contrib/tor-resolve.py

   1 #!/usr/bin/python
   2 #$Id$
   3
   4 import socket
   5 import struct
   6 import sys
   7
   8 def socks4AResolveRequest(hostname):
   9     version = 4
  10     command = 0xF0
  11     port = 0
  12     addr = 0x0000001
  13     username = ""
  14     reqheader = struct.pack("!BBHL", version, command, port, addr)
  15     return "%s%s\x00%s\x00"%(reqheader,username,hostname)
  16
  17 def socks4AParseResponse(response):
  18     RESPONSE_LEN = 8
  19     if len(response) < RESPONSE_LEN:
  20         return None
  21     assert len(response) >= RESPONSE_LEN
  22     version,status,port = struct.unpack("!BBH",response[:4])
  23     assert version == 0
  24     assert port == 0
  25     if status == 90:
  26         return "%d.%d.%d.%d"%tuple(map(ord, response[4:]))
  27     else:
  28         return "ERROR (status %d)"%status
  29
  30 def socks5Hello():
  31     return "\x05\x01\x00"
  32 def socks5ParseHello(response):
  33     if response != "\x05\x00":
  34         raise ValueError("Bizarre socks5 response")
  35 def socks5ResolveRequest(hostname, atype=0x03, command=0xF0):
  36     version = 5
  37     rsv = 0
  38     port = 0
  39     reqheader = struct.pack("!BBBB",version, command, rsv, atype)
  40     if atype == 0x03:
  41         reqheader += struct.pack("!B", len(hostname))
  42     portstr = struct.pack("!H",port)
  43     return "%s%s%s"%(reqheader,hostname,portstr)
  44
  45 def socks5ParseResponse(r):
  46     if len(r)<8:
  47         return None
  48     version, reply, rsv, atype = struct.unpack("!BBBB",r[:4])
  49     assert version==5
  50     assert rsv==0
  51     if reply != 0x00:
  52         return "ERROR",reply
  53     assert atype in (0x01,0x03,0x04)
  54     if atype != 0x03:
  55         expected_len = 4 + ({1:4,4:16}[atype]) + 2
  56         if len(r) < expected_len:
  57             return None
  58         elif len(r) > expected_len:
  59             raise ValueError("Overlong socks5 reply!")
  60         addr = r[4:-2]
  61         if atype == 0x01:
  62             return "%d.%d.%d.%d"%tuple(map(ord,addr))
  63         else:
  64             # not really the right way to format IPv6
  65             return "IPv6: %s"%(":".join([hex(ord(c)) for c in addr]))
  66     else:
  67         hlen, = struct.unpack("!B", r[4])
  68         expected_len = 5 + hlen + 2
  69         if len(r) < expected_len:
  70             return None
  71         return r[5:-2]
  72
  73 def socks5ResolvePTRRequest(hostname):
  74     return socks5ResolveRequest(socket.inet_aton(hostname),
  75                                 atype=1, command = 0xF1)
  76
  77
  78 def parseHostAndPort(h):
  79     host, port = "localhost", 9050
  80     if ":" in h:
  81         i = h.index(":")
  82         host = h[:i]
  83         try:
  84             port = int(h[i+1:])
  85         except ValueError:
  86             print "Bad hostname %r"%h
  87             sys.exit(1)
  88     elif h:
  89         try:
  90             port = int(h)
  91         except ValueError:
  92             host = h
  93
  94     return host, port
  95
  96 def resolve(hostname, sockshost, socksport, socksver=4, reverse=0):
  97     assert socksver in (4,5)
  98     if socksver == 4:
  99         fmt = socks4AResolveRequest
 100         parse = socks4AParseResponse
 101     elif not reverse:
 102         fmt = socks5ResolveRequest
 103         parse = socks5ParseResponse
 104     else:
 105         fmt = socks5ResolvePTRRequest
 106         parse = socks5ParseResponse
 107
 108     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 109     s.connect((sockshost,socksport))
 110     if socksver == 5:
 111         s.send(socks5Hello())
 112         socks5ParseHello(s.recv(2))
 113     s.send(fmt(hostname))
 114     answer = s.recv(6)
 115     result = parse(answer)
 116     while result is None:
 117         more = s.recv(1)
 118         if not more:
 119             return None
 120         answer += more
 121         result = parse(answer)
 122     print "Got answer",result
 123     m = s.recv(1)
 124     if m:
 125         print "Got extra data too: %r"%m
 126     return result
 127
 128 if __name__ == '__main__':
 129     if len(sys.argv) not in (2,3,4):
 130         print "Syntax: resolve.py [-4|-5] hostname [sockshost:socksport]"
 131         sys.exit(0)
 132     socksver = 4
 133     reverse = 0
 134     while sys.argv[1][0] == '-':
 135         if sys.argv[1] in ("-4", "-5"):
 136             socksver = int(sys.argv[1][1])
 137             del sys.argv[1]
 138         elif sys.argv[1] == '-x':
 139             reverse = 1
 140             del sys.argv[1]
 141         elif sys.argv[1] == '--':
 142             break
 143
 144     if len(sys.argv) >= 4:
 145         print "Syntax: resolve.py [-x] [-4|-5] hostname [sockshost:socksport]"
 146         sys.exit(0)
 147     if len(sys.argv) == 3:
 148         sh,sp = parseHostAndPort(sys.argv[2])
 149     else:
 150         sh,sp = parseHostAndPort("")
 151
 152     if reverse and socksver == 4:
 153         socksver = 5
 154     resolve(sys.argv[1], sh, sp, socksver, reverse)