From 759e5d006462d53fb708daa8284b4ad909415da1 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 25 Mar 2007 20:10:56 -0700 Subject: [UDP]: Clean up UDP-Lite receive checksum This patch eliminates some duplicate code for the verification of receive checksums between UDP-Lite and UDP. It does this by introducing __skb_checksum_complete_head which is identical to __skb_checksum_complete_head apart from the fact that it takes a length parameter rather than computing the first skb->len bytes. As a result UDP-Lite will be able to use hardware checksum offload for packets which do not use partial coverage checksums. It also means that UDP-Lite loopback no longer does unnecessary checksum verification. If any NICs start support UDP-Lite this would also start working automatically. This patch removes the assumption that msg_flags has MSG_TRUNC clear upon entry in recvmsg. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + include/net/udp.h | 5 +---- include/net/udplite.h | 39 ++++++--------------------------------- 3 files changed, 8 insertions(+), 37 deletions(-) (limited to 'include') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 30089adb2e7..df229bd5f1a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1372,6 +1372,7 @@ static inline void __net_timestamp(struct sk_buff *skb) } +extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); extern __sum16 __skb_checksum_complete(struct sk_buff *skb); /** diff --git a/include/net/udp.h b/include/net/udp.h index 1b921fa8147..4a9699f7928 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -72,10 +72,7 @@ struct sk_buff; */ static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) { - if (! UDP_SKB_CB(skb)->partial_cov) - return __skb_checksum_complete(skb); - return csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov, - skb->csum)); + return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov); } static inline int udp_lib_checksum_complete(struct sk_buff *skb) diff --git a/include/net/udplite.h b/include/net/udplite.h index 67ac5142430..d99df75fe54 100644 --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -47,11 +47,10 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) return 1; } - UDP_SKB_CB(skb)->partial_cov = 0; cscov = ntohs(uh->len); if (cscov == 0) /* Indicates that full coverage is required. */ - cscov = skb->len; + ; else if (cscov < 8 || cscov > skb->len) { /* * Coverage length violates RFC 3828: log and discard silently. @@ -60,42 +59,16 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) cscov, skb->len); return 1; - } else if (cscov < skb->len) + } else if (cscov < skb->len) { UDP_SKB_CB(skb)->partial_cov = 1; - - UDP_SKB_CB(skb)->cscov = cscov; - - /* - * There is no known NIC manufacturer supporting UDP-Lite yet, - * hence ip_summed is always (re-)set to CHECKSUM_NONE. - */ - skb->ip_summed = CHECKSUM_NONE; + UDP_SKB_CB(skb)->cscov = cscov; + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_NONE; + } return 0; } -static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh) -{ - int rc = udplite_checksum_init(skb, uh); - - if (!rc) - skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, - skb->nh.iph->daddr, - skb->len, IPPROTO_UDPLITE, 0); - return rc; -} - -static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh) -{ - int rc = udplite_checksum_init(skb, uh); - - if (!rc) - skb->csum = ~csum_unfold(csum_ipv6_magic(&skb->nh.ipv6h->saddr, - &skb->nh.ipv6h->daddr, - skb->len, IPPROTO_UDPLITE, 0)); - return rc; -} - static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh) { int cscov = up->len; -- cgit v1.2.3-70-g09d2