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