mirror of
https://github.com/sshuttle/sshuttle.git
synced 2024-11-22 16:03:57 +01:00
Re-introduce ipfw support for sshuttle on FreeBSD with support for --DNS option as well
Sponsored-by: rsync.net
This commit is contained in:
Ermal Luci
Brian May
parent
e8ceccc3d5
commit
5e90491344
@ -98,6 +98,8 @@ def get_auto_method():
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method_name = "nat"
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elif _program_exists('pfctl'):
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method_name = "pf"
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elif _program_exists('ipfw'):
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method_name = "ipfw"
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else:
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raise Fatal(
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"can't find either iptables or pfctl; check your PATH")
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268
sshuttle/methods/ipfw.py
Normal file
268
sshuttle/methods/ipfw.py
Normal file
@ -0,0 +1,268 @@
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import os
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import sys
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import struct
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import subprocess as ssubprocess
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from sshuttle.methods import BaseMethod
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from sshuttle.helpers import log, debug1, debug3, \
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Fatal, family_to_string
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recvmsg = None
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try:
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# try getting recvmsg from python
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import socket as pythonsocket
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getattr(pythonsocket.socket, "recvmsg")
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socket = pythonsocket
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recvmsg = "python"
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except AttributeError:
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# try getting recvmsg from socket_ext library
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try:
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import socket_ext
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getattr(socket_ext.socket, "recvmsg")
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socket = socket_ext
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recvmsg = "socket_ext"
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except ImportError:
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import socket
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IP_BINDANY = 24
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IP_RECVDSTADDR = 7
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SOL_IPV6 = 41
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IPV6_RECVDSTADDR = 74
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if recvmsg == "python":
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def recv_udp(listener, bufsize):
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debug3('Accept UDP python using recvmsg.\n')
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data, ancdata, msg_flags, srcip = listener.recvmsg(4096, socket.CMSG_SPACE(4))
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dstip = None
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family = None
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for cmsg_level, cmsg_type, cmsg_data in ancdata:
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if cmsg_level == socket.SOL_IP and cmsg_type == IP_RECVDSTADDR:
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port = 53
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ip = socket.inet_ntop(socket.AF_INET, cmsg_data[0:4])
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dstip = (ip, port)
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break
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return (srcip, dstip, data)
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elif recvmsg == "socket_ext":
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def recv_udp(listener, bufsize):
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debug3('Accept UDP using socket_ext recvmsg.\n')
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srcip, data, adata, flags = listener.recvmsg((bufsize,), socket.CMSG_SPACE(4))
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dstip = None
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family = None
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for a in adata:
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if a.cmsg_level == socket.SOL_IP and a.cmsg_type == IP_RECVDSTADDR:
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port = 53
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ip = socket.inet_ntop(socket.AF_INET, cmsg_data[0:4])
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dstip = (ip, port)
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break
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return (srcip, dstip, data[0])
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else:
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def recv_udp(listener, bufsize):
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debug3('Accept UDP using recvfrom.\n')
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data, srcip = listener.recvfrom(bufsize)
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return (srcip, None, data)
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def ipfw_rule_exists(n):
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argv = ['ipfw', 'list']
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env = {
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'PATH': os.environ['PATH'],
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'LC_ALL': "C",
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}
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p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, env=env)
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found = False
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for line in p.stdout:
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if line.startswith(b'%05d ' % n):
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if not ('ipttl 42' in line or 'check-state' in line):
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log('non-sshuttle ipfw rule: %r\n' % line.strip())
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raise Fatal('non-sshuttle ipfw rule #%d already exists!' % n)
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found = True
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rv = p.wait()
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if rv:
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raise Fatal('%r returned %d' % (argv, rv))
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return found
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_oldctls = {}
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def _fill_oldctls(prefix):
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argv = ['sysctl', prefix]
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env = {
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'PATH': os.environ['PATH'],
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'LC_ALL': "C",
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}
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p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, env=env)
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for line in p.stdout:
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line = line.decode()
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assert(line[-1] == '\n')
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(k, v) = line[:-1].split(': ', 1)
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_oldctls[k] = v.strip()
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rv = p.wait()
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if rv:
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raise Fatal('%r returned %d' % (argv, rv))
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if not line:
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raise Fatal('%r returned no data' % (argv,))
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def _sysctl_set(name, val):
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argv = ['sysctl', '-w', '%s=%s' % (name, val)]
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debug1('>> %s\n' % ' '.join(argv))
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return ssubprocess.call(argv, stdout=open('/dev/null', 'w'))
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_changedctls = []
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def sysctl_set(name, val, permanent=False):
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PREFIX = 'net.inet.ip'
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assert(name.startswith(PREFIX + '.'))
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val = str(val)
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if not _oldctls:
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_fill_oldctls(PREFIX)
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if not (name in _oldctls):
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debug1('>> No such sysctl: %r\n' % name)
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return False
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oldval = _oldctls[name]
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if val != oldval:
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rv = _sysctl_set(name, val)
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if rv == 0 and permanent:
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debug1('>> ...saving permanently in /etc/sysctl.conf\n')
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f = open('/etc/sysctl.conf', 'a')
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f.write('\n'
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'# Added by sshuttle\n'
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'%s=%s\n' % (name, val))
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f.close()
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else:
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_changedctls.append(name)
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return True
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def ipfw(*args):
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argv = ['ipfw', '-q'] + list(args)
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debug1('>> %s\n' % ' '.join(argv))
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rv = ssubprocess.call(argv)
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if rv:
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raise Fatal('%r returned %d' % (argv, rv))
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def ipfw_noexit(*args):
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argv = ['ipfw', '-q'] + list(args)
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debug1('>> %s\n' % ' '.join(argv))
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ssubprocess.call(argv)
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class Method(BaseMethod):
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def get_supported_features(self):
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result = super(Method, self).get_supported_features()
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result.ipv6 = False
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result.udp = False #NOTE: Almost there, kernel patch needed
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result.dns = True
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return result
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def get_tcp_dstip(self, sock):
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return sock.getsockname()
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def recv_udp(self, udp_listener, bufsize):
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srcip, dstip, data = recv_udp(udp_listener, bufsize)
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if not dstip:
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debug1(
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"-- ignored UDP from %r: "
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"couldn't determine destination IP address\n" % (srcip,))
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return None
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return srcip, dstip, data
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def send_udp(self, sock, srcip, dstip, data):
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if not srcip:
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debug1(
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"-- ignored UDP to %r: "
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"couldn't determine source IP address\n" % (dstip,))
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return
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#debug3('Sending SRC: %r DST: %r\n' % (srcip, dstip))
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sender = socket.socket(sock.family, socket.SOCK_DGRAM)
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sender.setsockopt(socket.SOL_IP, IP_BINDANY, 1)
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sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
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sender.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
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sender.bind(srcip)
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sender.sendto(data,dstip)
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sender.close()
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def setup_udp_listener(self, udp_listener):
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if udp_listener.v4 is not None:
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udp_listener.v4.setsockopt(socket.SOL_IP, IP_RECVDSTADDR, 1)
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#if udp_listener.v6 is not None:
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# udp_listener.v6.setsockopt(SOL_IPV6, IPV6_RECVDSTADDR, 1)
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def setup_firewall(self, port, dnsport, nslist, family, subnets, udp):
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# IPv6 not supported
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if family not in [socket.AF_INET ]:
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raise Exception(
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'Address family "%s" unsupported by ipfw method_name'
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% family_to_string(family))
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#XXX: Any risk from this?
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ipfw_noexit('delete', '1')
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while _changedctls:
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name = _changedctls.pop()
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oldval = _oldctls[name]
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_sysctl_set(name, oldval)
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if subnets or dnsport:
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sysctl_set('net.inet.ip.fw.enable', 1)
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ipfw('add', '1', 'check-state', 'ip',
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'from', 'any', 'to', 'any')
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ipfw('add', '1', 'skipto', '2',
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'tcp',
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'from', 'any', 'to', 'table(125)')
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ipfw('add', '1', 'fwd', '127.0.0.1,%d' % port,
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'tcp',
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'from', 'any', 'to', 'table(126)',
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'not', 'ipttl', '42', 'keep-state', 'setup')
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ipfw_noexit('table', '124', 'flush')
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dnscount = 0
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for f, ip in [i for i in nslist if i[0] == family]:
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ipfw('table', '124', 'add', '%s' % (ip))
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dnscount += 1
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if dnscount > 0:
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ipfw('add', '1', 'fwd', '127.0.0.1,%d' % dnsport,
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'udp',
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'from', 'any', 'to', 'table(124)',
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'not', 'ipttl', '42')
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"""if udp:
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ipfw('add', '1', 'skipto', '2',
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'udp',
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'from', 'any', 'to', 'table(125)')
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ipfw('add', '1', 'fwd', '127.0.0.1,%d' % port,
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'udp',
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'from', 'any', 'to', 'table(126)',
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'not', 'ipttl', '42')
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"""
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ipfw('add', '1', 'allow',
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'udp',
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'from', 'any', 'to', 'any',
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'ipttl', '42')
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if subnets:
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# create new subnet entries
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for f, swidth, sexclude, snet \
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in sorted(subnets, key=lambda s: s[1], reverse=True):
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if sexclude:
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ipfw('table', '125', 'add', '%s/%s' % (snet, swidth))
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else:
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ipfw('table', '126', 'add', '%s/%s' % (snet, swidth))
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def restore_firewall(self, port, family, udp):
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if family not in [socket.AF_INET]:
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raise Exception(
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'Address family "%s" unsupported by tproxy method'
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% family_to_string(family))
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ipfw_noexit('delete', '1')
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ipfw_noexit('table', '124', 'flush')
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ipfw_noexit('table', '125', 'flush')
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ipfw_noexit('table', '126', 'flush')
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@ -162,7 +162,7 @@ parser.add_argument(
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)
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parser.add_argument(
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"--method",
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choices=["auto", "nat", "tproxy", "pf"],
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choices=["auto", "nat", "tproxy", "pf", "ipfw"],
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metavar="TYPE",
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default="auto",
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help="""
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