57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
# SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
import array
|
|
import struct
|
|
import fcntl
|
|
import socket
|
|
|
|
from .utils import Util
|
|
|
|
ETHTOOL_GPERMADDR = 0x00000020
|
|
SIOCETHTOOL = 0x8946
|
|
MAX_ADDR_LEN = 32
|
|
IFNAMESIZ = 16
|
|
|
|
|
|
def get_perm_addr(ifname):
|
|
"""
|
|
Return the Permanent address value for the specified interface using the
|
|
ETHTOOL_GPERMADDR ioctl command.
|
|
|
|
Please for further documentation, see:
|
|
https://github.com/torvalds/linux/blob/master/include/uapi/linux/ethtool.h#L734
|
|
https://github.com/torvalds/linux/blob/master/include/uapi/linux/ethtool.h#L1388
|
|
https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/tree/ethtool.c#n4172
|
|
"""
|
|
try:
|
|
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
|
|
sockfd = sock.fileno()
|
|
ifname = ifname.encode("utf-8")
|
|
if len(ifname) > IFNAMESIZ:
|
|
return None
|
|
|
|
ecmd = array.array(
|
|
"B",
|
|
struct.pack(
|
|
"II%is" % MAX_ADDR_LEN,
|
|
ETHTOOL_GPERMADDR,
|
|
MAX_ADDR_LEN,
|
|
b"\x00" * MAX_ADDR_LEN,
|
|
),
|
|
)
|
|
ifreq = struct.pack("%isP" % IFNAMESIZ, ifname, ecmd.buffer_info()[0])
|
|
|
|
fcntl.ioctl(sockfd, SIOCETHTOOL, ifreq)
|
|
try:
|
|
res = ecmd.tobytes()
|
|
except AttributeError: # tobytes() is not available in python2
|
|
res = ecmd.tostring()
|
|
_, size, perm_addr = struct.unpack("II%is" % MAX_ADDR_LEN, res)
|
|
perm_addr = Util.mac_ntoa(perm_addr[:size])
|
|
except IOError:
|
|
perm_addr = None
|
|
finally:
|
|
sock.close()
|
|
|
|
return perm_addr
|