#!/bin/bash /usr/lib/turtle/turtle_module
VERSION="0.6"
DESCRIPTION="uPnP Port Forwarding"
AUTHOR="Shad"
CONF=/tmp/upnp_portfwd.form


: ${DIALOG_OK=0}
: ${DIALOG_CANCEL=1}
: ${DIALOG_HELP=2}
: ${DIALOG_EXTRA=3}
: ${DIALOG_ITEM_HELP=4}
: ${DIALOG_ESC=255}

function configure {
  if [ -s /etc/config/upnp_portfwd ]
  then
    upnp_portfwd_lport=$(uci get upnp_portfwd.lport)
    upnp_portfwd_rport=$(uci get upnp_portfwd.rport)
    upnp_portfwd_proto=$(uci get upnp_portfwd.protocol)
  else
    touch /etc/config/upnp_portfwd
  fi

  dialog --ok-label "Submit" \
    --help-button \
    --title "uPnp Port Forwarding Configuration" \
    --form "Port Forward\n\n\
Router Port: External port of router to be forwarded\n\
Local Port:  Port of service running in Turtle's WAN\n\
Protocol:    tcp or udp\n \n" 16 60 3\
    "Router Port:"	1 1	"$upnp_portfwd_rport"   1 14 48 0 \
    "Local Port:"	2 1	"$upnp_portfwd_lport"	2 14 48 0 \
    "Protocol:"		3 1	"$upnp_portfwd_proto"	3 14 48 0 \
  2>$CONF

  return=$?

  case $return in
    $DIALOG_OK)
      cat $CONF | { 
        read -r upnp_portfwd_rport
        read -r upnp_portfwd_lport
        read -r upnp_portfwd_proto
        touch /etc/config/upnp_portfwd
	uci set upnp_portfwd.lport="$upnp_portfwd_lport"
	uci set upnp_portfwd.rport="$upnp_portfwd_rport"
	uci set upnp_portfwd.protocol="$upnp_portfwd_proto"
        uci commit upnp_portfwd
        rm $CONF
      };;
    $DIALOG_CANCEL)
      rm $CONF
      clear
      exit;;
    $DIALOG_HELP)
      dialog --title "Help" \
        --msgbox "\
uPnP Portfwd is a service which provides automatic port forwarding when connected to some uPnP enabled routers.\nThis service is typically used to provide a 
convenient and persistent DIRECT shell from the outside into the LAN Turtle so that a remote "proxy" server or host is not needed.\n*IF* the router is uPnP enabled
and forwards the port it would be possible to connect directly to the Turtle from any arbitrary/anonymous location, even from TOR.\n \n
Remote Port - External port on the router to be forwarded to the Turtle.\n \n\
Local Port - The port where a local service is running in the Turtle (Tipically 22 -ssh-)\n \n\
Protocol - TCP or UDP (tcp for ssh)\n \n\
Example: Per the defaults, the router will forward its external port 45000 to the LAN Turtle port 22. In this scenario one may establish a direct connection to the 
LAN Turtle by ssh'ing into the router's external interface port 45000: ssh -p 45000 root@external.router.ip \n \n
While this won't work in many cases, it may come handy when it does, which is frequent for some telco provided SOHO routers.\n \n\
" 20 60
      configure
      ;;
    $DIALOG_ESC)
      clear;;
  esac
}



function start {
	if [ ! -e "/etc/config/upnp_portfwd" ]; then
		touch /etc/config/upnp_portfwd
		uci set upnp_portfwd.lport="22"                                                                                                                        
    
	        uci set upnp_portfwd.rport="45000"                                                                                                                     
    
	        uci set upnp_portfwd.protocol="tcp"                                                                                                                    
    
	        uci commit upnp_portfwd
	fi
	if [ ! -e "/usr/bin/upnpc" ]; then
		opkg update
		opkg install miniupnpc
	fi

	ETH1_IP="`ifconfig eth1 | grep "inet addr" | awk -F: '{ print $2; }' | awk '{ print $1; }'`"
	
	iptables -t filter -I INPUT 1 -i eth1 -j ACCEPT # Kludge to allow uPnP work - Maybe a more specific way to do it?
	upnpc -a $ETH1_IP $(uci get upnp_portfwd.lport) $(uci get upnp_portfwd.rport) $(uci get upnp_portfwd.protocol)
	iptables -I INPUT 1 -i eth1 -p $(uci get upnp_portfwd.protocol) --dport $(uci get upnp_portfwd.lport) -j ACCEPT
	
	FWDRULE="`upnpc -l | grep "$(uci get upnp_portfwd.rport)->" | tail -1`"
        if [ "$FWDRULE" == "" ]; then                                  
		uci set upnp_portfwd.enabled="0"
        else                                                           
                uci set upnp_portfwd.enabled="1"                                                 
        fi                               
	uci commit upnp_portfwd
	iptables -t filter -D INPUT -i eth1 -j ACCEPT 


}


function stop {
	iptables -t filter -I INPUT 1 -i eth1 -j ACCEPT 
	upnpc -d $(uci get upnp_portfwd.rport) $(uci get upnp_portfwd.protocol)
	iptables -t filter -D INPUT -i eth1 -j ACCEPT
	iptables -D INPUT -i eth1 -p $(uci get upnp_portfwd.protocol) --dport $(uci get upnp_portfwd.lport) -j ACCEPT
	uci set upnp_portfwd.enabled="0"
	uci commit upnp_portfwd
}

function status {
	if [ "$(uci get upnp_portfwd.enabled 2>/dev/null)" == "1" ]; then
		echo "1"
	else
		echo "0"
	fi
}