raspberryap

#!/bin/bash
### BEGIN INIT INFO
# Provides: raspberryap
# Required-Start: $all
# Required-Stop:
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
#### END INIT INFO
set -u

readonly F_CONFIG_DIR='/tmp/raspberryap'
readonly F_TMP_DIR="$F_CONFIG_DIR/tmp"

readonly F_CONFIG='/etc/raspberryap.conf'
readonly F_CONFIG_HOSTAPD="$F_CONFIG_DIR/hostapd.conf"
readonly F_CONFIG_DNSMASQ="$F_CONFIG_DIR/dnsmasq.conf"

readonly F_HOSTAPD_LOG="$F_TMP_DIR/hostapd.log"
readonly F_PID="$F_TMP_DIR/pid"

readonly MAX_CHANNEL=13
readonly KEY_WORD=('INTERFACE' 'TYPE_ESSID' 'ESSID' 'WPA' 'CHANNEL' 'ESSID_CHECK' 'RX_MAX' 'FORCE_RESCAN')

INTERFACE=
ESSID_CHECK=()
WPA_FILE=
CHANNEL="$(($(($RANDOM % $MAX_CHANNEL)) + 1))"
ESSID_AP=
TYPE_ESSID=0
WPA=
RX_MAX=68
FORCE_RESCAN=0

function flush_interface() {
   rfkill unblock all
   dhclient -r $INTERFACE &>/dev/null
   killall -g wpa_supplicant &>/dev/null
   ifdown $INTERFACE &>/dev/null
   ifconfig $INTERFACE down &>/dev/null
   ip addr flush dev $INTERFACE &>/dev/null
   ifconfig $INTERFACE up &>/dev/null
}

function kill_service() {
   service NetworkManager stop &>/dev/null
   service wicd stop &>/dev/null
   service dnsmasq stop &>/dev/null
   service hostapd stop &>/dev/null
   killall -g dnsmasq &>/dev/null
   killall -g hostapd &>/dev/null
}

function help() {
   echo "Usage: $0 check_conf|start|stop"
}

function check_dependencies() {
   if ! command -v rfkill &>/dev/null || ! command -v hostapd &>/dev/null || ! command -v dnsmasq &>/dev/null || ! command -v iw &>/dev/null || ! command -v iwconfig &>/dev/null || ! command -v wpa_supplicant &>/dev/null; then
      echo "Errore. Mancano alcune dipendenze"
      exit 1
   fi
}

function check_file_config() {
   if [ ! -f $F_CONFIG ]; then
      echo "File di configurazione '$F_CONFIG' non trovato"
      exit 1
   fi

   F_TMP="$(grep -Ev '^#|^$' $F_CONFIG | sed 's/^[[:space:]]*//')"

   if echo $F_TMP | cut -d'=' -f 1 | grep '^[a-z]*$' &>/dev/null; then
      echo "Errore. Le keyword evono essere tutte in maiuscolo"
      exit 1
   fi

   while read key_word; do
      keyword="$(echo "$key_word" | cut -d'=' -f1)"

      case "$keyword" in
      'INTERFACE')
         INTERFACE="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2)"

         if [ -z $INTERFACE ]; then
            echo "Valore nullo per '$keyword'"
            exit 1
         fi

         check_interface
         ;;

      'ESSID')
         ESSID_AP="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2)"
         if [ -z $ESSID_AP ]; then
            echo "Valore nullo per '$keyword'"
            exit 1
         fi
         ;;

      'TYPE_ESSID')
         TYPE_ESSID="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2 | grep -E '^0$|^1$')"

         if [ -z $TYPE_ESSID ]; then
            echo "Valore nullo per '$keyword'"
            exit 1
         fi

         if [ $TYPE_ESSID -gt 1 ]; then
            echo "Valore non valido per '$keyword': accetta '0', '1'"
            exit 1
         fi
         ;;

      'WPA')
         WPA="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2 | grep -E '^.{8,63}$')"
         if [ -z $WPA ]; then
            echo "Valore non valido in '$keyword'. PS. (almeno 8 caratteri)"
            exit 1
         fi
         ;;

      'CHANNEL')
         CHANNEL="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2 | grep '^[0-9]*$')"
         if [ -z $CHANNEL ]; then
            echo "Valore non valido in '$keyword'"
            exit 1
         fi

         if [ $CHANNEL -gt $MAX_CHANNEL ]; then
            echo "Errore. Il valore CHANNEL deve essere compreso tra 1 e $MAX_CHANNEL"
            exit 1
         fi
         ;;

      'RX_MAX')
         RX_MAX="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2 | grep -E '^(^|[^0-9])[0-9]{1,2}($|[^0-9])')"
         if [ -z $RX_MAX ]; then
            echo "Valore non valido in '$keyword'"
            exit 1
         fi
         ;;

      'ESSID_CHECK')
         arg_keyword="$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2)"
         if [ -z $arg_keyword ]; then
            echo "Valore nullo per '$keyword'"
            exit 1
         fi

         ifs=$IFS
         IFS=','
         for essid in $(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2); do
            WPA_FILE="$(echo "$essid" | cut -d':' -f2)"

            if [ ! -f "$WPA_FILE" ]; then
               echo "File di configurazione wpa '$WPA_FILE' non trovato"
               exit 1
            fi

            ESSID_CHECK+=($essid)
         done
         IFS=$ifs
         ;;

      'FORCE_RESCAN')
         FORCE_RESCAN=$(echo "$key_word" | grep "^\<$keyword\>" | cut -d'=' -f2 | grep '^[0-9]*$')

         if [ -z $FORCE_RESCAN ]; then
            echo "Valore nullo per '$keyword'"
            exit 1
         fi
         ;;

      * | ?)
         echo "Errore. Keyword '$keyword' non valida"
         exit 1
         ;;
      esac
   done <<<$F_TMP

   if [ -z $INTERFACE ]; then
      echo "Manca l'opzione INTERFACE nel file di configurazione"
      exit 1
   fi

   if [ -z $ESSID_AP ]; then
      echo "Manca l'opzione ESSID nel file di configurazione"
      exit 1
   fi
}

function check_interface() {
   phy_interface="$(cat /sys/class/net/$INTERFACE/phy80211/name)"

   if ! find /sys/class/net/ ! -type d | grep "\<$INTERFACE\>" &>/dev/null; then
      echo "L'interfaccia '$INTERFACE' non esiste"
      exit 1
   fi

   iw $phy_interface info | grep 'AP$' &>/dev/null

   if [ "$?" != "0" ]; then
      echo "L'interfaccia '$INTERFACE' non supporta la modalità AP"
      exit 1
   fi
}

function connection_ap() {
   total_essid_check=${#ESSID_CHECK[@]}
   ESSID_CONNECT=

   for essid in $(seq 0 $(($total_essid_check - 1))); do
      essid_check="$(echo ${ESSID_CHECK[$essid]} | cut -d':' -f1)"

      SCAN_RESULT="$(iwlist $INTERFACE scan 2>/dev/null | expand | grep -B2 'ESSID' | grep -B2 "\"\<$essid_check\>\"\$" | sed 's/^[[:space:]]*//')"
      if [ ! -z "$SCAN_RESULT" ]; then
         echo "* Trovato ESSID '$essid_check'"

         signal_cap="$(echo "$SCAN_RESULT" | head -n1 | sed 's/^.*Signal level=//; s/[-a-zA-Z ]//g' | awk '{print $1}')"
         if [ $signal_cap -gt $RX_MAX ]; then
            echo "[!] Ricezione del segnale debole per l'essid '$essid_check'"
         else
            WPA_FILE="$(echo ${ESSID_CHECK[$essid]} | cut -d':' -f2)"
            ESSID_CONNECT="$essid_check"
            break
         fi
      fi
   done

   if [ ! -z $ESSID_CONNECT ]; then
      wpa_supplicant -i $INTERFACE -c $WPA_FILE -B &>/dev/null && dhclient $INTERFACE

      if [ "$?" == "0" ]; then
         echo "* Connessione riuscita"
      else
         echo "[!] Errore nella connessione"
         flush_interface
         kill_service
         return 1
      fi

   else
      return 1
   fi

   return 0
}

function creation_ap() {
   # `hostapd` Configuring
   echo -e "interface=$INTERFACE\n" \
      "driver=nl80211\n" \
      "ssid=$ESSID_AP\n" \
      "hw_mode=g\n" \
      "channel=$CHANNEL\n" \
      "auth_algs=1\n" \
      "ignore_broadcast_ssid=$TYPE_ESSID" | sed 's/^[[:space:]]*//' >$F_CONFIG_HOSTAPD

   if [ ! -z $WPA ]; then
      echo -e "macaddr_acl=0\n" \
         "wpa=2\n" \
         "wpa_passphrase=$WPA\n" \
         "wpa_key_mgmt=WPA-PSK\n" \
         "wpa_pairwise=CCMP TKIP\n" \
         "rsn_pairwise=CCMP" | sed 's/^[[:space:]]*//' >>$F_CONFIG_HOSTAPD
   fi

   # `dnsmasq` Configuring
   echo -e "interface=$INTERFACE\n" \
      "bind-interfaces\n" \
      "dhcp-authoritative\n" \
      "dhcp-range=192.168.2.2,192.168.2.254,3h\n" \
      "dhcp-option=option:router,192.168.2.1\n" \
      "server=192.168.2.1" | sed 's/^[[:space:]]*//' >$F_CONFIG_DNSMASQ

   rm -rf $F_HOSTAPD_LOG
   if hostapd -B $F_CONFIG_HOSTAPD -f $F_HOSTAPD_LOG && ifconfig $INTERFACE 192.168.2.1 netmask 255.255.255.0 && dnsmasq -C $F_CONFIG_DNSMASQ; then
      echo "* Creazione AP riuscita"
   else
      echo "[!] Problema nella creazione dell'AP"
      kill_service
      flush_interface
      return 1
   fi

   return 0
}

## MAIN ##
if [ $EUID -ne 0 ]; then
   echo "Bisogna essere amminstratori per lanciare lo script"
   exit 1
fi

check_dependencies

mkdir $F_CONFIG_DIR &>/dev/null
mkdir $F_TMP_DIR &>/dev/null

if [ $# -eq 0 ]; then
   help
   exit 1
fi

case "$1" in
check_conf)
   check_file_config || exit 1
   ;;

start)
   check_file_config || exit 1

   kill_service
   flush_interface

   connection_ap || creation_ap

   if [ $FORCE_RESCAN -gt 0 ]; then
      (while [ 1 ]; do
         echo "+ Riscansione tra $FORCE_RESCAN minuti..."

         sleep $(($FORCE_RESCAN * 60))

         status=$(iwconfig wlan0 | expand | sed 's/[[:space:]]/\n/g; s/^[[:space:]]*//' | grep 'Mode:' | cut -d':' -f2)
         if [ "$status" == "Master" ]; then
            if [ $(grep '\-CONNECTED' $F_HOSTAPD_LOG | wc -l) -eq $(grep '\-DISCONNECTED' $F_HOSTAPD_LOG | wc -l) ]; then
               echo "+ Spegnimento AP..."
               kill_service
               flush_interface

               ifconfig $INTERFACE down
               iwconfig $INTERFACE mode managed
               ifconfig $INTERFACE up

               connection_ap || creation_ap
            fi
         else
            if [ "$(iwconfig wlan0 | expand | sed 's/[[:space:]]/\n/g; s/^[[:space:]]*//' | grep ESSID | cut -d':' -f 2)" == "off/any" ]; then
               killall -g wpa_supplicant &>/dev/null
               flush_interface
               connection_ap || creation_ap
            fi
         fi
      done) &
      echo $! >"$F_PID"
   fi
   ;;

stop)
   kill -TERM $(cat "$F_PID") &>/dev/null
   kill_service
   flush_interface
   ;;

* | ?)
   help
   exit 1
   ;;
esac

exit 0