[3.11.y.z extended stable] Patch "gro: Clean up tcpX_gro_receive checksum verification" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Wed Dec 11 14:40:36 UTC 2013


This is a note to let you know that I have just added a patch titled

    gro: Clean up tcpX_gro_receive checksum verification

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1af7c57d85b381537a4aa1ccf9287ce6a0b9fcc3 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert at gondor.apana.org.au>
Date: Fri, 22 Nov 2013 10:32:11 +0800
Subject: gro: Clean up tcpX_gro_receive checksum verification

commit b8ee93ba80b5a0b6c3c06b65c34dd1276f16c047 upstream.

This patch simplifies the checksum verification in tcpX_gro_receive
by reusing the CHECKSUM_COMPLETE code for CHECKSUM_NONE.  All it
does for CHECKSUM_NONE is compute the partial checksum and then
treat it as if it came from the hardware (CHECKSUM_COMPLETE).

Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>

Cheers,
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv4/tcp_offload.c   | 26 ++++++++++----------------
 net/ipv6/tcpv6_offload.c | 27 ++++++++++-----------------
 2 files changed, 20 insertions(+), 33 deletions(-)

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 44c8678..910ab81 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -272,35 +272,29 @@ 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:
diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
index 78081d8..a7a2384 100644
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -37,36 +37,29 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
 {
 	const struct ipv6hdr *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),
+				    wsum);
+
+		/* fall through */
+
 	case CHECKSUM_COMPLETE:
 		if (!tcp_v6_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_unfold(csum_ipv6_magic(&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:
--
1.8.3.2





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