svn commit: r220428 - head/sys/netinet

[Jack F Vogel]

Author: jfv
Date: Thu Apr  7 21:20:26 2011
New Revision: 220428
URL: http://svn.freebsd.org/changeset/base/220428

Log:
  Port of the LRO fix from mxge driver to the generic
  LRO code. Thanks to Andrew Gallatin for the change.
  
  MFC after:  7 days

Modified:
  head/sys/netinet/tcp_lro.c

Modified: head/sys/netinet/tcp_lro.c
==============================================================================
--- head/sys/netinet/tcp_lro.c	Thu Apr  7 20:15:36 2011	(r220427)
+++ head/sys/netinet/tcp_lro.c	Thu Apr  7 21:20:26 2011	(r220428)
@@ -279,8 +279,10 @@ tcp_lro_rx(struct lro_ctrl *cntl, struct
 		    lro->dest_ip == ip->ip_dst.s_addr) {
 			/* Try to append it */
 
-			if (__predict_false(seq != lro->next_seq)) {
-				/* out of order packet */
+			if (__predict_false(seq != lro->next_seq ||
+				    (tcp_data_len == 0 &&
+				    lro->ack_seq == tcp->th_ack))) {
+				/* out of order packet or dup ack */
 				SLIST_REMOVE(&cntl->lro_active, lro,
 					     lro_entry, next);
 				tcp_lro_flush(cntl, lro);