[Cronet] Resurrect Android USB reverse tethering

components/cronet/android/test/javaperftests/android_rndis_forwarder.py

Index: components/cronet/android/test/javaperftests/android_rndis_forwarder.py
diff --git a/components/cronet/android/test/javaperftests/android_rndis_forwarder.py b/components/cronet/android/test/javaperftests/android_rndis_forwarder.py
new file mode 100644
index 0000000000000000000000000000000000000000..bec2ab14b05d7f468086ecef0e0cf7bca02fc254
--- /dev/null
+++ b/components/cronet/android/test/javaperftests/android_rndis_forwarder.py
@@ -0,0 +1,477 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import atexit
+import os
+import re
+import socket
+import struct
+import subprocess
+
+from telemetry.core import platform
+from telemetry.internal.platform import android_device
+
+from devil.android import device_errors
+from devil.android import device_utils
+
+class AndroidRndisForwarder(object):
+  """Forwards traffic using RNDIS. Assumes the device has root access."""
+
+  def __init__(self, device, rndis_configurator):
+    self._device = device
+    self._rndis_configurator = rndis_configurator
+    self._device_iface = rndis_configurator.device_iface
+    self._host_ip = rndis_configurator.host_ip
+    self._original_dns = None, None, None
+    self._RedirectPorts()
+    self._OverrideDns()
+    self._OverrideDefaultGateway()
+    # Need to override routing policy again since call to setifdns
+    # sometimes resets policy table
+    self._rndis_configurator.OverrideRoutingPolicy()
+    atexit.register(self.Close)
+    # TODO(tonyg): Verify that each port can connect to host.
+
+  @property
+  def host_ip(self):
+    return self._host_ip
+
+  def Close(self):
+    #if self._forwarding:
+    #  self._rndis_configurator.RestoreRoutingPolicy()
+    #  self._SetDns(*self._original_dns)
+    #  self._RestoreDefaultGateway()
+    #super(AndroidRndisForwarder, self).Close()
+    pass
+
+  def _RedirectPorts(self):
+    """Sets the local to remote pair mappings to use for RNDIS."""
+    # Flush any old nat rules.
+    self._device.RunShellCommand('iptables -F -t nat')
+
+  def _OverrideDns(self):
+    """Overrides DNS on device to point at the host."""
+    self._original_dns = self._GetCurrentDns()
+    self._SetDns(self._device_iface, self.host_ip, self.host_ip)
+
+  def _SetDns(self, iface, dns1, dns2):
+    """Overrides device's DNS configuration.
+
+    Args:
+      iface: name of the network interface to make default
+      dns1, dns2: nameserver IP addresses
+    """
+    if not iface:
+      return  # If there is no route, then nobody cares about DNS.
+    # DNS proxy in older versions of Android is configured via properties.
+    # TODO(szym): run via su -c if necessary.
+    self._device.SetProp('net.dns1', dns1)
+    self._device.SetProp('net.dns2', dns2)
+    dnschange = self._device.GetProp('net.dnschange')
+    if dnschange:
+      self._device.SetProp('net.dnschange', str(int(dnschange) + 1))
+    # Since commit 8b47b3601f82f299bb8c135af0639b72b67230e6 to frameworks/base
+    # the net.dns1 properties have been replaced with explicit commands for netd
+    self._device.RunShellCommand('netd resolver setifdns %s %s %s' %
+                                 (iface, dns1, dns2))
+    # TODO(szym): if we know the package UID, we could setifaceforuidrange
+    self._device.RunShellCommand('netd resolver setdefaultif %s' % iface)
+
+  def _GetCurrentDns(self):
+    """Returns current gateway, dns1, and dns2."""
+    routes = self._device.RunShellCommand('cat /proc/net/route')[1:]
+    routes = [route.split() for route in routes]
+    default_routes = [route[0] for route in routes if route[1] == '00000000']
+    return (
+      default_routes[0] if default_routes else None,
+      self._device.GetProp('net.dns1'),
+      self._device.GetProp('net.dns2'),
+    )
+
+  def _OverrideDefaultGateway(self):
+    """Force traffic to go through RNDIS interface.
+
+    Override any default gateway route. Without this traffic may go through
+    the wrong interface.
+
+    This introduces the risk that _RestoreDefaultGateway() is not called
+    (e.g. Telemetry crashes). A power cycle or "adb reboot" is a simple
+    workaround around in that case.
+    """
+    self._device.RunShellCommand('route add default gw %s dev %s' %
+                                 (self.host_ip, self._device_iface))
+
+  def _RestoreDefaultGateway(self):
+    self._device.RunShellCommand('netcfg %s down' % self._device_iface)
+
+
+class AndroidRndisConfigurator(object):
+  """Configures a linux host to connect to an android device via RNDIS.
+
+  Note that we intentionally leave RNDIS running on the device. This is
+  because the setup is slow and potentially flaky and leaving it running
+  doesn't seem to interfere with any other developer or bot use-cases.
+  """
+
+  _RNDIS_DEVICE = '/sys/class/android_usb/android0'
+  _NETWORK_INTERFACES = '/etc/network/interfaces'
+  _INTERFACES_INCLUDE = 'source /etc/network/interfaces.d/*.conf'
+  _TELEMETRY_INTERFACE_FILE = '/etc/network/interfaces.d/telemetry-{}.conf'
+
+  def __init__(self, device):
+    self._device = device
+
+    try:
+      self._device.EnableRoot()
+    except device_errors.CommandFailedError:
+      logging.error('RNDIS forwarding requires a rooted device.')
+      raise
+
+    self._device_ip = None
+    self._host_iface = None
+    self._host_ip = None
+    self.device_iface = None
+
+    if platform.GetHostPlatform().GetOSName() == 'mac':
+      self._InstallHorndis(platform.GetHostPlatform().GetArchName())
+
+    assert self._IsRndisSupported(), 'Device does not support RNDIS.'
+    self._CheckConfigureNetwork()
+
+  @property
+  def host_ip(self):
+    return self._host_ip
+
+  def _IsRndisSupported(self):
+    """Checks that the device has RNDIS support in the kernel."""
+    return self._device.FileExists('%s/f_rndis/device' % self._RNDIS_DEVICE)
+
+  def _FindDeviceRndisInterface(self):
+    """Returns the name of the RNDIS network interface if present."""
+    config = self._device.RunShellCommand('ip -o link show')
+    interfaces = [line.split(':')[1].strip() for line in config]
+    candidates = [iface for iface in interfaces if re.match('rndis|usb', iface)]
+    if candidates:
+      candidates.sort()
+      if len(candidates) == 2 and candidates[0].startswith('rndis') and \
+          candidates[1].startswith('usb'):
+        return candidates[0]
+      assert len(candidates) == 1, 'Found more than one rndis device!'
+      return candidates[0]
+
+  def _EnumerateHostInterfaces(self):
+    host_platform = platform.GetHostPlatform().GetOSName()
+    if host_platform == 'linux':
+      return subprocess.check_output(['ip', 'addr']).splitlines()
+    if host_platform == 'mac':
+      return subprocess.check_output(['ifconfig']).splitlines()
+    raise NotImplementedError('Platform %s not supported!' % host_platform)
+
+  def _FindHostRndisInterface(self):
+    """Returns the name of the host-side network interface."""
+    interface_list = self._EnumerateHostInterfaces()
+    ether_address = self._device.ReadFile(
+        '%s/f_rndis/ethaddr' % self._RNDIS_DEVICE,
+        as_root=True, force_pull=True).strip()
+    interface_name = None
+    for line in interface_list:
+      if not line.startswith((' ', '\t')):
+        interface_name = line.split(':')[-2].strip()
+      elif ether_address in line:
+        return interface_name
+
+  def _WriteProtectedFile(self, file_path, contents):
+    subprocess.check_call(
+        ['/usr/bin/sudo', 'bash', '-c',
+         'echo -e "%s" > %s' % (contents, file_path)])
+
+  def _LoadInstalledHoRNDIS(self):
+    """Attempt to load HoRNDIS if installed.
+    If kext could not be loaded or if HoRNDIS is not installed, return False.
+    """
+    if not os.path.isdir('/System/Library/Extensions/HoRNDIS.kext'):
+      logging.info('HoRNDIS not present on system.')
+      return False
+
+    def HoRNDISLoaded():
+      return 'HoRNDIS' in subprocess.check_output(['kextstat'])
+
+    if HoRNDISLoaded():
+      return True
+
+    logging.info('HoRNDIS installed but not running, trying to load manually.')
+    subprocess.check_call(
+        ['/usr/bin/sudo', 'kextload', '-b', 'com.joshuawise.kexts.HoRNDIS'])
+
+    return HoRNDISLoaded()
+
+  def _InstallHorndis(self, arch_name):
+    if self._LoadInstalledHoRNDIS():
+      logging.info('HoRNDIS kext loaded successfully.')
+      return
+    logging.info('Installing HoRNDIS...')
+    pkg_path = binary_manager.FetchPath('horndis', arch_name, 'mac')
+    subprocess.check_call(
+        ['/usr/bin/sudo', 'installer', '-pkg', pkg_path, '-target', '/'])
+
+  def _DisableRndis(self):
+    try:
+      self._device.SetProp('sys.usb.config', 'adb')
+    except device_errors.AdbCommandFailedError:
+      # Ignore exception due to USB connection being reset.
+      pass
+    self._device.WaitUntilFullyBooted()
+
+  def _EnableRndis(self):
+    """Enables the RNDIS network interface."""
+    script_prefix = '/data/local/tmp/rndis'
+    # This could be accomplished via "svc usb setFunction rndis" but only on
+    # devices which have the "USB tethering" feature.
+    # Also, on some devices, it's necessary to go through "none" function.
+    script = """
+trap '' HUP
+trap '' TERM
+trap '' PIPE
+
+function manual_config() {
+  echo %(functions)s > %(dev)s/functions
+  echo 224 > %(dev)s/bDeviceClass
+  echo 1 > %(dev)s/enable
+  start adbd
+  setprop sys.usb.state %(functions)s
+}
+
+# This function kills adb transport, so it has to be run "detached".
+function doit() {
+  setprop sys.usb.config none
+  while [ `getprop sys.usb.state` != "none" ]; do
+    sleep 1
+  done
+  manual_config
+  # For some combinations of devices and host kernels, adb won't work unless the
+  # interface is up, but if we bring it up immediately, it will break adb.
+  #sleep 1
+  #ifconfig rndis0 192.168.123.2 netmask 255.255.255.0 up
+  echo DONE >> %(prefix)s.log
+}
+
+doit &
+    """ % {'dev': self._RNDIS_DEVICE, 'functions': 'rndis,adb',
+           'prefix': script_prefix}
+    self._device.WriteFile('%s.sh' % script_prefix, script)
+    # TODO(szym): run via su -c if necessary.
+    self._device.RunShellCommand('rm %s.log' % script_prefix)
+    self._device.RunShellCommand('. %s.sh' % script_prefix)
+    self._device.WaitUntilFullyBooted()
+    result = self._device.ReadFile('%s.log' % script_prefix).splitlines()
+    assert any('DONE' in line for line in result), 'RNDIS script did not run!'
+
+  def _CheckEnableRndis(self, force):
+    """Enables the RNDIS network interface, retrying if necessary.
+    Args:
+      force: Disable RNDIS first, even if it appears already enabled.
+    Returns:
+      device_iface: RNDIS interface name on the device
+      host_iface: corresponding interface name on the host
+    """
+    for _ in range(3):
+      if not force:
+        device_iface = self._FindDeviceRndisInterface()
+        if device_iface:
+          host_iface = self._FindHostRndisInterface()
+          if host_iface:
+            return device_iface, host_iface
+      self._DisableRndis()
+      self._EnableRndis()
+      force = False
+    raise Exception('Could not enable RNDIS, giving up.')
+
+  def _Ip2Long(self, addr):
+    return struct.unpack('!L', socket.inet_aton(addr))[0]
+
+  def _IpPrefix2AddressMask(self, addr):
+    def _Length2Mask(length):
+      return 0xFFFFFFFF & ~((1 << (32 - length)) - 1)
+
+    addr, masklen = addr.split('/')
+    return self._Ip2Long(addr), _Length2Mask(int(masklen))
+
+  def _GetHostAddresses(self, iface):
+    """Returns the IP addresses on host's interfaces, breaking out |iface|."""
+    interface_list = self._EnumerateHostInterfaces()
+    addresses = []
+    iface_address = None
+    found_iface = False
+    for line in interface_list:
+      if not line.startswith((' ', '\t')):
+        found_iface = iface in line
+      match = re.search(r'(?<=inet )\S+', line)
+      if match:
+        address = match.group(0)
+        if '/' in address:
+          address = self._IpPrefix2AddressMask(address)
+        else:
+          match = re.search(r'(?<=netmask )\S+', line)
+          address = self._Ip2Long(address), int(match.group(0), 16)
+        if found_iface:
+          assert not iface_address, (
+            'Found %s twice when parsing host interfaces.' % iface)
+          iface_address = address
+        else:
+          addresses.append(address)
+    return addresses, iface_address
+
+  def _GetDeviceAddresses(self, excluded_iface):
+    """Returns the IP addresses on all connected devices.
+    Excludes interface |excluded_iface| on the selected device.
+    """
+    my_device = str(self._device)
+    addresses = []
+    for device_serial in android_device.GetDeviceSerials(None):
+      try:
+        device = device_utils.DeviceUtils(device_serial)
+        if device_serial == my_device:
+          excluded = excluded_iface
+        else:
+          excluded = 'no interfaces excluded on other devices'
+        addresses += [line.split()[3]
+                      for line in device.RunShellCommand('ip -o -4 addr')
+                      if excluded not in line]
+      except device_errors.CommandFailedError:
+        logging.warning('Unable to determine IP addresses for %s',
+                        device_serial)
+    return addresses
+
+  def _ConfigureNetwork(self, device_iface, host_iface):
+    """Configures the |device_iface| to be on the same network as |host_iface|.
+    """
+    def _Long2Ip(value):
+      return socket.inet_ntoa(struct.pack('!L', value))
+
+    def _IsNetworkUnique(network, addresses):
+      return all((addr & mask != network & mask) for addr, mask in addresses)
+
+    def _NextUnusedAddress(network, netmask, used_addresses):
+      # Excludes '0' and broadcast.
+      for suffix in range(1, 0xFFFFFFFF & ~netmask):
+        candidate = network | suffix
+        if candidate not in used_addresses:
+          return candidate
+
+    def HasHostAddress():
+      _, host_address = self._GetHostAddresses(host_iface)
+      return bool(host_address)
+
+    if not HasHostAddress():
+      if platform.GetHostPlatform().GetOSName() == 'mac':
+        if 'Telemetry' not in subprocess.check_output(
+            ['networksetup', '-listallnetworkservices']):
+          subprocess.check_call(
+              ['/usr/bin/sudo', 'networksetup',
+               '-createnetworkservice', 'Telemetry', host_iface])
+          subprocess.check_call(
+              ['/usr/bin/sudo', 'networksetup',
+               '-setmanual', 'Telemetry', '192.168.123.1', '255.255.255.0'])
+      elif platform.GetHostPlatform().GetOSName() == 'linux':
+        with open(self._NETWORK_INTERFACES) as f:
+          orig_interfaces = f.read()
+        if self._INTERFACES_INCLUDE not in orig_interfaces:
+          interfaces = '\n'.join([
+              orig_interfaces,
+              '',
+              '# Added by Telemetry.',
+              self._INTERFACES_INCLUDE])
+          self._WriteProtectedFile(self._NETWORK_INTERFACES, interfaces)
+        interface_conf_file = self._TELEMETRY_INTERFACE_FILE.format(host_iface)
+        if not os.path.exists(interface_conf_file):
+          interface_conf_dir = os.path.dirname(interface_conf_file)
+          if not os.path.exists(interface_conf_dir):
+            subprocess.call(['/usr/bin/sudo', '/bin/mkdir', interface_conf_dir])
+            subprocess.call(
+                ['/usr/bin/sudo', '/bin/chmod', '755', interface_conf_dir])
+          interface_conf = '\n'.join([
+              '# Added by Telemetry for RNDIS forwarding.',
+              'allow-hotplug %s' % host_iface,
+              'iface %s inet static' % host_iface,
+              '  address 192.168.123.1',
+              '  netmask 255.255.255.0',
+              ])
+          self._WriteProtectedFile(interface_conf_file, interface_conf)
+          subprocess.check_call(['/usr/bin/sudo', 'ifup', host_iface])
+      logging.info('Waiting for RNDIS connectivity...')
+      util.WaitFor(HasHostAddress, 30)
+
+    addresses, host_address = self._GetHostAddresses(host_iface)
+    assert host_address, 'Interface %s could not be configured.' % host_iface
+
+    host_ip, netmask = host_address  # pylint: disable=unpacking-non-sequence
+    network = host_ip & netmask
+
+    if not _IsNetworkUnique(network, addresses):
+      logging.warning(
+        'The IP address configuration %s of %s is not unique!\n'
+        'Check your /etc/network/interfaces. If this overlap is intended,\n'
+        'you might need to use: ip rule add from <device_ip> lookup <table>\n'
+        'or add the interface to a bridge in order to route to this network.'
+        % (host_address, host_iface)
+      )
+
+    # Find unused IP address.
+    used_addresses = [addr for addr, _ in addresses]
+    used_addresses += [self._IpPrefix2AddressMask(addr)[0]
+                       for addr in self._GetDeviceAddresses(device_iface)]
+    used_addresses += [host_ip]
+
+    device_ip = _NextUnusedAddress(network, netmask, used_addresses)
+    assert device_ip, ('The network %s on %s is full.' %
+                       (host_address, host_iface))
+
+    host_ip = _Long2Ip(host_ip)
+    device_ip = _Long2Ip(device_ip)
+    netmask = _Long2Ip(netmask)
+
+    # TODO(szym) run via su -c if necessary.
+    self._device.RunShellCommand(
+        'ifconfig %s %s netmask %s up' % (device_iface, device_ip, netmask))
+    # Enabling the interface sometimes breaks adb.
+    self._device.WaitUntilFullyBooted()
+    self._host_iface = host_iface
+    self._host_ip = host_ip
+    self.device_iface = device_iface
+    self._device_ip = device_ip
+
+  def _TestConnectivity(self):
+    with open(os.devnull, 'wb') as devnull:
+      return subprocess.call(['ping', '-q', '-c1', '-W1', self._device_ip],
+                             stdout=devnull) == 0
+
+  def OverrideRoutingPolicy(self):
+    """Override any routing policy that could prevent
+    packets from reaching the rndis interface
+    """
+    policies = self._device.RunShellCommand('ip rule')
+    if len(policies) > 1 and not 'lookup main' in policies[1]:
+      self._device.RunShellCommand('ip rule add prio 1 from all table main')
+      self._device.RunShellCommand('ip route flush cache')
+
+  def RestoreRoutingPolicy(self):
+    policies = self._device.RunShellCommand('ip rule')
+    if len(policies) > 1 and re.match("^1:.*lookup main", policies[1]):
+      self._device.RunShellCommand('ip rule del prio 1')
+      self._device.RunShellCommand('ip route flush cache')
+
+  def _CheckConfigureNetwork(self):
+    """Enables RNDIS and configures it, retrying until we have connectivity."""
+    force = False
+    for _ in range(3):
+      device_iface, host_iface = self._CheckEnableRndis(force)
+      self._ConfigureNetwork(device_iface, host_iface)
+      self.OverrideRoutingPolicy()
+      # Sometimes the first packet will wake up the connection.
+      for _ in range(3):
+        if self._TestConnectivity():
+          return
+      force = True
+    self.RestoreRoutingPolicy()
+    raise Exception('No connectivity, giving up.')