2.3.0d6

Use incremental utf-8 decoder for buffered reading

INSTALL

@@ -2,7 +2,7 @@
 Mininet Installation/Configuration Notes
 ----------------------------------------
 
-Mininet 2.3.0d5
+Mininet 2.3.0d6
 ---
 
 The supported installation methods for Mininet are 1) using a

LICENSE

@@ -1,4 +1,4 @@
-Mininet 2.3.0d5 License
+Mininet 2.3.0d6 License
 
 Copyright (c) 2013-2019 Open Networking Laboratory
 Copyright (c) 2009-2012 Bob Lantz and The Board of Trustees of

README.md

@@ -2,7 +2,7 @@ Mininet: Rapid Prototyping for Software Defined Networks
 ========================================================
 *The best way to emulate almost any network on your laptop!*
 
-Mininet 2.3.0d5
+Mininet 2.3.0d6
 
 [![Build Status][1]](https://travis-ci.org/mininet/mininet)
 

bin/mn

@@ -388,6 +388,10 @@ class MininetRunner( object ):
                   listenPort=opts.listenport )
 
         if opts.ensure_value( 'nat', False ):
+            with open( '/etc/resolv.conf' ) as f:
+                if 'nameserver 127.' in f.read():
+                    warn( '*** Warning: loopback address in /etc/resolv.conf '
+                          'may break host DNS over NAT\n')
             mn.addNAT( *opts.nat_args, **opts.nat_kwargs ).configDefault()
 
         # --custom files can set CLI or change mininet.cli.CLI

mininet/link.py

@@ -295,7 +295,7 @@ class TCIntf( Intf ):
             netemargs = '%s%s%s%s' % (
                 'delay %s ' % delay if delay is not None else '',
                 '%s ' % jitter if jitter is not None else '',
-                'loss %.5f ' % loss if loss is not None else '',
+                'loss %.5f ' % loss if (loss is not None and loss > 0) else '',
                 'limit %d' % max_queue_size if max_queue_size is not None
                 else '' )
             if netemargs:

mininet/net.py

@@ -108,7 +108,7 @@ from mininet.util import ( quietRun, fixLimits, numCores, ensureRoot,
 from mininet.term import cleanUpScreens, makeTerms
 
 # Mininet version: should be consistent with README and LICENSE
-VERSION = "2.3.0d5"
+VERSION = "2.3.0d6"
 
 class Mininet( object ):
     "Network emulation with hosts spawned in network namespaces."

mininet/node.py

@@ -63,7 +63,7 @@ from time import sleep
 from mininet.log import info, error, warn, debug
 from mininet.util import ( quietRun, errRun, errFail, moveIntf, isShellBuiltin,
                            numCores, retry, mountCgroups, BaseString, decode,
-                           encode, Python3 )
+                           encode, getincrementaldecoder, Python3, which )
 from mininet.moduledeps import moduleDeps, pathCheck, TUN
 from mininet.link import Link, Intf, TCIntf, OVSIntf
 from re import findall
@@ -106,6 +106,9 @@ class Node( object ):
         self.waiting = False
         self.readbuf = ''
 
+        # Incremental decoder for buffered reading
+        self.decoder = getincrementaldecoder()
+
         # Start command interpreter shell
         self.master, self.slave = None, None  # pylint
         self.startShell()
@@ -229,19 +232,19 @@ class Node( object ):
 
     # Subshell I/O, commands and control
 
-    def read( self, maxbytes=1024 ):
+    def read( self, size=1024 ):
         """Buffered read from node, potentially blocking.
-           maxbytes: maximum number of bytes to return"""
+           size: maximum number of characters to return"""
         count = len( self.readbuf )
-        if count < maxbytes:
-            data = decode( os.read( self.stdout.fileno(), maxbytes - count ) )
-            self.readbuf += data
-        if maxbytes >= len( self.readbuf ):
+        if count < size:
+            data = os.read( self.stdout.fileno(), size - count )
+            self.readbuf += self.decoder.decode( data )
+        if size >= len( self.readbuf ):
             result = self.readbuf
             self.readbuf = ''
         else:
-            result = self.readbuf[ :maxbytes ]
-            self.readbuf = self.readbuf[ maxbytes: ]
+            result = self.readbuf[ :size ]
+            self.readbuf = self.readbuf[ size: ]
         return result
 
     def readline( self ):
@@ -1447,7 +1450,7 @@ class Controller( Node ):
     @classmethod
     def isAvailable( cls ):
         "Is controller available?"
-        return quietRun( 'which controller' )
+        return which( 'controller' )
 
 
 class OVSController( Controller ):
@@ -1459,9 +1462,9 @@ class OVSController( Controller ):
 
     @classmethod
     def isAvailable( cls ):
-        return ( quietRun( 'which ovs-controller' ) or
-                 quietRun( 'which test-controller' ) or
-                 quietRun( 'which ovs-testcontroller' ) ).strip()
+        return (which( 'ovs-controller' ) or
+                which( 'test-controller' ) or
+                which( 'ovs-testcontroller' ))
 
 class NOX( Controller ):
     "Controller to run a NOX application."

mininet/util.py

@@ -13,23 +13,48 @@ from os import O_NONBLOCK
 import os
 from functools import partial
 import sys
+import codecs
 
 # Python 2/3 compatibility
+
 Python3 = sys.version_info[0] == 3
 BaseString = str if Python3 else getattr( str, '__base__' )
 Encoding = 'utf-8' if Python3 else None
-def decode( s ):
-    "Decode a byte string if needed for Python 3"
-    return s.decode( Encoding ) if Python3 else s
-def encode( s ):
-    "Encode a byte string if needed for Python 3"
-    return s.encode( Encoding ) if Python3 else s
+class NullCodec( object ):
+    "Null codec for Python 2"
+    @staticmethod
+    def decode( buf ):
+        "Null decode"
+        return buf
+
+    @staticmethod
+    def encode( buf ):
+        "Null encode"
+        return buf
+
+
+if Python3:
+    def decode( buf ):
+        "Decode buffer for Python 3"
+        return buf.decode( Encoding )
+
+    def encode( buf ):
+        "Encode buffer for Python 3"
+        return buf.encode( Encoding )
+    getincrementaldecoder = codecs.getincrementaldecoder( Encoding )
+else:
+    decode, encode = NullCodec.decode, NullCodec.encode
+
+    def getincrementaldecoder():
+        "Return null codec for Python 2"
+        return NullCodec
+
 try:
     # pylint: disable=import-error
     oldpexpect = None
     import pexpect as oldpexpect
-    # pylint: enable=import-error
 
+    # pylint: enable=import-error
     class Pexpect( object ):
         "Custom pexpect that is compatible with str"
         @staticmethod
@@ -119,20 +144,21 @@ def errRun( *cmd, **kwargs ):
     out, err = '', ''
     poller = poll()
     poller.register( popen.stdout, POLLIN )
-    fdtofile = { popen.stdout.fileno(): popen.stdout }
+    fdToFile = { popen.stdout.fileno(): popen.stdout }
+    fdToDecoder = { popen.stdout.fileno(): getincrementaldecoder() }
     outDone, errDone = False, True
     if popen.stderr:
-        fdtofile[ popen.stderr.fileno() ] = popen.stderr
+        fdToFile[ popen.stderr.fileno() ] = popen.stderr
+        fdToDecoder[ popen.stderr.fileno() ] = getincrementaldecoder()
         poller.register( popen.stderr, POLLIN )
         errDone = False
     while not outDone or not errDone:
         readable = poller.poll()
         for fd, event in readable:
-            f = fdtofile[ fd ]
+            f = fdToFile[ fd ]
+            decoder = fdToDecoder[ fd ]
             if event & POLLIN:
-                data = f.read( 1024 )
-                if Python3:
-                    data = data.decode( Encoding )
+                data = decoder.decode( f.read( 1024 ) )
                 if echo:
                     output( data )
                 if f == popen.stdout:
@@ -171,19 +197,26 @@ def quietRun( cmd, **kwargs ):
     "Run a command and return merged stdout and stderr"
     return errRun( cmd, stderr=STDOUT, **kwargs )[ 0 ]
 
+def which(cmd, **kwargs ):
+    "Run a command and return merged stdout and stderr"
+    out, _, ret = errRun( ["which", cmd], stderr=STDOUT, **kwargs )
+    return out.rstrip() if ret == 0 else None
+
 # pylint: enable=maybe-no-member
 
 def isShellBuiltin( cmd ):
     "Return True if cmd is a bash builtin."
     if isShellBuiltin.builtIns is None:
-        isShellBuiltin.builtIns = quietRun( 'bash -c enable' )
+        isShellBuiltin.builtIns = set(quietRun( 'bash -c enable' ).split())
     space = cmd.find( ' ' )
     if space > 0:
         cmd = cmd[ :space]
     return cmd in isShellBuiltin.builtIns
 
+
 isShellBuiltin.builtIns = None
 
+
 # Interface management
 #
 # Interfaces are managed as strings which are simply the
@@ -370,7 +403,7 @@ def netParse( ipstr ):
     if '/' in ipstr:
         ip, pf = ipstr.split( '/' )
         prefixLen = int( pf )
-    #if no prefix is specified, set the prefix to 24
+    # if no prefix is specified, set the prefix to 24
     else:
         ip = ipstr
         prefixLen = 24
@@ -413,9 +446,11 @@ def pmonitor(popens, timeoutms=500, readline=True,
        terminates: when all EOFs received"""
     poller = poll()
     fdToHost = {}
+    fdToDecoder = {}
     for host, popen in popens.items():
         fd = popen.stdout.fileno()
         fdToHost[ fd ] = host
+        fdToDecoder[ fd ] = getincrementaldecoder()
         poller.register( fd, POLLIN | POLLHUP )
         flags = fcntl( fd, F_GETFL )
         fcntl( fd, F_SETFL, flags | O_NONBLOCK )
@@ -424,13 +459,14 @@ def pmonitor(popens, timeoutms=500, readline=True,
         if fds:
             for fd, event in fds:
                 host = fdToHost[ fd ]
+                decoder = fdToDecoder[ fd ]
                 popen = popens[ host ]
                 if event & POLLIN or event & POLLHUP:
                     while True:
                         try:
                             f = popen.stdout
-                            line = decode( f.readline() if readline
-                                           else f.read( readmax ) )
+                            line = decoder.decode( f.readline() if readline
+                                                   else f.read( readmax ) )
                         except IOError:
                             line = ''
                         if line == '':
@@ -445,19 +481,19 @@ def pmonitor(popens, timeoutms=500, readline=True,
 # Other stuff we use
 def sysctlTestAndSet( name, limit ):
     "Helper function to set sysctl limits"
-    #convert non-directory names into directory names
+    # convert non-directory names into directory names
     if '/' not in name:
         name = '/proc/sys/' + name.replace( '.', '/' )
-    #read limit
+    # read limit
     with open( name, 'r' ) as readFile:
         oldLimit = readFile.readline()
         if isinstance( limit, int ):
-            #compare integer limits before overriding
+            # compare integer limits before overriding
             if int( oldLimit ) < limit:
                 with open( name, 'w' ) as writeFile:
                     writeFile.write( "%d" % limit )
         else:
-            #overwrite non-integer limits
+            # overwrite non-integer limits
             with open( name, 'w' ) as writeFile:
                 writeFile.write( limit )
 
@@ -474,21 +510,21 @@ def fixLimits():
     try:
         rlimitTestAndSet( RLIMIT_NPROC, 8192 )
         rlimitTestAndSet( RLIMIT_NOFILE, 16384 )
-        #Increase open file limit
+        # Increase open file limit
         sysctlTestAndSet( 'fs.file-max', 10000 )
-        #Increase network buffer space
+        # Increase network buffer space
         sysctlTestAndSet( 'net.core.wmem_max', 16777216 )
         sysctlTestAndSet( 'net.core.rmem_max', 16777216 )
         sysctlTestAndSet( 'net.ipv4.tcp_rmem', '10240 87380 16777216' )
         sysctlTestAndSet( 'net.ipv4.tcp_wmem', '10240 87380 16777216' )
         sysctlTestAndSet( 'net.core.netdev_max_backlog', 5000 )
-        #Increase arp cache size
+        # Increase arp cache size
         sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh1', 4096 )
         sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh2', 8192 )
         sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh3', 16384 )
-        #Increase routing table size
+        # Increase routing table size
         sysctlTestAndSet( 'net.ipv4.route.max_size', 32768 )
-        #Increase number of PTYs for nodes
+        # Increase number of PTYs for nodes
         sysctlTestAndSet( 'kernel.pty.max', 20000 )
     # pylint: disable=broad-except
     except Exception:

util/install.sh

@@ -409,7 +409,7 @@ function ovs {
         # Switch can run on its own, but
         # Mininet should control the controller
         # This appears to only be an issue on Ubuntu/Debian
-        if sudo service $OVSC stop; then
+        if sudo service $OVSC stop 2>/dev/null; then
             echo "Stopped running controller"
         fi
         if [ -e /etc/init.d/$OVSC ]; then