[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 <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
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committed by
David S. Miller

parent
1ab6eb62b0
commit
759e5d0064
@@ -47,11 +47,10 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
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return 1;
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}
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UDP_SKB_CB(skb)->partial_cov = 0;
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cscov = ntohs(uh->len);
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if (cscov == 0) /* Indicates that full coverage is required. */
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cscov = skb->len;
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;
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else if (cscov < 8 || cscov > skb->len) {
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/*
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* Coverage length violates RFC 3828: log and discard silently.
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@@ -60,42 +59,16 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
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cscov, skb->len);
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return 1;
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} else if (cscov < skb->len)
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} else if (cscov < skb->len) {
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UDP_SKB_CB(skb)->partial_cov = 1;
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UDP_SKB_CB(skb)->cscov = cscov;
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/*
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* There is no known NIC manufacturer supporting UDP-Lite yet,
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* hence ip_summed is always (re-)set to CHECKSUM_NONE.
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*/
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skb->ip_summed = CHECKSUM_NONE;
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UDP_SKB_CB(skb)->cscov = cscov;
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->ip_summed = CHECKSUM_NONE;
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}
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return 0;
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}
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static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh)
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{
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int rc = udplite_checksum_init(skb, uh);
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if (!rc)
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skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
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skb->nh.iph->daddr,
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skb->len, IPPROTO_UDPLITE, 0);
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return rc;
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}
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static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh)
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{
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int rc = udplite_checksum_init(skb, uh);
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if (!rc)
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skb->csum = ~csum_unfold(csum_ipv6_magic(&skb->nh.ipv6h->saddr,
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&skb->nh.ipv6h->daddr,
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skb->len, IPPROTO_UDPLITE, 0));
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return rc;
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}
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static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
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{
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int cscov = up->len;
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