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- Checks the OS and runs the appropriate commands for Dummynet (ipfw)

Browse Source 
- Added pipe rule flush handling
- Also fixed a bug preventing any rule settings other than default from being 
  used no matter what preset was chosen
- Fixed some comments.

BUGS=none
TEST= Windows and linux
Review URL: https://webrtc-codereview.appspot.com/1158006

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3639 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
jansson@webrtc.org 2013-03-08 10:50:14 +00:00
parent 971278a962
commit 755e19adfc
2 changed files with 53 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
tools/network_emulator/emulate.py
View File

@ -9,15 +9,16 @@
"""Script for constraining traffic on the local machine."""
import logging
import optparse
import os
import socket
import sys
import config
import network_emulator
_DEFAULT_LOG_LEVEL = logging.INFO
# Default port range to apply network constraints on.
@ -68,7 +69,7 @@ def _parse_args():
'ID Name Receive Send Queue Delay loss \n'
'-- ---- --------- -------- ----- ------- ------\n'
'%s\n' % presets_string))
parser.add_option('-p', '--preset', type='int', default=2,
parser.add_option('-p', '--preset', type='int', default=_DEFAULT_PRESET_ID,
help=('ConnectionConfig configuration, specified by ID. '
'Default: %default'))
parser.add_option('-r', '--receive-bw', type='int',
@ -98,11 +99,11 @@ def _parse_args():
options = parser.parse_args()[0]
# Find preset by ID, if specified:
# Find preset by ID, if specified.
if options.preset and not _PRESETS_DICT.has_key(options.preset):
parser.error('Invalid preset: %s' % options.preset)
# Simple validation of the IP address, if supplied:
# Simple validation of the IP address, if supplied.
if options.target_ip:
try:
socket.inet_aton(options.target_ip)
@ -133,27 +134,21 @@ def _set_logger(verbose):
def _main():
"""Checks arguments, permissions and runs a network emulation."""
if os.name != 'posix':
print >> sys.stderr, 'This script is only supported on Linux and Mac.'
return 1
options = _parse_args()
# Build a configuration object. Override any preset configuration settings if
# a value of a setting was also given as a flag.
connection_config = _PRESETS_DICT[options.preset]
if options.receive_bw:
if options.receive_bw is not _DEFAULT_PRESET.receive_bw_kbps:
connection_config.receive_bw_kbps = options.receive_bw
if options.send_bw:
if options.send_bw is not _DEFAULT_PRESET.send_bw_kbps:
connection_config.send_bw_kbps = options.send_bw
if options.delay:
if options.delay is not _DEFAULT_PRESET.delay_ms:
connection_config.delay_ms = options.delay
if options.packet_loss:
if options.packet_loss is not _DEFAULT_PRESET.packet_loss_percent:
connection_config.packet_loss_percent = options.packet_loss
if options.queue:
if options.queue is not _DEFAULT_PRESET.queue_slots:
connection_config.queue_slots = options.queue
emulator = network_emulator.NetworkEmulator(connection_config,
options.port_range)
try:

75
tools/network_emulator/network_emulator.py
View File

@ -9,6 +9,7 @@
"""Script for constraining traffic on the local machine."""
import ctypes
import logging
import os
import subprocess
@ -88,21 +89,26 @@ class NetworkEmulator(object):
NetworkEmulatorError: If permissions to run Dummynet commands are not
available.
"""
if os.geteuid() != 0:
_run_shell_command(
['sudo', '-n', 'ipfw', '-h'],
msg=('Cannot run \'ipfw\' command. This script must be run as '
'root or have password-less sudo access to this command.'))
try:
if os.getuid() != 0:
raise NetworkEmulatorError('You must run this script with sudo.')
except AttributeError:
@staticmethod
def cleanup():
# AttributeError will be raised on Windows.
if ctypes.windll.shell32.IsUserAnAdmin() == 0:
raise NetworkEmulatorError('You must run this script with administrator'
'privileges.')
def cleanup(self):
"""Stops the network emulation by flushing all Dummynet rules.
Notice that this will flush any rules that may have been created previously
before starting the emulation.
"""
_run_shell_command(['sudo', 'ipfw', '-f', 'flush'],
'Failed to flush Dummynet rules!')
self._run_ipfw_command(['-f', 'flush'],
'Failed to flush Dummynet rules!')
self._run_ipfw_command(['-f', 'pipe', 'flush'],
'Failed to flush Dummynet pipes!')
def _create_dummynet_rule(self, pipe_id, from_address, to_address,
port_range):
@ -121,12 +127,12 @@ class NetworkEmulator(object):
each rule being added.
"""
self._rule_counter += 100
add_part = ['sudo', 'ipfw', 'add', self._rule_counter, 'pipe', pipe_id,
add_part = ['add', self._rule_counter, 'pipe', pipe_id,
'ip', 'from', from_address, 'to', to_address]
_run_shell_command(add_part + ['src-port', '%s-%s' % port_range],
'Failed to add Dummynet src-port rule.')
_run_shell_command(add_part + ['dst-port', '%s-%s' % port_range],
'Failed to add Dummynet dst-port rule.')
self._run_ipfw_command(add_part + ['src-port', '%s-%s' % port_range],
'Failed to add Dummynet src-port rule.')
self._run_ipfw_command(add_part + ['dst-port', '%s-%s' % port_range],
'Failed to add Dummynet dst-port rule.')
return self._rule_counter
def _create_dummynet_pipe(self, bandwidth_kbps, delay_ms, packet_loss_percent,
@ -142,7 +148,7 @@ class NetworkEmulator(object):
The ID of the pipe, starting at 1.
"""
self._pipe_counter += 1
cmd = ['sudo', 'ipfw', 'pipe', self._pipe_counter, 'config',
cmd = ['pipe', self._pipe_counter, 'config',
'bw', str(bandwidth_kbps/8) + 'KByte/s',
'delay', '%sms' % delay_ms,
'plr', (packet_loss_percent/100.0),
@ -150,10 +156,13 @@ class NetworkEmulator(object):
error_message = 'Failed to create Dummynet pipe. '
if sys.platform.startswith('linux'):
error_message += ('Make sure you have loaded the ipfw_mod.ko module to '
'your kernel (sudo insmod /path/to/ipfw_mod.ko)')
_run_shell_command(cmd, error_message)
'your kernel (sudo insmod /path/to/ipfw_mod.ko).')
self._run_ipfw_command(cmd, error_message)
return self._pipe_counter
def _run_ipfw_command(self, command, msg=None):
"""Executes a command and it prefixes the appropriate command for
Windows or Linux/UNIX.
def _run_shell_command(command, msg=None):
"""Executes a command.
@ -162,20 +171,22 @@ def _run_shell_command(command, msg=None):
command: Command list to execute.
msg: Message describing the error in case the command fails.
Returns:
The standard output from running the command.
Raises:
NetworkEmulatorError: If command fails. Message is set by the msg
Raises:
NetworkEmulatorError: If command fails. Message is set by the msg
parameter.
"""
cmd_list = [str(x) for x in command]
cmd = ' '.join(cmd_list)
logging.debug('Running command: %s', cmd)
"""
if sys.platform == 'win32':
ipfw_command = ['ipfw.exe']
else:
ipfw_command = ['sudo', '-n', 'ipfw']
process = subprocess.Popen(cmd_list, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
output, error = process.communicate()
if process.returncode != 0:
raise NetworkEmulatorError(msg, cmd, process.returncode, output, error)
return output.strip()
cmd_list = ipfw_command[:] + [str(x) for x in command]
cmd_string = ' '.join(cmd_list)
logging.debug('Running command: %s', cmd_string)
process = subprocess.Popen(cmd_list, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
output, error = process.communicate()
if process.returncode != 0:
raise NetworkEmulatorError(msg, cmd_string, process.returncode, output,
error)
return output.strip()