From patchwork Fri Sep 27 03:42:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13813826 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) (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 980B94690; Fri, 27 Sep 2024 03:42:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.101 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727408567; cv=none; b=N/cF4Tl2HSbHyKQSg/cZ5/K3pqOFY2uw50fNc9N5hb9cscAIjMXY3+KZWr4tGB+tCf7feQJsljnWn5EOFmZ+jRwDc3wu6YuxmOWSJZF+ba544b//MhINkc2TuR44mgaJtfxHxCZyOyPmOcg1luD1DTRYZQibeXhyo+HFCjiHJmk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727408567; c=relaxed/simple; bh=+rq/57LVDrunt6xHzwvsK3DLj4lxyeZkeBq5OgbqtU4=; h=From:To:Cc:Subject:Date:Message-Id; b=g3RsAQ0Rqi4F3oAMg5RKSs6evJRMMDpZSYTwmOzdZmyi4oHFR9tN11sOx+AKFYHDrzKd1zfk0vBXJA+94ft0LSulShOCc9MODvHUulOZM008VyvvJ3EmQeVc4e0CYoH7zXO3Yt8GeApeIE1pUYzwhDmaMa4MusCeCfb8NKfIrk8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=goTZ20WM; arc=none smtp.client-ip=115.124.30.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="goTZ20WM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1727408554; h=From:To:Subject:Date:Message-Id; bh=OnJD+ij/8yrRC3fqRebt885INetiaIWT9sV8E+wPrGo=; b=goTZ20WMoQHpX5wd0BVKHp/plXUqJF9ZtX1IWBwBKbE1hSbDYsuEzu35ql3t5qjMBwLkSUQGmzYi3IuyA7CZ78vBGHkaz1ohPXWNvAOx8WpQV33O5bZm/7zv7IYmgMOTC+J7NzI23ZJ5A370llEx1bkqULU8lCinKE6QDbcuXoY= Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WFp1DhC_1727408550) by smtp.aliyun-inc.com; Fri, 27 Sep 2024 11:42:34 +0800 From: "D. Wythe" To: 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 Subject: [RFC PATCH net-next v2] net/smc: Introduce a hook to modify syn_smc at runtime Date: Fri, 27 Sep 2024 11:42:29 +0800 Message-Id: <1727408549-106551-1-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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}; 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: