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Message-ID: <20231004223629.166300-6-dima@arista.com>
Date: Wed, 4 Oct 2023 23:36:09 +0100
From: Dmitry Safonov <dima@...sta.com>
To: David Ahern <dsahern@...nel.org>,
Eric Dumazet <edumazet@...gle.com>,
Paolo Abeni <pabeni@...hat.com>,
Jakub Kicinski <kuba@...nel.org>,
"David S. Miller" <davem@...emloft.net>
Cc: linux-kernel@...r.kernel.org,
Dmitry Safonov <dima@...sta.com>,
Andy Lutomirski <luto@...capital.net>,
Ard Biesheuvel <ardb@...nel.org>,
Bob Gilligan <gilligan@...sta.com>,
Dan Carpenter <error27@...il.com>,
David Laight <David.Laight@...lab.com>,
Dmitry Safonov <0x7f454c46@...il.com>,
Donald Cassidy <dcassidy@...hat.com>,
Eric Biggers <ebiggers@...nel.org>,
"Eric W. Biederman" <ebiederm@...ssion.com>,
Francesco Ruggeri <fruggeri05@...il.com>,
"Gaillardetz, Dominik" <dgaillar@...na.com>,
Herbert Xu <herbert@...dor.apana.org.au>,
Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
Ivan Delalande <colona@...sta.com>,
Leonard Crestez <cdleonard@...il.com>,
"Nassiri, Mohammad" <mnassiri@...na.com>,
Salam Noureddine <noureddine@...sta.com>,
Simon Horman <simon.horman@...igine.com>,
"Tetreault, Francois" <ftetreau@...na.com>,
netdev@...r.kernel.org
Subject: [PATCH v13 net-next 05/23] net/tcp: Calculate TCP-AO traffic keys
Add traffic key calculation the way it's described in RFC5926.
Wire it up to tcp_finish_connect() and cache the new keys straight away
on already established TCP connections.
Co-developed-by: Francesco Ruggeri <fruggeri@...sta.com>
Signed-off-by: Francesco Ruggeri <fruggeri@...sta.com>
Co-developed-by: Salam Noureddine <noureddine@...sta.com>
Signed-off-by: Salam Noureddine <noureddine@...sta.com>
Signed-off-by: Dmitry Safonov <dima@...sta.com>
Acked-by: David Ahern <dsahern@...nel.org>
---
include/net/tcp.h | 3 +
include/net/tcp_ao.h | 51 ++++++++++-
net/ipv4/tcp_ao.c | 203 ++++++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_input.c | 2 +
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_output.c | 2 +
net/ipv6/tcp_ao.c | 50 +++++++++++
net/ipv6/tcp_ipv6.c | 1 +
8 files changed, 311 insertions(+), 2 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 178c4c6d21a5..6e639c1bcb5d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2157,6 +2157,9 @@ struct tcp_sock_af_ops {
struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+ int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send);
#endif
};
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 3c7f576376f9..b021a811511b 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -89,8 +89,32 @@ struct tcp_ao_info {
};
#ifdef CONFIG_TCP_AO
+/* TCP-AO structures and functions */
+
+struct tcp4_ao_context {
+ __be32 saddr;
+ __be32 daddr;
+ __be16 sport;
+ __be16 dport;
+ __be32 sisn;
+ __be32 disn;
+};
+
+struct tcp6_ao_context {
+ struct in6_addr saddr;
+ struct in6_addr daddr;
+ __be16 sport;
+ __be16 dport;
+ __be32 sisn;
+ __be32 disn;
+};
+
+struct tcp_sigpool;
+
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
+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,
@@ -99,11 +123,22 @@ struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid);
+int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send);
/* ipv6 specific functions */
-int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen);
+int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk, __be32 sisn,
+ __be32 disn, bool send);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk, int sndid, int rcvid);
-#else
+int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen);
+void tcp_ao_established(struct sock *sk);
+void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
+void tcp_ao_connect_init(struct sock *sk);
+
+#else /* CONFIG_TCP_AO */
+
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr, int family, int sndid, int rcvid)
{
@@ -113,6 +148,18 @@ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
static inline void tcp_ao_destroy_sock(struct sock *sk)
{
}
+
+static inline void tcp_ao_established(struct sock *sk)
+{
+}
+
+static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
+{
+}
+
+static inline void tcp_ao_connect_init(struct sock *sk)
+{
+}
#endif
#endif /* _TCP_AO_H */
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index ee23356101f4..8e3aa82e649e 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -16,6 +16,34 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
+ unsigned int len, struct tcp_sigpool *hp)
+{
+ struct scatterlist sg;
+ int ret;
+
+ if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp->req),
+ mkt->key, mkt->keylen))
+ goto clear_hash;
+
+ ret = crypto_ahash_init(hp->req);
+ if (ret)
+ goto clear_hash;
+
+ sg_init_one(&sg, ctx, len);
+ ahash_request_set_crypt(hp->req, &sg, key, len);
+ crypto_ahash_update(hp->req);
+
+ ret = crypto_ahash_final(hp->req);
+ if (ret)
+ goto clear_hash;
+
+ return 0;
+clear_hash:
+ memset(key, 0, tcp_ao_digest_size(mkt));
+ return 1;
+}
+
/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
* it's known that the keys in ao_info are matching peer's
* family/address/VRF/etc.
@@ -169,6 +197,71 @@ void tcp_ao_destroy_sock(struct sock *sk)
kfree_rcu(ao, rcu);
}
+/* 4 tuple and ISNs are expected in NBO */
+static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+ __be32 saddr, __be32 daddr,
+ __be16 sport, __be16 dport,
+ __be32 sisn, __be32 disn)
+{
+ /* See RFC5926 3.1.1 */
+ struct kdf_input_block {
+ u8 counter;
+ u8 label[6];
+ struct tcp4_ao_context ctx;
+ __be16 outlen;
+ } __packed * tmp;
+ struct tcp_sigpool hp;
+ int err;
+
+ err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
+ if (err)
+ return err;
+
+ tmp = hp.scratch;
+ tmp->counter = 1;
+ memcpy(tmp->label, "TCP-AO", 6);
+ tmp->ctx.saddr = saddr;
+ tmp->ctx.daddr = daddr;
+ tmp->ctx.sport = sport;
+ tmp->ctx.dport = dport;
+ tmp->ctx.sisn = sisn;
+ tmp->ctx.disn = disn;
+ tmp->outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
+
+ err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
+ tcp_sigpool_end(&hp);
+
+ return err;
+}
+
+int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send)
+{
+ if (send)
+ return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr,
+ sk->sk_daddr, htons(sk->sk_num),
+ sk->sk_dport, sisn, disn);
+ else
+ return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr,
+ sk->sk_rcv_saddr, sk->sk_dport,
+ htons(sk->sk_num), disn, sisn);
+}
+
+static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send)
+{
+ if (mkt->family == AF_INET)
+ return tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (mkt->family == AF_INET6)
+ return tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#endif
+ else
+ return -EOPNOTSUPP;
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -177,6 +270,110 @@ 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);
}
+static int tcp_ao_cache_traffic_keys(const struct sock *sk,
+ struct tcp_ao_info *ao,
+ struct tcp_ao_key *ao_key)
+{
+ u8 *traffic_key = snd_other_key(ao_key);
+ int ret;
+
+ ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+ ao->lisn, ao->risn, true);
+ if (ret)
+ return ret;
+
+ traffic_key = rcv_other_key(ao_key);
+ ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+ ao->lisn, ao->risn, false);
+ return ret;
+}
+
+void tcp_ao_connect_init(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_ao_info *ao_info;
+ union tcp_ao_addr *addr;
+ struct tcp_ao_key *key;
+ int family;
+
+ ao_info = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao_info)
+ return;
+
+ /* Remove all keys that don't match the peer */
+ family = sk->sk_family;
+ if (family == AF_INET)
+ addr = (union tcp_ao_addr *)&sk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (family == AF_INET6)
+ addr = (union tcp_ao_addr *)&sk->sk_v6_daddr;
+#endif
+ else
+ return;
+
+ hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+ if (!tcp_ao_key_cmp(key, addr, key->prefixlen, family, -1, -1))
+ continue;
+
+ if (key == ao_info->current_key)
+ ao_info->current_key = NULL;
+ if (key == ao_info->rnext_key)
+ ao_info->rnext_key = NULL;
+ hlist_del_rcu(&key->node);
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+ }
+
+ key = tp->af_specific->ao_lookup(sk, sk, -1, -1);
+ if (key) {
+ /* if current_key or rnext_key were not provided,
+ * use the first key matching the peer
+ */
+ if (!ao_info->current_key)
+ ao_info->current_key = key;
+ if (!ao_info->rnext_key)
+ ao_info->rnext_key = key;
+ tp->tcp_header_len += tcp_ao_len(key);
+
+ ao_info->lisn = htonl(tp->write_seq);
+ } else {
+ /* TODO: probably, it should fail to connect() here */
+ rcu_assign_pointer(tp->ao_info, NULL);
+ kfree(ao_info);
+ }
+}
+
+void tcp_ao_established(struct sock *sk)
+{
+ struct tcp_ao_info *ao;
+ struct tcp_ao_key *key;
+
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao)
+ return;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node)
+ tcp_ao_cache_traffic_keys(sk, ao, key);
+}
+
+void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
+{
+ struct tcp_ao_info *ao;
+ struct tcp_ao_key *key;
+
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao)
+ return;
+
+ WRITE_ONCE(ao->risn, tcp_hdr(skb)->seq);
+
+ hlist_for_each_entry_rcu(key, &ao->head, node)
+ tcp_ao_cache_traffic_keys(sk, ao, key);
+}
+
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
@@ -558,6 +755,12 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
if (ret < 0)
goto err_free_sock;
+ /* Change this condition if we allow adding keys in states
+ * like close_wait, syn_sent or fin_wait...
+ */
+ if (sk->sk_state == TCP_ESTABLISHED)
+ tcp_ao_cache_traffic_keys(sk, ao_info, key);
+
tcp_ao_link_mkt(ao_info, key);
if (first) {
sk_gso_disable(sk);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 22c2a7c2e65e..d87ceb0cebed 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6109,6 +6109,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
+ tcp_ao_finish_connect(sk, skb);
tcp_set_state(sk, TCP_ESTABLISHED);
icsk->icsk_ack.lrcvtime = tcp_jiffies32;
@@ -6606,6 +6607,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
skb);
WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
}
+ tcp_ao_established(sk);
smp_mb();
tcp_set_state(sk, TCP_ESTABLISHED);
sk->sk_state_change(sk);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c92b92cbc3b8..b77cbe1047b3 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2286,6 +2286,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup,
.ao_parse = tcp_v4_parse_ao,
+ .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
#endif
};
#endif
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4aaca386611f..f1ebd930055c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3750,6 +3750,8 @@ static void tcp_connect_init(struct sock *sk)
if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps))
tp->tcp_header_len += TCPOLEN_TSTAMP_ALIGNED;
+ tcp_ao_connect_init(sk);
+
/* If user gave his TCP_MAXSEG, record it to clamp */
if (tp->rx_opt.user_mss)
tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 0640acaee67b..9ab594fadbd9 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -12,6 +12,56 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+ const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __be16 sport, __be16 dport,
+ __be32 sisn, __be32 disn)
+{
+ struct kdf_input_block {
+ u8 counter;
+ u8 label[6];
+ struct tcp6_ao_context ctx;
+ __be16 outlen;
+ } __packed * tmp;
+ struct tcp_sigpool hp;
+ int err;
+
+ err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
+ if (err)
+ return err;
+
+ tmp = hp.scratch;
+ tmp->counter = 1;
+ memcpy(tmp->label, "TCP-AO", 6);
+ tmp->ctx.saddr = *saddr;
+ tmp->ctx.daddr = *daddr;
+ tmp->ctx.sport = sport;
+ tmp->ctx.dport = dport;
+ tmp->ctx.sisn = sisn;
+ tmp->ctx.disn = disn;
+ tmp->outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
+
+ err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
+ tcp_sigpool_end(&hp);
+
+ return err;
+}
+
+int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk, __be32 sisn,
+ __be32 disn, bool send)
+{
+ if (send)
+ return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_rcv_saddr,
+ &sk->sk_v6_daddr, htons(sk->sk_num),
+ sk->sk_dport, sisn, disn);
+ else
+ return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_daddr,
+ &sk->sk_v6_rcv_saddr, sk->sk_dport,
+ htons(sk->sk_num), disn, sisn);
+}
+
static struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 78980d3520b0..4487cd172056 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1917,6 +1917,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
+ .ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
#endif
};
#endif
--
2.42.0
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