#!/bin/bash
#
# 10-zfcpdump.install - Installation script to handle zfcpdump kernels
#
# Copyright IBM Corp. 2018
#
# s390-tools is free software; you can redistribute it and/or modify
# it under the terms of the MIT license. See LICENSE for details.
#
#
# This script supports two modes:
#
#  1) Installing the images to /boot/<machine-id>/<kernel-version>
#     subdirectories, i.e. BOOT_DIR_ABS, as recommended by the BLS.
#     In this case file names are taken over from the original files.
#
#  2) Installing the images directly to /boot. In this case the files are
#     renamed to <original-name>-<kernel-version>.
#
# The existence of BOOT_DIR_ABS is taken as trigger to switch between both
# modes.
#
# The KERNEL_VERSION is assumed to contain '@flavor@' to identify the image
# as a zfcpdump kernel.

COMMAND="$1"
KERNEL_VERSION="$2"
BOOT_DIR_ABS="$3"
KERNEL_IMAGE="$4"

# Location zipl looks for the zfcpdump kernel
ZFCPDUMP_IMAGE='@zfcpdump_image@'

# Only handle zfcpdump kernels
echo "$KERNEL_VERSION" | grep -q '@flavor@' || exit 0

case "$COMMAND" in
	add)
		KERNEL_DIR="$(dirname $KERNEL_IMAGE)"
		KERNEL_NAME="$(basename $KERNEL_IMAGE)"

		for f in \
			"$KERNEL_IMAGE" \
			"$KERNEL_DIR"/System.map \
			"$KERNEL_DIR"/config \
			"$KERNEL_DIR"/zImage.stub
		do
			test -e "$f" || continue
			test -d "$BOOT_DIR_ABS" \
				&& DEST="$BOOT_DIR_ABS/$(basename $f)" \
				|| DEST="/boot/$(basename $f)-$KERNEL_VERSION"

			cp -aT "$f" "$DEST"
			test $(command -v restorecon) && restorecon -R "$DEST"
		done

		# hmac file need special treatment
		f="$KERNEL_DIR/.$KERNEL_NAME.hmac"
		if [ -e "$f" ]; then
			test -d "$BOOT_DIR_ABS" \
				&& DEST="$BOOT_DIR_ABS/$(basename $f)" \
				|| DEST="/boot/.$KERNEL_NAME-$KERNEL_VERSION.hmac"

			cp -aT "$f" "$DEST"
			test $(command -v restorecon) && restorecon -R "$DEST"
		fi

		# Set link so zipl finds the kernel
		test -d "$BOOT_DIR_ABS" \
			&& TARGET="$BOOT_DIR_ABS/$KERNEL_NAME" \
			|| TARGET="/boot/$KERNEL_NAME-$KERNEL_VERSION"
		ln -sf "$TARGET" "$ZFCPDUMP_IMAGE"
		;;

	remove)
		# On removal
		# $KERNEL_IMAGE is empty -> $KERNEL_NAME is empty -> rebuild it
		KERNEL_NAME="$(basename $(readlink $ZFCPDUMP_IMAGE))"
		if [ -d "$BOOT_DIR_ABS" ]; then
			INSTALL_DIR="$(dirname $BOOT_DIR_ABS)"
		else
			INSTALL_DIR="/boot/"
			KERNEL_NAME="$(echo $KERNEL_NAME \
				| sed -e "s#\(.*\)-$KERNEL_VERSION#\1#")"
		fi

		for f in $(find "$INSTALL_DIR" -name "*$KERNEL_VERSION*"); do
			rm -rf "$f"
		done

		# Update link to latest remaining zfcpdump kernel.
		if [ $(readlink "$ZFCPDUMP_IMAGE" | grep "$KERNEL_VERSION") ]
		then
			NEXT_IMAGE=$( \
				find "$INSTALL_DIR" -type f \
				| grep '@flavor@' \
				| grep "$KERNEL_NAME" \
				| grep -v "hmac" \
				| sort -V \
				| tail -n1 )

			test $NEXT_IMAGE \
				&& ln -sf "$NEXT_IMAGE" "$ZFCPDUMP_IMAGE" \
				|| rm -f "$ZFCPDUMP_IMAGE"
		fi
		;;
	*)
		;;
esac

# Prevent execution of all other scripts.
# The zfcpdump kernel is stripped down to the bare minimum needed for
# dumping. It is not supposed to be used for any other purpose.
exit 77