diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 9b947a9aaf6e..62e48cf84e60 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -72,27 +72,58 @@ error: kfree(ctx); return err; } -/* Computes the fastopen cookie for the IP path. - * The path is a 128 bits long (pad with zeros for IPv4). - * - * The caller must check foc->len to determine if a valid cookie - * has been generated successfully. -*/ -void tcp_fastopen_cookie_gen(__be32 src, __be32 dst, - struct tcp_fastopen_cookie *foc) +static bool __tcp_fastopen_cookie_gen(const void *path, + struct tcp_fastopen_cookie *foc) { - __be32 path[4] = { src, dst, 0, 0 }; struct tcp_fastopen_context *ctx; + bool ok = false; tcp_fastopen_init_key_once(true); rcu_read_lock(); ctx = rcu_dereference(tcp_fastopen_ctx); if (ctx) { - crypto_cipher_encrypt_one(ctx->tfm, foc->val, (__u8 *)path); + crypto_cipher_encrypt_one(ctx->tfm, foc->val, path); foc->len = TCP_FASTOPEN_COOKIE_SIZE; + ok = true; } rcu_read_unlock(); + return ok; +} + +/* Generate the fastopen cookie by doing aes128 encryption on both + * the source and destination addresses. Pad 0s for IPv4 or IPv4-mapped-IPv6 + * addresses. For the longer IPv6 addresses use CBC-MAC. + * + * XXX (TFO) - refactor when TCP_FASTOPEN_COOKIE_SIZE != AES_BLOCK_SIZE. + */ +static bool tcp_fastopen_cookie_gen(struct request_sock *req, + struct sk_buff *syn, + struct tcp_fastopen_cookie *foc) +{ + if (req->rsk_ops->family == AF_INET) { + const struct iphdr *iph = ip_hdr(syn); + + __be32 path[4] = { iph->saddr, iph->daddr, 0, 0 }; + return __tcp_fastopen_cookie_gen(path, foc); + } + +#if IS_ENABLED(CONFIG_IPV6) + if (req->rsk_ops->family == AF_INET6) { + const struct ipv6hdr *ip6h = ipv6_hdr(syn); + struct tcp_fastopen_cookie tmp; + + if (__tcp_fastopen_cookie_gen(&ip6h->saddr, &tmp)) { + struct in6_addr *buf = (struct in6_addr *) tmp.val; + int i = 4; + + for (i = 0; i < 4; i++) + buf->s6_addr32[i] ^= ip6h->daddr.s6_addr32[i]; + return __tcp_fastopen_cookie_gen(buf, foc); + } + } +#endif + return false; } static bool tcp_fastopen_create_child(struct sock *sk, @@ -234,10 +265,8 @@ bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, if (syn_data && (sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD)) goto fastopen; - tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, - ip_hdr(skb)->daddr, &valid_foc); - - if (foc->len == TCP_FASTOPEN_COOKIE_SIZE && + if (tcp_fastopen_cookie_gen(req, skb, &valid_foc) && + foc->len == TCP_FASTOPEN_COOKIE_SIZE && foc->len == valid_foc.len && !memcmp(foc->val, valid_foc.val, foc->len)) { /* Cookie is valid. Create a (full) child socket to accept diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index a7a62ce12b3f..3a267bf14f2f 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -472,7 +472,8 @@ out: static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, struct flowi6 *fl6, struct request_sock *req, - u16 queue_mapping) + u16 queue_mapping, + struct tcp_fastopen_cookie *foc) { struct inet_request_sock *ireq = inet_rsk(req); struct ipv6_pinfo *np = inet6_sk(sk); @@ -483,7 +484,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL) goto done; - skb = tcp_make_synack(sk, dst, req, NULL); + skb = tcp_make_synack(sk, dst, req, foc); if (skb) { __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, @@ -507,7 +508,7 @@ static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req) struct flowi6 fl6; int res; - res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0); + res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0, NULL); if (!res) { TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); @@ -926,7 +927,12 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, + /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV + * sk->sk_state == TCP_SYN_RECV -> for Fast Open. + */ + tcp_v6_send_ack(skb, (sk->sk_state == TCP_LISTEN) ? + tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, + tcp_rsk(req)->rcv_nxt, req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if, tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0, 0); @@ -978,8 +984,10 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) struct tcp_sock *tp = tcp_sk(sk); __u32 isn = TCP_SKB_CB(skb)->when; struct dst_entry *dst = NULL; + struct tcp_fastopen_cookie foc = { .len = -1 }; + bool want_cookie = false, fastopen; struct flowi6 fl6; - bool want_cookie = false; + int err; if (skb->protocol == htons(ETH_P_IP)) return tcp_v4_conn_request(sk, skb); @@ -1010,7 +1018,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) tcp_clear_options(&tmp_opt); tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); tmp_opt.user_mss = tp->rx_opt.user_mss; - tcp_parse_options(skb, &tmp_opt, 0, NULL); + tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc); if (want_cookie && !tmp_opt.saw_tstamp) tcp_clear_options(&tmp_opt); @@ -1083,19 +1091,27 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) isn = tcp_v6_init_sequence(skb); } have_isn: - tcp_rsk(req)->snt_isn = isn; if (security_inet_conn_request(sk, skb, req)) goto drop_and_release; - if (tcp_v6_send_synack(sk, dst, &fl6, req, - skb_get_queue_mapping(skb)) || - want_cookie) + if (!dst && (dst = inet6_csk_route_req(sk, &fl6, req)) == NULL) goto drop_and_free; + tcp_rsk(req)->snt_isn = isn; tcp_rsk(req)->snt_synack = tcp_time_stamp; - tcp_rsk(req)->listener = NULL; - inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); + tcp_openreq_init_rwin(req, sk, dst); + fastopen = !want_cookie && + tcp_try_fastopen(sk, skb, req, &foc, dst); + err = tcp_v6_send_synack(sk, dst, &fl6, req, + skb_get_queue_mapping(skb), &foc); + if (!fastopen) { + if (err || want_cookie) + goto drop_and_free; + + tcp_rsk(req)->listener = NULL; + inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); + } return 0; drop_and_release: