[PATCH 15/31] net/tcp: Wire TCP-AO to request sockets

Dmitry Safonov
2022-08-18T17:03:09Z

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@arista.com>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Co-developed-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
include/linux/tcp.h | 18 +++++
include/net/tcp.h | 7 ++
include/net/tcp_ao.h | 16 +++++
net/ipv4/tcp_ao.c | 137 +++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_input.c | 19 +++++-
net/ipv4/tcp_ipv4.c | 63 ++++++++++++++++--
net/ipv4/tcp_minisocks.c | 10 +++
net/ipv4/tcp_output.c | 13 +++-
net/ipv6/tcp_ao.c | 21 ++++++
net/ipv6/tcp_ipv6.c | 78 ++++++++++++++++++----
10 files changed, 361 insertions(+), 21 deletions(-)

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 8031995b58a2..0e0f07d12f7b 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
+}
+
struct tcp_sock {
/* inet_connection_sock has to be the first member of tcp_sock */
struct inet_connection_sock inet_conn;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 061fe8471bfc..f21898bb31bd 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2103,6 +2103,13 @@ 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 af82b4aeef11..a1d26e1a0b82 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -119,6 +119,9 @@ int tcp_ao_hash_skb(unsigned short int family,
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_ao_do_lookup_sndid(const struct sock *sk, u8 keyid);
+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);
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
@@ -142,6 +145,11 @@ 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);
@@ -152,9 +160,17 @@ int tcp_v6_ao_hash_pseudoheader(struct crypto_pool_ahash *hp,
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);
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 528b6650c72c..a797eedfbcdf 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -52,6 +52,21 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
return 1;
}

+struct tcp_ao_key *tcp_ao_do_lookup_keyid(struct tcp_ao_info *ao,
+ int sndid, int rcvid)
+{
+ struct tcp_ao_key *key;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ if ((sndid >= 0 && key->sndid != sndid) ||
+ (rcvid >= 0 && key->rcvid != rcvid))
+ continue;
+ return key;
+ }
+
+ return NULL;
+}
+
struct tcp_ao_key *tcp_ao_do_lookup_rcvid(struct sock *sk, u8 keyid)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -189,6 +204,22 @@ void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
hlist_add_head_rcu(&mkt->node, &ao->head);
}

+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);
+ crypto_pool_add(new_key->crypto_pool_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);
@@ -286,6 +317,18 @@ int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
htons(sk->sk_num), disn, sisn);
}

+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_hash_pseudoheader(struct crypto_pool_ahash *hp,
__be32 daddr, __be32 saddr,
int nbytes)
@@ -543,6 +586,16 @@ 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, 0);
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -644,6 +697,90 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
}
}

+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_info *ao;
+ struct tcp_ao_info *new_ao;
+ struct tcp_ao_key *key, *new_key, *first_key;
+ struct hlist_node *n;
+ union tcp_ao_addr *addr;
+ bool match = false;
+
+ 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, ao);
+ if (!new_ao)
+ return -ENOMEM;
+ new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
+ new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
+
+ if (family == AF_INET)
+ addr = (union tcp_ao_addr *)&newsk->sk_daddr;
+ else
+ addr = (union tcp_ao_addr *)&newsk->sk_v6_daddr;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ if (tcp_ao_key_cmp(key, addr, key->prefixlen, family,
+ -1, -1, 0))
+ 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) {
+ struct hlist_node *key_head;
+
+ key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
+ first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
+
+ /* set current_key */
+ key = tcp_ao_do_lookup_keyid(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_do_lookup_keyid(new_ao, -1, tcp_rsk(req)->ao_rcv_next);
+ if (key)
+ new_ao->rnext_key = key;
+ else
+ new_ao->rnext_key = first_key;
+
+ new_ao->snd_sne_seq = tcp_rsk(req)->snt_isn;
+ new_ao->rcv_sne_seq = tcp_rsk(req)->rcv_isn;
+
+ 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, n, &new_ao->head, node) {
+ hlist_del(&key->node);
+ crypto_pool_release(key->crypto_pool_id);
+ atomic_sub(tcp_ao_sizeof_key(key), &newsk->sk_omem_alloc);
+ kfree(key);
+ }
+ kfree(new_ao);
+ return -ENOMEM;
+}
+
static int tcp_ao_current_rnext(struct sock *sk, u16 tcpa_flags,
u8 tcpa_sndid, u8 tcpa_rcvid)
{
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 27e95876cba1..b8175ded8a70 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6921,6 +6921,14 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct dst_entry *dst;
struct flowi fl;
u8 syncookies;
+ const struct tcp_ao_hdr *aoh = NULL;
+
+#ifdef CONFIG_TCP_AO
+ /* TODO: Add an option to require TCP-AO signature */
+ /* Packet was already validated in tcp_v[46]_rcv */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ goto drop; /* Invalid TCP options */
+#endif

syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);

@@ -6928,7 +6936,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
* limitations, they conserve resources and peer is
* evidently real one.
*/
- if ((syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) {
+ if (!aoh && (syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) {
want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name);
if (!want_cookie)
goto drop;
@@ -7007,6 +7015,15 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
inet_rsk(req)->ecn_ok = 0;
}

+#ifdef CONFIG_TCP_AO
+ 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 003c5f320bfc..55c763b8bf24 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1064,30 +1064,73 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
+ struct tcp_md5sig_key *md5_key = NULL;
+ struct tcp_ao_key *ao_key = NULL;
const union tcp_md5_addr *addr;
- int l3index;
+ u8 keyid = 0;
+#ifdef CONFIG_TCP_AO
+ u8 traffic_key[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align;
+ const struct tcp_ao_hdr *aoh;
+#else
+ u8 *traffic_key = NULL;
+#endif

/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
*/
u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
tcp_sk(sk)->snd_nxt;
+ addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+
+ if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+
+ if (!aoh)
+ return;
+
+ ao_key = tcp_ao_do_lookup(sk, addr, AF_INET,
+ aoh->rnext_keyid, -1, 0);
+ if (unlikely(!ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ ao_key = tcp_ao_do_lookup(sk, addr,
+ AF_INET, -1, -1, 0);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!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;
+ }
+ }

+ keyid = aoh->keyid;
+ tcp_v4_ao_calc_key_rsk(ao_key, traffic_key, req);
+#endif
+ } else {
+ int l3index;
+
+ l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
+ md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
+ }
/* 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:
*/
- addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
- l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
tcp_v4_send_ack(sk, skb, seq,
tcp_rsk(req)->rcv_nxt,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
req->ts_recent,
0,
- tcp_md5_do_lookup(sk, l3index, addr, AF_INET),
- NULL, NULL, 0, 0,
+ md5_key, ao_key, traffic_key, keyid, 0,
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos);
}
@@ -1603,6 +1646,10 @@ 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
@@ -1704,7 +1751,7 @@ 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)) {
/*
* We're using one, so create a matching key
* on the newsk structure. If we fail to get
@@ -1715,6 +1762,10 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
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 94012a015bd0..03f1b809866b 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -473,6 +473,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
struct inet_connection_sock *newicsk;
struct tcp_sock *oldtp, *newtp;
u32 seq;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_key *ao_key;
+#endif

if (!newsk)
return NULL;
@@ -551,6 +554,13 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
if (treq->af_specific->req_md5_lookup(sk, req_to_sk(req)))
newtp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
#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 26315cac09dd..81f897f95147 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -606,6 +606,7 @@ 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_ao_key *ao_key)
{
@@ -636,6 +637,14 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
(ao_key->sndid << 8) |
(ao_info->rnext_key->rcvid));
}
+ if (tcprsk) {
+ u8 aolen = tcprsk->maclen + sizeof(struct tcp_ao_hdr);
+
+ maclen = tcprsk->maclen;
+ *ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) |
+ (tcprsk->ao_keyid << 8) |
+ (tcprsk->ao_rcv_next));
+ }
opts->hash_location = (__u8 *)ptr;
ptr += maclen / sizeof(*ptr);
if (unlikely(maclen % sizeof(*ptr))) {
@@ -1414,7 +1423,7 @@ 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, ao_key);
+ tcp_options_write(th, tp, NULL, &opts, ao_key);

#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
@@ -3700,7 +3709,7 @@ 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, NULL);
+ tcp_options_write(th, NULL, NULL, &opts, NULL);
th->doff = (tcp_header_size >> 2);
__TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);

diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 7fd31c60488a..31ae504af8e6 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -53,6 +53,18 @@ int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
htons(sk->sk_num), disn, sisn);
}

+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)
@@ -70,6 +82,15 @@ 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 crypto_pool_ahash *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 bab4a1883b3c..7610fdf5d519 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
@@ -1220,9 +1224,51 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
+ struct tcp_md5sig_key *md5_key = NULL;
+ struct tcp_ao_key *ao_key = NULL;
+ const struct in6_addr *addr;
+ u8 keyid = 0;
+#ifdef CONFIG_TCP_AO
+ char traffic_key[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align;
+ const struct tcp_ao_hdr *aoh;
+#else
+ u8 *traffic_key = NULL;
+#endif
int l3index;

l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+ addr = &ipv6_hdr(skb)->saddr;
+
+ if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+ if (!aoh)
+ return;
+ ao_key = tcp_v6_ao_do_lookup(sk, addr, aoh->rnext_keyid, -1);
+ if (unlikely(!ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ ao_key = tcp_v6_ao_do_lookup(sk, addr, -1, -1);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!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;
+ }
+ }
+
+ keyid = aoh->keyid;
+ tcp_v6_ao_calc_key_rsk(ao_key, traffic_key, req);
+#endif
+ } else {
+ md5_key = tcp_v6_md5_do_lookup(sk, addr, l3index);
+ }

/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
@@ -1238,9 +1284,9 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
req->ts_recent, sk->sk_bound_dev_if,
- tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
+ md5_key,
ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority,
- NULL, NULL, 0, 0);
+ ao_key, traffic_key, keyid, 0);
}

@@ -1470,18 +1516,26 @@ 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) {
- /* We're using one, so create a matching key
- * on the newsk structure. If we fail to get
- * memory, then we end up not copying the key
- * across. Shucks.
- */
- tcp_md5_key_copy(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
- AF_INET6, 128, l3index, key);
+ if (!tcp_rsk_used_ao(req)) {
+ const struct in6_addr *daddr = &newsk->sk_v6_daddr;
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_v6_md5_do_lookup(sk, daddr, l3index);
+ if (key) {
+ /* We're using one, so create a matching key
+ * on the newsk structure. If we fail to get
+ * memory, then we end up not copying the key
+ * across. Shucks.
+ */
+ tcp_md5_key_copy(newsk, (union tcp_md5_addr *)daddr,
+ AF_INET6, 128, l3index, key);
+ }
}
#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);
--
2.37.2