[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>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 896ce3f..4e9c74b 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -577,15 +577,16 @@
goto drop_nolock;
if (flags&GRE_CSUM) {
- if (skb->ip_summed == CHECKSUM_HW) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
csum = (u16)csum_fold(skb->csum);
- if (csum)
- skb->ip_summed = CHECKSUM_NONE;
- }
- if (skb->ip_summed == CHECKSUM_NONE) {
- skb->csum = skb_checksum(skb, 0, skb->len, 0);
+ if (!csum)
+ break;
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = 0;
+ csum = __skb_checksum_complete(skb);
skb->ip_summed = CHECKSUM_HW;
- csum = (u16)csum_fold(skb->csum);
}
offset += 4;
}