| Index: Tools/Scripts/webkitpy/thirdparty/webpagereplay/third_party/dns/renderer.py
|
| diff --git a/Tools/Scripts/webkitpy/thirdparty/webpagereplay/third_party/dns/renderer.py b/Tools/Scripts/webkitpy/thirdparty/webpagereplay/third_party/dns/renderer.py
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..bb0218ac301d81ec0b993fff56d2c9a3e2b44812
|
| --- /dev/null
|
| +++ b/Tools/Scripts/webkitpy/thirdparty/webpagereplay/third_party/dns/renderer.py
|
| @@ -0,0 +1,324 @@
|
| +# Copyright (C) 2001-2007, 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.
|
| +
|
| +"""Help for building DNS wire format messages"""
|
| +
|
| +import cStringIO
|
| +import struct
|
| +import random
|
| +import time
|
| +
|
| +import dns.exception
|
| +import dns.tsig
|
| +
|
| +QUESTION = 0
|
| +ANSWER = 1
|
| +AUTHORITY = 2
|
| +ADDITIONAL = 3
|
| +
|
| +class Renderer(object):
|
| + """Helper class for building DNS wire-format messages.
|
| +
|
| + Most applications can use the higher-level L{dns.message.Message}
|
| + class and its to_wire() method to generate wire-format messages.
|
| + This class is for those applications which need finer control
|
| + over the generation of messages.
|
| +
|
| + Typical use::
|
| +
|
| + r = dns.renderer.Renderer(id=1, flags=0x80, max_size=512)
|
| + r.add_question(qname, qtype, qclass)
|
| + r.add_rrset(dns.renderer.ANSWER, rrset_1)
|
| + r.add_rrset(dns.renderer.ANSWER, rrset_2)
|
| + r.add_rrset(dns.renderer.AUTHORITY, ns_rrset)
|
| + r.add_edns(0, 0, 4096)
|
| + r.add_rrset(dns.renderer.ADDTIONAL, ad_rrset_1)
|
| + r.add_rrset(dns.renderer.ADDTIONAL, ad_rrset_2)
|
| + r.write_header()
|
| + r.add_tsig(keyname, secret, 300, 1, 0, '', request_mac)
|
| + wire = r.get_wire()
|
| +
|
| + @ivar output: where rendering is written
|
| + @type output: cStringIO.StringIO object
|
| + @ivar id: the message id
|
| + @type id: int
|
| + @ivar flags: the message flags
|
| + @type flags: int
|
| + @ivar max_size: the maximum size of the message
|
| + @type max_size: int
|
| + @ivar origin: the origin to use when rendering relative names
|
| + @type origin: dns.name.Name object
|
| + @ivar compress: the compression table
|
| + @type compress: dict
|
| + @ivar section: the section currently being rendered
|
| + @type section: int (dns.renderer.QUESTION, dns.renderer.ANSWER,
|
| + dns.renderer.AUTHORITY, or dns.renderer.ADDITIONAL)
|
| + @ivar counts: list of the number of RRs in each section
|
| + @type counts: int list of length 4
|
| + @ivar mac: the MAC of the rendered message (if TSIG was used)
|
| + @type mac: string
|
| + """
|
| +
|
| + def __init__(self, id=None, flags=0, max_size=65535, origin=None):
|
| + """Initialize a new renderer.
|
| +
|
| + @param id: the message id
|
| + @type id: int
|
| + @param flags: the DNS message flags
|
| + @type flags: int
|
| + @param max_size: the maximum message size; the default is 65535.
|
| + If rendering results in a message greater than I{max_size},
|
| + then L{dns.exception.TooBig} will be raised.
|
| + @type max_size: int
|
| + @param origin: the origin to use when rendering relative names
|
| + @type origin: dns.name.Namem or None.
|
| + """
|
| +
|
| + self.output = cStringIO.StringIO()
|
| + if id is None:
|
| + self.id = random.randint(0, 65535)
|
| + else:
|
| + self.id = id
|
| + self.flags = flags
|
| + self.max_size = max_size
|
| + self.origin = origin
|
| + self.compress = {}
|
| + self.section = QUESTION
|
| + self.counts = [0, 0, 0, 0]
|
| + self.output.write('\x00' * 12)
|
| + self.mac = ''
|
| +
|
| + def _rollback(self, where):
|
| + """Truncate the output buffer at offset I{where}, and remove any
|
| + compression table entries that pointed beyond the truncation
|
| + point.
|
| +
|
| + @param where: the offset
|
| + @type where: int
|
| + """
|
| +
|
| + self.output.seek(where)
|
| + self.output.truncate()
|
| + keys_to_delete = []
|
| + for k, v in self.compress.iteritems():
|
| + if v >= where:
|
| + keys_to_delete.append(k)
|
| + for k in keys_to_delete:
|
| + del self.compress[k]
|
| +
|
| + def _set_section(self, section):
|
| + """Set the renderer's current section.
|
| +
|
| + Sections must be rendered order: QUESTION, ANSWER, AUTHORITY,
|
| + ADDITIONAL. Sections may be empty.
|
| +
|
| + @param section: the section
|
| + @type section: int
|
| + @raises dns.exception.FormError: an attempt was made to set
|
| + a section value less than the current section.
|
| + """
|
| +
|
| + if self.section != section:
|
| + if self.section > section:
|
| + raise dns.exception.FormError
|
| + self.section = section
|
| +
|
| + def add_question(self, qname, rdtype, rdclass=dns.rdataclass.IN):
|
| + """Add a question to the message.
|
| +
|
| + @param qname: the question name
|
| + @type qname: dns.name.Name
|
| + @param rdtype: the question rdata type
|
| + @type rdtype: int
|
| + @param rdclass: the question rdata class
|
| + @type rdclass: int
|
| + """
|
| +
|
| + self._set_section(QUESTION)
|
| + before = self.output.tell()
|
| + qname.to_wire(self.output, self.compress, self.origin)
|
| + self.output.write(struct.pack("!HH", rdtype, rdclass))
|
| + after = self.output.tell()
|
| + if after >= self.max_size:
|
| + self._rollback(before)
|
| + raise dns.exception.TooBig
|
| + self.counts[QUESTION] += 1
|
| +
|
| + def add_rrset(self, section, rrset, **kw):
|
| + """Add the rrset to the specified section.
|
| +
|
| + Any keyword arguments are passed on to the rdataset's to_wire()
|
| + routine.
|
| +
|
| + @param section: the section
|
| + @type section: int
|
| + @param rrset: the rrset
|
| + @type rrset: dns.rrset.RRset object
|
| + """
|
| +
|
| + self._set_section(section)
|
| + before = self.output.tell()
|
| + n = rrset.to_wire(self.output, self.compress, self.origin, **kw)
|
| + after = self.output.tell()
|
| + if after >= self.max_size:
|
| + self._rollback(before)
|
| + raise dns.exception.TooBig
|
| + self.counts[section] += n
|
| +
|
| + def add_rdataset(self, section, name, rdataset, **kw):
|
| + """Add the rdataset to the specified section, using the specified
|
| + name as the owner name.
|
| +
|
| + Any keyword arguments are passed on to the rdataset's to_wire()
|
| + routine.
|
| +
|
| + @param section: the section
|
| + @type section: int
|
| + @param name: the owner name
|
| + @type name: dns.name.Name object
|
| + @param rdataset: the rdataset
|
| + @type rdataset: dns.rdataset.Rdataset object
|
| + """
|
| +
|
| + self._set_section(section)
|
| + before = self.output.tell()
|
| + n = rdataset.to_wire(name, self.output, self.compress, self.origin,
|
| + **kw)
|
| + after = self.output.tell()
|
| + if after >= self.max_size:
|
| + self._rollback(before)
|
| + raise dns.exception.TooBig
|
| + self.counts[section] += n
|
| +
|
| + def add_edns(self, edns, ednsflags, payload, options=None):
|
| + """Add an EDNS OPT record to the message.
|
| +
|
| + @param edns: The EDNS level to use.
|
| + @type edns: int
|
| + @param ednsflags: EDNS flag values.
|
| + @type ednsflags: int
|
| + @param payload: The EDNS sender's payload field, which is the maximum
|
| + size of UDP datagram the sender can handle.
|
| + @type payload: int
|
| + @param options: The EDNS options list
|
| + @type options: list of dns.edns.Option instances
|
| + @see: RFC 2671
|
| + """
|
| +
|
| + # make sure the EDNS version in ednsflags agrees with edns
|
| + ednsflags &= 0xFF00FFFFL
|
| + ednsflags |= (edns << 16)
|
| + self._set_section(ADDITIONAL)
|
| + before = self.output.tell()
|
| + self.output.write(struct.pack('!BHHIH', 0, dns.rdatatype.OPT, payload,
|
| + ednsflags, 0))
|
| + if not options is None:
|
| + lstart = self.output.tell()
|
| + for opt in options:
|
| + stuff = struct.pack("!HH", opt.otype, 0)
|
| + self.output.write(stuff)
|
| + start = self.output.tell()
|
| + opt.to_wire(self.output)
|
| + end = self.output.tell()
|
| + assert end - start < 65536
|
| + self.output.seek(start - 2)
|
| + stuff = struct.pack("!H", end - start)
|
| + self.output.write(stuff)
|
| + self.output.seek(0, 2)
|
| + lend = self.output.tell()
|
| + assert lend - lstart < 65536
|
| + self.output.seek(lstart - 2)
|
| + stuff = struct.pack("!H", lend - lstart)
|
| + self.output.write(stuff)
|
| + self.output.seek(0, 2)
|
| + after = self.output.tell()
|
| + if after >= self.max_size:
|
| + self._rollback(before)
|
| + raise dns.exception.TooBig
|
| + self.counts[ADDITIONAL] += 1
|
| +
|
| + def add_tsig(self, keyname, secret, fudge, id, tsig_error, other_data,
|
| + request_mac, algorithm=dns.tsig.default_algorithm):
|
| + """Add a TSIG signature to the message.
|
| +
|
| + @param keyname: the TSIG key name
|
| + @type keyname: dns.name.Name object
|
| + @param secret: the secret to use
|
| + @type secret: string
|
| + @param fudge: TSIG time fudge
|
| + @type fudge: int
|
| + @param id: the message id to encode in the tsig signature
|
| + @type id: int
|
| + @param tsig_error: TSIG error code; default is 0.
|
| + @type tsig_error: int
|
| + @param other_data: TSIG other data.
|
| + @type other_data: string
|
| + @param request_mac: This message is a response to the request which
|
| + had the specified MAC.
|
| + @param algorithm: the TSIG algorithm to use
|
| + @type request_mac: string
|
| + """
|
| +
|
| + self._set_section(ADDITIONAL)
|
| + before = self.output.tell()
|
| + s = self.output.getvalue()
|
| + (tsig_rdata, self.mac, ctx) = dns.tsig.sign(s,
|
| + keyname,
|
| + secret,
|
| + int(time.time()),
|
| + fudge,
|
| + id,
|
| + tsig_error,
|
| + other_data,
|
| + request_mac,
|
| + algorithm=algorithm)
|
| + keyname.to_wire(self.output, self.compress, self.origin)
|
| + self.output.write(struct.pack('!HHIH', dns.rdatatype.TSIG,
|
| + dns.rdataclass.ANY, 0, 0))
|
| + rdata_start = self.output.tell()
|
| + self.output.write(tsig_rdata)
|
| + after = self.output.tell()
|
| + assert after - rdata_start < 65536
|
| + if after >= self.max_size:
|
| + self._rollback(before)
|
| + raise dns.exception.TooBig
|
| + self.output.seek(rdata_start - 2)
|
| + self.output.write(struct.pack('!H', after - rdata_start))
|
| + self.counts[ADDITIONAL] += 1
|
| + self.output.seek(10)
|
| + self.output.write(struct.pack('!H', self.counts[ADDITIONAL]))
|
| + self.output.seek(0, 2)
|
| +
|
| + def write_header(self):
|
| + """Write the DNS message header.
|
| +
|
| + Writing the DNS message header is done asfter all sections
|
| + have been rendered, but before the optional TSIG signature
|
| + is added.
|
| + """
|
| +
|
| + self.output.seek(0)
|
| + self.output.write(struct.pack('!HHHHHH', self.id, self.flags,
|
| + self.counts[0], self.counts[1],
|
| + self.counts[2], self.counts[3]))
|
| + self.output.seek(0, 2)
|
| +
|
| + def get_wire(self):
|
| + """Return the wire format message.
|
| +
|
| + @rtype: string
|
| + """
|
| +
|
| + return self.output.getvalue()
|
|
|