#!/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"
usage()
{
cat <<-_eousage
- Usage: $ME [options]
+ 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.
+
+ Specifying --molly-guard-do-nothing as argument to the command will
+ make $ME echo the command it would execute rather than actually
+ executing it.
- Instead of invoking $EXEC directly, $ME will prompt the user for the
- machine's hostname to guard against accidental shutdowns/reboots, if the
- current shell is a child of an SSH connection (or --pretend-ssh) has been
- given on the command line, if the shell is connected to an interactive
- terminal, and the actual command to execute is does not involve --help or is
- \`shutdown -c'.
+ Options following the double hyphen will be passed unchanged to the
+ scripts.
- Only if the user enters the machine's hostname correctly will $ME take
- action. Specifying --molly-guard-do-nothing as argument to the command will
- make $ME echo the command it would execute rather than actually executing
- it.
+ Please see molly-guard(8) for more information.
The actual command's help output follows:
_eousage
}
-ARGS=
+CMDARGS=
+SCRIPTARGS=
+END_OF_ARGS=0
DO_NOTHING=0
-PRETEND_SSH=0
for arg in "$@"; do
case "$arg" in
(*-molly-guard-do-nothing) DO_NOTHING=1;;
eval $EXEC --help 2>&1
exit 0
;;
- (*-pretend-ssh) PRETEND_SSH=1;;
- *) ARGS="${ARGS:+$ARGS }$arg";;
+ --) END_OF_ARGS=1;;
+ *)
+ if [ $END_OF_ARGS -eq 0 ]; then
+ CMDARGS="${args:+$args }$arg"
+ else
+ SCRIPTARGS="${args:+$args }--arg $arg"
+ fi
+ ;;
esac
done
do_real_cmd()
{
if [ $DO_NOTHING -eq 1 ]; then
- echo "$ME: would run: $EXEC $ARGS"
+ echo "$ME: would run: $EXEC $CMDARGS"
exit 0
else
- eval exec $EXEC "$ARGS"
+ eval exec $EXEC "$CMDARGS"
fi
}
if [ $DO_NOTHING -eq 1 ]; then
- echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing."
-fi
-
-# require an interactive terminal connected to stdin
-test -t 0 || do_real_cmd
-
-# only run if we are being called over SSH, that is if the current terminal
-# was created by sshd.
-PTS=$(readlink /proc/$$/fd/0)
-if ! pgrep -f "^sshd.+${PTS#/dev/}[[:space:]]*$" >/dev/null; then
- if [ $PRETEND_SSH -eq 1 ]; then
- echo "I: this is not an SSH session, but --pretend-ssh was given..."
- else
- do_real_cmd
- fi
-else
- echo "W: $ME: SSH session detected!"
+ echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing." >&2
fi
# pass through certain commands
-case "$CMD $ARGS" in
- (*shutdown\ *-c*)
- echo "I: executing $CMD $ARGS regardless of SSH session."
+case "$CMD $CMDARGS" in
+ (*shutdown\ *-c*)
+ # allow canceling shutdowns
+ echo "I: executing $CMD $CMDARGS regardless of check results." >&2
do_real_cmd
;;
esac
-HOSTNAME="$(hostname --short)"
+MOLLYGUARD_CMD=$CMD; export MOLLYGUARD_CMD
+MOLLYGUARD_DO_NOTHING=$DO_NOTHING; export MOLLYGUARD_DO_NOTHING
+MOLLYGUARD_SETTINGS="/etc/molly-guard/rc"; export MOLLYGUARD_SETTINGS
-sigh()
-{
- echo "Good thing I asked; I won't $CMD $HOSTNAME ..."
- exit 2
-}
-
-trap 'echo;sigh' 1 2 3 9 10 12 15
-
-echo -n "Please type in hostname of the machine to $CMD: "
-read HOSTNAME_USER || :
-
-[ "$HOSTNAME_USER" = "$HOSTNAME" ] || sigh
-
-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." >&2
+ exit $ret
+ fi
+done
do_real_cmd