#!/bin/sh

for F in $*
do
    echo
    echo '###################' $F '###################' 

    # Asking the unit for info_data.js gives a line that looks like
    # DATA="blahblah"

    curl -s -u admin:admin --connect-timeout 10 http://${F}/info_data.js |
    perl -e '
    sub charToSixBits {
        return index(".ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_", $_[0]);
    }
    
    # Get the DATA="blah" line, which must be exactly 551 bytes long

    if (read(STDIN,$X,1000) != 551) {
        exit 1;
    }
    $X=substr $X,6,-1;      # Leave the actual data
    
    # Convert string $X (base64) to $S (binary)

    $S="";
    while ($X) {
      $cc = (charToSixBits(substr($X,0,1)) << 18) +
            (charToSixBits(substr($X,1,1)) << 12) +
            (charToSixBits(substr($X,2,1)) << 6) +
            (charToSixBits(substr($X,3,1)));
      $S = $S . chr(($cc >> 16) & 255) . chr(($cc >> 8) & 255) . chr($cc & 255);
      $X=substr($X,4);
    }
    
    # Unpack the various fields from the first 72 bytes of the block

    ($SSID, $channel, $BSSID, $txrate, $quality, $MACbridged, $MAC, $IP, $firmware) = 
            unpack("x2 A32 c1 A6 c1 c1 H12 H12 N a11", $S);

    # Print them out...

    printf("%12s: %s\n",  "SSID", $SSID);
    printf("%12s: %s\n",  "channel", $channel);
    printf("%12s: %d (%s Mbit/s)\n",  "txrate", $txrate, ($txrate <= 1) ? "1" : ($txrate <= 3) ? "2" : ($txrate <= 7) ? "5.5" : "11");
    printf("%12s: %d\n",  "quality", int(0.5 + ((100 * $quality) / 92)));
    printf("%12s: %s\n",  "MAC bridged", $MACbridged);
    printf("%12s: %s\n",  "MAC", $MAC);
    printf("%12s: %d.%d.%d.%d\n",  "IP", 255 & ($IP >> 24), 255 & ($IP >> 16), 255 & ($IP >> 8), 255 & $IP, );
    printf("%12s: %d.%d.%d.%d%d%d.%d%d%d\n",  "firmware", 
            ord(substr($firmware,0,1)),
            ord(substr($firmware,1,1)),
            ord(substr($firmware,2,1)),
            ord(substr($firmware,3,1)),
            ord(substr($firmware,4,1)),
            ord(substr($firmware,5,1)),
            ord(substr($firmware,6,1)),
            ord(substr($firmware,7,1)),
            ord(substr($firmware,8,1)));
    printf("\n");
    $S=substr($S, 72);

    # There are up to 8 scans reported, each takes 42 bytes

    printf("SSID          MAC           channel strength\n");
    while ($S) {
        ($SSID, $MAC, $channel, $strength) = unpack("A32 H12 c1 c1", $S);
        # A nonzero MAC means that there was something found in this slot
        if ($MAC != "000000000000") {
            printf("%-12s  %-12s     %2d     %3d\n", $SSID, $MAC, $channel, $strength);
        }
        $S=substr($S, 42);
    }'
done