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[NET]: Detect hardware rx checksum faults correctly

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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>
This commit is contained in:
Herbert Xu
2005-11-10 13:01:24 -08:00
committed by David S. Miller
parent 1064e944d0
commit fb286bb299
19 changed files with 173 additions and 134 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
net/core/datagram.c
View File

@@ -350,6 +350,20 @@ fault:
return -EFAULT;
}
unsigned int __skb_checksum_complete(struct sk_buff *skb)
{
unsigned int sum;
sum = (u16)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
if (likely(!sum)) {
if (unlikely(skb->ip_summed == CHECKSUM_HW))
netdev_rx_csum_fault(skb->dev);
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
return sum;
}
EXPORT_SYMBOL(__skb_checksum_complete);
/**
* skb_copy_and_csum_datagram_iovec - Copy and checkum skb to user iovec.
* @skb: skbuff
@@ -363,7 +377,7 @@ fault:
* -EFAULT - fault during copy. Beware, in this case iovec
* can be modified!
*/
int skb_copy_and_csum_datagram_iovec(const struct sk_buff *skb,
int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
int hlen, struct iovec *iov)
{
unsigned int csum;
@@ -376,8 +390,7 @@ int skb_copy_and_csum_datagram_iovec(const struct sk_buff *skb,
iov++;
if (iov->iov_len < chunk) {
if ((unsigned short)csum_fold(skb_checksum(skb, 0, chunk + hlen,
skb->csum)))
if (__skb_checksum_complete(skb))
goto csum_error;
if (skb_copy_datagram_iovec(skb, hlen, iov, chunk))
goto fault;
@@ -388,6 +401,8 @@ int skb_copy_and_csum_datagram_iovec(const struct sk_buff *skb,
goto fault;
if ((unsigned short)csum_fold(csum))
goto csum_error;
if (unlikely(skb->ip_summed == CHECKSUM_HW))
netdev_rx_csum_fault(skb->dev);
iov->iov_len -= chunk;
iov->iov_base += chunk;
}

12
net/core/dev.c
View File

@@ -1108,6 +1108,18 @@ out:
return ret;
}
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
if (net_ratelimit()) {
printk(KERN_ERR "%s: hw csum failure.\n", dev->name);
dump_stack();
}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif
#ifdef CONFIG_HIGHMEM
/* Actually, we should eliminate this check as soon as we know, that:
* 1. IOMMU is present and allows to map all the memory.

18
net/core/netpoll.c
View File

@@ -101,16 +101,20 @@ void netpoll_queue(struct sk_buff *skb)
static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, u32 saddr, u32 daddr)
{
if (uh->check == 0)
unsigned int psum;
if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
return 0;
if (skb->ip_summed == CHECKSUM_HW)
return csum_tcpudp_magic(
saddr, daddr, ulen, IPPROTO_UDP, skb->csum);
psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
if (skb->ip_summed == CHECKSUM_HW &&
!(u16)csum_fold(csum_add(psum, skb->csum)))
return 0;
return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
skb->csum = psum;
return __skb_checksum_complete(skb);
}
/*
@@ -489,7 +493,7 @@ int __netpoll_rx(struct sk_buff *skb)
if (ulen != len)
goto out;
if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr) < 0)
if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
goto out;
if (np->local_ip && np->local_ip != ntohl(iph->daddr))
goto out;