From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C86D1474C9; Mon, 9 Dec 2024 16:26:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733761619; cv=none; b=F61IX+evcqCQw814Bcj29XioqUld11ThGDiywCIUKYzUuHGAtENAtllTgJihNimWcX3LWS55Xk4IfWLXgc7n5Ji6WAvryPobzkl2kLd6WOwX54dV2CWIZzoMAvmI0RCg508Eq08AhlZv7yEtjjG/qN3W3AfyEoLgqZ+e08YDvOQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733761619; c=relaxed/simple; bh=70s4BHZFldWeAL3yPeGci5plIEHzNmGXbTPLv9Fto+0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=lTvMwzpmJfTEWEyXwPTuBTvkicUj/MAMkU/K3U3kCcqCsxl4SrvbEdGD4Q+WgdYm0MVyq1ce86jI8e1OKYj3XuY/Vcj5OH6j39aI38z7U3ycVmArB/+N42s0W9aLl4R/QAnSB/4VcKjMSV7XySLr1CQsECKBHCEnukA+k1LvxTo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uN+xj6jh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uN+xj6jh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAECDC4CED1; Mon, 9 Dec 2024 16:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733761618; bh=70s4BHZFldWeAL3yPeGci5plIEHzNmGXbTPLv9Fto+0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uN+xj6jhKTV/GSloqEzcg/XJisdudFqqpka/VHNw8JxYmmpXLrBEy6ZOvSAQs6dVO PPdBz0y02mzU+bYYt/zib236PaSTb6L3otSB3cHiYH2spym5hr76FWa2LhBW/L7MDk eM8gWnuyua4x61D9yCY9j8ZI6alGLNburTP8tBdoofkrXHR85HLCDQ1BqYh5IrdvWC RIIxmcVW4LC3JrHzj8Q35EEf6/U01/XV9i5/1yykOA1LgL1FD+dl7clUBuUtgBboFq m61DJ+M6cDFmtMmXvzbp6YR95ln0QmSiDd5FMyMtNLn/zklu6tkpa78TP6iszs0dVn V2neqgtaztIYQ== Message-ID: <4b9ce06a-8ece-4951-b660-05ac1afd1a5f@kernel.org> Date: Mon, 9 Dec 2024 17:26:52 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net-next v12 11/22] ovpn: implement TCP transport Content-Language: en-GB To: Antonio Quartulli Cc: Simon Horman , netdev@vger.kernel.org, Paolo Abeni , Eric Dumazet , Jakub Kicinski , Donald Hunter , Shuah Khan , sd@queasysnail.net, ryazanov.s.a@gmail.com, Andrew Lunn , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20241202-b4-ovpn-v12-0-239ff733bf97@openvpn.net> <20241202-b4-ovpn-v12-11-239ff733bf97@openvpn.net> <784fddc4-336c-4674-8277-c7cebea6b94f@redhat.com> <2a1b614c-c52d-44c7-8cb8-c68a8864508d@openvpn.net> <8714deae-c1f7-42ff-9e76-fabd9ca5188b@openvpn.net> <17e7d4c6-4912-4d5e-8723-45a06a1ad529@openvpn.net> <813d75bf-1d7f-472b-967f-27ab8f9d4759@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit On 09/12/2024 15:08, Antonio Quartulli wrote: > On 09/12/2024 12:31, Matthieu Baerts wrote: >> On 09/12/2024 11:58, Antonio Quartulli wrote: >>> On 09/12/2024 11:46, Matthieu Baerts wrote: >>>> Hi Antonio, >>>> >>>> Thank you for working on this, and sharing your work here! >>>> >>>> On 05/12/2024 00:09, Antonio Quartulli wrote: >>>>> On 04/12/2024 23:52, Antonio Quartulli wrote: >>>>>> Paolo, >>>>>> >>>>>> On 04/12/2024 12:15, Antonio Quartulli wrote: >>>>>> [...] >>>>>>>>> +        mutex_lock(&tcp6_prot_mutex); >>>>>>>>> +        if (!ovpn_tcp6_prot.recvmsg) >>>>>>>>> +            ovpn_tcp_build_protos(&ovpn_tcp6_prot, >>>>>>>>> &ovpn_tcp6_ops, >>>>>>>>> +                          sock->sk->sk_prot, >>>>>>>>> +                          sock->sk->sk_socket->ops); >>>>>>>>> +        mutex_unlock(&tcp6_prot_mutex); >>>>>>>> >>>>>>>> This looks like an hack to avoid a build dependency on IPV6, I >>>>>>>> think >>>>>>>> the >>>>>>>> explicit >>>>>>> >>>>>>> I happily copied this approach from >>>>>>> espintcp.c:espintcp_init_sk() :-D >>>>>>> >>>>>>>> >>>>>>>> #if IS_ENABLED(CONFIG_IPV6) >>>>>>>> >>>>>>>> at init time should be preferable >>>>>> >>>>>> To get this done at init time I need inet6_stream_ops to be >>>>>> accessible, but it seems there is no EXPORT_SYMBOL() for this object. >>>>>> >>>>>> However, I see that mptcp/protocol.c is happily accessing it. >>>>>> Any clue how this is possible? >>>>> >>>>> I answer myself: mptcp is not tristate and it can only be compiled as >>>>> built-in. >>>> >>>> Indeed, that's why. >>>> >>>> Talking about MPTCP, by chance, do you plan to support it later on? :) >>> >>> Hi Matthieu, >>> >>> It is not on our current roadmap (TCP doesn't get much love in the VPN >>> world), but I agree it could be an interesting option to explore! >> >> I understand, it makes sense not to recommend using TCP for the >> transport layer for tunnelling solutions. >> >>> I have to admit that I haven't played much with MPTCP myself yet, but I >>> am more than happy to talk about potential advantages for the ovpn use >>> case. >> >> Some people told me they were interested in using OpenVPN with MPTCP to >> use multiple (low-capacity) network links at the same time. I think >> intercepting and proxying TCP traffic would always be the best in terms >> of performances, but using OpenVPN with MPTCP seems to be enough for >> some, especially when they want to "improve" some type of UDP traffic >> that cannot be intercepted: QUIC, VPN, etc. >> >> I don't have numbers to share, but I can understand this feature can >> help in some cases. > > Yeah, some people may definitely benefit from this feature. > I'll have a look at MPTCP once ovpn is merged. Thank you :) Don't hesitate to email the ML, or open an issue on the GitHub repo if needed! (More details: https://www.mptcp.dev/#communication) >> (This reminds me this: https://github.com/OpenVPN/ovpn-dco/issues/60) >> (and this: https://github.com/arinc9/openvpn/pull/1) > > Right, this definitely shows some interest and it means we should easily > find people willing to test :-) Indeed! Cheers, Matt -- Sponsored by the NGI0 Core fund.