self.origin = None
self.tsig_ctx = None
self.index = {}
+ self.errors = []
@property
def question(self):
def __init__(self, wire, initialize_message, question_only=False,
one_rr_per_rrset=False, ignore_trailing=False,
- keyring=None, multi=False):
+ keyring=None, multi=False, continue_on_error=False):
self.parser = dns.wire.Parser(wire)
self.message = None
self.initialize_message = initialize_message
self.ignore_trailing = ignore_trailing
self.keyring = keyring
self.multi = multi
+ self.continue_on_error = continue_on_error
+ self.last_good = 0
+ self.errors = []
def _get_question(self, section_number, qcount):
"""Read the next *qcount* records from the wire data and add them to
rdtype)
self.message.find_rrset(section, qname, rdclass, rdtype,
create=True, force_unique=True)
+ self.last_good = self.parser.current
def _get_section(self, section_number, count):
"""Read the next I{count} records from the wire data and add them to
the specified section.
- section: the section of the message to which to add records
+ section_number: the section of the message to which to add records
count: the number of records to read
"""
(rdclass, rdtype, deleting, empty) = \
self.message._parse_rr_header(section_number,
name, rdclass, rdtype)
- if empty:
- if rdlen > 0:
- raise dns.exception.FormError
- rd = None
- covers = dns.rdatatype.NONE
- else:
- with self.parser.restrict_to(rdlen):
- rd = dns.rdata.from_wire_parser(rdclass, rdtype,
- self.parser,
- self.message.origin)
- covers = rd.covers()
- if self.message.xfr and rdtype == dns.rdatatype.SOA:
- force_unique = True
- if rdtype == dns.rdatatype.OPT:
- self.message.opt = dns.rrset.from_rdata(name, ttl, rd)
- elif rdtype == dns.rdatatype.TSIG:
- if self.keyring is None:
- raise UnknownTSIGKey('got signed message without keyring')
- if isinstance(self.keyring, dict):
- key = self.keyring.get(absolute_name)
- if isinstance(key, bytes):
- key = dns.tsig.Key(absolute_name, key, rd.algorithm)
- elif callable(self.keyring):
- key = self.keyring(self.message, absolute_name)
+ try:
+ if empty:
+ if rdlen > 0:
+ raise dns.exception.FormError
+ rd = None
+ covers = dns.rdatatype.NONE
else:
- key = self.keyring
- if key is None:
- raise UnknownTSIGKey("key '%s' unknown" % name)
- self.message.keyring = key
- self.message.tsig_ctx = \
- dns.tsig.validate(self.parser.wire,
- key,
- absolute_name,
- rd,
- int(time.time()),
- self.message.request_mac,
- rr_start,
- self.message.tsig_ctx,
- self.multi)
- self.message.tsig = dns.rrset.from_rdata(absolute_name, 0, rd)
- else:
- rrset = self.message.find_rrset(section, name,
- rdclass, rdtype, covers,
- deleting, True,
- force_unique)
- if rd is not None:
- if ttl > 0x7fffffff:
- ttl = 0
- rrset.add(rd, ttl)
+ self.last_good = self.parser.current
+ with self.parser.restrict_to(rdlen):
+ rd = dns.rdata.from_wire_parser(rdclass, rdtype,
+ self.parser,
+ self.message.origin)
+ covers = rd.covers()
+ if self.message.xfr and rdtype == dns.rdatatype.SOA:
+ force_unique = True
+ if rdtype == dns.rdatatype.OPT:
+ self.message.opt = dns.rrset.from_rdata(name, ttl, rd)
+ elif rdtype == dns.rdatatype.TSIG:
+ if self.keyring is None:
+ raise UnknownTSIGKey('got signed message without '
+ 'keyring')
+ if isinstance(self.keyring, dict):
+ key = self.keyring.get(absolute_name)
+ if isinstance(key, bytes):
+ key = dns.tsig.Key(absolute_name, key, rd.algorithm)
+ elif callable(self.keyring):
+ key = self.keyring(self.message, absolute_name)
+ else:
+ key = self.keyring
+ if key is None:
+ raise UnknownTSIGKey("key '%s' unknown" % name)
+ self.message.keyring = key
+ self.message.tsig_ctx = \
+ dns.tsig.validate(self.parser.wire,
+ key,
+ absolute_name,
+ rd,
+ int(time.time()),
+ self.message.request_mac,
+ rr_start,
+ self.message.tsig_ctx,
+ self.multi)
+ self.message.tsig = dns.rrset.from_rdata(absolute_name, 0,
+ rd)
+ else:
+ rrset = self.message.find_rrset(section, name,
+ rdclass, rdtype, covers,
+ deleting, True,
+ force_unique)
+ if rd is not None:
+ if ttl > 0x7fffffff:
+ ttl = 0
+ rrset.add(rd, ttl)
+ except Exception as e:
+ if self.continue_on_error:
+ self.errors.append((self.last_good, str(e), e))
+ try:
+ self.parser.seek(self.last_good + rdlen)
+ except dns.exception.FormError:
+ # seek was past the end
+ self.parser.seek(self.parser.end)
+ if i != count - 1:
+ senum = MessageSection(section_number)
+ self.errors.append((self.end, 'not enough RRs in '
+ f'section {senum}',
+ None))
+ return
+ else:
+ raise
def read(self):
"""Read a wire format DNS message and build a dns.message.Message
self.initialize_message(self.message)
self.one_rr_per_rrset = \
self.message._get_one_rr_per_rrset(self.one_rr_per_rrset)
- self._get_question(MessageSection.QUESTION, qcount)
- if self.question_only:
- return self.message
- self._get_section(MessageSection.ANSWER, ancount)
- self._get_section(MessageSection.AUTHORITY, aucount)
- self._get_section(MessageSection.ADDITIONAL, adcount)
- if not self.ignore_trailing and self.parser.remaining() != 0:
- raise TrailingJunk
- if self.multi and self.message.tsig_ctx and not self.message.had_tsig:
- self.message.tsig_ctx.update(self.parser.wire)
+ try:
+ self._get_question(MessageSection.QUESTION, qcount)
+ if self.question_only:
+ return self.message
+ self._get_section(MessageSection.ANSWER, ancount)
+ self._get_section(MessageSection.AUTHORITY, aucount)
+ self._get_section(MessageSection.ADDITIONAL, adcount)
+ if not self.ignore_trailing and self.parser.remaining() != 0:
+ raise TrailingJunk
+ if self.multi and self.message.tsig_ctx and \
+ not self.message.had_tsig:
+ self.message.tsig_ctx.update(self.parser.wire)
+ except Exception as e:
+ if self.continue_on_error:
+ self.errors.append((self.last_good, str(e), e))
+ else:
+ raise
return self.message
def from_wire(wire, keyring=None, request_mac=b'', xfr=False, origin=None,
tsig_ctx=None, multi=False,
question_only=False, one_rr_per_rrset=False,
- ignore_trailing=False, raise_on_truncation=False):
+ ignore_trailing=False, raise_on_truncation=False,
+ continue_on_error=False):
"""Convert a DNS wire format message into a message
object.
*raise_on_truncation*, a ``bool``. If ``True``, raise an exception if
the TC bit is set.
+
+ *continue_on_error*, a ``bool``. If ``True``, try to continue parsing
+ even if errors occur. Erroneous rdata will be ignored, but records
+ of the errors will be added to the message ``errors`` field. This option
+ is recommended only for DNS debugging. The default is ``False``.
Raises ``dns.message.ShortHeader`` if the message is less than 12 octets
long.
message.tsig_ctx = tsig_ctx
reader = _WireReader(wire, initialize_message, question_only,
- one_rr_per_rrset, ignore_trailing, keyring, multi)
+ one_rr_per_rrset, ignore_trailing, keyring, multi,
+ continue_on_error)
try:
m = reader.read()
except dns.exception.FormError:
# have to do this check here too.
if m.flags & dns.flags.TC and raise_on_truncation:
raise Truncated(message=m)
+ if continue_on_error:
+ m.errors = reader.errors
return m
projects / thirdparty / dnspython.git / commitdiff
