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
|
#
# VPP Unix Domain Socket Transport.
#
import socket
import struct
import threading
import select
import multiprocessing
try:
import queue as queue
except ImportError:
import Queue as queue
import logging
class VppTransportSocketIOError(IOError):
pass
class VppTransport(object):
VppTransportSocketIOError = VppTransportSocketIOError
def __init__(self, parent, read_timeout, server_address):
self.connected = False
self.read_timeout = read_timeout if read_timeout > 0 else 1
self.parent = parent
self.server_address = server_address
self.header = struct.Struct('>QII')
self.message_table = {}
self.sque = multiprocessing.Queue()
self.q = multiprocessing.Queue()
self.message_thread = threading.Thread(target=self.msg_thread_func)
def msg_thread_func(self):
while True:
try:
rlist, _, _ = select.select([self.socket,
self.sque._reader], [], [])
except socket.error:
# Terminate thread
logging.error('select failed')
self.q.put(None)
return
for r in rlist:
if r == self.sque._reader:
# Terminate
self.q.put(None)
return
elif r == self.socket:
try:
msg = self._read()
if not msg:
self.q.put(None)
return
except socket.error:
self.q.put(None)
return
# Put either to local queue or if context == 0
# callback queue
if self.parent.has_context(msg):
self.q.put(msg)
else:
self.parent.msg_handler_async(msg)
else:
raise VppTransportSocketIOError(
2, 'Unknown response from select')
def connect(self, name, pfx, msg_handler, rx_qlen):
# Create a UDS socket
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_SEQPACKET)
self.socket.settimeout(self.read_timeout)
# Connect the socket to the port where the server is listening
try:
self.socket.connect(self.server_address)
except socket.error as msg:
logging.error("{} on socket {}".format(msg, self.server_address))
raise
self.connected = True
# Initialise sockclnt_create
sockclnt_create = self.parent.messages['sockclnt_create']
sockclnt_create_reply = self.parent.messages['sockclnt_create_reply']
args = {'_vl_msg_id': 15,
'name': name,
'context': 124}
b = sockclnt_create.pack(args)
self.write(b)
msg = self._read()
hdr, length = self.parent.header.unpack(msg, 0)
if hdr.msgid != 16:
raise VppTransportSocketIOError('Invalid reply message')
r, length = sockclnt_create_reply.unpack(msg)
self.socket_index = r.index
for m in r.message_table:
n = m.name.rstrip(b'\x00\x13')
self.message_table[n] = m.index
self.message_thread.daemon = True
self.message_thread.start()
return 0
def disconnect(self):
rv = 0
try: # Might fail, if VPP closes socket before packet makes it out
rv = self.parent.api.sockclnt_delete(index=self.socket_index)
except IOError:
pass
self.connected = False
self.socket.close()
self.sque.put(True) # Terminate listening thread
self.message_thread.join()
return rv
def suspend(self):
pass
def resume(self):
pass
def callback(self):
raise NotImplementedError
def get_callback(self, do_async):
return self.callback
def get_msg_index(self, name):
try:
return self.message_table[name]
except KeyError:
return 0
def msg_table_max_index(self):
return len(self.message_table)
def write(self, buf):
"""Send a binary-packed message to VPP."""
if not self.connected:
raise VppTransportSocketIOError(1, 'Not connected')
# Send header
header = self.header.pack(0, len(buf), 0)
n = self.socket.send(header)
n = self.socket.send(buf)
def _read(self):
# Header and message
try:
msg = self.socket.recv(4096)
if len(msg) == 0:
return None
except socket.error as message:
logging.error(message)
raise
(_, l, _) = self.header.unpack(msg[:16])
if l > len(msg):
buf = bytearray(l + 16)
view = memoryview(buf)
view[:4096] = msg
view = view[4096:]
# Read rest of message
remaining_bytes = l - 4096 + 16
while remaining_bytes > 0:
bytes_to_read = (remaining_bytes if remaining_bytes
<= 4096 else 4096)
nbytes = self.socket.recv_into(view, bytes_to_read)
if nbytes == 0:
logging.error('recv failed')
break
view = view[nbytes:]
remaining_bytes -= nbytes
else:
buf = msg
return buf[16:]
def read(self):
if not self.connected:
raise VppTransportSocketIOError(1, 'Not connected')
try:
return self.q.get(True, self.read_timeout)
except queue.Empty:
return None
|
