#!/bin/bash

KERNEL="unknown"
INITRD="unknown"
TD=""


# init needs /selinux to be there
check_dir()
{
	SLDIR="/selinux"

	if [ -d $SLDIR ];then
		printf "\tcheck_dir: OK. $SLDIR exists.\n"
		return 0
	else
		printf "\tcheck_dir: ERR. $SLDIR does not exists, please execute 'mkdir $SLDIR' as root.\n"
		return 1
	fi
}

check_filesystem()
{
	FSPATH="/proc/filesystems"
	FSNAME="selinuxfs"

	grep -w $FSNAME $FSPATH 1>&2 >/dev/null

	if [ $? == 0 ]; then
		printf "\tcheck_filesystem: OK. Filesystem '$FSNAME' exists.\n"
		return 0
	else
		printf "\tcheck_filesystem: ERR. Filesystem '$FSNAME' is missing. Please enable SELinux while compiling the kernel.\n"
		return 0
	fi
}

check_boot()
{
	BPARAM="security=selinux.*selinux=1.*enforcing=?"  # XXX order not mandatory

	printf "\tcheck_boot: Assuming GRUB as bootloader.\n"

	BLINE=$(grep -E $BPARAM /boot/grub/menu.lst 2>/dev/null) # XXX check for multiple lines in config

	if [ $? == 0 ]; then
		K=$(echo $BLINE | awk -F' ' '{print $2}')
		KERNEL=$(basename $K)
		K=$(echo $KERNEL | sed s/vmlinuz-//)
		INITRD=initrd-$K
		printf "\tcheck_boot: OK. Kernel '$KERNEL' has boot-parameter '$BPARAM'\n"
		return 0
	else
		printf "\tcheck_boot: ERR. Boot-parameter missing for booting the kernel.\n"
		printf "\t            Please use YaST2 to add 'selinux=1' to the kernel boot-parameter list.\n"
		return 1
	fi
}

check_mkinitrd()
{
	MCMD="mount.*/root/proc.*"

	if ! [ -f "/boot/$INITRD" ];then
		printf "\tcheck_mkinitrd: ERR. Unable to locate '/boot/$INITRD'\n"
		return 2
	fi

	cp /boot/$INITRD $TD/i.cpio.gz 2>/dev/null

	if ! [ -f "$TD/i.cpio.gz" ];then
		printf "\tcheck_mkinitrd: ERR. Error while copying initrd file.'\n"
		return 2
	fi


	pushd . 2>&1>/dev/null
	cd $TD
	mkdir initrd-extracted
	cd initrd-extracted
	gunzip -c $TD/i.cpio.gz | cpio -i --force-local --no-absolute-filenames 2>/dev/null
	grep -E -- $MCMD boot/* 2>&1 >/dev/null
	FLG=$?
	popd 2>&1>/dev/null

	if [ $FLG == 0 ];then
		printf "\tcheck_mkinitrd: OK. Your initrd seems to be correct.\n"
		return 0
	else
		printf "\tcheck_mkinitrd: ERR. Your initrd seems not to mount /proc of\n"
		printf "\t                the root filesystem during boot, this may be a\n"
		printf "\t                reason for SELinux not working.\n"
		return 1
	fi
}

check_packages()
{
	PKGLST="checkpolicy policycoreutils selinux-tools libselinux1 libsepol1 libsemanage1 selinux-policy"
	FAIL=0

	for i in $PKGLST
	do
		rpm -q $i 1>&2 >/dev/null
		if [ $? == 1 ];then
			printf "\tcheck_packages: ERR. Package '$i' not installed, please run 'zypper in $i' as root\n"
			FAIL=1
		fi
	done

	if [ $FAIL == 0 ]; then
		printf "\tcheck_packages: OK. All essential packages are installed\n"
		return 0
	else
		return 1
	fi
}

check_config()
{
	CF="/etc/selinux/config"

	if [ -f $CF ];then
		printf "\tcheck_config: OK. Config file seems to be there.\n"
		return 0
	else
		printf "\tcheck_config: ERR. Config file '$CF' is missing.\n"
		return 1
	fi
}

TD=$(mktemp -q -d /tmp/selinux-ready.XXXXXX)

echo "Start checking your system if it is selinux-ready or not:"
check_dir
check_filesystem
check_boot
check_mkinitrd
check_packages
check_config

rm -rf $TD