From fb286bb2990a107009dbf25f6ffebeb7df77f9be Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 10 Nov 2005 13:01:24 -0800 Subject: [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 Signed-off-by: David S. Miller --- net/core/datagram.c | 21 ++++++++++++++++++--- net/core/dev.c | 12 ++++++++++++ net/core/netpoll.c | 18 +++++++++++------- 3 files changed, 41 insertions(+), 10 deletions(-) (limited to 'net/core') diff --git a/net/core/datagram.c b/net/core/datagram.c index d219435d086..1bcfef51ac5 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -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; } diff --git a/net/core/dev.c b/net/core/dev.c index 8d154159527..0b48e294aaf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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. diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 802fe11efad..49424a42a2c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -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); + + if (skb->ip_summed == CHECKSUM_HW && + !(u16)csum_fold(csum_add(psum, skb->csum))) + return 0; - skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); + skb->csum = psum; - return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)); + 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; -- cgit v1.2.3