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author | Herbert Xu <herbert@gondor.apana.org.au> | 2006-03-21 07:43:56 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2006-03-21 07:43:56 +0100 |
commit | cbb042f9e1292434e3cacb90e67d8d381aeac5a9 (patch) | |
tree | cc42f42232e56b68111cfebdc175197d8607bdd7 /net/core | |
parent | [DECnet]: Use RCU locking in dn_rules.c (diff) | |
download | linux-cbb042f9e1292434e3cacb90e67d8d381aeac5a9.tar.xz linux-cbb042f9e1292434e3cacb90e67d8d381aeac5a9.zip |
[NET]: Replace skb_pull/skb_postpull_rcsum with skb_pull_rcsum
We're now starting to have quite a number of places that do skb_pull
followed immediately by an skb_postpull_rcsum. We can merge these two
operations into one function with skb_pull_rcsum. This makes sense
since most pull operations on receive skb's need to update the
checksum.
I've decided to make this out-of-line since it is fairly big and the
fast path where hardware checksums are enabled need to call
csum_partial anyway.
Since this is a brand new function we get to add an extra check on the
len argument. As it is most callers of skb_pull ignore its return
value which essentially means that there is no check on the len
argument.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/skbuff.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 01abf1e8990b..2960c8b82b23 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1795,6 +1795,27 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, return 0; } +/** + * skb_pull_rcsum - pull skb and update receive checksum + * @skb: buffer to update + * @start: start of data before pull + * @len: length of data pulled + * + * This function performs an skb_pull on the packet and updates + * update the CHECKSUM_HW checksum. It should be used on receive + * path processing instead of skb_pull unless you know that the + * checksum difference is zero (e.g., a valid IP header) or you + * are setting ip_summed to CHECKSUM_NONE. + */ +unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) +{ + BUG_ON(len > skb->len); + skb->len -= len; + BUG_ON(skb->len < skb->data_len); + skb_postpull_rcsum(skb, skb->data, len); + return skb->data += len; +} + void __init skb_init(void) { skbuff_head_cache = kmem_cache_create("skbuff_head_cache", |