Move Node functions into their own file
Nodes include Switch, Host, and Controller; move these to a separate file. This file still could use some attention to hide private functions. Node seems like a primary class to extend, for adding stuff like Open vSwitch, so it could benefit from a simpler interface.
This commit is contained in:
Brandon Heller
+338
@@ -0,0 +1,338 @@
|
||||
#!/usr/bin/env python
|
||||
'''Node objects for Mininet.'''
|
||||
|
||||
from subprocess import Popen, PIPE, STDOUT
|
||||
import os, signal, sys, select
|
||||
flush = sys.stdout.flush
|
||||
|
||||
from mininet.logging_mod import lg
|
||||
from mininet.util import quietRun
|
||||
|
||||
class Node(object):
|
||||
'''A virtual network node is simply a shell in a network namespace.
|
||||
We communicate with it using pipes.'''
|
||||
inToNode = {}
|
||||
outToNode = {}
|
||||
|
||||
def __init__(self, name, inNamespace = True):
|
||||
self.name = name
|
||||
closeFds = False # speed vs. memory use
|
||||
# xpg_echo is needed so we can echo our sentinel in sendCmd
|
||||
cmd = ['/bin/bash', '-O', 'xpg_echo']
|
||||
self.inNamespace = inNamespace
|
||||
if self.inNamespace:
|
||||
cmd = ['netns'] + cmd
|
||||
self.shell = Popen(cmd, stdin = PIPE, stdout = PIPE, stderr = STDOUT,
|
||||
close_fds = closeFds)
|
||||
self.stdin = self.shell.stdin
|
||||
self.stdout = self.shell.stdout
|
||||
self.pollOut = select.poll()
|
||||
self.pollOut.register(self.stdout)
|
||||
# Maintain mapping between file descriptors and nodes
|
||||
# This could be useful for monitoring multiple nodes
|
||||
# using select.poll()
|
||||
self.outToNode[self.stdout.fileno()] = self
|
||||
self.inToNode[self.stdin.fileno()] = self
|
||||
self.pid = self.shell.pid
|
||||
self.intfCount = 0
|
||||
self.intfs = [] # list of interface names, as strings
|
||||
self.ips = {}
|
||||
self.connection = {}
|
||||
self.waiting = False
|
||||
self.execed = False
|
||||
|
||||
def fdToNode(self, f):
|
||||
'''Insert docstring.
|
||||
|
||||
@param f unknown
|
||||
@return bool unknown
|
||||
'''
|
||||
node = self.outToNode.get(f)
|
||||
return node or self.inToNode.get(f)
|
||||
|
||||
def cleanup(self):
|
||||
'''Help python collect its garbage.'''
|
||||
self.shell = None
|
||||
|
||||
# Subshell I/O, commands and control
|
||||
def read(self, fileno_max):
|
||||
'''Insert docstring.
|
||||
|
||||
@param fileno_max unknown
|
||||
'''
|
||||
return os.read(self.stdout.fileno(), fileno_max)
|
||||
|
||||
def write(self, data):
|
||||
'''Write data to node.
|
||||
|
||||
@param data string
|
||||
'''
|
||||
os.write(self.stdin.fileno(), data)
|
||||
|
||||
def terminate(self):
|
||||
'''Send kill signal to Node and cleanup after it.'''
|
||||
os.kill(self.pid, signal.SIGKILL)
|
||||
self.cleanup()
|
||||
|
||||
def stop(self):
|
||||
'''Stop node.'''
|
||||
self.terminate()
|
||||
|
||||
def waitReadable(self):
|
||||
'''Poll on node.'''
|
||||
self.pollOut.poll()
|
||||
|
||||
def sendCmd(self, cmd):
|
||||
'''Send a command, followed by a command to echo a sentinel,
|
||||
and return without waiting for the command to complete.'''
|
||||
assert not self.waiting
|
||||
if cmd[-1] == '&':
|
||||
separator = '&'
|
||||
cmd = cmd[:-1]
|
||||
else:
|
||||
separator = ';'
|
||||
if isinstance(cmd, list):
|
||||
cmd = ' '.join(cmd)
|
||||
self.write(cmd + separator + ' echo -n "\\0177" \n')
|
||||
self.waiting = True
|
||||
|
||||
def monitor(self):
|
||||
'''Monitor the output of a command, returning (done, data).'''
|
||||
assert self.waiting
|
||||
self.waitReadable()
|
||||
data = self.read(1024)
|
||||
if len(data) > 0 and data[-1] == chr(0177):
|
||||
self.waiting = False
|
||||
return True, data[:-1]
|
||||
else:
|
||||
return False, data
|
||||
|
||||
def sendInt(self):
|
||||
'''Send ^C, hopefully interrupting a running subprocess.'''
|
||||
self.write(chr(3))
|
||||
|
||||
def waitOutput(self):
|
||||
'''Wait for a command to complete.
|
||||
|
||||
Completion is signaled by a sentinel character, ASCII(127) appearing in
|
||||
the output stream. Wait for the sentinel and return the output,
|
||||
including trailing newline.
|
||||
'''
|
||||
assert self.waiting
|
||||
output = ''
|
||||
while True:
|
||||
self.waitReadable()
|
||||
data = self.read(1024)
|
||||
if len(data) > 0 and data[-1] == chr(0177):
|
||||
output += data[:-1]
|
||||
break
|
||||
else: output += data
|
||||
self.waiting = False
|
||||
return output
|
||||
|
||||
def cmd(self, cmd):
|
||||
'''Send a command, wait for output, and return it.
|
||||
|
||||
@param cmd string
|
||||
'''
|
||||
self.sendCmd(cmd)
|
||||
return self.waitOutput()
|
||||
|
||||
def cmdPrint(self, cmd):
|
||||
'''Call cmd and printing its output
|
||||
|
||||
@param cmd string
|
||||
'''
|
||||
#lg.info('*** %s : %s', self.name, cmd)
|
||||
result = self.cmd(cmd)
|
||||
#lg.info('%s\n', result)
|
||||
return result
|
||||
|
||||
# Interface management, configuration, and routing
|
||||
def intfName(self, n):
|
||||
'''Construct a canonical interface name node-intf for interface N.'''
|
||||
return self.name + '-eth' + repr(n)
|
||||
|
||||
def newIntf(self):
|
||||
'''Reserve and return a new interface name.'''
|
||||
intfName = self.intfName(self.intfCount)
|
||||
self.intfCount += 1
|
||||
self.intfs += [intfName]
|
||||
return intfName
|
||||
|
||||
def setIP(self, intf, ip, bits):
|
||||
'''Set the IP address for an interface.
|
||||
|
||||
@param intf string, interface name
|
||||
@param ip IP address as integer
|
||||
@param bits
|
||||
'''
|
||||
result = self.cmd(['ifconfig', intf, ip + bits, 'up'])
|
||||
self.ips[intf] = ip
|
||||
return result
|
||||
|
||||
def setHostRoute(self, ip, intf):
|
||||
'''Add route to host.
|
||||
|
||||
@param ip IP address as dotted decimal
|
||||
@param intf string, interface name
|
||||
'''
|
||||
return self.cmd('route add -host ' + ip + ' dev ' + intf)
|
||||
|
||||
def setDefaultRoute(self, intf):
|
||||
'''Set the default route to go through intf.
|
||||
|
||||
@param intf string, interface name
|
||||
'''
|
||||
self.cmd('ip route flush')
|
||||
return self.cmd('route add default ' + intf)
|
||||
|
||||
def IP(self):
|
||||
'''Return IP address of first interface'''
|
||||
if len(self.intfs) > 0:
|
||||
return self.ips.get(self.intfs[ 0 ], None)
|
||||
|
||||
def intfIsUp(self):
|
||||
'''Check if one of our interfaces is up.'''
|
||||
return 'UP' in self.cmd('ifconfig ' + self.intfs[0])
|
||||
|
||||
# Other methods
|
||||
def __str__(self):
|
||||
result = self.name + ':'
|
||||
if self.IP():
|
||||
result += ' IP=' + self.IP()
|
||||
result += ' intfs=' + ','.join(self.intfs)
|
||||
result += ' waiting=' + repr(self.waiting)
|
||||
return result
|
||||
|
||||
|
||||
class Host(Node):
|
||||
'''A host is simply a Node.'''
|
||||
pass
|
||||
|
||||
|
||||
class Controller(Node):
|
||||
'''A Controller is a Node that is running (or has execed) an
|
||||
OpenFlow controller.'''
|
||||
|
||||
def __init__(self, name, kernel=True, controller='controller',
|
||||
cargs='-v ptcp:', cdir=None):
|
||||
self.controller = controller
|
||||
self.cargs = cargs
|
||||
self.cdir = cdir
|
||||
Node.__init__(self, name, inNamespace=(not kernel))
|
||||
|
||||
def start(self):
|
||||
'''Start <controller> <args> on controller.
|
||||
|
||||
Log to /tmp/cN.log
|
||||
'''
|
||||
cout = '/tmp/' + self.name + '.log'
|
||||
if self.cdir is not None:
|
||||
self.cmdPrint('cd ' + self.cdir)
|
||||
self.cmdPrint(self.controller + ' ' + self.cargs +
|
||||
' 1> ' + cout + ' 2> ' + cout + ' &')
|
||||
self.execed = False # XXX Until I fix it
|
||||
|
||||
def stop(self):
|
||||
'''Stop controller.'''
|
||||
self.cmd('kill %' + self.controller)
|
||||
self.terminate()
|
||||
|
||||
|
||||
class Switch(Node):
|
||||
'''A Switch is a Node that is running (or has execed)
|
||||
an OpenFlow switch.'''
|
||||
|
||||
def __init__(self, name, datapath = None):
|
||||
'''Init.
|
||||
|
||||
@param name
|
||||
@param datapath string, datapath name
|
||||
'''
|
||||
self.dp = datapath
|
||||
Node.__init__(self, name, inNamespace = (datapath == None))
|
||||
|
||||
def _startUserDatapath(self, controller):
|
||||
'''Start OpenFlow reference user datapath.
|
||||
|
||||
Log to /tmp/sN-{ofd,ofp}.log.
|
||||
|
||||
@param controller Controller object.
|
||||
'''
|
||||
ofdlog = '/tmp/' + self.name + '-ofd.log'
|
||||
ofplog = '/tmp/' + self.name + '-ofp.log'
|
||||
self.cmd('ifconfig lo up')
|
||||
intfs = self.intfs[1:] # 0 is mgmt interface
|
||||
self.cmdPrint('ofdatapath -i ' + ','.join(intfs) +
|
||||
' ptcp: 1> ' + ofdlog + ' 2> ' + ofdlog + ' &')
|
||||
self.cmdPrint('ofprotocol tcp:' + controller.IP() +
|
||||
' tcp:localhost --fail=closed 1> ' + ofplog + ' 2>' +
|
||||
ofplog + ' &')
|
||||
|
||||
def _stopUserDatapath(self):
|
||||
'''Stop OpenFlow reference user datapath.'''
|
||||
self.cmd('kill %ofdatapath')
|
||||
self.cmd('kill %ofprotocol')
|
||||
|
||||
def _startKernelDatapath(self):
|
||||
'''Start up reference kernel datapath.'''
|
||||
ofplog = '/tmp/' + self.name + '-ofp.log'
|
||||
quietRun('ifconfig lo up')
|
||||
# Delete local datapath if it exists;
|
||||
# then create a new one monitoring the given interfaces
|
||||
quietRun('dpctl deldp ' + self.dp)
|
||||
self.cmdPrint('dpctl adddp ' + self.dp)
|
||||
self.cmdPrint('dpctl addif ' + self.dp + ' ' + ' '.join(self.intfs))
|
||||
# Run protocol daemon
|
||||
self.cmdPrint('ofprotocol' +
|
||||
' ' + self.dp + ' tcp:127.0.0.1 ' +
|
||||
' --fail=closed 1> ' + ofplog + ' 2>' + ofplog + ' &')
|
||||
self.execed = False # XXX until I fix it
|
||||
|
||||
def _stopKernelDatapath(self):
|
||||
'''Terminate reference kernel datapath.'''
|
||||
quietRun('dpctl deldp ' + self.dp)
|
||||
# In theory the interfaces should go away after we shut down.
|
||||
# However, this takes time, so we're better off to remove them
|
||||
# explicitly so that we won't get errors if we run before they
|
||||
# have been removed by the kernel. Unfortunately this is very slow.
|
||||
self.cmd('kill %ofprotocol')
|
||||
for intf in self.intfs:
|
||||
quietRun('ip link del ' + intf)
|
||||
lg.info('.')
|
||||
|
||||
def start(self, controller):
|
||||
'''Start datapath.
|
||||
|
||||
@param controller Controller object
|
||||
'''
|
||||
if self.dp is None:
|
||||
self._startUserDatapath(controller)
|
||||
else:
|
||||
self._startKernelDatapath()
|
||||
|
||||
def stop(self):
|
||||
'''Stop datapath.'''
|
||||
if self.dp is None:
|
||||
self._stopUserDatapath()
|
||||
else:
|
||||
self._stopKernelDatapath()
|
||||
|
||||
def sendCmd(self, cmd):
|
||||
'''Send command to Node.
|
||||
|
||||
@param cmd string
|
||||
'''
|
||||
if not self.execed:
|
||||
return Node.sendCmd(self, cmd)
|
||||
else:
|
||||
lg.error('*** Error: %s has execed and cannot accept commands' %
|
||||
self.name)
|
||||
|
||||
def monitor(self):
|
||||
'''Monitor node.'''
|
||||
if not self.execed:
|
||||
return Node.monitor(self)
|
||||
else:
|
||||
return True, ''
|
||||
Reference in New Issue
Block a user