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 struct
17
18import dns.exception
19import dns.rdata
20import dns.name
21
22class SOA(dns.rdata.Rdata):
23    """SOA record
24
25    @ivar mname: the SOA MNAME (master name) field
26    @type mname: dns.name.Name object
27    @ivar rname: the SOA RNAME (responsible name) field
28    @type rname: dns.name.Name object
29    @ivar serial: The zone's serial number
30    @type serial: int
31    @ivar refresh: The zone's refresh value (in seconds)
32    @type refresh: int
33    @ivar retry: The zone's retry value (in seconds)
34    @type retry: int
35    @ivar expire: The zone's expiration value (in seconds)
36    @type expire: int
37    @ivar minimum: The zone's negative caching time (in seconds, called
38    "minimum" for historical reasons)
39    @type minimum: int
40    @see: RFC 1035"""
41
42    __slots__ = ['mname', 'rname', 'serial', 'refresh', 'retry', 'expire',
43                 'minimum']
44
45    def __init__(self, rdclass, rdtype, mname, rname, serial, refresh, retry,
46                 expire, minimum):
47        super(SOA, self).__init__(rdclass, rdtype)
48        self.mname = mname
49        self.rname = rname
50        self.serial = serial
51        self.refresh = refresh
52        self.retry = retry
53        self.expire = expire
54        self.minimum = minimum
55
56    def to_text(self, origin=None, relativize=True, **kw):
57        mname = self.mname.choose_relativity(origin, relativize)
58        rname = self.rname.choose_relativity(origin, relativize)
59        return '%s %s %d %d %d %d %d' % (
60            mname, rname, self.serial, self.refresh, self.retry,
61            self.expire, self.minimum )
62
63    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
64        mname = tok.get_name()
65        rname = tok.get_name()
66        mname = mname.choose_relativity(origin, relativize)
67        rname = rname.choose_relativity(origin, relativize)
68        serial = tok.get_uint32()
69        refresh = tok.get_ttl()
70        retry = tok.get_ttl()
71        expire = tok.get_ttl()
72        minimum = tok.get_ttl()
73        tok.get_eol()
74        return cls(rdclass, rdtype, mname, rname, serial, refresh, retry,
75                   expire, minimum )
76
77    from_text = classmethod(from_text)
78
79    def to_wire(self, file, compress = None, origin = None):
80        self.mname.to_wire(file, compress, origin)
81        self.rname.to_wire(file, compress, origin)
82        five_ints = struct.pack('!IIIII', self.serial, self.refresh,
83                                self.retry, self.expire, self.minimum)
84        file.write(five_ints)
85
86    def to_digestable(self, origin = None):
87        return self.mname.to_digestable(origin) + \
88            self.rname.to_digestable(origin) + \
89            struct.pack('!IIIII', self.serial, self.refresh,
90                        self.retry, self.expire, self.minimum)
91
92    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
93        (mname, cused) = dns.name.from_wire(wire[: current + rdlen], current)
94        current += cused
95        rdlen -= cused
96        (rname, cused) = dns.name.from_wire(wire[: current + rdlen], current)
97        current += cused
98        rdlen -= cused
99        if rdlen != 20:
100            raise dns.exception.FormError
101        five_ints = struct.unpack('!IIIII',
102                                  wire[current : current + rdlen])
103        if not origin is None:
104            mname = mname.relativize(origin)
105            rname = rname.relativize(origin)
106        return cls(rdclass, rdtype, mname, rname,
107                   five_ints[0], five_ints[1], five_ints[2], five_ints[3],
108                   five_ints[4])
109
110    from_wire = classmethod(from_wire)
111
112    def choose_relativity(self, origin = None, relativize = True):
113        self.mname = self.mname.choose_relativity(origin, relativize)
114        self.rname = self.rname.choose_relativity(origin, relativize)
115
116    def _cmp(self, other):
117        v = cmp(self.mname, other.mname)
118        if v == 0:
119            v = cmp(self.rname, other.rname)
120            if v == 0:
121                self_ints = struct.pack('!IIIII', self.serial, self.refresh,
122                                        self.retry, self.expire, self.minimum)
123                other_ints = struct.pack('!IIIII', other.serial, other.refresh,
124                                         other.retry, other.expire,
125                                         other.minimum)
126                v = cmp(self_ints, other_ints)
127        return v
128