diff options
Diffstat (limited to 'sys/netinet/tcp_input.c')
| -rw-r--r-- | sys/netinet/tcp_input.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 337871e8fdc2..9bf6f52855a7 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -2673,9 +2673,16 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, tp->t_dupacks = 0; /* * If this ack also has new SACK info, increment the - * counter as per rfc6675. + * counter as per rfc6675. The variable + * sack_changed tracks all changes to the SACK + * scoreboard, including when partial ACKs without + * SACK options are received, and clear the scoreboard + * from the left side. Such partial ACKs should not be + * counted as dupacks here. */ - if ((tp->t_flags & TF_SACK_PERMIT) && sack_changed) + if ((tp->t_flags & TF_SACK_PERMIT) && + (to.to_flags & TOF_SACK) && + sack_changed) tp->t_dupacks++; } |