From patchwork Mon Jan 24 12:12:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 534617 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF2F9C4167E for ; Mon, 24 Jan 2022 12:14:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239702AbiAXMOO (ORCPT ); Mon, 24 Jan 2022 07:14:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239179AbiAXMNx (ORCPT ); Mon, 24 Jan 2022 07:13:53 -0500 Received: from mail-ed1-x52a.google.com (mail-ed1-x52a.google.com [IPv6:2a00:1450:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 822C8C06173B; Mon, 24 Jan 2022 04:13:36 -0800 (PST) Received: by mail-ed1-x52a.google.com with SMTP id p12so56230841edq.9; Mon, 24 Jan 2022 04:13:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=kgwpa/nfD6Ba4i91nDFUIWWvs0ArnF+hSW7LgNcf6rE=; b=g8eOZt/yXkPSSVZsS2dcITsg6fYbYuis6CyPatnKCrBWgppXNOsNe2s7oKTZ8ydIQk h544LP/z4awYUUF8rWeQ0pNLwDNjqIEyXjm2bf3QpBxxNddTpqk5D79NCaY0E2ALqQl5 xftqFXI4Ob/Jm/7toTeBZMjjQ3O58qUSt0Emiclwcba7TDnvTo1vNSDZ20lTJtf5X2Km 5ohDel38JjNL6jFbSzBSRwSPSp7G7BXvcBaSwbzY/GYOHyVzNRxdOqm0LLgAf4PuUmqu pXwQvp3vCOhxPqQo+UMpTyvyFdjjVd1N287F19Bty239ptr8q4qawVEa9rKXL7fkjIEa Ajjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=kgwpa/nfD6Ba4i91nDFUIWWvs0ArnF+hSW7LgNcf6rE=; b=6NAVPI5F3/6Q1WVIO5ZM4Ry++qfWf1Z/tb2WBo5OWB9xKFq58HcND6hQ8B0I/Vbf8a LSylVAkYwyendsPKyCPFk2VRMr0ATqn+mEaxuMZ8rsLIvjLM8jv8xWyzbhaSiNdu8c2a 4rgnr+hsIvDb5KE2itwDdAuptbOiYYLJ/GXxHFs+wtMa4WdMf4sj+36v7nn6pNKW7QSi B2yTJEK8pNV/Vz0HyBZdZPYjfWE/Mb56L++d6rJKEiw91zPlyJ4tvINYZiD6UPZPyGvI IYZYCLfdNbp+3Z6nQ7bnPiQwJ3u2+8TOoXyhNPX7HTq0DUjZLjjgwIWvDTcbS+8dGTtm 3ULg== X-Gm-Message-State: AOAM531oIBKRTvK9vztQVgmUGO5N6dafCMvdIt13M0NZa92fx8yjomol Lq4emDpNTzhugfgwET+ODJ8= X-Google-Smtp-Source: ABdhPJwOcTDY2FAgRFkSXe7fQGCPq2S4k26eOKhwbyI5YImvYENnfXxJJMJtyeXTgnSr0GuSc1veyQ== X-Received: by 2002:a05:6402:5246:: with SMTP id t6mr8070016edd.35.1643026415069; Mon, 24 Jan 2022 04:13:35 -0800 (PST) Received: from ponky.lan ([2a04:241e:502:a09c:a21f:7a9f:9158:4a40]) by smtp.gmail.com with ESMTPSA id b16sm4847517eja.211.2022.01.24.04.13.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 04:13:34 -0800 (PST) From: Leonard Crestez To: David Ahern , Eric Dumazet , Philip Paeps , Dmitry Safonov <0x7f454c46@gmail.com> Cc: Shuah Khan , "David S. Miller" , Herbert Xu , Kuniyuki Iwashima , Hideaki YOSHIFUJI , Jakub Kicinski , Yuchung Cheng , Francesco Ruggeri , Mat Martineau , Christoph Paasch , Ivan Delalande , Priyaranjan Jha , netdev@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 08/20] tcp: authopt: Implement Sequence Number Extension Date: Mon, 24 Jan 2022 14:12:54 +0200 Message-Id: <4e554642d04304ef61797f5ddc7dc22a2a081eee.1643026076.git.cdleonard@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add a compute_sne function which finds the value of SNE for a certain SEQ given an already known "recent" SNE/SEQ. This is implemented using the standard tcp before/after macro and will work for SEQ values that are without 2^31 of the SEQ for which we know the SNE. For updating we advance the value for rcv_sne at the same time as rcv_nxt and for snd_sne at the same time as snd_nxt. We could track other values (for example snd_una) but this is good enough and works very easily for timewait socket. This implementation is different from RFC suggestions and doesn't require additional flags. It does pass tests from this draft: https://datatracker.ietf.org/doc/draft-touch-sne/ Signed-off-by: Leonard Crestez --- include/net/tcp_authopt.h | 34 ++++++++++++++ net/ipv4/tcp_authopt.c | 98 ++++++++++++++++++++++++++++++++++++++- net/ipv4/tcp_input.c | 1 + net/ipv4/tcp_output.c | 1 + 4 files changed, 132 insertions(+), 2 deletions(-) diff --git a/include/net/tcp_authopt.h b/include/net/tcp_authopt.h index 4c9ec1f39932..6e9b5ca22f62 100644 --- a/include/net/tcp_authopt.h +++ b/include/net/tcp_authopt.h @@ -66,10 +66,14 @@ struct tcp_authopt_info { u32 flags; /** @src_isn: Local Initial Sequence Number */ u32 src_isn; /** @dst_isn: Remote Initial Sequence Number */ u32 dst_isn; + /** @rcv_sne: Recv-side Sequence Number Extension tracking tcp_sock.rcv_nxt */ + u32 rcv_sne; + /** @snd_sne: Send-side Sequence Number Extension tracking tcp_sock.snd_nxt */ + u32 snd_sne; }; /* TCP authopt as found in header */ struct tcphdr_authopt { u8 num; @@ -185,10 +189,34 @@ static inline int tcp_authopt_inbound_check_req(struct request_sock *req, struct if (info) return __tcp_authopt_inbound_check((struct sock *)req, skb, info, opt); } return 0; } +void __tcp_authopt_update_rcv_sne(struct tcp_sock *tp, struct tcp_authopt_info *info, u32 seq); +static inline void tcp_authopt_update_rcv_sne(struct tcp_sock *tp, u32 seq) +{ + struct tcp_authopt_info *info; + + if (tcp_authopt_needed) { + info = rcu_dereference_protected(tp->authopt_info, + lockdep_sock_is_held((struct sock *)tp)); + if (info) + __tcp_authopt_update_rcv_sne(tp, info, seq); + } +} +void __tcp_authopt_update_snd_sne(struct tcp_sock *tp, struct tcp_authopt_info *info, u32 seq); +static inline void tcp_authopt_update_snd_sne(struct tcp_sock *tp, u32 seq) +{ + struct tcp_authopt_info *info; + + if (tcp_authopt_needed) { + info = rcu_dereference_protected(tp->authopt_info, + lockdep_sock_is_held((struct sock *)tp)); + if (info) + __tcp_authopt_update_snd_sne(tp, info, seq); + } +} #else static inline int tcp_set_authopt(struct sock *sk, sockptr_t optval, unsigned int optlen) { return -ENOPROTOOPT; } @@ -235,8 +263,14 @@ static inline int tcp_authopt_inbound_check(struct sock *sk, struct sk_buff *skb static inline int tcp_authopt_inbound_check_req(struct request_sock *sk, struct sk_buff *skb, const u8 *opt) { return 0; } +static inline void tcp_authopt_update_rcv_sne(struct tcp_sock *tp, u32 seq) +{ +} +static inline void tcp_authopt_update_snd_sne(struct tcp_sock *tp, u32 seq) +{ +} #endif #endif /* _LINUX_TCP_AUTHOPT_H */ diff --git a/net/ipv4/tcp_authopt.c b/net/ipv4/tcp_authopt.c index 939dfb4a6f12..5e240b4ada60 100644 --- a/net/ipv4/tcp_authopt.c +++ b/net/ipv4/tcp_authopt.c @@ -649,10 +649,97 @@ static int tcp_authopt_get_isn(struct sock *sk, *disn = htonl(info->dst_isn); } return 0; } +/* compute_sne - Calculate Sequence Number Extension + * + * Give old upper/lower 32bit values and a new lower 32bit value determine the + * new value of the upper 32 bit. The new sequence number can be 2^31 before or + * after prev_seq but TCP window scaling should limit this further. + * + * For correct accounting the stored SNE value should be only updated together + * with the SEQ. + */ +static u32 compute_sne(u32 sne, u32 prev_seq, u32 seq) +{ + if (before(seq, prev_seq)) { + if (seq > prev_seq) + --sne; + } else { + if (seq < prev_seq) + ++sne; + } + + return sne; +} + +/* Update rcv_sne, must be called immediately before rcv_nxt update */ +void __tcp_authopt_update_rcv_sne(struct tcp_sock *tp, + struct tcp_authopt_info *info, u32 seq) +{ + info->rcv_sne = compute_sne(info->rcv_sne, tp->rcv_nxt, seq); +} + +/* Update snd_sne, must be called immediately before snd_nxt update */ +void __tcp_authopt_update_snd_sne(struct tcp_sock *tp, + struct tcp_authopt_info *info, u32 seq) +{ + info->snd_sne = compute_sne(info->snd_sne, tp->snd_nxt, seq); +} + +/* Compute SNE for a specific packet (by seq). */ +static int compute_packet_sne(struct sock *sk, struct tcp_authopt_info *info, + u32 seq, bool input, __be32 *sne) +{ + u32 rcv_nxt, snd_nxt; + + // For TCP_NEW_SYN_RECV we have no tcp_authopt_info but tcp_request_sock holds ISN. + if (sk->sk_state == TCP_NEW_SYN_RECV) { + struct tcp_request_sock *rsk = tcp_rsk((struct request_sock *)sk); + + if (input) + *sne = htonl(compute_sne(0, rsk->rcv_isn, seq)); + else + *sne = htonl(compute_sne(0, rsk->snt_isn, seq)); + return 0; + } + + /* TCP_LISTEN only receives SYN */ + if (sk->sk_state == TCP_LISTEN && input) + return 0; + + /* TCP_SYN_SENT only sends SYN and receives SYN/ACK + * For the input case rcv_nxt is initialized after the packet is + * validated so tcp_sk(sk)->rcv_nxt is not initialized. + */ + if (sk->sk_state == TCP_SYN_SENT) + return 0; + + if (sk->sk_state == TCP_TIME_WAIT) { + rcv_nxt = tcp_twsk(sk)->tw_rcv_nxt; + snd_nxt = tcp_twsk(sk)->tw_snd_nxt; + } else { + if (WARN_ONCE(!sk_fullsock(sk), + "unexpected minisock sk=%p state=%d", sk, + sk->sk_state)) + return -EINVAL; + rcv_nxt = tcp_sk(sk)->rcv_nxt; + snd_nxt = tcp_sk(sk)->snd_nxt; + } + + if (WARN_ONCE(!info, "unexpected missing info for sk=%p sk_state=%d", sk, sk->sk_state)) + return -EINVAL; + + if (input) + *sne = htonl(compute_sne(info->rcv_sne, rcv_nxt, seq)); + else + *sne = htonl(compute_sne(info->snd_sne, snd_nxt, seq)); + + return 0; +} + /* Feed one buffer into ahash * The buffer is assumed to be DMA-able */ static int crypto_ahash_buf(struct ahash_request *req, u8 *buf, uint len) { @@ -684,10 +771,13 @@ int __tcp_authopt_openreq(struct sock *newsk, const struct sock *oldsk, struct r if (!new_info) return -ENOMEM; new_info->src_isn = tcp_rsk(req)->snt_isn; new_info->dst_isn = tcp_rsk(req)->rcv_isn; + /* Caller is tcp_create_openreq_child and already initializes snd_nxt/rcv_nxt */ + new_info->snd_sne = compute_sne(0, new_info->src_isn, tcp_sk(newsk)->snd_nxt); + new_info->rcv_sne = compute_sne(0, new_info->dst_isn, tcp_sk(newsk)->rcv_nxt); sk_gso_disable(newsk); rcu_assign_pointer(tcp_sk(newsk)->authopt_info, new_info); return 0; } @@ -695,10 +785,12 @@ int __tcp_authopt_openreq(struct sock *newsk, const struct sock *oldsk, struct r void __tcp_authopt_finish_connect(struct sock *sk, struct sk_buff *skb, struct tcp_authopt_info *info) { info->src_isn = ntohl(tcp_hdr(skb)->ack_seq) - 1; info->dst_isn = ntohl(tcp_hdr(skb)->seq); + info->snd_sne = compute_sne(0, info->src_isn, tcp_sk(sk)->snd_nxt); + info->rcv_sne = compute_sne(0, info->dst_isn, tcp_sk(sk)->rcv_nxt); } /* feed traffic key into ahash */ static int tcp_authopt_ahash_traffic_key(struct tcp_authopt_alg_pool *pool, struct sock *sk, @@ -952,14 +1044,16 @@ static int tcp_authopt_hash_packet(struct tcp_authopt_alg_pool *pool, bool ipv6, bool include_options, u8 *macbuf) { struct tcphdr *th = tcp_hdr(skb); + __be32 sne = 0; int err; - /* NOTE: SNE unimplemented */ - __be32 sne = 0; + err = compute_packet_sne(sk, info, ntohl(th->seq), input, &sne); + if (err) + return err; err = crypto_ahash_init(pool->req); if (err) return err; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5bdb8c31b943..91f1b04c1933 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3517,10 +3517,11 @@ static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack) static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq) { u32 delta = seq - tp->rcv_nxt; sock_owned_by_me((struct sock *)tp); + tcp_authopt_update_rcv_sne(tp, seq); tp->bytes_received += delta; WRITE_ONCE(tp->rcv_nxt, seq); } /* Update our send window. diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b959e8b949b6..6a6024a0b9e9 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -67,10 +67,11 @@ static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb) { struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); unsigned int prior_packets = tp->packets_out; + tcp_authopt_update_snd_sne(tp, TCP_SKB_CB(skb)->end_seq); WRITE_ONCE(tp->snd_nxt, TCP_SKB_CB(skb)->end_seq); __skb_unlink(skb, &sk->sk_write_queue); tcp_rbtree_insert(&sk->tcp_rtx_queue, skb);