def delete_rdataset(self, name, rdtype, covers=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 = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = 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 find_rdataset(self, name, rdtype, covers=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: rrset.RRset object
"""
name = self._validate_name(name)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
node = self.find_node(name, create)
return node.find_rdataset(self.rdclass, rdtype, covers, create)
def delete_rdataset(self, name, rdtype, covers=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 = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = 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 find_rdataset(self, name, rdtype, covers=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: rrset.RRset object
"""
name = self._validate_name(name)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
node = self.find_node(name, create)
return node.find_rdataset(self.rdclass, rdtype, covers, create)
def _question_line(self, section):
"""Process one line from the text format question section."""
token = self.tok.get(want_leading=True)
if not token.is_whitespace():
self.last_name = mname.from_text(token.value, None)
name = self.last_name
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = rdataclass.IN
# Type
rdtype = rdatatype.from_text(token.value)
self.message.find_rrset(self.message.question,
name,
rdclass,
rdtype,
create=True,
force_unique=True)
if self.updating:
self.zone_rdclass = rdclass
self.tok.get_eol()
def _question_line(self, section):
"""Process one line from the text format question section."""
token = self.tok.get(want_leading = True)
if not token.is_whitespace():
self.last_name = mname.from_text(token.value, None)
name = self.last_name
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = rdataclass.IN
# Type
rdtype = rdatatype.from_text(token.value)
self.message.find_rrset(self.message.question, name,
rdclass, rdtype, create=True,
force_unique=True)
if self.updating:
self.zone_rdclass = rdclass
self.tok.get_eol()
def make_query(qname,
rdtype,
rdclass=rdataclass.IN,
use_edns=None,
want_dnssec=False,
ednsflags=0,
payload=1280,
request_payload=None,
options=None):
"""Make a query message.
The query name, type, and class may all be specified either
as objects of the appropriate type, or as strings.
The query will have a randomly choosen query id, and its DNS flags
will be set to flags.RD.
@param qname: The query name.
@type qname: mname.Name object or string
@param rdtype: The desired rdata type.
@type rdtype: int
@param rdclass: The desired rdata class; the default is class IN.
@type rdclass: int
@param use_edns: The EDNS level to use; the default is None (no EDNS).
See the description of message.Message.use_edns() for the possible
values for use_edns and their meanings.
@type use_edns: int or bool or None
@param want_dnssec: Should the query indicate that DNSSEC is desired?
@type want_dnssec: bool
@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 request_payload: The EDNS payload size to use when sending
this message. If not specified, defaults to the value of payload.
@type request_payload: int or None
@param options: The EDNS options
@type options: None or list of edns.Option objects
@see: RFC 2671
@rtype: message.Message object"""
if isinstance(qname, (str, unicode)):
qname = mname.from_text(qname)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(rdclass, (str, unicode)):
rdclass = rdataclass.from_text(rdclass)
m = Message()
m.flags |= flags.RD
m.find_rrset(m.question,
qname,
rdclass,
rdtype,
create=True,
force_unique=True)
m.use_edns(use_edns, ednsflags, payload, request_payload, options)
m.want_dnssec(want_dnssec)
return m
def iterate_rdatasets(self, rdtype=rdatatype.ANY, covers=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 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 = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
for (name, node) in self.iteritems():
for rds in node:
if rdtype == rdatatype.ANY or \
(rds.rdtype == rdtype and rds.covers == covers):
yield (name, rds)
def _rr_line(self, section):
"""Process one line from the text format answer, authority, or
additional data sections.
"""
deleting = None
# Name
token = self.tok.get(want_leading = True)
if not token.is_whitespace():
self.last_name = mname.from_text(token.value, None)
name = self.last_name
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
# TTL
try:
ttl = int(token.value, 0)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
ttl = 0
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
if rdclass == rdataclass.ANY or rdclass == rdataclass.NONE:
deleting = rdclass
rdclass = self.zone_rdclass
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = rdataclass.IN
# Type
rdtype = rdatatype.from_text(token.value)
token = self.tok.get()
if not token.is_eol_or_eof():
self.tok.unget(token)
rd = rdata.from_text(rdclass, rdtype, self.tok, None)
covers = rd.covers()
else:
rd = None
covers = rdatatype.NONE
rrset = self.message.find_rrset(section, name,
rdclass, rdtype, covers,
deleting, True, self.updating)
if not rd is None:
rrset.add(rd, ttl)
def find_rrset(self, name, rdtype, covers=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: rrset.RRset object
"""
name = self._validate_name(name)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
rdataset = self.nodes[name].find_rdataset(self.rdclass, rdtype, covers)
rrset = rrset.RRset(name, self.rdclass, rdtype, covers)
rrset.update(rdataset)
return rrset
def iterate_rdatasets(self, rdtype=rdatatype.ANY,
covers=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 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 = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
for (name, node) in self.iteritems():
for rds in node:
if rdtype == rdatatype.ANY or \
(rds.rdtype == rdtype and rds.covers == covers):
yield (name, rds)
def find_rrset(self, name, rdtype, covers=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: rrset.RRset object
"""
name = self._validate_name(name)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(covers, (str, unicode)):
covers = rdatatype.from_text(covers)
rdataset = self.nodes[name].find_rdataset(self.rdclass, rdtype, covers)
rrset = rrset.RRset(name, self.rdclass, rdtype, covers)
rrset.update(rdataset)
return rrset
def _rr_line(self, section):
"""Process one line from the text format answer, authority, or
additional data sections.
"""
deleting = None
# Name
token = self.tok.get(want_leading=True)
if not token.is_whitespace():
self.last_name = mname.from_text(token.value, None)
name = self.last_name
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
# TTL
try:
ttl = int(token.value, 0)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
ttl = 0
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
if rdclass == rdataclass.ANY or rdclass == rdataclass.NONE:
deleting = rdclass
rdclass = self.zone_rdclass
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = rdataclass.IN
# Type
rdtype = rdatatype.from_text(token.value)
token = self.tok.get()
if not token.is_eol_or_eof():
self.tok.unget(token)
rd = rdata.from_text(rdclass, rdtype, self.tok, None)
covers = rd.covers()
else:
rd = None
covers = rdatatype.NONE
rrset = self.message.find_rrset(section, name, rdclass, rdtype, covers,
deleting, True, self.updating)
if not rd is None:
rrset.add(rd, ttl)
def make_query(qname, rdtype, rdclass = rdataclass.IN, use_edns=None,
want_dnssec=False, ednsflags=0, payload=1280,
request_payload=None, options=None):
"""Make a query message.
The query name, type, and class may all be specified either
as objects of the appropriate type, or as strings.
The query will have a randomly choosen query id, and its DNS flags
will be set to flags.RD.
@param qname: The query name.
@type qname: mname.Name object or string
@param rdtype: The desired rdata type.
@type rdtype: int
@param rdclass: The desired rdata class; the default is class IN.
@type rdclass: int
@param use_edns: The EDNS level to use; the default is None (no EDNS).
See the description of message.Message.use_edns() for the possible
values for use_edns and their meanings.
@type use_edns: int or bool or None
@param want_dnssec: Should the query indicate that DNSSEC is desired?
@type want_dnssec: bool
@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 request_payload: The EDNS payload size to use when sending
this message. If not specified, defaults to the value of payload.
@type request_payload: int or None
@param options: The EDNS options
@type options: None or list of edns.Option objects
@see: RFC 2671
@rtype: message.Message object"""
if isinstance(qname, (str, unicode)):
qname = mname.from_text(qname)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if isinstance(rdclass, (str, unicode)):
rdclass = rdataclass.from_text(rdclass)
m = Message()
m.flags |= flags.RD
m.find_rrset(m.question, qname, rdclass, rdtype, create=True,
force_unique=True)
m.use_edns(use_edns, ednsflags, payload, request_payload, options)
m.want_dnssec(want_dnssec)
return m
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
algorithm = tok.get_uint8()
flags = tok.get_uint8()
iterations = tok.get_uint16()
salt = tok.get_string()
if salt == '-':
salt = ''
else:
salt = salt.decode('hex-codec')
next = tok.get_string().upper().translate(b32_hex_to_normal)
next = base64.b32decode(next)
rdtypes = []
while 1:
token = tok.get().unescape()
if token.is_eol_or_eof():
break
nrdtype = rdatatype.from_text(token.value)
if nrdtype == 0:
raise exception.SyntaxError("NSEC3 with bit 0")
if nrdtype > 65535:
raise exception.SyntaxError("NSEC3 with bit > 65535")
rdtypes.append(nrdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = ['\0'] * 32
windows = []
for nrdtype in rdtypes:
if nrdtype == prior_rdtype:
continue
prior_rdtype = nrdtype
new_window = nrdtype // 256
if new_window != window:
if octets != 0:
windows.append((window, ''.join(bitmap[0:octets])))
bitmap = ['\0'] * 32
window = new_window
offset = nrdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = chr(ord(bitmap[byte]) | (0x80 >> bit))
if octets != 0:
windows.append((window, ''.join(bitmap[0:octets])))
return cls(rdclass, rdtype, algorithm, flags, iterations, salt, next,
windows)
def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
algorithm = tok.get_uint8()
flags = tok.get_uint8()
iterations = tok.get_uint16()
salt = tok.get_string()
if salt == '-':
salt = ''
else:
salt = salt.decode('hex-codec')
next = tok.get_string().upper().translate(b32_hex_to_normal)
next = base64.b32decode(next)
rdtypes = []
while 1:
token = tok.get().unescape()
if token.is_eol_or_eof():
break
nrdtype = rdatatype.from_text(token.value)
if nrdtype == 0:
raise exception.SyntaxError("NSEC3 with bit 0")
if nrdtype > 65535:
raise exception.SyntaxError("NSEC3 with bit > 65535")
rdtypes.append(nrdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = ['\0'] * 32
windows = []
for nrdtype in rdtypes:
if nrdtype == prior_rdtype:
continue
prior_rdtype = nrdtype
new_window = nrdtype // 256
if new_window != window:
if octets != 0:
windows.append((window, ''.join(bitmap[0:octets])))
bitmap = ['\0'] * 32
window = new_window
offset = nrdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = chr(ord(bitmap[byte]) | (0x80 >> bit))
if octets != 0:
windows.append((window, ''.join(bitmap[0:octets])))
return cls(rdclass, rdtype, algorithm, flags, iterations, salt, next, windows)
def from_text_list(rdclass, rdtype, ttl, text_rdatas):
"""Create an rdataset with the specified class, type, and TTL, and with
the specified list of rdatas in text format.
@rtype: rdataset.Rdataset object
"""
if isinstance(rdclass, (str, unicode)):
rdclass = rdataclass.from_text(rdclass)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
r = Rdataset(rdclass, rdtype)
r.update_ttl(ttl)
for t in text_rdatas:
rd = rdata.from_text(r.rdclass, r.rdtype, t)
r.add(rd)
return r
def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
type_covered = rdatatype.from_text(tok.get_string())
algorithm = dnssec.algorithm_from_text(tok.get_string())
labels = tok.get_int()
original_ttl = tok.get_ttl()
expiration = sigtime_to_posixtime(tok.get_string())
inception = sigtime_to_posixtime(tok.get_string())
key_tag = tok.get_int()
signer = tok.get_name()
signer = signer.choose_relativity(origin, relativize)
chunks = []
while 1:
t = tok.get().unescape()
if t.is_eol_or_eof():
break
if not t.is_identifier():
raise exception.SyntaxError
chunks.append(t.value)
b64 = ''.join(chunks)
signature = b64.decode('base64_codec')
return cls(rdclass, rdtype, type_covered, algorithm, labels,
original_ttl, expiration, inception, key_tag, signer,
signature)
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
next = tok.get_name()
next = next.choose_relativity(origin, relativize)
rdtypes = []
while 1:
token = tok.get().unescape()
if token.is_eol_or_eof():
break
nrdtype = rdatatype.from_text(token.value)
if nrdtype == 0:
raise exception.SyntaxError("NSEC with bit 0")
if nrdtype > 65535:
raise exception.SyntaxError("NSEC with bit > 65535")
rdtypes.append(nrdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = ["\0"] * 32
windows = []
for nrdtype in rdtypes:
if nrdtype == prior_rdtype:
continue
prior_rdtype = nrdtype
new_window = nrdtype // 256
if new_window != window:
windows.append((window, "".join(bitmap[0:octets])))
bitmap = ["\0"] * 32
window = new_window
offset = nrdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = chr(ord(bitmap[byte]) | (0x80 >> bit))
windows.append((window, "".join(bitmap[0:octets])))
return cls(rdclass, rdtype, next, windows)
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
next = tok.get_name()
next = next.choose_relativity(origin, relativize)
rdtypes = []
while 1:
token = tok.get().unescape()
if token.is_eol_or_eof():
break
nrdtype = rdatatype.from_text(token.value)
if nrdtype == 0:
raise exception.SyntaxError("NSEC with bit 0")
if nrdtype > 65535:
raise exception.SyntaxError("NSEC with bit > 65535")
rdtypes.append(nrdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = ['\0'] * 32
windows = []
for nrdtype in rdtypes:
if nrdtype == prior_rdtype:
continue
prior_rdtype = nrdtype
new_window = nrdtype // 256
if new_window != window:
windows.append((window, ''.join(bitmap[0:octets])))
bitmap = ['\0'] * 32
window = new_window
offset = nrdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = chr(ord(bitmap[byte]) | (0x80 >> bit))
windows.append((window, ''.join(bitmap[0:octets])))
return cls(rdclass, rdtype, next, windows)
def xfr(where, zone, rdtype=rdatatype.AXFR, rdclass=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=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: name.Name object or string
@param rdtype: The type of zone transfer. The default is
rdatatype.AXFR.
@type rdtype: int or string
@param rdclass: The class of the zone transfer. The default is
rdataclass.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: 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 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 message.Message objects.
@param source: source address. The default is the 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 == 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
tsig.default_algorithm
@type keyalgorithm: string
"""
if isinstance(zone, (str, unicode)):
zone = name.from_text(zone)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
q = message.make_query(zone, rdtype, rdclass)
if rdtype == rdatatype.IXFR:
rrset = 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()
(af, destination, source) = _destination_and_source(af, where, port, source,
source_port)
if use_udp:
if rdtype != 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
delete_mode = True
expecting_SOA = False
soa_rrset = None
soa_count = 0
if relativize:
origin = zone
oname = 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 = 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==rdatatype.IXFR))
tsig_ctx = r.tsig_ctx
first = False
answer_index = 0
if soa_rrset is None:
if not r.answer or r.answer[0].name != oname:
raise exception.FormError("No answer or RRset not for qname")
rrset = r.answer[0]
if rrset.rdtype != rdatatype.SOA:
raise exception.FormError("first RRset is not an SOA")
answer_index = 1
soa_rrset = rrset.copy()
if rdtype == 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 exception.FormError("answers after final SOA")
if rrset.rdtype == rdatatype.SOA and rrset.name == oname:
if expecting_SOA:
if rrset[0].serial != serial:
raise exception.FormError("IXFR base serial mismatch")
expecting_SOA = False
elif rdtype == rdatatype.IXFR:
delete_mode = not delete_mode
#
# If this SOA RRset is equal to the first we saw then we're
# finished. If this is an IXFR we also check that we're seeing
# the record in the expected part of the response.
#
if rrset == soa_rrset and \
(rdtype == rdatatype.AXFR or \
(rdtype == rdatatype.IXFR and 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 = rdatatype.AXFR
expecting_SOA = False
if done and q.keyring and not r.had_tsig:
raise exception.FormError("missing TSIG")
yield r
s.close()
def query(self, qname, rdtype=rdatatype.A, rdclass=rdataclass.IN,
tcp=False, source=None, raise_on_no_answer=True, source_port=0):
"""Query nameservers to find the answer to the question.
The I{qname}, I{rdtype}, and I{rdclass} parameters may be objects
of the appropriate type, or strings that can be converted into objects
of the appropriate type. E.g. For I{rdtype} the integer 2 and the
the string 'NS' both mean to query for records with DNS rdata type NS.
@param qname: the query name
@type qname: name.Name object or string
@param rdtype: the query type
@type rdtype: int or string
@param rdclass: the query class
@type rdclass: int or string
@param tcp: use TCP to make the query (default is False).
@type tcp: bool
@param source: bind to this IP address (defaults to machine default IP).
@type source: IP address in dotted quad notation
@param raise_on_no_answer: raise NoAnswer if there's no answer
(defaults is True).
@type raise_on_no_answer: bool
@param source_port: The port from which to send the message.
The default is 0.
@type source_port: int
@rtype: resolver.Answer instance
@raises Timeout: no answers could be found in the specified lifetime
@raises NXDOMAIN: the query name does not exist
@raises YXDOMAIN: the query name is too long after DNAME substitution
@raises NoAnswer: the response did not contain an answer and
raise_on_no_answer is True.
@raises NoNameservers: no non-broken nameservers are available to
answer the question."""
#import pdb
#pdb.set_trace()
if isinstance(qname, (str, unicode)):
qname = name.from_text(qname, None)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
if rdatatype.is_metatype(rdtype):
raise NoMetaqueries
if isinstance(rdclass, (str, unicode)):
rdclass = rdataclass.from_text(rdclass)
if rdataclass.is_metaclass(rdclass):
raise NoMetaqueries
qnames_to_try = []
if qname.is_absolute():
qnames_to_try.append(qname)
else:
if len(qname) > 1:
qnames_to_try.append(qname.concatenate(name.root))
if self.search:
for suffix in self.search:
qnames_to_try.append(qname.concatenate(suffix))
else:
qnames_to_try.append(qname.concatenate(self.domain))
all_nxdomain = True
start = time.time()
for qname in qnames_to_try:
if self.cache:
answer = self.cache.get((qname, rdtype, rdclass))
if not answer is None:
if answer.rrset is None and raise_on_no_answer:
raise NoAnswer
else:
return answer
request = message.make_query(qname, rdtype, rdclass)
if not self.keyname is None:
request.use_tsig(self.keyring, self.keyname,
algorithm=self.keyalgorithm)
request.use_edns(self.edns, self.ednsflags, self.payload)
if self.flags is not None:
request.flags = self.flags
response = None
#
# make a copy of the servers list so we can alter it later.
#
nameservers = self.nameservers[:]
if self.rotate:
random.shuffle(nameservers)
backoff = 0.10
while response is None:
if len(nameservers) == 0:
raise NoNameservers
for nameserver in nameservers[:]:
timeout = self._compute_timeout(start)
try:
if tcp:
response = mquery.tcp(request, nameserver,
timeout, self.port,
source=source,
source_port=source_port)
else:
response = mquery.udp(request, nameserver,
timeout, self.port,
source=source,
source_port=source_port)
if response.flags & flags.TC:
# Response truncated; retry with TCP.
timeout = self._compute_timeout(start)
response = mquery.tcp(request, nameserver,
timeout, self.port,
source=source,
source_port=source_port)
except (socket.error, exception.Timeout):
#
# Communication failure or timeout. Go to the
# next server
#
response = None
continue
except mquery.UnexpectedSource:
#
# Who knows? Keep going.
#
response = None
continue
except exception.FormError:
#
# We don't understand what this server is
# saying. Take it out of the mix and
# continue.
#
nameservers.remove(nameserver)
response = None
continue
except EOFError:
#
# We're using TCP and they hung up on us.
# Probably they don't support TCP (though
# they're supposed to!). Take it out of the
# mix and continue.
#
nameservers.remove(nameserver)
response = None
continue
rcode = response.rcode()
if rcode == mrcode.YXDOMAIN:
raise YXDOMAIN
if rcode == mrcode.NOERROR or \
rcode == mrcode.NXDOMAIN:
break
#
# We got a response, but we're not happy with the
# rcode in it. Remove the server from the mix if
# the rcode isn't SERVFAIL.
#
if rcode != mrcode.SERVFAIL or not self.retry_servfail:
nameservers.remove(nameserver)
response = None
if not response is None:
break
#
# All nameservers failed!
#
if len(nameservers) > 0:
#
# But we still have servers to try. Sleep a bit
# so we don't pound them!
#
timeout = self._compute_timeout(start)
sleep_time = min(timeout, backoff)
backoff *= 2
time.sleep(sleep_time)
if response.rcode() == mrcode.NXDOMAIN:
continue
all_nxdomain = False
break
if all_nxdomain:
raise NXDOMAIN
answer = Answer(qname, rdtype, rdclass, response,
raise_on_no_answer)
if self.cache:
self.cache.put((qname, rdtype, rdclass), answer)
return answer
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 = 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 exception.SyntaxError
# TTL
try:
ttl = ttl.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except ttl.BadTTL:
ttl = self.ttl
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = self.zone.rdclass
if rdclass != self.zone.rdclass:
raise exception.SyntaxError("RR class is not zone's class")
# Type
try:
rdtype = rdatatype.from_text(token.value)
except:
raise 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 = rdata.from_text(rdclass, rdtype, self.tok,
self.current_origin, False)
except 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 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 _generate_line(self):
# range lhs [ttl] [class] type rhs [ comment ]
"""Process one line containing the GENERATE statement from a DNS
master file."""
if self.current_origin is None:
raise UnknownOrigin
token = self.tok.get()
# Range (required)
try:
start, stop, step = grange.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError
# lhs (required)
try:
lhs = token.value
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError
# TTL
try:
ttl = ttl.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except ttl.BadTTL:
ttl = self.ttl
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = self.zone.rdclass
if rdclass != self.zone.rdclass:
raise exception.SyntaxError("RR class is not zone's class")
# Type
try:
rdtype = rdatatype.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError("unknown rdatatype '%s'" %
token.value)
# lhs (required)
try:
rhs = token.value
except:
raise exception.SyntaxError
lmod, lsign, loffset, lwidth, lbase = self._parse_modify(lhs)
rmod, rsign, roffset, rwidth, rbase = self._parse_modify(rhs)
for i in range(start, stop + 1, step):
# +1 because bind is inclusive and python is exclusive
if lsign == '+':
lindex = i + int(loffset)
elif lsign == '-':
lindex = i - int(loffset)
if rsign == '-':
rindex = i - int(roffset)
elif rsign == '+':
rindex = i + int(roffset)
lzfindex = str(lindex).zfill(int(lwidth))
rzfindex = str(rindex).zfill(int(rwidth))
name = lhs.replace('$%s' % (lmod), lzfindex)
rdata = rhs.replace('$%s' % (rmod), rzfindex)
self.last_name = name.from_text(name, self.current_origin)
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)
n = self.zone.nodes.get(name)
if n is None:
n = self.zone.node_factory()
self.zone.nodes[name] = n
try:
rd = rdata.from_text(rdclass, rdtype, rdata,
self.current_origin, False)
except 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 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 _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 = 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 exception.SyntaxError
# TTL
try:
ttl = ttl.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except ttl.BadTTL:
ttl = self.ttl
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = self.zone.rdclass
if rdclass != self.zone.rdclass:
raise exception.SyntaxError("RR class is not zone's class")
# Type
try:
rdtype = rdatatype.from_text(token.value)
except:
raise 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 = rdata.from_text(rdclass, rdtype, self.tok,
self.current_origin, False)
except 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 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 xfr(where,
zone,
rdtype=rdatatype.AXFR,
rdclass=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=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: name.Name object or string
@param rdtype: The type of zone transfer. The default is
rdatatype.AXFR.
@type rdtype: int or string
@param rdclass: The class of the zone transfer. The default is
rdataclass.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: 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 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 message.Message objects.
@param source: source address. The default is the 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 == 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
tsig.default_algorithm
@type keyalgorithm: string
"""
if isinstance(zone, (str, unicode)):
zone = name.from_text(zone)
if isinstance(rdtype, (str, unicode)):
rdtype = rdatatype.from_text(rdtype)
q = message.make_query(zone, rdtype, rdclass)
if rdtype == rdatatype.IXFR:
rrset = 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()
(af, destination,
source) = _destination_and_source(af, where, port, source, source_port)
if use_udp:
if rdtype != 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
delete_mode = True
expecting_SOA = False
soa_rrset = None
soa_count = 0
if relativize:
origin = zone
oname = 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 = 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 == rdatatype.IXFR))
tsig_ctx = r.tsig_ctx
first = False
answer_index = 0
if soa_rrset is None:
if not r.answer or r.answer[0].name != oname:
raise exception.FormError("No answer or RRset not for qname")
rrset = r.answer[0]
if rrset.rdtype != rdatatype.SOA:
raise exception.FormError("first RRset is not an SOA")
answer_index = 1
soa_rrset = rrset.copy()
if rdtype == 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 exception.FormError("answers after final SOA")
if rrset.rdtype == rdatatype.SOA and rrset.name == oname:
if expecting_SOA:
if rrset[0].serial != serial:
raise exception.FormError("IXFR base serial mismatch")
expecting_SOA = False
elif rdtype == rdatatype.IXFR:
delete_mode = not delete_mode
#
# If this SOA RRset is equal to the first we saw then we're
# finished. If this is an IXFR we also check that we're seeing
# the record in the expected part of the response.
#
if rrset == soa_rrset and \
(rdtype == rdatatype.AXFR or \
(rdtype == rdatatype.IXFR and 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 = rdatatype.AXFR
expecting_SOA = False
if done and q.keyring and not r.had_tsig:
raise exception.FormError("missing TSIG")
yield r
s.close()
def _generate_line(self):
# range lhs [ttl] [class] type rhs [ comment ]
"""Process one line containing the GENERATE statement from a DNS
master file."""
if self.current_origin is None:
raise UnknownOrigin
token = self.tok.get()
# Range (required)
try:
start, stop, step = grange.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError
# lhs (required)
try:
lhs = token.value
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError
# TTL
try:
ttl = ttl.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except ttl.BadTTL:
ttl = self.ttl
# Class
try:
rdclass = rdataclass.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except exception.SyntaxError:
raise exception.SyntaxError
except:
rdclass = self.zone.rdclass
if rdclass != self.zone.rdclass:
raise exception.SyntaxError("RR class is not zone's class")
# Type
try:
rdtype = rdatatype.from_text(token.value)
token = self.tok.get()
if not token.is_identifier():
raise exception.SyntaxError
except:
raise exception.SyntaxError("unknown rdatatype '%s'" % token.value)
# lhs (required)
try:
rhs = token.value
except:
raise exception.SyntaxError
lmod, lsign, loffset, lwidth, lbase = self._parse_modify(lhs)
rmod, rsign, roffset, rwidth, rbase = self._parse_modify(rhs)
for i in range(start, stop + 1, step):
# +1 because bind is inclusive and python is exclusive
if lsign == '+':
lindex = i + int(loffset)
elif lsign == '-':
lindex = i - int(loffset)
if rsign == '-':
rindex = i - int(roffset)
elif rsign == '+':
rindex = i + int(roffset)
lzfindex = str(lindex).zfill(int(lwidth))
rzfindex = str(rindex).zfill(int(rwidth))
name = lhs.replace('$%s' % (lmod), lzfindex)
rdata = rhs.replace('$%s' % (rmod), rzfindex)
self.last_name = name.from_text(name, self.current_origin)
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)
n = self.zone.nodes.get(name)
if n is None:
n = self.zone.node_factory()
self.zone.nodes[name] = n
try:
rd = rdata.from_text(rdclass, rdtype, rdata,
self.current_origin, False)
except 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 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)
