def genlmsg_user_data(gnlh, hdrlen):
return bytearray_ptr(genlmsg_user_hdr(gnlh), NLMSG_ALIGN(hdrlen))<EOL>
Return bytearray_ptr of the user data.

    https://github.com/thom311/libnl/blob/libnl3_2_25/lib/genl/genl.c#L259

    Calculates the bytearray_ptr of the user data based on the Generic Netlink message header.

    Positional arguments:
    gnlh -- Generic Netlink message header (genlmsghdr class instance).
    hdrlen -- length of user header (integer).

    Returns:
    bytearray_ptr of the user data.