From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Subject: Re: [PATCH net-next v11 1/4] net netlink: Add new type NLA_BITFIELD_32 Date: Tue, 25 Jul 2017 07:15:52 -0400 Message-ID: References: <1500860146-26970-1-git-send-email-jhs@emojatatu.com> <1500860146-26970-2-git-send-email-jhs@emojatatu.com> <20170724111806.GB1868@nanopsycho> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, xiyou.wangcong@gmail.com, dsahern@gmail.com, eric.dumazet@gmail.com, mrv@mojatatu.com, simon.horman@netronome.com, alex.aring@gmail.com To: Jiri Pirko Return-path: Received: from mail-it0-f67.google.com ([209.85.214.67]:33008 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751540AbdGYLPy (ORCPT ); Tue, 25 Jul 2017 07:15:54 -0400 Received: by mail-it0-f67.google.com with SMTP id t6so9357114itb.0 for ; Tue, 25 Jul 2017 04:15:54 -0700 (PDT) In-Reply-To: <20170724111806.GB1868@nanopsycho> Content-Language: en-GB Sender: netdev-owner@vger.kernel.org List-ID: On 17-07-24 07:18 AM, Jiri Pirko wrote: > Mon, Jul 24, 2017 at 03:35:43AM CEST, jhs@mojatatu.com wrote: >> From: Jamal Hadi Salim >> >> Generic bitflags attribute content sent to the kernel by user. >> With this type the user can either set or unset a flag in the >> kernel. >> >> The nla_value is a bitmap that defines the values being set >> The nla_selector is a bitmask that defines which value is legit. >> >> A check is made to ensure the rules that a kernel subsystem always >> conforms to bitflags the kernel already knows about. i.e >> if the user tries to set a bit flag that is not understood then >> the _it will be rejected_. >> >> In the most basic form, the user specifies the attribute policy as: >> [ATTR_GOO] = { .type = NLA_BITFIELD_32, .validation_data = &myvalidflags }, >> >> where myvalidflags is the bit mask of the flags the kernel understands. >> >> If the user _does not_ provide myvalidflags then the attribute will >> also be rejected. >> >> Examples: >> nla_value = 0x0, and nla_selector = 0x1 >> implies we are selecting bit 1 and we want to set its value to 0. >> >> nla_value = 0x2, and nla_selector = 0x2 >> implies we are selecting bit 2 and we want to set its value to 1. > > Oh, 2 more things: > > [...] > ;-> ok will do that next opportunity (probably at 30K feet). cheers, jamal