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
|
# QEMU Monitor Protocol Python class
#
# Copyright (C) 2009, 2010 Red Hat Inc.
#
# Authors:
# Luiz Capitulino <lcapitulino@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2. See
# the COPYING file in the top-level directory.
import json
import errno
import socket
class QMPError(Exception):
pass
class QMPConnectError(QMPError):
pass
class QMPCapabilitiesError(QMPError):
pass
class QEMUMonitorProtocol:
def __init__(self, address, server=False):
"""
Create a QEMUMonitorProtocol class.
@param address: QEMU address, can be either a unix socket path (string)
or a tuple in the form ( address, port ) for a TCP
connection
@param server: server mode listens on the socket (bool)
@raise socket.error on socket connection errors
@note No connection is established, this is done by the connect() or
accept() methods
"""
self.__events = []
self.__address = address
self.__sock = self.__get_sock()
if server:
self.__sock.bind(self.__address)
self.__sock.listen(1)
def __get_sock(self):
if isinstance(self.__address, tuple):
family = socket.AF_INET
else:
family = socket.AF_UNIX
return socket.socket(family, socket.SOCK_STREAM)
def __negotiate_capabilities(self):
greeting = self.__json_read()
if greeting is None or not greeting.has_key('QMP'):
raise QMPConnectError
# Greeting seems ok, negotiate capabilities
resp = self.cmd('qmp_capabilities')
if "return" in resp:
return greeting
raise QMPCapabilitiesError
def __json_read(self, only_event=False):
while True:
data = self.__sockfile.readline()
if not data:
return
resp = json.loads(data)
if 'event' in resp:
self.__events.append(resp)
if not only_event:
continue
return resp
error = socket.error
def connect(self, negotiate=True):
"""
Connect to the QMP Monitor and perform capabilities negotiation.
@return QMP greeting dict
@raise socket.error on socket connection errors
@raise QMPConnectError if the greeting is not received
@raise QMPCapabilitiesError if fails to negotiate capabilities
"""
self.__sock.connect(self.__address)
self.__sockfile = self.__sock.makefile()
if negotiate:
return self.__negotiate_capabilities()
def accept(self):
"""
Await connection from QMP Monitor and perform capabilities negotiation.
@return QMP greeting dict
@raise socket.error on socket connection errors
@raise QMPConnectError if the greeting is not received
@raise QMPCapabilitiesError if fails to negotiate capabilities
"""
self.__sock, _ = self.__sock.accept()
return self.__negotiate_capabilities()
def cmd_obj(self, qmp_cmd):
"""
Send a QMP command to the QMP Monitor.
@param qmp_cmd: QMP command to be sent as a Python dict
@return QMP response as a Python dict or None if the connection has
been closed
"""
try:
self.__sock.sendall(json.dumps(qmp_cmd))
except socket.error, err:
if err[0] == errno.EPIPE:
return
raise socket.error(err)
return self.__json_read()
def cmd(self, name, args=None, id=None):
"""
Build a QMP command and send it to the QMP Monitor.
@param name: command name (string)
@param args: command arguments (dict)
@param id: command id (dict, list, string or int)
"""
qmp_cmd = { 'execute': name }
if args:
qmp_cmd['arguments'] = args
if id:
qmp_cmd['id'] = id
return self.cmd_obj(qmp_cmd)
def command(self, cmd, **kwds):
ret = self.cmd(cmd, kwds)
if ret.has_key('error'):
raise Exception(ret['error']['desc'])
return ret['return']
def get_events(self, wait=False):
"""
Get a list of available QMP events.
@param wait: block until an event is available (bool)
"""
self.__sock.setblocking(0)
try:
self.__json_read()
except socket.error, err:
if err[0] == errno.EAGAIN:
# No data available
pass
self.__sock.setblocking(1)
if not self.__events and wait:
self.__json_read(only_event=True)
return self.__events
def clear_events(self):
"""
Clear current list of pending events.
"""
self.__events = []
def close(self):
self.__sock.close()
self.__sockfile.close()
|
