1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
#
# 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()
|