more work
This commit is contained in:
clowwindy
parent
6b76319495
commit
45f9998fa9
2 changed files with 39 additions and 51 deletions
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@ -28,6 +28,8 @@ import common
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import eventloop
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common.patch_socket()
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_request_count = 1
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# rfc1035
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@ -99,40 +101,30 @@ def parse_ip(addrtype, data, length, offset):
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elif addrtype == QTYPE_AAAA:
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return socket.inet_ntop(socket.AF_INET6, data[offset:offset + length])
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elif addrtype == QTYPE_CNAME:
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return parse_name(data, offset, length)[1]
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return parse_name(data, offset)[1]
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else:
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return data
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def parse_name(data, offset, length=512):
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def parse_name(data, offset):
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p = offset
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if (ord(data[offset]) & (128 + 64)) == (128 + 64):
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# pointer
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pointer = struct.unpack('!H', data[offset:offset + 2])[0]
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pointer = pointer & 0x3FFF
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if pointer == offset:
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return (0, None)
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return (2, parse_name(data, pointer)[1])
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else:
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labels = []
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labels = []
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l = ord(data[p])
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while l > 0:
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if (l & (128 + 64)) == (128 + 64):
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# pointer
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pointer = struct.unpack('!H', data[p:p + 2])[0]
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pointer &= 0x3FFF
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r = parse_name(data, pointer)
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labels.append(r[1])
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p += 2
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# pointer is the end
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return p - offset, '.'.join(labels)
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else:
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labels.append(data[p + 1:p + 1 + l])
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p += 1 + l
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l = ord(data[p])
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while l > 0 and p < offset + length:
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if (l & (128 + 64)) == (128 + 64):
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# pointer
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pointer = struct.unpack('!H', data[p:p + 2])[0]
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pointer = pointer & 0x3FFF
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# if pointer == offset:
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# return (0, None)
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r = parse_name(data, pointer)
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labels.append(r[1])
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p += 2
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# pointer is the end
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return (p - offset + 1, '.'.join(labels))
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else:
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labels.append(data[p + 1:p + 1 + l])
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p += 1 + l
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l = ord(data[p])
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return (p - offset + 1, '.'.join(labels))
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return p - offset + 1, '.'.join(labels)
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# rfc1035
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@ -158,33 +150,30 @@ def parse_name(data, offset, length=512):
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# / /
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# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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def parse_record(data, offset, question=False):
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len, name = parse_name(data, offset)
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# TODO
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assert len
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nlen, name = parse_name(data, offset)
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if not question:
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record_type, record_class, record_ttl, record_rdlength = struct.unpack(
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'!HHiH', data[offset + len:offset + len + 10]
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'!HHiH', data[offset + nlen:offset + nlen + 10]
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)
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ip = parse_ip(record_type, data, record_rdlength, offset + len + 10)
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return len + 10 + record_rdlength, \
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ip = parse_ip(record_type, data, record_rdlength, offset + nlen + 10)
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return nlen + 10 + record_rdlength, \
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(name, ip, record_type, record_class, record_ttl)
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else:
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record_type, record_class = struct.unpack(
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'!HH', data[offset + len:offset + len + 4]
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'!HH', data[offset + nlen:offset + nlen + 4]
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)
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return len + 4, (name, None, record_type, record_class, None, None)
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return nlen + 4, (name, None, record_type, record_class, None, None)
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def parse_response(data):
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try:
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if len(data) >= 12:
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header = struct.unpack('!HBBHHHH', data[:12])
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res_id = header[0]
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res_qr = header[1] & 128
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# res_id = header[0]
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# res_qr = header[1] & 128
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res_tc = header[1] & 2
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res_ra = header[2] & 128
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# res_ra = header[2] & 128
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res_rcode = header[2] & 15
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# TODO check tc and rcode
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assert res_tc == 0
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assert res_rcode == 0
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res_qdcount = header[3]
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@ -193,8 +182,6 @@ def parse_response(data):
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res_arcount = header[6]
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qds = []
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ans = []
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nss = []
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ars = []
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offset = 12
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for i in xrange(0, res_qdcount):
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l, r = parse_record(data, offset, True)
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@ -209,13 +196,9 @@ def parse_response(data):
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for i in xrange(0, res_nscount):
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l, r = parse_record(data, offset)
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offset += l
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if r:
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nss.append(r)
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for i in xrange(0, res_arcount):
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l, r = parse_record(data, offset)
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offset += l
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if r:
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ars.append(r)
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response = DNSResponse()
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if qds:
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response.hostname = qds[0][0]
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@ -225,6 +208,7 @@ def parse_response(data):
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except Exception as e:
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import traceback
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traceback.print_exc()
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logging.error(e)
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return None
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@ -380,9 +364,9 @@ def test():
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resolver = DNSResolver()
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resolver.add_to_loop(loop)
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resolver.resolve('www.google.com', _callback)
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resolver.resolve('8.8.8.8', _callback)
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resolver.resolve('www.twitter.com', _callback)
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resolver.resolve('www.google.com', _callback)
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resolver.resolve('ipv6.google.com', _callback)
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resolver.resolve('ipv6.l.google.com', _callback)
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resolver.resolve('www.gmail.com', _callback)
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@ -63,11 +63,15 @@ def inet_pton(family, addr):
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raise RuntimeError("What family?")
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if not hasattr(socket, 'inet_pton'):
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socket.inet_pton = inet_pton
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def patch_socket():
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if not hasattr(socket, 'inet_pton'):
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socket.inet_pton = inet_pton
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if not hasattr(socket, 'inet_ntop'):
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socket.inet_ntop = inet_ntop
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if not hasattr(socket, 'inet_ntop'):
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socket.inet_ntop = inet_ntop
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patch_socket()
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ADDRTYPE_IPV4 = 1
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