uribeacon_scan

#!/bin/bash

# Copyright 2014 Google Inc. All rights reserved.
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# uribeacon_scan - scan for Bluetooth 4.0 UriBeacon advertisements
#
# Requirements:
#  apt-get install bluez-hcidump

sudo hcitool lescan --duplicates 1>/dev/null &
trap "sudo kill $!" EXIT
sudo hcidump --raw | awk '
BEGIN {
      line = ""
      Codes[0] = "http://www."
      Codes[1] = "https://www."
      Codes[2] = "http://"
      Codes[3] = "https://"
      Codes[4] = "tel:"
      Codes[5] = "mailto:"
      Codes[6] = "geo:"
      Codes[7] = ".com"
      Codes[8] = ".org"
      Codes[9] = ".edu"
}

function get_mac(bytes) {
  return (bytes[13] ":" bytes[12] ":" bytes[11] ":" bytes[10] ":" bytes[9] ":" bytes[8])
}

function get_uri(bytes) {
  uri = ""
  limit = service_data_limit(bytes)
  for (i = 28; i <= limit; i++) {
    code = strtonum("0x"bytes[i])
    if (code in Codes) {
       uri = uri Codes[code]
    } else {
       uri = uri sprintf("%c", code)
    }
  }
  return uri
}

function get_flags(bytes) {
  return bytes[26]
}

function get_tx_power(bytes) {
  return bytes[27]
}

# Returns the max index into the service data AD field
function service_data_limit(bytes) {
	 val = 22 + strtonum("0x"bytes[22])
	 return val
}

function has_service_data(bytes) {
  return (length(bytes) > 25 &&
  	 bytes[23] == "16" &&
	 bytes[24] == "D8" &&
	 bytes[25] == "FE")
}

function has_service_uuid(bytes) {
  return (length(bytes) > 21 &&
  	 bytes[18] == "03" &&
	 bytes[19] == "03" &&
	 bytes[20] == "D8" &&
         bytes[21] == "FE")
}

$1 == ">" {
  if (line != "") {
    split(line, bytes, " ")
    if (has_service_uuid(bytes) && has_service_data(bytes)) {
      print ""
      print "Mac:     " get_mac(bytes)
      print "Flags:   " get_flags(bytes)
      print "TxPower: " get_tx_power(bytes)
      print "Uri:     " get_uri(bytes)
      print "Raw:     " line
    } else {
#      print "Other: " line
    }
  }
  # Remove the ">" char at the start of line and restart
  $1 = ""
  line = $0
  next
}

/[0-9][0-9]/ {
  # concat each additional line starting with a number
  line = line $0
 }' -