+++ /dev/null
-# 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.
-
-"""Talk to a DNS server."""
-
-from __future__ import generators
-
-import errno
-import select
-import socket
-import struct
-import sys
-import time
-
-import dns.exception
-import dns.inet
-import dns.name
-import dns.message
-import dns.rdataclass
-import dns.rdatatype
-
-class UnexpectedSource(dns.exception.DNSException):
- """Raised if a query response comes from an unexpected address or port."""
- pass
-
-class BadResponse(dns.exception.FormError):
- """Raised if a query response does not respond to the question asked."""
- pass
-
-def _compute_expiration(timeout):
- if timeout is None:
- return None
- else:
- return time.time() + timeout
-
-def _poll_for(fd, readable, writable, error, timeout):
- """
- @param fd: File descriptor (int).
- @param readable: Whether to wait for readability (bool).
- @param writable: Whether to wait for writability (bool).
- @param expiration: Deadline timeout (expiration time, in seconds (float)).
-
- @return True on success, False on timeout
- """
- event_mask = 0
- if readable:
- event_mask |= select.POLLIN
- if writable:
- event_mask |= select.POLLOUT
- if error:
- event_mask |= select.POLLERR
-
- pollable = select.poll()
- pollable.register(fd, event_mask)
-
- if timeout:
- event_list = pollable.poll(long(timeout * 1000))
- else:
- event_list = pollable.poll()
-
- return bool(event_list)
-
-def _select_for(fd, readable, writable, error, timeout):
- """
- @param fd: File descriptor (int).
- @param readable: Whether to wait for readability (bool).
- @param writable: Whether to wait for writability (bool).
- @param expiration: Deadline timeout (expiration time, in seconds (float)).
-
- @return True on success, False on timeout
- """
- rset, wset, xset = [], [], []
-
- if readable:
- rset = [fd]
- if writable:
- wset = [fd]
- if error:
- xset = [fd]
-
- if timeout is None:
- (rcount, wcount, xcount) = select.select(rset, wset, xset)
- else:
- (rcount, wcount, xcount) = select.select(rset, wset, xset, timeout)
-
- return bool((rcount or wcount or xcount))
-
-def _wait_for(fd, readable, writable, error, expiration):
- done = False
- while not done:
- if expiration is None:
- timeout = None
- else:
- timeout = expiration - time.time()
- if timeout <= 0.0:
- raise dns.exception.Timeout
- try:
- if not _polling_backend(fd, readable, writable, error, timeout):
- raise dns.exception.Timeout
- except select.error, e:
- if e.args[0] != errno.EINTR:
- raise e
- done = True
-
-def _set_polling_backend(fn):
- """
- Internal API. Do not use.
- """
- global _polling_backend
-
- _polling_backend = fn
-
-if hasattr(select, 'poll'):
- # Prefer poll() on platforms that support it because it has no
- # limits on the maximum value of a file descriptor (plus it will
- # be more efficient for high values).
- _polling_backend = _poll_for
-else:
- _polling_backend = _select_for
-
-def _wait_for_readable(s, expiration):
- _wait_for(s, True, False, True, expiration)
-
-def _wait_for_writable(s, expiration):
- _wait_for(s, False, True, True, expiration)
-
-def _addresses_equal(af, a1, a2):
- # Convert the first value of the tuple, which is a textual format
- # address into binary form, so that we are not confused by different
- # textual representations of the same address
- n1 = dns.inet.inet_pton(af, a1[0])
- n2 = dns.inet.inet_pton(af, a2[0])
- return n1 == n2 and a1[1:] == a2[1:]
-
-def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0,
- ignore_unexpected=False, one_rr_per_rrset=False):
- """Return the response obtained after sending a query via UDP.
-
- @param q: the query
- @type q: dns.message.Message
- @param where: where to send the message
- @type where: string containing an IPv4 or IPv6 address
- @param timeout: The number of seconds to wait before the query times out.
- If None, the default, wait forever.
- @type timeout: float
- @param port: The port to which to send the message. The default is 53.
- @type port: int
- @param af: the address family to use. The default is None, which
- causes the address family to use to be inferred from the form of of where.
- If the inference attempt fails, AF_INET is used.
- @type af: int
- @rtype: dns.message.Message object
- @param source: source address. The default is the IPv4 wildcard address.
- @type source: string
- @param source_port: The port from which to send the message.
- The default is 0.
- @type source_port: int
- @param ignore_unexpected: If True, ignore responses from unexpected
- sources. The default is False.
- @type ignore_unexpected: bool
- @param one_rr_per_rrset: Put each RR into its own RRset
- @type one_rr_per_rrset: bool
- """
-
- wire = q.to_wire()
- if af is None:
- try:
- af = dns.inet.af_for_address(where)
- except:
- af = dns.inet.AF_INET
- if af == dns.inet.AF_INET:
- destination = (where, port)
- if source is not None:
- source = (source, source_port)
- elif af == dns.inet.AF_INET6:
- destination = (where, port, 0, 0)
- if source is not None:
- source = (source, source_port, 0, 0)
- s = socket.socket(af, socket.SOCK_DGRAM, 0)
- try:
- expiration = _compute_expiration(timeout)
- s.setblocking(0)
- if source is not None:
- s.bind(source)
- _wait_for_writable(s, expiration)
- s.sendto(wire, destination)
- while 1:
- _wait_for_readable(s, expiration)
- (wire, from_address) = s.recvfrom(65535)
- if _addresses_equal(af, from_address, destination) or \
- (dns.inet.is_multicast(where) and \
- from_address[1:] == destination[1:]):
- break
- if not ignore_unexpected:
- raise UnexpectedSource('got a response from '
- '%s instead of %s' % (from_address,
- destination))
- finally:
- s.close()
- r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
- one_rr_per_rrset=one_rr_per_rrset)
- if not q.is_response(r):
- raise BadResponse
- return r
-
-def _net_read(sock, count, expiration):
- """Read the specified number of bytes from sock. Keep trying until we
- either get the desired amount, or we hit EOF.
- A Timeout exception will be raised if the operation is not completed
- by the expiration time.
- """
- s = ''
- while count > 0:
- _wait_for_readable(sock, expiration)
- n = sock.recv(count)
- if n == '':
- raise EOFError
- count = count - len(n)
- s = s + n
- return s
-
-def _net_write(sock, data, expiration):
- """Write the specified data to the socket.
- A Timeout exception will be raised if the operation is not completed
- by the expiration time.
- """
- current = 0
- l = len(data)
- while current < l:
- _wait_for_writable(sock, expiration)
- current += sock.send(data[current:])
-
-def _connect(s, address):
- try:
- s.connect(address)
- except socket.error:
- (ty, v) = sys.exc_info()[:2]
- if v[0] != errno.EINPROGRESS and \
- v[0] != errno.EWOULDBLOCK and \
- v[0] != errno.EALREADY:
- raise v
-
-def tcp(q, where, timeout=None, port=53, af=None, source=None, source_port=0,
- one_rr_per_rrset=False):
- """Return the response obtained after sending a query via TCP.
-
- @param q: the query
- @type q: dns.message.Message object
- @param where: where to send the message
- @type where: string containing an IPv4 or IPv6 address
- @param timeout: The number of seconds to wait before the query times out.
- If None, the default, wait forever.
- @type timeout: float
- @param port: The port to which to send the message. The default is 53.
- @type port: int
- @param af: the address family to use. The default is None, which
- causes the address family to use to be inferred from the form of of where.
- If the inference attempt fails, AF_INET is used.
- @type af: int
- @rtype: dns.message.Message object
- @param source: source address. The default is the IPv4 wildcard address.
- @type source: string
- @param source_port: The port from which to send the message.
- The default is 0.
- @type source_port: int
- @param one_rr_per_rrset: Put each RR into its own RRset
- @type one_rr_per_rrset: bool
- """
-
- wire = q.to_wire()
- if af is None:
- try:
- af = dns.inet.af_for_address(where)
- except:
- af = dns.inet.AF_INET
- if af == dns.inet.AF_INET:
- destination = (where, port)
- if source is not None:
- source = (source, source_port)
- elif af == dns.inet.AF_INET6:
- destination = (where, port, 0, 0)
- if source is not None:
- source = (source, source_port, 0, 0)
- s = socket.socket(af, socket.SOCK_STREAM, 0)
- try:
- expiration = _compute_expiration(timeout)
- s.setblocking(0)
- if source is not None:
- s.bind(source)
- _connect(s, destination)
-
- l = len(wire)
-
- # copying the wire into tcpmsg is inefficient, but lets us
- # avoid writev() or doing a short write that would get pushed
- # onto the net
- tcpmsg = struct.pack("!H", l) + wire
- _net_write(s, tcpmsg, expiration)
- ldata = _net_read(s, 2, expiration)
- (l,) = struct.unpack("!H", ldata)
- wire = _net_read(s, l, expiration)
- finally:
- s.close()
- r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
- one_rr_per_rrset=one_rr_per_rrset)
- if not q.is_response(r):
- raise BadResponse
- return r
-
-def xfr(where, zone, rdtype=dns.rdatatype.AXFR, rdclass=dns.rdataclass.IN,
- timeout=None, port=53, keyring=None, keyname=None, relativize=True,
- af=None, lifetime=None, source=None, source_port=0, serial=0,
- use_udp=False, keyalgorithm=dns.tsig.default_algorithm):
- """Return a generator for the responses to a zone transfer.
-
- @param where: where to send the message
- @type where: string containing an IPv4 or IPv6 address
- @param zone: The name of the zone to transfer
- @type zone: dns.name.Name object or string
- @param rdtype: The type of zone transfer. The default is
- dns.rdatatype.AXFR.
- @type rdtype: int or string
- @param rdclass: The class of the zone transfer. The default is
- dns.rdatatype.IN.
- @type rdclass: int or string
- @param timeout: The number of seconds to wait for each response message.
- If None, the default, wait forever.
- @type timeout: float
- @param port: The port to which to send the message. The default is 53.
- @type port: int
- @param keyring: The TSIG keyring to use
- @type keyring: dict
- @param keyname: The name of the TSIG key to use
- @type keyname: dns.name.Name object or string
- @param relativize: If True, all names in the zone will be relativized to
- the zone origin. It is essential that the relativize setting matches
- the one specified to dns.zone.from_xfr().
- @type relativize: bool
- @param af: the address family to use. The default is None, which
- causes the address family to use to be inferred from the form of of where.
- If the inference attempt fails, AF_INET is used.
- @type af: int
- @param lifetime: The total number of seconds to spend doing the transfer.
- If None, the default, then there is no limit on the time the transfer may
- take.
- @type lifetime: float
- @rtype: generator of dns.message.Message objects.
- @param source: source address. The default is the IPv4 wildcard address.
- @type source: string
- @param source_port: The port from which to send the message.
- The default is 0.
- @type source_port: int
- @param serial: The SOA serial number to use as the base for an IXFR diff
- sequence (only meaningful if rdtype == dns.rdatatype.IXFR).
- @type serial: int
- @param use_udp: Use UDP (only meaningful for IXFR)
- @type use_udp: bool
- @param keyalgorithm: The TSIG algorithm to use; defaults to
- dns.tsig.default_algorithm
- @type keyalgorithm: string
- """
-
- if isinstance(zone, (str, unicode)):
- zone = dns.name.from_text(zone)
- if isinstance(rdtype, (str, unicode)):
- rdtype = dns.rdatatype.from_text(rdtype)
- q = dns.message.make_query(zone, rdtype, rdclass)
- if rdtype == dns.rdatatype.IXFR:
- rrset = dns.rrset.from_text(zone, 0, 'IN', 'SOA',
- '. . %u 0 0 0 0' % serial)
- q.authority.append(rrset)
- if not keyring is None:
- q.use_tsig(keyring, keyname, algorithm=keyalgorithm)
- wire = q.to_wire()
- if af is None:
- try:
- af = dns.inet.af_for_address(where)
- except:
- af = dns.inet.AF_INET
- if af == dns.inet.AF_INET:
- destination = (where, port)
- if source is not None:
- source = (source, source_port)
- elif af == dns.inet.AF_INET6:
- destination = (where, port, 0, 0)
- if source is not None:
- source = (source, source_port, 0, 0)
- if use_udp:
- if rdtype != dns.rdatatype.IXFR:
- raise ValueError('cannot do a UDP AXFR')
- s = socket.socket(af, socket.SOCK_DGRAM, 0)
- else:
- s = socket.socket(af, socket.SOCK_STREAM, 0)
- s.setblocking(0)
- if source is not None:
- s.bind(source)
- expiration = _compute_expiration(lifetime)
- _connect(s, destination)
- l = len(wire)
- if use_udp:
- _wait_for_writable(s, expiration)
- s.send(wire)
- else:
- tcpmsg = struct.pack("!H", l) + wire
- _net_write(s, tcpmsg, expiration)
- done = False
- soa_rrset = None
- soa_count = 0
- if relativize:
- origin = zone
- oname = dns.name.empty
- else:
- origin = None
- oname = zone
- tsig_ctx = None
- first = True
- while not done:
- mexpiration = _compute_expiration(timeout)
- if mexpiration is None or mexpiration > expiration:
- mexpiration = expiration
- if use_udp:
- _wait_for_readable(s, expiration)
- (wire, from_address) = s.recvfrom(65535)
- else:
- ldata = _net_read(s, 2, mexpiration)
- (l,) = struct.unpack("!H", ldata)
- wire = _net_read(s, l, mexpiration)
- r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
- xfr=True, origin=origin, tsig_ctx=tsig_ctx,
- multi=True, first=first,
- one_rr_per_rrset=(rdtype==dns.rdatatype.IXFR))
- tsig_ctx = r.tsig_ctx
- first = False
- answer_index = 0
- delete_mode = False
- expecting_SOA = False
- if soa_rrset is None:
- if not r.answer or r.answer[0].name != oname:
- raise dns.exception.FormError
- rrset = r.answer[0]
- if rrset.rdtype != dns.rdatatype.SOA:
- raise dns.exception.FormError("first RRset is not an SOA")
- answer_index = 1
- soa_rrset = rrset.copy()
- if rdtype == dns.rdatatype.IXFR:
- if soa_rrset[0].serial == serial:
- #
- # We're already up-to-date.
- #
- done = True
- else:
- expecting_SOA = True
- #
- # Process SOAs in the answer section (other than the initial
- # SOA in the first message).
- #
- for rrset in r.answer[answer_index:]:
- if done:
- raise dns.exception.FormError("answers after final SOA")
- if rrset.rdtype == dns.rdatatype.SOA and rrset.name == oname:
- if expecting_SOA:
- if rrset[0].serial != serial:
- raise dns.exception.FormError("IXFR base serial mismatch")
- expecting_SOA = False
- elif rdtype == dns.rdatatype.IXFR:
- delete_mode = not delete_mode
- if rrset == soa_rrset and not delete_mode:
- done = True
- elif expecting_SOA:
- #
- # We made an IXFR request and are expecting another
- # SOA RR, but saw something else, so this must be an
- # AXFR response.
- #
- rdtype = dns.rdatatype.AXFR
- expecting_SOA = False
- if done and q.keyring and not r.had_tsig:
- raise dns.exception.FormError("missing TSIG")
- yield r
- s.close()
git.samba.org / vlendec / samba-autobuild / .git / blobdiff