TProxy IPv6 support.

client.py

@@ -99,41 +99,55 @@ def original_dst(sock):
 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)
 
     def setsockopt(self, level, optname, value):
+        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):
+        if self.v6:
+            handlers.append(Handler([self.v6], lambda: callback(self.v6, method, mux, handlers)))
         if self.v4:
             handlers.append(Handler([self.v4], lambda: callback(self.v4, method, mux, handlers)))
 
     def listen(self, backlog):
+        if self.v6:
+            self.v6.listen(backlog)
         if self.v4:
             self.v4.listen(backlog)
 
-    def bind(self, address_v4):
+    def bind(self, address_v6, address_v4):
+        if address_v6 and self.v6:
+            self.v6.bind(address_v6)
+        else:
+            self.v6 = None
         if address_v4 and self.v4:
             self.v4.bind(address_v4)
         else:
             self.v4 = None
 
     def print_listening(self, what):
+        if self.v6:
+            listenip = self.v6.getsockname()
+            debug1('%s listening on %r.\n' % (what, listenip))
         if self.v4:
             listenip = self.v4.getsockname()
             debug1('%s listening on %r.\n' % (what, listenip))
 
 
 class FirewallClient:
-    def __init__(self, port_v4, subnets_include, subnets_exclude, dnsport_v4, method):
+    def __init__(self, port_v6, port_v4, subnets_include, subnets_exclude, dnsport_v6, dnsport_v4, method):
         self.auto_nets = []
         self.subnets_include = subnets_include
         self.subnets_exclude = subnets_exclude
         argvbase = ([sys.argv[1], sys.argv[0], sys.argv[1]] +
                     ['-v'] * (helpers.verbose or 0) +
-                    ['--firewall', str(port_v4),
-                                   str(dnsport_v4),
+                    ['--firewall', str(port_v6), str(port_v4),
+                                   str(dnsport_v6), str(dnsport_v4),
                                    method])
         if ssyslog._p:
             argvbase += ['--syslog']
@@ -376,7 +390,7 @@ def _main(tcp_listener, fw, ssh_cmd, remotename, python, latency_control,
         mux.callback()
 
 
-def main(listenip_v4,
+def main(listenip_v6, listenip_v4,
          ssh_cmd, remotename, python, latency_control, dns,
          method, seed_hosts, auto_nets,
          subnets_include, subnets_exclude, syslog, daemon, pidfile):
@@ -390,7 +404,7 @@ def main(listenip_v4,
             return 5
     debug1('Starting sshuttle proxy.\n')
 
-    if listenip_v4 and listenip_v4[1]:
+    if listenip_v6 and listenip_v6[1] and listenip_v4 and listenip_v4[1]:
         # if both ports given, no need to search for a spare port
         ports = [ 0, ]
     else:
@@ -399,6 +413,7 @@ def main(listenip_v4,
 
     # search for free ports and try to bind
     last_e = None
+    redirectport_v6 = 0
     redirectport_v4 = 0
     bound = False
     debug2('Binding redirector:')
@@ -407,6 +422,16 @@ def main(listenip_v4,
         tcp_listener = MultiListener()
         tcp_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 
+        if listenip_v6 and listenip_v6[1]:
+            lv6 = listenip_v6
+            redirectport_v6 = lv6[1]
+        elif listenip_v6:
+            lv6 = (listenip_v6[0],port)
+            redirectport_v6 = port
+        else:
+            lv6 = None
+            redirectport_v6 = 0
+
         if listenip_v4 and listenip_v4[1]:
             lv4 = listenip_v4
             redirectport_v4 = lv4[1]
@@ -418,7 +443,7 @@ def main(listenip_v4,
             redirectport_v4 = 0
 
         try:
-            tcp_listener.bind(lv4)
+            tcp_listener.bind(lv6, lv4)
             bound = True
             break
         except socket.error, e:
@@ -443,6 +468,13 @@ def main(listenip_v4,
             dns_listener = MultiListener(socket.SOCK_DGRAM)
             dns_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 
+            if listenip_v6:
+                lv6 = (listenip_v6[0],port)
+                dnsport_v6 = port
+            else:
+                lv6 = None
+                dnsport_v6 = 0
+
             if listenip_v4:
                 lv4 = (listenip_v4[0],port)
                 dnsport_v4 = port
@@ -451,7 +483,7 @@ def main(listenip_v4,
                 dnsport_v4 = 0
 
             try:
-                dns_listener.bind(lv4)
+                dns_listener.bind(lv6, lv4)
                 bound = True
                 break
             except socket.error, e:
@@ -465,10 +497,11 @@ def main(listenip_v4,
             assert(last_e)
             raise last_e
     else:
+        dnsport_v6 = 0
         dnsport_v4 = 0
         dns_listener = None
 
-    fw = FirewallClient(redirectport_v4, subnets_include, subnets_exclude, dnsport_v4, method)
+    fw = FirewallClient(redirectport_v6, redirectport_v4, subnets_include, subnets_exclude, dnsport_v6, dnsport_v4, method)
 
     if fw.method == "tproxy":
         tcp_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)

firewall.py

@@ -15,7 +15,9 @@ def nonfatal(func, *args):
 
 
 def ipt_chain_exists(family, table, name):
-    if family == socket.AF_INET:
+    if family == socket.AF_INET6:
+        cmd = 'ip6tables'
+    elif family == socket.AF_INET:
         cmd = 'iptables'
     else:
         raise Exception('Unsupported family "%s"'%family_to_string(family))
@@ -30,7 +32,9 @@ def ipt_chain_exists(family, table, name):
 
 
 def _ipt(family, table, *args):
-    if family == socket.AF_INET:
+    if family == socket.AF_INET6:
+        argv = ['ip6tables', '-t', table] + list(args)
+    elif family == socket.AF_INET:
         argv = ['iptables', '-t', table] + list(args)
     else:
         raise Exception('Unsupported family "%s"'%family_to_string(family))
@@ -110,7 +114,7 @@ def do_iptables_nat(port, dnsport, family, subnets):
                 
     if dnsport:
         nslist = resolvconf_nameservers()
-        for ip in nslist:
+        for f,ip in filter(lambda i: i[0]==family, nslist):
             ipt_ttl('-A', chain, '-j', 'REDIRECT',
                     '--dest', '%s/32' % ip,
                     '-p', 'udp',
@@ -119,7 +123,7 @@ def do_iptables_nat(port, dnsport, family, subnets):
 
 
 def do_iptables_tproxy(port, dnsport, family, subnets):
-    if family not in [socket.AF_INET]:
+    if family not in [socket.AF_INET, socket.AF_INET6]:
         raise Exception('Address family "%s" unsupported by tproxy method'%family_to_string(family))
 
     table = "mangle"
@@ -367,7 +371,7 @@ def do_ipfw(port, dnsport, family, subnets):
         divertsock.bind(('0.0.0.0', port)) # IP field is ignored
 
         nslist = resolvconf_nameservers()
-        for ip in nslist:
+        for f,ip in filter(lambda i: i[0]==family, nslist):
             # relabel and then catch outgoing DNS requests
             ipfw('add', sport, 'divert', sport,
                  'log', 'udp',
@@ -450,9 +454,13 @@ def restore_etc_hosts(port):
 # exit.  In case that fails, it's not the end of the world; future runs will
 # supercede it in the transproxy list, at least, so the leftover rules
 # are hopefully harmless.
-def main(port_v4, dnsport_v4, method, syslog):
-    assert(port_v4 > 0)
+def main(port_v6, port_v4, dnsport_v6, dnsport_v4, method, syslog):
+    assert(port_v6 >= 0)
+    assert(port_v6 <= 65535)
+    assert(port_v4 >= 0)
     assert(port_v4 <= 65535)
+    assert(dnsport_v6 >= 0)
+    assert(dnsport_v6 <= 65535)
     assert(dnsport_v4 >= 0)
     assert(dnsport_v4 <= 65535)
 
@@ -519,6 +527,12 @@ def main(port_v4, dnsport_v4, method, syslog):
         if line:
             debug1('firewall manager: starting transproxy.\n')
 
+            subnets_v6 = filter(lambda i: i[0]==socket.AF_INET6, subnets)
+            if port_v6:
+                do_wait = do_it(port_v6, dnsport_v6, socket.AF_INET6, subnets_v6)
+            elif len(subnets_v6) > 0:
+                debug1("IPv6 subnets defined but IPv6 disabled\n")
+
             subnets_v4 = filter(lambda i: i[0]==socket.AF_INET, subnets)
             if port_v4:
                 do_wait = do_it(port_v4, dnsport_v4, socket.AF_INET, subnets_v4)
@@ -543,7 +557,7 @@ def main(port_v4, dnsport_v4, method, syslog):
             if line.startswith('HOST '):
                 (name,ip) = line[5:].strip().split(',', 1)
                 hostmap[name] = ip
-                rewrite_etc_hosts(port_v4)
+                rewrite_etc_hosts(port_v6 or port_v4)
             elif line:
                 raise Fatal('expected EOF, got %r' % line)
             else:
@@ -555,4 +569,4 @@ def main(port_v4, dnsport_v4, method, syslog):
             pass
         if port_v4:
             do_it(port_v4, 0, socket.AF_INET, [])
-        restore_etc_hosts(port_v4)
+        restore_etc_hosts(port_v6 or port_v4)

helpers.py

@@ -42,7 +42,10 @@ def resolvconf_nameservers():
     for line in open('/etc/resolv.conf'):
         words = line.lower().split()
         if len(words) >= 2 and words[0] == 'nameserver':
-            l.append(words[1])
+            if ':' in words[1]:
+                l.append((socket.AF_INET6,words[1]))
+            else:
+                l.append((socket.AF_INET,words[1]))
     return l
 
 
@@ -55,7 +58,7 @@ def resolvconf_random_nameserver():
             random.shuffle(l)
         return l[0]
     else:
-        return '127.0.0.1'
+        return (socket.AF_INET,'127.0.0.1')
     
 
 def islocal(ip,family):

main.py

@@ -22,12 +22,31 @@ def parse_subnet4(s):
     return(socket.AF_INET, '%d.%d.%d.%d' % (a,b,c,d), width)
 
 
+# 1:2::3/64 or just 1:2::3
+def parse_subnet6(s):
+    m = re.match(r'(?:([a-fA-F\d:]+))?(?:/(\d+))?$', s)
+    if not m:
+        raise Fatal('%r is not a valid IP subnet format' % s)
+    (net,width) = m.groups()
+    if width == None:
+        width = 128
+    else:
+        width = int(width)
+    if width > 128:
+        raise Fatal('*/%d is greater than the maximum of 128' % width)
+    return(socket.AF_INET6, net, width)
+
+
 # list of:
 # 1.2.3.4/5 or just 1.2.3.4
+# 1:2::3/64 or just 1:2::3
 def parse_subnets(subnets_str):
     subnets = []
     for s in subnets_str:
-        subnet = parse_subnet4(s)
+        if ':' in s:
+            subnet = parse_subnet6(s)
+        else:
+            subnet = parse_subnet4(s)
         subnets.append(subnet)
     return subnets
 
@@ -50,13 +69,24 @@ def parse_ipport4(s):
     return ('%d.%d.%d.%d' % (a,b,c,d), port)
 
 
+# [1:2::3]:456 or [1:2::3] or 456
+def parse_ipport6(s):
+    s = str(s)
+    m = re.match(r'(?:\[([^]]*)])?(?::)?(?:(\d+))?$', s)
+    if not m:
+        raise Fatal('%s is not a valid IP:port format' % s)
+    (ip,port) = m.groups()
+    (ip,port) = (ip or '::', int(port or 0))
+    return (ip, port)
+
+
 optspec = """
 sshuttle [-l [ip:]port] [-r [username@]sshserver[:port]] <subnets...>
 sshuttle --server
 sshuttle --firewall <port> <subnets...>
 sshuttle --hostwatch
 --
-l,listen=  transproxy to this ip address and port number [127.0.0.1:0]
+l,listen=  transproxy to this ip address and port number
 H,auto-hosts scan for remote hostnames and update local /etc/hosts
 N,auto-nets  automatically determine subnets to route
 dns        capture local DNS requests and forward to the remote DNS server
@@ -93,10 +123,11 @@ try:
         server.latency_control = opt.latency_control
         sys.exit(server.main())
     elif opt.firewall:
-        if len(extra) != 3:
-            o.fatal('exactly three arguments expected')
+        if len(extra) != 5:
+            o.fatal('exactly five arguments expected')
         sys.exit(firewall.main(int(extra[0]), int(extra[1]),
-                                extra[2], opt.syslog))
+                               int(extra[2]), int(extra[3]),
+                                extra[4], opt.syslog))
     elif opt.hostwatch:
         sys.exit(hostwatch.hw_main(extra))
     else:
@@ -124,8 +155,22 @@ try:
             method = opt.method
         else:
             o.fatal("method %s not supported"%opt.method)
-        ipport_v4 = parse_ipport4(opt.listen or '0.0.0.0:0')
-        sys.exit(client.main(ipport_v4,
+        if not opt.listen:
+            if opt.method == "tproxy":
+                ipport_v6 = parse_ipport6('[::1]:0')
+            else:
+                ipport_v6 = None
+            ipport_v4 = parse_ipport4('127.0.0.1:0')
+        else:
+            ipport_v6 = None
+            ipport_v4 = None
+            list = opt.listen.split(",")
+            for ip in list:
+                if '[' in ip and ']' in ip and opt.method == "tproxy":
+                    ipport_v6 = parse_ipport6(ip)
+                else:
+                    ipport_v4 = parse_ipport4(ip)
+        sys.exit(client.main(ipport_v6, ipport_v4,
                              opt.ssh_cmd,
                              remotename,
                              opt.python,

server.py

@@ -108,6 +108,7 @@ class Hostwatch:
 
 class DnsProxy(Handler):
     def __init__(self, mux, chan, request):
+        # FIXME! IPv4 specific
         sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
         Handler.__init__(self, [sock])
         self.timeout = time.time()+30
@@ -117,6 +118,7 @@ class DnsProxy(Handler):
         self.peer = None
         self.request = request
         self.sock = sock
+        # FIXME! IPv4 specific
         self.sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
         self.try_send()
 
@@ -124,7 +126,8 @@ class DnsProxy(Handler):
         if self.tries >= 3:
             return
         self.tries += 1
-        self.peer = resolvconf_random_nameserver()
+        # FIXME! Support IPv6 nameservers
+        self.peer = resolvconf_random_nameserver()[1]
         self.sock.connect((self.peer, 53))
         debug2('DNS: sending to %r\n' % self.peer)
         try: