From 7ce5a27f2ef8ed4f8f892f46391f933c0e2ac0f1 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Mon, 2 Dec 2013 17:26:05 -0500
Subject: [PATCH] Revert "net: Handle CHECKSUM_COMPLETE more adequately in
pskb_trim_rcsum()."
This reverts commit 018c5bba052b3a383d83cf0c756da0e7bc748397.
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>
---
include/linux/skbuff.h | 39 ++++++++++++++++++---------------------
1 file changed, 18 insertions(+), 21 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bec1cc7d5e3c..215b5ea1cb30 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -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)
{
--
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