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|
#!/bin/bash
#
# $Id: testappassive,v 1.1 2005/02/12 23:28:24 andrew Exp $
#
# by Andrew McMillan, Catalyst IT Ltd, (c) 2004 licensed
# for use under the GPL version 2
# Altered by Matthew Grant <grantma@anathoth.gen.nz>, (c) 2004
#
# This script uses "iwlist ${INTERFACE} scan" to see if we can connect to
# a useful local WLAN.
#
###############################################
# NOTE: This script is something of a work in progress. I can't have experience
# with all possible WLAN hardware, so if you need help getting it working with what
# you happen to use, feel free to call upon me.
###############################################
#
# Parameters:
# - first form: [<interface>,]scan
# - second form: <ESSID pattern>
# - third form: [<interface>,]<ESSID pattern>
#
# <interface> Interface to test. If omitted, use INTERFACE variable
# (from detect.conf)
#
# scan Normally we just use the last scan details (if they're less
# than 10 secs old), but sometimes we may want to force a scan.
#
# <ESSID pattern> A pattern that should match the ESSID we are looking for.
#
# Environment variables:
#
# INTERFACE Default interface name to use if not specified
# DEBUGWHEREAMI Turn on debugging output (0 for debug msgs, 1 for execution tracing)
#
# Examples:
# testapscan eth1,scan
# set INTERFACE eth1
# testapscan scan
# testapscan eth1,othercap
# testapscan friendap
# set INTERFACE ath0
# testapscan mywlan
#
STATEDIR=${STATEDIR:-"/var/lib/whereami"}
WHEREAMILOCK=$LOCKDIR/whereami.started
######################################################
# Perform the actual scan, which gets all nearby AP
# details into a file we will use for subsequent calls
######################################################
scan_for_ap()
{
IFSTATE="`ifconfig | egrep \"^${INTERFACE}[\t ]\"`"
if [ "$IFSTATE" = "" ] ; then
ifconfig ${INTERFACE} up
# We seem to need a sleep here to accumulate the
# scan data - for madwifi, at least.
sleep 5
fi
/sbin/iwlist ${INTERFACE} scan >${STATEFILE}
# Be a tidy kiwi, and put the interface back how we found it...
if [ "$IFSTATE" = "" ] ; then
ifconfig ${INTERFACE} down
fi
}
######################################################
# Utility to do pattern match, with awkward quoting
######################################################
ap_pattern_match()
{
egrep "ESSID:\"$1\"" "${STATEFILE}"
}
######################################################
# Test if there is an AP in our scan that matches
######################################################
test_which_ap()
{
ap_pattern_match "$1" >/dev/null
}
# Turn on execution tracing, for debugging...
[ -n "$DEBUGWHEREAMI" ] && set -o xtrace
PATTERN=""
ACTION="test"
INTERFACE=${INTERFACE:-eth0}
case $1 in
*,scan)
# First form
INTERFACE=${1/,scan}
ACTION="scan"
;;
scan)
# First form
INTERFACE=${INTERFACE:-eth0}
ACTION="scan"
;;
*,*)
# Third form
INTERFACE=${1/,*}
PATTERN=${1/*,}
;;
*)
# Second form
PATTERN="$1"
;;
esac
STATEFILE=$STATEDIR/iwlist.$INTERFACE
mkdir -p $STATEDIR
STATUS=1
if [ "$ACTION" = "scan" ] ; then
scan_for_ap
STATUS=$?
fi
if [ "$PATTERN" != "" ];then
test_which_ap "$PATTERN"
STATUS=$?
fi
exit $STATUS
|
