#!/bin/sh
#
# Copyright 2009, 2010 Red Hat, Inc.
# License: GPLv2
# Author: Dan Horák <dhorak@redhat.com>
#
# unblock devices listed in various config files and wait until they are ready
#
# it uses dasd and zfcp config file
# config file syntax:
# deviceno   options
# or
# deviceno   WWPN   FCPLUN
#
# also processes the system ccw config file and network interface configurations
#
# requires: echo, sleep, modprobe, grep, printf, sed.
#
# it is used in
#   anaconda
#   dracut generated initramfs
#   normal system startup driven by upstart
#

DASDCONFIG=/etc/dasd.conf
ZFCPCONFIG=/etc/zfcp.conf
ZNETCONFIG=/etc/ccw.conf
BLACKLIST=/proc/cio_ignore
VERBOSE=
PATH=/bin:/sbin
ALL_DEVICES=		# list of all unblocked devices
WAITING_TIMEOUT=60	# maximum time to wait for all devices to appear
WAITING_TOTAL=0		# actual time spent waiting for devices

usage()
{
    echo "Usage: $CMD [-h|--help] [-V|--verbose] [-d|--device <deviceid>]"
    echo "    -h|--help                 print this message"
    echo "    -V|--verbose              be verbose"
    echo "    -d|--device <deviceid>    unblock and wait for specified device"
    exit 1
}

# accepts single device, comma-separated lists and dash separated ranges and their combinations
# the comma separated list is split so we minimize the effect of unsuccessful freeing
free_device()
{
    local DEV DEV_LIST

    [ -z "$1" ] && return

    DEV_LIST=$(echo "$1" | sed 'y/ABCDEF/abcdef/' | sed 's/,/ /g')

    for DEV in $DEV_LIST; do
        [ $VERBOSE ] && echo "Freeing device(s) $DEV"
        if ! echo "free $DEV" > $BLACKLIST 2> /dev/null ; then
    	    echo "Error: can't free device(s) $DEV"
	else
	    if [ -z $ALL_DEVICES ]; then
		ALL_DEVICES="$DEV"
	    else
		ALL_DEVICES="$ALL_DEVICES,$DEV"
	    fi
	fi
    done
}

# wait until a device appears on the ccw bus
wait_on_single_device()
{
    local DEVICE_ONLINE DEV
    
    [ -z "$1" ] && return
    
    DEV="$1"
    DEVICE_ONLINE="/sys/bus/ccw/devices/$DEV/online"

    [ $VERBOSE ] && echo "Waiting on device $DEV"
    [ -f "$DEVICE_ONLINE" ] && return

    for t in 1 2 3 4 5
    do
	if [ $WAITING_TOTAL -ge $WAITING_TIMEOUT ]; then
	    [ $VERBOSE ] && echo "Waiting timeout of $WAITING_TIMEOUT seconds reached"
	    break
	fi
	WAITING_TOTAL=$(($WAITING_TOTAL + $t))
        [ $VERBOSE ] && echo "Waiting additional $t second(s) and $WAITING_TOTAL second(s) in total"
	sleep $t
	[ -f "$DEVICE_ONLINE" ] && return
    done
    echo "Error: device $DEV still not ready"
}

# wait until recently unblocked devices are ready
# at this point we know the content of ALL_DEVICES is syntacticly correct
wait_on_devices()
{
    OLD_IFS=$IFS
    IFS=","
    set $ALL_DEVICES
    for DEV in $*
    do
        IFS="."

        # get the lower bound for range or get the single device
        LOWER=${DEV%%-*}
	set $LOWER
        if [ $# -eq 1 ]; then
	    L0=0
	    L1=0
	    L2=$(printf "%d" "0x$1")
        else
	    L0=$(printf "%d" "0x$1")
	    L1=$(printf "%d" "0x$2")
	    L2=$(printf "%d" "0x$3")
        fi

        # get the upper bound for range or get the single device
        UPPER=${DEV##*-}
        set $UPPER
        if [ $# -eq 1 ]; then
	    U0=0
	    U1=0
	    U2=$(printf "%d" "0x$1")
        else
	    U0=$(printf "%d" "0x$1")
	    U1=$(printf "%d" "0x$2")
	    U2=$(printf "%d" "0x$3")
        fi

        IFS=$OLD_IFS

        # iterate thru all devices
	i=$L0
	while [ $i -le $U0 ]; do
            [ $i -eq $L0 ] && LJ=$L1 || LJ=0
            [ $i -eq $U0 ] && UJ=$U1 || UJ=3

	    j=$LJ
	    while [ $j -le $UJ ]; do
                [ $i -eq $L0 -a $j -eq $L1 ] && LK=$L2 || LK=0
                [ $i -eq $U0 -a $j -eq $U1 ] && UK=$U2 || UK=65535

		k=$LK
		while [ $k -le $UK ]; do
                    wait_on_single_device "$(printf %x.%x.%04x $i $j $k)"
		    k=$(($k + 1))
                done
		j=$(($j + 1))
            done
	    i=$(($i + 1))
        done
    done
}

process_config_file()
{
    local CONFIG

    [ -z "$1" ] && return
    
    CONFIG="$1"
    if [ -f "$CONFIG" ]; then
        while read line; do
	    case $line in
		\#*) ;;
		*)
		    [ -z "$line" ] && continue
		    set $line
		    free_device $1
		    ;;
	    esac
	done < "$CONFIG"
    fi
}

# check how we were called
CMD=${0##*/}
DIR=${0%/*}
ARGS=$@
case $CMD in
    "dasd_cio_free")
	MODE_DASD="yes"
	;;
    "zfcp_cio_free")
	MODE_ZFCP="yes"
	;;
    "znet_cio_free")
	MODE_ZNET="yes"
	;;
    "device_cio_free")
	MODE_DASD="yes"
	MODE_ZFCP="yes"
	MODE_ZNET="yes"
	;;
    *)
	echo "Error: unknown alias '$CMD'."
	echo "Supported aliases are dasd_cio_free, zfcp_cio_free and znet_cio_free."
	exit 1
	;;
esac

# process command line options
while [ $# -gt 0 ]; do
    case $1 in
	-V|--verbose)
	    VERBOSE=yes
	    ;;
	-h|--help)
	    usage
	    ;;
	-d|--device)
	    shift
	    [ -n "$1" ] && DEVICE="$DEVICE,$1" || usage
	    ;;
	*)
	    echo "Error: unknown option $1"
	    usage
	    ;;
    esac
    shift
done

if [ ! -f $BLACKLIST ]; then
    echo "Error: $BLACKLIST kernel interface doesn't exist"
    exit 2
fi

if [ "$DEVICE" ]; then
    [ $VERBOSE ] && echo "Freeing specific devices"
    free_device $DEVICE
    wait_on_devices
    exit 0
fi

if [ $VERBOSE ]; then
    echo -n "Freeing devices:"
    [ $MODE_DASD ] && echo -n " dasd"
    [ $MODE_ZFCP ] && echo -n " zfcp"
    [ $MODE_ZNET ] && echo -n " znet"
    echo
fi

[ $MODE_DASD ] && process_config_file $DASDCONFIG
[ $MODE_ZFCP ] && process_config_file $ZFCPCONFIG

if [ $MODE_DASD ]; then
    # process the device list defined as option for the dasd module
    DEVICES=$(modprobe --showconfig | grep "options[[:space:]]\+dasd_mod" | \
	sed -e 's/.*[[:space:]]dasd=\([^[:space:]]*\).*/\1/' -e 's/([^)]*)//g' \
	-e 's/nopav\|nofcx\|autodetect\|probeonly//g' -e 's/,,/,/g' -e 's/^,//' -e 's/,$//')

    for DEVRANGE in $(echo $DEVICES | sed 's/,/ /g'); do
	free_device $DEVRANGE
    done
fi

if [ $MODE_ZNET ]; then
    # process the config file
    if [ -f "$ZNETCONFIG" ]; then
        while read line; do
	    case $line in
		\#*) ;;
		*)
		    [ -z "$line" ] && continue
		    # grep 2 or 3 channels from each "<nettype>,<subchannels>,<options>" line
		    DEVICES=$(echo $line | grep -E -i -o "([0-9]\.[0-9]\.[a-f0-9]+,){1,2}([0-9]\.[0-9]\.[a-f0-9]+)")
		    free_device $DEVICES
		    ;;
	    esac
	done < "$ZNETCONFIG"
    fi
    # process channels from network interface configurations
    for line in $(grep -E -i -h "^[[:space:]]*SUBCHANNELS=['\"]?([0-9]\.[0-9]\.[a-f0-9]+,){1,2}([0-9]\.[0-9]\.[a-f0-9]+)['\"]?([[:space:]]+#|[[:space:]]*$)" /etc/sysconfig/network-scripts/ifcfg-* 2> /dev/null)
    do
	eval "$line"
        free_device $SUBCHANNELS
    done
fi

[ -z "$ALL_DEVICES" ] && exit 0

wait_on_devices