1 files changed, 13 insertions, 3 deletions

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index d02ff3777785..99779ae44f64 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -32,6 +32,8 @@ enum tcp_metric_index {
 
 struct tcp_fastopen_metrics {
         u16     mss;
+        u16     syn_loss:10;            /* Recurring Fast Open SYN losses */
+        unsigned long   last_syn_loss;  /* Last Fast Open SYN loss */
         struct  tcp_fastopen_cookie     cookie;
 };
 
@@ -125,6 +127,7 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst)
         tm->tcpm_ts = 0;
         tm->tcpm_ts_stamp = 0;
         tm->tcpm_fastopen.mss = 0;
+        tm->tcpm_fastopen.syn_loss = 0;
         tm->tcpm_fastopen.cookie.len = 0;
 }
 
@@ -644,7 +647,8 @@ bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw)
 static DEFINE_SEQLOCK(fastopen_seqlock);
 
 void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
-                            struct tcp_fastopen_cookie *cookie)
+                            struct tcp_fastopen_cookie *cookie,
+                            int *syn_loss, unsigned long *last_syn_loss)
 {
         struct tcp_metrics_block *tm;
 
@@ -659,14 +663,15 @@ void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
                         if (tfom->mss)
                                 *mss = tfom->mss;
                         *cookie = tfom->cookie;
+                        *syn_loss = tfom->syn_loss;
+                        *last_syn_loss = *syn_loss ? tfom->last_syn_loss : 0;
                 } while (read_seqretry(&fastopen_seqlock, seq));
         }
         rcu_read_unlock();
 }
 
-
 void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
-                            struct tcp_fastopen_cookie *cookie)
+                            struct tcp_fastopen_cookie *cookie, bool syn_lost)
 {
         struct tcp_metrics_block *tm;
 
@@ -679,6 +684,11 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
                 tfom->mss = mss;
                 if (cookie->len > 0)
                         tfom->cookie = *cookie;
+                if (syn_lost) {
+                        ++tfom->syn_loss;
+                        tfom->last_syn_loss = jiffies;
+                } else
+                        tfom->syn_loss = 0;
                 write_sequnlock_bh(&fastopen_seqlock);
         }
         rcu_read_unlock();