[NET]: Detect hardware rx checksum faults correctly

Here is the patch that introduces the generic skb_checksum_complete
which also checks for hardware RX checksum faults.  If that happens,
it'll call netdev_rx_csum_fault which currently prints out a stack
trace with the device name.  In future it can turn off RX checksum.

I've converted every spot under net/ that does RX checksum checks to
use skb_checksum_complete or __skb_checksum_complete with the
exceptions of:

* Those places where checksums are done bit by bit.  These will call
netdev_rx_csum_fault directly.

* The following have not been completely checked/converted:

ipmr
ip_vs
netfilter
dccp

This patch is based on patches and suggestions from Stephen Hemminger
and David S. Miller.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 8f97e90f36c8..eb330d4f66d6 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -6,6 +6,9 @@
  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  */
 
+#include <linux/compiler.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
 #include <linux/types.h>
 #include <linux/pagemap.h>
 #include <linux/udp.h>
@@ -165,6 +168,8 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
                 return -1;
         if ((unsigned short)csum_fold(desc.csum))
                 return -1;
+        if (unlikely(skb->ip_summed == CHECKSUM_HW))
+                netdev_rx_csum_fault(skb->dev);
         return 0;
 no_checksum:
         if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits) < 0)