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authorJean Delvare <jdelvare@suse.de>2007-04-26 00:44:22 -0700
committerDavid S. Miller <davem@davemloft.net>2007-04-26 00:44:22 -0700
commiteefa3906283a2b60a6d02a2cda593a7d7d7946c5 (patch)
treea4e1f3b8dca04b8dff3cd99dc43f771f798558fb /net/xfrm/xfrm_algo.c
parent28d8909bc790d936ce33f4402adf7577533bbd4b (diff)
downloadkernel-eefa3906283a2b60a6d02a2cda593a7d7d7946c5.tar.gz
[NET]: Clean up sk_buff walkers.
I noticed recently that, in skb_checksum(), "offset" and "start" are essentially the same thing and have the same value throughout the function, despite being computed differently. Using a single variable allows some cleanups and makes the skb_checksum() function smaller, more readable, and presumably marginally faster. We appear to have many other "sk_buff walker" functions built on the exact same model, so the cleanup applies to them, too. Here is a list of the functions I found to be affected: net/appletalk/ddp.c:atalk_sum_skb() net/core/datagram.c:skb_copy_datagram_iovec() net/core/datagram.c:skb_copy_and_csum_datagram() net/core/skbuff.c:skb_copy_bits() net/core/skbuff.c:skb_store_bits() net/core/skbuff.c:skb_checksum() net/core/skbuff.c:skb_copy_and_csum_bit() net/core/user_dma.c:dma_skb_copy_datagram_iovec() net/xfrm/xfrm_algo.c:skb_icv_walk() net/xfrm/xfrm_algo.c:skb_to_sgvec() OTOH, I admit I'm a bit surprised, the cleanup is rather obvious so I'm really wondering if I am missing something. Can anyone please comment on this? Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/xfrm/xfrm_algo.c')
-rw-r--r--net/xfrm/xfrm_algo.c22
1 files changed, 8 insertions, 14 deletions
diff --git a/net/xfrm/xfrm_algo.c b/net/xfrm/xfrm_algo.c
index 6249a9405bb8..be529c4241a6 100644
--- a/net/xfrm/xfrm_algo.c
+++ b/net/xfrm/xfrm_algo.c
@@ -532,8 +532,8 @@ EXPORT_SYMBOL_GPL(xfrm_count_enc_supported);
int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
int offset, int len, icv_update_fn_t icv_update)
{
- int start = skb_headlen(skb);
- int i, copy = start - offset;
+ int end = skb_headlen(skb);
+ int i, copy = end - offset;
int err;
struct scatterlist sg;
@@ -556,11 +556,9 @@ int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int end;
+ BUG_TRAP(len >= 0);
- BUG_TRAP(start <= offset + len);
-
- end = start + skb_shinfo(skb)->frags[i].size;
+ end = offset + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
@@ -568,7 +566,7 @@ int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
copy = len;
sg.page = frag->page;
- sg.offset = frag->page_offset + offset-start;
+ sg.offset = frag->page_offset;
sg.length = copy;
err = icv_update(desc, &sg, copy);
@@ -579,22 +577,19 @@ int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
return 0;
offset += copy;
}
- start = end;
}
if (skb_shinfo(skb)->frag_list) {
struct sk_buff *list = skb_shinfo(skb)->frag_list;
for (; list; list = list->next) {
- int end;
-
- BUG_TRAP(start <= offset + len);
+ BUG_TRAP(len >= 0);
- end = start + list->len;
+ end = offset + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- err = skb_icv_walk(list, desc, offset-start,
+ err = skb_icv_walk(list, desc, 0,
copy, icv_update);
if (unlikely(err))
return err;
@@ -602,7 +597,6 @@ int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
return 0;
offset += copy;
}
- start = end;
}
}
BUG_ON(len);