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#
# SPDX-License-Identifier: GPL-2.0-only
#
import abc
import asyncio
import json
import os
import signal
import socket
import sys
from . import chunkify, DEFAULT_MAX_CHUNK
class ClientError(Exception):
pass
class ServerError(Exception):
pass
class AsyncServerConnection(object):
def __init__(self, reader, writer, proto_name, logger):
self.reader = reader
self.writer = writer
self.proto_name = proto_name
self.max_chunk = DEFAULT_MAX_CHUNK
self.handlers = {
'chunk-stream': self.handle_chunk,
}
self.logger = logger
async def process_requests(self):
try:
self.addr = self.writer.get_extra_info('peername')
self.logger.debug('Client %r connected' % (self.addr,))
# Read protocol and version
client_protocol = await self.reader.readline()
if client_protocol is None:
return
(client_proto_name, client_proto_version) = client_protocol.decode('utf-8').rstrip().split()
if client_proto_name != self.proto_name:
self.logger.debug('Rejecting invalid protocol %s' % (self.proto_name))
return
self.proto_version = tuple(int(v) for v in client_proto_version.split('.'))
if not self.validate_proto_version():
self.logger.debug('Rejecting invalid protocol version %s' % (client_proto_version))
return
# Read headers. Currently, no headers are implemented, so look for
# an empty line to signal the end of the headers
while True:
line = await self.reader.readline()
if line is None:
return
line = line.decode('utf-8').rstrip()
if not line:
break
# Handle messages
while True:
d = await self.read_message()
if d is None:
break
await self.dispatch_message(d)
await self.writer.drain()
except ClientError as e:
self.logger.error(str(e))
finally:
self.writer.close()
async def dispatch_message(self, msg):
for k in self.handlers.keys():
if k in msg:
self.logger.debug('Handling %s' % k)
await self.handlers[k](msg[k])
return
raise ClientError("Unrecognized command %r" % msg)
def write_message(self, msg):
for c in chunkify(json.dumps(msg), self.max_chunk):
self.writer.write(c.encode('utf-8'))
async def read_message(self):
l = await self.reader.readline()
if not l:
return None
try:
message = l.decode('utf-8')
if not message.endswith('\n'):
return None
return json.loads(message)
except (json.JSONDecodeError, UnicodeDecodeError) as e:
self.logger.error('Bad message from client: %r' % message)
raise e
async def handle_chunk(self, request):
lines = []
try:
while True:
l = await self.reader.readline()
l = l.rstrip(b"\n").decode("utf-8")
if not l:
break
lines.append(l)
msg = json.loads(''.join(lines))
except (json.JSONDecodeError, UnicodeDecodeError) as e:
self.logger.error('Bad message from client: %r' % lines)
raise e
if 'chunk-stream' in msg:
raise ClientError("Nested chunks are not allowed")
await self.dispatch_message(msg)
class AsyncServer(object):
def __init__(self, logger, loop=None):
if loop is None:
self.loop = asyncio.new_event_loop()
self.close_loop = True
else:
self.loop = loop
self.close_loop = False
self._cleanup_socket = None
self.logger = logger
def start_tcp_server(self, host, port):
self.server = self.loop.run_until_complete(
asyncio.start_server(self.handle_client, host, port, loop=self.loop)
)
for s in self.server.sockets:
self.logger.info('Listening on %r' % (s.getsockname(),))
# Newer python does this automatically. Do it manually here for
# maximum compatibility
s.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
s.setsockopt(socket.SOL_TCP, socket.TCP_QUICKACK, 1)
name = self.server.sockets[0].getsockname()
if self.server.sockets[0].family == socket.AF_INET6:
self.address = "[%s]:%d" % (name[0], name[1])
else:
self.address = "%s:%d" % (name[0], name[1])
def start_unix_server(self, path):
def cleanup():
os.unlink(path)
cwd = os.getcwd()
try:
# Work around path length limits in AF_UNIX
os.chdir(os.path.dirname(path))
self.server = self.loop.run_until_complete(
asyncio.start_unix_server(self.handle_client, os.path.basename(path), loop=self.loop)
)
finally:
os.chdir(cwd)
self.logger.info('Listening on %r' % path)
self._cleanup_socket = cleanup
self.address = "unix://%s" % os.path.abspath(path)
@abc.abstractmethod
def accept_client(self, reader, writer):
pass
async def handle_client(self, reader, writer):
# writer.transport.set_write_buffer_limits(0)
try:
client = self.accept_client(reader, writer)
await client.process_requests()
except Exception as e:
import traceback
self.logger.error('Error from client: %s' % str(e), exc_info=True)
traceback.print_exc()
writer.close()
self.logger.info('Client disconnected')
def run_loop_forever(self):
try:
self.loop.run_forever()
except KeyboardInterrupt:
pass
def signal_handler(self):
self.loop.stop()
def serve_forever(self):
asyncio.set_event_loop(self.loop)
try:
self.loop.add_signal_handler(signal.SIGTERM, self.signal_handler)
self.run_loop_forever()
self.server.close()
self.loop.run_until_complete(self.server.wait_closed())
self.logger.info('Server shutting down')
finally:
if self.close_loop:
if sys.version_info >= (3, 6):
self.loop.run_until_complete(self.loop.shutdown_asyncgens())
self.loop.close()
if self._cleanup_socket is not None:
self._cleanup_socket()
|
