net: add skb frag size accessors

To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.

Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 9 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 67a477b..c74548a 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -543,7 +543,7 @@ static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
 		} else {
 			size = min(length, (unsigned) PAGE_SIZE);
 
-			frag->size = size;
+			skb_frag_size_set(frag, size);
 			skb->data_len += size;
 			skb->truesize += size;
 			skb->len += size;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 00435be..2b060f4 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -117,7 +117,7 @@ static void ipoib_ud_skb_put_frags(struct ipoib_dev_priv *priv,
 
 		size = length - IPOIB_UD_HEAD_SIZE;
 
-		frag->size     = size;
+		skb_frag_size_set(frag, size);
 		skb->data_len += size;
 		skb->truesize += size;
 	} else
@@ -322,10 +322,10 @@ static int ipoib_dma_map_tx(struct ib_device *ca,
 		off = 0;
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 		mapping[i + off] = ib_dma_map_page(ca,
 						 skb_frag_page(frag),
-						 frag->page_offset, frag->size,
+						 frag->page_offset, skb_frag_size(frag),
 						 DMA_TO_DEVICE);
 		if (unlikely(ib_dma_mapping_error(ca, mapping[i + off])))
 			goto partial_error;
@@ -334,8 +334,9 @@ static int ipoib_dma_map_tx(struct ib_device *ca,
 
 partial_error:
 	for (; i > 0; --i) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
-		ib_dma_unmap_page(ca, mapping[i - !off], frag->size, DMA_TO_DEVICE);
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
+
+		ib_dma_unmap_page(ca, mapping[i - !off], skb_frag_size(frag), DMA_TO_DEVICE);
 	}
 
 	if (off)
@@ -359,8 +360,9 @@ static void ipoib_dma_unmap_tx(struct ib_device *ca,
 		off = 0;
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
-		ib_dma_unmap_page(ca, mapping[i + off], frag->size,
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+		ib_dma_unmap_page(ca, mapping[i + off], skb_frag_size(frag),
 				  DMA_TO_DEVICE);
 	}
 }
@@ -510,7 +512,7 @@ static inline int post_send(struct ipoib_dev_priv *priv,
 
 	for (i = 0; i < nr_frags; ++i) {
 		priv->tx_sge[i + off].addr = mapping[i + off];
-		priv->tx_sge[i + off].length = frags[i].size;
+		priv->tx_sge[i + off].length = skb_frag_size(&frags[i]);
 	}
 	priv->tx_wr.num_sge	     = nr_frags + off;
 	priv->tx_wr.wr_id 	     = wr_id;