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Diffstat (limited to 'net/ipv4/tcp_ao.c')
-rw-r--r--net/ipv4/tcp_ao.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index ee23356101f4..e478341fc336 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 +270,113 @@ 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 {
+ /* Can't happen: tcp_connect() verifies that there's
+ * at least one tcp-ao key that matches the remote peer.
+ */
+ WARN_ON_ONCE(1);
+ 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 +758,12 @@ 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);
generated by cgit (git 2.34.1) at 2024-05-25 20:44:25 +0000