diff options
Diffstat (limited to 'net/ipv4/tcp_ao.c')
| -rw-r--r-- | net/ipv4/tcp_ao.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index e478341fc336..007f29a2531f 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -262,6 +262,171 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, return -EOPNOTSUPP; } +static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp, + __be32 daddr, __be32 saddr, + int nbytes) +{ + struct tcp4_pseudohdr *bp; + struct scatterlist sg; + + bp = hp->scratch; + bp->saddr = saddr; + bp->daddr = daddr; + bp->pad = 0; + bp->protocol = IPPROTO_TCP; + bp->len = cpu_to_be16(nbytes); + + sg_init_one(&sg, bp, sizeof(*bp)); + ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp)); + return crypto_ahash_update(hp->req); +} + +static int tcp_ao_hash_pseudoheader(unsigned short int family, + const struct sock *sk, + const struct sk_buff *skb, + struct tcp_sigpool *hp, int nbytes) +{ + const struct tcphdr *th = tcp_hdr(skb); + + /* TODO: Can we rely on checksum being zero to mean outbound pkt? */ + if (!th->check) { + if (family == AF_INET) + return tcp_v4_ao_hash_pseudoheader(hp, sk->sk_daddr, + sk->sk_rcv_saddr, skb->len); +#if IS_ENABLED(CONFIG_IPV6) + else if (family == AF_INET6) + return tcp_v6_ao_hash_pseudoheader(hp, &sk->sk_v6_daddr, + &sk->sk_v6_rcv_saddr, skb->len); +#endif + else + return -EAFNOSUPPORT; + } + + if (family == AF_INET) { + const struct iphdr *iph = ip_hdr(skb); + + return tcp_v4_ao_hash_pseudoheader(hp, iph->daddr, + iph->saddr, skb->len); +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + const struct ipv6hdr *iph = ipv6_hdr(skb); + + return tcp_v6_ao_hash_pseudoheader(hp, &iph->daddr, + &iph->saddr, skb->len); +#endif + } + return -EAFNOSUPPORT; +} + +/* tcp_ao_hash_sne(struct tcp_sigpool *hp) + * @hp - used for hashing + * @sne - sne value + */ +static int tcp_ao_hash_sne(struct tcp_sigpool *hp, u32 sne) +{ + struct scatterlist sg; + __be32 *bp; + + bp = (__be32 *)hp->scratch; + *bp = htonl(sne); + + sg_init_one(&sg, bp, sizeof(*bp)); + ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp)); + return crypto_ahash_update(hp->req); +} + +static int tcp_ao_hash_header(struct tcp_sigpool *hp, + const struct tcphdr *th, + bool exclude_options, u8 *hash, + int hash_offset, int hash_len) +{ + int err, len = th->doff << 2; + struct scatterlist sg; + u8 *hdr = hp->scratch; + + /* We are not allowed to change tcphdr, make a local copy */ + if (exclude_options) { + len = sizeof(*th) + sizeof(struct tcp_ao_hdr) + hash_len; + memcpy(hdr, th, sizeof(*th)); + memcpy(hdr + sizeof(*th), + (u8 *)th + hash_offset - sizeof(struct tcp_ao_hdr), + sizeof(struct tcp_ao_hdr)); + memset(hdr + sizeof(*th) + sizeof(struct tcp_ao_hdr), + 0, hash_len); + ((struct tcphdr *)hdr)->check = 0; + } else { + len = th->doff << 2; + memcpy(hdr, th, len); + /* zero out tcp-ao hash */ + ((struct tcphdr *)hdr)->check = 0; + memset(hdr + hash_offset, 0, hash_len); + } + + sg_init_one(&sg, hdr, len); + ahash_request_set_crypt(hp->req, &sg, NULL, len); + err = crypto_ahash_update(hp->req); + WARN_ON_ONCE(err != 0); + return err; +} + +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, + const u8 *tkey, int hash_offset, u32 sne) +{ + const struct tcphdr *th = tcp_hdr(skb); + int tkey_len = tcp_ao_digest_size(key); + struct tcp_sigpool hp; + void *hash_buf = NULL; + + hash_buf = kmalloc(tkey_len, GFP_ATOMIC); + if (!hash_buf) + goto clear_hash_noput; + + 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; + + /* For now use sha1 by default. Depends on alg in tcp_ao_key */ + if (crypto_ahash_init(hp.req)) + goto clear_hash; + + if (tcp_ao_hash_sne(&hp, sne)) + goto clear_hash; + if (tcp_ao_hash_pseudoheader(family, sk, skb, &hp, skb->len)) + goto clear_hash; + if (tcp_ao_hash_header(&hp, th, false, + ao_hash, hash_offset, tcp_ao_maclen(key))) + goto clear_hash; + if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2)) + goto clear_hash; + ahash_request_set_crypt(hp.req, NULL, hash_buf, 0); + if (crypto_ahash_final(hp.req)) + goto clear_hash; + + memcpy(ao_hash, hash_buf, tcp_ao_maclen(key)); + tcp_sigpool_end(&hp); + kfree(hash_buf); + return 0; + +clear_hash: + tcp_sigpool_end(&hp); +clear_hash_noput: + memset(ao_hash, 0, tcp_ao_maclen(key)); + kfree(hash_buf); + return 1; +} + +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) +{ + return tcp_ao_hash_skb(AF_INET, ao_hash, key, sk, skb, + tkey, hash_offset, sne); +} + struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid) { @@ -270,6 +435,40 @@ 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); } +int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, + struct tcp_ao_key *key, struct tcphdr *th, + __u8 *hash_location) +{ + struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_ao_info *ao; + void *tkey_buf = NULL; + u8 *traffic_key; + + ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, + lockdep_sock_is_held(sk)); + traffic_key = snd_other_key(key); + if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) { + __be32 disn; + + if (!(tcb->tcp_flags & TCPHDR_ACK)) { + disn = 0; + tkey_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC); + if (!tkey_buf) + return -ENOMEM; + traffic_key = tkey_buf; + } else { + disn = ao->risn; + } + tp->af_specific->ao_calc_key_sk(key, traffic_key, + sk, ao->lisn, disn, true); + } + tp->af_specific->calc_ao_hash(hash_location, key, sk, skb, traffic_key, + hash_location - (u8 *)th, 0); + kfree(tkey_buf); + return 0; +} + static int tcp_ao_cache_traffic_keys(const struct sock *sk, struct tcp_ao_info *ao, struct tcp_ao_key *ao_key) |