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author | Jean Delvare <jdelvare@suse.de> | 2007-04-26 09:44:22 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-04-26 09:44:22 +0200 |
commit | eefa3906283a2b60a6d02a2cda593a7d7d7946c5 (patch) | |
tree | a4e1f3b8dca04b8dff3cd99dc43f771f798558fb /net/xfrm/xfrm_algo.c | |
parent | [XFRM]: Export SAD info. (diff) | |
download | linux-eefa3906283a2b60a6d02a2cda593a7d7d7946c5.tar.xz linux-eefa3906283a2b60a6d02a2cda593a7d7d7946c5.zip |
[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.c | 22 |
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); |