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Commit da1b4195 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'bpf-csum-complete' 



Daniel Borkmann says:

====================
Few BPF helper related checksum fixes

The set contains three fixes with regards to CHECKSUM_COMPLETE
and BPF helper functions. For details please see individual
patches.

Thanks!

v1 -> v2:
  - Fixed make htmldocs issue reported by kbuild bot.
  - Rest as is.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 66cf3504 8065694e

include/linux/skbuff.h

+33 −19
Original line number Diff line number Diff line
@@ -2847,6 +2847,18 @@ static inline int skb_linearize_cow(struct sk_buff *skb) 
	       __skb_linearize(skb) : 0;

}



static __always_inline void

__skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,

		     unsigned int off)

{

	if (skb->ip_summed == CHECKSUM_COMPLETE)

		skb->csum = csum_block_sub(skb->csum,

					   csum_partial(start, len, 0), off);

	else if (skb->ip_summed == CHECKSUM_PARTIAL &&

		 skb_checksum_start_offset(skb) < 0)

		skb->ip_summed = CHECKSUM_NONE;

}



/**

 *	skb_postpull_rcsum - update checksum for received skb after pull

 *	@skb: buffer to update
@@ -2857,36 +2869,38 @@ static inline int skb_linearize_cow(struct sk_buff *skb) 
 *	update the CHECKSUM_COMPLETE checksum, or set ip_summed to

 *	CHECKSUM_NONE so that it can be recomputed from scratch.

 */



static inline void skb_postpull_rcsum(struct sk_buff *skb,

				      const void *start, unsigned int len)

{

	if (skb->ip_summed == CHECKSUM_COMPLETE)

		skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));

	else if (skb->ip_summed == CHECKSUM_PARTIAL &&

		 skb_checksum_start_offset(skb) < 0)

		skb->ip_summed = CHECKSUM_NONE;

	__skb_postpull_rcsum(skb, start, len, 0);

}



unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);

static __always_inline void

__skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,

		     unsigned int off)

{

	if (skb->ip_summed == CHECKSUM_COMPLETE)

		skb->csum = csum_block_add(skb->csum,

					   csum_partial(start, len, 0), off);

}



/**

 *	skb_postpush_rcsum - update checksum for received skb after push

 *	@skb: buffer to update

 *	@start: start of data after push

 *	@len: length of data pushed

 *

 *	After doing a push on a received packet, you need to call this to

 *	update the CHECKSUM_COMPLETE checksum.

 */

static inline void skb_postpush_rcsum(struct sk_buff *skb,

				      const void *start, unsigned int len)

{

	/* For performing the reverse operation to skb_postpull_rcsum(),

	 * we can instead of ...

	 *

	 *   skb->csum = csum_add(skb->csum, csum_partial(start, len, 0));

	 *

	 * ... just use this equivalent version here to save a few

	 * instructions. Feeding csum of 0 in csum_partial() and later

	 * on adding skb->csum is equivalent to feed skb->csum in the

	 * first place.

	 */

	if (skb->ip_summed == CHECKSUM_COMPLETE)

		skb->csum = csum_partial(start, len, skb->csum);

	__skb_postpush_rcsum(skb, start, len, 0);

}



unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);



/**

 *	skb_push_rcsum - push skb and update receive checksum

 *	@skb: buffer to update

net/core/filter.c

+24 −5
Original line number Diff line number Diff line
@@ -1365,6 +1365,18 @@ static inline int bpf_try_make_writable(struct sk_buff *skb, 
	return err;

}



static inline void bpf_push_mac_rcsum(struct sk_buff *skb)

{

	if (skb_at_tc_ingress(skb))

		skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);

}



static inline void bpf_pull_mac_rcsum(struct sk_buff *skb)

{

	if (skb_at_tc_ingress(skb))

		skb_postpull_rcsum(skb, skb_mac_header(skb), skb->mac_len);

}



static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)

{

	struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp);
@@ -1395,7 +1407,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) 
		return -EFAULT;



	if (flags & BPF_F_RECOMPUTE_CSUM)

		skb_postpull_rcsum(skb, ptr, len);

		__skb_postpull_rcsum(skb, ptr, len, offset);



	memcpy(ptr, from, len);
@@ -1404,7 +1416,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) 
		skb_store_bits(skb, offset, ptr, len);



	if (flags & BPF_F_RECOMPUTE_CSUM)

		skb_postpush_rcsum(skb, ptr, len);

		__skb_postpush_rcsum(skb, ptr, len, offset);

	if (flags & BPF_F_INVALIDATE_HASH)

		skb_clear_hash(skb);
@@ -1607,9 +1619,6 @@ static const struct bpf_func_proto bpf_csum_diff_proto = { 


static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb)

{

	if (skb_at_tc_ingress(skb))

		skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);



	return dev_forward_skb(dev, skb);

}
@@ -1648,6 +1657,8 @@ static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) 
	if (unlikely(!skb))

		return -ENOMEM;



	bpf_push_mac_rcsum(skb);



	return flags & BPF_F_INGRESS ?

	       __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);

}
@@ -1693,6 +1704,8 @@ int skb_do_redirect(struct sk_buff *skb) 
		return -EINVAL;

	}



	bpf_push_mac_rcsum(skb);



	return ri->flags & BPF_F_INGRESS ?

	       __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);

}
@@ -1756,7 +1769,10 @@ static u64 bpf_skb_vlan_push(u64 r1, u64 r2, u64 vlan_tci, u64 r4, u64 r5) 
		     vlan_proto != htons(ETH_P_8021AD)))

		vlan_proto = htons(ETH_P_8021Q);



	bpf_push_mac_rcsum(skb);

	ret = skb_vlan_push(skb, vlan_proto, vlan_tci);

	bpf_pull_mac_rcsum(skb);



	bpf_compute_data_end(skb);

	return ret;

}
@@ -1776,7 +1792,10 @@ static u64 bpf_skb_vlan_pop(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) 
	struct sk_buff *skb = (struct sk_buff *) (long) r1;

	int ret;



	bpf_push_mac_rcsum(skb);

	ret = skb_vlan_pop(skb);

	bpf_pull_mac_rcsum(skb);



	bpf_compute_data_end(skb);

	return ret;

}