From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 1D94223185D for ; Thu, 6 Nov 2025 04:17:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762402630; cv=none; b=puMdyO/V1tr8U1bCNsiMgAzMEKWR1KGnraThCypYa1CVZLRLPLJVkZcpdmQ4NA4c8OZQvHl7vJMYvj67KkqNbS3fvGoWcJSrU4QE52jfbHQ32eb2+FMa7oU6BuK3e4d3/agitx/CIbEp1aNUlLhvjoWbmkAutP377gUNIrTrOBw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762402630; c=relaxed/simple; bh=bWktklmOZkDwnVOH9HkFHc9GSbR+DbaHhG6ngBQSERE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gaSWrU26luU+ITab2mJd41jqoQhT3dEkhB2UPOkH52Hb7OEManLkySpdilEochwwZsp+wXXJhI/7z3gjnvMjCkZcLCQAyu4I/4OsNp58EGQFp5s6cduLl6gI+a5W9SZSKcsiyzI8UitHSLy0i6gG6pkUAOgscXoPVHB6rfLMdpI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=USmEGR4P; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="USmEGR4P" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1762402614; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=86xDxTdAU6WF+fO8WsDlbcAOxAJjdB5iyg5ImNIxrCg=; b=USmEGR4PUEkMQKSmpmgfCNWlfWyYejBACJkWO35dT/HD0qeO2PXyvjKDkq5Fn4edS4gKV8 j/HRlQ7KyhipoHgQfPMiMYrGg2hE/7jofloUMGaCq/WLTtJf79dVMPuxJ4gz+xcfnOsrBn TDLCTe8EhUQo+w4vxtXm7MkqIZKf5Ow= Date: Wed, 5 Nov 2025 20:16:45 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v4 2/3] net/smc: bpf: Introduce generic hook for handshake flow To: "D. Wythe" Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, pabeni@redhat.com, song@kernel.org, sdf@google.com, haoluo@google.com, yhs@fb.com, edumazet@google.com, john.fastabend@gmail.com, kpsingh@kernel.org, jolsa@kernel.org, mjambigi@linux.ibm.com, wenjia@linux.ibm.com, wintera@linux.ibm.com, dust.li@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, bpf@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, sidraya@linux.ibm.com, jaka@linux.ibm.com References: <20251103073124.43077-1-alibuda@linux.alibaba.com> <20251103073124.43077-3-alibuda@linux.alibaba.com> <4450b847-6b31-46f2-bc2d-a8b3197d15c7@linux.dev> <20251105070140.GA31761@j66a10360.sqa.eu95> <20251106023302.GA44223@j66a10360.sqa.eu95> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: <20251106023302.GA44223@j66a10360.sqa.eu95> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 11/5/25 6:33 PM, D. Wythe wrote: > On Wed, Nov 05, 2025 at 02:58:48PM -0800, Martin KaFai Lau wrote: >> >> >> On 11/4/25 11:01 PM, D. Wythe wrote: >>> On Tue, Nov 04, 2025 at 04:03:46PM -0800, Martin KaFai Lau wrote: >>>> >>>> >>>> On 11/2/25 11:31 PM, D. Wythe wrote: >>>>> +#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF) >>>>> +#define smc_call_hsbpf(init_val, sk, func, ...) ({ \ >>>>> + typeof(init_val) __ret = (init_val); \ >>>>> + struct smc_hs_ctrl *ctrl; \ >>>>> + rcu_read_lock(); \ >>>>> + ctrl = rcu_dereference(sock_net(sk)->smc.hs_ctrl); \ >>>> >>>> The smc_hs_ctrl (and its ops) is called from the netns, so the >>>> bpf_struct_ops is attached to a netns. Attaching bpf_struct_ops to a >>>> netns has not been done before. More on this later. >>>> >>>>> + if (ctrl && ctrl->func) \ >>>>> + __ret = ctrl->func(__VA_ARGS__); \ >>>>> + >>>>> + if (static_branch_unlikely(&tcp_have_smc) && tp->syn_smc) { >>>>> + tp->syn_smc = !!smc_call_hsbpf(1, sk, syn_option, tp); >>>> >>>> ... so just pass tp instead of passing both sk and tp? >>>> >>>> [ ... ] >>>> >>> >>> You're right, it is a bit redundant. However, if we merge the parameters, >>> every user of this macro will be forced to pass tp. In fact, we’re >>> already considering adding some callback functions that don’t take tp as >>> a parameter. >> >> If the struct_ops callback does not take tp, then don't pass it to the >> callback. I have a hard time to imagine why the bpf prog will not be >> interested in the tp/sk pointer though. >> >> or you meant the caller does not have tp? and where is the future caller? > > My initial concern was that certain ctrl->func callbacks might > eventually need to operate on an smc_sock rather than a tcp_sock. hmm...in that case, I think it first needs to understand where else the smc struct_ops is planned to be called in the future. I thought the smc struct_ops is something unique to the af_smc address family but I suspect the future ops addition may not be the case. Can you share some details on where the future callback will be? e.g. in smc_{connect, sendmsg, recvmsg...} that has the smc_sock?