async def request_remote(self, nameservers, req):
last_err = None
for addr in nameservers.iter():
try:
inter_res = await self.request_once(req, addr)
logger.debug('[request_remote] %s', inter_res)
if inter_res.qd[0].name != req.qd[0].name:
raise DNSError(-1, 'Question section mismatch')
assert inter_res.r != 2, 'Remote server fail'
except Exception as e:
error_type = 'error'
if isinstance(e, (asyncio.TimeoutError, AssertionError)):
error_type = 'server_error'
elif isinstance(e, DNSError):
error_type = 'dns_error'
else:
error_type = 'error'
import traceback
traceback.print_exc()
logger.debug('[request_remote][%s] %s %s', error_type,
str(addr), repr(e))
last_err = e
else:
nameservers.success(addr)
return inter_res
nameservers.fail(addr)
else:
raise last_err
async def query_remote_once(self, domain, nameservers=None):
resolver = self.resolver
req = DNSMessage(qr=REQUEST)
if nameservers is None:
nameservers = resolver.get_nameservers(domain)
req.qd = [Record(REQUEST, domain, self.qtype)]
logger.debug('[query_remote_once][%s][%s] %s', types.get_name(self.qtype), domain, nameservers)
inter_res = await self.request_remote(nameservers, req)
resolver.cache_message(inter_res)
return inter_res
async def query(self):
domain = self.fqdn
nameservers = None
while True:
self._cached = await self.query_cache(domain)
logger.debug('[query_cache][%s][%s] %s',
types.get_name(self.qtype), domain, self._cached)
if self._cached: break
remote_res = await self.query_remote(domain, nameservers)
logger.debug('[query_remote][%s][%s] %s',
types.get_name(self.qtype), domain, remote_res)
if remote_res is None: break
domain, nameservers = remote_res
return self._result, self._cached
async def query(self):
error = None
domain = self.fqdn
nameservers = None
try:
while True:
if not self.future.cancelled():
self.from_cache = await self.query_cache(domain)
logger.debug('[query_cache][%s][%s] %s', types.get_name(self.qtype), domain, self.from_cache)
if self.from_cache: break
if not self.future.cancelled():
remote_res = await self.query_remote(domain, nameservers)
logger.debug('[query_remote][%s][%s] %s', types.get_name(self.qtype), domain, remote_res)
if remote_res is None: break
domain, nameservers = remote_res
except Exception as e:
error = e
if not self.future.cancelled():
if error:
self.future.set_exception(error)
else:
self.future.set_result((self._result, self.from_cache))
async def request_remote(self, nameservers, req):
while not self.future.cancelled():
addr = nameservers.get()
if not addr:
raise InvalidNameServer
try:
data = await self.request_once(req, addr)
inter_res = DNSMessage.parse(data)
logger.debug('[request_remote] %s', inter_res)
if inter_res.qd[0].name != req.qd[0].name:
raise DNSError(-1, 'Question section mismatch')
assert inter_res.r != 2, 'Remote server fail'
except (asyncio.TimeoutError, AssertionError) as e:
logger.debug('[request_remote][server_error] %s', e)
except DNSError as e:
logger.debug('[request_remote][dns_error] %s', e)
except Exception as e:
logger.error('[request_remote][error] %s', e)
else:
nameservers.success(addr)
return inter_res
nameservers.fail(addr)
def on_connection_error(self, exc):
logger.debug('[connect_error] %s:%port', self.hostname or self.addr[0],
self.addr[1])
self.size -= 1
