#!/bin/sh
#
# Automount hotplugged block devices, by Wout Mertens (wmertens@gentoo.org)
#
# Linux v2.6 version
# This script is released under version 2 of the GPL.

# To install this, either make it /sbin/hotplug, or, if you have
# linux-hotplug installed, make it /etc/hotplug.d/block/automount.hotplug .
# It needs to be executable. I tested it with busybox's ash.
#
# The devices will be mounted for the console user if applicable.
#
# To work, this needs:
# - v2.6 kernel support:
#   - hotplugging, /proc mounted, /sys mounted
#   - filesystems that will be mounted, like vfat
# - sh, echo, sed, stat or ls, getent or grep passwd,
#   mount, umount, mkdir, rmdir. logger is used if there.
#
# Possible improvements:
# - Create a desktop entry for the device.
# - Call a notifier script when mounting/unmounting. This could create the
#   desktop entry by itself.
# - Edit fstab instead, and give the "user" option. This depends more on
#   the user/desktop knowing what he/it is doing.
# - Mount as supermount if available. This will improve behaviour for
#   synchronous writes and hanging mounts, although umount -lf already
#   does a good job. UPDATE: added, but untested. Let me know if it works.
# - Detect filesystem on device, so filesystems that don't need a mounting
#   user can skip user detection.

#ChangeLog:
#2004-05-03: Jaromir Malenko <malenko@email.cz>
#	Minor changes
#2004-05-01: Jaromir Malenko <malenko@email.cz>
#	FIX: Supermount
#	Cleanup
#Previous changes: Wout Mertens (wmertens@gentoo.org)

# Debugging
# set -xv
# exec > /tmp/hotplug.$$ 2>&1 

PATH="/bin:/sbin:/usr/bin:/usr/sbin"
export PATH

# We only handle block device messages
[ "$1" != "block" ] && exit 0

# Proclaim stuff to the world
mesg () {
	logger -t $0 "$*"
}

# Is path already mounted?
is_path_mounted () {
	while read dev path rest
	do
		if [ "$path" = "$1" ]
		then
			return 0
		fi
	done < /proc/self/mounts
	return 1
}

# Get mounted path for a device
get_mounted_path () {
	while read dev path type rest
	do
		if [ "$type" = "supermount" ]
		then
			if echo "$rest" | grep -q "$1"
			then
				echo "$path"
				return 0
			fi
		else
			if [ "$dev" = "$1" ]
			then
				echo "$path"
				return 0
			fi
		fi
	done < /proc/self/mounts
	return 1
}

# Wait for a file to appear
wait_for () {
	local count=0
	while [ $count -lt 10 ] && [ ! -e "$1" ]
	do
		sleep 1
	done
	[ $count -eq 10 ] && return 1
	return 0
}

# Remove strange characters from a filename
clean_filename () {
	# Note the lack of quotes around $1, this strips off spaces.
	echo $1 | sed 's/[ /?*\"<>]/_/g'
}

# Figure out the device to mount
set `echo $DEVPATH | sed 's/\// /g'`
[ $# -ne 3 ] && exit 0
DEVICE=/dev/$3

case $ACTION in

remove)
	# Is it ours?
	dir=`get_mounted_path $DEVICE`
	echo "$dir" | grep -q ^/mnt/usb || exit 0

	# Unmount it
	[ -d "$dir" ] || exit 1
	mesg Unmounting: "$dir"
	umount -lf "$dir"
	rmdir "$dir"
	exit 1
	;;

add)
	# Is it a usb device? Exit if not.
	ls -l /sys/$1/$2/device | sed 's/^.* -> //g' | grep -q usb || exit 0
	
	# Mount it

	# Make sure we have support for vfat
	modprobe -q vfat

	wait_for /sys/$1/$2/device/vendor || exit 1

	# Find the name
	PRODUCT=`cat /sys/$1/$2/device/model`
	if [ -z "$PRODUCT" ]
	then
		PRODUCT=generic
	fi
	# Find out where we mount it
	MOUNTPATH=/mnt/usb/`clean_filename "$PRODUCT"`
	if is_path_mounted "$MOUNTPATH"
	then
		count=1
		while is_path_mounted "${MOUNTPATH}_${count}"
		do
			count=$(( $count + 1 ))
		done
		MOUNTPATH="${MOUNTPATH}_${count}"
	fi
	# Make sure it's a directory
	if [ -e "$MOUNTPATH" ]
	then
		if [ ! -d "$MOUNTPATH" ]
		then
			mesg "$MOUNTPATH exists but is not a directory"
			exit 1
		fi
	else
		mkdir -p "$MOUNTPATH"
		if [ $? -ne 0 ]
		then
			mesg "Could not create mountpoint $MOUNTPATH"
			exit 1
		fi
	fi
	# Find out who we are going to mount it as
	#CONSOLEUSER=`stat -c%U /dev/console 2>/dev/null`
	CONSOLEUSER=`who | grep ":0" | cut -f 1 -d " "`
	if [ -z "$CONSOLEUSER" ]
	then
		set `ls -l /dev/console`
		CONSOLEUSER=$3
	fi
	[ -n "$CONSOLEUSER" ] || CONSOLEUSER=root
	PASSWD=`getent passwd $CONSOLEUSER 2>/dev/null`
	if [ -z "$PASSWD" ]
	then
		PASSWD=`grep "^$CONSOLEUSER:" /etc/passwd || grep "^root:" /etc/passwd`
	fi
	if [ -z "$PASSWD" ]
	then
		mesg "Could not get password entry for $CONSOLEUSER nor root"
		exit 1
	fi
	set `echo $PASSWD | sed 's/:/ /g'`
	if [ $# -lt 4 ]
	then
		mesg "Bad password entry for $CONSOLEUSER"
		exit 1
	fi

	# These options should prevent abuse and make it writeable for the
	# console user.
	if grep -q supermount /proc/filesystems
	then
		MOUNTOPTS="-s -t supermount -odev=$DEVICE,fs=auto,--,noatime,nosuid,umask=077,uid=$3,gid=$4"
		DEVICE="none"
	else
		MOUNTOPTS="-s -onoatime,sync,dirsync,nosuid,umask=007,uid=$3,gid=$4"
	fi
	mesg Mounting $DEVICE on $MOUNTPATH, options $MOUNTOPTS

	mount $MOUNTOPTS $DEVICE $MOUNTPATH
	;;
	
*)
	mesg automount.hotplug $ACTION event not supported
	exit 1
	;;
esac