[v5,08/21] net/tcp: Add AO sign to RST packets

Message ID	20230403213420.1576559-9-dima@arista.com (mailing list archive)
State	Changes Requested
Delegated to:	Netdev Maintainers
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Dmitry Safonov <dima@arista.com> To: linux-kernel@vger.kernel.org, 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: 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>, Eric Biggers <ebiggers@kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, Francesco Ruggeri <fruggeri05@gmail.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>, netdev@vger.kernel.org, Francesco Ruggeri <fruggeri@arista.com> Subject: [PATCH v5 08/21] net/tcp: Add AO sign to RST packets Date: Mon, 3 Apr 2023 22:34:07 +0100 Message-Id: <20230403213420.1576559-9-dima@arista.com> In-Reply-To: <20230403213420.1576559-1-dima@arista.com> References: <20230403213420.1576559-1-dima@arista.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	net/tcp: Add TCP-AO support \| expand [v5,00/21] net/tcp: Add TCP-AO support [v5,01/21,draft] net/tcp: Prepare tcp_md5sig_pool for TCP-AO [v5,02/21] net/tcp: Add TCP-AO config and structures [v5,03/21] net/tcp: Introduce TCP_AO setsockopt()s [v5,04/21] net/tcp: Prevent TCP-MD5 with TCP-AO being set [v5,05/21] net/tcp: Calculate TCP-AO traffic keys [v5,06/21] net/tcp: Add TCP-AO sign to outgoing packets [v5,07/21] net/tcp: Add tcp_parse_auth_options() [v5,08/21] net/tcp: Add AO sign to RST packets [v5,09/21] net/tcp: Add TCP-AO sign to twsk [v5,10/21] net/tcp: Wire TCP-AO to request sockets [v5,11/21] net/tcp: Sign SYN-ACK segments with TCP-AO [v5,12/21] net/tcp: Verify inbound TCP-AO signed segments [v5,13/21] net/tcp: Add TCP-AO segments counters [v5,14/21] net/tcp: Add TCP-AO SNE support [v5,15/21] net/tcp: Add tcp_hash_fail() ratelimited logs [v5,16/21] net/tcp: Ignore specific ICMPs for TCP-AO connections [v5,17/21] net/tcp: Add option for TCP-AO to (not) hash header [v5,18/21] net/tcp: Add TCP-AO getsockopt()s [v5,19/21] net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs) [v5,20/21] net/tcp-ao: Add static_key for TCP-AO [v5,21/21] net/tcp-ao: Wire up l3index to TCP-AO

Context	Check	Description
netdev/tree_selection	success	Guessing tree name failed - patch did not apply, async

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index 72fc87cf58bf..5b85ecd7024a 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -121,6 +121,8 @@ 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); void tcp_ao_destroy_sock(struct sock *sk); @@ -128,6 +130,12 @@ u32 tcp_ao_compute_sne(u32 sne, u32 seq, u32 new_seq); 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); + /* 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 56cebdfd07b8..ddd28bf80511 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -56,8 +56,8 @@ 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; @@ -70,6 +70,7 @@ static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, return NULL; } +EXPORT_SYMBOL_GPL(tcp_ao_established_key); static inline int ipv4_prefix_cmp(const struct in_addr *addr1, const struct in_addr *addr2, @@ -387,6 +388,61 @@ 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) +{ + __u8 tmp_hash[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align; + int tkey_len = tcp_ao_digest_size(key); + int hash_offset = ao_hash - (char *)th; + struct tcp_sigpool hp; + + 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, tmp_hash, 0); + if (crypto_ahash_final(hp.req)) + goto clear_hash; + + memcpy(ao_hash, tmp_hash, tcp_ao_maclen(key)); + tcp_sigpool_end(); + return 0; + +clear_hash: + tcp_sigpool_end(); +clear_hash_noput: + memset(ao_hash, 0, tcp_ao_maclen(key)); + return 1; +} +EXPORT_SYMBOL_GPL(tcp_ao_hash_hdr); + 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, diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 3ffc966868e0..f86f261dec41 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -684,16 +684,19 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) __be32 opt[OPTION_BYTES / sizeof(__be32)]; } rep; struct ip_reply_arg arg; + u64 transmit_time = 0; + struct sock *ctl_sk; + struct net *net; +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) + const __u8 *md5_hash_location = NULL; + const struct tcp_ao_hdr *aoh; #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 #endif - u64 transmit_time = 0; - struct sock *ctl_sk; - struct net *net; /* Never send a reset in response to a reset. */ if (th->rst) @@ -725,12 +728,14 @@ 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 +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) /* 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; rcu_read_lock(); +#endif +#ifdef CONFIG_TCP_MD5SIG if (sk && sk_fullsock(sk)) { const union tcp_md5_addr *addr; int l3index; @@ -791,6 +796,63 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) key, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &rep.th); } +#endif +#ifdef CONFIG_TCP_AO + /* if (!sk || sk->sk_state == TCP_LISTEN) then the initial sisn/disn + * are unknown. Skip TCP-AO signing. + * Contrary to TCP-MD5 unsigned RST will be sent if there was AO sign + * in segment, but TCP-AO signing isn't possible for reply. + */ + if (sk && aoh && sk->sk_state != TCP_LISTEN) { + char traffic_key[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align; + struct tcp_ao_key *ao_key, *rnext_key; + struct tcp_ao_info *ao_info; + u32 ao_sne; + u8 keyid; + + /* TODO: reqsk support */ + if (sk->sk_state == TCP_NEW_SYN_RECV) + goto skip_ao_sign; + + ao_info = rcu_dereference(tcp_sk(sk)->ao_info); + + if (!ao_info) + goto skip_ao_sign; + + ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1); + if (!ao_key) + goto skip_ao_sign; + + /* XXX: optimize by using cached traffic key depending + * on socket state + */ + if (tcp_v4_ao_calc_key_sk(ao_key, traffic_key, sk, + ao_info->lisn, ao_info->risn, true)) + goto out; + + /* rcv_next holds the rcv_next of the peer, make keyid + * hold our rcv_next + */ + rnext_key = ao_info->rnext_key; + keyid = rnext_key->rcvid; + ao_sne = tcp_ao_compute_sne(ao_info->snd_sne, + ao_info->snd_sne_seq, + ntohl(rep.th.seq)); + + rep.opt[0] = htonl((TCPOPT_AO << 24) | + (tcp_ao_len(ao_key) << 16) | + (aoh->rnext_keyid << 8) | keyid); + arg.iov[0].iov_len += round_up(tcp_ao_len(ao_key), 4); + rep.th.doff = arg.iov[0].iov_len / 4; + + if (tcp_ao_hash_hdr(AF_INET, (char *)&rep.opt[1], + ao_key, traffic_key, + (union tcp_ao_addr *)&ip_hdr(skb)->saddr, + (union tcp_ao_addr *)&ip_hdr(skb)->daddr, + &rep.th, ao_sne)) + goto out; + } +skip_ao_sign: #endif /* Can't co-exist with TCPMD5, hence check rep.opt[0] */ if (rep.opt[0] == 0) { @@ -848,7 +910,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); local_bh_enable(); -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) out: rcu_read_unlock(); #endif diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 519fce8c21f3..6930044fb5a2 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -857,7 +857,9 @@ 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; @@ -876,6 +878,13 @@ 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) { @@ -927,6 +936,21 @@ 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)); + + /* TODO: this is right now not going to work for listening + * sockets since the socket won't have the needed ipv6 + * addresses + */ + 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; @@ -991,17 +1015,28 @@ 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 - const __u8 *md5_hash_location = NULL; - unsigned char newhash[16]; - int genhash; - struct sock *sk1 = NULL; -#endif __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; +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) + const __u8 *md5_hash_location = NULL; + const struct tcp_ao_hdr *aoh; +#endif +#ifdef CONFIG_TCP_MD5SIG + unsigned char newhash[16]; + int genhash; + struct sock *sk1 = NULL; +#endif +#ifdef CONFIG_TCP_AO + char traffic_key[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align; +#else + u8 *traffic_key = NULL; +#endif if (th->rst) return; @@ -1013,12 +1048,13 @@ 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 +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) /* 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(); +#endif +#ifdef CONFIG_TCP_MD5SIG if (sk && sk_fullsock(sk)) { int l3index; @@ -1067,6 +1103,45 @@ 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 (!sk || sk->sk_state == TCP_LISTEN) then the initial sisn/disn + * are unknown. Skip TCP-AO signing. + * Contrary to TCP-MD5 unsigned RST will be sent if there was AO sign + * in segment, but TCP-AO signing isn't possible for reply. + */ + if (sk && aoh && sk->sk_state != TCP_LISTEN) { + struct tcp_ao_info *ao_info; + struct tcp_ao_key *rnext_key; + + /* TODO: reqsk support */ + if (sk->sk_state == TCP_NEW_SYN_RECV) + goto skip_ao_sign; + + ao_info = rcu_dereference(tcp_sk(sk)->ao_info); + if (!ao_info) + goto skip_ao_sign; + + /* rcv_next is the peer's here */ + ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1); + if (!ao_key) + goto skip_ao_sign; + + /* XXX: optimize by using cached traffic key depending + * on socket state + */ + if (tcp_v6_ao_calc_key_sk(ao_key, traffic_key, sk, + ao_info->lisn, ao_info->risn, true)) + goto out; + + /* rcv_next switches to our rcv_next */ + rnext_key = READ_ONCE(ao_info->rnext_key); + rcv_next = rnext_key->rcvid; + ao_sne = tcp_ao_compute_sne(ao_info->snd_sne, + ao_info->snd_sne_seq, seq); + } +skip_ao_sign: +#endif + if (sk) { oif = sk->sk_bound_dev_if; if (sk_fullsock(sk)) { @@ -1089,9 +1164,10 @@ 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: rcu_read_unlock(); #endif @@ -1103,7 +1179,7 @@ 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)

[v5,08/21] net/tcp: Add AO sign to RST packets

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