# Twisted, the Framework of Your Internet
# Copyright (C) 2001 Matthew W. Lefkowitz
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""
Implementation of the SOCKSv4 protocol.
"""
# twisted imports
from twisted.internet import reactor,protocol,defer
from twisted.python import log
# python imports
import struct
import string
import socket
import time
class SOCKSv4Outgoing(protocol.Protocol):
def __init__(self,socks):
self.socks=socks
def connectionMade(self):
junk, host, port = self.transport.getPeer()
self.socks.makeReply(90, 0, port=port, ip=host)
self.socks.otherConn=self
def connectionLost(self, reason):
self.socks.transport.loseConnection()
def dataReceived(self,data):
self.socks.write(data)
def write(self,data):
self.socks.log(self,data)
self.transport.write(data)
class SOCKSv4Incoming(protocol.Protocol):
def __init__(self,socks):
self.socks=socks
self.socks.otherConn=self
def connectionLost(self, reason):
self.socks.transport.loseConnection()
def dataReceived(self,data):
self.socks.write(data)
def write(self,data):
self.socks.log(self,data)
self.transport.write(data)
class SOCKSv4(protocol.Protocol):
def __init__(self,logging=None):
self.logging=logging
def connectionMade(self):
self.buf=""
self.otherConn=None
def dataReceived(self,data):
if self.otherConn:
self.otherConn.write(data)
return
self.buf=self.buf+data
if '\000' in self.buf[8:]:
head,self.buf=self.buf[:8],self.buf[8:]
try:
version,code,port=struct.unpack("!BBH",head[:4])
except struct.error:
raise RuntimeError, "struct error with head='%s' and buf='%s'"%(repr(head),repr(self.buf))
user,self.buf=string.split(self.buf,"\000",1)
if head[4:7]=="\000\000\000": # domain is after
server,self.buf=string.split(self.buf,'\000',1)
#server=gethostbyname(server)
else:
server=socket.inet_ntoa(head[4:8])
assert version==4, "Bad version code: %s"%version
if not self.authorize(code,server,port,user):
self.makeReply(91)
return
if code==1: # CONNECT
d = self.connectClass(server, port, SOCKSv4Outgoing, self)
d.addErrback(lambda result, self=self: self.makeReply(91))
elif code==2: # BIND
ip = socket.gethostbyname(server)
d = self.listenClass(0, SOCKSv4IncomingFactory, self, ip)
d.addCallback(lambda (h, p), self=self: self.makeReply(90, 0, p, h))
else:
raise RuntimeError, "Bad Connect Code: %s" % code
assert self.buf=="","hmm, still stuff in buffer... %s" % repr(self.buf)
def authorize(self,code,server,port,user):
log.msg("code %s connection to %s:%s (user %s) authorized" % (code,server,port,user))
return 1
def connectClass(self, host, port, klass, *args):
return protocol.ClientCreator(reactor, klass, *args).connectTCP(host,port)
def listenClass(self, port, klass, *args):
serv = reactor.listenTCP(port, klass(*args))
return defer.succeed(serv.getHost()[1:])
def makeReply(self,reply,version=0,port=0,ip="0.0.0.0"):
self.transport.write(struct.pack("!BBH",version,reply,port)+socket.inet_aton(ip))
if reply!=90: self.transport.loseConnection()
def write(self,data):
self.log(self,data)
self.transport.write(data)
def log(self,proto,data):
if not self.logging: return
foo,ourhost,ourport=self.transport.getPeer()
foo,theirhost,theirport=self.otherConn.transport.getPeer()
f=open(self.logging,"a")
f.write("%s\t%s:%d %s %s:%d\n"%(time.ctime(),
ourhost,ourport,
((proto==self and '<') or '>'),
theirhost,theirport))
while data:
p,data=data[:16],data[16:]
f.write(string.join(map(lambda x:'%02X'%ord(x),p),' ')+' ')
f.write((16-len(p))*3*' ')
for c in p:
if len(repr(c))>3: f.write('.')
else: f.write(c)
f.write('\n')
f.write('\n')
f.close()
class SOCKSv4Factory(protocol.Factory):
"""A factory for a SOCKSv4 proxy.
Constructor accepts one argument, a logfile.
"""
def __init__(self, log):
self.logging = log
def buildProtocol(self, addr):
return SOCKSv4(self.logging)
class SOCKSv4IncomingFactory(protocol.Factory):
"""A utility class for building protocols for incoming connections."""
def __init__(self, socks, ip):
self.socks = socks
self.ip = ip
def buildProtocol(self, addr):
if addr[0] == self.ip:
self.ip = ""
self.socks.makeReply(90, 0)
return SOCKSv4Incoming(self.socks)
elif self.ip == "":
return None
else:
self.socks.makeReply(91, 0)
self.ip = ""
return None
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