3 files changed, 30 insertions, 5 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 7ec6a28305c0..1f57c5363492 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -763,10 +763,17 @@ enum tcp_ca_event {
         CA_EVENT_CWND_RESTART,  /* congestion window restart */
         CA_EVENT_COMPLETE_CWR,  /* end of congestion recovery */
         CA_EVENT_LOSS,          /* loss timeout */
+        CA_EVENT_ECN_NO_CE,     /* ECT set, but not CE marked */
+        CA_EVENT_ECN_IS_CE,     /* received CE marked IP packet */
+        CA_EVENT_DELAYED_ACK,   /* Delayed ack is sent */
+        CA_EVENT_NON_DELAYED_ACK,
 };
 
+/* Information about inbound ACK, passed to cong_ops->in_ack_event() */
 enum tcp_ca_ack_event_flags {
-        CA_ACK_SLOWPATH = (1 << 0),
+        CA_ACK_SLOWPATH         = (1 << 0),     /* In slow path processing */
+        CA_ACK_WIN_UPDATE       = (1 << 1),     /* ACK updated window */
+        CA_ACK_ECE              = (1 << 2),     /* ECE bit is set on ack */
 };
 
 /*
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8a38774cc66e..fc133178c787 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -233,14 +233,21 @@ static inline void TCP_ECN_check_ce(struct tcp_sock *tp, const struct sk_buff *s
                         tcp_enter_quickack_mode((struct sock *)tp);
                 break;
         case INET_ECN_CE:
+                if (tcp_ca_needs_ecn((struct sock *)tp))
+                        tcp_ca_event((struct sock *)tp, CA_EVENT_ECN_IS_CE);
+
                 if (!(tp->ecn_flags & TCP_ECN_DEMAND_CWR)) {
                         /* Better not delay acks, sender can have a very low cwnd */
                         tcp_enter_quickack_mode((struct sock *)tp);
                         tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
                 }
-                /* fallinto */
+                tp->ecn_flags |= TCP_ECN_SEEN;
+                break;
         default:
+                if (tcp_ca_needs_ecn((struct sock *)tp))
+                        tcp_ca_event((struct sock *)tp, CA_EVENT_ECN_NO_CE);
                 tp->ecn_flags |= TCP_ECN_SEEN;
+                break;
         }
 }
 
@@ -3429,10 +3436,12 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
                 tp->snd_una = ack;
                 flag |= FLAG_WIN_UPDATE;
 
-                tcp_in_ack_event(sk, 0);
+                tcp_in_ack_event(sk, CA_ACK_WIN_UPDATE);
 
                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPACKS);
         } else {
+                u32 ack_ev_flags = CA_ACK_SLOWPATH;
+
                 if (ack_seq != TCP_SKB_CB(skb)->end_seq)
                         flag |= FLAG_DATA;
                 else
@@ -3444,10 +3453,15 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
                         flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
                                                         &sack_rtt_us);
 
-                if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb)))
+                if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb))) {
                         flag |= FLAG_ECE;
+                        ack_ev_flags |= CA_ACK_ECE;
+                }
+
+                if (flag & FLAG_WIN_UPDATE)
+                        ack_ev_flags |= CA_ACK_WIN_UPDATE;
 
-                tcp_in_ack_event(sk, CA_ACK_SLOWPATH);
+                tcp_in_ack_event(sk, ack_ev_flags);
         }
 
         /* We passed data and got it acked, remove any soft error
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 20e73271d75c..124f9e4e4594 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3130,6 +3130,8 @@ void tcp_send_delayed_ack(struct sock *sk)
         int ato = icsk->icsk_ack.ato;
         unsigned long timeout;
 
+        tcp_ca_event(sk, CA_EVENT_DELAYED_ACK);
+
         if (ato > TCP_DELACK_MIN) {
                 const struct tcp_sock *tp = tcp_sk(sk);
                 int max_ato = HZ / 2;
@@ -3186,6 +3188,8 @@ void tcp_send_ack(struct sock *sk)
         if (sk->sk_state == TCP_CLOSE)
                 return;
 
+        tcp_ca_event(sk, CA_EVENT_NON_DELAYED_ACK);
+
         /* We are not putting this on the write queue, so
          * tcp_transmit_skb() will set the ownership to this
          * sock.