#!/bin/sh
# This script mounts USB mass storage devices when they are plugged in
# and unmounts them when they are removed.
# Copyright © 2004, 2005 Martin Dickopp
# Copyright © 2008, 2009, 2010 Rogério Theodoro de Brito
#
# 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

######################################################################
# Auxiliary functions

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


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


######################################################################
# Main program

# Default values for configuration variables.
ENABLED=1
MOUNTPOINTS=
FILESYSTEMS=
MOUNTOPTIONS=
FS_MOUNTOPTIONS=
VERBOSE=no

if [ -r /etc/usbmount/usbmount.conf ]; then
    . /etc/usbmount/usbmount.conf
    log debug "loaded usbmount configurations"
fi

if [ "${ENABLED:-1}" -eq 0 ]; then
    log info "usbmount is disabled, see /etc/usbmount/usbmount.conf"
    exit 0
fi

# Per Policy 9.3.2, directories under /var/run have to be created
# after every reboot.
if [ ! -e /var/run/usbmount ]; then
    mkdir -p /var/run/usbmount
    log debug "creating /var/run/usbmount directory"
fi

umask 022


if [ "$1" = add ]; then

    # Acquire lock.
    log debug "trying to acquire lock /var/run/usbmount/.mount.lock"
    lockfile-create --retry 3 /var/run/usbmount/.mount || \
	{ log err "cannot acquire lock /var/run/usbmount/.mount.lock"; exit 1; }
    trap '( lockfile-remove /var/run/usbmount/.mount )' 0
    log debug "acquired lock /var/run/usbmount/.mount.lock"

    if ! echo $ID_FS_USAGE | egrep -q "(filesystem|disklabel)"; then
	log info "$DEVNAME does not contain a filesystem or disklabel"
	exit 1
    fi

    # Try to use specifications in /etc/fstab first.
    if egrep -q "^[[:blank:]]*$DEVNAME" /etc/fstab; then
	log info "executing command: mount $DEVNAME"
	mount $DEVNAME || log err "mount by DEVNAME with $DEVNAME wasn't successful; return code $?"

    elif grep -q "^[[:blank:]]*UUID=$ID_FS_UUID" /etc/fstab; then
        log info "executing command: mount -U $ID_FS_UUID"
	mount -U $ID_FS_UUID || log err "mount by UUID with $ID_FS_UUID wasn't successful; return code $?"

    else
	log debug "$DEVNAME contains filesystem type $ID_FS_TYPE"

	fstype=$ID_FS_TYPE
	# Test if the filesystem type is in the list of filesystem
	# types to mount.
	if in_list "$fstype" "$FILESYSTEMS"; then
	    # Search an available mountpoint.
	    for v in $MOUNTPOINTS; do
		if [ -d "$v" ] && ! grep -q "^[^ ][^ ]*  *$v " /proc/mounts; then
		    mountpoint="$v"
		    log debug "mountpoint $mountpoint is available for $DEVNAME"
		    break
		fi
	    done
	    if [ -n "$mountpoint" ]; then
		# Determine mount options.
		options=
		for v in $FS_MOUNTOPTIONS; do
		    if expr "$v" : "-fstype=$fstype,."; then
			options="$(echo "$v" | sed 's/^[^,]*,//')"
			break
		    fi
		done
		if [ -n "$MOUNTOPTIONS" ]; then
		    options="$MOUNTOPTIONS${options:+,$options}"
		fi

		# Mount the filesystem.
		log info "executing command: mount -t$fstype ${options:+-o$options} $DEVNAME $mountpoint"
		/recalbox/scripts/recalbox-mount.sh "$fstype" 0 "${DEVNAME}" "${mountpoint}"

		# Determine vendor and model.
		vendor=
		if [ -r "/sys$DEVPATH/device/vendor" ]; then
		    vendor="`cat \"/sys$DEVPATH/device/vendor\"`"
		elif [ -r "/sys$DEVPATH/../device/vendor" ]; then
		    vendor="`cat \"/sys$DEVPATH/../device/vendor\"`"
		elif [ -r "/sys$DEVPATH/device/../manufacturer" ]; then
		    vendor="`cat \"/sys$DEVPATH/device/../manufacturer\"`"
		elif [ -r "/sys$DEVPATH/../device/../manufacturer" ]; then
		    vendor="`cat \"/sys$DEVPATH/../device/../manufacturer\"`"
		fi
		vendor="$(echo "$vendor" | sed 's/^[[:blank:]]\+//; s/[[:blank:]]\+$//')"

		model=
		if [ -r "/sys$DEVPATH/device/model" ]; then
		    model="`cat \"/sys$DEVPATH/device/model\"`"
		elif [ -r "/sys$DEVPATH/../device/model" ]; then
		    model="`cat \"/sys$DEVPATH/../device/model\"`"
		elif [ -r "/sys$DEVPATH/device/../product" ]; then
		    model="`cat \"/sys$DEVPATH/device/../product\"`"
		elif [ -r "/sys$DEVPATH/../device/../product" ]; then
		    model="`cat \"/sys$DEVPATH/../device/../product\"`"
		fi
		model="$(echo "$model" | sed 's/^[[:blank:]]\+//; s/[[:blank:]]\+$//')"

		# Run hook scripts; ignore errors.
		export UM_DEVICE="$DEVNAME"
		export UM_UUID="$ID_FS_UUID"
		export UM_MOUNTPOINT="$mountpoint"
		export UM_FILESYSTEM="$fstype"
		export UM_MOUNTOPTIONS="$options"
		export UM_VENDOR="$vendor"
		export UM_MODEL="$model"
		export UM_LABEL="$ID_FS_LABEL"
		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
    fi
elif [ "$1" = remove ]; then

    # A block or partition device has been removed.
    # Test if it is mounted.
    while read device mountpoint fstype remainder; do
	if [ "$DEVNAME" = "$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
	    break
	fi
    done < /proc/mounts
else
    log err "unexpected: action '$1'"
    exit 1
fi

log debug "usbmount execution finished"
