#!/bin/sh -e
# Copyright 2008 Tobias Tacke, all rights reserved.
# This program is free software; you can redistribute it and/or modify it under the GPL-terms (http://dev.perl.org/licenses/gpl1.html)

_assert_not_run() {
	if _is_mount_remain ; then
		echo "Error: some mounts still exists"
		exit 1
	fi
	if _is_skelett_remain ; then
		echo "Error: some parts of /.disk2ram - skelett still exists"
		exit 1
	fi
	return 0
}
_assert_run_complete() {
	if ! _is_skelett_complete ; then
		echo "Error: /.disk2ram - skelett is'n complete"
		exit 1
	fi
	if ! _is_mount_complete ; then
		echo "Error: mounts are incomplete"
		exit 1
	fi
	return 0
}
_sync_to_state() {
	rsync -cav --delete --exclude=/lib/dpkg --exclude=/lib/apt --exclude=/cache --exclude=/run --exclude=/lock /.disk2ram/var.volatile/ /.disk2ram/var.state/ || return 1
	rsync -cav --delete /.disk2ram/tmp.volatile/ /.disk2ram/tmp.state/ || return 1
	return 0
}
_sync_to_volatile() {
	rsync -a --exclude=/lib/dpkg --exclude=/lib/apt --exclude=/cache --exclude=/run --exclude=/lock /.disk2ram/var.state/ /.disk2ram/var.volatile/ || return 1
	mkdir /.disk2ram/var.volatile/run || return 1
	mkdir /.disk2ram/var.volatile/lock || return 1
	rsync -a /.disk2ram/tmp.state/ /.disk2ram/tmp.volatile/ || return 1
	return 0
}
_mount() {
	mount -t tmpfs -o size=1024M -o sync -o dirsync -o mode=0755 -o rw -o nosuid -o nodev -o noauto disk2ram.var /.disk2ram/var.volatile || return 1
	mount -t tmpfs -o size=256M -o sync -o dirsync -o mode=1777 -o rw -o nosuid -o nodev -o noauto disk2ram.tmp /.disk2ram/tmp.volatile || return 1
	
	mount -o bind /var /.disk2ram/var.state || return 1

	# external binds
	mount -o bind /media/sicher/www /.disk2ram/var.state/www || return 1
	mount -o bind /media/sicher/mysql /.disk2ram/var.state/lib/mysql || return 1
	mount -o bind /media/sicher/log /.disk2ram/var.state/log || return 1
	# Disabled! Not very clever to have multiple tmps
	# mount -o bind /media/sicher/vartmp /.disk2ram/var.state/tmp || return 1
	# mount -o bind /media/sicher/tmp /tmp || return 1

	mount -o bind /tmp /.disk2ram/tmp.state || return 1

	_sync_to_volatile || return 1

	mount -o bind /var/run /.disk2ram/var.state/run || return 1
	mount -o bind /var/lock /.disk2ram/var.state/lock || return 1
	umount -l /var/lock || return 1
	umount -l /var/run || return 1

	ln -s /.disk2ram/var.state/cache/ /.disk2ram/var.volatile/cache || return 1
	ln -s /.disk2ram/var.state/lib/apt/ /.disk2ram/var.volatile/lib/apt || return 1
	ln -s /.disk2ram/var.state/lib/dpkg/ /.disk2ram/var.volatile/lib/dpkg || return 1
	
	mount -o bind /.disk2ram/var.volatile /var || return 1
	mount -o bind /.disk2ram/var.state/run /var/run || return 1
	mount -o bind /.disk2ram/var.state/lock /var/lock || return 1
	
	mount -o bind /.disk2ram/tmp.volatile /tmp || return 1
	
	return 0
}
_force_unmount() {
	# external binds
	umount -l /.disk2ram/var.state/www
	umount -l /.disk2ram/var.state/lib/mysql
	umount -l /.disk2ram/var.state/log

	umount -l /tmp
	umount -l /.disk2ram/tmp.state
	umount -l /.disk2ram/tmp.volatile
	umount -l /var
	umount -l /.disk2ram/var.state
	umount -l /.disk2ram/var.volatile
}
_unmount() {
	_sync_to_state || return 1

	umount -l /var/lock || return 1
	umount -l /var/run || return 1
	umount -l /var || return 1

	mount -o bind /.disk2ram/var.state/run /var/run || return 1
	mount -o bind /.disk2ram/var.state/lock /var/lock || return 1
	
	umount -l /.disk2ram/var.state/lock || return 1
	umount -l /.disk2ram/var.state/run || return 1

	# external binds
	umount -l /.disk2ram/var.state/www || return 1
	umount -l /.disk2ram/var.state/lib/mysql || return 1
	umount  -l /.disk2ram/var.state/log || return 1

	umount -l /.disk2ram/var.state || return 1
	umount -l /.disk2ram/var.volatile || return 1
	
	umount -l /tmp || return 1
	umount -l /.disk2ram/tmp.state || return 1
	umount -l /.disk2ram/tmp.volatile || return 1
	return 0
}
_create_skelett() {
	mkdir /.disk2ram || return
	mkdir /.disk2ram/var.state || return 1
	mkdir /.disk2ram/var.volatile || return 1
	mkdir /.disk2ram/tmp.state || return 1
	mkdir /.disk2ram/tmp.volatile || return 1
	return 0
}
_remove_skelett() {
	rmdir /.disk2ram/var.state/ || return 1
	rmdir /.disk2ram/var.volatile/ || return 1
	rmdir /.disk2ram/tmp.state/ || return 1
	rmdir /.disk2ram/tmp.volatile/ || return 1
	rmdir /.disk2ram/ || return 1
	return 0
}
_force_remove_skelett() {
	rmdir /.disk2ram/var.state/
	rmdir /.disk2ram/var.volatile/
	rmdir /.disk2ram/tmp.state/
	rmdir /.disk2ram/tmp.volatile/
	rmdir /.disk2ram/
	return 0
}
_is_mount_complete() {
	# external binds
	grep '/media/sicher/www /.disk2ram/var.state/www' /etc/mtab 1> /dev/null || return 1
	grep '/media/sicher/mysql /.disk2ram/var.state/lib/mysql' /etc/mtab 1> /dev/null || return 1
	grep '/media/sicher/log /.disk2ram/var.state/log' /etc/mtab 1> /dev/null || return 1
	grep 'disk2ram.var /.disk2ram/var.volatile tmpfs ' /etc/mtab 1> /dev/null || return 1
	grep '/var /.disk2ram/var.state none ' /etc/mtab 1> /dev/null || return 1
	grep '/.disk2ram/var.volatile /var none ' /etc/mtab 1> /dev/null || return 1
	grep 'disk2ram.tmp /.disk2ram/tmp.volatile tmpfs ' /etc/mtab 1> /dev/null || return 1
	grep '/tmp /.disk2ram/tmp.state none ' /etc/mtab 1> /dev/null || return 1
	grep '/.disk2ram/tmp.volatile /tmp none ' /etc/mtab 1> /dev/null || return 1
	
	return 0
}
_is_mount_remain() {
	# external binds
	grep '/media/sicher/www /.disk2ram/var.state/www' /etc/mtab 1> /dev/null && return 0
	grep '/media/sicher/mysql /.disk2ram/var.state/lib/mysql' /etc/mtab 1> /dev/null && return 0
	grep '/media/sicher/log /.disk2ram/var.state/log' /etc/mtab 1> /dev/null && return 0

	grep 'disk2ram.var /.disk2ram/var.volatile tmpfs ' /etc/mtab 1> /dev/null && return 0
	grep '/var /.disk2ram/var.state none ' /etc/mtab 1> /dev/null && return 0
	grep '/.disk2ram/var.volatile /var none ' /etc/mtab 1> /dev/null && return 0
	
	grep 'disk2ram.tmp /.disk2ram/tmp.volatile tmpfs ' /etc/mtab 1> /dev/null && return 0
	grep '/tmp /.disk2ram/tmp.state none ' /etc/mtab 1> /dev/null && return 0
	grep '/.disk2ram/tmp.volatile /tmp none ' /etc/mtab 1> /dev/null && return 0
	
    return 1
}
_is_skelett_complete() {
    [ -d /.disk2ram ] || return 1
    [ -d /.disk2ram/var.state ] || return 1
    [ -d /.disk2ram/var.volatile ] || return 1
    [ -d /.disk2ram/tmp.state ] || return 1
    [ -d /.disk2ram/tmp.volatile ] || return 1
    return 0
}
_is_skelett_remain() {
    [ -d /.disk2ram ] && return 0
    [ -d /.disk2ram/var.state ] && return 0
    [ -d /.disk2ram/var.volatile ] && return 0
    [ -d /.disk2ram/tmp.state ] && return 0
    [ -d /.disk2ram/tmp.volatile ] && return 0
    return 1
}
_stop_all_jobs() {
	service apparmor stop
	echo "Stop all jobs..."
	perl -e "
		use strict;
		use warnings;
		
		my \$USED_JOBS = {
			apache2		=> 'apache2',
			openvpn		=> 'openvpn',
			cron		=> 'cron',
			atd		=> 'atd',
			rsyslogd	=> 'rsyslog',
			mysqld		=> 'mysql',
			dbus		=> 'dbus',
			ddclient	=> 'KILL',
			acpid		=> 'acpid',
			dhclient3	=> 'KILL',
			php5		=> 'SLEEP',
		};
		if(!_stop_all()) {
			print \"failed\";
			exit(1);
		}
		
		sub _get_running_jobs {
			\$| = 1;
			open(FH, '-|', 'lsof|grep \' /var\'');
			my \$jobs = {};
			while(my \$line = <FH>) {
				my @line = split(/\W/, \$line);
				next if(\$line[0] eq \"init\" && \$line =~ m/\/var\/log\/upstart\//);
				
				\$jobs->{\$line[0]} = 1;
			}
			close(FH);
			return keys(%\$jobs);
	}
	sub _exec {
			my (\$job, \$cmd) = @_;
			
			my \$job_name = \$USED_JOBS->{\$job};
			my \$command = \"service \$job_name \$cmd\";
			if(\$job_name eq 'KILL') {
				\$command = \"killall -r \$job\";
			} elsif(\$job_name eq 'SLEEP') {
				\$command = \"sleep 10\";
			} elsif(\$job eq 'dhclient3') {
				\$command = \"dhclient3 -e IF_METRIC=100 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0 -r -x\";
			}
			print \"\n\$cmd \$job: \$command ... \";
			my \$result = system(\$command) ? 0 : 1;
			print ' ... ' . (\$result ? 'done' : 'FAILED!') . \"\n\";
			return \$result;
		}
		sub _stop_all {
			my \$failed = 0;
			foreach my \$name (_get_running_jobs()) {
				if(!_exec(\$name, 'stop')) {
					\$failed = 1;
				}
			}
			foreach my \$name (_get_running_jobs()) {
				print \"process \$name is still running! Please stop it!!!\n\";
				\$failed = 1;
			}
			return 0 if(\$failed);
			
			return 1;
		}
	" || exit 1
		
	echo "...done"
	return 0
}
_start_all_jobs() {
	echo "Start all jobs..."
	perl -e "
		use strict;
		use warnings;
		
		my \$USED_JOBS = {
			apache2		=> 'apache2',
			openvpn		=> 'openvpn',
			cron		=> 'cron',
			atd		=> 'atd',
			rsyslogd	=> 'rsyslog',
			mysqld		=> 'mysql',
			dbus		=> 'dbus',
			ddclient	=> 'ddclient',
			acpid		=> 'acpid',
			dhclient3	=> 1,
		};
		if(!_start_all()) {
			print \"failed\";
			exit(1);
		}
		sub _exec {
			my (\$job, \$cmd) = @_;
			
			my \$job_name = \$USED_JOBS->{\$job};
			my \$command = \"service \$job_name \$cmd\";
			print \"\n\$cmd \$job: \$command ... \";
			# START
			if(\$job eq \"dhclient3\") {
				\$command = \"dhclient3 -e IF_METRIC=100 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0\";
			}
			my \$result = system(\$command) ? 0 : 1;
			print ' ... ' . (\$result ? 'done' : 'FAILED!') . \"\n\";
			return \$result;
		}
		sub _start_all {
			my \$failed = 0;
			my %all_jobs = %\$USED_JOBS;
			foreach my \$name (keys(%all_jobs)) {
				if(!_exec(\$name, 'start')) {
					if(!_exec(\$name, 'restart')) {
						\$failed = 1;
					}
				}
			}
			return 0 if(\$failed);
			
			return 1;
		
		}
	" || exit 1
		
	echo "...done"
	return 0
	service apparmor start
}
_is_external_cryptdisk_mounted() {
	grep '/dev/mapper/sdb1_crypt /media/sicher' /etc/mtab 1> /dev/null && return 0
	return 1
}
_mount_external_cryptdisk() {
	cryptdisks_start sdb1_crypt || return 1
	mount /media/sicher || return 1
	return 0
}
_handle_external_cryptdisk() {
	if _is_external_cryptdisk_mounted ; then
		echo "cryptdisk is already mounted"
		return 0
	fi
	echo "mounting cryptdisk..."
	if _mount_external_cryptdisk ; then
		echo "...done"
		return 0;
	fi
	echo "failed"
	exit 1
}

echo "disk2ram $1 ..."
case $1 in
	status)
		if _is_mount_complete && _is_skelett_complete ; then
			echo "started"
			exit 0
		fi
		if ! _is_skelett_remain && ! _is_mount_remain ; then
			echo "stopped"
			exit 0
		fi
		echo "corrupt"
		exit 1
	;;
	start)
		if _is_mount_complete && _is_skelett_complete ; then
			echo "Nothing to do. Still started"
			exit 0
		fi
		_assert_not_run
		_handle_external_cryptdisk
		if ! _create_skelett ; then
			echo "Error: can't create skelett"
			exit 1
		fi
		_stop_all_jobs
		if ! _mount ; then
			echo "Error: can't mount"
			exit 1
		fi
		_assert_run_complete
		_start_all_jobs
		echo "started"
	;;
	sync)
		if ! _is_mount_complete || ! _is_skelett_complete ; then
			echo "Error: disk2ram is not correct running. Sync without correct state is dangerous! Perform manual sync if you like (remove option '-n' to execute)"
			echo "	rsync -xcav -n --delete --exclude=/lib/dpkg --exclude=/lib/apt --exclude=/cache --exclude=/run --exclude=/lock /.disk2ram/var.volatile/ /.disk2ram/var.state/"
			echo "	rsync -xcav -n --delete /.disk2ram/tmp.volatile/ /.disk2ram/tmp.state/"
			exit 1
		fi
		_stop_all_jobs
		_sync_to_state
		_start_all_jobs
	;;
	stop)
		if ! _is_skelett_remain && ! _is_mount_remain ; then
			echo "Nothing to do. Still stopped"
			exit 0
		fi
		_assert_run_complete
		_stop_all_jobs
		_sync_to_state
		if ! _unmount ; then
			echo "Error: can't unmount"
			exit 1
		fi
		if ! _remove_skelett ; then
			echo "Error: can't remove skelett"
			exit 1
		fi
		_assert_not_run
		_start_all_jobs
		echo "stopped"
	;;
	restart|reload|force-reload)
		echo "Error: argument '$1' not supported"
		exit 3
	;;
	force-umount)
		if [ "$2" != 'do-it' ] ; then
			echo "Warning: that will result in loss of data! Say: '/etc/init.d/disk2ram force-umount do-it' to execute this"
			exit 3
		fi
		_force_unmount
	;;
	force-remove_skelett)
		if [ "$2" != 'do-it' ] ; then
			echo "Warning: that will result in loss of data! Say: '/etc/init.d/disk2ram force-remove_skelett do-it' to execute this"
			exit 3
		fi
		_force_remove_skelett
	;;

	*)
		echo "Usage: /etc/init.d/disk2ram {start|stop|status|sync|force-remove_skelett|force-umount}"
		exit 3
	;;
esac
exit 0