1# Copyright (C) 2003-2007, 2009, 2010 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
16import dns.exception
17import dns.rdata
18import dns.rdatatype
19import dns.name
20
21class NXT(dns.rdata.Rdata):
22    """NXT record
23
24    @ivar next: the next name
25    @type next: dns.name.Name object
26    @ivar bitmap: the type bitmap
27    @type bitmap: string
28    @see: RFC 2535"""
29
30    __slots__ = ['next', 'bitmap']
31
32    def __init__(self, rdclass, rdtype, next, bitmap):
33        super(NXT, self).__init__(rdclass, rdtype)
34        self.next = next
35        self.bitmap = bitmap
36
37    def to_text(self, origin=None, relativize=True, **kw):
38        next = self.next.choose_relativity(origin, relativize)
39        bits = []
40        for i in xrange(0, len(self.bitmap)):
41            byte = ord(self.bitmap[i])
42            for j in xrange(0, 8):
43                if byte & (0x80 >> j):
44                    bits.append(dns.rdatatype.to_text(i * 8 + j))
45        text = ' '.join(bits)
46        return '%s %s' % (next, text)
47
48    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
49        next = tok.get_name()
50        next = next.choose_relativity(origin, relativize)
51        bitmap = ['\x00', '\x00', '\x00', '\x00',
52                  '\x00', '\x00', '\x00', '\x00',
53                  '\x00', '\x00', '\x00', '\x00',
54                  '\x00', '\x00', '\x00', '\x00' ]
55        while 1:
56            token = tok.get().unescape()
57            if token.is_eol_or_eof():
58                break
59            if token.value.isdigit():
60                nrdtype = int(token.value)
61            else:
62                nrdtype = dns.rdatatype.from_text(token.value)
63            if nrdtype == 0:
64                raise dns.exception.SyntaxError("NXT with bit 0")
65            if nrdtype > 127:
66                raise dns.exception.SyntaxError("NXT with bit > 127")
67            i = nrdtype // 8
68            bitmap[i] = chr(ord(bitmap[i]) | (0x80 >> (nrdtype % 8)))
69        bitmap = dns.rdata._truncate_bitmap(bitmap)
70        return cls(rdclass, rdtype, next, bitmap)
71
72    from_text = classmethod(from_text)
73
74    def to_wire(self, file, compress = None, origin = None):
75        self.next.to_wire(file, None, origin)
76        file.write(self.bitmap)
77
78    def to_digestable(self, origin = None):
79        return self.next.to_digestable(origin) + self.bitmap
80
81    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
82        (next, cused) = dns.name.from_wire(wire[: current + rdlen], current)
83        current += cused
84        rdlen -= cused
85        bitmap = wire[current : current + rdlen]
86        if not origin is None:
87            next = next.relativize(origin)
88        return cls(rdclass, rdtype, next, bitmap)
89
90    from_wire = classmethod(from_wire)
91
92    def choose_relativity(self, origin = None, relativize = True):
93        self.next = self.next.choose_relativity(origin, relativize)
94
95    def _cmp(self, other):
96        v = cmp(self.next, other.next)
97        if v == 0:
98            v = cmp(self.bitmap, other.bitmap)
99        return v
100