Index: head/sys/netinet/tcp_stacks/fastpath.c
===================================================================
--- head/sys/netinet/tcp_stacks/fastpath.c
+++ head/sys/netinet/tcp_stacks/fastpath.c
@@ -172,7 +172,10 @@
 	       int ti_locked, u_long tiwin)
 {
 	int acked;
+	uint16_t nsegs;
 	int winup_only=0;
+
+	nsegs = max(1, m->m_pkthdr.lro_nsegs);
 #ifdef TCPDEBUG
 	/*
 	 * The size of tcp_saveipgen must be the size of the max ip header,
@@ -278,7 +281,7 @@
 		 * typically means increasing the congestion
 		 * window.
 		 */
-		cc_ack_received(tp, th, CC_ACK);
+		cc_ack_received(tp, th, nsegs, CC_ACK);
 
 		tp->snd_una = th->th_ack;
 		/*
@@ -502,9 +505,12 @@
 {
 	int  acked, ourfinisacked, needoutput = 0;
 	int rstreason, todrop, win;
+	uint16_t nsegs;
 	char *s;
 	struct in_conninfo *inc;
 	struct mbuf *mfree = NULL;
+
+	nsegs = max(1, m->m_pkthdr.lro_nsegs);
 #ifdef TCPDEBUG
 	/*
 	 * The size of tcp_saveipgen must be the size of the max ip header,
@@ -1085,7 +1091,8 @@
 					tp->t_dupacks = 0;
 				else if (++tp->t_dupacks > tcprexmtthresh ||
 				     IN_FASTRECOVERY(tp->t_flags)) {
-					cc_ack_received(tp, th, CC_DUPACK);
+					cc_ack_received(tp, th, nsegs,
+					    CC_DUPACK);
 					if ((tp->t_flags & TF_SACK_PERMIT) &&
 					    IN_FASTRECOVERY(tp->t_flags)) {
 						int awnd;
@@ -1135,7 +1142,8 @@
 					}
 					/* Congestion signal before ack. */
 					cc_cong_signal(tp, th, CC_NDUPACK);
-					cc_ack_received(tp, th, CC_DUPACK);
+					cc_ack_received(tp, th, nsegs,
+					    CC_DUPACK);
 					tcp_timer_activate(tp, TT_REXMT, 0);
 					tp->t_rtttime = 0;
 					if (tp->t_flags & TF_SACK_PERMIT) {
@@ -1169,7 +1177,8 @@
 					 * segment. Restore the original
 					 * snd_cwnd after packet transmission.
 					 */
-					cc_ack_received(tp, th, CC_DUPACK);
+					cc_ack_received(tp, th, nsegs,
+					    CC_DUPACK);
 					u_long oldcwnd = tp->snd_cwnd;
 					tcp_seq oldsndmax = tp->snd_max;
 					u_int sent;
@@ -1323,7 +1332,7 @@
 		 * control related information. This typically means increasing
 		 * the congestion window.
 		 */
-		cc_ack_received(tp, th, CC_ACK);
+		cc_ack_received(tp, th, nsegs, CC_ACK);
 
 		SOCKBUF_LOCK(&so->so_snd);
 		if (acked > sbavail(&so->so_snd)) {
@@ -1758,6 +1767,7 @@
 	int thflags;
 	u_long tiwin;
 	char *s;
+	uint16_t nsegs;
 	int can_enter;
 	struct in_conninfo *inc;
 	struct tcpopt to;
@@ -1765,6 +1775,7 @@
 	thflags = th->th_flags;
 	tp->sackhint.last_sack_ack = 0;
 	inc = &tp->t_inpcb->inp_inc;
+	nsegs = max(1, m->m_pkthdr.lro_nsegs);
 	/*
 	 * If this is either a state-changing packet or current state isn't
 	 * established, we require a write lock on tcbinfo.  Otherwise, we
@@ -1983,7 +1994,10 @@
 	       int ti_locked, u_long tiwin)
 {
 	int acked;
+	uint16_t nsegs;
 	int winup_only=0;
+
+	nsegs = max(1, m->m_pkthdr.lro_nsegs);
 #ifdef TCPDEBUG
 	/*
 	 * The size of tcp_saveipgen must be the size of the max ip header,
@@ -2128,7 +2142,7 @@
 		 * typically means increasing the congestion
 		 * window.
 		 */
-		cc_ack_received(tp, th, CC_ACK);
+		cc_ack_received(tp, th, nsegs, CC_ACK);
 
 		tp->snd_una = th->th_ack;
 		tp->t_dupacks = 0;