#!/usr/bin/env zsh
################################################################################
## Custom network initialization script.
## 2012-10-29
################################################################################
## Deps: wpa_supplicant, ccrypt (optional)

## We need to use wpa_supplicant's unencrypted config file. We store it in a
## variable to keep it secure, but the 'wpa_supplicant' command requires a
## file. We cannot use a pipe for that, because in that case the config would be
## accessible unencrypted. So we need to use an internal path with a syntax like
## <(...) which is not specified by POSIX. Ksh, bash and zsh can handle it.

## Use 'wpa_passphrase essid $PW >> /etc/wpa_supplicant.conf', where PW is a
## variable containing the password.  You can set PW securely by using a shell
## built-in like 'read -s PW'.

## There is an Emacs plugin for editing crypted files directly. See 'man
## ccrypt'.

# if [ -z "$(command -v ccrypt)" ]; then
#     echo "You need to have 'ccrypt' installed."
#     exit
# fi

if [ $(id -u) -ne 0 ]; then
    echo "You must be root to run this script."
    exit
fi

NET_INTERFACE=wlan0
WPA_SUPPLICANT_CONF="$(cat /etc/wpa_supplicant.conf)"
TIMEOUT_LIMIT=500

pkill wpa_supplicant

if [ "$OSTYPE" = "linux-gnu" ] ; then
    ## Clean running processes if any.
    pkill dhcpcd

    ## In case network inteface is not up.
    ip link set ${NET_INTERFACE} up

    # Associate if needed.
    if [ -n "$(iwconfig ${NET_INTERFACE} | grep 'Not-Associated')" ]; then
        wpa_supplicant -B -i ${NET_INTERFACE} -D wext -c <(echo "${WPA_SUPPLICANT_CONF}")
    fi

    ## Wait until wpa_supplicant has finished association.
    i=0
    while [ -n "$(iwconfig ${NET_INTERFACE} | grep 'off/any')" ] && [ $i -lt $TIMEOUT_LIMIT ] ; do
        i=$(($i+1))
    done

    ## Get IP.
    dhcpcd ${NET_INTERFACE}

else
## BSD
## Same comments as for Linux.

    pkill dhclient
    pkill wpa_supplicant

    ifconfig wlan0 up

    if [ -n "$(ifconfig ${NET_INTERFACE} | grep 'ssid ""')" ]; then
        wpa_supplicant -B -i ${NET_INTERFACE} -c <(echo "${WPA_SUPPLICANT_CONF}")
    fi

    i=0
    while [ -n "$(ifconfig ${NET_INTERFACE} | grep 'ssid ""')" ] && [ $i -lt $TIMEOUT_LIMIT ] ; do
        i=$(($i+1))
    done

    dhclient ${NET_INTERFACE}
fi