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script to Auto connect to Open wirelss 802.11 AP's

wifiweasel

wifiweasel v1 once run this script takes control of the wireless interface detects and connects to strongest open wifi AP in the vicinity and checks connectivity every X seconds if connection fails the whole proccess repeats itself, requires timeout script below

• needs to be tested with multiple AP's might have a iwconfig essid glitch

 
#!/bin/sh
   #####################
###########################
#/var/wifi/hacker/kd8ikt###
# OMG i'm programming now!#
###########################
###we.trekbeyond.org#######
  #####################
        #KISS#

# CONFIG
#######interface################
IFACE=eth0 
#Dhcp_timeout
DHCP=4
#check connectivity every X sec
X=30
#
# /CONFIG
################################
#### Scan Funk ####
Func_iwlist_open () {
iwlist $IFACE scanning | awk -F '[ :=]+' '/(ESS|Freq|Qual)/{ printf $3" " } /Encr/{ print $4 }' \
    | sort -k4 -k3nr |grep off \
|awk '{print $1}' > /tmp/weasel
sed /\"/s/\"//g /tmp/weasel > /tmp/ESSID
}
#### iface up Funk ######## 
Func_ifconfig_up () {
iwconfig $IFACE essid `cat /tmp/ESSID` 
}
#### iface down Funk #####
Func_ifconfig_down () {
killall udhcpc 
ifconfig $IFACE down	
}
#### Conn Funk #####
Func_chk_net ()	{
ifconfig usb0 down
export gate=`ip route show to 0/0 |awk '{print $3}'`| ping -w 2 -c2  $gate > /dev/null
if [ $=0 ];then ERROR=0; echo Online!  go download some pr0n ;sleep $X; Func_chk_net ; 
fi  #W00T  
if [ $=1 ] ; then ERROR=1 ;echo FAIL!\ 
... Searching ; Func_Main ;
fi 
 }
#### Main Funk #########
Func_MAIN () { while [ ERROR=1 ] ; do
Func_ifconfig_down ;
Func_iwlist_open Func_ifconfig_up ;
timeout $DHCP udhcpc $IFACE > /dev/null ;
Func_chk_net ;
Func_MAIN ;
done; 
} 
#### MAIN #### 
Func_ifconfig_down ;
Func_iwlist_open Func_ifconfig_up  ; 
udhcpc $IFACE ; 
Func_chk_net ; 
Func_MAIN ;
echo This is the end my only friend the end
Done; #actually i dont think it ever ends
#####################EOF##################

timeout

added timout script to keep udhcpc from hanging everything cause we all know dhcp doesnt take 60 sec if its not in by 2-3 sec guess what? you aint getting an ip (range issues/mac filtering etc)

INSTALL /usr/bin/timeout

#Newsgroups: comp.unix.admin,comp.unix.solaris,comp.unix.shell
#From: gwc@root.co.uk (Geoff Clare)
#Subject: Re: timeout -t <sec> <unix command> (Re: How to give rsh a shorter timeout?)
#Message-ID: <EoBxrs.223@root.co.uk>
#Date: Fri, 13 Feb 1998 18:23:52 GMT

#
# Conversion to bash v2 syntax done by Chet Ramey <chet@po.cwru.edu
# UNTESTED
#

prog=${0##*/}
usage="usage: $prog [-signal] [timeout] [:interval] [+delay] [--] <command>"

SIG=-TERM       # default signal sent to the process when the timer expires
timeout=60      # default timeout
interval=15     # default interval between checks if the process is still alive
delay=2         # default delay between posting the given signal and
                # destroying the process (kill -KILL)

while :
do
        case $1 in
        --)     shift; break ;;
        -*)     SIG=$1 ;;
        [0-9]*) timeout=$1 ;;
        :*)     EXPR='..\(.*\)' ; interval=`expr x"$1" : "$EXPR"` ;;
        +*)     EXPR='..\(.*\)' ; delay=`expr x"$1" : "$EXPR"` ;;
        *)      break ;;
        esac
        shift
done

case $# in
0)      echo "$prog: $usage" >&2 ; exit 2 ;;
esac

(
        for t in $timeout $delay
        do
                while (( $t > $interval ))
                do
                        sleep $interval
                        kill -0 $$ || exit
                        t=$(( $t - $interval ))
                done
                sleep $t
                kill $SIG $$ && kill -0 $$ || exit
                SIG=-KILL
        done
) 2> /dev/null &

exec "$@"

sandbox

iwscan perl

#!/usr/bin/perl
# Tim Osburn - tim@osburn.com
#
# install perl

$iwlist = "/sbin/iwlist eth0 scanning";

open scan, "$iwlist |";
while (<scan>) {
  if (/^\s+Cell (\S+) - Address: (\S+)/) {
    $CELL=$1;
    $ADDRESS=$2;
    # print "$1 $2";
    $INLOOP=1;
    }
  if (/^\s+ESSID:(\S+)/) {
    $ESSID=$1;
    print " $1";
    }
  if (/^\s+Frequency:\S+ \S+ \(Channel (\S+)\)/) {
    $CHAN=$1;
    print " $1";
    }
  if (/^\s+Quality=\S+\s+Signal level=(\S+).*/) {
    $SIGNAL=$1;
    print " $1";
    }
  if (/^\s+Encryption key:(\S+)/) {
    $ENCRYPTION=$1;
    print " $1\n";
    }
  }
close scan;

produces output in the form of "essid" channel signal_strength encryption_status

"ESSID_NAME1" 1 -82 on
"ESSID_NAME2" 1 -49 off

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