From patchwork Fri Jul 21 16:18:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 13322289 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 DCAB520F98 for ; Fri, 21 Jul 2023 16:19:54 +0000 (UTC) Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADF7B2D47 for ; Fri, 21 Jul 2023 09:19:38 -0700 (PDT) Received: by mail-lj1-x22a.google.com with SMTP id 38308e7fff4ca-2b703caf344so30471781fa.1 for ; Fri, 21 Jul 2023 09:19:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1689956377; x=1690561177; 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=8pdvJndqIykx+0FJxNSmcRlWy12cOp5LRT2bi6J8u9I=; b=BUyXERDPbZvXBZSPfVFgd8d2dYKYmneMIIzUOT8f2rR+5L56s5fgYRX79rHARrjR7X DrczbbZ2mC2U/kCBcntXeAH+CyA4AaH8fLCAl9ni6b9NmPyfP2fAzmV0N+I0IrxL1/04 zJtetgnry7CGDmOQmOIBiE4Wh/nUYNa9M4c3GU9ZG3HX0JPPoysUfP19SNxPOX7UqXsw vpmHO0lya6todpjRBctYuBf/vxqnvlvdk3kMdBAKFuhwlR5hk/Iderb1mg+KpV64wreN lurkwkKQ5u4o1eO+DNJo9T0yPCAsTBI9UvJ0yA0jLmvGzVWYL5SZf4JZ0GyV29Bp+4c4 GKnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689956377; x=1690561177; 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=8pdvJndqIykx+0FJxNSmcRlWy12cOp5LRT2bi6J8u9I=; b=HZWdbjBvACNNPvNAbqeXAX9/PGDcRxphZ+8lA6+phBNz97CJHhLzD+PrbKDiqVCejQ UYpTEBFe9WxQUo/gkP8Zs3iSQvrhZajf2fOWGCLk9oN/c2TD0mc3aIkG0rYKxj0Ufzsn Wp0H3P8R+QhQLxuj90PIGnoTEKTfDDkhO9odHEODHju5y6zxP+eezfZz2DIiiWkjDJ4b 67Y9ALyB0G69XtHwA+LXVTXq54J0UwNyc6ZXxWydAPXC16Kb9p8RQ8/DviEf7ez8aUj5 AgBnFPlyGLHwsZq9r0w3Q7qkVP1VIS3QRhoT45g1jBEdLftBQToI3kpfU8TqeKI37ZQ/ t0nA== X-Gm-Message-State: ABy/qLa9Q/QLbmhj5M1PXgFHqLj3/jns84gawGv0uONLodDJiJak0org rEYidZXrjziDNey4Uok4PboSyA== X-Google-Smtp-Source: APBJJlEaN++TvphG7yibWGXr0dIUddJyMpZ+Spgf9uNjYZCmCnJw8MYYPonkfVzx/eJZGxPUMy1SQQ== X-Received: by 2002:a2e:990d:0:b0:2b6:9dd5:7a5 with SMTP id v13-20020a2e990d000000b002b69dd507a5mr1862232lji.12.1689956376763; Fri, 21 Jul 2023 09:19:36 -0700 (PDT) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id l19-20020a7bc453000000b003fbc681c8d1sm6390210wmi.36.2023.07.21.09.19.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Jul 2023 09:19:36 -0700 (PDT) From: Dmitry Safonov To: David Ahern , Eric Dumazet , Paolo Abeni , Jakub Kicinski , "David S. Miller" Cc: linux-kernel@vger.kernel.org, Dmitry Safonov , Andy Lutomirski , Ard Biesheuvel , Bob Gilligan , Dan Carpenter , David Laight , Dmitry Safonov <0x7f454c46@gmail.com>, Donald Cassidy , Eric Biggers , "Eric W. Biederman" , Francesco Ruggeri , "Gaillardetz, Dominik" , Herbert Xu , Hideaki YOSHIFUJI , Ivan Delalande , Leonard Crestez , Salam Noureddine , "Tetreault, Francois" , netdev@vger.kernel.org Subject: [PATCH v8.1 net-next 07/23] net/tcp: Add tcp_parse_auth_options() Date: Fri, 21 Jul 2023 17:18:58 +0100 Message-ID: <20230721161916.542667-8-dima@arista.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721161916.542667-1-dima@arista.com> References: <20230721161916.542667-1-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_BLOCKED,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/dropreason-core.h | 6 ++++++ 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 ++++++---- 7 files changed, 93 insertions(+), 22 deletions(-) diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h index f291a3b0f9e5..05255bffa2c8 100644 --- a/include/net/dropreason-core.h +++ b/include/net/dropreason-core.h @@ -20,6 +20,7 @@ FN(IP_NOPROTO) \ FN(SOCKET_RCVBUFF) \ FN(PROTO_MEM) \ + FN(TCP_AUTH_HDR) \ FN(TCP_MD5NOTFOUND) \ FN(TCP_MD5UNEXPECTED) \ FN(TCP_MD5FAILURE) \ @@ -140,6 +141,11 @@ enum skb_drop_reason { * drop out of udp_memory_allocated. */ SKB_DROP_REASON_PROTO_MEM, + /** + * @SKB_DROP_REASON_TCP_AUTH_HDR: TCP-MD5 or TCP-AO hashes are met + * twice or set incorrectly. + */ + SKB_DROP_REASON_TCP_AUTH_HDR, /** * @SKB_DROP_REASON_TCP_MD5NOTFOUND: no MD5 hash and one expected, * corresponding to LINUX_MIB_TCPMD5NOTFOUND diff --git a/include/net/tcp.h b/include/net/tcp.h index d4344cc39893..17991a6848ff 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -428,7 +428,6 @@ 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 @@ -2571,6 +2570,29 @@ 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 8d61f2690d52..e97dfdc11451 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -150,7 +150,9 @@ 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, @@ -173,4 +175,17 @@ 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 d0b0565fa11e..c90b3c6df620 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4395,7 +4395,8 @@ 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 SKB_DROP_REASON_TCP_AUTH_HDR; /* 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 7780ceef3415..d9241385468a 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4212,39 +4212,58 @@ 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 8222f14e4c32..0e9c6cfd4ab2 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -670,7 +670,9 @@ 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) @@ -686,7 +688,7 @@ 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; @@ -727,8 +729,11 @@ 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; @@ -739,7 +744,7 @@ 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); @@ -771,7 +776,7 @@ 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 1dd7c8f3aff4..4c645160362e 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -989,7 +989,7 @@ 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; @@ -1011,8 +1011,11 @@ 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; @@ -1021,7 +1024,7 @@ 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; @@ -1050,7 +1053,7 @@ 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