From 861b650101eb0c627d171eb18de81dddb93d395e Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 27 Sep 2012 02:14:53 +0000
Subject: [PATCH] tcp: gro: add checksuming helpers
skb with CHECKSUM_NONE cant currently be handled by GRO, and
we notice this deep in GRO stack in tcp[46]_gro_receive()
But there are cases where GRO can be a benefit, even with a lack
of checksums.
This preliminary work is needed to add GRO support
to tunnels.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_ipv4.c | 19 ++++++++++++++++---
net/ipv6/tcp_ipv6.c | 20 +++++++++++++++++---
2 files changed, 33 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 385eb79cf6aad..75735c9a6a9df 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2803,6 +2803,8 @@ void tcp4_proc_exit(void)
struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
{
const struct iphdr *iph = skb_gro_network_header(skb);
+ __wsum wsum;
+ __sum16 sum;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
@@ -2811,11 +2813,22 @@ struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
}
-
- /* fall through */
- case CHECKSUM_NONE:
+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;
}
return tcp_gro_receive(head, skb);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d6212d6bc8d89..49c890386ce9b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -763,6 +763,8 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
const struct ipv6hdr *iph = skb_gro_network_header(skb);
+ __wsum wsum;
+ __sum16 sum;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
@@ -771,11 +773,23 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
}
-
- /* fall through */
- case CHECKSUM_NONE:
+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;
}
return tcp_gro_receive(head, skb);