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Diffstat (limited to 'third_party/dnspython/dns/renderer.py')
| -rw-r--r-- | third_party/dnspython/dns/renderer.py | 325 |
1 files changed, 0 insertions, 325 deletions
diff --git a/third_party/dnspython/dns/renderer.py b/third_party/dnspython/dns/renderer.py deleted file mode 100644 index ad3f83d450e..00000000000 --- a/third_party/dnspython/dns/renderer.py +++ /dev/null @@ -1,325 +0,0 @@ -# Copyright (C) 2001-2007, 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. - -"""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. - @type request_mac: string - @param algorithm: the TSIG algorithm to use - @type algorithm: dns.name.Name object - """ - - 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() |