client now listens on a socket and gets SO_ORIGINAL_DST correctly.

client.py

+import struct
+from socket import *
+from helpers import *
+
+
+def original_dst(sock):
+    SO_ORIGINAL_DST = 80
+    SOCKADDR_MIN = 16
+    sockaddr_in = sock.getsockopt(SOL_IP, SO_ORIGINAL_DST, SOCKADDR_MIN)
+    (proto, port, a,b,c,d) = struct.unpack('!hhBBBB', sockaddr_in[:8])
+    assert(htons(proto) == AF_INET)
+    ip = '%d.%d.%d.%d' % (a,b,c,d)
+    return (ip,port)
+
+
+def main(remotename, subnets):
+    log('Starting sshuttle proxy.\n')
+    listener = socket()
+    listener.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
+    listener.bind(('0.0.0.0',1234))
+    listener.listen(10)
+    log('Listening on %r.\n' % (listener.getsockname(),))
+    while 1:
+        s,srcip = listener.accept()
+        dstip = original_dst(s)
+        print 'Incoming connection from %r to %r.' % (srcip,dstip)
+        

helpers.py

+import sys, os
+
+def log(s):
+    sys.stdout.flush()
+    sys.stderr.write(s)
+    sys.stderr.flush()