[PATCH v14 net-next 10/23] net/tcp: Wire TCP-AO to request sockets

From: Dmitry Safonov
Date: Mon Oct 09 2023 - 19:08:34 EST

Now when the new request socket is created from the listening socket,
it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is
a new helper for checking if TCP-AO option was used to create the
request socket.
tcp_ao_copy_all_matching() will copy all keys that match the peer on the
request socket, as well as preparing them for the usage (creating
traffic keys).

Co-developed-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx>
Signed-off-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx>
Co-developed-by: Salam Noureddine <noureddine@xxxxxxxxxx>
Signed-off-by: Salam Noureddine <noureddine@xxxxxxxxxx>
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
Acked-by: David Ahern <dsahern@xxxxxxxxxx>
---
include/linux/tcp.h | 18 +++
include/net/tcp.h | 6 +
include/net/tcp_ao.h | 24 ++++
net/ipv4/syncookies.c | 2 +
net/ipv4/tcp_ao.c | 237 ++++++++++++++++++++++++++++++++++++++-
net/ipv4/tcp_input.c | 15 +++
net/ipv4/tcp_ipv4.c | 66 +++++++++--
net/ipv4/tcp_minisocks.c | 10 ++
net/ipv4/tcp_output.c | 37 +++---
net/ipv6/syncookies.c | 2 +
net/ipv6/tcp_ao.c | 38 ++++++-
net/ipv6/tcp_ipv6.c | 73 ++++++++++--
12 files changed, 491 insertions(+), 37 deletions(-)

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 51458219be4e..1d9b8e04a4ee 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -165,6 +165,11 @@ struct tcp_request_sock {
* after data-in-SYN.
*/
u8 syn_tos;
+#ifdef CONFIG_TCP_AO
+ u8 ao_keyid;
+ u8 ao_rcv_next;
+ u8 maclen;
+#endif
};

static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
@@ -172,6 +177,19 @@ static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
return (struct tcp_request_sock *)req;
}

+static inline bool tcp_rsk_used_ao(const struct request_sock *req)
+{
+ /* The real length of MAC is saved in the request socket,
+ * signing anything with zero-length makes no sense, so here is
+ * a little hack..
+ */
+#ifndef CONFIG_TCP_AO
+ return false;
+#else
+ return tcp_rsk(req)->maclen != 0;
+#endif
+}
+
#define TCP_RMEM_TO_WIN_SCALE 8

struct tcp_sock {
diff --git a/include/net/tcp.h b/include/net/tcp.h
index dc74908ffa5a..13657b70d5d7 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2178,6 +2178,12 @@ struct tcp_request_sock_ops {
const struct sock *sk,
const struct sk_buff *skb);
#endif
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
+ int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk);
+#endif
#ifdef CONFIG_SYN_COOKIES
__u32 (*cookie_init_seq)(const struct sk_buff *skb,
__u16 *mss);
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index af2caf7e76fc..d04b17971c3c 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -123,6 +123,9 @@ 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_copy_all_matching(const struct sock *sk, struct sock *newsk,
+ struct request_sock *req, struct sk_buff *skb,
+ int family);
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, bool twsk);
@@ -147,6 +150,11 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
+int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req);
+struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne);
@@ -154,11 +162,21 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes);
+int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb, __be32 sisn, __be32 disn);
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
+int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req);
+struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int sndid, int rcvid);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk, int sndid, int rcvid);
+struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne);
@@ -178,6 +196,12 @@ static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
return 0;
}

+static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+ struct tcp_request_sock *treq,
+ unsigned short int family)
+{
+}
+
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)
{
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index dc478a0574cb..23fca22bc992 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -394,6 +394,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
treq->snt_synack = 0;
treq->tfo_listener = false;

+ tcp_ao_syncookie(sk, skb, treq, AF_INET);
+
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;

diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 00d21f6242de..c8006b0cbb8a 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -169,6 +169,23 @@ static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
hlist_add_head_rcu(&mkt->node, &ao->head);
}

+static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
+ struct tcp_ao_key *key)
+{
+ struct tcp_ao_key *new_key;
+
+ new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
+ GFP_ATOMIC);
+ if (!new_key)
+ return NULL;
+
+ *new_key = *key;
+ INIT_HLIST_NODE(&new_key->node);
+ tcp_sigpool_get(new_key->tcp_sigpool_id);
+
+ return new_key;
+}
+
static void tcp_ao_key_free_rcu(struct rcu_head *head)
{
struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
@@ -290,6 +307,42 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
return -EOPNOTSUPP;
}

+int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+ return tcp_v4_ao_calc_key(mkt, key,
+ ireq->ir_loc_addr, ireq->ir_rmt_addr,
+ htons(ireq->ir_num), ireq->ir_rmt_port,
+ htonl(tcp_rsk(req)->snt_isn),
+ htonl(tcp_rsk(req)->rcv_isn));
+}
+
+static int tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb,
+ __be32 sisn, __be32 disn)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ return tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr,
+ th->source, th->dest, sisn, disn);
+}
+
+static int tcp_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb,
+ __be32 sisn, __be32 disn, int family)
+{
+ if (family == AF_INET)
+ return tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (family == AF_INET6)
+ return tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#endif
+ return -EAFNOSUPPORT;
+}
+
static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
__be32 daddr, __be32 saddr,
int nbytes)
@@ -515,6 +568,16 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
tkey, hash_offset, sne);
}

+struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid)
+{
+ union tcp_ao_addr *addr =
+ (union tcp_ao_addr *)&inet_rsk(req)->ir_rmt_addr;
+
+ return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid);
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -528,6 +591,7 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
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;
@@ -542,7 +606,44 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
return -ENOTCONN;

if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
- return -1;
+ union tcp_ao_addr *addr;
+ unsigned int family = READ_ONCE(sk->sk_family);
+ __be32 disn, sisn;
+
+ if (sk->sk_state == TCP_NEW_SYN_RECV) {
+ struct request_sock *req = inet_reqsk(sk);
+
+ sisn = htonl(tcp_rsk(req)->rcv_isn);
+ disn = htonl(tcp_rsk(req)->snt_isn);
+ *sne = 0;
+ } else {
+ sisn = th->seq;
+ disn = 0;
+ }
+ if (IS_ENABLED(CONFIG_IPV6) && sk->sk_family == AF_INET6)
+ addr = (union tcp_md5_addr *)&ipv6_hdr(skb)->saddr;
+ else
+ addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (family == AF_INET6 && ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+ family = AF_INET;
+#endif
+
+ sk = sk_const_to_full_sk(sk);
+ ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!ao_info)
+ return -ENOENT;
+ *key = tcp_ao_do_lookup(sk, addr, family, -1, aoh->rnext_keyid);
+ if (!*key)
+ return -ENOENT;
+ *traffic_key = kmalloc(tcp_ao_digest_size(*key), GFP_ATOMIC);
+ if (!*traffic_key)
+ return -ENOMEM;
+ *allocated_traffic_key = true;
+ if (tcp_ao_calc_key_skb(*key, *traffic_key, skb,
+ sisn, disn, family))
+ return -1;
+ *keyid = (*key)->rcvid;
} else {
struct tcp_ao_key *rnext_key;

@@ -598,6 +699,46 @@ int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
return 0;
}

+static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,
+ const struct sock *sk, const struct sk_buff *skb,
+ int sndid, int rcvid)
+{
+ if (family == AF_INET) {
+ const struct iphdr *iph = ip_hdr(skb);
+
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
+ AF_INET, sndid, rcvid);
+ } else {
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
+ AF_INET6, sndid, rcvid);
+ }
+}
+
+void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+ struct tcp_request_sock *treq,
+ unsigned short int family)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ const struct tcp_ao_hdr *aoh;
+ struct tcp_ao_key *key;
+
+ treq->maclen = 0;
+
+ if (tcp_parse_auth_options(th, NULL, &aoh) || !aoh)
+ return;
+
+ key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
+ if (!key)
+ /* Key not found, continue without TCP-AO */
+ return;
+
+ treq->ao_rcv_next = aoh->keyid;
+ treq->ao_keyid = aoh->rnext_keyid;
+ treq->maclen = tcp_ao_maclen(key);
+}
+
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
@@ -702,6 +843,100 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
tcp_ao_cache_traffic_keys(sk, ao, key);
}

+int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
+ struct request_sock *req, struct sk_buff *skb,
+ int family)
+{
+ struct tcp_ao_key *key, *new_key, *first_key;
+ struct tcp_ao_info *new_ao, *ao;
+ struct hlist_node *key_head;
+ union tcp_ao_addr *addr;
+ bool match = false;
+ int ret = -ENOMEM;
+
+ ao = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!ao)
+ return 0;
+
+ /* New socket without TCP-AO on it */
+ if (!tcp_rsk_used_ao(req))
+ return 0;
+
+ new_ao = tcp_ao_alloc_info(GFP_ATOMIC);
+ if (!new_ao)
+ return -ENOMEM;
+ new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
+ new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
+ new_ao->ao_required = ao->ao_required;
+
+ if (family == AF_INET) {
+ addr = (union tcp_ao_addr *)&newsk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (family == AF_INET6) {
+ addr = (union tcp_ao_addr *)&newsk->sk_v6_daddr;
+#endif
+ } else {
+ ret = -EAFNOSUPPORT;
+ goto free_ao;
+ }
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ if (tcp_ao_key_cmp(key, addr, key->prefixlen, family, -1, -1))
+ continue;
+
+ new_key = tcp_ao_copy_key(newsk, key);
+ if (!new_key)
+ goto free_and_exit;
+
+ tcp_ao_cache_traffic_keys(newsk, new_ao, new_key);
+ tcp_ao_link_mkt(new_ao, new_key);
+ match = true;
+ }
+
+ if (!match) {
+ /* RFC5925 (7.4.1) specifies that the TCP-AO status
+ * of a connection is determined on the initial SYN.
+ * At this point the connection was TCP-AO enabled, so
+ * it can't switch to being unsigned if peer's key
+ * disappears on the listening socket.
+ */
+ ret = -EKEYREJECTED;
+ goto free_and_exit;
+ }
+
+ key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
+ first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
+
+ key = tcp_ao_established_key(new_ao, tcp_rsk(req)->ao_keyid, -1);
+ if (key)
+ new_ao->current_key = key;
+ else
+ new_ao->current_key = first_key;
+
+ /* set rnext_key */
+ key = tcp_ao_established_key(new_ao, -1, tcp_rsk(req)->ao_rcv_next);
+ if (key)
+ new_ao->rnext_key = key;
+ else
+ new_ao->rnext_key = first_key;
+
+ sk_gso_disable(newsk);
+ rcu_assign_pointer(tcp_sk(newsk)->ao_info, new_ao);
+
+ return 0;
+
+free_and_exit:
+ hlist_for_each_entry_safe(key, key_head, &new_ao->head, node) {
+ hlist_del(&key->node);
+ tcp_sigpool_release(key->tcp_sigpool_id);
+ atomic_sub(tcp_ao_sizeof_key(key), &newsk->sk_omem_alloc);
+ kfree_sensitive(key);
+ }
+free_ao:
+ kfree(new_ao);
+ return ret;
+}
+
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5407ef0c1c04..520776714591 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -7016,6 +7016,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct flowi fl;
u8 syncookies;

+#ifdef CONFIG_TCP_AO
+ const struct tcp_ao_hdr *aoh;
+#endif
+
syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);

/* TW buckets are converted to open requests without
@@ -7101,6 +7105,17 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
inet_rsk(req)->ecn_ok = 0;
}

+#ifdef CONFIG_TCP_AO
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ goto drop_and_release; /* Invalid TCP options */
+ if (aoh) {
+ tcp_rsk(req)->maclen = aoh->length - sizeof(struct tcp_ao_hdr);
+ tcp_rsk(req)->ao_rcv_next = aoh->keyid;
+ tcp_rsk(req)->ao_keyid = aoh->rnext_keyid;
+ } else {
+ tcp_rsk(req)->maclen = 0;
+ }
+#endif
tcp_rsk(req)->snt_isn = isn;
tcp_rsk(req)->txhash = net_tx_rndhash();
tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index d98a943a4206..c332a86c22c5 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1071,13 +1071,47 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
tcp_sk(sk)->snd_nxt;

- /* RFC 7323 2.3
- * The window field (SEG.WND) of every outgoing segment, with the
- * exception of <SYN> segments, MUST be right-shifted by
- * Rcv.Wind.Shift bits:
- */
+#ifdef CONFIG_TCP_AO
+ if (tcp_rsk_used_ao(req)) {
+ const union tcp_md5_addr *addr;
+ const struct tcp_ao_hdr *aoh;
+
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+ if (!aoh)
+ return;
+
+ addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+ key.ao_key = tcp_ao_do_lookup(sk, addr, AF_INET,
+ aoh->rnext_keyid, -1);
+ if (unlikely(!key.ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ key.ao_key = tcp_ao_do_lookup(sk, addr, AF_INET, -1, -1);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!key.ao_key) {
+ net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n",
+ addr,
+ ntohs(tcp_hdr(skb)->source),
+ &ip_hdr(skb)->daddr,
+ ntohs(tcp_hdr(skb)->dest));
+ return;
+ }
+ }
+ key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
+ if (!key.traffic_key)
+ return;
+
+ key.type = TCP_KEY_AO;
+ key.rcv_next = aoh->keyid;
+ tcp_v4_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
+#else
+ if (0) {
+#endif
#ifdef CONFIG_TCP_MD5SIG
- if (static_branch_unlikely(&tcp_md5_needed.key)) {
+ } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
const union tcp_md5_addr *addr;
int l3index;

@@ -1086,8 +1120,14 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
if (key.md5_key)
key.type = TCP_KEY_MD5;
- }
#endif
+ }
+
+ /* RFC 7323 2.3
+ * The window field (SEG.WND) of every outgoing segment, with the
+ * exception of <SYN> segments, MUST be right-shifted by
+ * Rcv.Wind.Shift bits:
+ */
tcp_v4_send_ack(sk, skb, seq,
tcp_rsk(req)->rcv_nxt,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
@@ -1097,6 +1137,8 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos,
READ_ONCE(tcp_rsk(req)->txhash));
+ if (tcp_key_is_ao(&key))
+ kfree(key.traffic_key);
}

/*
@@ -1635,6 +1677,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
.req_md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
#endif
+#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v4_ao_lookup_rsk,
+ .ao_calc_key = tcp_v4_ao_calc_key_rsk,
+#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v4_init_sequence,
#endif
@@ -1736,12 +1782,16 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
/* Copy over the MD5 key from the original socket */
addr = (union tcp_md5_addr *)&newinet->inet_daddr;
key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
- if (key) {
+ if (key && !tcp_rsk_used_ao(req)) {
if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key))
goto put_and_exit;
sk_gso_disable(newsk);
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET))
+ goto put_and_exit; /* OOM, release back memory */
+#endif

if (__inet_inherit_port(sk, newsk) < 0)
goto put_and_exit;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index c60a84526733..a6ece0edf4d7 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -505,6 +505,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
const struct tcp_sock *oldtp;
struct tcp_sock *newtp;
u32 seq;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_key *ao_key;
+#endif

if (!newsk)
return NULL;
@@ -585,6 +588,13 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
#ifdef CONFIG_TCP_MD5SIG
newtp->md5sig_info = NULL; /*XXX*/
#endif
+#ifdef CONFIG_TCP_AO
+ newtp->ao_info = NULL;
+ ao_key = treq->af_specific->ao_lookup(sk, req,
+ tcp_rsk(req)->ao_keyid, -1);
+ if (ao_key)
+ newtp->tcp_header_len += tcp_ao_len(ao_key);
+ #endif
if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len)
newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;
newtp->rx_opt.mss_clamp = req->mss;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index edd3e8665c1b..4984e654be65 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -615,6 +615,7 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
* (but it may well be that other scenarios fail similarly).
*/
static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
+ const struct tcp_request_sock *tcprsk,
struct tcp_out_options *opts,
struct tcp_key *key)
{
@@ -629,20 +630,28 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
ptr += 4;
} else if (tcp_key_is_ao(key)) {
#ifdef CONFIG_TCP_AO
- struct tcp_ao_key *rnext_key;
- struct tcp_ao_info *ao_info;
- u8 maclen;
+ u8 maclen = tcp_ao_maclen(key->ao_key);

- ao_info = rcu_dereference_check(tp->ao_info,
+ if (tcprsk) {
+ u8 aolen = maclen + sizeof(struct tcp_ao_hdr);
+
+ *ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) |
+ (tcprsk->ao_keyid << 8) |
+ (tcprsk->ao_rcv_next));
+ } else {
+ struct tcp_ao_key *rnext_key;
+ struct tcp_ao_info *ao_info;
+
+ ao_info = rcu_dereference_check(tp->ao_info,
lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
- rnext_key = READ_ONCE(ao_info->rnext_key);
- if (WARN_ON_ONCE(!rnext_key))
- goto out_ao;
- maclen = tcp_ao_maclen(key->ao_key);
- *ptr++ = htonl((TCPOPT_AO << 24) |
- (tcp_ao_len(key->ao_key) << 16) |
- (key->ao_key->sndid << 8) |
- (rnext_key->rcvid));
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ if (WARN_ON_ONCE(!rnext_key))
+ goto out_ao;
+ *ptr++ = htonl((TCPOPT_AO << 24) |
+ (tcp_ao_len(key->ao_key) << 16) |
+ (key->ao_key->sndid << 8) |
+ (rnext_key->rcvid));
+ }
opts->hash_location = (__u8 *)ptr;
ptr += maclen / sizeof(*ptr);
if (unlikely(maclen % sizeof(*ptr))) {
@@ -1384,7 +1393,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->window = htons(min(tp->rcv_wnd, 65535U));
}

- tcp_options_write(th, tp, &opts, &key);
+ tcp_options_write(th, tp, NULL, &opts, &key);

if (tcp_key_is_md5(&key)) {
#ifdef CONFIG_TCP_MD5SIG
@@ -3729,7 +3738,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,

/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
- tcp_options_write(th, NULL, &opts, &key);
+ tcp_options_write(th, NULL, NULL, &opts, &key);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 5014aa663452..ad7a8caa7b2a 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -214,6 +214,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
treq->snt_isn = cookie;
treq->ts_off = 0;
treq->txhash = net_tx_rndhash();
+ tcp_ao_syncookie(sk, skb, treq, AF_INET6);
+
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;

diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index d08735b6f3c5..c9a6fa84f6ce 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -49,6 +49,17 @@ static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
return err;
}

+int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb,
+ __be32 sisn, __be32 disn)
+{
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ return tcp_v6_ao_calc_key(mkt, key, &iph->saddr, &iph->daddr,
+ th->source, th->dest, sisn, disn);
+}
+
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send)
@@ -63,9 +74,21 @@ int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
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)
+int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+ return tcp_v6_ao_calc_key(mkt, key,
+ &ireq->ir_v6_loc_addr, &ireq->ir_v6_rmt_addr,
+ htons(ireq->ir_num), ireq->ir_rmt_port,
+ htonl(tcp_rsk(req)->snt_isn),
+ htonl(tcp_rsk(req)->rcv_isn));
+}
+
+struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int sndid, int rcvid)
{
return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6,
sndid, rcvid);
@@ -80,6 +103,15 @@ struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}

+struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid)
+{
+ struct in6_addr *addr = &inet_rsk(req)->ir_v6_rmt_addr;
+
+ return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+}
+
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7a871b774730..7d8dcbfe09ea 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -835,6 +835,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
.req_md5_lookup = tcp_v6_md5_lookup,
.calc_md5_hash = tcp_v6_md5_hash_skb,
#endif
+#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup_rsk,
+ .ao_calc_key = tcp_v6_ao_calc_key_rsk,
+#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v6_init_sequence,
#endif
@@ -1189,16 +1193,54 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
{
struct tcp_key key = {};

+#ifdef CONFIG_TCP_AO
+ if (tcp_rsk_used_ao(req)) {
+ const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
+ const struct tcp_ao_hdr *aoh;
+ int l3index;
+
+ l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+ if (!aoh)
+ return;
+ key.ao_key = tcp_v6_ao_do_lookup(sk, addr, aoh->rnext_keyid, -1);
+ if (unlikely(!key.ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ key.ao_key = tcp_v6_ao_do_lookup(sk, addr, -1, -1);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!key.ao_key) {
+ net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
+ addr,
+ ntohs(tcp_hdr(skb)->source),
+ &ipv6_hdr(skb)->daddr,
+ ntohs(tcp_hdr(skb)->dest));
+ return;
+ }
+ }
+ key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
+ if (!key.traffic_key)
+ return;
+
+ key.type = TCP_KEY_AO;
+ key.rcv_next = aoh->keyid;
+ tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
+#else
+ if (0) {
+#endif
#ifdef CONFIG_TCP_MD5SIG
- if (static_branch_unlikely(&tcp_md5_needed.key)) {
+ } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;

key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
l3index);
if (key.md5_key)
key.type = TCP_KEY_MD5;
- }
#endif
+ }

/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
@@ -1217,6 +1259,8 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
&key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
READ_ONCE(sk->sk_priority),
READ_ONCE(tcp_rsk(req)->txhash));
+ if (tcp_key_is_ao(&key))
+ kfree(key.traffic_key);
}


@@ -1446,19 +1490,26 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
#ifdef CONFIG_TCP_MD5SIG
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);

- /* Copy over the MD5 key from the original socket */
- key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
- if (key) {
- const union tcp_md5_addr *addr;
+ if (!tcp_rsk_used_ao(req)) {
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
+ if (key) {
+ const union tcp_md5_addr *addr;

- addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
- if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
- inet_csk_prepare_forced_close(newsk);
- tcp_done(newsk);
- goto out;
+ addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
+ if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
+ inet_csk_prepare_forced_close(newsk);
+ tcp_done(newsk);
+ goto out;
+ }
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ /* Copy over tcp_ao_info if any */
+ if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
+ goto out; /* OOM */
+#endif

if (__inet_inherit_port(sk, newsk) < 0) {
inet_csk_prepare_forced_close(newsk);
--
2.42.0