1 files changed, 19 insertions, 8 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d04632673a9e..cfe6ffe1c177 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -702,7 +702,8 @@ static unsigned int tcp_synack_options(struct sock *sk,
                                    unsigned int mss, struct sk_buff *skb,
                                    struct tcp_out_options *opts,
                                    struct tcp_md5sig_key **md5,
-                                   struct tcp_extend_values *xvp)
+                                   struct tcp_extend_values *xvp,
+                                   struct tcp_fastopen_cookie *foc)
 {
         struct inet_request_sock *ireq = inet_rsk(req);
         unsigned int remaining = MAX_TCP_OPTION_SPACE;
@@ -747,7 +748,15 @@ static unsigned int tcp_synack_options(struct sock *sk,
                 if (unlikely(!ireq->tstamp_ok))
                         remaining -= TCPOLEN_SACKPERM_ALIGNED;
         }
-
+        if (foc != NULL) {
+                u32 need = TCPOLEN_EXP_FASTOPEN_BASE + foc->len;
+                need = (need + 3) & ~3U;  /* Align to 32 bits */
+                if (remaining >= need) {
+                        opts->options |= OPTION_FAST_OPEN_COOKIE;
+                        opts->fastopen_cookie = foc;
+                        remaining -= need;
+                }
+        }
         /* Similar rationale to tcp_syn_options() applies here, too.
          * If the <SYN> options fit, the same options should fit now!
          */
@@ -2028,10 +2037,10 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                 if (push_one)
                         break;
         }
-        if (inet_csk(sk)->icsk_ca_state == TCP_CA_Recovery)
-                tp->prr_out += sent_pkts;
 
         if (likely(sent_pkts)) {
+                if (tcp_in_cwnd_reduction(sk))
+                        tp->prr_out += sent_pkts;
                 tcp_cwnd_validate(sk);
                 return false;
         }
@@ -2533,7 +2542,7 @@ begin_fwd:
                 }
                 NET_INC_STATS_BH(sock_net(sk), mib_idx);
 
-                if (inet_csk(sk)->icsk_ca_state == TCP_CA_Recovery)
+                if (tcp_in_cwnd_reduction(sk))
                         tp->prr_out += tcp_skb_pcount(skb);
 
                 if (skb == tcp_write_queue_head(sk))
@@ -2658,7 +2667,8 @@ int tcp_send_synack(struct sock *sk)
  */
 struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
                                 struct request_sock *req,
-                                struct request_values *rvp)
+                                struct request_values *rvp,
+                                struct tcp_fastopen_cookie *foc)
 {
         struct tcp_out_options opts;
         struct tcp_extend_values *xvp = tcp_xv(rvp);
@@ -2718,7 +2728,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 #endif
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
         tcp_header_size = tcp_synack_options(sk, req, mss,
-                                             skb, &opts, &md5, xvp)
+                                             skb, &opts, &md5, xvp, foc)
                         + sizeof(*th);
 
         skb_push(skb, tcp_header_size);
@@ -2772,7 +2782,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
         }
 
         th->seq = htonl(TCP_SKB_CB(skb)->seq);
-        th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
+        /* XXX data is queued and acked as is. No buffer/window check */
+        th->ack_seq = htonl(tcp_rsk(req)->rcv_nxt);
 
         /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
         th->window = htons(min(req->rcv_wnd, 65535U));