lib/dnspython/dns/rdtypes/IN/WKS.py

   1 # Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
   2 #
   3 # Permission to use, copy, modify, and distribute this software and its
   4 # documentation for any purpose with or without fee is hereby granted,
   5 # provided that the above copyright notice and this permission notice
   6 # appear in all copies.
   7 #
   8 # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
   9 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  11 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  14 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15
  16 import socket
  17 import struct
  18
  19 import dns.ipv4
  20 import dns.rdata
  21
  22 _proto_tcp = socket.getprotobyname('tcp')
  23 _proto_udp = socket.getprotobyname('udp')
  24
  25 class WKS(dns.rdata.Rdata):
  26     """WKS record
  27
  28     @ivar address: the address
  29     @type address: string
  30     @ivar protocol: the protocol
  31     @type protocol: int
  32     @ivar bitmap: the bitmap
  33     @type bitmap: string
  34     @see: RFC 1035"""
  35
  36     __slots__ = ['address', 'protocol', 'bitmap']
  37
  38     def __init__(self, rdclass, rdtype, address, protocol, bitmap):
  39         super(WKS, self).__init__(rdclass, rdtype)
  40         self.address = address
  41         self.protocol = protocol
  42         self.bitmap = bitmap
  43
  44     def to_text(self, origin=None, relativize=True, **kw):
  45         bits = []
  46         for i in xrange(0, len(self.bitmap)):
  47             byte = ord(self.bitmap[i])
  48             for j in xrange(0, 8):
  49                 if byte & (0x80 >> j):
  50                     bits.append(str(i * 8 + j))
  51         text = ' '.join(bits)
  52         return '%s %d %s' % (self.address, self.protocol, text)
  53
  54     def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
  55         address = tok.get_string()
  56         protocol = tok.get_string()
  57         if protocol.isdigit():
  58             protocol = int(protocol)
  59         else:
  60             protocol = socket.getprotobyname(protocol)
  61         bitmap = []
  62         while 1:
  63             token = tok.get().unescape()
  64             if token.is_eol_or_eof():
  65                 break
  66             if token.value.isdigit():
  67                 serv = int(token.value)
  68             else:
  69                 if protocol != _proto_udp and protocol != _proto_tcp:
  70                     raise NotImplementedError("protocol must be TCP or UDP")
  71                 if protocol == _proto_udp:
  72                     protocol_text = "udp"
  73                 else:
  74                     protocol_text = "tcp"
  75                 serv = socket.getservbyname(token.value, protocol_text)
  76             i = serv // 8
  77             l = len(bitmap)
  78             if l < i + 1:
  79                 for j in xrange(l, i + 1):
  80                     bitmap.append('\x00')
  81             bitmap[i] = chr(ord(bitmap[i]) | (0x80 >> (serv % 8)))
  82         bitmap = dns.rdata._truncate_bitmap(bitmap)
  83         return cls(rdclass, rdtype, address, protocol, bitmap)
  84
  85     from_text = classmethod(from_text)
  86
  87     def to_wire(self, file, compress = None, origin = None):
  88         file.write(dns.ipv4.inet_aton(self.address))
  89         protocol = struct.pack('!B', self.protocol)
  90         file.write(protocol)
  91         file.write(self.bitmap)
  92
  93     def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
  94         address = dns.ipv4.inet_ntoa(wire[current : current + 4])
  95         protocol, = struct.unpack('!B', wire[current + 4 : current + 5])
  96         current += 5
  97         rdlen -= 5
  98         bitmap = wire[current : current + rdlen].unwrap()
  99         return cls(rdclass, rdtype, address, protocol, bitmap)
 100
 101     from_wire = classmethod(from_wire)
 102
 103     def _cmp(self, other):
 104         sa = dns.ipv4.inet_aton(self.address)
 105         oa = dns.ipv4.inet_aton(other.address)
 106         v = cmp(sa, oa)
 107         if v == 0:
 108             sp = struct.pack('!B', self.protocol)
 109             op = struct.pack('!B', other.protocol)
 110             v = cmp(sp, op)
 111             if v == 0:
 112                 v = cmp(self.bitmap, other.bitmap)
 113         return v