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Diffstat (limited to 'third_party/dnspython/dns/zone.py')
| -rw-r--r-- | third_party/dnspython/dns/zone.py | 855 |
1 files changed, 855 insertions, 0 deletions
diff --git a/third_party/dnspython/dns/zone.py b/third_party/dnspython/dns/zone.py new file mode 100644 index 0000000000..67c952d3cc --- /dev/null +++ b/third_party/dnspython/dns/zone.py @@ -0,0 +1,855 @@ +# 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. + +"""DNS Zones.""" + +from __future__ import generators + +import sys + +import dns.exception +import dns.name +import dns.node +import dns.rdataclass +import dns.rdatatype +import dns.rdata +import dns.rrset +import dns.tokenizer +import dns.ttl + +class BadZone(dns.exception.DNSException): + """The zone is malformed.""" + pass + +class NoSOA(BadZone): + """The zone has no SOA RR at its origin.""" + pass + +class NoNS(BadZone): + """The zone has no NS RRset at its origin.""" + pass + +class UnknownOrigin(BadZone): + """The zone's origin is unknown.""" + pass + +class Zone(object): + """A DNS zone. + + A Zone is a mapping from names to nodes. The zone object may be + treated like a Python dictionary, e.g. zone[name] will retrieve + the node associated with that name. The I{name} may be a + dns.name.Name object, or it may be a string. In the either case, + if the name is relative it is treated as relative to the origin of + the zone. + + @ivar rdclass: The zone's rdata class; the default is class IN. + @type rdclass: int + @ivar origin: The origin of the zone. + @type origin: dns.name.Name object + @ivar nodes: A dictionary mapping the names of nodes in the zone to the + nodes themselves. + @type nodes: dict + @ivar relativize: should names in the zone be relativized? + @type relativize: bool + @cvar node_factory: the factory used to create a new node + @type node_factory: class or callable + """ + + node_factory = dns.node.Node + + __slots__ = ['rdclass', 'origin', 'nodes', 'relativize'] + + def __init__(self, origin, rdclass=dns.rdataclass.IN, relativize=True): + """Initialize a zone object. + + @param origin: The origin of the zone. + @type origin: dns.name.Name object + @param rdclass: The zone's rdata class; the default is class IN. + @type rdclass: int""" + + self.rdclass = rdclass + self.origin = origin + self.nodes = {} + self.relativize = relativize + + def __eq__(self, other): + """Two zones are equal if they have the same origin, class, and + nodes. + @rtype: bool + """ + + if not isinstance(other, Zone): + return False + if self.rdclass != other.rdclass or \ + self.origin != other.origin or \ + self.nodes != other.nodes: + return False + return True + + def __ne__(self, other): + """Are two zones not equal? + @rtype: bool + """ + + return not self.__eq__(other) + + def _validate_name(self, name): + if isinstance(name, (str, unicode)): + name = dns.name.from_text(name, None) + elif not isinstance(name, dns.name.Name): + raise KeyError("name parameter must be convertable to a DNS name") + if name.is_absolute(): + if not name.is_subdomain(self.origin): + raise KeyError("name parameter must be a subdomain of the zone origin") + if self.relativize: + name = name.relativize(self.origin) + return name + + def __getitem__(self, key): + key = self._validate_name(key) + return self.nodes[key] + + def __setitem__(self, key, value): + key = self._validate_name(key) + self.nodes[key] = value + + def __delitem__(self, key): + key = self._validate_name(key) + del self.nodes[key] + + def __iter__(self): + return self.nodes.iterkeys() + + def iterkeys(self): + return self.nodes.iterkeys() + + def keys(self): + return self.nodes.keys() + + def itervalues(self): + return self.nodes.itervalues() + + def values(self): + return self.nodes.values() + + def iteritems(self): + return self.nodes.iteritems() + + def items(self): + return self.nodes.items() + + def get(self, key): + key = self._validate_name(key) + return self.nodes.get(key) + + def __contains__(self, other): + return other in self.nodes + + def find_node(self, name, create=False): + """Find a node in the zone, possibly creating it. + + @param name: the name of the node to find + @type name: dns.name.Name object or string + @param create: should the node be created if it doesn't exist? + @type create: bool + @raises KeyError: the name is not known and create was not specified. + @rtype: dns.node.Node object + """ + + name = self._validate_name(name) + node = self.nodes.get(name) + if node is None: + if not create: + raise KeyError + node = self.node_factory() + self.nodes[name] = node + return node + + def get_node(self, name, create=False): + """Get a node in the zone, possibly creating it. + + This method is like L{find_node}, except it returns None instead + of raising an exception if the node does not exist and creation + has not been requested. + + @param name: the name of the node to find + @type name: dns.name.Name object or string + @param create: should the node be created if it doesn't exist? + @type create: bool + @rtype: dns.node.Node object or None + """ + + try: + node = self.find_node(name, create) + except KeyError: + node = None + return node + + def delete_node(self, name): + """Delete the specified node if it exists. + + It is not an error if the node does not exist. + """ + + name = self._validate_name(name) + if self.nodes.has_key(name): + del self.nodes[name] + + def find_rdataset(self, name, rdtype, covers=dns.rdatatype.NONE, + create=False): + """Look for rdata with the specified name and type in the zone, + and return an rdataset encapsulating it. + + The I{name}, I{rdtype}, and I{covers} parameters may be + strings, in which case they will be converted to their proper + type. + + The rdataset returned is not a copy; changes to it will change + the zone. + + KeyError is raised if the name or type are not found. + Use L{get_rdataset} if you want to have None returned instead. + + @param name: the owner name to look for + @type name: DNS.name.Name object or string + @param rdtype: the rdata type desired + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + @param create: should the node and rdataset be created if they do not + exist? + @type create: bool + @raises KeyError: the node or rdata could not be found + @rtype: dns.rrset.RRset object + """ + + name = self._validate_name(name) + if isinstance(rdtype, (str, unicode)): + rdtype = dns.rdatatype.from_text(rdtype) + if isinstance(covers, (str, unicode)): + covers = dns.rdatatype.from_text(covers) + node = self.find_node(name, create) + return node.find_rdataset(self.rdclass, rdtype, covers, create) + + def get_rdataset(self, name, rdtype, covers=dns.rdatatype.NONE, + create=False): + """Look for rdata with the specified name and type in the zone, + and return an rdataset encapsulating it. + + The I{name}, I{rdtype}, and I{covers} parameters may be + strings, in which case they will be converted to their proper + type. + + The rdataset returned is not a copy; changes to it will change + the zone. + + None is returned if the name or type are not found. + Use L{find_rdataset} if you want to have KeyError raised instead. + + @param name: the owner name to look for + @type name: DNS.name.Name object or string + @param rdtype: the rdata type desired + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + @param create: should the node and rdataset be created if they do not + exist? + @type create: bool + @rtype: dns.rrset.RRset object + """ + + try: + rdataset = self.find_rdataset(name, rdtype, covers, create) + except KeyError: + rdataset = None + return rdataset + + def delete_rdataset(self, name, rdtype, covers=dns.rdatatype.NONE): + """Delete the rdataset matching I{rdtype} and I{covers}, if it + exists at the node specified by I{name}. + + The I{name}, I{rdtype}, and I{covers} parameters may be + strings, in which case they will be converted to their proper + type. + + It is not an error if the node does not exist, or if there is no + matching rdataset at the node. + + If the node has no rdatasets after the deletion, it will itself + be deleted. + + @param name: the owner name to look for + @type name: DNS.name.Name object or string + @param rdtype: the rdata type desired + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + """ + + name = self._validate_name(name) + if isinstance(rdtype, (str, unicode)): + rdtype = dns.rdatatype.from_text(rdtype) + if isinstance(covers, (str, unicode)): + covers = dns.rdatatype.from_text(covers) + node = self.get_node(name) + if not node is None: + node.delete_rdataset(self.rdclass, rdtype, covers) + if len(node) == 0: + self.delete_node(name) + + def replace_rdataset(self, name, replacement): + """Replace an rdataset at name. + + It is not an error if there is no rdataset matching I{replacement}. + + Ownership of the I{replacement} object is transferred to the zone; + in other words, this method does not store a copy of I{replacement} + at the node, it stores I{replacement} itself. + + If the I{name} node does not exist, it is created. + + @param name: the owner name + @type name: DNS.name.Name object or string + @param replacement: the replacement rdataset + @type replacement: dns.rdataset.Rdataset + """ + + if replacement.rdclass != self.rdclass: + raise ValueError('replacement.rdclass != zone.rdclass') + node = self.find_node(name, True) + node.replace_rdataset(replacement) + + def find_rrset(self, name, rdtype, covers=dns.rdatatype.NONE): + """Look for rdata with the specified name and type in the zone, + and return an RRset encapsulating it. + + The I{name}, I{rdtype}, and I{covers} parameters may be + strings, in which case they will be converted to their proper + type. + + This method is less efficient than the similar + L{find_rdataset} because it creates an RRset instead of + returning the matching rdataset. It may be more convenient + for some uses since it returns an object which binds the owner + name to the rdata. + + This method may not be used to create new nodes or rdatasets; + use L{find_rdataset} instead. + + KeyError is raised if the name or type are not found. + Use L{get_rrset} if you want to have None returned instead. + + @param name: the owner name to look for + @type name: DNS.name.Name object or string + @param rdtype: the rdata type desired + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + @raises KeyError: the node or rdata could not be found + @rtype: dns.rrset.RRset object + """ + + name = self._validate_name(name) + if isinstance(rdtype, (str, unicode)): + rdtype = dns.rdatatype.from_text(rdtype) + if isinstance(covers, (str, unicode)): + covers = dns.rdatatype.from_text(covers) + rdataset = self.nodes[name].find_rdataset(self.rdclass, rdtype, covers) + rrset = dns.rrset.RRset(name, self.rdclass, rdtype, covers) + rrset.update(rdataset) + return rrset + + def get_rrset(self, name, rdtype, covers=dns.rdatatype.NONE): + """Look for rdata with the specified name and type in the zone, + and return an RRset encapsulating it. + + The I{name}, I{rdtype}, and I{covers} parameters may be + strings, in which case they will be converted to their proper + type. + + This method is less efficient than the similar L{get_rdataset} + because it creates an RRset instead of returning the matching + rdataset. It may be more convenient for some uses since it + returns an object which binds the owner name to the rdata. + + This method may not be used to create new nodes or rdatasets; + use L{find_rdataset} instead. + + None is returned if the name or type are not found. + Use L{find_rrset} if you want to have KeyError raised instead. + + @param name: the owner name to look for + @type name: DNS.name.Name object or string + @param rdtype: the rdata type desired + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + @rtype: dns.rrset.RRset object + """ + + try: + rrset = self.find_rrset(name, rdtype, covers) + except KeyError: + rrset = None + return rrset + + def iterate_rdatasets(self, rdtype=dns.rdatatype.ANY, + covers=dns.rdatatype.NONE): + """Return a generator which yields (name, rdataset) tuples for + all rdatasets in the zone which have the specified I{rdtype} + and I{covers}. If I{rdtype} is dns.rdatatype.ANY, the default, + then all rdatasets will be matched. + + @param rdtype: int or string + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + """ + + if isinstance(rdtype, (str, unicode)): + rdtype = dns.rdatatype.from_text(rdtype) + if isinstance(covers, (str, unicode)): + covers = dns.rdatatype.from_text(covers) + for (name, node) in self.iteritems(): + for rds in node: + if rdtype == dns.rdatatype.ANY or \ + (rds.rdtype == rdtype and rds.covers == covers): + yield (name, rds) + + def iterate_rdatas(self, rdtype=dns.rdatatype.ANY, + covers=dns.rdatatype.NONE): + """Return a generator which yields (name, ttl, rdata) tuples for + all rdatas in the zone which have the specified I{rdtype} + and I{covers}. If I{rdtype} is dns.rdatatype.ANY, the default, + then all rdatas will be matched. + + @param rdtype: int or string + @type rdtype: int or string + @param covers: the covered type (defaults to None) + @type covers: int or string + """ + + if isinstance(rdtype, (str, unicode)): + rdtype = dns.rdatatype.from_text(rdtype) + if isinstance(covers, (str, unicode)): + covers = dns.rdatatype.from_text(covers) + for (name, node) in self.iteritems(): + for rds in node: + if rdtype == dns.rdatatype.ANY or \ + (rds.rdtype == rdtype and rds.covers == covers): + for rdata in rds: + yield (name, rds.ttl, rdata) + + def to_file(self, f, sorted=True, relativize=True, nl=None): + """Write a zone to a file. + + @param f: file or string. If I{f} is a string, it is treated + as the name of a file to open. + @param sorted: if True, the file will be written with the + names sorted in DNSSEC order from least to greatest. Otherwise + the names will be written in whatever order they happen to have + in the zone's dictionary. + @param relativize: if True, domain names in the output will be + relativized to the zone's origin (if possible). + @type relativize: bool + @param nl: The end of line string. If not specified, the + output will use the platform's native end-of-line marker (i.e. + LF on POSIX, CRLF on Windows, CR on Macintosh). + @type nl: string or None + """ + + if sys.hexversion >= 0x02030000: + # allow Unicode filenames + str_type = basestring + else: + str_type = str + if nl is None: + opts = 'w' + else: + opts = 'wb' + if isinstance(f, str_type): + f = file(f, opts) + want_close = True + else: + want_close = False + try: + if sorted: + names = self.keys() + names.sort() + else: + names = self.iterkeys() + for n in names: + l = self[n].to_text(n, origin=self.origin, + relativize=relativize) + if nl is None: + print >> f, l + else: + f.write(l) + f.write(nl) + finally: + if want_close: + f.close() + + def check_origin(self): + """Do some simple checking of the zone's origin. + + @raises dns.zone.NoSOA: there is no SOA RR + @raises dns.zone.NoNS: there is no NS RRset + @raises KeyError: there is no origin node + """ + if self.relativize: + name = dns.name.empty + else: + name = self.origin + if self.get_rdataset(name, dns.rdatatype.SOA) is None: + raise NoSOA + if self.get_rdataset(name, dns.rdatatype.NS) is None: + raise NoNS + + +class _MasterReader(object): + """Read a DNS master file + + @ivar tok: The tokenizer + @type tok: dns.tokenizer.Tokenizer object + @ivar ttl: The default TTL + @type ttl: int + @ivar last_name: The last name read + @type last_name: dns.name.Name object + @ivar current_origin: The current origin + @type current_origin: dns.name.Name object + @ivar relativize: should names in the zone be relativized? + @type relativize: bool + @ivar zone: the zone + @type zone: dns.zone.Zone object + @ivar saved_state: saved reader state (used when processing $INCLUDE) + @type saved_state: list of (tokenizer, current_origin, last_name, file) + tuples. + @ivar current_file: the file object of the $INCLUDed file being parsed + (None if no $INCLUDE is active). + @ivar allow_include: is $INCLUDE allowed? + @type allow_include: bool + @ivar check_origin: should sanity checks of the origin node be done? + The default is True. + @type check_origin: bool + """ + + def __init__(self, tok, origin, rdclass, relativize, zone_factory=Zone, + allow_include=False, check_origin=True): + if isinstance(origin, (str, unicode)): + origin = dns.name.from_text(origin) + self.tok = tok + self.current_origin = origin + self.relativize = relativize + self.ttl = 0 + self.last_name = None + self.zone = zone_factory(origin, rdclass, relativize=relativize) + self.saved_state = [] + self.current_file = None + self.allow_include = allow_include + self.check_origin = check_origin + + def _eat_line(self): + while 1: + token = self.tok.get() + if token.is_eol_or_eof(): + break + + def _rr_line(self): + """Process one line from a DNS master file.""" + # Name + if self.current_origin is None: + raise UnknownOrigin + token = self.tok.get(want_leading = True) + if not token.is_whitespace(): + self.last_name = dns.name.from_text(token.value, self.current_origin) + else: + token = self.tok.get() + if token.is_eol_or_eof(): + # treat leading WS followed by EOL/EOF as if they were EOL/EOF. + return + self.tok.unget(token) + name = self.last_name + if not name.is_subdomain(self.zone.origin): + self._eat_line() + return + if self.relativize: + name = name.relativize(self.zone.origin) + token = self.tok.get() + if not token.is_identifier(): + raise dns.exception.SyntaxError + # TTL + try: + ttl = dns.ttl.from_text(token.value) + token = self.tok.get() + if not token.is_identifier(): + raise dns.exception.SyntaxError + except dns.ttl.BadTTL: + ttl = self.ttl + # Class + try: + rdclass = dns.rdataclass.from_text(token.value) + token = self.tok.get() + if not token.is_identifier(): + raise dns.exception.SyntaxError + except dns.exception.SyntaxError: + raise dns.exception.SyntaxError + except: + rdclass = self.zone.rdclass + if rdclass != self.zone.rdclass: + raise dns.exception.SyntaxError("RR class is not zone's class") + # Type + try: + rdtype = dns.rdatatype.from_text(token.value) + except: + raise dns.exception.SyntaxError("unknown rdatatype '%s'" % token.value) + n = self.zone.nodes.get(name) + if n is None: + n = self.zone.node_factory() + self.zone.nodes[name] = n + try: + rd = dns.rdata.from_text(rdclass, rdtype, self.tok, + self.current_origin, False) + except dns.exception.SyntaxError: + # Catch and reraise. + (ty, va) = sys.exc_info()[:2] + raise va + except: + # All exceptions that occur in the processing of rdata + # are treated as syntax errors. This is not strictly + # correct, but it is correct almost all of the time. + # We convert them to syntax errors so that we can emit + # helpful filename:line info. + (ty, va) = sys.exc_info()[:2] + raise dns.exception.SyntaxError("caught exception %s: %s" % (str(ty), str(va))) + + rd.choose_relativity(self.zone.origin, self.relativize) + covers = rd.covers() + rds = n.find_rdataset(rdclass, rdtype, covers, True) + rds.add(rd, ttl) + + def read(self): + """Read a DNS master file and build a zone object. + + @raises dns.zone.NoSOA: No SOA RR was found at the zone origin + @raises dns.zone.NoNS: No NS RRset was found at the zone origin + """ + + try: + while 1: + token = self.tok.get(True, True).unescape() + if token.is_eof(): + if not self.current_file is None: + self.current_file.close() + if len(self.saved_state) > 0: + (self.tok, + self.current_origin, + self.last_name, + self.current_file, + self.ttl) = self.saved_state.pop(-1) + continue + break + elif token.is_eol(): + continue + elif token.is_comment(): + self.tok.get_eol() + continue + elif token.value[0] == '$': + u = token.value.upper() + if u == '$TTL': + token = self.tok.get() + if not token.is_identifier(): + raise dns.exception.SyntaxError("bad $TTL") + self.ttl = dns.ttl.from_text(token.value) + self.tok.get_eol() + elif u == '$ORIGIN': + self.current_origin = self.tok.get_name() + self.tok.get_eol() + if self.zone.origin is None: + self.zone.origin = self.current_origin + elif u == '$INCLUDE' and self.allow_include: + token = self.tok.get() + if not token.is_quoted_string(): + raise dns.exception.SyntaxError("bad filename in $INCLUDE") + filename = token.value + token = self.tok.get() + if token.is_identifier(): + new_origin = dns.name.from_text(token.value, \ + self.current_origin) + self.tok.get_eol() + elif not token.is_eol_or_eof(): + raise dns.exception.SyntaxError("bad origin in $INCLUDE") + else: + new_origin = self.current_origin + self.saved_state.append((self.tok, + self.current_origin, + self.last_name, + self.current_file, + self.ttl)) + self.current_file = file(filename, 'r') + self.tok = dns.tokenizer.Tokenizer(self.current_file, + filename) + self.current_origin = new_origin + else: + raise dns.exception.SyntaxError("Unknown master file directive '" + u + "'") + continue + self.tok.unget(token) + self._rr_line() + except dns.exception.SyntaxError, detail: + (filename, line_number) = self.tok.where() + if detail is None: + detail = "syntax error" + raise dns.exception.SyntaxError("%s:%d: %s" % (filename, line_number, detail)) + + # Now that we're done reading, do some basic checking of the zone. + if self.check_origin: + self.zone.check_origin() + +def from_text(text, origin = None, rdclass = dns.rdataclass.IN, + relativize = True, zone_factory=Zone, filename=None, + allow_include=False, check_origin=True): + """Build a zone object from a master file format string. + + @param text: the master file format input + @type text: string. + @param origin: The origin of the zone; if not specified, the first + $ORIGIN statement in the master file will determine the origin of the + zone. + @type origin: dns.name.Name object or string + @param rdclass: The zone's rdata class; the default is class IN. + @type rdclass: int + @param relativize: should names be relativized? The default is True + @type relativize: bool + @param zone_factory: The zone factory to use + @type zone_factory: function returning a Zone + @param filename: The filename to emit when describing where an error + occurred; the default is '<string>'. + @type filename: string + @param allow_include: is $INCLUDE allowed? + @type allow_include: bool + @param check_origin: should sanity checks of the origin node be done? + The default is True. + @type check_origin: bool + @raises dns.zone.NoSOA: No SOA RR was found at the zone origin + @raises dns.zone.NoNS: No NS RRset was found at the zone origin + @rtype: dns.zone.Zone object + """ + + # 'text' can also be a file, but we don't publish that fact + # since it's an implementation detail. The official file + # interface is from_file(). + + if filename is None: + filename = '<string>' + tok = dns.tokenizer.Tokenizer(text, filename) + reader = _MasterReader(tok, origin, rdclass, relativize, zone_factory, + allow_include=allow_include, + check_origin=check_origin) + reader.read() + return reader.zone + +def from_file(f, origin = None, rdclass = dns.rdataclass.IN, + relativize = True, zone_factory=Zone, filename=None, + allow_include=True, check_origin=True): + """Read a master file and build a zone object. + + @param f: file or string. If I{f} is a string, it is treated + as the name of a file to open. + @param origin: The origin of the zone; if not specified, the first + $ORIGIN statement in the master file will determine the origin of the + zone. + @type origin: dns.name.Name object or string + @param rdclass: The zone's rdata class; the default is class IN. + @type rdclass: int + @param relativize: should names be relativized? The default is True + @type relativize: bool + @param zone_factory: The zone factory to use + @type zone_factory: function returning a Zone + @param filename: The filename to emit when describing where an error + occurred; the default is '<file>', or the value of I{f} if I{f} is a + string. + @type filename: string + @param allow_include: is $INCLUDE allowed? + @type allow_include: bool + @param check_origin: should sanity checks of the origin node be done? + The default is True. + @type check_origin: bool + @raises dns.zone.NoSOA: No SOA RR was found at the zone origin + @raises dns.zone.NoNS: No NS RRset was found at the zone origin + @rtype: dns.zone.Zone object + """ + + if sys.hexversion >= 0x02030000: + # allow Unicode filenames; turn on universal newline support + str_type = basestring + opts = 'rU' + else: + str_type = str + opts = 'r' + if isinstance(f, str_type): + if filename is None: + filename = f + f = file(f, opts) + want_close = True + else: + if filename is None: + filename = '<file>' + want_close = False + + try: + z = from_text(f, origin, rdclass, relativize, zone_factory, + filename, allow_include, check_origin) + finally: + if want_close: + f.close() + return z + +def from_xfr(xfr, zone_factory=Zone, relativize=True): + """Convert the output of a zone transfer generator into a zone object. + + @param xfr: The xfr generator + @type xfr: generator of dns.message.Message objects + @param relativize: should names be relativized? The default is True. + It is essential that the relativize setting matches the one specified + to dns.query.xfr(). + @type relativize: bool + @raises dns.zone.NoSOA: No SOA RR was found at the zone origin + @raises dns.zone.NoNS: No NS RRset was found at the zone origin + @rtype: dns.zone.Zone object + """ + + z = None + for r in xfr: + if z is None: + if relativize: + origin = r.origin + else: + origin = r.answer[0].name + rdclass = r.answer[0].rdclass + z = zone_factory(origin, rdclass, relativize=relativize) + for rrset in r.answer: + znode = z.nodes.get(rrset.name) + if not znode: + znode = z.node_factory() + z.nodes[rrset.name] = znode + zrds = znode.find_rdataset(rrset.rdclass, rrset.rdtype, + rrset.covers, True) + zrds.update_ttl(rrset.ttl) + for rd in rrset: + rd.choose_relativity(z.origin, relativize) + zrds.add(rd) + z.check_origin() + return z |