/usr/bin/pinger
#!/bin/sh

[ -z $1 ] && {
  echo "Usage: $0 <interface>"
  exit;
}

. /lib/config/uci.sh
. /lib/functions/network.sh

uci_add network defaultroute defaultroute

wan_led(){
  . /lib/irz/led_utils.sh
  local default_route_metric=$(ip route list | awk '/^default.*metric.*[0-9]+/{print $7}' | head -n 1)
  [ -z "$default_route_metric" ]||[ "$default_route_metric" -gt 99 ] && led_solid_red WAN || led_solid_green WAN
}

network_device_interface() {
  local ifname
  ifname=$(cat /tmp/state/network | awk -F. "/ifname='$1'/{print \$2}")
  [ -z "$ifname" ] && ifname=$(cat /tmp/state/network | awk -F. "/device='$1'/{print \$2}")
  echo $ifname
}

network_current_defaultroute() {
  local device
  device=$(cat /proc/net/route | awk '/^[a-z0-9.-]+?\t00000000/{print $1}' | head -n1)
  echo $(network_device_interface $device)
}

network_current_metric() {
  local ifname
  network_get_device ifname $1 || ifname=$1
  echo $(cat /proc/net/route | awk '/^'$ifname'\t00000000\t/{print $7}' | head -n 1)
}

set_default_route(){
  ## $1 - device name
  ## $2 - default gateway
  ## $3 - new metric

  local gateway addr default_route_interface_state default_route_interface_now device current_interface_metric

  default_route_interface_state=$(uci_get_state network defaultroute interface)
  current_interface_metric=$(network_current_metric $interface)

  ip route del default dev $1
  ip route add default dev $1 via $2 metric $3 2>&1 | grep -q 'File exists' && {
    logger -t "pinger[$$]" "$interface: cannot add default route! check routes priorities"
    ip route add default dev $1 via $2 metric 199
    return 0
  }

  default_route_interface_now=$(network_current_defaultroute)

  [ "$default_route_interface_state" != "$default_route_interface_now" ] && {
    uci_toggle_state network defaultroute interface $default_route_interface_now

    network_flush_cache
    network_get_gateway gateway $default_route_interface_now
    network_get_device  device  $default_route_interface_now
    network_get_ipaddr  addr    $default_route_interface_now

    ubus send defaultroute "{'ADDRESS': '$addr', 'DEVICE': '$device', 'INTERFACE': '$default_route_interface_now', 'GATEWAY': '$gateway', 'ACTION': 'change'}"
  }

  [ "$current_interface_metric" -lt "$3" ] && action=down
  [ "$current_interface_metric" -gt "$3" ] && action=up
  ubus send defaultroute "{'ACTION': '$action', 'INTERFACE': '$interface', 'DEVICE': '$1'}"

  wan_led
}

interface=$1

address=$(uci -q get network.$interface.ping_ip)
interval=$(uci -q get network.$interface.ping_intvl || echo 30)
maxfail=$(uci -q get network.$interface.ping_maxfail || echo 3)
count=$(uci -q get network.$interface.ping_count || echo 4)
size=$(uci -q get network.$interface.ping_size || echo 32)

use_as_defaultroute=$(uci -q get network.$interface.defaultroute)
[ "$use_as_defaultroute" = "0" ] && use_as_defaultroute=""

fail_count=0

network_get_device  devicename      $interface
network_get_gateway default_gateway $interface
network_get_ipaddr  iface_addr      $interface

default_metric=$(uci -q get network.$interface.metric || echo 0)

[ -n "$use_as_defaultroute" ] && [ -z "$default_gateway" ] && exit 126

if [ -n $use_as_defaultroute -a $default_metric -le 99 ]; then
  default_metric=$(( default_metric + 100 ))
  uci set network.$interface.metric=$default_metric
  uci commit network
fi

[ -n "$use_as_defaultroute" ] && worked_metric=$(( default_metric - 100 ))

[ -z $address ] && {
  test -n "$use_as_defaultroute" && set_default_route "$devicename" "$default_gateway" "$worked_metric"
  exit 127
}

[ -z $iface_addr ] && {
  exit 128
}

logger -t "pinger[$$]" "$interface: ping-test started for $address via $iface_addr"

while true; do
  ip link show dev $devicename 2>/dev/null | grep -q 'UP,' || exit 0
  metric=$(network_current_metric $interface)
  ping -c $count -s $size -q $address -I $iface_addr &>/dev/null
  res=$?
  if [ "$res" = "0" ]; then
    [ -n "$use_as_defaultroute" ] && [ "$metric" != "$worked_metric" ] && {
      logger -t "pinger[$$]" "$interface: ping-test successfull"
      test -n "$use_as_defaultroute" && set_default_route "$devicename" "$default_gateway" "$worked_metric"
      }

    [ -z "$use_as_defaultroute" ] && [ "$fail_count" -gt 0 ] && {
      logger -t "pinger[$$]" "$interface: ping-test successfull"
      }
    fail_count=0
  else
    [ -n "$use_as_defaultroute" ] && [ "$metric" != "$default_metric" ] && {
      fail_count=0
      logger -t "pinger[$$]" "$interface: ping-test fail"
      test -n "$use_as_defaultroute" && set_default_route "$devicename" "$default_gateway" "$default_metric"
      }

    [ -z "$use_as_defaultroute" ] && [ "$fail_count" = "0" ] && {
      logger -t "pinger[$$]" "$interface: ping-test fail"
      }

    fail_count=$(( fail_count + 1 ))
    [ "$fail_count" -ge "$maxfail" ] && {
      logger -t "pinger[$$]" "$interface: fail limit reached"
      sh -c "(sleep 1;ifup $interface)&"
      exit 0
      # sh -c "(sleep 5;ifup $interface)&"
      # ifdown $interface
      # fail_count=0
    }
  fi

  sleep $interval
done