[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/ipv6/icmp.c b/net/ipv6/icmp.c
index 23e5403..1bdf0fb 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -585,17 +585,16 @@
daddr = &skb->nh.ipv6h->daddr;
/* Perform checksum. */
- if (skb->ip_summed == CHECKSUM_HW) {
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
- skb->csum)) {
- LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 hw checksum failed\n");
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
- if (skb->ip_summed == CHECKSUM_NONE) {
- if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
- skb_checksum(skb, 0, skb->len, 0))) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
+ skb->csum))
+ break;
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = ~csum_ipv6_magic(saddr, daddr, skb->len,
+ IPPROTO_ICMPV6, 0);
+ if (__skb_checksum_complete(skb)) {
LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x > %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]\n",
NIP6(*saddr), NIP6(*daddr));
goto discard_it;