#

# Copyright (c) 2018-2019 Red Hat, Inc.

#

# This file is part of nmstate

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Lesser General Public License as published by

# the Free Software Foundation, either version 2.1 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Lesser General Public License for more details.

#

# You should have received a copy of the GNU Lesser General Public License

# along with this program. If not, see <https://www.gnu.org/licenses/>.

#

""" Minimal wrapper around the SIOCETHTOOL IOCTL to provide data that Network

Manager is not yet providing.

https://bugzilla.redhat.com/show_bug.cgi?id=1621188

"""

import array

import struct

import fcntl

import socket

ETHTOOL_GSET = 0x00000001  # Get settings

SIOCETHTOOL = 0x8946

def minimal_ethtool(interface):

    """

    Return dictionary with speed, duplex and auto-negotiation settings for the

    specified interface using the ETHTOOL_GSET command. The speed is returned n

    MBit/s, 0 means that the speed could not be determined. The duplex setting

    is 'unknown', 'full' or 'half. The auto-negotiation setting True or False

    or None if it could not be determined.

    Based on:

    https://github.com/rlisagor/pynetlinux/blob/master/pynetlinux/ifconfig.py

    https://elixir.bootlin.com/linux/v4.19-rc1/source/include/uapi/linux/ethtool.h

    :param interface str: Name of interface

    :returns dict: Dictionary with the keys speed, duplex, auto-negotiation

    """

    try:

        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        sockfd = sock.fileno()

        ecmd = array.array(

            "B", struct.pack("I39s", ETHTOOL_GSET, b"\x00" * 39)

        )

        interface = interface.encode("utf-8")

        ifreq = struct.pack("16sP", interface, ecmd.buffer_info()[0])

        fcntl.ioctl(sockfd, SIOCETHTOOL, ifreq)

        res = ecmd.tobytes()

        speed, duplex, auto = struct.unpack("12xHB3xB24x", res)

    except IOError:

        speed, duplex, auto = 65535, 255, 255

    finally:

        sock.close()

    if speed == 65535:

        speed = 0

    if duplex == 255:

        duplex = "unknown"

    else:

        duplex = "full" if bool(duplex) else "half"

    if auto == 255:

        auto = None

    else:

        auto = bool(auto)

    return {"speed": speed, "duplex": duplex, "auto-negotiation": auto}