From cbb042f9e1292434e3cacb90e67d8d381aeac5a9 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 20 Mar 2006 22:43:56 -0800 Subject: [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 Signed-off-by: David S. Miller --- net/core/skbuff.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'net/core') 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", -- cgit v1.2.2