[explorer/init] Clean up

This commit is contained in:
Dennis Camera 2020-02-18 01:24:41 +01:00
parent 21c9e3db18
commit d895bb0e87

View file

@ -20,90 +20,151 @@
# along with cdist. If not, see <http://www.gnu.org/licenses/>. # along with cdist. If not, see <http://www.gnu.org/licenses/>.
# #
# #
# Returns the process name of pid 1 ( normaly the init system ) # Returns the name of the init system (PID 1)
# for example at linux this value is "init" or "systemd" in most cases
# #
set -e
# Expected values: # Expected values:
# Linux: # Linux:
# Adélie Linux:
# sysvinit+openrc
# Alpine Linux:
# busybox-init+openrc
# ArchLinux:
# systemd, sysvinit
# CRUX:
# sysvinit
# Debian:
# systemd, upstart, sysvinit, openrc, ???
# Devuan:
# sysvinit, ???
# Gentoo: # Gentoo:
# sysvinit, openrc-init # sysvinit+openrc, openrc-init, systemd
# OpenBMC:
# systemd
# OpenWrt:
# procd, init??
# RedHat (RHEL, CentOS, Fedora, RedHat Linux, ...):
# systemd, upstart, sysvinit
# Slackware:
# sysvinit
# SuSE:
# systemd, sysvinit
# Ubuntu:
# systemd, upstart, sysvinit
#
# GNU: # GNU:
# Debian: # Debian:
# hurd-init, sysvinit # hurd-init, sysvinit
#
# BSD:
# {Free,Open,Net}BSD:
# init
#
# Mac OS X:
# launchd, init
#
# Solaris/Illumos:
# smf, init
# [root@fedora-12 ~]# readlink /proc/1/exe # [root@fedora-12 ~]# readlink /proc/1/exe
# /sbin/init (deleted) # /sbin/init (deleted)
# [root@fedora-12 ~]# ls -l /proc/1/exe # [root@fedora-12 ~]# ls -l /proc/1/exe
# lrwxrwxrwx. 1 root root 0 2020-01-30 23:00 /proc/1/exe -> /sbin/init (deleted) # lrwxrwxrwx. 1 root root 0 2020-01-30 23:00 /proc/1/exe -> /sbin/init (deleted)
# inspired by https://stackoverflow.com/a/33266819 set -e
shreadlink() ( #set -x # DEBUG
CDPATH=
target=$1 fname= targetDir=
# Resolve potential symlinks until the ultimate target is found. validate_busybox_init() {
while : # It is quite common to use SysVinit to stack other init systemd
do # (like OpenRC) on top of it. So we check for that, too.
if ! test -e "$target" if stacked=$(validate_openrc)
then then
printf 'ERROR: %s does not exist.\n' "'$target'" >&2 echo "busybox-init+${stacked}"
return 1
fi
# Change to target dir; necessary for correct resolution of target path.
cd "$(dirname -- "$target")"
fname=$(basename -- "$target") # Extract filename.
[ "$fname" = '/' ] && fname='' # !! curiously, `basename /` returns '/'
[ -L "$fname" ] || break
# Extract [next] target path, which may be defined
# *relative* to the symlink's own directory.
# Note: We parse `ls -l` output to find the symlink target
# which is the only POSIX-compliant, albeit somewhat fragile, way.
# FIXME: Will break if one of the filenames contain ->
target=$(ls -l "$fname" | sed -e 's/^.* -> //')
done
# Get canonical dir. path
targetDir=$(pwd -P)
# Output the ultimate target's canonical path.
# Note that we manually resolve paths ending in /. and /.. to make sure we have a normalized path.
if test "$fname" = '.'
then
printf '%s\n' "${targetDir%/}"
elif test "$fname" = '..'
then
# Caveat: something like /var/.. will resolve to /private (assuming /var@ -> /private/var), i.e. the '..' is applied
# AFTER canonicalization.
printf '%s\n' "$(dirname -- "${targetDir}")"
else else
printf '%s/%s\n' "${targetDir%/}" "$fname" echo busybox-init
fi fi
) }
validate_hurd_init() {
# FIXME: Test me!
test -x /hurd/init || return 1
grep -q 'GNU Hurd' /hurd/init || return 1
echo hurd-init
}
case $(uname -s) in validate_openrc() {
Linux|GNU) test -f /run/openrc/softlevel || return 1
# if test -f /proc/1/comm echo openrc
}
validate_procd() {
grep -q 'procd' /sbin/procd || return 1
echo procd
}
validate_runit() {
test -d /run/runit || return 1
echo runit
}
validate_smf() {
# XXX: Is this the correct way??
test -f /etc/svc/volatile/svc_nonpersist.db || return 1
echo smf
}
validate_systemd() {
# NOTE: sd_booted(3)
test -d /run/systemd/system/ || return 1
# systemctl --version | sed -e '/^systemd/!d;s/^systemd //'
echo systemd
}
validate_sysvinit() {
test -x /sbin/init \
&& grep -q 'INIT_VERSION=sysvinit-[0-9.]*' /sbin/init \
|| return 1
# It is quite common to use SysVinit to stack other init systemd
# (like OpenRC) on top of it. So we check for that, too.
if stacked=$(validate_openrc)
then
echo "sysvinit+${stacked}"
else
echo sysvinit
fi
unset stacked
}
validate_upstart() {
test -x "$(command -v initctl)" || return 1
case $(initctl version)
in
*'(upstart '*')')
# if type -d /etc/init
# then # then
# comm_name=$(cat /proc/1/comm) # # modern (DBus-based?) upstart >= 0.5
# else # :
# BusyBox's versions of ps and pgrep do not support some options # elif type -d /etc/events.d
# depending on which compile-time options have been used. # then
# Both pgrep and ps are tried to get the command name # # ancient upstart
# comm_name=$( # :
# pgrep -P0 -l 2>/dev/null | awk '/^1[ \t]/ { print $2 }'
# || ps -o comm= -p 1 2>/dev/null)
# fi # fi
echo upstart
;;
*)
return 1
;;
esac
}
init_exe=$(shreadlink /proc/1/exe) find_init_procfs() (
# First, check if the required file in procfs exists...
test -h /proc/1/exe || return 1
# Find init executable
init_exe=$(ls -l /proc/1/exe 2>/dev/null)
init_exe=${init_exe#* -> }
if ! test -x "$init_exe" if ! test -x "$init_exe"
then then
@ -122,83 +183,115 @@ case $(uname -s) in
esac esac
fi fi
if test "$init_exe" = '/hurd/init' echo "${init_exe}"
then )
# XXX: Could maybe be removed
echo hurd-init
exit 0
fi
comm_name=$(basename "$init_exe") # BusyBox's versions of ps and pgrep do not support some options
case $comm_name # depending on which compile-time options have been used.
find_init_pgrep() {
pgrep -P0 -fl 2>/dev/null | awk -F '[[:blank:]]' '$1 == 1 { print $2 }'
}
find_init_ps() {
case $(uname -s)
in in
init) Darwin|NetBSD)
: # handled below ps -o ucomm= -p 1 2>/dev/null
;; ;;
systemd) FreeBSD)
# NOTE: sd_booted(3) ps -o command= -p 1 2>/dev/null | cut -d ' ' -f 1
if test -d /run/systemd/system/ ;;
then OpenBSD)
echo systemd ps -o command -p 1 2>/dev/null | tail -n +2 | cut -d ' ' -f 1
exit 0
fi
# otherwise: treat like "init"
;; ;;
*) *)
echo "$comm_name" ps -o comm= -p 1 2>/dev/null
exit 0
;; ;;
esac esac
}
# init: it could be anything... find_init() {
case $("$init_exe" --version 2>/dev/null | head -n 1) case $(uname -s)
in in
SysV*) Linux|GNU|NetBSD)
# This is a little bit more specific than init find_init_procfs || find_init_pgrep || find_init_ps
echo sysvinit
exit 0
;; ;;
*'GNU Hurd'*) FreeBSD)
echo hurd-init find_init_procfs || find_init_ps
;; ;;
*upstart*) OpenBSD)
echo upstart find_init_pgrep || find_init_ps
exit 0
;;
esac
case $("$init_exe" --help 2>/dev/null | head -n 1)
in
BusyBox*)
echo busybox
exit 0
;; ;;
Darwin|FreeBSD|SunOS)
find_init_ps
;;
*)
echo "Don't know how to determine init." >&2
echo 'Please send a patch.' >&2
exit 1
esac esac
}
validate_by_comm_name() {
case $1
in
busybox)
validate_busybox_init
;;
init)
# FIXME: Do some more magic here!
echo init echo init
;; ;;
FreeBSD|OpenBSD) openrc-init)
ps -o comm= -p 1 2>/dev/null || true validate_openrc >/dev/null && echo openrc-init
;; ;;
Darwin) runit)
basename "$(ps -o comm= -p 1 2>/dev/null)" validate_runit
;; ;;
SunOS) systemd)
comm_name=$(ps -o comm= -p 1 2>/dev/null) validate_systemd
if test "$(basename "$comm_name")" != 'init'
then
echo "${comm_name}"
exit 0
fi
# XXX: Is this the correct way??
if test -f /etc/svc/volatile/svc_nonpersist.db
then
echo smf
exit 0
fi
;; ;;
*) *)
# return a empty string as unknown value # Run validate function by comm name if available.
echo "" # Fall back to comm name if either it does not exist or
# returns non-zero.
type "validate_$1" >/dev/null && "validate_$1" || echo $1
esac
}
try_all() {
# init: it could be anything...
# We try some approaches to gather more information about init without
# calling it! On some init systemd this triggers a reinitialisation of
# the system which we don't want (e.g. embedded systems).
validate_sysvinit || \
validate_openrc || \
validate_runit || \
validate_smf || \
validate_upstart || \
validate_hurd_init || \
echo init # fallback
}
init=$(find_init)
if test -x "${init}"
then
case $init
in
/hurd/init)
# FIXME: Create validate function
echo hurd-init
;; ;;
esac */init)
try_all
;;
*)
validate_by_comm_name "$(basename "${init}")"
;;
esac
else
validate_by_comm_name "${init}"
fi