Discover Bluetooth devices nearby using, guess what, fiddle :)

bluetooth_scan.rb

#!/usr/bin/env ruby

require 'fiddle/import'
require 'fiddle/types'

LIBBT = '/usr/lib/libbluetooth.so.3'
LIBC  = '/usr/lib/libc.so.6'

module Bluetooth
  extend Fiddle::Importer
  dlload LIBBT, LIBC
  
  typealias "uint8_t", "unsigned char"
  typealias "uint16_t", "unsigned short"
  
  #bdaddr = struct [
  #  "uint8_t b[6]"
  #]

  InquiryInfo = struct [
    "uint8_t b[6]",
    "uint8_t pscan_rep_mode",
    "uint8_t pscan_period_mode",
    "uint8_t pscan_mode",
    "uint8_t dev_class[3]",
    "uint16_t clock_offset"
  ]
  
  extern "void *memset(void *str, int c, size_t n)"

  extern "int hci_get_route(bdaddr_t *bdaddr)"
  extern "int hci_open_dev(int dev_id)"
  extern "int ba2str(const bdaddr_t *ba, char *str)"
  extern "int hci_inquiry(int dev_id, int len, int max_rsp, const uint8_t *lap, inquiry_info **ii, long flags)"
  extern "int hci_read_remote_name(int sock, const bdaddr_t *ba, int len, char *name, int timeout)"
end

ii = Bluetooth::InquiryInfo.malloc
max_rsp, len, flags = 0xff, 0x8, 0x1
addr = Fiddle::Pointer.malloc(0x13)
name = Fiddle::Pointer.malloc(0xf8)

puts "Scanning..."

dev_id = Bluetooth.hci_get_route(Fiddle::NULL)
sock = Bluetooth.hci_open_dev(dev_id)
abort("error opening socket.") if [dev_id, sock].any? { |n| n < 0 }

num_rsp = Bluetooth.hci_inquiry(dev_id, len, max_rsp, Fiddle::NULL, ii, flags)
abort("hci inquiry failed.") if num_rsp < 0

puts "device(s) found: #{num_rsp}"

num_rsp.times.with_index(1) do |_, i|
  Bluetooth.ba2str(ii.to_ptr.ptr, addr)
  Bluetooth.memset(name, 0, name.size)
  if Bluetooth.hci_read_remote_name(sock, ii.to_ptr.ptr, name.size, name, 0) < 0
    name[0, name.size] = "[unknown]"
  end
  p "[%d] %s -> %s" % [i, addr, name]
end

##TODO FIXME