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Date:   Fri, 19 May 2023 08:15:26 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Breno Leitao <leitao@debian.org>
Cc:     axboe@kernel.dk, davem@davemloft.net, edumazet@google.com,
        pabeni@redhat.com, willemdebruijn.kernel@gmail.com,
        courmisch@gmail.com, nhorman@tuxdriver.com, asml.silence@gmail.com,
        alex.aring@gmail.com, dccp@vger.kernel.org, mptcp@lists.linux.dev,
        linux-kernel@vger.kernel.org, matthieu.baerts@tessares.net,
        marcelo.leitner@gmail.com, linux-wpan@vger.kernel.org,
        linux-sctp@vger.kernel.org, leit@fb.com, David.Laight@ACULAB.COM,
        dsahern@kernel.org
Subject: Re: [PATCH 0/1] net: ioctl: Use kernel buffer on proto ioctl
 callbacks
Message-ID: <20230519081526.59411533@kernel.org>
In-Reply-To: <20230519135821.922326-1-leitao@debian.org>
References: <20230519135821.922326-1-leitao@debian.org>
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On Fri, 19 May 2023 06:58:20 -0700 Breno Leitao wrote:
> With the implementation of network ioctl on io_uring[1], Willem
> suggested[2] that the "struct proto" ioctls functions should be reused,
> instead of duplicating the code.
> For that, the ioctl callbacks need to be more flexible, and avoid
> operating on userspace buffers (doing get/put_user()) directly on the
> callbacks. This patch adds this flexibility, so, the io_uring plumbing
> becomes more clean, avoiding duplicating code. This may also benefit
> BPF.
> 
> For that, a wrapper is created, which will copy from/to userspace, and
> the ioctl callback will rely on the wrapper to do userspace memory
> copies.
> 
> I've tested this patch in three different ways:
> 1) Created a simple testcase for TCP/UDP [3]
> 2) Run relevant LTP tests, such as: sockioctl, setsockopt, bind, sendto,
> 				    fanout, ns-udpsender, etc
> 3) Run basics network selftests
> 
> PS: There are some `strcmp()` in the `sock_skprot_ioctl()`, that I was
> not able to find a better way to deal with it. Any feedback is
> appreciated.

Why not CC netdev@ on this?