Version 0.77

In some cases (see #43) it seems that some network configurations may
end up setting a skip on lo. As sshuttle adds rules that rely on
filtering/translating packets on lo, this causes problem. This fix
overrides the skip and makes the rules be applied again.
Should fix at least some of the problems reported on #43.

CHANGES.rst

@@ -1,3 +1,12 @@
+Release 0.77 (Mar 3, 2016)
+==========================
+
+* Various bug fixes.
+* Fix Documentation.
+* Add fix for MacOS X issue.
+* Add support for OpenBSD.
+
+
 Release 0.76 (Jan 17, 2016)
 ===========================
 

MANIFEST.in

@@ -5,6 +5,7 @@ include MANIFEST.in
 include LICENSE
 include run
 include tox.ini
+exclude sshuttle/version.py
 recursive-include docs *.bat
 recursive-include docs *.py
 recursive-include docs *.rst

VERSION.txt

@@ -1 +0,0 @@
-0.75

docs/index.rst

@@ -1,6 +1,9 @@
 sshuttle: where transparent proxy meets VPN meets ssh
 =====================================================
 
+:Date: |today|
+:Version: |version|
+
 Contents:
 
 .. toctree::
@@ -10,6 +13,7 @@ Contents:
    requirements
    installation
    usage
+   platform
    Man Page <manpage>
    how-it-works
    support

docs/manpage.rst

@@ -37,6 +37,12 @@ Options
     netmask), and 0/0 ('just route everything through the
     VPN').
 
+.. option:: --method [auto|nat|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
+   default value is auto.
+
 .. option:: -l, --listen=[ip:]port
 
     Use this ip address and port number as the transparent
@@ -278,7 +284,6 @@ there is no need for congestion control to be shared
 between the two separate streams, so a tcp-based tunnel is
 fine.
 
+.. seealso::
 
-See Also
---------
-:manpage:`ssh(1)`, :manpage:`python(1)`
+   :manpage:`ssh(1)`, :manpage:`python(1)`

docs/platform.rst

@@ -0,0 +1,10 @@
+Platform Specific Notes
+=======================
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   tproxy
+   windows

docs/requirements.rst

@@ -37,11 +37,13 @@ Supports:
 Full UDP or DNS support with the TPROXY method requires the ``recvmsg()``
 syscall. This is not available in Python 2, however is in Python 3.5 and
 later. Under Python 2 you might find it sufficient installing PyXAPI_ to get
-the ``recvmsg()`` function.
+the ``recvmsg()`` function. See :doc:`tproxy` for more information.
 
 
-MacOS with PF method
-~~~~~~~~~~~~~~~~~~~~
+MacOS / FreeBSD / OpenBSD
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Method: pf
+
 Supports:
 
 * IPv4 TCP
@@ -51,6 +53,12 @@ Requires:
 
 * You need to have the pfctl command.
 
+Windows
+~~~~~~~
+
+Not officially supported, however can be made to work with Vagrant. Requires
+cmd.exe with Administrator access. See :doc:`windows` for more information.
+
 
 Server side Requirements
 ------------------------

docs/tproxy.rst

@@ -0,0 +1,42 @@
+TPROXY
+======
+TPROXY is the only method that has full support of IPv6 and UDP.
+
+There are some things you need to consider for TPROXY to work:
+
+- The following commands need to be run first as root. This only needs to be
+  done once after booting up::
+
+      ip route add local default dev lo table 100
+      ip rule add fwmark 1 lookup 100
+      ip -6 route add local default dev lo table 100
+      ip -6 rule add fwmark 1 lookup 100
+
+- The ``--auto-nets`` feature does not detect IPv6 routes automatically. Add IPv6
+  routes manually. e.g. by adding ``'::/0'`` to the end of the command line.
+
+- The client needs to be run as root. e.g.::
+
+      sudo SSH_AUTH_SOCK="$SSH_AUTH_SOCK" $HOME/tree/sshuttle.tproxy/sshuttle  --method=tproxy ...
+
+- You may need to exclude the IP address of the server you are connecting to.
+  Otherwise sshuttle may attempt to intercept the ssh packets, which will not
+  work. Use the ``--exclude`` parameter for this.
+
+- Similarly, UDP return packets (including DNS) could get intercepted and
+  bounced back. This is the case if you have a broad subnet such as
+  ``0.0.0.0/0`` or ``::/0`` that includes the IP address of the client. Use the
+  ``--exclude`` parameter for this.
+
+- You need the ``--method=tproxy`` parameter, as above.
+
+- The routes for the outgoing packets must already exist. For example, if your
+  connection does not have IPv6 support, no IPv6 routes will exist, IPv6
+  packets will not be generated and sshuttle cannot intercept them::
+
+      telnet -6 www.google.com 80
+      Trying 2404:6800:4001:805::1010...
+      telnet: Unable to connect to remote host: Network is unreachable
+
+  Add some dummy routes to external interfaces. Make sure they get removed
+  however after sshuttle exits.

docs/trivia.rst

@@ -3,7 +3,7 @@ Useless Trivia
 This section written by the original author, Avery Pennarun
 <apenwarr@gmail.com>.
 
-Back in 1998 (12 years ago!  Yikes!), I released the first version of `Tunnel
+Back in 1998, I released the first version of `Tunnel
 Vision <http://alumnit.ca/wiki/?TunnelVisionReadMe>`_, a semi-intelligent VPN
 client for Linux.  Unfortunately, I made two big mistakes: I implemented the
 key exchange myself (oops), and I ended up doing TCP-over-TCP (double oops).
@@ -31,6 +31,6 @@ intended.)
 
 That project I did for Slipstream was what first gave me the idea to merge
 the concepts of Fast Forward, Double Vision, and Tunnel Vision into a single
-program that was the best of all worlds.  And here we are, at last, 10 years
-later.  You're welcome.
+program that was the best of all worlds.  And here we are, at last.
+You're welcome.
 

docs/usage.rst

@@ -1,24 +1,33 @@
 Usage
 =====
-- Forward all traffic::
+
+.. note::
+
+    For information on usage with Windows, see the :doc:`windows` section.
+    For information on using the TProxy method, see the :doc:`tproxy` section.
+
+Forward all traffic::
 
     sshuttle -r username@sshserver 0.0.0.0/0
 
+- Use the :option:`sshuttle -r` parameter to specify a remote server.
+
 - By default sshuttle will automatically choose a method to use. Override with
-  the ``--method=`` parameter.
+  the :option:`sshuttle --method` parameter.
 
 - There is a shortcut for 0.0.0.0/0 for those that value
   their wrists::
 
       sshuttle -r username@sshserver 0/0
 
-- If you would also like your DNS queries to be proxied
-  through the DNS server of the server you are connect to::
+If you would also like your DNS queries to be proxied
+through the DNS server of the server you are connect to::
 
   sshuttle --dns -r username@sshserver 0/0
 
-  The above is probably what you want to use to prevent
-  local network attacks such as Firesheep and friends.
+The above is probably what you want to use to prevent
+local network attacks such as Firesheep and friends.
+See the documentation for the :option:`sshuttle --dns` parameter.
 
 (You may be prompted for one or more passwords; first, the local password to
 become root using sudo, and then the remote ssh password.  Or you might have
@@ -51,45 +60,3 @@ the data back and forth through ssh.
 Fun, right?  A poor man's instant VPN, and you don't even have to have
 admin access on the server.
 
-Additional information for TPROXY
----------------------------------
-TPROXY is the only method that supports full support of IPv6 and UDP.
-
-There are some things you need to consider for TPROXY to work:
-
-- The following commands need to be run first as root. This only needs to be
-  done once after booting up::
-
-      ip route add local default dev lo table 100
-      ip rule add fwmark 1 lookup 100
-      ip -6 route add local default dev lo table 100
-      ip -6 rule add fwmark 1 lookup 100
-
-- The ``--auto-nets`` feature does not detect IPv6 routes automatically. Add IPv6
-  routes manually. e.g. by adding ``'::/0'`` to the end of the command line.
-
-- The client needs to be run as root. e.g.::
-
-      sudo SSH_AUTH_SOCK="$SSH_AUTH_SOCK" $HOME/tree/sshuttle.tproxy/sshuttle  --method=tproxy ...
-
-- You may need to exclude the IP address of the server you are connecting to.
-  Otherwise sshuttle may attempt to intercept the ssh packets, which will not
-  work. Use the ``--exclude`` parameter for this.
-
-- Similarly, UDP return packets (including DNS) could get intercepted and
-  bounced back. This is the case if you have a broad subnet such as
-  ``0.0.0.0/0`` or ``::/0`` that includes the IP address of the client. Use the
-  ``--exclude`` parameter for this.
-
-- You need the ``--method=tproxy`` parameter, as above.
-
-- The routes for the outgoing packets must already exist. For example, if your
-  connection does not have IPv6 support, no IPv6 routes will exist, IPv6
-  packets will not be generated and sshuttle cannot intercept them::
-
-      telnet -6 www.google.com 80
-      Trying 2404:6800:4001:805::1010...
-      telnet: Unable to connect to remote host: Network is unreachable
-
-  Add some dummy routes to external interfaces. Make sure they get removed
-  however after sshuttle exits.

docs/windows.rst

@@ -0,0 +1,19 @@
+Microsoft Windows
+=================
+Currently there is no built in support for running sshuttle directly on
+Microsoft Windows.
+
+What we can really do is to create a Linux VM with Vagrant (or simply
+Virtualbox if you like). In the Vagrant settings, remember to turn on bridged
+NIC. Then, run sshuttle inside the VM like below::
+
+    sshuttle -l 0.0.0.0 -x 10.0.0.0/8 -x 192.168.0.0/16 0/0
+
+10.0.0.0/8 excludes NAT traffic of Vagrant and 192.168.0.0/16 excludes
+traffic to local area network (assuming that we're using 192.168.0.0 subnet).
+
+Assuming the VM has the IP 192.168.1.200 obtained on the bridge NIC (we can
+configure that in Vagrant), we can then ask Windows to route all its traffic
+via the VM by running the following in cmd.exe with admin right::
+
+     route add 0.0.0.0 mask 0.0.0.0 192.168.1.200

run

@@ -1,6 +1,6 @@
 #!/bin/sh
 if python3.5 -V 2>/dev/null; then
-	exec python3 -m "sshuttle" "$@"
+	exec python3.5 -m "sshuttle" "$@"
 else
 	exec python -m "sshuttle" "$@"
 fi

sshuttle/client.py

@@ -95,16 +95,21 @@ def daemon_cleanup():
 class MultiListener:
 
     def __init__(self, type=socket.SOCK_STREAM, proto=0):
-        self.v6 = socket.socket(socket.AF_INET6, type, proto)
-        self.v4 = socket.socket(socket.AF_INET, type, proto)
+        self.type = type
+        self.proto = proto
+        self.v6 = None
+        self.v4 = None
+        self.bind_called = False
 
     def setsockopt(self, level, optname, value):
+        assert(self.bind_called)
         if self.v6:
             self.v6.setsockopt(level, optname, value)
         if self.v4:
             self.v4.setsockopt(level, optname, value)
 
     def add_handler(self, handlers, callback, method, mux):
+        assert(self.bind_called)
         socks = []
         if self.v6:
             socks.append(self.v6)
@@ -119,6 +124,7 @@ class MultiListener:
         )
 
     def listen(self, backlog):
+        assert(self.bind_called)
         if self.v6:
             self.v6.listen(backlog)
         if self.v4:
@@ -133,16 +139,23 @@ class MultiListener:
                     raise e
 
     def bind(self, address_v6, address_v4):
-        if address_v6 and self.v6:
+        assert(not self.bind_called)
+        self.bind_called = True
+        if address_v6 is not None:
+            self.v6 = socket.socket(socket.AF_INET6, self.type, self.proto)
+            self.v6.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
             self.v6.bind(address_v6)
         else:
             self.v6 = None
-        if address_v4 and self.v4:
+        if address_v4 is not None:
+            self.v4 = socket.socket(socket.AF_INET, self.type, self.proto)
+            self.v4.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
             self.v4.bind(address_v4)
         else:
             self.v4 = None
 
     def print_listening(self, what):
+        assert(self.bind_called)
         if self.v6:
             listenip = self.v6.getsockname()
             debug1('%s listening on %r.\n' % (what, listenip))
@@ -569,11 +582,9 @@ def main(listenip_v6, listenip_v4,
     for port in ports:
         debug2(' %d' % port)
         tcp_listener = MultiListener()
-        tcp_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 
         if required.udp:
             udp_listener = MultiListener(socket.SOCK_DGRAM)
-            udp_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         else:
             udp_listener = None
 

sshuttle/methods/pf.py

@@ -11,6 +11,317 @@ from sshuttle.helpers import debug1, debug2, debug3, Fatal, family_to_string
 from sshuttle.methods import BaseMethod
 
 
+_pf_context = {'started_by_sshuttle': False, 'Xtoken': None}
+_pf_fd = None
+
+
+class Generic(object):
+    MAXPATHLEN = 1024
+    PF_CHANGE_ADD_TAIL = 2
+    PF_CHANGE_GET_TICKET = 6
+    PF_PASS = 0
+    PF_RDR = 8
+    PF_OUT = 2
+    ACTION_OFFSET = 0
+    POOL_TICKET_OFFSET = 8
+    ANCHOR_CALL_OFFSET = 1040
+
+    class pf_addr(Structure):
+        class _pfa(Union):
+             _fields_ = [("v4", c_uint32),     # struct in_addr
+                        ("v6", c_uint32 * 4),  # struct in6_addr
+                        ("addr8", c_uint8 * 16),
+                        ("addr16", c_uint16 * 8),
+                        ("addr32", c_uint32 * 4)]
+
+        _fields_ = [("pfa", _pfa)]
+        _anonymous_ = ("pfa",)
+
+    def __init__(self):
+        self.status = b''
+        self.pfioc_pooladdr = c_char * 1136
+
+        self.DIOCNATLOOK = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_natlook) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (23))
+        self.DIOCCHANGERULE = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_rule) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (26))
+        self.DIOCBEGINADDRS = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_pooladdr) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (51))
+
+    def enable(self):
+        if b'INFO:\nStatus: Disabled' in self.status:
+            pfctl('-e')
+            _pf_context['started_by_sshuttle'] = True
+
+    def disable(self):
+        if _pf_context['started_by_sshuttle']:
+            pfctl('-d')
+
+    def query_nat(self, family, proto, src_ip, src_port, dst_ip, dst_port):
+        [proto, family, src_port, dst_port] = [
+            int(v) for v in [proto, family, src_port, dst_port]]
+
+        packed_src_ip = socket.inet_pton(family, src_ip)
+        packed_dst_ip = socket.inet_pton(family, dst_ip)
+
+        assert len(packed_src_ip) == len(packed_dst_ip)
+        length = len(packed_src_ip)
+
+        pnl = self.pfioc_natlook()
+        pnl.proto = proto
+        pnl.direction = self.PF_OUT
+        pnl.af = family
+        memmove(addressof(pnl.saddr), packed_src_ip, length)
+        memmove(addressof(pnl.daddr), packed_dst_ip, length)
+        self._add_natlook_ports(pnl, src_port, dst_port)
+
+        ioctl(pf_get_dev(), self.DIOCNATLOOK,
+              (c_char * sizeof(pnl)).from_address(addressof(pnl)))
+
+        ip = socket.inet_ntop(
+            pnl.af, (c_char * length).from_address(addressof(pnl.rdaddr)).raw)
+        port = socket.ntohs(self._get_natlook_port(pnl.rdxport))
+        return (ip, port)
+
+    def _add_natlook_ports(self, pnl, src_port, dst_port):
+        pnl.sxport = socket.htons(src_port)
+        pnl.dxport = socket.htons(dst_port)
+
+    def _get_natlook_port(self, xport):
+        return xport
+
+    def add_anchors(self, status=None):
+        if status is None:
+            status = pfctl('-s all')[0]
+        self.status = status
+        if b'\nanchor "sshuttle"' not in status:
+            self._add_anchor_rule(self.PF_PASS, b"sshuttle")
+
+    def _add_anchor_rule(self, type, name, pr=None):
+        if pr is None:
+            pr = self.pfioc_rule()
+
+        memmove(addressof(pr) + self.ANCHOR_CALL_OFFSET, name,
+                min(self.MAXPATHLEN, len(name)))  # anchor_call = name
+        memmove(addressof(pr) + self.RULE_ACTION_OFFSET,
+                struct.pack('I', type), 4)  # rule.action = type
+
+        memmove(addressof(pr) + self.ACTION_OFFSET, struct.pack(
+            'I', self.PF_CHANGE_GET_TICKET), 4)  # action = PF_CHANGE_GET_TICKET
+        ioctl(pf_get_dev(), pf.DIOCCHANGERULE, pr)
+
+        memmove(addressof(pr) + self.ACTION_OFFSET, struct.pack(
+            'I', self.PF_CHANGE_ADD_TAIL), 4)  # action = PF_CHANGE_ADD_TAIL
+        ioctl(pf_get_dev(), pf.DIOCCHANGERULE, pr)
+
+    def add_rules(self, rules):
+        assert isinstance(rules, bytes)
+        debug3("rules:\n" + rules.decode("ASCII"))
+        pfctl('-a sshuttle -f /dev/stdin', rules)
+
+
+class FreeBsd(Generic):
+    RULE_ACTION_OFFSET = 2968
+
+    def __new__(cls):
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("sxport", c_uint16),
+                        ("dxport", c_uint16),
+                        ("rsxport", c_uint16),
+                        ("rdxport", c_uint16),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        freebsd = Generic.__new__(cls)
+        freebsd.pfioc_rule = c_char * 3040
+        freebsd.pfioc_natlook = pfioc_natlook
+        return freebsd
+
+    def __init__(self):
+        super(FreeBsd, self).__init__()
+
+    def add_anchors(self):
+        status = pfctl('-s all')[0]
+        if b'\nrdr-anchor "sshuttle"' not in status:
+            self._add_anchor_rule(self.PF_RDR, b'sshuttle')
+        super(FreeBsd, self).add_anchors(status=status)
+
+    def _add_anchor_rule(self, type, name):
+        pr = self.pfioc_rule()
+        ppa = self.pfioc_pooladdr()
+
+        ioctl(pf_get_dev(), self.DIOCBEGINADDRS, ppa)
+        # pool ticket
+        memmove(addressof(pr) + self.POOL_TICKET_OFFSET, ppa[4:8], 4)
+        super(FreeBsd, self)._add_anchor_rule(type, name, pr=pr)
+
+    def add_rules(self, includes, port, dnsport, nslist):
+        tables = [
+            b'table <forward_subnets> {%s}' % b','.join(includes)
+        ]
+        translating_rules = [
+            b'rdr pass on lo0 proto tcp '
+            b'to <forward_subnets> -> 127.0.0.1 port %r' % port
+        ]
+        filtering_rules = [
+            b'pass out route-to lo0 inet proto tcp '
+            b'to <forward_subnets> keep state'
+        ]
+
+        if len(nslist) > 0:
+            tables.append(
+                b'table <dns_servers> {%s}' %
+                b','.join([ns[1].encode("ASCII") for ns in nslist]))
+            translating_rules.append(
+                b'rdr pass on lo0 proto udp to '
+                b'<dns_servers> port 53 -> 127.0.0.1 port %r' % dnsport)
+            filtering_rules.append(
+                b'pass out route-to lo0 inet proto udp to '
+                b'<dns_servers> port 53 keep state')
+
+        rules = b'\n'.join(tables + translating_rules + filtering_rules) \
+                + b'\n'
+
+        super(FreeBsd, self).add_rules(rules)
+
+
+class OpenBsd(Generic):
+    POOL_TICKET_OFFSET = 4
+    RULE_ACTION_OFFSET = 3324
+    ANCHOR_CALL_OFFSET = 1036
+
+    def __init__(self):
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("rdomain", c_uint16),
+                        ("rrdomain", c_uint16),
+                        ("sxport", c_uint16),
+                        ("dxport", c_uint16),
+                        ("rsxport", c_uint16),
+                        ("rdxport", c_uint16),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        self.pfioc_rule = c_char * 3400
+        self.pfioc_natlook = pfioc_natlook
+        super(OpenBsd, self).__init__()
+
+    def add_anchors(self):
+        # before adding anchors and rules we must override the skip lo
+        # that comes by default in openbsd pf.conf so the rules we will add,
+        # which rely on translating/filtering  packets on lo, can work
+        pfctl('-f /dev/stdin', b'match on lo\n')
+        super(OpenBsd, self).add_anchors()
+
+    def add_rules(self, includes, port, dnsport, nslist):
+        tables = [
+            b'table <forward_subnets> {%s}' % b','.join(includes)
+        ]
+        translating_rules = [
+            b'pass in on lo0 inet proto tcp '
+            b'divert-to 127.0.0.1 port %r' % port
+        ]
+        filtering_rules = [
+            b'pass out inet proto tcp '
+            b'to <forward_subnets> route-to lo0 keep state'
+        ]
+
+        if len(nslist) > 0:
+            tables.append(
+                b'table <dns_servers> {%s}' %
+                b','.join([ns[1].encode("ASCII") for ns in nslist]))
+            translating_rules.append(
+                b'pass in on lo0 inet proto udp to <dns_servers>'
+                b'port 53 rdr-to 127.0.0.1 port %r' % dnsport)
+            filtering_rules.append(
+                b'pass out inet proto udp to '
+                b'<dns_servers> port 53 route-to lo0 keep state')
+
+        rules = b'\n'.join(tables + translating_rules + filtering_rules) \
+                + b'\n'
+
+        super(OpenBsd, self).add_rules(rules)
+
+
+class Darwin(FreeBsd):
+    RULE_ACTION_OFFSET = 3068
+
+    def __init__(self):
+        class pf_state_xport(Union):
+            _fields_ = [("port", c_uint16),
+                        ("call_id", c_uint16),
+                        ("spi", c_uint32)]
+
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("sxport", pf_state_xport),
+                        ("dxport", pf_state_xport),
+                        ("rsxport", pf_state_xport),
+                        ("rdxport", pf_state_xport),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        self.pfioc_rule = c_char * 3104
+        self.pfioc_natlook = pfioc_natlook
+        super(Darwin, self).__init__()
+
+    def enable(self):
+        o = pfctl('-E')
+        _pf_context['Xtoken'] = \
+            re.search(b'Token : (.+)', o[1]).group(1)
+
+    def disable(self):
+        if _pf_context['Xtoken'] is not None:
+            pfctl('-X %s' % _pf_context['Xtoken'].decode("ASCII"))
+
+    def add_anchors(self):
+        # before adding anchors and rules we must override the skip lo
+        # that in some cases ends up in the chain so the rules we will add,
+        # which rely on translating/filtering  packets on lo, can work
+        pfctl('-f /dev/stdin', b'pass on lo\n')
+        super(Darwin, self).add_anchors()
+
+    def _add_natlook_ports(self, pnl, src_port, dst_port):
+        pnl.sxport.port = socket.htons(src_port)
+        pnl.dxport.port = socket.htons(dst_port)
+
+    def _get_natlook_port(self, xport):
+        return xport.port
+
+
+if sys.platform == 'darwin':
+    pf = Darwin()
+elif sys.platform.startswith('openbsd'):
+    pf = OpenBsd()
+else:
+    pf = FreeBsd()
+
+
 def pfctl(args, stdin=None):
     argv = ['pfctl'] + list(args.split(" "))
     debug1('>> %s\n' % ' '.join(argv))
@@ -24,87 +335,6 @@ def pfctl(args, stdin=None):
 
     return o
 
-_pf_context = {'started_by_sshuttle': False, 'Xtoken': None}
-_pf_fd = None
-
-
-class OsDefs(object):
-
-    def __init__(self, platform=None):
-        if platform is None:
-            platform = sys.platform
-        self.platform = platform
-
-        # This are some classes and functions used to support pf in yosemite.
-        if platform == 'darwin':
-            class pf_state_xport(Union):
-                _fields_ = [("port", c_uint16),
-                            ("call_id", c_uint16),
-                            ("spi", c_uint32)]
-        else:
-            class pf_state_xport(Union):
-                _fields_ = [("port", c_uint16),
-                            ("call_id", c_uint16)]
-
-        class pf_addr(Structure):
-
-            class _pfa(Union):
-                _fields_ = [("v4",            c_uint32),      # struct in_addr
-                            ("v6",            c_uint32 * 4),  # struct in6_addr
-                            ("addr8",         c_uint8 * 16),
-                            ("addr16",        c_uint16 * 8),
-                            ("addr32",        c_uint32 * 4)]
-
-            _fields_ = [("pfa",               _pfa)]
-            _anonymous_ = ("pfa",)
-
-        class pfioc_natlook(Structure):
-            _fields_ = [("saddr", pf_addr),
-                        ("daddr", pf_addr),
-                        ("rsaddr", pf_addr),
-                        ("rdaddr", pf_addr),
-                        ("sxport", pf_state_xport),
-                        ("dxport", pf_state_xport),
-                        ("rsxport", pf_state_xport),
-                        ("rdxport", pf_state_xport),
-                        ("af", c_uint8),                      # sa_family_t
-                        ("proto", c_uint8),
-                        ("proto_variant", c_uint8),
-                        ("direction", c_uint8)]
-        self.pfioc_natlook = pfioc_natlook
-
-        # sizeof(struct pfioc_rule)
-        self.pfioc_rule = c_char * \
-            (3104 if platform == 'darwin' else 3040)
-
-        # sizeof(struct pfioc_pooladdr)
-        self.pfioc_pooladdr = c_char * 1136
-
-        self.MAXPATHLEN = 1024
-
-        self.DIOCNATLOOK = (
-            (0x40000000 | 0x80000000) |
-            ((sizeof(pfioc_natlook) & 0x1fff) << 16) |
-            ((ord('D')) << 8) | (23))
-        self.DIOCCHANGERULE = (
-            (0x40000000 | 0x80000000) |
-            ((sizeof(self.pfioc_rule) & 0x1fff) << 16) |
-            ((ord('D')) << 8) | (26))
-        self.DIOCBEGINADDRS = (
-            (0x40000000 | 0x80000000) |
-            ((sizeof(self.pfioc_pooladdr) & 0x1fff) << 16) |
-            ((ord('D')) << 8) | (51))
-
-        self.PF_CHANGE_ADD_TAIL = 2
-        self.PF_CHANGE_GET_TICKET = 6
-
-        self.PF_PASS = 0
-        self.PF_RDR = 8
-
-        self.PF_OUT = 2
-
-osdefs = OsDefs()
-
 
 def pf_get_dev():
     global _pf_fd
@@ -114,59 +344,6 @@ def pf_get_dev():
     return _pf_fd
 
 
-def pf_query_nat(family, proto, src_ip, src_port, dst_ip, dst_port):
-    [proto, family, src_port, dst_port] = [
-        int(v) for v in [proto, family, src_port, dst_port]]
-
-    packed_src_ip = socket.inet_pton(family, src_ip)
-    packed_dst_ip = socket.inet_pton(family, dst_ip)
-
-    assert len(packed_src_ip) == len(packed_dst_ip)
-    length = len(packed_src_ip)
-
-    pnl = osdefs.pfioc_natlook()
-    pnl.proto = proto
-    pnl.direction = osdefs.PF_OUT
-    pnl.af = family
-    memmove(addressof(pnl.saddr), packed_src_ip, length)
-    memmove(addressof(pnl.daddr), packed_dst_ip, length)
-    pnl.sxport.port = socket.htons(src_port)
-    pnl.dxport.port = socket.htons(dst_port)
-
-    ioctl(pf_get_dev(), osdefs.DIOCNATLOOK,
-          (c_char * sizeof(pnl)).from_address(addressof(pnl)))
-
-    ip = socket.inet_ntop(
-        pnl.af, (c_char * length).from_address(addressof(pnl.rdaddr)).raw)
-    port = socket.ntohs(pnl.rdxport.port)
-    return (ip, port)
-
-
-def pf_add_anchor_rule(type, name):
-    ACTION_OFFSET = 0
-    POOL_TICKET_OFFSET = 8
-    ANCHOR_CALL_OFFSET = 1040
-    RULE_ACTION_OFFSET = 3068 if osdefs.platform == 'darwin' else 2968
-
-    pr = osdefs.pfioc_rule()
-    ppa = osdefs.pfioc_pooladdr()
-
-    ioctl(pf_get_dev(), osdefs.DIOCBEGINADDRS, ppa)
-
-    memmove(addressof(pr) + POOL_TICKET_OFFSET, ppa[4:8], 4)  # pool_ticket
-    memmove(addressof(pr) + ANCHOR_CALL_OFFSET, name,
-            min(osdefs.MAXPATHLEN, len(name)))  # anchor_call = name
-    memmove(addressof(pr) + RULE_ACTION_OFFSET,
-            struct.pack('I', type), 4)  # rule.action = type
-
-    memmove(addressof(pr) + ACTION_OFFSET, struct.pack(
-        'I', osdefs.PF_CHANGE_GET_TICKET), 4)  # action = PF_CHANGE_GET_TICKET
-    ioctl(pf_get_dev(), osdefs.DIOCCHANGERULE, pr)
-
-    memmove(addressof(pr) + ACTION_OFFSET, struct.pack(
-        'I', osdefs.PF_CHANGE_ADD_TAIL), 4)  # action = PF_CHANGE_ADD_TAIL
-    ioctl(pf_get_dev(), osdefs.DIOCCHANGERULE, pr)
-
 
 class Method(BaseMethod):
 
@@ -214,45 +391,9 @@ class Method(BaseMethod):
                                     snet.encode("ASCII"),
                                     swidth))
 
-            tables.append(
-                b'table <forward_subnets> {%s}' % b','.join(includes))
-            translating_rules.append(
-                b'rdr pass on lo0 proto tcp '
-                b'to <forward_subnets> -> 127.0.0.1 port %r' % port)
-            filtering_rules.append(
-                b'pass out route-to lo0 inet proto tcp '
-                b'to <forward_subnets> keep state')
-
-        if len(nslist) > 0:
-            tables.append(
-                b'table <dns_servers> {%s}' %
-                b','.join([ns[1].encode("ASCII") for ns in nslist]))
-            translating_rules.append(
-                b'rdr pass on lo0 proto udp to '
-                b'<dns_servers> port 53 -> 127.0.0.1 port %r' % dnsport)
-            filtering_rules.append(
-                b'pass out route-to lo0 inet proto udp to '
-                b'<dns_servers> port 53 keep state')
-
-        rules = b'\n'.join(tables + translating_rules + filtering_rules) \
-                + b'\n'
-        assert isinstance(rules, bytes)
-        debug3("rules:\n" + rules.decode("ASCII"))
-
-        pf_status = pfctl('-s all')[0]
-        if b'\nrdr-anchor "sshuttle" all\n' not in pf_status:
-            pf_add_anchor_rule(osdefs.PF_RDR, b"sshuttle")
-        if b'\nanchor "sshuttle" all\n' not in pf_status:
-            pf_add_anchor_rule(osdefs.PF_PASS, b"sshuttle")
-
-        pfctl('-a sshuttle -f /dev/stdin', rules)
-        if osdefs.platform == "darwin":
-            o = pfctl('-E')
-            _pf_context['Xtoken'] = \
-                re.search(b'Token : (.+)', o[1]).group(1)
-        elif b'INFO:\nStatus: Disabled' in pf_status:
-            pfctl('-e')
-            _pf_context['started_by_sshuttle'] = True
+        pf.add_anchors()
+        pf.add_rules(includes, port, dnsport, nslist)
+        pf.enable()
 
     def restore_firewall(self, port, family, udp):
         if family != socket.AF_INET:
@@ -263,16 +404,12 @@ class Method(BaseMethod):
             raise Exception("UDP not supported by pf method_name")
 
         pfctl('-a sshuttle -F all')
-        if osdefs.platform == "darwin":
-            if _pf_context['Xtoken'] is not None:
-                pfctl('-X %s' % _pf_context['Xtoken'].decode("ASCII"))
-        elif _pf_context['started_by_sshuttle']:
-            pfctl('-d')
+        pf.disable()
 
     def firewall_command(self, line):
         if line.startswith('QUERY_PF_NAT '):
             try:
-                dst = pf_query_nat(*(line[13:].split(',')))
+                dst = pf.query_nat(*(line[13:].split(',')))
                 sys.stdout.write('QUERY_PF_NAT_SUCCESS %s,%r\n' % dst)
             except IOError as e:
                 sys.stdout.write('QUERY_PF_NAT_FAILURE %s\n' % e)

sshuttle/server.py

@@ -257,7 +257,7 @@ def main(latency_control):
             if lines[-1]:
                 # no terminating newline: entry isn't complete yet!
                 hw.leftover = lines.pop()
-                lines.append('')
+                lines.append(b'')
             else:
                 hw.leftover = b''
             mux.send(0, ssnet.CMD_HOST_LIST, b'\n'.join(lines))

sshuttle/tests/test_methods_pf.py

@@ -4,7 +4,7 @@ import socket
 
 from sshuttle.methods import get_method
 from sshuttle.helpers import Fatal
-from sshuttle.methods.pf import OsDefs
+from sshuttle.methods.pf import FreeBsd, Darwin, OpenBsd
 
 
 def test_get_supported_features():
@@ -85,7 +85,7 @@ def test_assert_features():
         method.assert_features(features)
 
 
-@patch('sshuttle.methods.pf.osdefs', OsDefs('darwin'))
+@patch('sshuttle.methods.pf.pf', Darwin())
 @patch('sshuttle.methods.pf.sys.stdout')
 @patch('sshuttle.methods.pf.ioctl')
 @patch('sshuttle.methods.pf.pf_get_dev')
@@ -108,11 +108,11 @@ def test_firewall_command_darwin(mock_pf_get_dev, mock_ioctl, mock_stdout):
     ]
 
 
-@patch('sshuttle.methods.pf.osdefs', OsDefs('notdarwin'))
+@patch('sshuttle.methods.pf.pf', FreeBsd())
 @patch('sshuttle.methods.pf.sys.stdout')
 @patch('sshuttle.methods.pf.ioctl')
 @patch('sshuttle.methods.pf.pf_get_dev')
-def test_firewall_command_notdarwin(mock_pf_get_dev, mock_ioctl, mock_stdout):
+def test_firewall_command_freebsd(mock_pf_get_dev, mock_ioctl, mock_stdout):
     method = get_method('pf')
     assert not method.firewall_command("somthing")
 
@@ -131,6 +131,29 @@ def test_firewall_command_notdarwin(mock_pf_get_dev, mock_ioctl, mock_stdout):
     ]
 
 
+@patch('sshuttle.methods.pf.pf', OpenBsd())
+@patch('sshuttle.methods.pf.sys.stdout')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_firewall_command_openbsd(mock_pf_get_dev, mock_ioctl, mock_stdout):
+    method = get_method('pf')
+    assert not method.firewall_command("somthing")
+
+    command = "QUERY_PF_NAT %d,%d,%s,%d,%s,%d\n" % (
+        socket.AF_INET, socket.IPPROTO_TCP,
+        "127.0.0.1", 1025, "127.0.0.2", 1024)
+    assert method.firewall_command(command)
+
+    assert mock_pf_get_dev.mock_calls == [call()]
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xc0504417, ANY),
+    ]
+    assert mock_stdout.mock_calls == [
+        call.write('QUERY_PF_NAT_SUCCESS 0.0.0.0,0\n'),
+        call.flush(),
+    ]
+
+
 def pfctl(args, stdin=None):
     if args == '-s all':
         return (b'INFO:\nStatus: Disabled\nanother mary had a little lamb\n',
@@ -141,7 +164,7 @@ def pfctl(args, stdin=None):
 
 
 @patch('sshuttle.helpers.verbose', new=3)
-@patch('sshuttle.methods.pf.osdefs', OsDefs('darwin'))
+@patch('sshuttle.methods.pf.pf', Darwin())
 @patch('sshuttle.methods.pf.pfctl')
 @patch('sshuttle.methods.pf.ioctl')
 @patch('sshuttle.methods.pf.pf_get_dev')
@@ -192,6 +215,7 @@ def test_setup_firewall_darwin(mock_pf_get_dev, mock_ioctl, mock_pfctl):
         call(mock_pf_get_dev(), 0xCC20441A, ANY),
     ]
     assert mock_pfctl.mock_calls == [
+        call('-f /dev/stdin', b'pass on lo\n'),
         call('-s all'),
         call('-a sshuttle -f /dev/stdin',
              b'table <forward_subnets> {!1.2.3.66/32,1.2.3.0/24}\n'
@@ -222,11 +246,11 @@ def test_setup_firewall_darwin(mock_pf_get_dev, mock_ioctl, mock_pfctl):
 
 
 @patch('sshuttle.helpers.verbose', new=3)
-@patch('sshuttle.methods.pf.osdefs', OsDefs('notdarwin'))
+@patch('sshuttle.methods.pf.pf', FreeBsd())
 @patch('sshuttle.methods.pf.pfctl')
 @patch('sshuttle.methods.pf.ioctl')
 @patch('sshuttle.methods.pf.pf_get_dev')
-def test_setup_firewall_notdarwin(mock_pf_get_dev, mock_ioctl, mock_pfctl):
+def test_setup_firewall_freebsd(mock_pf_get_dev, mock_ioctl, mock_pfctl):
     mock_pfctl.side_effect = pfctl
 
     method = get_method('pf')
@@ -300,3 +324,80 @@ def test_setup_firewall_notdarwin(mock_pf_get_dev, mock_ioctl, mock_pfctl):
     mock_pf_get_dev.reset_mock()
     mock_pfctl.reset_mock()
     mock_ioctl.reset_mock()
+
+
+@patch('sshuttle.helpers.verbose', new=3)
+@patch('sshuttle.methods.pf.pf', OpenBsd())
+@patch('sshuttle.methods.pf.pfctl')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_setup_firewall_openbsd(mock_pf_get_dev, mock_ioctl, mock_pfctl):
+    mock_pfctl.side_effect = pfctl
+
+    method = get_method('pf')
+    assert method.name == 'pf'
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1024, 1026,
+            [(10, u'2404:6800:4004:80c::33')],
+            10,
+            [(10, 64, False, u'2404:6800:4004:80c::'),
+                (10, 128, True, u'2404:6800:4004:80c::101f')],
+            True)
+    assert str(excinfo.value) \
+        == 'Address family "AF_INET6" unsupported by pf method_name'
+    assert mock_pf_get_dev.mock_calls == []
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == []
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(2, u'1.2.3.33')],
+            2,
+            [(2, 24, False, u'1.2.3.0'), (2, 32, True, u'1.2.3.66')],
+            True)
+    assert str(excinfo.value) == 'UDP not supported by pf method_name'
+    assert mock_pf_get_dev.mock_calls == []
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(2, u'1.2.3.33')],
+        2,
+        [(2, 24, False, u'1.2.3.0'), (2, 32, True, u'1.2.3.66')],
+        False)
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xcd48441a, ANY),
+        call(mock_pf_get_dev(), 0xcd48441a, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-f /dev/stdin', b'match on lo\n'),
+        call('-s all'),
+        call('-a sshuttle -f /dev/stdin',
+             b'table <forward_subnets> {!1.2.3.66/32,1.2.3.0/24}\n'
+             b'table <dns_servers> {1.2.3.33}\n'
+             b'pass in on lo0 inet proto tcp divert-to 127.0.0.1 port 1025\n'
+             b'pass in on lo0 inet proto udp to '
+             b'<dns_servers>port 53 rdr-to 127.0.0.1 port 1027\n'
+             b'pass out inet proto tcp to '
+             b'<forward_subnets> route-to lo0 keep state\n'
+             b'pass out inet proto udp to '
+             b'<dns_servers> port 53 route-to lo0 keep state\n'),
+        call('-e'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    method.restore_firewall(1025, 2, False)
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == [
+        call('-a sshuttle -F all'),
+        call("-d"),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_pfctl.reset_mock()
+    mock_ioctl.reset_mock()