#! /bin/sh

### BEGIN INIT INFO
# Provides:          tunnel
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Outbound SSH tunnels
# Description:       This script starts or stops the outbound SSH tunnels
#			maintained by the `tunnel' user.
### END INIT INFO

# Author: Mark Wooding <mdw@distorted.org.uk>

## Initial configuration.
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="outbound SSH tunnels"
TUNUSER=tunnel
RUN=/var/run/$TUNUSER
if [ -f /etc/default/tunnel ]; then . /etc/default/tunnel; fi
: ${TUNHOME=$(getent passwd "$TUNUSER" | cut -d: -f6)}
: ${TUNGROUP=$(id -g "$TUNUSER")}
if [ ! -x "$TUNHOME/bin/outbound" ]; then exit 0; fi
: ${tunnels=$(sed -n \
  '/^Host[[:space:]]\+\([^[:space:]*]\|[^[:space:]].*[^[:space:]]\)[[:space:]]*$/s//\1/p' \
  "$TUNHOME/.ssh/config")}

## Scan the command-line.
case "$#" in
  0) op=none ;;
  1) op=$1; shift; set -- $tunnels ;;
  *) op=$1; shift ;;
esac

## Make sure that the runtime state directory exists.  If not, create it with
## sensible permissions.  Don't override permissions if it already exists,
## because presumably the administrator has fiddled them deliberately.
if [ ! -d "$RUN" ]; then
  mkdir -m755 "$RUN"
  chown "$TUNUSER:$TUNGROUP" "$RUN"
fi
cd "$RUN"

## Utility to run the per-host script.
run_outbound () { sudo -u"$TUNUSER" "$TUNHOME/bin/outbound" "$@"; }

## Utilities for doing things to individual hosts.
start () { run_outbound start "$1"; }
stop () { run_outbound stop "$1"; }
restart () { stop "$1"; start "$1"; }

## Higher-order iterator to process a list of hosts.
foreach () {
  whatting=$1 what=$2; shift 2
  echo -n "$whatting $DESC:"
  for i in "$@"; do
    $what "$i"
    echo -n " $i"
  done
  echo "."
}

## Main dispatch.
case $op in
  start) foreach "Starting" start "$@" ;;
  stop) foreach "Stopping" stop "$@" ;;
  restart | force-reload) foreach "Restarting" restart "$@" ;;
  status)
    for i in "$@"; do
      echo -n "$i: "
      run_outbound status "$i"
    done
    ;;
  *)
    echo >&2 "usage: $0 {start|stop|restart|status} [HOST ...]"
    exit 1
    ;;
esac