Commit 15e2396d authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

net: Infrastructure for CHECKSUM_PARTIAL with remote checsum offload 



This patch adds infrastructure so that remote checksum offload can
set CHECKSUM_PARTIAL instead of calling csum_partial and writing
the modfied checksum field.

Add skb_remcsum_adjust_partial function to set an skb for using
CHECKSUM_PARTIAL with remote checksum offload.  Changed
skb_remcsum_process and skb_gro_remcsum_process to take a boolean
argument to indicate if checksum partial can be set or the
checksum needs to be modified using the normal algorithm.

Signed-off-by: default avatarTom Herbert <therbert@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent baa32ff4

drivers/net/vxlan.c

+2 −2
Original line number Diff line number Diff line
@@ -580,7 +580,7 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb, 
	}



	skb_gro_remcsum_process(skb, (void *)vh + hdrlen,

				start, offset, grc);

				start, offset, grc, true);



	skb->remcsum_offload = 1;
@@ -1171,7 +1171,7 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh, 


	vh = (struct vxlanhdr *)(udp_hdr(skb) + 1);



	skb_remcsum_process(skb, (void *)vh + hdrlen, start, offset);

	skb_remcsum_process(skb, (void *)vh + hdrlen, start, offset, true);



	return vh;

}

include/linux/netdevice.h

+18 −1
Original line number Diff line number Diff line
@@ -1923,6 +1923,9 @@ struct napi_gro_cb { 
	/* Number of segments aggregated. */

	u16	count;



	/* Start offset for remote checksum offload */

	u16	gro_remcsum_start;



	/* jiffies when first packet was created/queued */

	unsigned long age;
@@ -2244,6 +2247,12 @@ static inline void skb_gro_postpull_rcsum(struct sk_buff *skb, 


__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);



static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)

{

	return (NAPI_GRO_CB(skb)->gro_remcsum_start - skb_headroom(skb) ==

		skb_gro_offset(skb));

}



static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,

						      bool zero_okay,

						      __sum16 check)
@@ -2251,6 +2260,7 @@ static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb, 
	return ((skb->ip_summed != CHECKSUM_PARTIAL ||

		skb_checksum_start_offset(skb) <

		 skb_gro_offset(skb)) &&

		!skb_at_gro_remcsum_start(skb) &&

		NAPI_GRO_CB(skb)->csum_cnt == 0 &&

		(!zero_okay || check));

}
@@ -2337,12 +2347,19 @@ static inline void skb_gro_remcsum_init(struct gro_remcsum *grc) 


static inline void skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,

					   int start, int offset,

					   struct gro_remcsum *grc)

					   struct gro_remcsum *grc,

					   bool nopartial)

{

	__wsum delta;



	BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);



	if (!nopartial) {

		NAPI_GRO_CB(skb)->gro_remcsum_start =

		    ((unsigned char *)ptr + start) - skb->head;

		return;

	}



	delta = remcsum_adjust(ptr, NAPI_GRO_CB(skb)->csum, start, offset);



	/* Adjust skb->csum since we changed the packet */

include/linux/skbuff.h

+14 −1
Original line number Diff line number Diff line
@@ -3104,16 +3104,29 @@ do { \ 
				       compute_pseudo(skb, proto));	\

} while (0)



static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,

					      u16 start, u16 offset)

{

	skb->ip_summed = CHECKSUM_PARTIAL;

	skb->csum_start = ((unsigned char *)ptr + start) - skb->head;

	skb->csum_offset = offset - start;

}



/* Update skbuf and packet to reflect the remote checksum offload operation.

 * When called, ptr indicates the starting point for skb->csum when

 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete

 * here, skb_postpull_rcsum is done so skb->csum start is ptr.

 */

static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,

				       int start, int offset)

				       int start, int offset, bool nopartial)

{

	__wsum delta;



	if (!nopartial) {

		skb_remcsum_adjust_partial(skb, ptr, start, offset);

		return;

	}



	 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {

		__skb_checksum_complete(skb);

		skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);

net/core/dev.c

+1 −0
Original line number Diff line number Diff line
@@ -4024,6 +4024,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff 
		NAPI_GRO_CB(skb)->flush = 0;

		NAPI_GRO_CB(skb)->free = 0;

		NAPI_GRO_CB(skb)->udp_mark = 0;

		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;



		/* Setup for GRO checksum validation */

		switch (skb->ip_summed) {

net/ipv4/fou.c

+2 −2
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr, 
		return NULL;

	guehdr = (struct guehdr *)&udp_hdr(skb)[1];



	skb_remcsum_process(skb, (void *)guehdr + hdrlen, start, offset);

	skb_remcsum_process(skb, (void *)guehdr + hdrlen, start, offset, true);



	return guehdr;

}
@@ -230,7 +230,7 @@ static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off, 
	}



	skb_gro_remcsum_process(skb, (void *)guehdr + hdrlen,

				start, offset, grc);

				start, offset, grc, true);



	skb->remcsum_offload = 1;

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