"""Custom backend for FreeBSD."""
import os
import socket
import struct
import ctypes
libc = ctypes.cdll.LoadLibrary('libc.so.7')
NG_HCI_EVENT_MASK_LE = 0x2000000000000000
SOL_HCI_RAW = 0x0802
SOL_HCI_RAW_FILTER = 1
class SockaddrHci(ctypes.Structure):
"""Structure representing a hci socket address."""
_fields_ = [
('hci_len', ctypes.c_char),
('hci_family', ctypes.c_char),
('hci_node', ctypes.c_char * 32),
]
class HciRawFilter(ctypes.Structure):
"""Structure specifying filter masks."""
_fields_ = [
('packet_mask', ctypes.c_uint32),
('event_mask', ctypes.c_uint64),
]
def open_dev(bt_device_id):
"""Open hci device socket."""
# pylint: disable=no-member
sock = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_RAW, socket.BTPROTO_HCI)
# Unlike Linux, FreeBSD has separate numbering depending on hardware
# (ubt - USB bluetooth - is the most common, so convert numbers to that)
if not isinstance(bt_device_id, str):
bt_device_id = 'ubt{}hci'.format(bt_device_id)
# Python's BTPROTO_HCI address parsing is busted: https://bugs.python.org/issue41130
adr = SockaddrHci(ctypes.sizeof(SockaddrHci), socket.AF_BLUETOOTH, bt_device_id.ljust(32, '\0').encode('utf-8'))
if libc.bind(sock.fileno(), ctypes.pointer(adr), ctypes.sizeof(SockaddrHci)) != 0:
raise ConnectionError(ctypes.get_errno(), os.strerror(ctypes.get_errno()))
if libc.connect(sock.fileno(), ctypes.pointer(adr), ctypes.sizeof(SockaddrHci)) != 0:
raise ConnectionError(ctypes.get_errno(), os.strerror(ctypes.get_errno()))
# pylint: enable=no-member
fltr = HciRawFilter(0, NG_HCI_EVENT_MASK_LE)
if libc.setsockopt(sock.fileno(),
SOL_HCI_RAW, SOL_HCI_RAW_FILTER,
ctypes.pointer(fltr), ctypes.sizeof(HciRawFilter)) != 0:
raise ConnectionError(ctypes.get_errno(), os.strerror(ctypes.get_errno()))
return sock
def send_cmd(sock, group_field, command_field, data):
"""Send hci command to device."""
opcode = (((group_field & 0x3f) << 10) | (command_field & 0x3ff))
sock.send(struct.pack('<BHB', 1, opcode, len(data)) + data)
