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 --- include/linux/skbuff.h | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 83010231db9..0a8ea8b3581 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1236,8 +1236,7 @@ extern unsigned int datagram_poll(struct file *file, struct socket *sock, extern int skb_copy_datagram_iovec(const struct sk_buff *from, int offset, struct iovec *to, int size); -extern int skb_copy_and_csum_datagram_iovec(const - struct sk_buff *skb, +extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen, struct iovec *iov); extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); @@ -1305,6 +1304,30 @@ static inline void skb_set_timestamp(struct sk_buff *skb, const struct timeval * extern void __net_timestamp(struct sk_buff *skb); +extern unsigned int __skb_checksum_complete(struct sk_buff *skb); + +/** + * skb_checksum_complete - Calculate checksum of an entire packet + * @skb: packet to process + * + * This function calculates the checksum over the entire packet plus + * the value of skb->csum. The latter can be used to supply the + * checksum of a pseudo header as used by TCP/UDP. It returns the + * checksum. + * + * For protocols that contain complete checksums such as ICMP/TCP/UDP, + * this function can be used to verify that checksum on received + * packets. In that case the function should return zero if the + * checksum is correct. In particular, this function will return zero + * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the + * hardware has already verified the correctness of the checksum. + */ +static inline unsigned int skb_checksum_complete(struct sk_buff *skb) +{ + return skb->ip_summed != CHECKSUM_UNNECESSARY && + __skb_checksum_complete(skb); +} + #ifdef CONFIG_NETFILTER static inline void nf_conntrack_put(struct nf_conntrack *nfct) { -- cgit v1.2.2