[v8.1,net-next,08/23] net/tcp: Add AO sign to RST packets

Message ID	20230721161916.542667-9-dima@arista.com (mailing list archive)
State	Changes Requested
Delegated to:	Netdev Maintainers
Headers	show 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 3721120F98 for <netdev@vger.kernel.org>; Fri, 21 Jul 2023 16:19:57 +0000 (UTC) From: Dmitry Safonov <dima@arista.com> To: David Ahern <dsahern@kernel.org>, Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Jakub Kicinski <kuba@kernel.org>, "David S. Miller" <davem@davemloft.net> Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <dima@arista.com>, Andy Lutomirski <luto@amacapital.net>, Ard Biesheuvel <ardb@kernel.org>, Bob Gilligan <gilligan@arista.com>, Dan Carpenter <error27@gmail.com>, David Laight <David.Laight@aculab.com>, Dmitry Safonov <0x7f454c46@gmail.com>, Donald Cassidy <dcassidy@redhat.com>, Eric Biggers <ebiggers@kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, Francesco Ruggeri <fruggeri05@gmail.com>, "Gaillardetz, Dominik" <dgaillar@ciena.com>, Herbert Xu <herbert@gondor.apana.org.au>, Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>, Ivan Delalande <colona@arista.com>, Leonard Crestez <cdleonard@gmail.com>, Salam Noureddine <noureddine@arista.com>, "Tetreault, Francois" <ftetreau@ciena.com>, netdev@vger.kernel.org Subject: [PATCH v8.1 net-next 08/23] net/tcp: Add AO sign to RST packets Date: Fri, 21 Jul 2023 17:18:59 +0100 Message-ID: <20230721161916.542667-9-dima@arista.com> In-Reply-To: <20230721161916.542667-1-dima@arista.com> References: <20230721161916.542667-1-dima@arista.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	net/tcp: Add TCP-AO support \| expand [v8.1,net-next,00/23] net/tcp: Add TCP-AO support [v8.1,net-next,01/23] net/tcp: Prepare tcp_md5sig_pool for TCP-AO [v8.1,net-next,02/23] net/tcp: Add TCP-AO config and structures [v8.1,net-next,03/23] net/tcp: Introduce TCP_AO setsockopt()s [v8.1,net-next,04/23] net/tcp: Prevent TCP-MD5 with TCP-AO being set [v8.1,net-next,05/23] net/tcp: Calculate TCP-AO traffic keys [v8.1,net-next,06/23] net/tcp: Add TCP-AO sign to outgoing packets [v8.1,net-next,07/23] net/tcp: Add tcp_parse_auth_options() [v8.1,net-next,08/23] net/tcp: Add AO sign to RST packets [v8.1,net-next,09/23] net/tcp: Add TCP-AO sign to twsk [v8.1,net-next,10/23] net/tcp: Wire TCP-AO to request sockets [v8.1,net-next,11/23] net/tcp: Sign SYN-ACK segments with TCP-AO [v8.1,net-next,12/23] net/tcp: Verify inbound TCP-AO signed segments [v8.1,net-next,13/23] net/tcp: Add TCP-AO segments counters [v8.1,net-next,14/23] net/tcp: Add TCP-AO SNE support [v8.1,net-next,15/23] net/tcp: Add tcp_hash_fail() ratelimited logs [v8.1,net-next,16/23] net/tcp: Ignore specific ICMPs for TCP-AO connections [v8.1,net-next,17/23] net/tcp: Add option for TCP-AO to (not) hash header [v8.1,net-next,18/23] net/tcp: Add TCP-AO getsockopt()s [v8.1,net-next,19/23] net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs) [v8.1,net-next,20/23] net/tcp: Add static_key for TCP-AO [v8.1,net-next,21/23] net/tcp: Wire up l3index to TCP-AO [v8.1,net-next,22/23] net/tcp: Add TCP_AO_REPAIR [v8.1,net-next,23/23] Documentation/tcp: Add TCP-AO documentation

Context	Check	Description
netdev/series_format	fail	Series longer than 15 patches (and no cover letter)
netdev/tree_selection	success	Clearly marked for net-next, async
netdev/fixes_present	success	Fixes tag not required for -next series
netdev/header_inline	success	No static functions without inline keyword in header files
netdev/build_32bit	success	Errors and warnings before: 2330 this patch: 2330
netdev/cc_maintainers	success	CCed 6 of 6 maintainers
netdev/build_clang	success	Errors and warnings before: 1486 this patch: 1486
netdev/verify_signedoff	success	Signed-off-by tag matches author and committer
netdev/deprecated_api	success	None detected
netdev/check_selftest	success	No net selftest shell script
netdev/verify_fixes	success	No Fixes tag
netdev/build_allmodconfig_warn	success	Errors and warnings before: 2360 this patch: 2360
netdev/checkpatch	warning	CHECK: Alignment should match open parenthesis WARNING: else is not generally useful after a break or return WARNING: line length of 83 exceeds 80 columns
netdev/kdoc	success	Errors and warnings before: 0 this patch: 0
netdev/source_inline	success	Was 0 now: 0

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index e97dfdc11451..6e8567b5bbf8 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -117,12 +117,24 @@ int tcp_ao_hash_skb(unsigned short int family, const u8 *tkey, int hash_offset, u32 sne); int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, sockptr_t optval, int optlen); +struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, + int sndid, int rcvid); int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, unsigned int len, struct tcp_sigpool *hp); void tcp_ao_destroy_sock(struct sock *sk); struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr, int family, int sndid, int rcvid, u16 port); +int tcp_ao_hash_hdr(unsigned short family, char *ao_hash, + struct tcp_ao_key *key, const u8 *tkey, + const union tcp_ao_addr *daddr, + const union tcp_ao_addr *saddr, + const struct tcphdr *th, u32 sne); +int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, + const struct tcp_ao_hdr *aoh, int l3index, u32 seq, + struct tcp_ao_key **key, char **traffic_key, + bool *allocated_traffic_key, u8 *keyid, u32 *sne); + /* ipv4 specific functions */ int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen); struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index 3ff7b1efacfa..b8b2e9caa096 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -48,8 +48,8 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, * it's known that the keys in ao_info are matching peer's * family/address/port/VRF/etc. */ -static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, - int sndid, int rcvid) +struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, + int sndid, int rcvid) { struct tcp_ao_key *key; @@ -371,6 +371,66 @@ static int tcp_ao_hash_header(struct tcp_sigpool *hp, return err; } +int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash, + struct tcp_ao_key *key, const u8 *tkey, + const union tcp_ao_addr *daddr, + const union tcp_ao_addr *saddr, + const struct tcphdr *th, u32 sne) +{ + int tkey_len = tcp_ao_digest_size(key); + int hash_offset = ao_hash - (char *)th; + struct tcp_sigpool hp; + void *hash_buf = NULL; + + hash_buf = kmalloc(tkey_len, GFP_ATOMIC); + if (!hash_buf) + goto clear_hash_noput; + + if (tcp_sigpool_start(key->tcp_sigpool_id, &hp)) + goto clear_hash_noput; + + if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len)) + goto clear_hash; + + if (crypto_ahash_init(hp.req)) + goto clear_hash; + + if (tcp_ao_hash_sne(&hp, sne)) + goto clear_hash; + if (family == AF_INET) { + if (tcp_v4_ao_hash_pseudoheader(&hp, daddr->a4.s_addr, + saddr->a4.s_addr, th->doff * 4)) + goto clear_hash; +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + if (tcp_v6_ao_hash_pseudoheader(&hp, &daddr->a6, + &saddr->a6, th->doff * 4)) + goto clear_hash; +#endif + } else { + WARN_ON_ONCE(1); + goto clear_hash; + } + if (tcp_ao_hash_header(&hp, th, false, + ao_hash, hash_offset, tcp_ao_maclen(key))) + goto clear_hash; + ahash_request_set_crypt(hp.req, NULL, hash_buf, 0); + if (crypto_ahash_final(hp.req)) + goto clear_hash; + + memcpy(ao_hash, hash_buf, tcp_ao_maclen(key)); + tcp_sigpool_end(&hp); + kfree(hash_buf); + return 0; + +clear_hash: + tcp_sigpool_end(&hp); +clear_hash_noput: + memset(ao_hash, 0, tcp_ao_maclen(key)); + kfree(hash_buf); + return 1; +} + int tcp_ao_hash_skb(unsigned short int family, char *ao_hash, struct tcp_ao_key *key, const struct sock *sk, const struct sk_buff *skb, @@ -437,6 +497,47 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0); } +int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, + const struct tcp_ao_hdr *aoh, int l3index, u32 seq, + struct tcp_ao_key **key, char **traffic_key, + bool *allocated_traffic_key, u8 *keyid, u32 *sne) +{ + const struct tcphdr *th = tcp_hdr(skb); + struct tcp_ao_info *ao_info; + + *allocated_traffic_key = false; + /* If there's no socket - than initial sisn/disn are unknown. + * Drop the segment. RFC5925 (7.7) advises to require graceful + * restart [RFC4724]. Alternatively, the RFC5925 advises to + * save/restore traffic keys before/after reboot. + * Linux TCP-AO support provides TCP_AO_ADD_KEY and TCP_AO_REPAIR + * options to restore a socket post-reboot. + */ + if (!sk) + return -ENOTCONN; + + if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) { + return -1; + } else { + struct tcp_ao_key *rnext_key; + + if (sk->sk_state == TCP_TIME_WAIT) + return -1; + ao_info = rcu_dereference(tcp_sk(sk)->ao_info); + if (!ao_info) + return -ENOENT; + + *key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1); + if (!*key) + return -ENOENT; + *traffic_key = snd_other_key(*key); + rnext_key = READ_ONCE(ao_info->rnext_key); + *keyid = rnext_key->rcvid; + *sne = 0; + } + return 0; +} + static int tcp_ao_cache_traffic_keys(const struct sock *sk, struct tcp_ao_info *ao, struct tcp_ao_key *ao_key) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 0e9c6cfd4ab2..ee14a2405801 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -657,6 +657,52 @@ void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(tcp_v4_send_check); +#define REPLY_OPTIONS_LEN (MAX_TCP_OPTION_SPACE / sizeof(__be32)) + +static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb, + const struct tcp_ao_hdr *aoh, + struct ip_reply_arg *arg, struct tcphdr *reply, + __be32 reply_options[REPLY_OPTIONS_LEN]) +{ +#ifdef CONFIG_TCP_AO + int sdif = tcp_v4_sdif(skb); + int dif = inet_iif(skb); + int l3index = sdif ? dif : 0; + bool allocated_traffic_key; + struct tcp_ao_key *key; + char *traffic_key; + bool drop = true; + u32 ao_sne = 0; + u8 keyid; + + rcu_read_lock(); + if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, reply->seq, + &key, &traffic_key, &allocated_traffic_key, + &keyid, &ao_sne)) + goto out; + + reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) | + (aoh->rnext_keyid << 8) | keyid); + arg->iov[0].iov_len += round_up(tcp_ao_len(key), 4); + reply->doff = arg->iov[0].iov_len / 4; + + if (tcp_ao_hash_hdr(AF_INET, (char *)&reply_options[1], + key, traffic_key, + (union tcp_ao_addr *)&ip_hdr(skb)->saddr, + (union tcp_ao_addr *)&ip_hdr(skb)->daddr, + reply, ao_sne)) + goto out; + drop = false; +out: + rcu_read_unlock(); + if (allocated_traffic_key) + kfree(traffic_key); + return drop; +#else + return true; +#endif +} + /* * This routine will send an RST to the other tcp. * @@ -670,28 +716,21 @@ EXPORT_SYMBOL(tcp_v4_send_check); * Exception: precedence violation. We do not implement it in any case. */ -#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) -#endif - static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) { const struct tcphdr *th = tcp_hdr(skb); struct { struct tcphdr th; - __be32 opt[OPTION_BYTES / sizeof(__be32)]; + __be32 opt[REPLY_OPTIONS_LEN]; } rep; + const __u8 *md5_hash_location = NULL; + const struct tcp_ao_hdr *aoh; struct ip_reply_arg arg; #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *key = NULL; - const __u8 *md5_hash_location = NULL; unsigned char newhash[16]; - int genhash; struct sock *sk1 = NULL; + int genhash; #endif u64 transmit_time = 0; struct sock *ctl_sk; @@ -728,11 +767,15 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) arg.iov[0].iov_len = sizeof(rep.th); 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)) + if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, &aoh)) return; + if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, &arg, &rep.th, rep.opt)) + return; + +#ifdef CONFIG_TCP_MD5SIG rcu_read_lock(); if (sk && sk_fullsock(sk)) { const union tcp_md5_addr *addr; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 4c645160362e..bc4ef00621b4 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -854,7 +854,9 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, struct tcp_md5sig_key *key, int rst, - u8 tclass, __be32 label, u32 priority, u32 txhash) + u8 tclass, __be32 label, u32 priority, u32 txhash, + struct tcp_ao_key *ao_key, char *tkey, + u8 rcv_next, u32 ao_sne) { const struct tcphdr *th = tcp_hdr(skb); struct tcphdr *t1; @@ -873,6 +875,13 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 if (key) tot_len += TCPOLEN_MD5SIG_ALIGNED; #endif +#ifdef CONFIG_TCP_AO + if (ao_key) + tot_len += tcp_ao_len(ao_key); +#endif +#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO) + WARN_ON_ONCE(key && ao_key); +#endif #ifdef CONFIG_MPTCP if (rst && !key) { @@ -924,6 +933,17 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 &ipv6_hdr(skb)->daddr, t1); } #endif +#ifdef CONFIG_TCP_AO + if (ao_key) { + *topt++ = htonl((TCPOPT_AO << 24) | (tcp_ao_len(ao_key) << 16) | + (ao_key->sndid << 8) | (rcv_next)); + + tcp_ao_hash_hdr(AF_INET6, (char *)topt, ao_key, tkey, + (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr, + (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr, + t1, ao_sne); + } +#endif memset(&fl6, 0, sizeof(fl6)); fl6.daddr = ipv6_hdr(skb)->saddr; @@ -988,17 +1008,23 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) struct ipv6hdr *ipv6h = ipv6_hdr(skb); u32 seq = 0, ack_seq = 0; struct tcp_md5sig_key *key = NULL; -#ifdef CONFIG_TCP_MD5SIG + __be32 label = 0; + u32 priority = 0; + struct net *net; + struct tcp_ao_key *ao_key = NULL; + u8 rcv_next = 0; + u32 ao_sne = 0; + u32 txhash = 0; + int oif = 0; const __u8 *md5_hash_location = NULL; + const struct tcp_ao_hdr *aoh; + char *traffic_key = NULL; + bool allocated_traffic_key = false; +#ifdef CONFIG_TCP_MD5SIG unsigned char newhash[16]; int genhash; struct sock *sk1 = NULL; #endif - __be32 label = 0; - u32 priority = 0; - struct net *net; - u32 txhash = 0; - int oif = 0; if (th->rst) return; @@ -1010,12 +1036,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) return; 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)) + if (tcp_parse_auth_options(th, &md5_hash_location, &aoh)) return; - rcu_read_lock(); +#ifdef CONFIG_TCP_MD5SIG if (sk && sk_fullsock(sk)) { int l3index; @@ -1064,6 +1089,18 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - (th->doff << 2); +#ifdef CONFIG_TCP_AO + if (aoh) { + int l3index; + + l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; + if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq, &ao_key, + &traffic_key, &allocated_traffic_key, + &rcv_next, &ao_sne)) + goto out; + } +#endif + if (sk) { oif = sk->sk_bound_dev_if; if (sk_fullsock(sk)) { @@ -1086,10 +1123,13 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) } tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, - ipv6_get_dsfield(ipv6h), label, priority, txhash); + ipv6_get_dsfield(ipv6h), label, priority, txhash, + ao_key, traffic_key, rcv_next, ao_sne); -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) out: + if (allocated_traffic_key) + kfree(traffic_key); rcu_read_unlock(); #endif } @@ -1100,7 +1140,7 @@ static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, __be32 label, u32 priority, u32 txhash) { tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0, - tclass, label, priority, txhash); + tclass, label, priority, txhash, NULL, NULL, 0, 0); } static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)

[v8.1,net-next,08/23] net/tcp: Add AO sign to RST packets

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