#!/bin/sh

helpmsg()
{
  echo "get_ip - determine external IP address"
  echo
  echo "Usage: $0 [option]"
  echo "    -w, --webcm    - use webcm CGI handler method [default]"
  echo "    -d, --dsld     - use showdsldstat method (use only with kernel 2.6 firmwares)"
  echo "    -e, --extquery - use external site query method"
  echo "    -?, --help     - print this help message"
  echo
}

local ip=""
local retval=0

case "$1" in
  ""|-w|--webcm)
    local pw=$(/bin/allcfgconv -C ar7 -c -o - | sed -ne '/^webui[[:space:]]*{/,/^}/{
/=/{s/[[:space:]]*=[[:space:]]*/=/;s/^[[:space:]]*//;p}
}' | grep '^password=' | cut -d '"' -f2)
    retval=$?
    if [ $retval != 0 ]; then
      echo "get_ip error (exit code $retval)" >&2
      exit $retval
    fi
    export POST_DATA="getpage=/usr/www/all/html/query.txt&login:command/password=$pw&var:cnt=1&var:n0=connection0:pppoe:status/ip"
    ip=$(echo -n "$POST_DATA" | REQUEST_METHOD="POST" REMOTE_ADDR="127.0.0.1" CONTENT_TYPE="application/x-www-form-urlencoded" CONTENT_LENGTH=${#POST_DATA} /usr/www/html/cgi-bin/webcm | sed -e '1,/^$/d;$d')
    retval=$?
    ;;
  -d|--dsld)
    ip=$(/sbin/showdsldstat | grep "0: ip" | cut -d\/ -f1 | cut -d ' ' -f3)
    retval=$?
    ;;
  -e|--extquery)
    ip=$(wget -q -O - http://checkip.dyndns.org | grep -Eo '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+')
    retval=$?
    ;;
  -?|--help)
    helpmsg
    exit 0
    ;;
  *)
    helpmsg >&2
    exit 1
esac

if [ $retval == 0 ]; then
  echo "$ip"
  exit 0
fi
echo "get_ip error (exit code $retval)" >&2
exit $retval