Commit 861b6501 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 64c6d08e

net/ipv4/tcp_ipv4.c

+16 −3
Original line number Diff line number Diff line
@@ -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);

net/ipv6/tcp_ipv6.c

+17 −3
Original line number Diff line number Diff line
@@ -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);

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