#!/bin/bash
# Bryan's trivial wifi management script

[ -z "$IFACE" ] && IFACE=wlan0   # Wifi interface

[ $# -lt 1 ] && echo -e "wifi --list\nwifi --off\nwifi network [optional wpa pass]\nIFACE=interface wifi ... to specify wifi interface different from 'wlan0'." && exit 0

if test "$1" = "--list"; then
  sudo ifconfig $IFACE up
  sudo iwlist $IFACE scanning | grep -e ESSID -e "Quality" -e "Encryption" | paste -d " " - - - | tr -s "[:blank:]" | sed -e "s/ESSID://;s/ dBm/dBm/;s/^ //;s/Signal //;s/Quality=//" | sort -r
  exit 0
fi

if test "$1" = "--off"; then
  sudo dhclient -r || sudo killall dhclient 2>/dev/null
  sudo killall wpa_supplicant 2>/dev/null
  sudo killall -9 wpa_supplicant 2>/dev/null
  sudo ifconfig $IFACE down
  exit 0
fi

# Reset interface cruft
sudo dhclient -r || sudo killall dhclient 2>/dev/null
sudo killall wpa_supplicant 2>/dev/null

# Randomize hardware MAC address
hwaddr=`dd if=/dev/urandom bs=1 count=3 2>/dev/null | od -w1  -A n -tx1 | tr -d '\n' | tr -d ' ' | sed -e 's/*/00/'`
sudo ifconfig $IFACE down
sudo ifconfig $IFACE hw ether "5cc5d4${hwaddr}"
sleep 1

# Bring up interface
if test -n "$2"; then
  wpa_passphrase "$1" "$2" >/tmp/.wpa
  sudo iwconfig $IFACE essid "$1" && sleep 1
  sudo wpa_supplicant -B -i$IFACE -c/tmp/.wpa && sleep 2 && sudo dhclient -v $IFACE && sudo ifconfig $IFACE up
  rm -f /tmp/.wpa
else
  echo Open network
  sudo iwconfig $IFACE essid "$1" && sleep 1
  sudo dhclient -v $IFACE && sudo ifconfig $IFACE up
fi