* Fix the regular expression to find the sshd parent process.

[code/molly-guard.git] / shutdown

diff --git a/shutdown b/shutdown
index 65fd374b2dfd87e8050394085ae2f07941bb9606..0135f1aa435ba2fb38e77529b767983e44b0ad21 100755 (executable)
--- a/shutdown
+++ b/shutdown
@@ -15,10 +15,11 @@ CMD="${0##*/}"
 EXEC="/sbin/$CMD"
 
 case "$CMD" in
-  halt|reboot|shutdown)
+  halt|reboot|shutdown|poweroff)
     if [ ! -f $EXEC ]; then
       echo "E: $ME: not a regular file: $EXEC" >&2
       exit 4
+    fi
     if [ ! -x $EXEC ]; then
       echo "E: $ME: not an executable: $EXEC" >&2
       exit 3
@@ -33,25 +34,48 @@ ARGS="$@"
 
 do_real_cmd()
 {
-  exec $EXEC "$ARGS"
+  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
 }
 
-# require $SSH_CONNECTION to be set, indicates an SSH session
-[ -n "${SSH_CONNECTION:-}" ] || do_real_cmd
 # 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)
+pgrep -f "^sshd.+${PTS#/dev/}[[:space:]]*$" >/dev/null || do_real_cmd
+
 # pass through help commands
 case "$CMD $ARGS" in
-  'shutdown*-c'|'*-h') do_real_cmd;;
+  (shutdown\ *-c*) do_real_cmd;;
+  (shutdown\ *-h*) do_real_cmd;;
+  (*--help*) do_real_cmd;;
   *) :;;
 esac
 
-echo -n "$ME: SSH session detected, type in hostname of the machine to $CMD: "
-read HOSTNAME_USER
-
 HOSTNAME="$(hostname)"
 
-if [ "$HOSTNAME_USER" != "$HOSTNAME" ]; then
+sigh()
+{
   echo "Good thing I asked; I won't $CMD $HOSTNAME ..."
   exit 2
-fi
+}
+
+trap 'echo;sigh' 1 2 3 9 10 12 15
+
+echo "$ME: SSH session detected!"
+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