#!/bin/sh
set -eu

version="${1-}"
kdumpdir="/var/lib/kdump"

[ -x /usr/sbin/mkinitramfs ] || exit 0

# passing the kernel version is required
if [ -z "${version}" ]; then
	echo >&2 "W: kdump-tools: ${DPKG_MAINTSCRIPT_PACKAGE:-kdump-tools package} did not pass a version number"
	exit 2
fi

if ! linux-version list | grep "${version}" > /dev/null ; then
	exit 0
fi

# exit if kernel does not need an initramfs
if [ "${INITRD-}" = 'No' ]; then
	exit 0
fi

# initramfs generation may fail, or include an inappropriate set of kernel
# modules in a chroot. Leave it to the target system to handle on reboot
if [ -x "$(command -v ischroot)" ] && ischroot; then
	echo "W: kdump-tools: Executing in a chroot, skipping initramfs generation." >&2
	exit 0;
fi

# avoid running multiple times
if [ -n "${DEB_MAINT_PARAMS-}" ]; then
	eval set -- "$DEB_MAINT_PARAMS"
	if [ -z "$1" ] || [ "$1" != "configure" ]; then
		exit 0
	fi
fi

if test ! -e /etc/initramfs-tools/initramfs.conf; then
	echo "W: kdump-tools: /etc/initramfs-tools/initramfs.conf is missing." >&2
	exit 2
fi
. /etc/initramfs-tools/initramfs.conf
for conf_file in /etc/initramfs-tools/conf.d/*; do
	if test -f "$conf_file" && basename "$conf_file" | grep '^[[:alnum:]][[:alnum:]\._-]*$' | grep -qv '\.dpkg-.*$'; then
		. "$conf_file"
	fi
done

if test "${MODULES-most}" = most; then
	# Switch from "most" to "dep" to reduce the size of the initramfs.
	# "netboot" and "list" are expected to be already small enough.
	KDUMP_MODULES=dep
fi

# We need a modified copy of initramfs-tools directory
# with MODULES=dep in initramfs.conf
if [ ! -d "$kdumpdir" ];then
	mkdir -p "$kdumpdir"
fi
# Force re-creation of $kdumpdir/initramfs-tools
# in case the source has changed since last time
# we ran
if [ -d "$kdumpdir/initramfs-tools" ];then
	rm -Rf $kdumpdir/initramfs-tools
fi
cp -pr /etc/initramfs-tools "$kdumpdir"

initramfsdir="$kdumpdir/initramfs-tools"

if test -n "${KDUMP_MODULES-}" -a "${KDUMP_MODULES-}" != "${MODULES}"; then
	mkdir -p "$initramfsdir/conf.d"
	echo "MODULES=${KDUMP_MODULES}" > "$initramfsdir/conf.d/zzz-kdump"
fi

# Add scsi_dh_* modules if in use otherwise
# kexec reboot on multipath will fail
# (LP: #1635597)
for I in $(lsmod | grep scsi_dh | cut -d" " -f1);do
	echo "${I}" >> $initramfsdir/modules
done

#Add makedump scripts/init-bottom
tee $initramfsdir/scripts/init-bottom/makedump 1> /dev/null << EOF
#!/bin/sh

PREREQ=""

prereqs()
{
        echo "\${PREREQ}"
}

case \${1} in
        prereqs)
                prereqs
                exit 0
                ;;
esac

#Check if VMCORE is available
if [ ! -f /proc/vmcore ]; then
        exit 0
fi

. /scripts/functions
. /scripts/local

log_end_msg
log_begin_msg "mounting  \${ROOT} over \${rootmnt}"
sleep 2
log_end_msg
mount -o remount,rw,relatime,errors=remount-ro \${ROOT} \${rootmnt}

log_begin_msg "Dumping the crashed kernel"
log_end_msg

KDUMP_DEFAULTS=\${rootmnt}/etc/default/kdump-tools
[ -r \$KDUMP_DEFAULTS ] && . \$KDUMP_DEFAULTS

mkdir -p \${rootmnt}/var/crash
rm -fr /var/crash
ln -s \${rootmnt}/var/crash /var/crash

KDUMP_COREDIR=\${KDUMP_COREDIR:=/var/crash}
KDUMP_SKIP_VMCORE=\${KDUMP_SKIP_VMCORE:=1}
KDUMP_DUMP_DMESG=\${KDUMP_DUMP_DMESG:=1}
KDUMP_NUM_DUMPS=\${KDUMP_NUM_DUMPS:=0}
MAKEDUMP_ARGS=\${MAKEDUMP_ARGS:="-c -d 31"}


IOMEM_ADDR=\`grep -i "Crash kernel" /proc/iomem | sed "s/-..*//" | sed "s/^[ 0]*/0x/"\`
vmcore_file=/proc/vmcore

KDUMP_STAMP=\`date +"%Y%m%d%H%M"\`
KDUMP_STAMPDIR="\$KDUMP_COREDIR/\$KDUMP_STAMP"
if [ -d \$KDUMP_STAMPDIR ]; then
	log_failure_msg "Directory \$KDUMP_STAMPDIR already exist"
	exit 1
fi

mkdir -p \$KDUMP_STAMPDIR
KDUMP_COREFILE="\$KDUMP_STAMPDIR/dump.\$KDUMP_STAMP"
KDUMP_DMESGFILE="\$KDUMP_STAMPDIR/dmesg.\$KDUMP_STAMP"

if [ "\$KDUMP_DUMP_DMESG" -eq 1 ] ; then
        log_begin_msg "running makedumpfile --dump-dmesg \$vmcore file \$KDUMP_DMESGFILE"
        sleep 2
        log_end_msg
        makedumpfile --dump-dmesg \$vmcore_file \$KDUMP_DMESGFILE
fi

if [ "\$KDUMP_SKIP_VMCORE" -ne 1 ]; then
        log_begin_msg "running makedumpfile \$MAKEDUMP_ARGS \$vmcore_file \$KDUMP_COREFILE"
        sleep 2
        log_end_msg
        makedumpfile \$MAKEDUMP_ARGS \$vmcore_file \$KDUMP_COREFILE
fi

sync
umount \${rootmnt} 2> /dev/null

log_success_msg "Rebooting system"
sleep 2

echo 1 > /proc/sys/kernel/sysrq
echo b > /proc/sysrq-trigger
EOF
chmod 755 $initramfsdir/scripts/init-bottom/makedump

# Add makedump hooks
tee $initramfsdir/hooks/makedump 1> /dev/null << EOF
#!/bin/sh

PREREQ=""

prereqs()
{
        echo "\$PREREQ"
}

case \$1 in
prereqs)
        prereqs
        exit 0
        ;;
esac

if [ ! -x /usr/bin/makedumpfile ]; then
        exit 0
fi

. /usr/share/initramfs-tools/scripts/functions
. /usr/share/initramfs-tools/hook-functions

copy_exec /usr/bin/makedumpfile
EOF
chmod 755 $initramfsdir/hooks/makedump

# Add cleanup hooks
tee $initramfsdir/hooks/cleanup 1> /dev/null << EOF
#!/bin/sh

PREREQ=""

prereqs()
{
        echo "\$PREREQ"
}

case \$1 in
prereqs)
        prereqs
        exit 0
        ;;
esac

. /usr/share/initramfs-tools/scripts/functions
. /usr/share/initramfs-tools/hook-functions

rm -fr \${DESTDIR}/lib/modules/\${version}/kernel/drivers/gpu
rm -fr \${DESTDIR}/lib/modules/\${version}/kernel/drivers/video
rm -fr \${DESTDIR}/lib/modules/\${version}/kernel/drivers/vfio
rm -fr \${DESTDIR}/lib/modules/\${version}/updates/dkms/nvidia*
rm -fr \${DESTDIR}/lib/firmware/amdgpu
rm -fr \${DESTDIR}/lib/firmware/cxgb*
rm -fr \${DESTDIR}/lib/firmware/radeon
EOF
chmod 755 $initramfsdir/hooks/cleanup

sed -e 's/MODULES=.*/MODULES=dep/' /etc/initramfs-tools/initramfs.conf > "$initramfsdir/initramfs.conf" || true
if ! [ -e "$initramfsdir/initramfs.conf" ];then
	echo >&2 "W: kdump-tools: Unable to create $initramfsdir/initramfs.conf"
	exit 2
fi

# Mark our custom initramfs.conf to indicate that kdump-tools
# hooks/scripts should run/get included in our minimal initrd.
#
# Unfortunately, this is not true for Debian. OPTION=VAR is a
# control provided only by Ubuntu initramfs-tools, so this is
# innocuous /harmless on Debian - kept here for better code
# sync between Debian and Ubuntu. We needed special checks on
# hook/script in Debian to prevent them on regular initrd.
echo "KDUMP=y" >> $initramfsdir/initramfs.conf

# Cleaning up existing initramfs with same version
# as mkinitramfs do not have a force option
if [ -e "$kdumpdir/initrd.img-${version}" ];then
	rm -f "$kdumpdir/initrd.img-${version}"
fi

# we're good - create initramfs.
echo "kdump-tools: Generating $kdumpdir/initrd.img-${version}"

INITRD_TMPDIR="$(mktemp -d)"
INITRD_FNAME="initrd.img-${version}"
INITRD_CMDLINE=" -k -d ${initramfsdir} -o ${kdumpdir}/${INITRD_FNAME}.new ${version}"

# NB: we *want* to split on spaces in INITRD_CMDLINE, so disable this check here
# shellcheck disable=SC2086
if TMPDIR=${INITRD_TMPDIR} mkinitramfs ${INITRD_CMDLINE} 1>/dev/null; then
	mv "${kdumpdir}/${INITRD_FNAME}.new" "${kdumpdir}/${INITRD_FNAME}"

	# Retain the initrd decompressed size in order potential users (like
	# kdump memory estimator) are able to use that in calculations.
	INITRD_DECOMPRESSED=$(find "${INITRD_TMPDIR}" -maxdepth 1 ! -path "${INITRD_TMPDIR}" -type d)

	if [ -d "${INITRD_DECOMPRESSED}" ]; then
		du -sm "${INITRD_DECOMPRESSED}" | awk '{print $1}' > "${kdumpdir}/size_${INITRD_FNAME}"
		sync "${kdumpdir}/size_${INITRD_FNAME}"
	fi
	rm -rf "${INITRD_TMPDIR}"
else
	mkinitramfs_return="$?"
	rm -f "$kdumpdir/initrd.img-${version}.new"
	echo "update-initramfs: failed for $kdumpdir/initrd.img-${version} with $mkinitramfs_return." >&2
	rm -rf "${INITRD_TMPDIR}"
	exit $mkinitramfs_return
fi