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=${WIFI_INTERFACE}
  21
  22 [[ ${INTERFACE} ]] || INTERFACE=wlan0
  23
  24 MTU=512
  25
  26 SCAN_OUTPUT=$(mktemp /tmp/scanresult.XXXXXX)
  27 SHOW_CLOSED=0
  28
  29 ######################################################################
  30
  31 VT_CURSOR_OFF=$'\033[?25l'
  32 VT_CURSOR_ON=$'\033[?25h'
  33
  34 VT_RESET=$'\033[0m'
  35 VT_BOLD=$'\033[1m'
  36 VT_UNDERLINE=$'\033[4m'
  37 VT_BLINK=$'\033[5m'
  38
  39 VT_BLACK_FG=$'\033[30m'
  40 VT_RED_FG=$'\033[31m'
  41 VT_GREEN_FG=$'\033[32m'
  42 VT_YELLOW_FG=$'\033[33m'
  43 VT_BLUE_FG=$'\033[34m'
  44 VT_MAGENTA_FG=$'\033[35m'
  45 VT_CYAN_FG=$'\033[36m'
  46 VT_WHITE_FG=$'\033[37m'
  47
  48 VT_BLACK_BG=$'\033[40m'
  49 VT_RED_BG=$'\033[41m'
  50 VT_GREEN_BG=$'\033[42m'
  51 VT_YELLOW_BG=$'\033[43m'
  52 VT_BLUE_BG=$'\033[44m'
  53 VT_MAGENTA_BG=$'\033[45m'
  54 VT_CYAN_BG=$'\033[46m'
  55 VT_WHITE_BG=$'\033[47m'
  56
  57 ######################################################################
  58
  59 function cleanup-before-quit () {
  60     echo ${VT_CURSOR_ON}
  61     stty "$stty_state"
  62     rm -f ${SCAN_OUTPUT}
  63     if [[ "${interface_was_up}" == "" ]]; then
  64         echo "The interface was down."
  65         ifconfig ${INTERFACE} down
  66     fi
  67 }
  68
  69 function sigint-handler () {
  70     cleanup-before-quit
  71     echo "Interrupted"
  72     exit 0
  73 }
  74
  75 function scan () {
  76     echo
  77     echo "  Scanning ..."
  78     iwconfig ${INTERFACE} ap off essid ""
  79     iwlist ${INTERFACE} scan | \
  80         sed -e "s/^[\t ]*//"  | grep ^"Cell\|ESSID\|Quality\|Encryption" | \
  81         sed \
  82         -e "s/Cell [0-9]* - Address: \([0-9]*\)/AP,\1/" \
  83         -e "s/^ *ESSID:\\\"\([^\\\"]*\)\\\".*$/ESSID,\1/" \
  84         -e "s/Quality=\([0-9]*\).*$/QUALITY,\1/" \
  85         -e "s/Encryption key:/ENCRYPTION,/" | \
  86         awk 'BEGIN { FS="," }
  87                                                                                         {
  88                                                                                             if($1 == "ESSID") { essid=$2 }
  89            else if($1 == "AP") { ap=$2 }
  90            else if($1 == "QUALITY") { quality=$2; }
  91            else if($1 == "ENCRYPTION") {
  92              if($2 == "off") {
  93                open="        "
  94                printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  95              } else {
  96                if('${SHOW_CLOSED}') {
  97                  open="(closed)"
  98                  printf("%d,%s,%s,%s\n",quality,open,essid,ap);
  99                }
 100              }
 101            }
 102          }' | \
 103              sort -rn > ${SCAN_OUTPUT}
 104
 105     number_of_aps=$(wc -l ${SCAN_OUTPUT} | awk '{print $1}')
 106
 107     chmod a+rw ${SCAN_OUTPUT}
 108 }
 109
 110 function redisplay () {
 111     clear
 112
 113     echo
 114     echo -n "  ${VT_UNDERLINE}Hotspot selection${VT_RESET}"
 115     if [[ $SHOW_CLOSED == 0 ]]; then
 116         echo " (show only open networks)"
 117     else
 118         echo
 119     fi
 120     echo
 121     echo "  [s,r] scan  [m] switch the free-only view and scan    [q] quit"
 122     echo "  [e] select essid + dhcp  [a] selects essid/ap + dhcp  [k] kill dhcp and quit"
 123     echo
 124
 125     for i in $(ifconfig -s | grep -E -v ^lo\|Iface\|wmaster | awk '{print $1}'); do
 126         echo "  Warning: $i is up"
 127     done
 128     echo
 129
 130     if [[ ${number_of_aps} == "0" ]]; then
 131         echo "  ${VT_RED_FG}${VT_BOLD}No access point detected.${VT_RESET}"
 132     else
 133
 134         awk < ${SCAN_OUTPUT} 'BEGIN { nb=1; FS="," }
 135          {
 136              if(nb == '$current_ap') {
 137                printf(" =>");
 138              } else {
 139                printf("   ");
 140              }
 141              if($2 == "(closed)") {
 142                printf("'${VT_RED_FG}'");
 143                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 144                  } else {
 145                printf("'${VT_GREEN_FG}'");
 146                printf("% 3s %s \"%s\" %s'${VT_RESET}'\n", $1, $2, $3, $4);
 147              }
 148              nb=nb+1;
 149          }'
 150     fi
 151 }
 152
 153 function get-selected-essid-ap () {
 154     cat ${SCAN_OUTPUT}  | \
 155         awk 'BEGIN { nb=1; FS="," }
 156          {
 157              if(nb == '$current_ap') {
 158                printf("%s,%s\n", $3, $4);
 159              }
 160              nb=nb+1;
 161          }'
 162 }
 163
 164 function kill-dhcp () {
 165     PID=$(pidof dhclient)
 166     if [[ ${PID} ]]; then
 167         echo "Killing dhclient"
 168         dhclient -x ${INTERFACE}
 169     fi
 170 }
 171
 172 ######################################################################
 173
 174 function process-key () {
 175
 176     case $1 in
 177         e) # Selects essid + dhcp
 178             SELECTED=$(get-selected-essid-ap)
 179             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 180             echo "Running DHCP on ${INTERFACE} for ESSID \"${ESSID}\"."
 181             iwconfig ${INTERFACE} ap auto essid "${ESSID}"
 182             kill-dhcp
 183             echo
 184             dhclient ${INTERFACE}
 185             # if [[ $? == 0 ]]; then
 186                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 187             # fi
 188             ifconfig ${INTERFACE} mtu ${MTU}
 189             interface_was_up=1
 190             cont=0
 191             ;;
 192
 193         "return"|a) # Selects essid/ap + dhcp
 194             SELECTED=$(get-selected-essid-ap)
 195             ESSID=$(echo ${SELECTED} | cut -f 1 -d,)
 196             AP=$(echo ${SELECTED} | cut -f 2 -d,)
 197             echo "Running DHCP on ${INTERFACE} for ESSID \"${ESSID}\" and AP ${AP}."
 198             iwconfig ${INTERFACE} ap ${AP} essid "${ESSID}"
 199             kill-dhcp
 200             echo
 201             dhclient ${INTERFACE}
 202             # if [[ $? == 0 ]]; then
 203                 # iwconfig ${INTERFACE} > ~/.hotspot-ap
 204             # fi
 205             ifconfig ${INTERFACE} mtu ${MTU}
 206             interface_was_up=1
 207             cont=0
 208             ;;
 209
 210         k) # kill dhcp
 211             echo "Killing DHCP and bringing down ${INTERFACE}."
 212             kill-dhcp
 213             ifconfig ${INTERFACE} down
 214             cont=0
 215             ;;
 216
 217         r|s) # re-scanning the access points
 218             scan
 219             redisplay
 220             ;;
 221
 222         m) # Switching the mode to show the protected spots
 223             SHOW_CLOSED=$((1-SHOW_CLOSED))
 224             scan
 225             redisplay
 226             ;;
 227
 228         "down"|n)
 229             current_ap=$((current_ap+1))
 230             if [[ $current_ap -gt $number_of_aps ]]; then
 231                 current_ap=$number_of_aps
 232             fi
 233             redisplay
 234             ;;
 235
 236         "up"|p)
 237             current_ap=$((current_ap-1))
 238             if [[ $current_ap -lt 1 ]]; then
 239                 current_ap=1
 240             fi
 241             redisplay
 242             ;;
 243
 244         "esc-esc"|q)
 245             echo "  Quit."
 246             cont=0
 247             ;;
 248
 249         *)
 250             ;;
 251     esac
 252 }
 253
 254 ######################################################################
 255 ## The main
 256
 257 if [[ $1 == "-k" ]]; then
 258     echo "Killing DHCP and bringing down ${INTERFACE}."
 259     kill-dhcp
 260     ifconfig ${INTERFACE} down
 261     exit 1
 262 fi
 263
 264 trap cleanup-before-quit EXIT
 265
 266 stty_state=$(stty -g)
 267
 268 trap sigint-handler SIGHUP SIGINT SIGQUIT SIGABRT SIGTERM
 269
 270 stty -echo -icrnl -icanon -xcase min 1 time 0
 271
 272 echo ${VT_CURSOR_OFF}
 273
 274 current_ap=1
 275 cont=1
 276 current_keymap=default
 277
 278 interface_was_up=$(ifconfig | grep ${INTERFACE})
 279
 280 ifconfig ${INTERFACE} up
 281
 282 scan
 283
 284 redisplay
 285
 286 while [[ ${cont} == 1 ]]; do
 287
 288     CHAR=$(dd bs=1 count=1 2>/dev/null)
 289
 290     case ${current_keymap} in
 291         default) ##################################################
 292             case ${CHAR} in
 293
 294                 [a-z])
 295                     process-key ${CHAR}
 296                     ;;
 297
 298                 "\r")
 299                     process-key "return"
 300                     ;;
 301
 302                 "\ e")
 303                     process-key "down"
 304                     ;;
 305
 306                 "\10")
 307                     process-key "up"
 308                     ;;
 309
 310                 "\e") #$'\033'")
 311                     current_keymap=escape
 312                     ;;
 313
 314                 *)
 315                     ;;
 316             esac
 317             ;;
 318
 319         escape) ##################################################
 320             case ${CHAR} in
 321                 "$'\033'")
 322                     process-key "esc-esc"
 323                     ;;
 324                 "[")
 325                     current_keymap=cursor
 326                     ;;
 327                 *)
 328                     current_keymap=default
 329                     ;;
 330             esac
 331             ;;
 332
 333         cursor) ##################################################
 334
 335             current_keymap=default
 336
 337             case ${CHAR} in
 338                 A)
 339                     process-key "up"
 340                     ;;
 341                 B)
 342                     process-key "down"
 343                     ;;
 344                 *)
 345                     ;;
 346             esac
 347             ;;
 348
 349         *)
 350             echo "Unknown keymap. This is an internal and weird bug."
 351             cont=0
 352             ;;
 353     esac
 354
 355 done