client.py: do DNS listener on the same port as the TCP listener.

UDP and TCP have separate port namespaces, so to make it easier to keep
track of what's going on, just use the same transproxy port number for both.
We still need two sockets, but now tcpdumps are easier to understand.

client.py

@@ -330,8 +330,6 @@ def main(listenip, ssh_cmd, remotename, python, latency_control, dns,
             return 5
     debug1('Starting sshuttle proxy.\n')
     
-    listener = socket.socket()
-    listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
     if listenip[1]:
         ports = [listenip[1]]
     else:
@@ -341,8 +339,13 @@ def main(listenip, ssh_cmd, remotename, python, latency_control, dns,
     debug2('Binding:')
     for port in ports:
         debug2(' %d' % port)
+        listener = socket.socket()
+        listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        dnslistener = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        dnslistener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         try:
             listener.bind((listenip[0], port))
+            dnslistener.bind((listenip[0], port))
             bound = True
             break
         except socket.error, e:
@@ -355,14 +358,14 @@ def main(listenip, ssh_cmd, remotename, python, latency_control, dns,
     listenip = listener.getsockname()
     debug1('Listening on %r.\n' % (listenip,))
 
-    dnsport = 0
-    dnslistener = None
     if dns:
-        dnslistener = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-        dnslistener.bind((listenip[0], 0))
         dnsip = dnslistener.getsockname()
         debug1('DNS listening on %r.\n' % (dnsip,))
         dnsport = dnsip[1]
+    else:
+        dnsport = 0
+        dnslistener = None
+        dnslistener.bind((listenip[0], 0))
 
     fw = FirewallClient(listenip[1], subnets_include, subnets_exclude, dnsport)