sitesurvey

#!/bin/sh

# Copyright (c) Claudio Pisa <clauz@ninux.org>
# Released under the GNU General Public License v3

# This script outputs a wireless scan survey including the hostnames which are broadcast
# in ubiquiti (and other vendors') beacons (OUI 00:0c:42).

DEV="$1"

if [ -z "$DEV" ]; then
    echo -e "\t\tUsage: $0 <wlan device>"
    echo -e "\t\te.g.   $0 wlan0"
    exit 1
fi

SCAN="$(iw dev $DEV scan -u)"

# optimization
SCAN="$(echo "$SCAN" | grep 'BSS\|signal:\|SSID:\|freq:\|OUI 00:0c:42')"

# offset for the hostname in the 802.11 beacon IE
OFFSET=15

BSS=""
SSID=""
CHANNEL=""
HNAME=""
SIGNAL=""

# we want a list of SSID, CHANNEL, HOSTNAME
printf "%20s%30s%14s%8s%20s\n" "BSS" "SSID" "SIGNAL" "FREQ" "HOSTNAME"
echo -e "${SCAN}\nEOF" | while read line; do
    if [ "$line" == "EOF" ]; then
            printf "%20s%30s%14s%8s%20s\n" "$BSS" "$SSID" "$SIGNAL" "$CHANNEL" "$HNAME"
	    break
    fi
    B="$(echo "$line" | egrep "^BSS" | grep -v 'Load' | awk '{print $2}' | sed 's/(.*$//')"
    if [ -n "$B" ]; then
        if [ -n "$BSS" ]; then
            printf "%20s%30s%14s%8s%20s\n" "$BSS" "$SSID" "$SIGNAL" "$CHANNEL" "$HNAME"
            BSS=""
            SSID=""
            CHANNEL=""
            HNAME=""
            SIGNAL=""
        fi
        BSS="$B"
    fi

    S="$(echo "$line" | grep "SSID:" | awk -F":" '{print $2}')"
    if [ -n "$S" ]; then
        SSID="$S"
    fi

    C="$(echo "$line" | grep "freq:" | awk -F":" '{print $2}')"
    if [ -n "$C" ]; then
        CHANNEL="$C"
    fi
    
    G="$(echo "$line" | grep "signal:" | awk -F":" '{print $2}')"
    if [ -n "$G" ]; then
        SIGNAL="$G"
    fi

    # OUI 00:0c:42 contains the information element
    T="$(echo "$line" | grep "OUI 00:0c:42" | sed 's/.*data: \(.*\)/\1/g' )"
    if [ -n "$T" ]; then
        H=""
        cur=0
        for t in $T; do
            cur=$((cur+1))
            if [ $cur -gt $OFFSET ]; then
                if [ -n "$t" ] && [ "$t" != "00" ]; then
                    H0=$(printf "\x$t")
                    H="${H}${H0}"
                fi
            fi
        done
        HNAME="$H"
    fi
done