From patchwork Fri May 12 20:22:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 13239664 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 7299D23D6C for ; Fri, 12 May 2023 20:23:33 +0000 (UTC) Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F515FC5 for ; Fri, 12 May 2023 13:23:30 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id ffacd0b85a97d-305f0491e62so9979697f8f.3 for ; Fri, 12 May 2023 13:23:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1683923009; x=1686515009; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=gjVap42SayboaOEeK2j683/O+m6yOzJSUISq3ieKrxY=; b=FnS3x/kT/KuAutUBtVPtRltv7UE1JoGOxrJ5Q59YqgM9Ac6hQaViHwWRz0E9km5o6U hum2tMwNO+xrC1qLbImkcsAbkmbBwGn6DislA+LIyNhjvLCCScY8X5LX+TO5GzV0Xold bGgh2+g0VH45IWCjES5kIxMCAv4ApTSWyiHMkhmVfqWN1P5skXxG5wNcKgxurKt5Cib2 kXLt1TEmAnD8PVUIEO4JumzNbxGmO8yRfxUP9jcFpKOUV0XcAsFlxjrBBzNYV5k/U5Pj Dz+M+hq7Rq8prWz9zWoTiTcBhNA3lKktm16a/7nPZZPJRYlRzkmu4PEwdKM3Kxc3yg6t VQBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683923009; x=1686515009; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=gjVap42SayboaOEeK2j683/O+m6yOzJSUISq3ieKrxY=; b=PyqMihOue+ThPNFXMlKO5S4mu7qgZAQjrWlk+sxdsRR0TDfnRw44Rh5qZZ9ql1CndG XhGEl1MW/Tj9i9zIVAIFuFOHWi+OppYZvPRKIrUg0wp9fc9dduOsgEcCry/BdID3Mx6f BuoyYkq6ovezVXP/GMDeX8kIXkj5vURihjmv9LFB1LZkvTpI/8AIf7s4yQnymPzH70sU zC3FgmWT8glKOQpRvQu4DKGeRB7Nqr61vfUC4vGvjQfdeiDmUBjrTjVveyWAsjzKngMN k2rySUfJRoIhcjIsOhOUn4NXgDoXR2XQgm1ClkGSx+tVw4fAUDWwemvyk1LJLXeKNWo6 WS2Q== X-Gm-Message-State: AC+VfDyFqZHrWdHCIqfF+UXEbQ3nCdcAp2Q03So8Az95Un7t1jB9EbSZ 47ylxksceOpF3sITk484P/FbHw== X-Google-Smtp-Source: ACHHUZ6NRB/X4H/Ltcbapm5zsIzAM3nYRHst8ZWWo88XUlFIiMjIvkHCKOYOMk+ktU5/EpuAsMz09g== X-Received: by 2002:a05:6000:1362:b0:307:7dc6:cce4 with SMTP id q2-20020a056000136200b003077dc6cce4mr20047685wrz.32.1683923008828; Fri, 12 May 2023 13:23:28 -0700 (PDT) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id n9-20020a05600c294900b003f423508c6bsm17304527wmd.44.2023.05.12.13.23.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 May 2023 13:23:28 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org, David Ahern , Eric Dumazet , Paolo Abeni , Jakub Kicinski , "David S. Miller" Cc: Dmitry Safonov , Andy Lutomirski , Ard Biesheuvel , Bob Gilligan , Dan Carpenter , David Laight , Dmitry Safonov <0x7f454c46@gmail.com>, Eric Biggers , "Eric W. Biederman" , Francesco Ruggeri , Herbert Xu , Hideaki YOSHIFUJI , Ivan Delalande , Leonard Crestez , Salam Noureddine , netdev@vger.kernel.org Subject: [PATCH v6 07/21] net/tcp: Add tcp_parse_auth_options() Date: Fri, 12 May 2023 21:22:57 +0100 Message-Id: <20230512202311.2845526-8-dima@arista.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230512202311.2845526-1-dima@arista.com> References: <20230512202311.2845526-1-dima@arista.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org Introduce a helper that: (1) shares the common code with TCP-MD5 header options parsing (2) looks for hash signature only once for both TCP-MD5 and TCP-AO (3) fails with -EEXIST if any TCP sign option is present twice, see RFC5925 (2.2): ">> A single TCP segment MUST NOT have more than one TCP-AO in its options sequence. When multiple TCP-AOs appear, TCP MUST discard the segment." Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov --- include/net/tcp.h | 24 +++++++++++++++++++++++- include/net/tcp_ao.h | 17 ++++++++++++++++- net/ipv4/tcp.c | 3 ++- net/ipv4/tcp_input.c | 39 +++++++++++++++++++++++++++++---------- net/ipv4/tcp_ipv4.c | 15 ++++++++++----- net/ipv6/tcp_ipv6.c | 11 +++++++---- 6 files changed, 87 insertions(+), 22 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 50d255ac3500..e93f9f0fb464 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -434,7 +434,6 @@ int tcp_mmap(struct file *file, struct socket *sock, void tcp_parse_options(const struct net *net, const struct sk_buff *skb, struct tcp_options_received *opt_rx, int estab, struct tcp_fastopen_cookie *foc); -const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); /* * BPF SKB-less helpers @@ -2535,6 +2534,29 @@ static inline u64 tcp_transmit_time(const struct sock *sk) return 0; } +static inline int tcp_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const struct tcp_ao_hdr **aoh) +{ + const u8 *md5_tmp, *ao_tmp; + int ret; + + ret = tcp_do_parse_auth_options(th, &md5_tmp, &ao_tmp); + if (ret) + return ret; + + if (md5_hash) + *md5_hash = md5_tmp; + + if (aoh) { + if (!ao_tmp) + *aoh = NULL; + else + *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); + } + + return 0; +} + static inline bool tcp_ao_required(struct sock *sk, const void *saddr, int family) { diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index ee32af145bba..72fc87cf58bf 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -156,7 +156,9 @@ int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb); void tcp_ao_connect_init(struct sock *sk); - +void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb, + struct tcp_request_sock *treq, + unsigned short int family); #else /* CONFIG_TCP_AO */ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, @@ -179,4 +181,17 @@ static inline void tcp_ao_connect_init(struct sock *sk) } #endif +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) +int tcp_do_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const u8 **ao_hash); +#else +static int tcp_do_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const u8 **ao_hash) +{ + *md5_hash = NULL; + *ao_hash = NULL; + return 0; +} +#endif + #endif /* _TCP_AO_H */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fa94d5c416b0..fe30260be4c2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4502,7 +4502,8 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, l3index = sdif ? dif : 0; hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family); - hash_location = tcp_parse_md5sig_option(th); + if (tcp_parse_auth_options(th, &hash_location, NULL)) + return true; /* We've parsed the options - do we have a hash? */ if (!hash_expected && !hash_location) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2a9010b4ac8c..9626c703caed 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4202,39 +4202,58 @@ static bool tcp_fast_parse_options(const struct net *net, return true; } -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) /* - * Parse MD5 Signature option + * Parse Signature options */ -const u8 *tcp_parse_md5sig_option(const struct tcphdr *th) +int tcp_do_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const u8 **ao_hash) { int length = (th->doff << 2) - sizeof(*th); const u8 *ptr = (const u8 *)(th + 1); + unsigned int minlen = TCPOLEN_MD5SIG; + + if (IS_ENABLED(CONFIG_TCP_AO)) + minlen = sizeof(struct tcp_ao_hdr) + 1; + + *md5_hash = NULL; + *ao_hash = NULL; /* If not enough data remaining, we can short cut */ - while (length >= TCPOLEN_MD5SIG) { + while (length >= minlen) { int opcode = *ptr++; int opsize; switch (opcode) { case TCPOPT_EOL: - return NULL; + return 0; case TCPOPT_NOP: length--; continue; default: opsize = *ptr++; if (opsize < 2 || opsize > length) - return NULL; - if (opcode == TCPOPT_MD5SIG) - return opsize == TCPOLEN_MD5SIG ? ptr : NULL; + return -EINVAL; + if (opcode == TCPOPT_MD5SIG) { + if (opsize != TCPOLEN_MD5SIG) + return -EINVAL; + if (unlikely(*md5_hash || *ao_hash)) + return -EEXIST; + *md5_hash = ptr; + } else if (opcode == TCPOPT_AO) { + if (opsize <= sizeof(struct tcp_ao_hdr)) + return -EINVAL; + if (unlikely(*md5_hash || *ao_hash)) + return -EEXIST; + *ao_hash = ptr; + } } ptr += opsize - 2; length -= opsize; } - return NULL; + return 0; } -EXPORT_SYMBOL(tcp_parse_md5sig_option); +EXPORT_SYMBOL(tcp_do_parse_auth_options); #endif /* Sorry, PAWS as specified is broken wrt. pure-ACKs -DaveM diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index bd9b9118e1f0..a88465ed5d39 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -668,7 +668,9 @@ EXPORT_SYMBOL(tcp_v4_send_check); * Exception: precedence violation. We do not implement it in any case. */ -#ifdef CONFIG_TCP_MD5SIG +#ifdef CONFIG_TCP_AO +#define OPTION_BYTES MAX_TCP_OPTION_SPACE +#elif defined(CONFIG_TCP_MD5SIG) #define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED #else #define OPTION_BYTES sizeof(__be32) @@ -684,7 +686,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) struct ip_reply_arg arg; #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *key = NULL; - const __u8 *hash_location = NULL; + const __u8 *md5_hash_location = NULL; unsigned char newhash[16]; int genhash; struct sock *sk1 = NULL; @@ -724,8 +726,11 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); #ifdef CONFIG_TCP_MD5SIG + /* Invalid TCP option size or twice included auth */ + if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, NULL)) + return; + rcu_read_lock(); - hash_location = tcp_parse_md5sig_option(th); if (sk && sk_fullsock(sk)) { const union tcp_md5_addr *addr; int l3index; @@ -736,7 +741,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); - } else if (hash_location) { + } else if (md5_hash_location) { const union tcp_md5_addr *addr; int sdif = tcp_v4_sdif(skb); int dif = inet_iif(skb); @@ -768,7 +773,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); - if (genhash || memcmp(hash_location, newhash, 16) != 0) + if (genhash || memcmp(md5_hash_location, newhash, 16) != 0) goto out; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 7ff755e27686..0074d1f1f8a5 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -993,7 +993,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) u32 seq = 0, ack_seq = 0; struct tcp_md5sig_key *key = NULL; #ifdef CONFIG_TCP_MD5SIG - const __u8 *hash_location = NULL; + const __u8 *md5_hash_location = NULL; unsigned char newhash[16]; int genhash; struct sock *sk1 = NULL; @@ -1015,8 +1015,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); #ifdef CONFIG_TCP_MD5SIG + /* Invalid TCP option size or twice included auth */ + if (tcp_parse_auth_options(th, &md5_hash_location, NULL)) + return; + rcu_read_lock(); - hash_location = tcp_parse_md5sig_option(th); if (sk && sk_fullsock(sk)) { int l3index; @@ -1025,7 +1028,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) */ l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index); - } else if (hash_location) { + } else if (md5_hash_location) { int dif = tcp_v6_iif_l3_slave(skb); int sdif = tcp_v6_sdif(skb); int l3index; @@ -1054,7 +1057,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) goto out; genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb); - if (genhash || memcmp(hash_location, newhash, 16) != 0) + if (genhash || memcmp(md5_hash_location, newhash, 16) != 0) goto out; } #endif