From ecdbd1cb447dca36108ca5fe0c4c6d366a09ae70 Mon Sep 17 00:00:00 2001 From: Andrew Ruthven Date: Sat, 19 Apr 2008 13:50:49 +1200 Subject: [PATCH 1/1] Use run-parts to run a selection of different guards. --- checks.d/molly-guard | 61 ++++++++++++++++++++++++++++++++++++++++ shutdown | 67 ++++++++++++++------------------------------ 2 files changed, 82 insertions(+), 46 deletions(-) create mode 100755 checks.d/molly-guard diff --git a/checks.d/molly-guard b/checks.d/molly-guard new file mode 100755 index 0000000..a9a2e90 --- /dev/null +++ b/checks.d/molly-guard @@ -0,0 +1,61 @@ +#!/bin/sh +# +# molly-guard -- wrapper script to prevent erroneous shutdowns via SSH +# +# Copyright © martin f. krafft +# Released under the terms of the Artistic Licence 2.0 +# +set -eu + +ME=molly-guard + +PRETEND_SSH=0 +CMD=$1 +shift +for arg in "$@"; do + case "$arg" in + (*-help) + usage 2>&1 + eval $EXEC --help 2>&1 + exit 1 + ;; + (*-pretend-ssh) PRETEND_SSH=1;; + esac +done + +# require an interactive terminal connected to stdin +test -t 0 || exit 0 + +# only run if we are being called over SSH, that is if the current terminal +# was created by sshd. +PTS=$(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 + exit 0 + fi +else + echo "W: $ME: SSH session detected!" +fi + + +HOSTNAME="$(hostname --short)" + +sigh() +{ + echo "Good thing I asked; I won't $CMD $HOSTNAME ..." + exit 1 +} + +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 + +exit 0 diff --git a/shutdown b/shutdown index 0c52d92..c68b572 100755 --- a/shutdown +++ b/shutdown @@ -37,15 +37,18 @@ usage() 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'. + + 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. @@ -56,7 +59,7 @@ usage() ARGS= DO_NOTHING=0 -PRETEND_SSH=0 +CHECK_ARGS= for arg in "$@"; do case "$arg" in (*-molly-guard-do-nothing) DO_NOTHING=1;; @@ -65,7 +68,7 @@ for arg in "$@"; do 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 @@ -84,46 +87,18 @@ 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 \ - && [ -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 $CHECK_ARGS /usr/share/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 -- 2.39.5