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     echo "  Scanning ..."
  74     iwconfig ${INTERFACE} ap off essid ""
  75     iwlist ${INTERFACE} scan | \
  76         sed -e "s/^[\t ]*//"  | grep ^"Cell\|ESSID\|Quality\|Encryption" | \
  77         sed \
  78         -e "s/Cell [0-9]* - Address: \([0-9]*\)/AP,\1/" \
  79         -e "s/^ *ESSID:\\\"\([^\\\"]*\)\\\".*$/ESSID,\1/" \
  80         -e "s/Quality=\([0-9]*\).*$/QUALITY,\1/" \
  81         -e "s/Encryption key:/ENCRYPTION,/" | \
  82         awk 'BEGIN { FS="," }
  83          {
  84            if($1 == "ESSID") { essid=$2 }
  85            else if($1 == "AP") { ap=$2 }
  86            else if($1 == "QUALITY") { quality=$2; }
  87            else if($1 == "ENCRYPTION") {
  88              if($2 == "off") {
  89                open="        "
  90                printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  91              } else {
  92                if('${SHOW_CLOSED}') {
  93                  open="(closed)"
  94                  printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  95                }
  96              }
  97            }
  98          }' | \
  99              sort -rn > ${SCAN_OUTPUT}
 100
 101     number_of_aps=$(wc -l ${SCAN_OUTPUT} | awk '{print $1}')
 102
 103     chmod a+rw ${SCAN_OUTPUT}
 104 }
 105
 106 function redisplay () {
 107     clear
 108
 109     echo
 110     echo -n "  ${VT_UNDERLINE}Hotspot selection${VT_RESET}"
 111     if [[ $SHOW_CLOSED == 0 ]]; then
 112         echo " (show only open networks)"
 113     else
 114         echo
 115     fi
 116     echo
 117     echo "  [s,r] scan  [m] switch the free-only view and scan    [q] quit"
 118     echo "  [e] select essid + dhcp  [a] selects essid/ap + dhcp  [k] kill dhcp and quit"
 119     echo
 120
 121     for i in $(ifconfig -s | grep -E -v ^lo\|Iface\|wmaster | awk '{print $1}'); do
 122         echo "  Warning: $i is up"
 123     done
 124     echo
 125
 126     if [[ ${number_of_aps} == "0" ]]; then
 127         echo "  ${VT_RED_FG}${VT_BOLD}No access point detected.${VT_RESET}"
 128     else
 129
 130         awk < ${SCAN_OUTPUT} 'BEGIN { nb=1; FS="," }
 131          {
 132              if(nb == '$current_ap') {
 133                printf(" =>");
 134              } else {
 135                printf("   ");
 136              }
 137              if($2 == "(closed)") {
 138                printf("'${VT_RED_FG}'");
 139                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 140                  } else {
 141                printf("'${VT_GREEN_FG}'");
 142                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 143              }
 144              nb=nb+1;
 145          }'
 146     fi
 147 }
 148
 149 function get-selected-essid-ap () {
 150     cat ${SCAN_OUTPUT}  | \
 151         awk 'BEGIN { nb=1; FS="," }
 152          {
 153              if(nb == '$current_ap') {
 154                printf("%s,%s\n", $3, $4);
 155              }
 156              nb=nb+1;
 157          }'
 158 }
 159
 160 function kill-dhcp () {
 161     PID=$(pidof dhclient)
 162     if [[ ${PID} ]]; then
 163         echo "Killing dhclient"
 164         dhclient -x ${INTERFACE}
 165     fi
 166 }
 167
 168 ######################################################################
 169
 170 function process-key () {
 171
 172     case $1 in
 173         e) # Selects essid + dhcp
 174             SELECTED=$(get-selected-essid-ap)
 175             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 176             echo "Running DHCP on ${INTERFACE} for ESSID ${ESSID}."
 177             iwconfig ${INTERFACE} ap auto essid "${ESSID}"
 178             kill-dhcp
 179             echo
 180             dhclient ${INTERFACE}
 181             # if [[ $? == 0 ]]; then
 182                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 183             # fi
 184             ifconfig ${INTERFACE} mtu ${MTU}
 185             interface_was_up=1
 186             cont=0
 187             ;;
 188
 189         "return"|a) # Selects essid/ap + dhcp
 190             SELECTED=$(get-selected-essid-ap)
 191             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 192             AP=$(echo ${SELECTED} | cut -f 2 -d,)
 193             echo "Running DHCP on ${INTERFACE} for ESSID ${ESSID} and AP ${AP}."
 194             iwconfig ${INTERFACE} ap ${AP} essid "${ESSID}"
 195             kill-dhcp
 196             echo
 197             dhclient ${INTERFACE}
 198             # if [[ $? == 0 ]]; then
 199                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 200             # fi
 201             ifconfig ${INTERFACE} mtu ${MTU}
 202             interface_was_up=1
 203             cont=0
 204             ;;
 205
 206         k) # kill dhcp
 207             echo "Killing DHCP and bringing down ${INTERFACE}."
 208             kill-dhcp
 209             ifconfig ${INTERFACE} down
 210             cont=0
 211             ;;
 212
 213         r|s) # re-scanning the access points
 214             scan
 215             redisplay
 216             ;;
 217
 218         m) # Switching the mode to show the protected spots
 219             SHOW_CLOSED=$((1-SHOW_CLOSED))
 220             scan
 221             redisplay
 222             ;;
 223
 224         "down"|n)
 225             current_ap=$((current_ap+1))
 226             if [[ $current_ap -gt $number_of_aps ]]; then
 227                 current_ap=$number_of_aps
 228             fi
 229             redisplay
 230             ;;
 231
 232         "up"|p)
 233             current_ap=$((current_ap-1))
 234             if [[ $current_ap -lt 1 ]]; then
 235                 current_ap=1
 236             fi
 237             redisplay
 238             ;;
 239
 240         "esc-esc"|q)
 241             echo "  Quit."
 242             cont=0
 243             ;;
 244
 245         *)
 246             ;;
 247     esac
 248 }
 249
 250 ######################################################################
 251 ## The main
 252
 253 if [[ $1 == "-k" ]]; then
 254     echo "Killing DHCP and bringing down ${INTERFACE}."
 255     kill-dhcp
 256     ifconfig ${INTERFACE} down
 257     exit 1
 258 fi
 259
 260 stty_state=$(stty -g)
 261
 262 trap sigint-handler SIGHUP SIGINT SIGQUIT SIGABRT SIGTERM
 263
 264 stty -echo -icrnl -icanon -xcase min 1 time 0
 265
 266 echo ${VT_CURSOR_OFF}
 267
 268 current_ap=1
 269 cont=1
 270 current_keymap=default
 271
 272 interface_was_up=$(ifconfig | grep ${INTERFACE})
 273
 274 ifconfig ${INTERFACE} up
 275
 276 scan
 277
 278 redisplay
 279
 280 while [[ ${cont} == 1 ]]; do
 281
 282     CHAR=$(dd bs=1 count=1 2>/dev/null)
 283
 284     case ${current_keymap} in
 285         default) ##################################################
 286             case ${CHAR} in
 287
 288                 [a-z])
 289                     process-key ${CHAR}
 290                     ;;
 291
 292                 "\r")
 293                     process-key "return"
 294                     ;;
 295
 296                 "\ e")
 297                 process-key "down"
 298                 ;;
 299
 300                 "\10")
 301                 process-key "up"
 302                 ;;
 303
 304                 "\e") #$'\033'")
 305                 current_keymap=escape
 306                 ;;
 307
 308                 *)
 309                 ;;
 310                 esac
 311                 ;;
 312
 313                 escape) ##################################################
 314                 case ${CHAR} in
 315                     "$'\033'")
 316                     process-key "esc-esc"
 317                     ;;
 318                     "[")
 319                     current_keymap=cursor
 320                     ;;
 321                     *)
 322                     current_keymap=default
 323                     ;;
 324                 esac
 325                 ;;
 326
 327                 cursor) ##################################################
 328
 329                 current_keymap=default
 330
 331                 case ${CHAR} in
 332                     A)
 333                     process-key "up"
 334                     ;;
 335                     B)
 336                     process-key "down"
 337                     ;;
 338                     *)
 339                     ;;
 340                 esac
 341                 ;;
 342
 343                 *)
 344                 echo "Unknown keymap. This is an internal and weird bug."
 345                 cont=0
 346                 ;;
 347                 esac
 348
 349                 done
 350
 351                 cleanup-before-quit