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update ns

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This commit is contained in:
clowwindy 2014-06-07 11:50:30 +08:00
parent 795e0f4b8e
commit 7a77205530
1 changed files with 156 additions and 19 deletions
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155
shadowsocks/asyncdns.py
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@ -29,6 +29,20 @@ import common
_request_count = 1 _request_count = 1
# rfc1035 # rfc1035
# format
# +---------------------+
# | Header |
# +---------------------+
# | Question | the question for the name server
# +---------------------+
# | Answer | RRs answering the question
# +---------------------+
# | Authority | RRs pointing toward an authority
# +---------------------+
# | Additional | RRs holding additional information
# +---------------------+
#
# header
# 1 1 1 1 1 1 # 1 1 1 1 1 1
# 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 # 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ # +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@ -48,10 +62,22 @@ _request_count = 1
QTYPE_ANY = 255 QTYPE_ANY = 255
QTYPE_A = 1 QTYPE_A = 1
QTYPE_AAAA = 28 QTYPE_AAAA = 28
QTYPE_CNAME = 5
QCLASS_IN = 1 QCLASS_IN = 1
def convert_address(address): def parse_ip(addrtype, data, length, offset):
if addrtype == QTYPE_A:
return socket.inet_ntop(socket.AF_INET, data[offset:offset + length])
elif addrtype == QTYPE_AAAA:
return socket.inet_ntop(socket.AF_INET6, data[offset:offset + length])
elif addrtype == QTYPE_CNAME:
return parse_name(data, offset, length)[1]
else:
return data
def pack_address(address):
address = address.strip('.') address = address.strip('.')
labels = address.split('.') labels = address.split('.')
results = [] results = []
@ -68,32 +94,137 @@ def convert_address(address):
def pack_request(address): def pack_request(address):
global _request_count global _request_count
header = struct.pack('!HBBHHHH', _request_count, 1, 0, 1, 0, 0, 0) header = struct.pack('!HBBHHHH', _request_count, 1, 0, 1, 0, 0, 0)
addr = convert_address(address) addr = pack_address(address)
qtype_qclass = struct.pack('!HH', QTYPE_A, QCLASS_IN) qtype_qclass = struct.pack('!HH', QTYPE_ANY, QCLASS_IN)
_request_count += 1 _request_count += 1
if _request_count > 65535:
_request_count = 1
return header + addr + qtype_qclass return header + addr + qtype_qclass
def parse_name(data, offset, length=512):
p = offset
if (ord(data[offset]) & (128 + 64)) == (128 + 64):
# pointer
pointer = struct.unpack('!H', data[offset:offset + 2])[0]
pointer = pointer & 0x3FFF
if pointer == offset:
return (0, None)
return (2, parse_name(data, pointer))
else:
labels = []
l = ord(data[p])
while l > 0 and p < offset + length:
if (l & (128 + 64)) == (128 + 64):
# pointer
pointer = struct.unpack('!H', data[p:p + 2])[0]
pointer = pointer & 0x3FFF
# if pointer == offset:
# return (0, None)
r = parse_name(data, pointer)
labels.append(r[1])
p += 2
# pointer is the end
return (p - offset + 1, '.'.join(labels))
else:
labels.append(data[p + 1:p + 1 + l])
p += 1 + l
l = ord(data[p])
return (p - offset + 1, '.'.join(labels))
# rfc1035
# record
# 1 1 1 1 1 1
# 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
# | |
# / /
# / NAME /
# | |
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
# | TYPE |
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
# | CLASS |
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
# | TTL |
# | |
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
# | RDLENGTH |
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
# / RDATA /
# / /
# +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
def parse_record(data, offset, question=False):
len, name = parse_name(data, offset)
# TODO
assert len
if not question:
record_type, record_class, record_ttl, record_rdlength = struct.unpack(
'!HHiH', data[offset + len:offset + len + 10]
)
ip = parse_ip(record_type, data, record_rdlength, offset + len + 10)
return len + 10 + record_rdlength, \
(name, ip, record_type, record_class, record_ttl)
else:
record_type, record_class = struct.unpack(
'!HH', data[offset + len:offset + len + 4]
)
return len + 4, (name, None, record_type, record_class, None, None)
def unpack_response(data): def unpack_response(data):
if len(data) > 12: try:
if len(data) >= 12:
header = struct.unpack('!HBBHHHH', data[:12]) header = struct.unpack('!HBBHHHH', data[:12])
res_id = header[0] res_id = header[0]
res_qr = header[1] & 128 res_qr = header[1] & 128
res_tc = header[1] & 2 res_tc = header[1] & 2
res_ra = header[2] & 128 res_ra = header[2] & 128
res_rcode = header[2] & 15 res_rcode = header[2] & 15
# TODO check tc and rcode
assert res_tc == 0
assert res_rcode == 0
res_qdcount = header[3] res_qdcount = header[3]
res_ancount = header[4] res_ancount = header[4]
res_nscount = header[5] res_nscount = header[5]
res_arcount = header[6] res_arcount = header[6]
print header qds = []
# TODO detect address type ans = []
print data nss = []
print data.encode('hex') ars = []
return data offset = 12
for i in xrange(0, res_qdcount):
l, r = parse_record(data, offset, True)
offset += l
if r:
qds.append(r)
for i in xrange(0, res_ancount):
l, r = parse_record(data, offset)
offset += l
if r:
ans.append(r)
for i in xrange(0, res_nscount):
l, r = parse_record(data, offset)
offset += l
if r:
nss.append(r)
for i in xrange(0, res_arcount):
l, r = parse_record(data, offset)
offset += l
if r:
ars.append(r)
return ans
except Exception as e:
import traceback
traceback.print_exc()
return None
def resolve(address, callback): def resolve(address, callback):
# TODO async
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.SOL_UDP) sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.SOL_UDP)
req = pack_request(address) req = pack_request(address)
if req is None: if req is None:
@ -109,7 +240,13 @@ def test():
def _callback(address): def _callback(address):
print address print address
resolve('www.twitter.com', _callback)
resolve('www.google.com', _callback) resolve('www.google.com', _callback)
resolve('ipv6.google.com', _callback)
resolve('ipv6.l.google.com', _callback)
resolve('www.baidu.com', _callback)
resolve('www.a.shifen.com', _callback)
resolve('m.baidu.jp', _callback)
if __name__ == '__main__': if __name__ == '__main__':