#!/bin/bash

CONFIGFILE="/etc/default/dnscrypt-proxy"
DAEMON="/usr/sbin/dnscrypt-proxy"

. $CONFIGFILE

start_instance() {
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) already running!"
        return
    fi

    # dnscrypt-proxy will work without this, but it drops privileges before
    # seeding the PRNG. libevent tries to work around a missing /dev/urandom
    # but it's safer just to make sure it is available in the chroot.
    if [ -n "${CHROOTDIR[$1]}" ]; then
        if [ "$(readlink -f ${CHROOTDIR[$1]})" != "/" ]; then
            if [ ! -d ${CHROOTDIR[$1]} ]; then
                mkdir -p ${CHROOTDIR[$1]}
                chmod 755 ${CHROOTDIR[$1]}
            fi
            if [ ! -d ${CHROOTDIR[$1]}/dev ]; then
                mkdir -p ${CHROOTDIR[$1]}/dev
                chmod 755 ${CHROOTDIR[$1]}/dev
            fi
            if [ ! -c ${CHROOTDIR[$1]}/dev/urandom ]; then
                mknod -m 666 ${CHROOTDIR[$1]}/dev/urandom c 1 9
            fi
        fi
    fi

    OPTIONS="-d"
    if [ -n "${LOCALADDRESS[$1]}" ]; then
        OPTIONS="${OPTIONS} --local-address=${LOCALADDRESS[$1]}"
    fi
    if [ -n "${PIDFILE[$1]}" ]; then
        OPTIONS="${OPTIONS} --pidfile=${PIDFILE[$1]}"
    fi
    if [ -n "${USER[$1]}" ]; then
        OPTIONS="${OPTIONS} --user=${USER[$1]}"
    fi
    if [ -n "${RESOLVERNAME[$1]}" ]; then
        OPTIONS="${OPTIONS} --resolver-name=${RESOLVERNAME[$1]}"
    fi
    if [ -n "${RESOLVERSLIST[$1]}" ]; then
        OPTIONS="${OPTIONS} --resolvers-list=${RESOLVERSLIST[$1]}"
    fi
    if [ -z "${RESOLVERNAME[$1]}" ] && [ -n "${RESOLVERADDRESS[$1]}" ]; then
        OPTIONS="${OPTIONS} --resolver-address=${RESOLVERADDRESS[$1]}"
    fi
    if [ -z "${RESOLVERNAME[$1]}" ] && [ -n "${PROVIDERNAME[$1]}" ]; then
        OPTIONS="${OPTIONS} --provider-name=${PROVIDERNAME[$1]}"
    fi
    if [ -z "${RESOLVERNAME[$1]}" ] && [ -n "${PROVIDERKEY[$1]}" ]; then
        OPTIONS="${OPTIONS} --provider-key=${PROVIDERKEY[$1]}"
    fi
    if [ "${EPHEMERALKEYS[$1]}" == "yes" ]; then
        OPTIONS="${OPTIONS} --ephemeral-keys"
    fi
    if [ -n "${CLIENTKEY[$1]}" ]; then
        OPTIONS="${OPTIONS} --client-key=${CLIENTKEY[$1]}"
    fi
    if [ -n "${EDNSPAYLOADSIZE[$1]}" ]; then
        OPTIONS="${OPTIONS} --edns-payload-size=${EDNSPAYLOADSIZE[$1]}"
    fi
    if [ -n "${MAXACTIVEREQUESTS[$1]}" ]; then
        OPTIONS="${OPTIONS} --max-active-requests=${MAXACTIVEREQUESTS[$1]}"
    fi
    if [ "${TCPONLY[$1]}" == "yes" ]; then
        OPTIONS="${OPTIONS} --tcp-only"
    fi
    if [ -n "${PLUGINS[$1]}" ]; then
        for plugin in ${PLUGINS[$1]}
        do
            OPTIONS="${OPTIONS} --plugin=${plugin}"
        done
    fi
    if [ -n "${LOGLEVEL[$1]}" ]; then
        OPTIONS="${OPTIONS} --loglevel=${LOGLEVEL[$1]}"
    fi
    if [ -n "${LOGFILE[$1]}" ]; then
        OPTIONS="${OPTIONS} --logfile=${LOGFILE[$1]}"
    fi
    $DAEMON $OPTIONS
}

stop_instance() {
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ ! -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) is not running!"
        return
    fi
    echo "Stopping dnscrypt-proxy (instance $1)..."
    kill $(cat ${PIDFILE[$1]})
}

status_instance() {
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ ! -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) is not running."
        return
    fi
    PID=$(cat ${PIDFILE[$1]})
    if [ -z "$PID" ]; then
        echo "PID file is empty! dnscrypt-proxy (instance $1) does not appear to be running, but there is a stale PID file."
    elif kill -0 $PID ; then
        echo "dnscrypt-proxy (instance $1) is running."
    else
        echo "dnscrypt-proxy (instance $1) is not running, but there is a stale PID file."
    fi
}

start() {
    for i in `/usr/bin/seq 0 $((${#PIDFILE[@]}-1))`
    do
        start_instance $i
    done
}

stop() {
    for i in `/usr/bin/seq 0 $((${#PIDFILE[@]}-1))`
    do
        stop_instance $i
    done
}

status() {
    for i in `/usr/bin/seq 0 $((${#PIDFILE[@]}-1))`
    do
        status_instance $i
    done
}

case "$1" in
    'start')
        start
        ;;
    'stop')
        stop
        ;;
    'restart')
        stop
        start
        ;;
    'status')
        status
        ;;
    *_start)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        start_instance $INSTANCE
        ;;
    *_stop)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        stop_instance $INSTANCE
        ;;
    *_restart)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        stop_instance $INSTANCE
        sleep 1
        start_instance $INSTANCE
        ;;
    *_status)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        status_instance $INSTANCE
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|status|#_start|#_stop|#_restart}"
        exit 1
        ;;
esac