From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="dv39pBPK" Received: from smtp-fw-52002.amazon.com (smtp-fw-52002.amazon.com [52.119.213.150]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2399BE8; Thu, 14 Dec 2023 07:56:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1702569393; x=1734105393; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sgNL2Xa6yNb10q58PGrl6m/1TKo0vIMxcvusxdjfRSc=; b=dv39pBPKNtTL3dNiCX/rVe2SOxzybAbFIWzvDo1q5Tl0IVQmLLUENS+N F5CMQglGDfW84zGSEIHfXccQ9wPTUODbyyTjhlF1UqB+fRBqJVqOIYcSh gVYThefRvTMT+a5rNsdWQuSyufrBZi9mUDCd0OOlntJDLiwp+hSlJHR5l A=; X-IronPort-AV: E=Sophos;i="6.04,275,1695686400"; d="scan'208";a="600625387" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-pdx-2c-m6i4x-8c5b1df3.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-52002.iad7.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Dec 2023 15:56:30 +0000 Received: from smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev (pdx2-ws-svc-p26-lb5-vlan3.pdx.amazon.com [10.39.38.70]) by email-inbound-relay-pdx-2c-m6i4x-8c5b1df3.us-west-2.amazon.com (Postfix) with ESMTPS id 9FE2B40D57; Thu, 14 Dec 2023 15:56:29 +0000 (UTC) Received: from EX19MTAUWB001.ant.amazon.com [10.0.21.151:60779] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.33.64:2525] with esmtp (Farcaster) id 6d7c8cf3-2e0d-4f6c-afcd-e4c9300d787a; Thu, 14 Dec 2023 15:56:29 +0000 (UTC) X-Farcaster-Flow-ID: 6d7c8cf3-2e0d-4f6c-afcd-e4c9300d787a Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWB001.ant.amazon.com (10.250.64.248) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Thu, 14 Dec 2023 15:56:28 +0000 Received: from 88665a182662.ant.amazon.com (10.143.92.5) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.40; Thu, 14 Dec 2023 15:56:25 +0000 From: Kuniyuki Iwashima To: Eric Dumazet , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v6 bpf-next 4/6] bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check(). Date: Fri, 15 Dec 2023 00:54:22 +0900 Message-ID: <20231214155424.67136-5-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231214155424.67136-1-kuniyu@amazon.com> References: <20231214155424.67136-1-kuniyu@amazon.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D035UWA004.ant.amazon.com (10.13.139.109) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: Bulk We will support arbitrary SYN Cookie with BPF in the following patch. If BPF prog validates ACK and kfunc allocates a reqsk, it will be carried to cookie_[46]_check() as skb->sk. If skb->sk is not NULL, we call cookie_bpf_check(). Then, we clear skb->sk and skb->destructor, which are needed not to hold refcnt for reqsk and the listener. See the following patch for details. After that, we finish initialisation for the remaining fields with cookie_tcp_reqsk_init(). Note that the server side WScale is set only for non-BPF SYN Cookie. Signed-off-by: Kuniyuki Iwashima --- include/net/tcp.h | 20 ++++++++++++++++++++ net/ipv4/syncookies.c | 31 +++++++++++++++++++++++++++---- net/ipv6/syncookies.c | 13 +++++++++---- 3 files changed, 56 insertions(+), 8 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index c77354d1b86d..b5d7149eb0f8 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -599,6 +599,26 @@ static inline bool cookie_ecn_ok(const struct net *net, const struct dst_entry * dst_feature(dst, RTAX_FEATURE_ECN); } +#if IS_ENABLED(CONFIG_BPF) +static inline bool cookie_bpf_ok(struct sk_buff *skb) +{ + return skb->sk; +} + +struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb); +#else +static inline bool cookie_bpf_ok(struct sk_buff *skb) +{ + return false; +} + +static inline struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + return NULL; +} +#endif + /* From net/ipv6/syncookies.c */ int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th); struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 981944c22820..be88bf586ff9 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -295,6 +295,24 @@ static int cookie_tcp_reqsk_init(struct sock *sk, struct sk_buff *skb, return 0; } +#if IS_ENABLED(CONFIG_BPF) +struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb) +{ + struct request_sock *req = inet_reqsk(skb->sk); + + skb->sk = NULL; + skb->destructor = NULL; + + if (cookie_tcp_reqsk_init(sk, skb, req)) { + reqsk_free(req); + req = NULL; + } + + return req; +} +EXPORT_SYMBOL_GPL(cookie_bpf_check); +#endif + struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk, struct sk_buff *skb, struct tcp_options_received *tcp_opt, @@ -395,9 +413,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) !th->ack || th->rst) goto out; - req = cookie_tcp_check(net, sk, skb); - if (IS_ERR(req)) - goto out; + if (cookie_bpf_ok(skb)) { + req = cookie_bpf_check(sk, skb); + } else { + req = cookie_tcp_check(net, sk, skb); + if (IS_ERR(req)) + goto out; + } if (!req) goto out_drop; @@ -445,7 +467,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) ireq->wscale_ok, &rcv_wscale, dst_metric(&rt->dst, RTAX_INITRWND)); - ireq->rcv_wscale = rcv_wscale; + if (!req->syncookie) + ireq->rcv_wscale = rcv_wscale; ireq->ecn_ok &= cookie_ecn_ok(net, &rt->dst); ret = tcp_get_cookie_sock(sk, skb, req, &rt->dst); diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index c8d2ca27220c..6b9c69278819 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -182,9 +182,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) !th->ack || th->rst) goto out; - req = cookie_tcp_check(net, sk, skb); - if (IS_ERR(req)) - goto out; + if (cookie_bpf_ok(skb)) { + req = cookie_bpf_check(sk, skb); + } else { + req = cookie_tcp_check(net, sk, skb); + if (IS_ERR(req)) + goto out; + } if (!req) goto out_drop; @@ -247,7 +251,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) ireq->wscale_ok, &rcv_wscale, dst_metric(dst, RTAX_INITRWND)); - ireq->rcv_wscale = rcv_wscale; + if (!req->syncookie) + ireq->rcv_wscale = rcv_wscale; ireq->ecn_ok &= cookie_ecn_ok(net, dst); ret = tcp_get_cookie_sock(sk, skb, req, dst); -- 2.30.2