#!/bin/sh
# This script mounts USB mass storage devices when they are plugged in
# and unmounts them when they are removed.
# Copyright (C) 2004, 2005 Martin Dickopp
#
# This file is free software; the copyright holder gives unlimited
# permission to copy and/or distribute it, with or without
# modifications, as long as this notice is preserved.
#
# This file is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE.
#
set -e
exec > /dev/null 2>&1


# Log a string via the syslog facility.
log()
{
    if test $1 != debug || expr "$VERBOSE" : "[yY]" > /dev/null; then
	echo "usbmount[$$] -- $2" >> $LOGFILE
    fi
}


# Test if the first parameter is in the list given by the second
# parameter.
in_list()
{
    for v in $2; do
	test "$1" != "$v" || return 0
    done
    return 1
}


# Test if /lib/udev/vol_id is executable.
test -x /lib/udev/vol_id || { log err "cannnot execute /lib/udev/vol_id"; exit 1; }

# Default values for configuration variables.
MOUNTPOINTS=""
FILESYSTEMS=""
MOUNTOPTIONS=""
FS_MOUNTOPTIONS=""
VERBOSE="no"

# Read configuration file.
if test -r /etc/usbmount/usbmount.conf; then
    . /etc/usbmount/usbmount.conf
fi


umask 022

if test "$1" = add; then

    # Acquire lock.
    log debug "trying to acquire lock /var/run/.usbmount.lock"
    lockfile-create --retry 5 /var/run/.usbmount || \
	{ log err "cannot acquire lock /var/run/.usbmount.lock"; exit 1; }
    trap '( lockfile-remove /var/run/.usbmount )' 0
    log debug "acquired lock /var/run/.usbmount.lock"

    # Try to read from the device.  Some devices need a few seconds
    # initialization time before they can be accessed.  Give up after
    # 20 seconds.  Thanks to Peter Stelmachovic for his help with
    # debugging this.
    log debug "testing whether $DEVNAME is readable"
    read_success=no
    for t in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19; do
	if dd if="$DEVNAME" of=/dev/null bs=512 count=1; then
	    read_success=yes
	    break
	fi
	log debug "attempt $t to read from $DEVNAME failed"
	sleep 1
    done
    if test "$read_success" != yes; then
	log err "cannot read from $DEVNAME"
	exit 1
    fi

    # Test if the device contains a filesystem.  If it doesn't, no
    # further action is required, but calling vol_id has the side effect
    # that the partition table is read and partition devices are created.
    if /lib/udev/vol_id "$DEVNAME" | egrep -q '^ID_FS_USAGE=(filesystem|disklabel)$'; then
	log debug "$DEVNAME contains a filesystem or disklabel"

	fstype="`/lib/udev/vol_id -t \"$DEVNAME\"`"
	log debug "$DEVNAME contains filesystem type $fstype"

	# Test if the filesystem type is in the list of filesystem
	# types to mount.
	if in_list "$fstype" "$FILESYSTEMS"; then

	    # Search an available mountpoint.
	    for v in $MOUNTPOINTS; do
		if test -d "$v" \
		    && ! grep -q "^[^ ][^ ]*  *$v " /proc/mounts; then
		    mountpoint="$v"
		    log debug "mountpoint $mountpoint is available for $DEVNAME"
		    break
		fi
	    done
	    if test -n "$mountpoint"; then
		# Determine mount options.
		options=
		for v in $FS_MOUNTOPTIONS; do
		    if expr "$v" : "-fstype=$fstype,."; then
			options="`echo \"$v\" | sed 's/^[^,]*,//'`"
			break
		    fi
		done
		if test -n "$MOUNTOPTIONS"; then
		    options="$MOUNTOPTIONS${options:+,$options}"
		fi

		# Mount the filesystem.
		log info "executing command: mount -t$fstype ${options:+-o$options} $DEVNAME $mountpoint"
		mount "-t$fstype" "${options:+-o$options}" "$DEVNAME" "$mountpoint"

		# Determine vendor and model.
		vendor=
		if test -r "/sys$DEVPATH/device/vendor"; then
		    vendor="`cat \"/sys$DEVPATH/device/vendor\"`"
		elif test -r "/sys$DEVPATH/../device/vendor"; then
		    vendor="`cat \"/sys$DEVPATH/../device/vendor\"`"
		elif test -r "/sys$DEVPATH/device/../manufacturer"; then
		    vendor="`cat \"/sys$DEVPATH/device/../manufacturer\"`"
		elif test -r "/sys$DEVPATH/../device/../manufacturer"; then
		    vendor="`cat \"/sys$DEVPATH/../device/../manufacturer\"`"
		fi
		vendor="`echo \"$vendor\" | sed 's/^ *//; s/ *$//'`"
		model=
		if test -r "/sys$DEVPATH/device/model"; then
		    model="`cat \"/sys$DEVPATH/device/model\"`"
		elif test -r "/sys$DEVPATH/../device/model"; then
		    model="`cat \"/sys$DEVPATH/../device/model\"`"
		elif test -r "/sys$DEVPATH/device/../product"; then
		    model="`cat \"/sys$DEVPATH/device/../product\"`"
		elif test -r "/sys$DEVPATH/../device/../product"; then
		    model="`cat \"/sys$DEVPATH/../device/../product\"`"
		fi
		model="`echo \"$model\" | sed 's/^ *//; s/ *$//'`"

		# Run hook scripts; ignore errors.
		export UM_DEVICE="$DEVNAME"
		export UM_MOUNTPOINT="$mountpoint"
		export UM_FILESYSTEM="$fstype"
		export UM_MOUNTOPTIONS="$options"
		export UM_VENDOR="$vendor"
		export UM_MODEL="$model"
		log info "executing command: run-parts /etc/usbmount/mount.d"
		run-parts /etc/usbmount/mount.d || :
	    else
		# No suitable mount point found.
		log warning "no mountpoint found for $DEVNAME"
		exit 1
	    fi
	fi
    else
	log debug "$DEVNAME does not contain a filesystem or disklabel"
    fi

elif test "$1" = remove; then

    # A block or partition device has been removed.
    # Test if it is mounted.
    while read device mountpoint fstype remainder; do
	if test "$DEVNAME" = "$device"; then
	    # If the mountpoint and filesystem type are maintained by
	    # this script, unmount the filesystem.
	    if in_list "$mountpoint" "$MOUNTPOINTS" \
		&& in_list "$fstype" "$FILESYSTEMS"; then
		log info "executing command: umount -l $mountpoint"
		umount -l "$mountpoint"

		# Run hook scripts; ignore errors.
		export UM_DEVICE="$DEVNAME"
		export UM_MOUNTPOINT="$mountpoint"
		export UM_FILESYSTEM="$fstype"
		log info "executing command: run-parts /etc/usbmount/umount.d"
		run-parts /etc/usbmount/umount.d || :
	    fi
	    lockfile-remove /var/run/.usbmount
	    break
	fi
    done < /proc/mounts

fi

exit 0