[TCP]: Wrap-safed reordering detection FRTO check
In case somebody has a suggestion about a better place for this
check, which must guarantee execution "early enough" (i.e,
before the wrap can occur), I'm very open to them.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c1339d8..7c1a92f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3027,6 +3027,9 @@
/* See if we can take anything off of the retransmit queue. */
flag |= tcp_clean_rtx_queue(sk, &seq_rtt);
+ /* Guarantee sacktag reordering detection against wrap-arounds */
+ if (before(tp->frto_highmark, tp->snd_una))
+ tp->frto_highmark = 0;
if (tp->frto_counter)
frto_cwnd = tcp_process_frto(sk, flag);
