#! /bin/bash -eu

# Maintain kernel-version-specific symlinks in /lib/firmware based on

# configuration present in /usr/share/microcode_ctl/ucode_with_caveats.

#

# SPDX-License-Identifier: CC0-1.0

export LC_ALL=C

usage()

{

	echo "Usage: update_ucode [--action {add|remove|refresh|list}]" \

	     "[--kernel KERNELVER]* [--verbose] [--dry-run]" \

	     "[--cleanup intel_ucode caveats_ucode]" \

	     "[--skip-common] [--skip-kernel-specific]" >&2

}

debug() { [ 0 = "$verbose" ] || echo "$*" >&2; }

# Calls find only if the first argument exists and is a directory.

# Avoids spurious "find: '...' No such file or directory" for the directories

# that may not exist.

find_d() { [ \! -d "$1" ] || find "$@"; }

MC_DIR=/usr/share/microcode_ctl

INTEL_UCODE_DIR=intel-ucode

DATA_DIR=/usr/share/microcode_ctl/ucode_with_caveats

FW_DIR=/lib/firmware

check_caveats=/usr/libexec/microcode_ctl/check_caveats

action=refresh

kernel=

verbose=0

verbose_opt=

dry_run=0

remove_cleanup=0

cleanup_intel=

cleanup_caveats=

skip_common=0

skip_caveats=0

while [ 1 -le "$#" ]; do

	case "$1" in

	-C|--skip-common)

		skip_common=1

		;;

	-K|--skip-kernel-specific)

		skip_caveats=1

		;;

	-a|--action)

		shift

		action="$1"

		;;

	-k|--kernel)

		shift

		kernel="$kernel $1"

		;;

	-v|--verbose)

		verbose=1

		verbose_opt="-v"

		;;

	-n|--dry-run)

		dry_run=1

		;;

	-c|--cleanup)

		remove_cleanup=1

		shift

		cleanup_intel="$1"

		shift

		cleanup_caveats="$1"

		;;

	*)

		echo "Unknown argument \"$1\"" >&2

		usage

		exit 1

	esac

	shift

done

cmd=

[ 0 -eq "$dry_run" ] || cmd=echo

case "$action" in

add|remove|refresh|list)

	# Scan all directories in FW_DIR and all existing kernels

	if [ -z "$kernel" ]; then

		debug "No kernel versions provided, scanning..."

		kvers=$(find_d /lib/modules/ -name '[2-9].*' -print)

		for k_dir in $kvers; do

			k="${k_dir#/lib/modules/}"

			[ ! -e "/boot/symvers-$k.gz" ] || {

				debug "  Adding $k (from /lib/modules)"

				kernel="$kernel $k"

			}

		done

		kvers=$(find_d /lib/firmware/ -name '[2-9].*' -print)

		for k_dir in $kvers; do

			k="${k_dir#/lib/firmware/}"

			[ ! -d "$k_dir" ] || {

				debug "  Adding $k (from /lib/firmware)"

				kernel="$kernel $k"

			}

		done

		kernel=$(printf "%s" "$kernel" | xargs -n 1 | sort -u)

	fi

	;;

*)

	echo "Unknown action \"$action\"" >&2

	usage

	exit 1

	;;

esac

# Generic part: managing intel ucode

debug "Running action \"$action\" on common Intel microcode directory"

while :; do

	[ 0 -eq "$skip_common" ] || break

	[ ! -e "/etc/microcode_ctl/intel-ucode-disallow" ] || {

		debug "  Skipping \"$i\":" \

		      "\"/etc/microcode_ctl/intel-ucode-disallow\"" \

		      "present"

		break

	}

	[ ! -e "$FW_DIR/intel-ucode-disallow" ] || {

		debug "  Found \"$FW_DIR/intel-ucode-disallow\"," \

		      "skipping"

		break

	}

	# Removing old files

	case "$action" in

	refresh|remove|list)

		debug "  Removing old files from ${FW_DIR}/${INTEL_UCODE_DIR}"

		if [ 0 = "$remove_cleanup" ]; then

			find_d "${MC_DIR}/${INTEL_UCODE_DIR}" \

				-maxdepth 1 -mindepth 1 \

				-type f -printf '%f\n'

		else

			cat "$cleanup_intel"

		fi | while read -r fname; do

			name="${FW_DIR}/${INTEL_UCODE_DIR}/${fname}"

			# Needed in case we downgrade to a version where

			# no symlinks in /lib/firmware were used

			if [ 1 = "$remove_cleanup" ]; then

				[ -L "$name" ] || continue

			fi

			[ "xlist" != "x$action" ] || {

				echo "$name"

				continue

			}

			$cmd rm -f $verbose_opt "$name"

		done

		[ "xlist" = "x$action" ] || {

			# Removing possible dangling symlinks

			find_d "${FW_DIR}/${INTEL_UCODE_DIR}" \

				-maxdepth 1 -mindepth 1 \

				-type l -printf '%p\n' \

			| while read -r fname; do

				[ -e "$fname" ] || {

					debug "    Removing danging symlink \"$fname\""

					$cmd rm -f $verbose_opt "$fname"

				}

			done

			$cmd rmdir -p $verbose_opt \

				"${FW_DIR}/${INTEL_UCODE_DIR}" 2>/dev/null \

				|| true

		}

		;;

	esac

	# Adding new ones

	case "$action" in

	add|refresh)

		debug "  Creating symlinks in ${FW_DIR}/${INTEL_UCODE_DIR}"

		$cmd mkdir -p $verbose_opt "${FW_DIR}/${INTEL_UCODE_DIR}"

		$cmd find "${MC_DIR}/${INTEL_UCODE_DIR}" -maxdepth 1 -mindepth 1 \

			-type f -exec bash -c 'ln -fs '"$verbose_opt"' '\''{}'\'' \

				"'"${FW_DIR}/${INTEL_UCODE_DIR}/"'$(basename '\''{}'\'')"' \;

		;;

	esac

	break

done

debug "Running action \"$action\" on kernels $kernel"

if [ 0 = "$remove_cleanup" ]; then

	ls "$DATA_DIR"

else

	cat "$cleanup_caveats"

fi | while read -r i; do

	[ 0 -eq "$skip_caveats" ] || break

	debug "Processing data directory \"$i\"..."

	for k in $(echo "$kernel"); do

		debug "    Processing kernel version \"$k\""

		{

			out=$($check_caveats -k "$k" -c "$i" $verbose_opt)

			ret="$?"

		} || :

		paths=$(printf "%s" "$out" | sed -n 's/^paths //p')

		ignore=$(printf "%s" "$out" | sed -n 's/^skip_cfgs //p')

		[ -z "$ignore" ] || {

			debug "      Configuration is ignored, skipping"

			continue

		}

		case "$action" in

		remove|refresh|list)

			[ "xlist" = "x$action" ] || \

				debug "    Removing \"$paths\" (part of $action)..."

			for p in $(printf "%s" "$paths"); do

				find_d "$DATA_DIR/$i" -path "$DATA_DIR/$i/$p" \

					-printf "%P\n"

			done | while read -r path; do

				[ -e "$FW_DIR/$k/readme-$i" ] || {

					debug "      \"$FW_DIR/$k/readme-$i\"" \

					      "is not found, skipping" \

					      "\"$paths\" removal"

					break

				}

				if [ "xlist" = "x$action" ]; then

					echo "$FW_DIR/$k/$path"

				else

					debug "      Removing \"$FW_DIR/$k/$path\""

					$cmd rm -f $verbose_opt "$FW_DIR/$k/$path"

					$cmd rmdir -p $verbose_opt \

						"$FW_DIR/$k/$(dirname $path)" 2>/dev/null \

						|| true

				fi

			done

			if [ -e "$FW_DIR/$k/readme-$i" ]; then

				if [ "xlist" = "x$action" ]; then

					echo "$FW_DIR/$k/readme-$i"

				else

					$cmd rm -f $verbose_opt \

						"$FW_DIR/$k/readme-$i"

					$cmd rmdir -p $verbose_opt \

						"$FW_DIR/$k" 2>/dev/null || true

				fi

			fi

			;;

		esac

		[ 0 -eq "$ret" ] || {

			debug "    Checking for caveats failed" \

			      "(kernel version \"$k\"), skipping"

			continue

		}

		[ -n "$paths" ] || {

			debug "    List of paths to add is empty, skipping"

			continue

		}

		case "$action" in

		add|refresh)

			debug "    Adding $paths (part of $action)..."

			[ -e "/boot/symvers-$k.gz" ] || {

				debug "      \"/boot/symvers-$k.gz\"" \

				      "does not exist, skipping"

				continue

			}

			for p in $(printf "%s" "$paths"); do

				find_d "$DATA_DIR/$i" -path "$DATA_DIR/$i/$p" \

					-printf "%P\n"

			done | while read -r path; do

				[ ! -e "$FW_DIR/$k/$path" ] || {

					debug "      $FW_DIR/$k/$path already" \

					      "exists, skipping"

					continue

				}

				debug "      Adding \"$FW_DIR/$k/$path\""

				$cmd mkdir -p $verbose_opt \

					"$(dirname "$FW_DIR/$k/$path")"

				$cmd ln -fs $verbose_opt "$DATA_DIR/$i/$path" \

					"$FW_DIR/$k/$path"

			done

			if [ -e "$FW_DIR/$k/readme-$i" ]; then

				debug "        $FW_DIR/$k/readme-$i already" \

				      "exists, skipping creation"

			else

				$cmd cp $verbose_opt "$DATA_DIR/$i/readme" \

					"$FW_DIR/$k/readme-$i"

			fi

			;;

		remove)

		esac

	done

done

# Removing possible dangling symlinks in kernel-specific directories

debug "Checking for dangling symlinks..."

for k in $(echo "$kernel"); do

	debug "  Processing kernel version \"$k\""

	find_d "${FW_DIR}/${k}" \

		-mindepth 1 -type l -printf '%p\n' \

	| while read -r fname; do

		[ -e "$fname" ] || {

			debug "    Removing danging symlink \"$fname\""

			$cmd rm -f $verbose_opt "$fname"

		}

	done

done