/usr/lib/pwrkap/sockmux.py is in pwrkap 7.30-5.
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 | #!/usr/bin/python
"""Multiplex various sockets to a single command channel."""
# (C) Copyright IBM Corp. 2008-2009
# Licensed under the GPLv2.
import select
import socket
import sys
import thread
import struct
import traceback
import os
import cPickle as pickle
def res_unavailable_error(err):
"""Determine if the error is due to lack of resource availability."""
if isinstance(err, socket.error) and err[0] == 11:
return True
return False
READ_BUFFER_SIZE = 1
class sockmux:
"""Multiplexer that sends objects from an input channel to sockets
and from sockets to the controller."""
def __init__(self, controller, listen_port):
"""Create a socket mux with a controller and a given listening port."""
self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
print "Listening on port %d" % listen_port
self.server_socket.bind(('0.0.0.0', listen_port))
self.server_socket.listen(5)
self.controller = controller
self.should_close = False
self.queues = {}
self.in_buffers = {}
self.pipe = os.pipe()
self.pipe_read = os.fdopen(self.pipe[0], "r")
self.pipe_write = os.fdopen(self.pipe[1], "w")
# This MUST come last!
thread.start_new_thread(self.run, ())
def run(self):
"""Run the mux."""
self.should_close = False
while not self.should_close:
try:
self.run_once()
except Exception, e:
print e
self.server_socket.shutdown(socket.SHUT_RDWR)
self.server_socket.close()
for cs in self.queues.keys():
cs.shutdown(socket.SHUT_RDWR)
cs.close()
self.pipe_read.close()
self.pipe_write.close()
def shut_down(self):
"""Deactivate the mux."""
self.should_close = True
def write(self, object):
"""Write an object to all outputs."""
for cs in self.queues.keys():
queue = self.queues[cs]
queue.append(object)
# Wake up select()
self.pipe_write.write("0")
self.pipe_write.flush()
def kill_socket(self, cs):
"""Terminate a socket."""
del self.queues[cs]
del self.in_buffers[cs]
cs.shutdown(socket.SHUT_RDWR)
cs.close()
def run_once(self):
"""Shovel objects between controller and sockets."""
def write_socket(cs, queue):
"""Write something to a socket."""
try:
assert len(queue) > 0
obj = queue[0]
objlen = len(obj)
sent = cs.send(obj)
while sent != 0:
if objlen == sent:
del queue[0]
else:
queue[0] = obj[sent:]
if len(queue) == 0:
return
obj = queue[0]
objlen = len(obj)
sent = cs.send(obj)
except Exception, e:
# Don't fault on -EAGAIN
if res_unavailable_error(e):
return
print e
traceback.print_exc()
self.kill_socket(cs)
def read_socket(cs):
"""Read something from a socket."""
global READ_BUFFER_SIZE
try:
buffer = self.in_buffers[cs]
str = cs.recv(1)
# Readable but no data == EOF
if len(str) == 0:
raise EOFError()
while len(str) > 0:
buffer = buffer + str
try:
obj = pickle.loads(buffer)
self.in_buffers[cs] = ""
self.controller.command(obj)
except:
self.in_buffers[cs] = buffer
pass
str = cs.recv(1)
except Exception, e:
# Don't kill socket if -EAGAIN
if res_unavailable_error(e):
return
print e
traceback.print_exc(file=sys.stdout)
self.kill_socket(cs)
readers = [self.pipe_read, self.server_socket]
writers = []
exceptions = []
# Nominate all sockets with pending writes for select, and
# all sockets for reads
for cs in self.queues.keys():
queue = self.queues[cs]
readers.append(cs)
exceptions.append(cs)
if len(queue) > 0:
writers.append(cs)
# Find sockets that aren't blocked
#print ("before: ", readers, writers, exceptions)
(r, w, x) = select.select(readers, writers, exceptions)
#print ("after: ", r, w, x)
assert len(x) == 0
# If someone connects, tell the controller and add the
# socket to our list.
if self.server_socket in r:
try:
(cs, addr) = self.server_socket.accept()
print (cs, addr)
cs.setblocking(0)
queue = []
res = self.controller.connect(cs, queue)
if not res:
cs.shutdown(socket.SHUT_RDWR)
cs.close()
else:
self.queues[cs] = queue
self.in_buffers[cs] = ""
except socket.error:
pass
# For all writers that can be written, write queued data
for cs in w:
queue = self.queues[cs]
write_socket(cs, queue)
# For all reader sockets...
for cs in r:
if cs == self.pipe_read:
x = self.pipe_read.read(1)
continue
if cs == self.server_socket:
continue
read_socket(cs)
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