1 files changed, 15 insertions, 16 deletions

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index a2b68a1..0560635 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -274,33 +274,32 @@ static struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *
 {
 	const struct iphdr *iph = skb_gro_network_header(skb);
 	__wsum wsum;
-	__sum16 sum;
+
+	/* Don't bother verifying checksum if we're going to flush anyway. */
+	if (NAPI_GRO_CB(skb)->flush)
+		goto skip_csum;
+
+	wsum = skb->csum;
 
 	switch (skb->ip_summed) {
+	case CHECKSUM_NONE:
+		wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb),
+				    0);
+
+		/* fall through */
+
 	case CHECKSUM_COMPLETE:
 		if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
-				  skb->csum)) {
+				  wsum)) {
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 			break;
 		}
-flush:
+
 		NAPI_GRO_CB(skb)->flush = 1;
 		return NULL;
-
-	case CHECKSUM_NONE:
-		wsum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
-					  skb_gro_len(skb), IPPROTO_TCP, 0);
-		sum = csum_fold(skb_checksum(skb,
-					     skb_gro_offset(skb),
-					     skb_gro_len(skb),
-					     wsum));
-		if (sum)
-			goto flush;
-
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		break;
 	}
 
+skip_csum:
 	return tcp_gro_receive(head, skb);
 }