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
|
# Copyright (c) 2016 Weitian LI <liweitianux@live.com>
# MIT license
"""
Communicate with the "fg21sim" simulation program through the Web UI using
the WebSocket_ protocol, which provides full-duplex communication channels
over a single TCP connection.
.. _WebSocket: https://en.wikipedia.org/wiki/WebSocket
References
----------
- Tornado WebSocket:
http://www.tornadoweb.org/en/stable/websocket.html
- Can I Use: WebSocket:
http://caniuse.com/#feat=websockets
"""
import json
import logging
import tornado.websocket
from tornado.options import options
from .console import ConsoleHandler
from .configs import ConfigsHandler
from ..utils import get_host_ip, ip_in_network
logger = logging.getLogger(__name__)
class FG21simWSHandler(tornado.websocket.WebSocketHandler):
"""
WebSocket for bi-directional communication between the Web UI and
the server, which can deal with the configurations and execute the
simulation task.
Generally, WebSocket send and receive data as *string*. Therefore,
the more complex data are stringified as JSON string before sending,
which will be parsed after receive.
Each message (as a JSON object or Python dictionary) has a ``type``
field which will be used to determine the following action to take.
Attributes
----------
name : str
Name to distinguish this WebSocket handle.
from_localhost : bool
Set to ``True`` if the access is from the localhost,
otherwise ``False``.
configs : `~ConfigManager`
A ``ConfigManager`` instance, for configuration manipulations when
communicating with the Web UI.
"""
name = "fg21sim"
from_localhost = None
def check_origin(self, origin):
"""
Check the origin of the WebSocket connection to determine whether
the access is allowed.
Attributes
----------
from_localhost : bool
Set to ``True`` if the access is from the "localhost" (i.e.,
127.0.0.1), otherwise ``False``.
"""
self.from_localhost = False
logger.info("WebSocket: {0}: origin: {1}".format(self.name, origin))
ip = get_host_ip(url=origin)
network = options.hosts_allowed
if ip == "127.0.0.1":
self.from_localhost = True
allow = True
logger.info("WebSocket: %s: origin is localhost" % self.name)
elif network.upper() == "ANY":
# Any hosts are allowed
allow = True
logger.warning("WebSocket: %s: any hosts are allowed" % self.name)
elif ip_in_network(ip, network):
allow = True
logger.info("WebSocket: %s: " % self.name +
"client is in the allowed network: %s" % network)
else:
allow = False
logger.error("WebSocket: %s: " % self.name +
"client is NOT in the allowed network: %s" % network)
return allow
def open(self):
"""Invoked when a new WebSocket is opened by the client."""
# Add to the set of current connected clients
self.application.ws_clients.add(self)
logger.warning("Added new WebSocket client: {0}".format(self))
# FIXME:
# * better to move to the `Application` class ??
self.configs = self.application.configmanager
self.console_handler = ConsoleHandler(websocket=self)
self.configs_handler = ConfigsHandler(configs=self.configs)
#
logger.info("WebSocket: {0}: opened".format(self.name))
logger.info("Allowed hosts: {0}".format(options.hosts_allowed))
def on_close(self):
"""Invoked when a new WebSocket is closed by the client."""
# Remove from the set of current connected clients
self.application.ws_clients.remove(self)
logger.warning("Removed WebSocket client: {0}".format(self))
code, reason = None, None
if hasattr(self, "close_code"):
code = self.close_code
if hasattr(self, "close_reason"):
reason = self.close_reason
logger.warning("WebSocket: {0}: closed by client: {1}, {2}".format(
self.name, code, reason))
# FIXME/XXX:
# * How to be non-blocking ??
# NOTE: WebSocket.on_message: may NOT be a coroutine at the moment (v4.3)
# References:
# [1] https://stackoverflow.com/a/35543856/4856091
# [2] https://stackoverflow.com/a/33724486/4856091
def on_message(self, message):
"""
Handle incoming messages and dispatch task according to the
message type.
NOTE
----
The received message (parsed to a Python dictionary) has a ``type``
item which will be used to determine the following action to take.
Currently supported message types are:
``configs``:
Request or set the configurations
``console``:
Control the simulation tasks, or request logging messages
``results``:
Request the simulation results
The sent message also has a ``type`` item of same value, which the
client can be used to figure out the proper actions.
There is a ``success`` item which indicates the status of the
requested operation, and an ``error`` recording the error message
if ``success=False``.
"""
logger.debug("WebSocket: %s: received: %s" % (self.name, message))
try:
msg = json.loads(message)
msg_type = msg["type"]
except json.JSONDecodeError:
logger.warning("WebSocket: {0}: ".format(self.name) +
"message is not a valid JSON string")
response = {"success": False,
"type": None,
"error": "message is not a valid JSON string"}
except (KeyError, TypeError):
logger.warning("WebSocket: %s: skip invalid message" % self.name)
response = {"success": False,
"type": None,
"error": "type is missing"}
else:
# Check the message type and dispatch task
if msg_type == "configs":
# Request or set the configurations
response = self.configs_handler.handle_message(msg)
elif msg_type == "console":
# Control the simulation tasks, or request logging messages
# FIXME/XXX:
# * How to make this asynchronously ??
response = self.console_handler.handle_message(msg)
elif msg_type == "results":
# Request the simulation results
response = self._handle_results(msg)
else:
# Message of unknown type
logger.warning("WebSocket: {0}: ".format(self.name) +
"unknown message type: {0}".format(msg_type))
response = {"success": False,
"type": msg_type,
"error": "unknown message type %s" % msg_type}
#
msg_response = json.dumps(response)
self.write_message(msg_response)
def broadcast(self, message):
"""Broadcast/push the given message to all connected clients."""
for ws in self.application.ws_clients:
ws.write_message(message)
def _handle_results(self, msg):
# Got a message of supported types
msg_type = msg["type"]
logger.info("WebSocket: {0}: ".format(self.name) +
"handle message of type: {0}".format(msg_type))
response = {"success": True, "type": msg_type}
return response
|
