blescan.py

# BLE iBeaconScanner based on https://github.com/adamf/BLE/blob/master/ble-scanner.py
# JCS 06/07/14

DEBUG = False
# BLE scanner based on https://github.com/adamf/BLE/blob/master/ble-scanner.py
# BLE scanner, based on https://code.google.com/p/pybluez/source/browse/trunk/examples/advanced/inquiry-with-rssi.py

# https://github.com/pauloborges/bluez/blob/master/tools/hcitool.c for lescan
# https://kernel.googlesource.com/pub/scm/bluetooth/bluez/+/5.6/lib/hci.h for opcodes
# https://github.com/pauloborges/bluez/blob/master/lib/hci.c#L2782 for functions used by lescan

# performs a simple device inquiry, and returns a list of ble advertizements
# discovered device

# NOTE: Python's struct.pack() will add padding bytes unless you make the endianness explicit. Little endian
# should be used for BLE. Always start a struct.pack() format string with "<"

import os
import sys
import struct
import bluetooth._bluetooth as bluez

LE_META_EVENT = 0x3e
LE_PUBLIC_ADDRESS = 0x00
LE_RANDOM_ADDRESS = 0x01
LE_SET_SCAN_PARAMETERS_CP_SIZE = 7
OGF_LE_CTL = 0x08
OCF_LE_SET_SCAN_PARAMETERS = 0x000B
OCF_LE_SET_SCAN_ENABLE = 0x000C
OCF_LE_CREATE_CONN = 0x000D

LE_ROLE_MASTER = 0x00
LE_ROLE_SLAVE = 0x01

# these are actually subevents of LE_META_EVENT
EVT_LE_CONN_COMPLETE = 0x01
EVT_LE_ADVERTISING_REPORT = 0x02
EVT_LE_CONN_UPDATE_COMPLETE = 0x03
EVT_LE_READ_REMOTE_USED_FEATURES_COMPLETE = 0x04

# Advertisment event types
ADV_IND = 0x00
ADV_DIRECT_IND = 0x01
ADV_SCAN_IND = 0x02
ADV_NONCONN_IND = 0x03
ADV_SCAN_RSP = 0x04


def returnnumberpacket(pkt):
    myInteger = 0
    multiple = 256
    for c in pkt:
        myInteger += struct.unpack("B", c)[0] * multiple
        multiple = 1
    return myInteger


def returnstringpacket(pkt):
    myString = ""
    for c in pkt:
        myString += "%02x" % struct.unpack("B", c)[0]
    return myString


def printpacket(pkt):
    for c in pkt:
        sys.stdout.write("%02x " % struct.unpack("B", c)[0])


def get_packed_bdaddr(bdaddr_string):
    packable_addr = []
    addr = bdaddr_string.split(':')
    addr.reverse()
    for b in addr:
        packable_addr.append(int(b, 16))
    return struct.pack("<BBBBBB", *packable_addr)


def packed_bdaddr_to_string(bdaddr_packed):
    return ':'.join('%02x' % i for i in struct.unpack("<BBBBBB", bdaddr_packed[::-1]))


def hci_enable_le_scan(sock):
    hci_toggle_le_scan(sock, 0x01)


def hci_disable_le_scan(sock):
    hci_toggle_le_scan(sock, 0x00)


def hci_toggle_le_scan(sock, enable):
    # hci_le_set_scan_enable(dd, 0x01, filter_dup, 1000);
    # memset(&scan_cp, 0, sizeof(scan_cp));
 # uint8_t         enable;
 #       uint8_t         filter_dup;
    #        scan_cp.enable = enable;
    #        scan_cp.filter_dup = filter_dup;
    #
    #        memset(&rq, 0, sizeof(rq));
    #        rq.ogf = OGF_LE_CTL;
    #        rq.ocf = OCF_LE_SET_SCAN_ENABLE;
    #        rq.cparam = &scan_cp;
    #        rq.clen = LE_SET_SCAN_ENABLE_CP_SIZE;
    #        rq.rparam = &status;
    #        rq.rlen = 1;

    #        if (hci_send_req(dd, &rq, to) < 0)
    #                return -1;
    cmd_pkt = struct.pack("<BB", enable, 0x00)
    bluez.hci_send_cmd(sock, OGF_LE_CTL, OCF_LE_SET_SCAN_ENABLE, cmd_pkt)


def hci_le_set_scan_parameters(sock):
    old_filter = sock.getsockopt(bluez.SOL_HCI, bluez.HCI_FILTER, 14)

    SCAN_RANDOM = 0x01
    OWN_TYPE = SCAN_RANDOM
    SCAN_TYPE = 0x01


def parse_events(sock, loop_count=100):
    old_filter = sock.getsockopt(bluez.SOL_HCI, bluez.HCI_FILTER, 14)

    # perform a device inquiry on bluetooth device #0
    # The inquiry should last 8 * 1.28 = 10.24 seconds
    # before the inquiry is performed, bluez should flush its cache of
    # previously discovered devices
    flt = bluez.hci_filter_new()
    bluez.hci_filter_all_events(flt)
    bluez.hci_filter_set_ptype(flt, bluez.HCI_EVENT_PKT)
    sock.setsockopt(bluez.SOL_HCI, bluez.HCI_FILTER, flt)
    done = False
    results = []
    myFullList = []
    for i in range(0, loop_count):
        pkt = sock.recv(255)
        ptype, event, plen = struct.unpack("BBB", pkt[:3])
        # print "--------------"
        if event == bluez.EVT_INQUIRY_RESULT_WITH_RSSI:
            i = 0
        elif event == bluez.EVT_NUM_COMP_PKTS:
            i = 0
        elif event == bluez.EVT_DISCONN_COMPLETE:
            i = 0
        elif event == LE_META_EVENT:
            subevent, = struct.unpack("B", pkt[3])
            pkt = pkt[4:]
            if subevent == EVT_LE_CONN_COMPLETE:
                le_handle_connection_complete(pkt)
            elif subevent == EVT_LE_ADVERTISING_REPORT:
                # print "advertising report"
                num_reports = struct.unpack("B", pkt[0])[0]
                report_pkt_offset = 0
                for i in range(0, num_reports):

                    # if (DEBUG == True):
                        # print "-------------"
                    #         	#print "\tfullpacket: ", printpacket(pkt)
                    # 	print "\tUDID: ", printpacket(pkt[report_pkt_offset -22: report_pkt_offset - 6])
                    # 	print "\tMAJOR: ", printpacket(pkt[report_pkt_offset -6: report_pkt_offset - 4])
                    # 	print "\tMINOR: ", printpacket(pkt[report_pkt_offset -4: report_pkt_offset - 2])
                    #         	print "\tMAC address: ", packed_bdaddr_to_string(pkt[report_pkt_offset + 3:report_pkt_offset + 9])
                    # 	# commented out - don't know what this byte is.  It's NOT TXPower
                    #         	txpower, = struct.unpack("b", pkt[report_pkt_offset -2])
                    #         	print "\t(Unknown):", txpower

                    #         	rssi, = struct.unpack("b", pkt[report_pkt_offset -1])
                    #         	print "\tRSSI:", rssi
                    # build the return string
                    beacon = {
                        'mac_addr': packed_bdaddr_to_string(pkt[report_pkt_offset + 3:report_pkt_offset + 9]),
                        'uuid': returnstringpacket(pkt[report_pkt_offset - 22: report_pkt_offset - 6]),
                        'major': "%i" % returnnumberpacket(pkt[report_pkt_offset - 6: report_pkt_offset - 4]),
                        'minor': "%i" % returnnumberpacket(pkt[report_pkt_offset - 4: report_pkt_offset - 2]),
                        'unknown': "%i" % struct.unpack("b", pkt[report_pkt_offset - 2]),
                        'rssi': "%i" % struct.unpack("b", pkt[report_pkt_offset - 1])
                    }
                    # print "\tAdstring=", Adstring
                    myFullList.append(beacon)
                done = True
    sock.setsockopt(bluez.SOL_HCI, bluez.HCI_FILTER, old_filter)
    return myFullList