[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/igmp.c b/net/ipv4/igmp.c
index c6247fc..c04607b 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -872,11 +872,18 @@
return 0;
}
- if (!pskb_may_pull(skb, sizeof(struct igmphdr)) ||
- (u16)csum_fold(skb_checksum(skb, 0, len, 0))) {
- in_dev_put(in_dev);
- kfree_skb(skb);
- return 0;
+ if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
+ goto drop;
+
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (!(u16)csum_fold(skb->csum))
+ break;
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = 0;
+ if (__skb_checksum_complete(skb))
+ goto drop;
}
ih = skb->h.igmph;
@@ -906,6 +913,8 @@
default:
NETDEBUG(KERN_DEBUG "New IGMP type=%d, why we do not know about it?\n", ih->type);
}
+
+drop:
in_dev_put(in_dev);
kfree_skb(skb);
return 0;