Keep track of address family address belongs too.

client.py

@@ -180,10 +180,10 @@ class FirewallClient:
 
     def start(self):
         self.pfile.write('ROUTES\n')
-        for (ip,width) in self.subnets_include+self.auto_nets:
-            self.pfile.write('%d,0,%s\n' % (width, ip))
-        for (ip,width) in self.subnets_exclude:
-            self.pfile.write('%d,1,%s\n' % (width, ip))
+        for (family,ip,width) in self.subnets_include+self.auto_nets:
+            self.pfile.write('%d,%d,0,%s\n' % (family, width, ip))
+        for (family,ip,width) in self.subnets_exclude:
+            self.pfile.write('%d,%d,1,%s\n' % (family, width, ip))
         self.pfile.write('GO\n')
         self.pfile.flush()
         line = self.pfile.readline()
@@ -234,7 +234,7 @@ def onaccept_tcp(listener, mux, handlers):
     dstip = original_dst(sock)
     debug1('Accept: %s:%r -> %s:%r.\n' % (srcip[0],srcip[1],
                                           dstip[0],dstip[1]))
-    if dstip[1] == listener.getsockname()[1] and islocal(dstip[0]):
+    if dstip[1] == listener.getsockname()[1] and islocal(dstip[0], sock.family):
         debug1("-- ignored: that's my address!\n")
         sock.close()
         return
@@ -243,7 +243,7 @@ def onaccept_tcp(listener, mux, handlers):
         log('warning: too many open channels.  Discarded connection.\n')
         sock.close()
         return
-    mux.send(chan, ssnet.CMD_TCP_CONNECT, '%s,%s' % dstip)
+    mux.send(chan, ssnet.CMD_TCP_CONNECT, '%d,%s,%s' % (sock.family, dstip[0], dstip[1]))
     outwrap = MuxWrapper(mux, chan)
     handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
     expire_connections(time.time(), mux)
@@ -329,8 +329,8 @@ def _main(tcp_listener, fw, ssh_cmd, remotename, python, latency_control,
     def onroutes(routestr):
         if auto_nets:
             for line in routestr.strip().split('\n'):
-                (ip,width) = line.split(',', 1)
-                fw.auto_nets.append((ip,int(width)))
+                (family,ip,width) = line.split(',', 2)
+                fw.auto_nets.append((family,ip,int(width)))
 
         # we definitely want to do this *after* starting ssh, or we might end
         # up intercepting the ssh connection!

firewall.py

@@ -14,8 +14,12 @@ def nonfatal(func, *args):
         log('error: %s\n' % e)
 
 
-def ipt_chain_exists(name):
-    argv = ['iptables', '-t', 'nat', '-nL']
+def ipt_chain_exists(family, name):
+    if family == socket.AF_INET:
+        cmd = 'iptables'
+    else:
+        raise Exception('Unsupported family "%s"'%family_to_string(family))
+    argv = [cmd, '-t', 'nat', '-nL']
     p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
     for line in p.stdout:
         if line.startswith('Chain %s ' % name):
@@ -25,8 +29,11 @@ def ipt_chain_exists(name):
         raise Fatal('%r returned %d' % (argv, rv))
 
 
-def ipt(*args):
-    argv = ['iptables', '-t', 'nat'] + list(args)
+def _ipt(family, *args):
+    if family == socket.AF_INET:
+        argv = ['iptables', '-t', 'nat'] + list(args)
+    else:
+        raise Exception('Unsupported family "%s"'%family_to_string(family))
     debug1('>> %s\n' % ' '.join(argv))
     rv = ssubprocess.call(argv)
     if rv:
@@ -34,7 +41,7 @@ def ipt(*args):
 
 
 _no_ttl_module = False
-def ipt_ttl(*args):
+def _ipt_ttl(family, *args):
     global _no_ttl_module
     if not _no_ttl_module:
         # we avoid infinite loops by generating server-side connections
@@ -42,16 +49,15 @@ def ipt_ttl(*args):
         # connections, in case client == server.
         try:
             argsplus = list(args) + ['-m', 'ttl', '!', '--ttl', '42']
-            ipt(*argsplus)
+            _ipt(family, *argsplus)
         except Fatal:
-            ipt(*args)
+            _ipt(family, *args)
             # we only get here if the non-ttl attempt succeeds
             log('sshuttle: warning: your iptables is missing '
                 'the ttl module.\n')
             _no_ttl_module = True
     else:
-        ipt(*args)
-
+        _ipt(family, *args)
 
 
 # We name the chain based on the transproxy port number so that it's possible
@@ -59,11 +65,20 @@ def ipt_ttl(*args):
 # multiple copies shouldn't have overlapping subnets, or only the most-
 # recently-started one will win (because we use "-I OUTPUT 1" instead of
 # "-A OUTPUT").
-def do_iptables(port, dnsport, subnets):
+def do_iptables(port, dnsport, family, subnets):
+    # only ipv4 supported with NAT
+    if family != socket.AF_INET:
+        raise Exception('Address family "%s" unsupported by nat method'%family_to_string(family))
+
+    def ipt(*args):
+        return _ipt(family, *args)
+    def ipt_ttl(*args):
+        return _ipt_ttl(family, *args)
+
     chain = 'sshuttle-%s' % port
 
     # basic cleanup/setup of chains
-    if ipt_chain_exists(chain):
+    if ipt_chain_exists(family, chain):
         nonfatal(ipt, '-D', 'OUTPUT', '-j', chain)
         nonfatal(ipt, '-D', 'PREROUTING', '-j', chain)
         nonfatal(ipt, '-F', chain)
@@ -81,7 +96,7 @@ def do_iptables(port, dnsport, subnets):
         # to least-specific, and at any given level of specificity, we want
         # excludes to come first.  That's why the columns are in such a non-
         # intuitive order.
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
+        for f,swidth,sexclude,snet in sorted(subnets, key=lambda s: s[1], reverse=True):
             if sexclude:
                 ipt('-A', chain, '-j', 'RETURN',
                     '--dest', '%s/%s' % (snet,swidth),
@@ -207,7 +222,11 @@ def ipfw(*args):
         raise Fatal('%r returned %d' % (argv, rv))
 
 
-def do_ipfw(port, dnsport, subnets):
+def do_ipfw(port, dnsport, family, subnets):
+    # IPv6 not supported
+    if family not in [socket.AF_INET, ]:
+        raise Exception('Address family "%s" unsupported by ipfw method'%family_to_string(family))
+
     sport = str(port)
     xsport = str(port+1)
 
@@ -240,7 +259,7 @@ def do_ipfw(port, dnsport, subnets):
 
     if subnets:
         # create new subnet entries
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
+        for f,swidth,sexclude,snet in sorted(subnets, key=lambda s: s[1], reverse=True):
             if sexclude:
                 ipfw('add', sport, 'skipto', xsport,
                      'log', 'tcp',
@@ -419,15 +438,21 @@ def main(port, dnsport, syslog):
         elif line == 'GO\n':
             break
         try:
-            (width,exclude,ip) = line.strip().split(',', 2)
+            (family,width,exclude,ip) = line.strip().split(',', 3)
         except:
             raise Fatal('firewall: expected route or GO but got %r' % line)
-        subnets.append((int(width), bool(int(exclude)), ip))
+        subnets.append((int(family), int(width), bool(int(exclude)), ip))
         
     try:
         if line:
             debug1('firewall manager: starting transproxy.\n')
-            do_wait = do_it(port, dnsport, subnets)
+
+            subnets_v4 = filter(lambda i: i[0]==socket.AF_INET, subnets)
+            if port:
+                do_wait = do_it(port, dnsport, socket.AF_INET, subnets_v4)
+            elif len(subnets_v4) > 0:
+                debug1('IPv4 subnets defined but IPv4 disabled\n')
+
             sys.stdout.write('STARTED\n')
         
         try:
@@ -456,5 +481,6 @@ def main(port, dnsport, syslog):
             debug1('firewall manager: undoing changes.\n')
         except:
             pass
-        do_it(port, 0, [])
+        if port:
+            do_it(port, 0, socket.AF_INET, [])
         restore_etc_hosts(port)

helpers.py

@@ -58,8 +58,8 @@ def resolvconf_random_nameserver():
         return '127.0.0.1'
     
 
-def islocal(ip):
-    sock = socket.socket()
+def islocal(ip,family):
+    sock = socket.socket(family)
     try:
         try:
             sock.bind((ip, 0))
@@ -73,3 +73,11 @@ def islocal(ip):
     return True  # it's a local IP, or there would have been an error
 
 
+def family_to_string(family):
+    if family == socket.AF_INET6:
+        return "AF_INET6"
+    elif family == socket.AF_INET:
+        return "AF_INET"
+    else:
+        return str(family)
+

main.py

-import sys, os, re
+import sys, os, re, socket
 import helpers, options, client, server, firewall, hostwatch
 import compat.ssubprocess as ssubprocess
 from helpers import *
@@ -22,7 +22,7 @@ def parse_subnets(subnets_str):
             raise Fatal('%d.%d.%d.%d has numbers > 255' % (a,b,c,d))
         if width > 32:
             raise Fatal('*/%d is greater than the maximum of 32' % width)
-        subnets.append(('%d.%d.%d.%d' % (a,b,c,d), width))
+        subnets.append((socket.AF_INET, '%d.%d.%d.%d' % (a,b,c,d), width))
     return subnets
 
 

server.py

@@ -59,7 +59,7 @@ def _list_routes():
         mask = _maskbits(maskw)   # returns 32 if maskw is null
         width = min(ipw[1], mask)
         ip = ipw[0] & _shl(_shl(1, width) - 1, 32-width)
-        routes.append((socket.inet_ntoa(struct.pack('!I', ip)), width))
+        routes.append((socket.AF_INET, socket.inet_ntoa(struct.pack('!I', ip)), width))
     rv = p.wait()
     if rv != 0:
         log('WARNING: %r returned %d\n' % (argv, rv))
@@ -68,9 +68,9 @@ def _list_routes():
 
 
 def list_routes():
-    for (ip,width) in _list_routes():
+    for (family, ip,width) in _list_routes():
         if not ip.startswith('0.') and not ip.startswith('127.'):
-            yield (ip,width)
+            yield (family, ip,width)
 
 
 def _exc_dump():
@@ -170,7 +170,7 @@ def main():
     routes = list(list_routes())
     debug1('available routes:\n')
     for r in routes:
-        debug1('  %s/%d\n' % r)
+        debug1('  %d/%s/%d\n' % r)
         
     # synchronization header
     sys.stdout.write('\0\0SSHUTTLE0001')
@@ -184,7 +184,7 @@ def main():
     handlers.append(mux)
     routepkt = ''
     for r in routes:
-        routepkt += '%s,%d\n' % r
+        routepkt += '%d,%s,%d\n' % r
     mux.send(0, ssnet.CMD_ROUTES, routepkt)
 
     hw = Hostwatch()
@@ -213,9 +213,10 @@ def main():
     mux.got_host_req = got_host_req
 
     def new_channel(channel, data):
-        (dstip,dstport) = data.split(',', 1)
+        (family,dstip,dstport) = data.split(',', 2)
+        family = int(family)
         dstport = int(dstport)
-        outwrap = ssnet.connect_dst(dstip,dstport)
+        outwrap = ssnet.connect_dst(family, dstip, dstport)
         handlers.append(Proxy(MuxWrapper(mux, channel), outwrap))
     mux.new_channel = new_channel
 

ssnet.py

@@ -523,9 +523,9 @@ class MuxWrapper(SockWrapper):
                             % (cmd, len(data)))
 
 
-def connect_dst(ip, port):
+def connect_dst(family, ip, port):
     debug2('Connecting to %s:%d\n' % (ip, port))
-    outsock = socket.socket()
+    outsock = socket.socket(family)
     outsock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
     return SockWrapper(outsock, outsock,
                        connect_to = (ip,port),