From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) (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 D52C618C354 for ; Mon, 30 Sep 2024 10:47:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727693246; cv=none; b=IGVPKTwHJ5JrSHPaXZP2zW/4VlNJkT//vo/32xtJdyDrGX2ws6vpPcROd2K2S6jNvW+EF8N81W9++ky4m9uwQ0+DiTDoUOTWt9G0pO6shx5zn64VzPmVCzNMIIzutrD9PuIrrKbuE1u8zL2mdHSuLIE5qP3+SnXl5KZkEhrg2Do= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727693246; c=relaxed/simple; bh=IlvOQtnXuq3xZ8kUhJ9RstN8JRxm/RPKmIg6stNPLXU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LrRFzSDHprDPXiiDFkI7+m7KqWJztAJasVCHrvV56pUTwzDubvYePgkqgHEO+AE2X6URiuOjFOUjvMdAI2GOsZN4yKWya0GPFY5so/MPQ7aDAlwny0etJk5JSQmMzcv1u4edcucGwXkIlNs3HMvpgBTX86c51Xs9eX8cM+H2R6Y= 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=T6bJ6jns; arc=none smtp.client-ip=91.218.175.183 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="T6bJ6jns" Message-ID: <2cb8660b-d582-4cef-9c44-80fd6f5c1d6c@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1727693241; 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=MvsrZvXNV+xHyTyAw9XvrzBOm3pa/0kyhjZhwvo6qCg=; b=T6bJ6jnsDzd/JJzjtHEcXFklth5pEO36upIoRK9QbErB3jnmFURh5Myx1tICjOlapNLjbI xnpMX5gtvG2K8c56TbzDQXCLH5aa6z7SgzkxyA6BtkAjseWnveefcmZlEcDkJzEgLjVnB3 A/kjffKXqcB7o7j+Ho+CTtNNev589C8= Date: Mon, 30 Sep 2024 18:46:57 +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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2024/9/30 15:15, D. Wythe 写道: > > > On 9/29/24 7:56 PM, Zhu Yanjun wrote: >> 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 > > > This is truly new information to me. Can you provide me with some > discussion links? > Thanks. It is a trivial problem. This is the link https://www.spinics.net/lists/linux-rdma/msg119815.html Zhu Yanjun > > D. Wythe > > >> >>>       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: