshuttle-%s' % port def _nft(action, *args): return nft(family, table, action, *args) + chain = table + # basic cleanup/setup of chains _nft('add table', '') - # prerouting, postrouting, and output chains may already exist - for chain in ['prerouting', 'postrouting', 'output']: - rules = '{{ type nat hook {} priority -100; policy accept; }}' \ - .format(chain) - if not nft_chain_exists(family, table, chain): - _nft('add chain', chain, rules) - - chain = 'sshuttle-%s' % port - + _nft('add chain', 'prerouting', + '{ type nat hook prerouting priority -100; policy accept; }') + _nft('add chain', 'output', + '{ type nat hook output priority -100; policy accept; }') _nft('add chain', chain) _nft('flush chain', chain) _nft('add rule', 'output jump %s' % chain) @@ -70,16 +67,10 @@ class Method(BaseMethod): if udp: raise Exception("UDP not supported by nft method_name") - table = "nat" + table = 'sshuttle-%s' % port def _nft(action, *args): return nft(family, table, action, *args) - chain = 'sshuttle-%s' % port - # basic cleanup/setup of chains - handle = nft_get_handle('chain ip nat output', chain) - nonfatal(_nft, 'delete rule', 'output', handle) - handle = nft_get_handle('chain ip nat prerouting', chain) - nonfatal(_nft, 'delete rule', 'prerouting', handle) - nonfatal(_nft, 'delete chain', chain) + nonfatal(_nft, 'delete table', '')