class TelnetClient(ClientInterface):
def __init__(self, reader, writer):
self.reader = reader
self.writer = writer
self.remote_ip = writer.get_extra_info('peername')[0]
self.input_queue = asyncio.Queue()
self.output_queue = asyncio.Queue()
self.parser = TelnetParser(self.input_queue, self.output_queue,
self.remote_ip)
self.kill_switch = asyncio.Future()
@asyncio.coroutine
def close(self):
self.kill_switch.set_result(True)
@asyncio.coroutine
def _close(self):
"""
A coroutine that gracefully kicks the client
"""
self.writer.close()
@asyncio.coroutine
def get_input_async(self):
"""
A coroutine that returns the next message from the client
The message must be a Dictionary that at least specifies a command for
the controller.
"""
# {
# 'command': command,
# 'other_params': other_params
# }
msg = yield from self.parser.get_input_async()
return msg
@asyncio.coroutine
def put_output_async(self, msg):
"""
A coroutine that sends the specified message to the client
The message will be a Dictionary that echoes the client's command and
sends the results as a sub-item
"""
# {
# 'command': command,
# 'data': results
# }
yield from self.parser.put_output_async(msg)
@asyncio.coroutine
def communicate_until_closed(self):
logger.info("[{}] New telnet client.".format(self.remote_ip))
communication_tasks = [
asyncio. async (self._receive_to_queue()),
asyncio. async (self.parser.run_parser()),
asyncio. async (self._send_from_queue()), self.kill_switch
]
done, pending = yield from asyncio.wait(communication_tasks,
return_when=FIRST_COMPLETED)
logger.info("[{}] Cleaning up client...".format(self.remote_ip))
got_exception = None
for task in done:
e = task.exception()
if isinstance(e, TelnetExit):
# No need to handle this here; the client will be closed anyway.
pass
elif isinstance(e, Exception):
# If any of our tasks threw a different exception, re-raise it
# instead of failing silently.
got_exception = e
# Make sure we cancel the tasks in order, so that last minute
# messages can still get sent.
for task in communication_tasks:
if not task.done():
task.cancel()
# self.kill_switch is a simple Future; it doesn't need to
# clean up.
if task != self.kill_switch:
yield from task
yield from self._close()
logger.info("[{}] Cleanup complete.".format(self.remote_ip))
if got_exception is not None:
print(got_exception)
raise got_exception
@asyncio.coroutine
def _receive_to_queue(self):
try:
while True:
msg = yield from self.reader.readline()
# "If the EOF was received and the internal buffer is empty,
# return an empty bytes object."
if msg == b'':
logger.info("[{}] Client connection closed.".format(
self.remote_ip))
break
logger.info("[{}] [RECV] {}".format(self.remote_ip, msg))
yield from self.input_queue.put(msg)
except CancelledError:
logger.debug("[{}] Cancelling receiver...".format(self.remote_ip))
@asyncio.coroutine
def _send_from_queue(self):
preview_length = 80
# ======================================
@asyncio.coroutine
def execute(msg):
msg_preview = (msg[0:preview_length].replace('\n', '\\n').replace(
'\r', '\\r'))
if len(msg) > preview_length:
msg_preview += "..."
self.writer.write(msg.encode())
yield from self.writer.drain()
logger.info("[{}] [SEND] {}".format(self.remote_ip, msg_preview))
# ======================================
try:
while True:
msg = yield from self.output_queue.get()
yield from execute(msg)
except CancelledError:
logger.debug("[{}] Cancelling sender...".format(self.remote_ip))
# Goodbye, client
yield from self.output_queue.put("Server closing connection -- "
"Goodbye.")
while self.output_queue.qsize() > 0:
msg = self.output_queue.get_nowait()
yield from execute(msg)
class TelnetClient(ClientInterface):
def __init__(self, reader, writer):
self.reader = reader
self.writer = writer
self.remote_ip = writer.get_extra_info("peername")[0]
self.input_queue = asyncio.Queue()
self.output_queue = asyncio.Queue()
self.parser = TelnetParser(self.input_queue, self.output_queue, self.remote_ip)
self.kill_switch = asyncio.Future()
@asyncio.coroutine
def close(self):
self.kill_switch.set_result(True)
@asyncio.coroutine
def _close(self):
"""
A coroutine that gracefully kicks the client
"""
self.writer.close()
@asyncio.coroutine
def get_input_async(self):
"""
A coroutine that returns the next message from the client
The message must be a Dictionary that at least specifies a command for
the controller.
"""
# {
# 'command': command,
# 'other_params': other_params
# }
msg = yield from self.parser.get_input_async()
return msg
@asyncio.coroutine
def put_output_async(self, msg):
"""
A coroutine that sends the specified message to the client
The message will be a Dictionary that echoes the client's command and
sends the results as a sub-item
"""
# {
# 'command': command,
# 'data': results
# }
yield from self.parser.put_output_async(msg)
@asyncio.coroutine
def communicate_until_closed(self):
logger.info("[{}] New telnet client.".format(self.remote_ip))
communication_tasks = [
asyncio.async(self._receive_to_queue()),
asyncio.async(self.parser.run_parser()),
asyncio.async(self._send_from_queue()),
self.kill_switch,
]
done, pending = yield from asyncio.wait(communication_tasks, return_when=FIRST_COMPLETED)
logger.info("[{}] Cleaning up client...".format(self.remote_ip))
got_exception = None
for task in done:
e = task.exception()
if isinstance(e, TelnetExit):
# No need to handle this here; the client will be closed anyway.
pass
elif isinstance(e, Exception):
# If any of our tasks threw a different exception, re-raise it
# instead of failing silently.
got_exception = e
# Make sure we cancel the tasks in order, so that last minute
# messages can still get sent.
for task in communication_tasks:
if not task.done():
task.cancel()
# self.kill_switch is a simple Future; it doesn't need to
# clean up.
if task != self.kill_switch:
yield from task
yield from self._close()
logger.info("[{}] Cleanup complete.".format(self.remote_ip))
if got_exception is not None:
print(got_exception)
raise got_exception
@asyncio.coroutine
def _receive_to_queue(self):
try:
while True:
msg = yield from self.reader.readline()
# "If the EOF was received and the internal buffer is empty,
# return an empty bytes object."
if msg == b"":
logger.info("[{}] Client connection closed.".format(self.remote_ip))
break
logger.info("[{}] [RECV] {}".format(self.remote_ip, msg))
yield from self.input_queue.put(msg)
except CancelledError:
logger.debug("[{}] Cancelling receiver...".format(self.remote_ip))
@asyncio.coroutine
def _send_from_queue(self):
preview_length = 80
# ======================================
@asyncio.coroutine
def execute(msg):
msg_preview = msg[0:preview_length].replace("\n", "\\n").replace("\r", "\\r")
if len(msg) > preview_length:
msg_preview += "..."
self.writer.write(msg.encode())
yield from self.writer.drain()
logger.info("[{}] [SEND] {}".format(self.remote_ip, msg_preview))
# ======================================
try:
while True:
msg = yield from self.output_queue.get()
yield from execute(msg)
except CancelledError:
logger.debug("[{}] Cancelling sender...".format(self.remote_ip))
# Goodbye, client
yield from self.output_queue.put("Server closing connection -- " "Goodbye.")
while self.output_queue.qsize() > 0:
msg = self.output_queue.get_nowait()
yield from execute(msg)