Revert "net: Handle CHECKSUM_COMPLETE more adequately in pskb_trim_rcsum()."

This reverts commit 018c5bba05.

It causes regressions for people using chips driven by the sungem
driver.  Suspicion is that the skb->csum value isn't being adjusted
properly.

The change also has a bug in that if __pskb_trim() fails, we'll leave
a corruped skb->csum value in there.  We would really need to revert
it to it's original value in that case.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2013-12-02 17:26:05 -05:00
parent 28e24c62ab
commit 7ce5a27f2e

View file

@ -2263,6 +2263,24 @@ static inline void skb_postpull_rcsum(struct sk_buff *skb,
unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
/**
* pskb_trim_rcsum - trim received skb and update checksum
* @skb: buffer to trim
* @len: new length
*
* This is exactly the same as pskb_trim except that it ensures the
* checksum of received packets are still valid after the operation.
*/
static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
{
if (likely(len >= skb->len))
return 0;
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
return __pskb_trim(skb, len);
}
#define skb_queue_walk(queue, skb) \
for (skb = (queue)->next; \
skb != (struct sk_buff *)(queue); \
@ -2360,27 +2378,6 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum csum);
/**
* pskb_trim_rcsum - trim received skb and update checksum
* @skb: buffer to trim
* @len: new length
*
* This is exactly the same as pskb_trim except that it ensures the
* checksum of received packets are still valid after the operation.
*/
static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
{
if (likely(len >= skb->len))
return 0;
if (skb->ip_summed == CHECKSUM_COMPLETE) {
__wsum adj = skb_checksum(skb, len, skb->len - len, 0);
skb->csum = csum_sub(skb->csum, adj);
}
return __pskb_trim(skb, len);
}
static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
int len, void *buffer)
{