#
# Setup and BASH utility functions for use in hotplug agents
#
# Most essential parameters are passed from the kernel using
# environment variables.  For more information, see the docs
# on-line at http://linux-hotplug.sourceforge.net or the
# sources for each hotplug-aware kernel subsystem.
#
# $Id: hotplug.functions,v 1.24 2004/03/29 19:25:59 kroah Exp $
#
#

# DEBUG=yes; export DEBUG
PATH=/bin:/sbin:/usr/sbin:/usr/bin

KERNEL=`uname -r`
MODULE_DIR=/lib/modules/$KERNEL

HOTPLUG_DIR=/etc/hotplug

if [ -f /etc/default/hotplug ]; then
    . /etc/default/hotplug
fi

if [ -x /usr/bin/logger ]; then
    LOGGER=/usr/bin/logger
elif [ -x /bin/logger ]; then
    LOGGER=/bin/logger
else
    unset LOGGER
fi
#
# for diagnostics
#
if [ -t 1 -a -z "$LOGGER" ]; then
    mesg () {
	echo "$@"
    }
elif [ -t 1 ]; then
   mesg () {
	echo "$@"
	$LOGGER -t $(basename $0)"[$$]" "$@"
   }
else
    mesg () {
	$LOGGER -t $(basename $0)"[$$]" "$@"
    }
fi

debug_mesg () {
    test "$DEBUG" = "" -o "$DEBUG" = no && return
    mesg "$@"
}

# provide env-like output when the real thing is not available
if [ ! -x /usr/bin/env ]; then
    env () {
	# bash prepends "declare -x " at the beginning of each line
	export -p | sed -e 's/^declare -x //'
    }
fi

# provide number_of_files, because wc in /usr/bin and maybe nfs mounted
number_of_files () {
   # ls "$1" | wc -l
   echo $(( 0 $(ls "$1" | sed -e 's/.*/+1/') ))
}

# provide which-like output when the real thing is not available
if [ ! -x /usr/bin/which ]; then
   which () {
	command -v "$1" 2>/dev/null
   }
fi

#
# Not "modprobe --autoclean" ... one driver module can handle many
# devices.  Unloading should be done when no devices are present.
# Autocleaning happens if none of the devices are open, once any of
# them gets opened; wrong timing.
#
MODPROBE="/sbin/modprobe -s -q"
#MODPROBE="/sbin/modprobe -vs"


# return true if the argument is a blacklisted module
is_blacklisted() {
    MODULE_EXPR="$(echo $1 | sed -e 's/[-_]/[-_]/g')"
    if grep -qs "^${MODULE_EXPR}$" \
	    $HOTPLUG_DIR/blacklist $HOTPLUG_DIR/blacklist.d/*; then
	return 0
    fi
    return 1
}


####################################################################
#
# usage: load_driver type filename description
#
# modprobes driver module(s) if appropriate, and optionally
# invokes a driver-specific setup script (or user-mode driver).
#
# the "modules.*map" format file is guaranteed to exist
#
load_drivers ()
{
    local LOADED TYPE FILENAME DESCRIPTION LISTER
    DRIVERS=""

    # make this routine more readable
    TYPE=$1
    FILENAME=$2
    DESCRIPTION=$3

    # should we use usbmodules, pcimodules?  not on 2.5+, because sysfs
    # ought to expose the data we need to find all candidate drivers.
    # (on 2.5.48 it does for usb; but maybe not yet for pci.)
    case "$KERNEL" in
    2.2*|2.3*|2.4*)	LISTER=`which ${TYPE}modules` ;;
    *)			LISTER="" ;;
    esac

    if [ "$LISTER" != "" ]; then
	# lister programs MIGHT be preferable to parsing from shell scripts:
	# - usbmodules used for (a) multi-interface devices, (b) coldplug
	# - pcimodules used only for coldplug
	case $TYPE in
	usb)
	    # "usbutils-0.8" (or later) is needed in $PATH
	    # only works if we have usbfs
	    # ... reads more descriptors than are passed in env
	    # ... doesn't handle comment syntax either
	    if [ "$DEVICE" = "" -o ! -f "$DEVICE" ]; then
		LISTER=
	    else
		DRIVERS=`$LISTER --mapfile $FILENAME --device $DEVICE`
	    fi ;;

	pci)
	    debug_mesg "pcimodules is scanning more than $PCI_SLOT ..."
	    DRIVERS=`$LISTER`
	    ;;
	esac
    fi

    # try parsing by shell scripts if no luck yet
    if [ "$DRIVERS" = "" ]; then
	${TYPE}_map_modules < $FILENAME
    fi

    # FIXME remove dups and blacklisted modules from $DRIVERS here

    if [ "$DRIVERS" = "" ]; then
	return
    fi

    # Note that DRIVERS aren't all going to be modules.
    # For USB, some user-mode drivers or setup scripts may be listed.
    debug_mesg Setup $DRIVERS for $DESCRIPTION

    LOADED_DRIVERS=""
    # either kernel or user mode drivers may need to be set up
    for MODULE in $DRIVERS
    do
	# maybe driver modules need loading
        LOADED=false

	# check if the $MODULE has been already seen
	if echo "|$LOADED_DRIVERS|" | grep -qs "|$MODULE|"; then
	    # $MODULE is duplicated?
	    continue
	fi
	# XXX:
	# Even if $LOADED = false, we may not need to try loading it again.
	# or do we need to check $LOADED = true at end of the loop?
	LOADED_DRIVERS="$LOADED_DRIVERS|$MODULE"

	if ! lsmod | grep -qs "^$(echo $MODULE | sed -e 's/[-_]/[-_]/g') "; then
	    if is_blacklisted $MODULE; then
		debug_mesg "     $MODULE: blacklisted"
		continue
	    fi

	    # XXX: check PCI video modules
	    # On 2.4 kernel, $IGNORE_PCI_CLASS_DISPLAY hacks in pci.rc won't
	    # be used, so here checks drivers/video modules....
	    # It prevents from breaking some working systems. Bug#261958
	    if [ "$IGNORE_PCI_CLASS_DISPLAY" = "true" ] && \
		$MODPROBE -n -v "$MODULE" | grep -q '/drivers/video/' > /dev/null 2>&1; then
		mesg "     $MODULE: ignoring pci display module"
		continue
	    fi

	    # statically linked modules aren't shown by 'lsmod',
	    # and user mode drivers will ONLY have a setup script;
	    # it's not an error if a module doesn't exist or won't load.
	    if $MODPROBE -n $MODULE >/dev/null 2>&1 &&
		    ! $MODPROBE $MODULE >/dev/null 2>&1 ; then
		mesg "     $MODULE: can't be loaded"
	    else
		# /etc/modules.conf may have set non-default module
		# parameters ... handle per-device parameters in apps
		# (ioctls etc) not in setup scripts or modules.conf
		mesg "     $MODULE: loaded successfully"
		LOADED=true
	    fi
	else
	    # This module is already loaded
	    mesg "     $MODULE: already loaded"
	    LOADED=true
	fi

	# always run setup scripts after any matching kernel code has had
	# a chance to do its thing, no matter whether it was dynamically
	# or statically linked, or if there is only a user mode driver.
	# the script might re-enumerate usb devices after firmware download,
	# giving kernel code another chance.
	if [ -x $HOTPLUG_DIR/$TYPE/$MODULE ]; then
	    debug_mesg Module setup $MODULE for $DESCRIPTION
	    $HOTPLUG_DIR/$TYPE/$MODULE
	    LOADED=true
	fi

	if [ "$LOADED" = "false" ]; then
	    mesg "missing kernel or user mode driver $MODULE "
	fi
	if echo "$MODULE" | grep -q "usb-storage" > /dev/null 2>&1 ; then
	    [ -x /usr/sbin/updfstab ] &&  /usr/sbin/updfstab
	fi
    done
}

####################################################################
#
# usage: log_to_stdout filename
#
# writes a copy of the current hotplug event to stdout.
# add buffering, to avoid interleaving reports!
#
log_to_stdout ()
{
    if [ -x /bin/date ]; then
	echo "HOTPLUG_TIME='$(/bin/date)'"
    fi

    env | egrep -v '^PATH=|^PWD=|^_=|^OLDPWD=|^SHLVL=|^HOME='
    echo ''
    # empty line terminates events
}

# vim:syntax=sh