hotspot.sh

   1 #!/bin/bash
   2
   3 #########################################################################
   4 # This program is free software: you can redistribute it and/or modify  #
   5 # it under the terms of the version 3 of the GNU General Public License #
   6 # as published by the Free Software Foundation.                         #
   7 #                                                                       #
   8 # This program is distributed in the hope that it will be useful, but   #
   9 # WITHOUT ANY WARRANTY; without even the implied warranty of            #
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      #
  11 # General Public License for more details.                              #
  12 #                                                                       #
  13 # You should have received a copy of the GNU General Public License     #
  14 # along with this program. If not, see <http://www.gnu.org/licenses/>.  #
  15 #                                                                       #
  16 # Written by and Copyright (C) Francois Fleuret                         #
  17 # Contact <francois@fleuret.org> for comments & bug reports             #
  18 #########################################################################
  19
  20 INTERFACE=wlan0
  21 MTU=512
  22
  23 SCAN_OUTPUT=$(mktemp /tmp/scanresult.XXXXXX)
  24 SHOW_CLOSED=0
  25
  26 ######################################################################
  27
  28 VT_CURSOR_OFF=$'\033[?25l'
  29 VT_CURSOR_ON=$'\033[?25h'
  30
  31 VT_RESET=$'\033[0m'
  32 VT_BOLD=$'\033[1m'
  33 VT_UNDERLINE=$'\033[4m'
  34 VT_BLINK=$'\033[5m'
  35
  36 VT_BLACK_FG=$'\033[30m'
  37 VT_RED_FG=$'\033[31m'
  38 VT_GREEN_FG=$'\033[32m'
  39 VT_YELLOW_FG=$'\033[33m'
  40 VT_BLUE_FG=$'\033[34m'
  41 VT_MAGENTA_FG=$'\033[35m'
  42 VT_CYAN_FG=$'\033[36m'
  43 VT_WHITE_FG=$'\033[37m'
  44
  45 VT_BLACK_BG=$'\033[40m'
  46 VT_RED_BG=$'\033[41m'
  47 VT_GREEN_BG=$'\033[42m'
  48 VT_YELLOW_BG=$'\033[43m'
  49 VT_BLUE_BG=$'\033[44m'
  50 VT_MAGENTA_BG=$'\033[45m'
  51 VT_CYAN_BG=$'\033[46m'
  52 VT_WHITE_BG=$'\033[47m'
  53
  54 ######################################################################
  55
  56 function cleanup-before-quit () {
  57     echo ${VT_CURSOR_ON}
  58     stty "$stty_state"
  59     rm -f ${SCAN_OUTPUT}
  60     if [[ "${interface_was_up}" == "" ]]; then
  61         echo "The interface was down."
  62         ifconfig ${INTERFACE} down
  63     fi
  64 }
  65
  66 function sigint-handler () {
  67     cleanup-before-quit
  68     echo "Interrupted"
  69     exit 0
  70 }
  71
  72 function scan () {
  73     iwconfig ${INTERFACE} ap off essid ""
  74     iwlist ${INTERFACE} scan | \
  75         sed -e "s/^[\t ]*//"  | grep ^"Cell\|ESSID\|Quality\|Encryption" | \
  76         sed \
  77         -e "s/Cell [0-9]* - Address: \([0-9]*\)/AP,\1/" \
  78         -e "s/^ *ESSID:\\\"\([^\\\"]*\)\\\".*$/ESSID,\1/" \
  79         -e "s/Quality=\([0-9]*\).*$/QUALITY,\1/" \
  80         -e "s/Encryption key:/ENCRYPTION,/" | \
  81         awk 'BEGIN { FS="," }
  82          {
  83            if($1 == "ESSID") { essid=$2 }
  84            else if($1 == "AP") { ap=$2 }
  85            else if($1 == "QUALITY") { quality=$2; }
  86            else if($1 == "ENCRYPTION") {
  87              if($2 == "off") {
  88                open="        "
  89                printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  90              } else {
  91                if('${SHOW_CLOSED}') {
  92                  open="(closed)"
  93                  printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  94                }
  95              }
  96            }
  97          }' | \
  98              sort -rn > ${SCAN_OUTPUT}
  99
 100     number_of_aps=$(wc -l ${SCAN_OUTPUT} | awk '{print $1}')
 101
 102     chmod a+rw ${SCAN_OUTPUT}
 103 }
 104
 105 function redisplay () {
 106     clear
 107
 108     echo
 109     echo -n "  ${VT_UNDERLINE}Hotspot selection${VT_RESET}"
 110     if [[ $SHOW_CLOSED == 0 ]]; then
 111         echo " (show only open networks)"
 112     else
 113         echo
 114     fi
 115     echo
 116     echo "  [s,r] scan  [m] switch the free-only view and scan    [q] quit"
 117     echo "  [e] select essid + dhcp  [a] selects essid/ap + dhcp  [k] kill dhcp and quit"
 118     echo
 119
 120     for i in $(ifconfig -s | grep -E -v ^lo\|Iface\|wmaster | awk '{print $1}'); do
 121         echo "  Warning: $i is up"
 122     done
 123     echo
 124
 125     if [[ ${number_of_aps} == "0" ]]; then
 126         echo "  ${VT_RED_FG}${VT_BOLD}No access point detected.${VT_RESET}"
 127     else
 128
 129         awk < ${SCAN_OUTPUT} 'BEGIN { nb=1; FS="," }
 130          {
 131              if(nb == '$current_ap') {
 132                printf(" =>");
 133              } else {
 134                printf("   ");
 135              }
 136              if($2 == "(closed)") {
 137                printf("'${VT_RED_FG}'");
 138                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 139                  } else {
 140                printf("'${VT_GREEN_FG}'");
 141                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 142              }
 143              nb=nb+1;
 144          }'
 145     fi
 146 }
 147
 148 function get-selected-essid-ap () {
 149     cat ${SCAN_OUTPUT}  | \
 150         awk 'BEGIN { nb=1; FS="," }
 151          {
 152              if(nb == '$current_ap') {
 153                printf("%s,%s\n", $3, $4);
 154              }
 155              nb=nb+1;
 156          }'
 157 }
 158
 159 function kill-dhcp () {
 160     PID=$(pidof dhclient)
 161     if [[ ${PID} ]]; then
 162         echo "Killing dhclient"
 163         dhclient -x ${INTERFACE}
 164     fi
 165 }
 166
 167 ######################################################################
 168
 169 function process-key () {
 170
 171     case $1 in
 172         e) # Selects essid + dhcp
 173             SELECTED=$(get-selected-essid-ap)
 174             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 175             echo "Running DHCP on ${INTERFACE} for ESSID ${ESSID}."
 176             iwconfig ${INTERFACE} ap auto essid "${ESSID}"
 177             kill-dhcp
 178             echo
 179             dhclient ${INTERFACE}
 180             # if [[ $? == 0 ]]; then
 181                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 182             # fi
 183             ifconfig ${INTERFACE} mtu ${MTU}
 184             interface_was_up=1
 185             cont=0
 186             ;;
 187
 188         "return"|a) # Selects essid/ap + dhcp
 189             SELECTED=$(get-selected-essid-ap)
 190             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 191             AP=$(echo ${SELECTED} | cut -f 2 -d,)
 192             echo "Running DHCP on ${INTERFACE} for ESSID ${ESSID} and AP ${AP}."
 193             iwconfig ${INTERFACE} ap ${AP} essid "${ESSID}"
 194             kill-dhcp
 195             echo
 196             dhclient ${INTERFACE}
 197             # if [[ $? == 0 ]]; then
 198                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 199             # fi
 200             ifconfig ${INTERFACE} mtu ${MTU}
 201             interface_was_up=1
 202             cont=0
 203             ;;
 204
 205         k) # kill dhcp
 206             echo "Killing DHCP and bringing down ${INTERFACE}."
 207             kill-dhcp
 208             ifconfig ${INTERFACE} down
 209             cont=0
 210             ;;
 211
 212         r|s) # re-scanning the access points
 213             echo "Scanning ..."
 214             scan
 215             redisplay
 216             ;;
 217
 218         m) # Switching the mode to show the protected spots
 219             SHOW_CLOSED=$((1-SHOW_CLOSED))
 220             echo "Scanning ..."
 221             scan
 222             redisplay
 223             ;;
 224
 225         "down"|n)
 226             current_ap=$((current_ap+1))
 227             if [[ $current_ap -gt $number_of_aps ]]; then
 228                 current_ap=$number_of_aps
 229             fi
 230             redisplay
 231             ;;
 232
 233         "up"|p)
 234             current_ap=$((current_ap-1))
 235             if [[ $current_ap -lt 1 ]]; then
 236                 current_ap=1
 237             fi
 238             redisplay
 239             ;;
 240
 241         "esc-esc"|q)
 242             echo "quit"
 243             cont=0
 244             ;;
 245
 246         *)
 247             ;;
 248     esac
 249 }
 250
 251 ######################################################################
 252 ## The main
 253
 254 if [[ $1 == "-k" ]]; then
 255     echo "Killing DHCP and bringing down ${INTERFACE}."
 256     kill-dhcp
 257     ifconfig ${INTERFACE} down
 258     exit 1
 259 fi
 260
 261 stty_state=$(stty -g)
 262
 263 trap sigint-handler SIGHUP SIGINT SIGQUIT SIGABRT SIGTERM
 264
 265 stty -echo -icrnl -icanon -xcase min 1 time 0
 266
 267 echo ${VT_CURSOR_OFF}
 268
 269 current_ap=1
 270 cont=1
 271 current_keymap=default
 272
 273 interface_was_up=$(ifconfig | grep ${INTERFACE})
 274
 275 ifconfig ${INTERFACE} up
 276
 277 scan
 278
 279 redisplay
 280
 281 while [[ ${cont} == 1 ]]; do
 282
 283     CHAR=$(dd bs=1 count=1 2>/dev/null)
 284
 285     case ${current_keymap} in
 286         default) ##################################################
 287             case ${CHAR} in
 288
 289                 [a-z])
 290                     process-key ${CHAR}
 291                     ;;
 292
 293                 "\r")
 294                     process-key "return"
 295                     ;;
 296
 297                 "\ e")
 298                 process-key "down"
 299                 ;;
 300
 301                 "\10")
 302                 process-key "up"
 303                 ;;
 304
 305                 "\e") #$'\033'")
 306                 current_keymap=escape
 307                 ;;
 308
 309                 *)
 310                 ;;
 311                 esac
 312                 ;;
 313
 314                 escape) ##################################################
 315                 case ${CHAR} in
 316                     "$'\033'")
 317                     process-key "esc-esc"
 318                     ;;
 319                     "[")
 320                     current_keymap=cursor
 321                     ;;
 322                     *)
 323                     current_keymap=default
 324                     ;;
 325                 esac
 326                 ;;
 327
 328                 cursor) ##################################################
 329
 330                 current_keymap=default
 331
 332                 case ${CHAR} in
 333                     A)
 334                     process-key "up"
 335                     ;;
 336                     B)
 337                     process-key "down"
 338                     ;;
 339                     *)
 340                     ;;
 341                 esac
 342                 ;;
 343
 344                 *)
 345                 echo "Unknown keymap. This is an internal and weird bug."
 346                 cont=0
 347                 ;;
 348                 esac
 349
 350                 done
 351
 352                 cleanup-before-quit