#!/bin/sh
#
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

set -e

# Only run this script on test machines that run in the lab.
# See autotest/server/hosts/site_host.py for more information.
if [ ! -f /mnt/stateful_partition/.labmachine ]; then
  exit 0
fi

NON_ETHERNET_DRIVERS="cdc_ether"

# Returns 0 if $1 is a non-Ethernet driver, or 1 otherwise.
is_non_ethernet_driver() {
  local driver="$1"
  local non_ethernet_driver

  for non_ethernet_driver in ${NON_ETHERNET_DRIVERS}; do
    if [ "${driver}" = "${non_ethernet_driver}" ]; then
      return 0
    fi
  done
  return 1
}

# Shows the list of Ethernet interfaces found on the system.
find_ethernet_interfaces() {
  local device_path
  local driver_path
  local driver

  for device_path in /sys/class/net/eth*; do
    driver_path="${device_path}/device/driver"
    if [ -e "${driver_path}" ]; then
      driver=$(basename $(readlink -f "${driver_path}"))
      if ! is_non_ethernet_driver "${driver}"; then
        basename "${device_path}"
      fi
    fi
  done
}

for eth in $(find_ethernet_interfaces); do
  # Ping itself doesn't work on test images in a VM.
  PING="curl --interface ${eth} -o /dev/null www.google.com"

  if ${PING}; then
    exit 0
  fi

  ifconfig ${eth} down
  ifconfig ${eth} up
  sleep 5

  if ${PING}; then
    echo "Reconfigured using ifconfig down/up."
    exit 1
  fi

  initctl stop flimflam || echo "Flimflam was not running."
  initctl start flimflam

  sleep 5

  if ${PING}; then
    exit 1
  fi
done

# Last chance - reboot if we can't get any connectivity.
echo "All efforts to recover ethernet have been exhausted. Rebooting."
(sleep 5 && reboot) &
exit 1