def pack_hdr(self):
"""Return packed header string."""
try:
return _st_pack(self.__hdr_fmt__,
*[ getattr(self, k) for k in self.__hdr_fields__ ])
except _st_error:
vals = []
for k in self.__hdr_fields__:
v = getattr(self, k)
if isinstance(v, tuple):
vals.extend(v)
else:
vals.append(v)
return _st_pack(self.__hdr_fmt__, *vals)
def pack_hdr(self):
"""Return packed header string."""
try:
return _st_pack(self.__hdr_fmt__,
*[getattr(self, k) for k in self.__hdr_fields__])
except _st_error:
vals = []
for k in self.__hdr_fields__:
v = getattr(self, k)
if isinstance(v, tuple):
vals.extend(v)
else:
vals.append(v)
return _st_pack(self.__hdr_fmt__, *vals)
def encode_name(name):
"""Return the NetBIOS first-level encoded name."""
l = []
for c in _st_pack('16s', name):
c = ord(c)
l.append(chr((c >> 4) + 0x41))
l.append(chr((c & 0xf) + 0x41))
return ''.join(l)
def __str__(self):
# XXX - compress names on the fly
self.index = {}
buf = _st_pack(self.__hdr_fmt__, self.id, self.op,
len(self.qd), len(self.an), len(self.ns), len(self.ar))
for q in self.qd:
buf = self.pack_q(buf, q)
for x in ('an', 'ns', 'ar'):
for rr in getattr(self, x):
buf = self.pack_rr(buf, rr)
del self.index
return buf
def __str__(self):
# XXX - compress names on the fly
self.index = {}
buf = _st_pack(self.__hdr_fmt__, self.id, self.op, len(self.qd),
len(self.an), len(self.ns), len(self.ar))
for q in self.qd:
buf = self.pack_q(buf, q)
for x in ('an', 'ns', 'ar'):
for rr in getattr(self, x):
buf = self.pack_rr(buf, rr)
del self.index
return buf
def pack_name(self, buf, name):
"""Append compressed DNS name and return buf."""
labels = name.split('.')
labels.append('')
for i, label in enumerate(labels):
key = '.'.join(labels[i:]).upper()
ptr = self.index.get(key, None)
if not ptr:
if len(key) > 1:
ptr = len(buf)
if ptr < 0xc000:
self.index[key] = ptr
i = len(label)
buf += chr(i) + label
else:
buf += _st_pack('>H', (0xc000 | ptr))
break
return buf
def pack_name(self, buf, name):
"""Append compressed DNS name and return buf."""
labels = name.split('.')
labels.append('')
for i, label in enumerate(labels):
key = '.'.join(labels[i:]).upper()
ptr = self.index.get(key, None)
if not ptr:
if len(key) > 1:
ptr = len(buf)
if ptr < 0xc000:
self.index[key] = ptr
i = len(label)
buf += chr(i) + label
else:
buf += _st_pack('>H', (0xc000 | ptr))
break
return buf
def pack_rr(self, buf, rr):
"""Append packed DNS RR and return buf."""
buf = self.pack_name(buf, rr.name)
buf += _st_pack('>HHIH', rr.type, rr.cls, rr.ttl, len(rr.rdata))
buf += rr.rdata
return buf
def pack_q(self, buf, q):
"""Append packed DNS question and return buf."""
buf = self.pack_name(buf, q.name)
buf += _st_pack('>HH', q.type, q.cls)
return buf
def pack_rr(self, buf, rr):
"""Append packed DNS RR and return buf."""
buf = self.pack_name(buf, rr.name)
buf += _st_pack('>HHIH', rr.type, rr.cls, rr.ttl, len(rr.rdata))
buf += rr.rdata
return buf
def pack_q(self, buf, q):
"""Append packed DNS question and return buf."""
buf = self.pack_name(buf, q.name)
buf += _st_pack('>HH', q.type, q.cls)
return buf
