From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 0E37E45027; Mon, 30 Sep 2024 07:15:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727680561; cv=none; b=RaioUj5LImg7GdwMmLFTpjkfwnuOtV1SJkguLxXop9t07MiCewc/uaRZwu6rxgiZbTQLkw5m/SOhKfheuufLHPzz/25KW9ffOW4NebnTysly6FHbsePIpTncdPHaUY/ae6z7UrhhuArjvgMRLPwdh/UMErFX/aOSnEs3VD4oeDo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727680561; c=relaxed/simple; bh=woMxg/j4NP6XZd49rIGatAG25hIrZzeXyxPnCn/FYPg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VFbSWjLYUCl6ol1doOjYgP31EQCDvHC2s226vqW4obA5AXxTH50ApodZCQCygD65DId/1WqLEIpBgbvXTaLUS214DIRtyBBHScd2aovon0XVqGC5iprWqRVI6KlhMkUU5MnHWWKO1yHOErPHSiBcWN5b8VWv2R/98EU4ucvuDYQ= 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=PsX4i5iU; arc=none smtp.client-ip=115.124.30.132 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="PsX4i5iU" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1727680550; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=JZL/ku9aK9zw7vcczmtqa5/1hHelV84Np4wXlJZ7rek=; b=PsX4i5iUM0+n2ProvPT6uiNcHZEsP6TcKgCZwiaE298gfOrJbmrO7UYLAGx3fCYNGcUKNxurI3jD8IZ0PJOuFXDJKfIlwmfobBxoR/d8u1eIO+6OqZwQr1tXorquIXg8iMzqTsggn9YSX3/+vRmpDaJkmJND8EsDf5Y/TkxDYGk= Received: from 30.221.144.234(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WG-IUOL_1727680548) by smtp.aliyun-inc.com; Mon, 30 Sep 2024 15:15:49 +0800 Message-ID: Date: Mon, 30 Sep 2024 15:15:47 +0800 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH net-next v2] net/smc: Introduce a hook to modify syn_smc at runtime To: Zhu Yanjun , 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> Content-Language: en-US From: "D. Wythe" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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. 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: