/usr/share/pyshared/ovs/stream.py is in python-openvswitch 1.4.2+git20120612-9.1~deb7u1.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 | # Copyright (c) 2010, 2011 Nicira Networks
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import errno
import os
import select
import socket
import ovs.poller
import ovs.socket_util
import ovs.vlog
vlog = ovs.vlog.Vlog("stream")
class Stream(object):
"""Bidirectional byte stream. Currently only Unix domain sockets
are implemented."""
n_unix_sockets = 0
# States.
__S_CONNECTING = 0
__S_CONNECTED = 1
__S_DISCONNECTED = 2
# Kinds of events that one might wait for.
W_CONNECT = 0 # Connect complete (success or failure).
W_RECV = 1 # Data received.
W_SEND = 2 # Send buffer room available.
@staticmethod
def is_valid_name(name):
"""Returns True if 'name' is a stream name in the form "TYPE:ARGS" and
TYPE is a supported stream type (currently only "unix:"), otherwise
False."""
return name.startswith("unix:")
def __init__(self, socket, name, bind_path, status):
self.socket = socket
self.name = name
self.bind_path = bind_path
if status == errno.EAGAIN:
self.state = Stream.__S_CONNECTING
elif status == 0:
self.state = Stream.__S_CONNECTED
else:
self.state = Stream.__S_DISCONNECTED
self.error = 0
@staticmethod
def open(name):
"""Attempts to connect a stream to a remote peer. 'name' is a
connection name in the form "TYPE:ARGS", where TYPE is an active stream
class's name and ARGS are stream class-specific. Currently the only
supported TYPE is "unix".
Returns (error, stream): on success 'error' is 0 and 'stream' is the
new Stream, on failure 'error' is a positive errno value and 'stream'
is None.
Never returns errno.EAGAIN or errno.EINPROGRESS. Instead, returns 0
and a new Stream. The connect() method can be used to check for
successful connection completion."""
if not Stream.is_valid_name(name):
return errno.EAFNOSUPPORT, None
Stream.n_unix_sockets += 1
bind_path = "/tmp/stream-unix.%d.%d" % (os.getpid(),
Stream.n_unix_sockets)
connect_path = name[5:]
error, sock = ovs.socket_util.make_unix_socket(socket.SOCK_STREAM,
True, bind_path,
connect_path)
if error:
return error, None
else:
status = ovs.socket_util.check_connection_completion(sock)
return 0, Stream(sock, name, bind_path, status)
@staticmethod
def open_block((error, stream)):
"""Blocks until a Stream completes its connection attempt, either
succeeding or failing. (error, stream) should be the tuple returned by
Stream.open(). Returns a tuple of the same form.
Typical usage:
error, stream = Stream.open_block(Stream.open("unix:/tmp/socket"))"""
if not error:
while True:
error = stream.connect()
if error != errno.EAGAIN:
break
stream.run()
poller = ovs.poller.Poller()
stream.run_wait()
stream.connect_wait(poller)
poller.block()
assert error != errno.EINPROGRESS
if error and stream:
stream.close()
stream = None
return error, stream
def close(self):
self.socket.close()
if self.bind_path is not None:
ovs.fatal_signal.unlink_file_now(self.bind_path)
self.bind_path = None
def __scs_connecting(self):
retval = ovs.socket_util.check_connection_completion(self.socket)
assert retval != errno.EINPROGRESS
if retval == 0:
self.state = Stream.__S_CONNECTED
elif retval != errno.EAGAIN:
self.state = Stream.__S_DISCONNECTED
self.error = retval
def connect(self):
"""Tries to complete the connection on this stream. If the connection
is complete, returns 0 if the connection was successful or a positive
errno value if it failed. If the connection is still in progress,
returns errno.EAGAIN."""
last_state = -1 # Always differs from initial self.state
while self.state != last_state:
last_state = self.state
if self.state == Stream.__S_CONNECTING:
self.__scs_connecting()
elif self.state == Stream.__S_CONNECTED:
return 0
elif self.state == Stream.__S_DISCONNECTED:
return self.error
def recv(self, n):
"""Tries to receive up to 'n' bytes from this stream. Returns a
(error, string) tuple:
- If successful, 'error' is zero and 'string' contains between 1
and 'n' bytes of data.
- On error, 'error' is a positive errno value.
- If the connection has been closed in the normal fashion or if 'n'
is 0, the tuple is (0, "").
The recv function will not block waiting for data to arrive. If no
data have been received, it returns (errno.EAGAIN, "") immediately."""
retval = self.connect()
if retval != 0:
return (retval, "")
elif n == 0:
return (0, "")
try:
return (0, self.socket.recv(n))
except socket.error, e:
return (ovs.socket_util.get_exception_errno(e), "")
def send(self, buf):
"""Tries to send 'buf' on this stream.
If successful, returns the number of bytes sent, between 1 and
len(buf). 0 is only a valid return value if len(buf) is 0.
On error, returns a negative errno value.
Will not block. If no bytes can be immediately accepted for
transmission, returns -errno.EAGAIN immediately."""
retval = self.connect()
if retval != 0:
return -retval
elif len(buf) == 0:
return 0
try:
return self.socket.send(buf)
except socket.error, e:
return -ovs.socket_util.get_exception_errno(e)
def run(self):
pass
def run_wait(self, poller):
pass
def wait(self, poller, wait):
assert wait in (Stream.W_CONNECT, Stream.W_RECV, Stream.W_SEND)
if self.state == Stream.__S_DISCONNECTED:
poller.immediate_wake()
return
if self.state == Stream.__S_CONNECTING:
wait = Stream.W_CONNECT
if wait == Stream.W_RECV:
poller.fd_wait(self.socket, select.POLLIN)
else:
poller.fd_wait(self.socket, select.POLLOUT)
def connect_wait(self, poller):
self.wait(poller, Stream.W_CONNECT)
def recv_wait(self, poller):
self.wait(poller, Stream.W_RECV)
def send_wait(self, poller):
self.wait(poller, Stream.W_SEND)
def __del__(self):
# Don't delete the file: we might have forked.
self.socket.close()
class PassiveStream(object):
@staticmethod
def is_valid_name(name):
"""Returns True if 'name' is a passive stream name in the form
"TYPE:ARGS" and TYPE is a supported passive stream type (currently only
"punix:"), otherwise False."""
return name.startswith("punix:")
def __init__(self, sock, name, bind_path):
self.name = name
self.socket = sock
self.bind_path = bind_path
@staticmethod
def open(name):
"""Attempts to start listening for remote stream connections. 'name'
is a connection name in the form "TYPE:ARGS", where TYPE is an passive
stream class's name and ARGS are stream class-specific. Currently the
only supported TYPE is "punix".
Returns (error, pstream): on success 'error' is 0 and 'pstream' is the
new PassiveStream, on failure 'error' is a positive errno value and
'pstream' is None."""
if not PassiveStream.is_valid_name(name):
return errno.EAFNOSUPPORT, None
bind_path = name[6:]
error, sock = ovs.socket_util.make_unix_socket(socket.SOCK_STREAM,
True, bind_path, None)
if error:
return error, None
try:
sock.listen(10)
except socket.error, e:
vlog.err("%s: listen: %s" % (name, os.strerror(e.error)))
sock.close()
return e.error, None
return 0, PassiveStream(sock, name, bind_path)
def close(self):
"""Closes this PassiveStream."""
self.socket.close()
if self.bind_path is not None:
ovs.fatal_signal.unlink_file_now(self.bind_path)
self.bind_path = None
def accept(self):
"""Tries to accept a new connection on this passive stream. Returns
(error, stream): if successful, 'error' is 0 and 'stream' is the new
Stream object, and on failure 'error' is a positive errno value and
'stream' is None.
Will not block waiting for a connection. If no connection is ready to
be accepted, returns (errno.EAGAIN, None) immediately."""
while True:
try:
sock, addr = self.socket.accept()
ovs.socket_util.set_nonblocking(sock)
return 0, Stream(sock, "unix:%s" % addr, None, 0)
except socket.error, e:
error = ovs.socket_util.get_exception_errno(e)
if error != errno.EAGAIN:
# XXX rate-limit
vlog.dbg("accept: %s" % os.strerror(error))
return error, None
def wait(self, poller):
poller.fd_wait(self.socket, select.POLLIN)
def __del__(self):
# Don't delete the file: we might have forked.
self.socket.close()
def usage(name):
return """
Active %s connection methods:
unix:FILE Unix domain socket named FILE
Passive %s connection methods:
punix:FILE Listen on Unix domain socket FILE""" % (name, name)
|