lib: Fix delayed ACK under high load

The delayed ACK was wrongly measuring the delay against the receiver
activity instead of the sender activity. Also fixed receiver activity
not being updated for non-data packets (and duplicates and other
dropped traffic).

Signed-off-by: Dimitri Staessens <[email protected]>
Signed-off-by: Sander Vrijders <[email protected]>

1 files changed, 9 insertions, 3 deletions

diff --git a/src/lib/frct.c b/src/lib/frct.c
index 4effad3b..d6db6fea 100644
--- a/src/lib/frct.c
+++ b/src/lib/frct.c
@@ -302,7 +302,13 @@ static void send_frct_pkt(struct frcti * frcti)
         rwe   = frcti->rcv_cr.rwe;
 
         diff = ts_diff_ns(&frcti->rcv_cr.act, &now);
-        if (diff > frcti->a || diff < TICTIME) {
+        if (diff > frcti->a) {
+                pthread_rwlock_unlock(&frcti->lock);
+                return;
+        }
+
+        diff = ts_diff_ns(&frcti->snd_cr.act, &now);
+        if (diff < TICTIME) {
                 pthread_rwlock_unlock(&frcti->lock);
                 return;
         }
@@ -828,6 +834,8 @@ static void __frcti_rcv(struct frcti *       frcti,
                 }
         }
 
+        rcv_cr->act = now;
+
         /* For now, just send an immediate window update. */
         if (pci->flags & FRCT_RDVS) {
                 fd = frcti->fd;
@@ -914,8 +922,6 @@ static void __frcti_rcv(struct frcti *       frcti,
 
         frcti->rq[pos] = idx;
 
-        rcv_cr->act = now;
-
         pthread_rwlock_unlock(&frcti->lock);
 
         if (fd != -1)