Experimenting with Bluetooth LE HCI commands in Python

hci_ble_test.py

import socket
import fcntl
import struct
import array

# ---------------------------------------------------

# HCI Constants  (https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/lib/hci.h)

# HCI ioctl Commands:
HCIDEVUP   = 0x400448c9 # 201
HCIDEVDOWN = 0x400448ca # 202
HCIGETDEVINFO = 0x7ffbb72d #_IOR(ord('H'), 211, 4)
HCISETSCAN = 0x400448dd #221

# hex values take from: import bluetooth._bluetooth as bluez, installed by: sudo apt-get install python-bluetooth



# HCI Parameters
SCAN_DISABLED = 0x00
SCAN_INQUIRY = 0x01
SCAN_PAGE = 0x02


# C HCI examples:  https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/tools/hciconfig.c

# Python struct data format specifiers (see: https://docs.python.org/3.0/library/struct.html)

# H	unsigned short	integer
# I	unsigned int	integer 


# ---------------------------------------------------

dev_id = 0

sock = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_RAW, socket.BTPROTO_HCI)
sock.bind((dev_id,))

# Get device info

#zero_filled = [0 for _ in range(256)]
#buffer = struct.pack('I%sb' % len(zero_filled), dev_id, *zero_filled)

buffer = struct.pack("HbBIBBIIIHHHH10I", dev_id, *((0,) * 22))
fcntl.ioctl(sock.fileno(), HCIGETDEVINFO, buffer)

# simple hex dump:
print( [hex(ord(c)) for c in buffer])

#  HCI Up
buffer = struct.pack("I", dev_id)
fcntl.ioctl(sock.fileno(), HCIDEVUP, buffer)


#  Set Scan
buffer = struct.pack("HI", dev_id, SCAN_INQUIRY)
fcntl.ioctl(sock.fileno(), HCISETSCAN, buffer)

#  HCI Down
buffer = struct.pack("I", dev_id)
fcntl.ioctl(sock.fileno(), HCIDEVDOWN, buffer)

sock.close()



# ---------------------------------------------------
# ---------------------------------------------------
# Notes:

# HCI Data structures for IOCTL buffers (subset, see hci.h):

"""
struct hci_dev_req {
	uint16_t dev_id;
	uint32_t dev_opt;
};

struct hci_dev_list_req {
	uint16_t dev_num;
	struct hci_dev_req dev_req[0];	/* hci_dev_req structures */
};

struct hci_dev_info {
	uint16_t dev_id;
	char     name[8];

	bdaddr_t bdaddr;

	uint32_t flags;
	uint8_t  type;

	uint8_t  features[8];

	uint32_t pkt_type;
	uint32_t link_policy;
	uint32_t link_mode;

	uint16_t acl_mtu;
	uint16_t acl_pkts;
	uint16_t sco_mtu;
	uint16_t sco_pkts;

	struct   hci_dev_stats stat;
};

"""