Check in the thirdparty libs needed for webkitpy.

Tools/Scripts/webkitpy/thirdparty/webpagereplay/third_party/dns/query.py

+# Copyright (C) 2003-2007, 2009, 2010 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 _wait_for(ir, iw, ix, 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 timeout is None:
+                (r, w, x) = select.select(ir, iw, ix)
+            else:
+                (r, w, x) = select.select(ir, iw, ix, timeout)
+        except select.error, e:
+            if e.args[0] != errno.EINTR:
+                raise e
+        done = True
+        if len(r) == 0 and len(w) == 0 and len(x) == 0:
+            raise dns.exception.Timeout
+
+def _wait_for_readable(s, expiration):
+    _wait_for([s], [], [s], expiration)
+
+def _wait_for_writable(s, expiration):
+    _wait_for([], [s], [s], 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):
+        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()