[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/udp.c b/net/ipv6/udp.c
index bf95193..e671153 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -248,7 +248,7 @@
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
} else if (msg->msg_flags&MSG_TRUNC) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
+ if (__skb_checksum_complete(skb))
goto csum_copy_err;
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
@@ -363,13 +363,10 @@
return -1;
}
- if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
- UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return 0;
- }
- skb->ip_summed = CHECKSUM_UNNECESSARY;
+ if (skb_checksum_complete(skb)) {
+ UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
+ kfree_skb(skb);
+ return 0;
}
if (sock_queue_rcv_skb(sk,skb)<0) {
@@ -491,13 +488,10 @@
uh = skb->h.uh;
}
- if (skb->ip_summed==CHECKSUM_HW) {
+ if (skb->ip_summed == CHECKSUM_HW &&
+ !csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum)) {
- LIMIT_NETDEBUG(KERN_DEBUG "udp v6 hw csum failure.\n");
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
+
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
skb->csum = ~csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, 0);
@@ -521,8 +515,7 @@
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard;
- if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
- (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
+ if (skb_checksum_complete(skb))
goto discard;
UDP6_INC_STATS_BH(UDP_MIB_NOPORTS);