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# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
import struct
import dns.exception
import dns.rdata
import dns.name
class SRV(dns.rdata.Rdata):
"""SRV record
@ivar priority: the priority
@type priority: int
@ivar weight: the weight
@type weight: int
@ivar port: the port of the service
@type port: int
@ivar target: the target host
@type target: dns.name.Name object
@see: RFC 2782"""
__slots__ = ['priority', 'weight', 'port', 'target']
def __init__(self, rdclass, rdtype, priority, weight, port, target):
super(SRV, self).__init__(rdclass, rdtype)
self.priority = priority
self.weight = weight
self.port = port
self.target = target
def to_text(self, origin=None, relativize=True, **kw):
target = self.target.choose_relativity(origin, relativize)
return '%d %d %d %s' % (self.priority, self.weight, self.port,
target)
def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
priority = tok.get_uint16()
weight = tok.get_uint16()
port = tok.get_uint16()
target = tok.get_name(None)
target = target.choose_relativity(origin, relativize)
tok.get_eol()
return cls(rdclass, rdtype, priority, weight, port, target)
from_text = classmethod(from_text)
def to_wire(self, file, compress = None, origin = None):
three_ints = struct.pack("!HHH", self.priority, self.weight, self.port)
file.write(three_ints)
self.target.to_wire(file, compress, origin)
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
(priority, weight, port) = struct.unpack('!HHH',
wire[current : current + 6])
current += 6
rdlen -= 6
(target, cused) = dns.name.from_wire(wire[: current + rdlen],
current)
if cused != rdlen:
raise dns.exception.FormError
if not origin is None:
target = target.relativize(origin)
return cls(rdclass, rdtype, priority, weight, port, target)
from_wire = classmethod(from_wire)
def choose_relativity(self, origin = None, relativize = True):
self.target = self.target.choose_relativity(origin, relativize)
def _cmp(self, other):
sp = struct.pack("!HHH", self.priority, self.weight, self.port)
op = struct.pack("!HHH", other.priority, other.weight, other.port)
v = cmp(sp, op)
if v == 0:
v = cmp(self.target, other.target)
return v
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