#!/bin/sh
# Copyright (c) 2013 Bob Beck <beck@obtuse.com>  All rights reserved.
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

# Script to monitor a wireless interface and try different nwids, along
# with using an activation script when we bind to a network. useful
# on OpenBSD 5.3 or later.
#

# To use, first decide where you will put the config files, and set
# the variable below:
CONFDIR=/usr/local/etc

# now, assuming your interface name is "iwn0" - in the above directory
# you want a file "nwids.iwn0" containing arguments to ifconfig to
# change the nwid of your interface. they will always be tried in the
# order of the file, so mine has my home network, and a bunch of guest
# nets in it, with my home at the top. so my "nwids.iwn0" file looks
# like:

#---------------
#nwid bob
#nwid fatherland wpakey "obama"
#nwid AGLC_WLAN
#nwid Guest@UofA
#------------------

# You then need to make sure you have dhclient running on the
# interface and run this script (wifinwid) with the interface as the
# argument i.e.

# wifinwid iwn0 &

# You may optionally then have an "activate.nwid" file in the same
# directory which if present and executable is run when the network is
# brought up. this is very useful for networks with stupid captive
# proxy "click here to agree" stuff in them. I capture the "click to
# agree" answer and send it to the designated server for the captive
# proxy thing.  For example, I have an "activate.Guest@UofA" script
# that looks like this:

#-----------------
##/bin/sh
#cat /usr/local/etc/uaguest.raw | nc 1.1.1.1 80
#------------------

# Where "uaguest.raw" is the POST request to agree and 1.1.1.1 is the
# IP used by this captive proxy network.. figuring out what to send is
# left as an exercise to the reader.

# You may need to adjust this value below if your wireless interface
# is particularly slow to bind. your DHCP server slow to respond,
# etc. 5-6 seconds works for me (tm). if you find it misses your
# networks make thie value bigger.
DELAY=6

## Don't fiddle below here there be dragons.
progname=`basename $0`
while :; do
(ifconfig $1 | grep 'status: active' > /dev/null)
if [ $? -ne 0 ]; then
    logger -p daemon.debug -t $progname "interface $1 appears inactive"
    cat $CONFDIR/nwids.$1 | while read LINE
    do
      logger -p daemon.debug -t $progname "trying ifconfig $1 $LINE"
      ifconfig $1 $LINE
      sleep $DELAY
      (ifconfig $1 | grep 'status: active' > /dev/null)
      if [ $? -eq 0 ]; then
	  nwid=`ifconfig $1 | grep nwid | sed 's/.*nwid //' | sed 's/ chan.*$//'`
	  logger -p daemon.info -t $progname "attached to network $nwid on interface $1"
	  sleep $DELAY
	  if [ -x $CONFDIR/activate.$nwid ]; then
	      $CONFDIR/activate.$nwid
	   fi
	  break
       fi
    done
else
    sleep 2
fi
done