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([2a01:e0a:410:bb00:e0fd:c68f:ea32:2084]) by smtp.gmail.com with ESMTPSA id p3sm1152093wrn.47.2021.09.28.23.19.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Sep 2021 23:19:06 -0700 (PDT) Reply-To: nicolas.dichtel@6wind.com Subject: Re: [PATCH net-next v6] net: openvswitch: IPv6: Add IPv6 extension header support To: Jakub Kicinski , Toms Atteka Cc: netdev@vger.kernel.org, pshelar@ovn.org, davem@davemloft.net, dev@openvswitch.org, linux-kernel@vger.kernel.org References: <20210928194727.1635106-1-cpp.code.lv@gmail.com> <20210928174853.06fe8e66@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: Nicolas Dichtel Organization: 6WIND Message-ID: Date: Wed, 29 Sep 2021 08:19:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210928174853.06fe8e66@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 29/09/2021 à 02:48, Jakub Kicinski a écrit : > On Tue, 28 Sep 2021 12:47:27 -0700 Toms Atteka wrote: >> diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h >> index a87b44cd5590..dc6eb5f6399f 100644 >> --- a/include/uapi/linux/openvswitch.h >> +++ b/include/uapi/linux/openvswitch.h >> @@ -346,6 +346,13 @@ enum ovs_key_attr { >> #ifdef __KERNEL__ >> OVS_KEY_ATTR_TUNNEL_INFO, /* struct ip_tunnel_info */ >> #endif >> + >> +#ifndef __KERNEL__ > > #else > >> + PADDING, /* Padding so kernel and non kernel field count would match */ > > The name PADDING seems rather risky, collisions will be likely. > OVS_KEY_ATTR_PADDING maybe? > > But maybe we don't need to define this special value and bake it into > the uAPI, why can't we add something like this to the kernel header > (i.e. include/linux/openvswitch.h): > > /* Insert a kernel only KEY_ATTR */ > #define OVS_KEY_ATTR_TUNNEL_INFO __OVS_KEY_ATTR_MAX > #undef OVS_KEY_ATTR_MAX > #define OVS_KEY_ATTR_MAX __OVS_KEY_ATTR_MAX Following the other thread [1], this will break if a new app runs over an old kernel. Why not simply expose this attribute to userspace and throw an error if a userspace app uses it? [1] https://lore.kernel.org/lkml/CAASuNyUWoZ1wToEUYbdehux=yVnWQ=suKDyRkQfRD-72DOLziw@mail.gmail.com/ > >> +#endif