#!/bin/sh

#set -e

PREREQ=""
prereqs()
{
    echo "$PREREQ"
}

case $1 in
    prereqs)
        prereqs
        exit 0
        ;;
esac

. /scripts/functions

EXE="$(readlink -f /sbin/tailscaled)" && [ -f "$EXE" ] || exit 1
PIDFILE="/run/tailscale.pid"
TAILSCALE_SHUTDOWN_TIMEOUT=60
TAILSCALE_LOGOUT=
IFDOWN="*"

if [ -e /etc/tailscale/initramfs/config ]; then
    . /etc/tailscale/initramfs/config
fi

wait_for_tailscaled()
{
    # shellcheck disable=SC2039
    # SC2039: In POSIX sh, 'local' is undefined.
    local pid exe timer="$TAILSCALE_SHUTDOWN_TIMEOUT"
    pid="$(cat "$PIDFILE" 2>/dev/null)" || return 1

    while [ $timer -gt 0 ] && exe="$(readlink -f "/proc/$pid/exe" 2>/dev/null)"; do
        if [ "$exe" = "$EXE" ]; then
            echo "$pid"
            return 0
        fi
        sleep 1
        timer=$(( timer - 1 ))
    done
    return 1
}


if PID="$(wait_for_tailscaled)"; then
    if [ -n "$TAILSCALE_LOGOUT" ]; then
        log_begin_msg "Logging out of tailscale"
        /bin/tailscale --socket=/run/tailscale/tailscaled.sock logout 2>>/run/initramfs/tailscale.log || true
        log_end_msg
    fi

    log_begin_msg "Stopping tailscale"
    kill -TERM "$PID"
    wait "$PID" || true
    /sbin/tailscaled -cleanup 2>>/run/initramfs/tailscale.log
    log_end_msg
fi

rm -f "$PIDFILE"

if [ "$BOOT" != nfs ] && [ "$IFDOWN" != none ]; then
    for IFACE in /sys/class/net/$IFDOWN; do
        [ -e "$IFACE" ] || continue
        IFACE="${IFACE#/sys/class/net/}"
        log_begin_msg "Bringing down $IFACE"
        ip link    set   dev "$IFACE" down
        ip address flush dev "$IFACE"
        ip route   flush dev "$IFACE"
        log_end_msg
    done
fi

exit 0