Commit ede57d58 authored by Richard Gobert's avatar Richard Gobert Committed by Jakub Kicinski
Browse files

net: helper function skb_len_add 



Move the len fields manipulation in the skbs to a helper function.
There is a comment specifically requesting this and there are several
other areas in the code displaying the same pattern which can be
refactored.
This improves code readability.

Signed-off-by: default avatarRichard Gobert <richardbgobert@gmail.com>
Link: https://lore.kernel.org/r/20220622160853.GA6478@debian


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1da9e274

include/linux/skbuff.h

+12 −0
Original line number Diff line number Diff line
@@ -2351,6 +2351,18 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb) 
	return skb_headlen(skb) + __skb_pagelen(skb);

}



/**

 * skb_len_add - adds a number to len fields of skb

 * @skb: buffer to add len to

 * @delta: number of bytes to add

 */

static inline void skb_len_add(struct sk_buff *skb, int delta)

{

	skb->len += delta;

	skb->data_len += delta;

	skb->truesize += delta;

}



/**

 * __skb_fill_page_desc - initialise a paged fragment in an skb

 * @skb: buffer containing fragment to be initialised

include/net/sock.h

+1 −3
Original line number Diff line number Diff line
@@ -2219,9 +2219,7 @@ static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *fro 
	if (err)

		return err;



	skb->len	     += copy;

	skb->data_len	     += copy;

	skb->truesize	     += copy;

	skb_len_add(skb, copy);

	sk_wmem_queued_add(sk, copy);

	sk_mem_charge(sk, copy);

	return 0;

net/core/skbuff.c

+3 −10
Original line number Diff line number Diff line
@@ -3195,9 +3195,7 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) 
		}

	}



	to->truesize += len + plen;

	to->len += len + plen;

	to->data_len += len + plen;

	skb_len_add(to, len + plen);



	if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {

		skb_tx_error(from);
@@ -3634,13 +3632,8 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) 
	tgt->ip_summed = CHECKSUM_PARTIAL;

	skb->ip_summed = CHECKSUM_PARTIAL;



	/* Yak, is it really working this way? Some helper please? */

	skb->len -= shiftlen;

	skb->data_len -= shiftlen;

	skb->truesize -= shiftlen;

	tgt->len += shiftlen;

	tgt->data_len += shiftlen;

	tgt->truesize += shiftlen;

	skb_len_add(skb, -shiftlen);

	skb_len_add(tgt, shiftlen);



	return shiftlen;

}

net/ipv4/esp4.c

+1 −3
Original line number Diff line number Diff line
@@ -502,9 +502,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * 


			nfrags++;



			skb->len += tailen;

			skb->data_len += tailen;

			skb->truesize += tailen;

			skb_len_add(skb, tailen);

			if (sk && sk_fullsock(sk))

				refcount_add(tailen, &sk->sk_wmem_alloc);

net/ipv4/ip_output.c

+2 −6
Original line number Diff line number Diff line
@@ -1214,9 +1214,7 @@ static int __ip_append_data(struct sock *sk, 


			pfrag->offset += copy;

			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);

			skb->len += copy;

			skb->data_len += copy;

			skb->truesize += copy;

			skb_len_add(skb, copy);

			wmem_alloc_delta += copy;

		} else {

			err = skb_zerocopy_iter_dgram(skb, from, copy);
@@ -1443,9 +1441,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 
			skb->csum = csum_block_add(skb->csum, csum, skb->len);

		}



		skb->len += len;

		skb->data_len += len;

		skb->truesize += len;

		skb_len_add(skb, len);

		refcount_add(len, &sk->sk_wmem_alloc);

		offset += len;

		size -= len;