From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 C286B15B108 for ; Sun, 29 Sep 2024 11:56:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727611017; cv=none; b=SOr2wxZW9R5dSMbxnLrprNyE6CvcAMXB6cwdAtsHRRncemclJxFo/uvgpW+fHQbCIfC1obnkb+x7lMDiVJgZb5zOuRqPNrzS/HJjWd59anI3NTyJkkSKfIL1mLcpZMEfWVWHjQT/4H4/868wpkcPii9NMZ65PGxyDmkjW4s2zTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727611017; c=relaxed/simple; bh=kRdlNh2IHMBzOlcxstBQXWNI19MwftyElilV8HkvdK4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ddYLiv5epJCvZXjk1cBsr4PKHWCa5mUibKQKjUM5vf/cmq7S+jdAxqIhdZ1nPr+EfQdFhk8cc0X54dSexJWtzLOWJNRMVYlxTTCtAz49IBFpbAbqdUhat0TtjymB05B8vdgus8qrTW/Shkcah0eYs+VtNt4KvMviEMWxdbzJZS8= 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=c16J43vL; arc=none smtp.client-ip=91.218.175.182 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="c16J43vL" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1727611011; 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=hAC//q1Q0snEPQ/btU6qHTHCF/zamSYZtJr8ip76b+8=; b=c16J43vLB2hZPHz6tqz1HC9iB1xmdlprrXdGrQVKOfjC40iLWd8pDmUjeHHwgem1CKxzGL Ng5nZZUJo8UqQRfBFImIqFuZFgu2gq6gdbZEYpu50omzXoS8Kf7yg0al9ZZIr83bb6Am1r Z2sy3Fygp6gN4K2Tke2melQjUDtFCXU= Date: Sun, 29 Sep 2024 19:56:17 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [RFC PATCH net-next v2] net/smc: Introduce a hook to modify syn_smc at runtime To: "D. Wythe" , kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com, wintera@linux.ibm.com, guwen@linux.alibaba.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org, tonylu@linux.alibaba.com, pabeni@redhat.com, edumazet@google.com, bpf@vger.kernel.org References: <1727408549-106551-1-git-send-email-alibuda@linux.alibaba.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <1727408549-106551-1-git-send-email-alibuda@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2024/9/27 11:42, D. Wythe 写道: > From: "D. Wythe" > > The introduction of IPPROTO_SMC enables eBPF programs to determine > whether to use SMC based on the context of socket creation, such as > network namespaces, PID and comm name, etc. > > As a subsequent enhancement, this patch introduces a new hook for eBPF > programs that allows decisions on whether to use SMC or not at runtime, > including but not limited to local/remote IP address or ports. In > simpler words, this feature allows modifications to syn_smc through eBPF > programs before the TCP three-way handshake got established. > > Thanks to kfunc for making it easier for us to implement this feature in > SMC. > > Signed-off-by: D. Wythe > > --- > v1 -> v2: > 1. Fix wrong use of ireq->smc_ok, should be rx_opt->smc_ok. > 2. Fix compile error when CONFIG_IPV6 or CONFIG_BPF_SYSCALL was not set. > > --- > include/linux/tcp.h | 4 ++- > net/ipv4/tcp_input.c | 4 +-- > net/smc/af_smc.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++------ > 3 files changed, 72 insertions(+), 11 deletions(-) > > diff --git a/include/linux/tcp.h b/include/linux/tcp.h > index 6a5e08b..d028d76 100644 > --- a/include/linux/tcp.h > +++ b/include/linux/tcp.h > @@ -478,7 +478,9 @@ struct tcp_sock { > #endif > #if IS_ENABLED(CONFIG_SMC) > bool syn_smc; /* SYN includes SMC */ > - bool (*smc_hs_congested)(const struct sock *sk); > + void (*smc_openreq_init)(struct request_sock *req, > + const struct tcp_options_received *rx_opt, > + struct sk_buff *skb, const struct sock *sk); > #endif > > #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index 9f314df..99f34f5 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -7036,8 +7036,8 @@ static void tcp_openreq_init(struct request_sock *req, > ireq->ir_num = ntohs(tcp_hdr(skb)->dest); > ireq->ir_mark = inet_request_mark(sk, skb); > #if IS_ENABLED(CONFIG_SMC) > - ireq->smc_ok = rx_opt->smc_ok && !(tcp_sk(sk)->smc_hs_congested && > - tcp_sk(sk)->smc_hs_congested(sk)); > + if (rx_opt->smc_ok && tcp_sk(sk)->smc_openreq_init) > + tcp_sk(sk)->smc_openreq_init(req, rx_opt, skb, sk); > #endif > } > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index 0316217..fdac7e2b 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -70,6 +70,15 @@ > static void smc_tcp_listen_work(struct work_struct *); > static void smc_connect_work(struct work_struct *); > > +__bpf_hook_start(); > + > +__weak noinline int select_syn_smc(const struct sock *sk, struct sockaddr *peer) > +{ > + return 1; > +} > + > +__bpf_hook_end(); > + > int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb) > { > struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb); > @@ -156,19 +165,43 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk, > return NULL; > } > > -static bool smc_hs_congested(const struct sock *sk) > +static void smc_openreq_init(struct request_sock *req, > + const struct tcp_options_received *rx_opt, > + struct sk_buff *skb, const struct sock *sk) > { > + struct inet_request_sock *ireq = inet_rsk(req); > + struct sockaddr_storage rmt_sockaddr = {0}; A trivial problem. The following should be better? struct sockaddr_storage rmt_sockaddr = {}; I think, we have discussed this problem in RDMA maillist for several times. Zhu Yanjun > const struct smc_sock *smc; > > smc = smc_clcsock_user_data(sk); > > if (!smc) > - return true; > + return; > > - if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq)) > - return true; > + if (smc->limit_smc_hs && workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq)) > + goto out_no_smc; > > - return false; > + rmt_sockaddr.ss_family = sk->sk_family; > + > + if (rmt_sockaddr.ss_family == AF_INET) { > + struct sockaddr_in *rmt4_sockaddr = (struct sockaddr_in *)&rmt_sockaddr; > + > + rmt4_sockaddr->sin_addr.s_addr = ireq->ir_rmt_addr; > + rmt4_sockaddr->sin_port = ireq->ir_rmt_port; > +#if IS_ENABLED(CONFIG_IPV6) > + } else { > + struct sockaddr_in6 *rmt6_sockaddr = (struct sockaddr_in6 *)&rmt_sockaddr; > + > + rmt6_sockaddr->sin6_addr = ireq->ir_v6_rmt_addr; > + rmt6_sockaddr->sin6_port = ireq->ir_rmt_port; > +#endif /* CONFIG_IPV6 */ > + } > + > + ireq->smc_ok = select_syn_smc(sk, (struct sockaddr *)&rmt_sockaddr); > + return; > +out_no_smc: > + ireq->smc_ok = 0; > + return; > } > > struct smc_hashinfo smc_v4_hashinfo = { > @@ -1671,7 +1704,7 @@ int smc_connect(struct socket *sock, struct sockaddr *addr, > } > > smc_copy_sock_settings_to_clc(smc); > - tcp_sk(smc->clcsock->sk)->syn_smc = 1; > + tcp_sk(smc->clcsock->sk)->syn_smc = select_syn_smc(sk, addr); > if (smc->connect_nonblock) { > rc = -EALREADY; > goto out; > @@ -2650,8 +2683,7 @@ int smc_listen(struct socket *sock, int backlog) > > inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops; > > - if (smc->limit_smc_hs) > - tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested; > + tcp_sk(smc->clcsock->sk)->smc_openreq_init = smc_openreq_init; > > rc = kernel_listen(smc->clcsock, backlog); > if (rc) { > @@ -3475,6 +3507,24 @@ static void __net_exit smc_net_stat_exit(struct net *net) > .exit = smc_net_stat_exit, > }; > > +#if IS_ENABLED(CONFIG_BPF_SYSCALL) > +BTF_SET8_START(bpf_smc_fmodret_ids) > +BTF_ID_FLAGS(func, select_syn_smc) > +BTF_SET8_END(bpf_smc_fmodret_ids) > + > +static const struct btf_kfunc_id_set bpf_smc_fmodret_set = { > + .owner = THIS_MODULE, > + .set = &bpf_smc_fmodret_ids, > +}; > + > +static int bpf_smc_kfunc_init(void) > +{ > + return register_btf_fmodret_id_set(&bpf_smc_fmodret_set); > +} > +#else > +static inline int bpf_smc_kfunc_init(void) { return 0; } > +#endif /* CONFIG_BPF_SYSCALL */ > + > static int __init smc_init(void) > { > int rc; > @@ -3574,8 +3624,17 @@ static int __init smc_init(void) > pr_err("%s: smc_inet_init fails with %d\n", __func__, rc); > goto out_ulp; > } > + > + rc = bpf_smc_kfunc_init(); > + if (rc) { > + pr_err("%s: bpf_smc_kfunc_init fails with %d\n", __func__, rc); > + goto out_inet; > + } > + > static_branch_enable(&tcp_have_smc); > return 0; > +out_inet: > + smc_inet_exit(); > out_ulp: > tcp_unregister_ulp(&smc_ulp_ops); > out_lo: