| #!/usr/bin/env python |
| # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. |
| # |
| # Use of this source code is governed by a BSD-style license |
| # that can be found in the LICENSE file in the root of the source |
| # tree. An additional intellectual property rights grant can be found |
| # in the file PATENTS. All contributing project authors may |
| # be found in the AUTHORS file in the root of the source tree. |
| |
| """Script for constraining traffic on the local machine.""" |
| |
| |
| import logging |
| import optparse |
| import socket |
| import sys |
| |
| import config |
| import network_emulator |
| |
| |
| _DEFAULT_LOG_LEVEL = logging.INFO |
| |
| # Default port range to apply network constraints on. |
| _DEFAULT_PORT_RANGE = (32768, 65535) |
| |
| # The numbers below are gathered from Google stats from the presets of the Apple |
| # developer tool called Network Link Conditioner. |
| _PRESETS = [ |
| config.ConnectionConfig(1, 'Generic, Bad', 95, 95, 250, 2, 100), |
| config.ConnectionConfig(2, 'Generic, Average', 375, 375, 145, 0.1, 100), |
| config.ConnectionConfig(3, 'Generic, Good', 1000, 1000, 35, 0, 100), |
| config.ConnectionConfig(4, '3G, Average Case', 780, 330, 100, 0, 100), |
| config.ConnectionConfig(5, '3G, Good', 850, 420, 90, 0, 100), |
| config.ConnectionConfig(6, '3G, Lossy Network', 780, 330, 100, 1, 100), |
| config.ConnectionConfig(7, 'Cable Modem', 6000, 1000, 2, 0, 10), |
| config.ConnectionConfig(8, 'DSL', 2000, 256, 5, 0, 10), |
| config.ConnectionConfig(9, 'Edge, Average Case', 240, 200, 400, 0, 100), |
| config.ConnectionConfig(10, 'Edge, Good', 250, 200, 350, 0, 100), |
| config.ConnectionConfig(11, 'Edge, Lossy Network', 240, 200, 400, 1, 100), |
| config.ConnectionConfig(12, 'Wifi, Average Case', 40000, 33000, 1, 0, 100), |
| config.ConnectionConfig(13, 'Wifi, Good', 45000, 40000, 1, 0, 100), |
| config.ConnectionConfig(14, 'Wifi, Lossy', 40000, 33000, 1, 0, 100), |
| ] |
| _PRESETS_DICT = dict((p.num, p) for p in _PRESETS) |
| |
| _DEFAULT_PRESET_ID = 2 |
| _DEFAULT_PRESET = _PRESETS_DICT[_DEFAULT_PRESET_ID] |
| |
| |
| class NonStrippingEpilogOptionParser(optparse.OptionParser): |
| """Custom parser to let us show the epilog without weird line breaking.""" |
| |
| def format_epilog(self, formatter): |
| return self.epilog |
| |
| |
| def _get_external_ip(): |
| """Finds out the machine's external IP by connecting to google.com.""" |
| external_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) |
| external_socket.connect(('google.com', 80)) |
| return external_socket.getsockname()[0] |
| |
| |
| def _parse_args(): |
| """Define and parse the command-line arguments.""" |
| presets_string = '\n'.join(str(p) for p in _PRESETS) |
| parser = NonStrippingEpilogOptionParser(epilog=( |
| '\nAvailable presets:\n' |
| ' Bandwidth (kbps) Packet\n' |
| 'ID Name Receive Send Queue Delay loss \n' |
| '-- ---- --------- -------- ----- ------- ------\n' |
| '%s\n' % presets_string)) |
| 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', |
| default=_DEFAULT_PRESET.receive_bw_kbps, |
| help=('Receive bandwidth in kilobit/s. Default: %default')) |
| parser.add_option('-s', '--send-bw', type='int', |
| default=_DEFAULT_PRESET.send_bw_kbps, |
| help=('Send bandwidth in kilobit/s. Default: %default')) |
| parser.add_option('-d', '--delay', type='int', |
| default=_DEFAULT_PRESET.delay_ms, |
| help=('Delay in ms. Default: %default')) |
| parser.add_option('-l', '--packet-loss', type='float', |
| default=_DEFAULT_PRESET.packet_loss_percent, |
| help=('Packet loss in %. Default: %default')) |
| parser.add_option('-q', '--queue', type='int', |
| default=_DEFAULT_PRESET.queue_slots, |
| help=('Queue size as number of slots. Default: %default')) |
| parser.add_option('--port-range', default='%s,%s' % _DEFAULT_PORT_RANGE, |
| help=('Range of ports for constrained network. Specify as ' |
| 'two comma separated integers. Default: %default')) |
| parser.add_option('--target-ip', default=None, |
| help=('The interface IP address to apply the rules for. ' |
| 'Default: the external facing interface IP address.')) |
| parser.add_option('-v', '--verbose', action='store_true', default=False, |
| help=('Turn on verbose output. Will print all \'ipfw\' ' |
| 'commands that are executed.')) |
| |
| options = parser.parse_args()[0] |
| |
| # 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. |
| if options.target_ip: |
| try: |
| socket.inet_aton(options.target_ip) |
| except socket.error: |
| parser.error('Invalid IP address specified: %s' % options.target_ip) |
| |
| # Convert port range into the desired tuple format. |
| try: |
| if isinstance(options.port_range, str): |
| options.port_range = tuple(int(port) for port in |
| options.port_range.split(',')) |
| if len(options.port_range) != 2: |
| parser.error('Invalid port range specified, please specify two ' |
| 'integers separated by a comma.') |
| except ValueError: |
| parser.error('Invalid port range specified.') |
| |
| _set_logger(options.verbose) |
| return options |
| |
| |
| def _set_logger(verbose): |
| """Setup logging.""" |
| log_level = _DEFAULT_LOG_LEVEL |
| if verbose: |
| log_level = logging.DEBUG |
| logging.basicConfig(level=log_level, format='%(message)s') |
| |
| |
| def _main(): |
| 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 is not _DEFAULT_PRESET.receive_bw_kbps: |
| connection_config.receive_bw_kbps = options.receive_bw |
| if options.send_bw is not _DEFAULT_PRESET.send_bw_kbps: |
| connection_config.send_bw_kbps = options.send_bw |
| if options.delay is not _DEFAULT_PRESET.delay_ms: |
| connection_config.delay_ms = options.delay |
| if options.packet_loss is not _DEFAULT_PRESET.packet_loss_percent: |
| connection_config.packet_loss_percent = options.packet_loss |
| 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: |
| emulator.check_permissions() |
| except network_emulator.NetworkEmulatorError as e: |
| logging.error('Error: %s\n\nCause: %s', e.fail_msg, e.error) |
| return -1 |
| |
| if not options.target_ip: |
| external_ip = _get_external_ip() |
| else: |
| external_ip = options.target_ip |
| |
| logging.info('Constraining traffic to/from IP: %s', external_ip) |
| try: |
| emulator.emulate(external_ip) |
| logging.info('Started network emulation with the following configuration:\n' |
| ' Receive bandwidth: %s kbps (%s kB/s)\n' |
| ' Send bandwidth : %s kbps (%s kB/s)\n' |
| ' Delay : %s ms\n' |
| ' Packet loss : %s %%\n' |
| ' Queue slots : %s', |
| connection_config.receive_bw_kbps, |
| connection_config.receive_bw_kbps/8, |
| connection_config.send_bw_kbps, |
| connection_config.send_bw_kbps/8, |
| connection_config.delay_ms, |
| connection_config.packet_loss_percent, |
| connection_config.queue_slots) |
| logging.info('Affected traffic: IP traffic on ports %s-%s', |
| options.port_range[0], options.port_range[1]) |
| raw_input('Press Enter to abort Network Emulation...') |
| logging.info('Flushing all Dummynet rules...') |
| network_emulator.cleanup() |
| logging.info('Completed Network Emulation.') |
| return 0 |
| except network_emulator.NetworkEmulatorError as e: |
| logging.error('Error: %s\n\nCause: %s', e.fail_msg, e.error) |
| return -2 |
| |
| if __name__ == '__main__': |
| sys.exit(_main()) |
