#!/bin/sh
#
-# shutdown -- wrapper script to prevent erroneous shutdowns via SSH
+# shutdown -- wrapper script to guard against accidental shutdowns
#
# Copyright © martin f. krafft <madduck@madduck.net>
# Released under the terms of the Artistic Licence 2.0
#
-# $Id: shutdown 299 2006-10-16 14:40:47Z madduck $
-#
set -eu
ME=molly-guard
+VERSION=0.4
+SCRIPTSDIR=/etc/molly-guard/run.d
+SCRIPTSDIR="${0%/*}/run.d"
CMD="${0##*/}"
EXEC="/sbin/$CMD"
exit 1
;;
esac
-ARGS="$@"
-do_real_cmd()
+usage()
{
- case "$ARGS" in
- (*--molly-guard-do-nothing*)
- ARGS0="${ARGS%%--molly-guard-do-nothing*}"
- ARGS1="${ARGS##*--molly-guard-do-nothing}"
- echo "$ME: would run: $EXEC ${ARGS0# } ${ARGS1# }"
- exit 0;;
- *) eval exec $EXEC "$ARGS";;
- esac
-}
+ cat <<-_eousage
+ Usage: $ME [options] [-- script options]
+ (shielding $EXEC)
+
+ molly-guard's primary goal is to guard against accidental
+ shutdowns/reboots. $ME will run all scripts in $SCRIPTSDIR and only
+ invokes $EXEC if all scripts exited successfully.
-# require an interactive terminal connected to stdin
-test -t 0 || do_real_cmd
+ Specifying --molly-guard-do-nothing as argument to the command will
+ make $ME echo the command it would execute rather than actually
+ executing it.
-# only run if we are being called over SSH, that is if the current terminal
-# was created by sshd.
-PTS=$(readlink /proc/$$/fd/0)
-pgrep -f "^sshd.+${PTS#/dev/}[[:space:]]*$" >/dev/null || do_real_cmd
+ Options following the double hyphen will be passed unchanged to the
+ scripts.
-# pass through help commands
-case "$CMD $ARGS" in
- (shutdown\ *-c*) do_real_cmd;;
- (shutdown\ *-h*) do_real_cmd;;
- (*--help*) do_real_cmd;;
- *) :;;
-esac
+ Please see molly-guard(8) for more information.
+
+ The actual command's help output follows:
-HOSTNAME="$(hostname)"
+ _eousage
+}
+
+CMDARGS=
+SCRIPTARGS=
+END_OF_ARGS=0
+DO_NOTHING=0
+for arg in "$@"; do
+ case "$arg" in
+ (*-molly-guard-do-nothing) DO_NOTHING=1;;
+ (*-help)
+ usage 2>&1
+ eval $EXEC --help 2>&1
+ exit 0
+ ;;
+ --) END_OF_ARGS=1;;
+ *)
+ if [ $END_OF_ARGS -eq 0 ]; then
+ CMDARGS="${args:+$args }$arg"
+ else
+ SCRIPTARGS="${args:+$args }--arg $arg"
+ fi
+ ;;
+ esac
+done
-sigh()
+do_real_cmd()
{
- echo "Good thing I asked; I won't $CMD $HOSTNAME ..."
- exit 2
+ if [ $DO_NOTHING -eq 1 ]; then
+ echo "$ME: would run: $EXEC $CMDARGS"
+ exit 0
+ else
+ eval exec $EXEC "$CMDARGS"
+ fi
}
-trap 'echo;sigh' 1 2 3 9 10 12 15
+if [ $DO_NOTHING -eq 1 ]; then
+ echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing."
+fi
-echo "$ME: SSH session detected!"
-echo -n "Please type in hostname of the machine to $CMD: "
-read HOSTNAME_USER || :
+# pass through certain commands
+case "$CMD $CMDARGS" in
+ (*shutdown\ *-c*)
+ # allow canceling shutdowns
+ echo "I: executing $CMD $CMDARGS regardless of check results."
+ do_real_cmd
+ ;;
+esac
-[ "$HOSTNAME_USER" = "$HOSTNAME" ] || sigh
+MOLLYGUARD_CMD=$CMD; export MOLLYGUARD_CMD
+MOLLYGUARD_DO_NOTHING=$DO_NOTHING; export MOLLYGUARD_DO_NOTHING
+MOLLYGUARD_SETTINGS="/etc/default/$ME"; export MOLLYGUARD_SETTINGS
-trap - 1 2 3 9 10 12 15
+for script in $(run-parts --test $SCRIPTSDIR); do
+ ret=0
+ eval $script $SCRIPTARGS || ret=$?
+ if [ $ret -ne 0 ]; then
+ echo "W: aborting $CMD due to ${script##*/} exiting with code $ret."
+ exit $ret
+ fi
+done
do_real_cmd