tools/simwifi/udhcpc.script

#!/bin/sh
# Busybox udhcpc dispatcher script.
# Copyright (C) 2009 by Axel Beckert.
# Copyright (C) 2014 by Michael Tokarev.
#
# Based on the busybox example scripts and the old udhcp source
# Modified base on default.scripts.

log() {
  logger -t "udhcpc[$PPID]" -p daemon.$1 "$interface: $2"
}

SIMWIFILOG_FILE=/var/run/simwifi/simwifi.log
DEFCONF_FILE=/var/run/simwifi/simwifi.conf
case $1 in
  bound|renew)

  # Configure new IP address.
  # Do it unconditionally even if the address hasn't changed,
  # to also set subnet, broadcast, mtu, ...
  busybox ifconfig $interface ${mtu:+mtu $mtu} \
      $ip netmask $subnet ${broadcast:+broadcast $broadcast}

  # defwan equals to wlanx, should add router and DEF_NS

  defwan=$(cat $DEFCONF_FILE | grep defwan | awk -F':' '{print $2}')
  [ ".$defwan" = ".wlan0" ] && {
    # get current ("old") routes (after setting new IP)
    crouter=$(busybox ip -4 route show dev $interface |
              busybox awk '$1 == "default" { print $3; }')
    router="${router%% *}" # linux kernel supports only one (default) route
    if [ ".$router" != ".$crouter" ]; then
        # reset just default routes
        busybox ip -4 route flush exact 0.0.0.0/0 dev $interface
    fi

    if [ -n "$router" ]; then
        # special case for /32 subnets: use onlink keyword
        [ ".$subnet" = .255.255.255.255 ] \
            && onlink=onlink || onlink=
        busybox ip -4 route add default via $router dev $interface $onlink
        log info "udhcpc add router $router on $interface"
    fi

    DEF_NS="nameserver 8.8.8.8"
    RESOLV_CONF_FILE=${RESOLV_CONF:-/etc/resolv.conf}
    [ -f $RESOLV_CONF_FILE -a -z "$(cat $RESOLV_CONF_FILE | grep 8.8.8.8)" ] && {
        echo "$DEF_NS" >> "$RESOLV_CONF_FILE"
    }
  }

  log info "$1: IP=$ip/$subnet router=$router domain=\"$domain\" dns=\"$dns\" lease=$lease"
  ;;

    deconfig)
  busybox ip link set $interface up
  busybox ip -4 addr flush dev $interface
  busybox ip -4 route flush dev $interface
  log notice "deconfigured"
  ;;

    leasefail | nak)
  log err "configuration failed: $1: $message"
  ;;

    *)
  echo "$0: Unknown udhcpc command: $1" >&2
  exit 1
  ;;
esac