# 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
+CHECKSDIR=/etc/molly-guard/checks.d
CMD="${0##*/}"
EXEC="/sbin/$CMD"
Usage: $ME [options]
(shielding $EXEC)
- 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'.
-
- 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
+ Instead of invoking $EXEC directly, $ME will run a number of checks
+ to guard against accidental shutdowns/reboots.
+
+ Some of the checks available are:
+ - Prompt the user for the machine's 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'.
+
+ $ME will always interpose the prompt if the environment variable
+ ALWAYS_MOLLY is set to '1'. This variable may be set in the file
+ /etc/default/${ME} .
+
+ - Print out a warning message with information about this host
+ before the action takes place. You can use:
+ /etc/molly-guard.<Action>.message
+ To print out a message specific to the command you're trying to
+ use. Or:
+ /etc/molly-guard.message
+ For a general warning message.
+
+ Only if the user satisfies all the checks will $ME take action.
+ Specifying --molly-guard-do-nothing as argument to the command will
make $ME echo the command it would execute rather than actually executing
it.
ARGS=
DO_NOTHING=0
-PRETEND_SSH=0
+CHECK_ARGS=
for arg in "$@"; do
case "$arg" in
(*-molly-guard-do-nothing) DO_NOTHING=1;;
eval $EXEC --help 2>&1
exit 0
;;
- (*-pretend-ssh) PRETEND_SSH=1;;
+ (*-pretend-ssh) CHECK_ARGS="${CHECK_ARGS:+$CHECK_ARGS }--arg --pretend-ssh";;
*) ARGS="${ARGS:+$ARGS }$arg";;
esac
done
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 \
- && [ -z "$SSH_CONNECTION" ]; 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: $ME: SSH session detected!"
-fi
-
# pass through certain commands
case "$CMD $ARGS" in
(*shutdown\ *-c*)
- echo "I: executing $CMD $ARGS regardless of SSH session."
+ echo "I: executing $CMD $ARGS regardless of check results."
do_real_cmd
;;
esac
-HOSTNAME="$(hostname --short)"
+run-parts --exit-on-error --arg $CMD $CHECK_ARGS /etc/molly-guard/checks.d
-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
-
-do_real_cmd
+# run-parts won't return to us if there are failures, but I'm paranoid.
+if [ $? == 0 ]; then
+ do_real_cmd
+ exit
+fi