Rename third_party/webpagereplay to third_party/web-page-replay

telemetry/third_party/webpagereplay/trafficshaper.py

-#!/usr/bin/env python
-# Copyright 2010 Google Inc. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import logging
-import platformsettings
-import re
-
-
-# Mac has broken bandwitdh parsing, so double check the values.
-# On Mac OS X 10.6, "KBit/s" actually uses "KByte/s".
-BANDWIDTH_PATTERN = r'0|\d+[KM]?(bit|Byte)/s'
-
-
-class TrafficShaperException(Exception):
-  pass
-
-
-class BandwidthValueError(TrafficShaperException):
-  def __init__(self, value):  # pylint: disable=super-init-not-called
-    self.value = value
-
-  def __str__(self):
-    return 'Value, "%s", does not match regex: %s' % (
-        self.value, BANDWIDTH_PATTERN)
-
-
-class TrafficShaper(object):
-  """Manages network traffic shaping."""
-
-  # Pick webpagetest-compatible values (details: http://goo.gl/oghTg).
-  _UPLOAD_PIPE = '10'      # Enforces overall upload bandwidth.
-  _UPLOAD_QUEUE = '10'     # Shares upload bandwidth among source ports.
-  _UPLOAD_RULE = '5000'    # Specifies when the upload queue is used.
-  _DOWNLOAD_PIPE = '11'    # Enforces overall download bandwidth.
-  _DOWNLOAD_QUEUE = '11'   # Shares download bandwidth among destination ports.
-  _DOWNLOAD_RULE = '5100'  # Specifies when the download queue is used.
-  _QUEUE_SLOTS = 100       # Number of packets to queue.
-
-  _BANDWIDTH_RE = re.compile(BANDWIDTH_PATTERN)
-
-  def __init__(self,
-               dont_use=None,
-               host='127.0.0.1',
-               ports=None,
-               up_bandwidth='0',
-               down_bandwidth='0',
-               delay_ms='0',
-               packet_loss_rate='0',
-               init_cwnd='0',
-               use_loopback=True):
-    """Start shaping traffic.
-
-    Args:
-      host: a host string (name or IP) for the web proxy.
-      ports: a list of ports to shape traffic on.
-      up_bandwidth: Upload bandwidth
-      down_bandwidth: Download bandwidth
-           Bandwidths measured in [K|M]{bit/s|Byte/s}. '0' means unlimited.
-      delay_ms: Propagation delay in milliseconds. '0' means no delay.
-      packet_loss_rate: Packet loss rate in range [0..1]. '0' means no loss.
-      init_cwnd: the initial cwnd setting. '0' means no change.
-      use_loopback: True iff shaping is done on the loopback (or equiv) adapter.
-    """
-    assert dont_use is None  # Force args to be named.
-    self.host = host
-    self.ports = ports
-    self.up_bandwidth = up_bandwidth
-    self.down_bandwidth = down_bandwidth
-    self.delay_ms = delay_ms
-    self.packet_loss_rate = packet_loss_rate
-    self.init_cwnd = init_cwnd
-    self.use_loopback = use_loopback
-    if not self._BANDWIDTH_RE.match(self.up_bandwidth):
-      raise BandwidthValueError(self.up_bandwidth)
-    if not self._BANDWIDTH_RE.match(self.down_bandwidth):
-      raise BandwidthValueError(self.down_bandwidth)
-    self.is_shaping = False
-
-  def __enter__(self):
-    if self.use_loopback:
-      platformsettings.setup_temporary_loopback_config()
-    if self.init_cwnd != '0':
-      platformsettings.set_temporary_tcp_init_cwnd(self.init_cwnd)
-    try:
-      ipfw_list = platformsettings.ipfw('list')
-      if not ipfw_list.startswith('65535 '):
-        logging.warn('ipfw has existing rules:\n%s', ipfw_list)
-        self._delete_rules(ipfw_list)
-    except Exception:
-      pass
-    if (self.up_bandwidth == '0' and self.down_bandwidth == '0' and
-        self.delay_ms == '0' and self.packet_loss_rate == '0'):
-      logging.info('Skipped shaping traffic.')
-      return
-    if not self.ports:
-      raise TrafficShaperException('No ports on which to shape traffic.')
-
-    ports = ','.join(str(p) for p in self.ports)
-    half_delay_ms = int(self.delay_ms) / 2  # split over up/down links
-
-    try:
-      # Configure upload shaping.
-      platformsettings.ipfw(
-          'pipe', self._UPLOAD_PIPE,
-          'config',
-          'bw', self.up_bandwidth,
-          'delay', half_delay_ms,
-          )
-      platformsettings.ipfw(
-          'queue', self._UPLOAD_QUEUE,
-          'config',
-          'pipe', self._UPLOAD_PIPE,
-          'plr', self.packet_loss_rate,
-          'queue', self._QUEUE_SLOTS,
-          'mask', 'src-port', '0xffff',
-          )
-      platformsettings.ipfw(
-          'add', self._UPLOAD_RULE,
-          'queue', self._UPLOAD_QUEUE,
-          'ip',
-          'from', 'any',
-          'to', self.host,
-          self.use_loopback and 'out' or 'in',
-          'dst-port', ports,
-          )
-      self.is_shaping = True
-
-      # Configure download shaping.
-      platformsettings.ipfw(
-          'pipe', self._DOWNLOAD_PIPE,
-          'config',
-          'bw', self.down_bandwidth,
-          'delay', half_delay_ms,
-          )
-      platformsettings.ipfw(
-          'queue', self._DOWNLOAD_QUEUE,
-          'config',
-          'pipe', self._DOWNLOAD_PIPE,
-          'plr', self.packet_loss_rate,
-          'queue', self._QUEUE_SLOTS,
-          'mask', 'dst-port', '0xffff',
-          )
-      platformsettings.ipfw(
-          'add', self._DOWNLOAD_RULE,
-          'queue', self._DOWNLOAD_QUEUE,
-          'ip',
-          'from', self.host,
-          'to', 'any',
-          'out',
-          'src-port', ports,
-          )
-      logging.info('Started shaping traffic')
-    except Exception:
-      logging.error('Unable to shape traffic.')
-      raise
-
-  def __exit__(self, unused_exc_type, unused_exc_val, unused_exc_tb):
-    if self.is_shaping:
-      try:
-        self._delete_rules()
-        logging.info('Stopped shaping traffic')
-      except Exception:
-        logging.error('Unable to stop shaping traffic.')
-        raise
-
-  def _delete_rules(self, ipfw_list=None):
-    if ipfw_list is None:
-      ipfw_list = platformsettings.ipfw('list')
-    existing_rules = set(
-        r.split()[0].lstrip('0') for r in ipfw_list.splitlines())
-    delete_rules = [r for r in (self._DOWNLOAD_RULE, self._UPLOAD_RULE)
-                    if r in existing_rules]
-    if delete_rules:
-      platformsettings.ipfw('delete', *delete_rules)