jobcore/runit-rc/binfmt.sh
2024-09-07 18:30:17 +03:00

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#!/bin/sh
# This is a reimplementation of the systemd binfmt.d code to register
# misc binary formats with the kernel.
#
# See the binfmt.d manpage as well:
# http://0pointer.de/public/systemd-man/binfmt.d.html
# This script should match the manpage as of 2015/03/31
# Copyright (c) 2015 The OpenRC Authors.
# See the Authors file at the top-level directory of this distribution and
# https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
#
# This file is part of OpenRC. It is subject to the license terms in
# the LICENSE file found in the top-level directory of this
# distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
# This file may not be copied, modified, propagated, or distributed
# except according to the terms contained in the LICENSE file.
apply_file() {
[ $# -lt 1 ] && return 0
FILE="$1"
LINENUM=0
### FILE FORMAT ###
# See https://www.kernel.org/doc/Documentation/binfmt_misc.txt
while read -r line; do
LINENUM=$(( LINENUM+1 ))
case $line in
\#*) continue ;;
\;*) continue ;;
'') continue ;;
esac
reg=${line#*:}
[ -e "$binfmt_fs/${reg%%:*}" ] && printf "%d" -1 > "$binfmt_fs/${reg%%:*}"
printf "%s" "${line}" > "$binfmt_fs"/register
rc=$?
if [ $rc -ne 0 ]; then
printf "binfmt: invalid entry on line %d of \`%s'\n" "$LINENUM" "$FILE" >&2
error=1
fi
done < "$FILE"
return "$rc"
}
readonly binfmt_fs="/proc/sys/fs/binfmt_misc"
# Mount binfmt if it isn't mounted alraedy
mountpoint -q $binfmt_fs || mount -t binfmt_misc binfmt $binfmt_fs
[ -e "$binfmt_fs"/register ] || exit 0
error=0
if [ $# -gt 0 ]; then
while [ $# -gt 0 ]; do
apply_file "$1"
shift
done
else
# The hardcoding of these paths is intentional; we are following the
# systemd spec.
binfmt_dirs='/usr/lib/binfmt.d /run/binfmt.d /etc/binfmt.d'
binfmt_basenames=''
binfmt_d=''
# Build a list of sorted unique basenames
# directories declared later in the binfmt_d list will override earlier
# directories, on a per file basename basis.
# `/run/binfmt.d/foo.conf' supersedes `/usr/lib/binfmt.d/foo.conf'.
# `/run/binfmt.d/foo.conf' will always be read after `/etc/binfmt.d/bar.conf'
for d in ${binfmt_dirs}; do
if [ -d "$d" ]; then
for f in "${d}"/*.conf; do
case "${f##*/}" in
systemd.conf|systemd-*.conf) continue;;
esac
[ -e "$f" ] && binfmt_basenames="${binfmt_basenames} ${f##*/}"
done
fi
done
binfmt_basenames="$(printf "%s\n" "${binfmt_basenames}" | sort -u )"
for b in $binfmt_basenames; do
real_f=''
for d in $binfmt_dirs; do
f=${d}/${b}
[ -e "${f}" ] && real_f=$f
done
[ -e "${real_f}" ] && binfmt_d="${binfmt_d} ${real_f}"
done
# loop through the gathered fragments, sorted globally by filename.
# `/run/binfmt.d/foo.conf' will always be read after `/etc/binfmt.d/bar.conf'
for FILE in $binfmt_d; do
apply_file "$FILE"
done
fi
exit $error
# vim: set ts=2 sw=2 sts=2 noet ft=sh: