#!/bin/bash

function res {
    #logger -t netcheck "$1"
    echo "$1"
}

# Try multiple times, since we might be doing this right after boot, when
# stuff's not upish yet
for (( t=0 ; t < 3 ; t = t + 1 )) ; do
    dip=$(host -t A debathena.mit.edu)
    res=$?
    if [[ $res == 0 ]] ; then
	break
    fi
done
if [[ $res != 0 ]] ; then
    res "You seem not to have Internet.  Connect your computer to an Ethernet cable or configure your wireless, then try again."
    exit 2
fi

dip=$(echo "$dip" | tail -n 1 | awk '{print $4}')

if [[ "$dip" = "10.72.0.47" ]] ; then
    res "You seem to be on MITNET but not have registered this computer.  Try opening Firefox and visiting any website to register, then try again."
    exit 3
elif [[ "$(echo $dip | cut -d . -f 1)" = "18" ]] ; then
    #logger -t netcheck "Netcheck success!"
    exit 0
else
    res "You seem to be on some non-MIT network that requires registration.  Try opening Firefox and visiting any website to register, then try again."
    exit 4
fi