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Diffstat (limited to 'net/ipv6/ip6_checksum.c')
-rw-r--r--net/ipv6/ip6_checksum.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
new file mode 100644
index 000000000000..72d198b8e4d2
--- /dev/null
+++ b/net/ipv6/ip6_checksum.c
@@ -0,0 +1,97 @@
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <asm/checksum.h>
+
+#ifndef _HAVE_ARCH_IPV6_CSUM
+__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __u32 len, unsigned short proto,
+ __wsum csum)
+{
+
+ int carry;
+ __u32 ulen;
+ __u32 uproto;
+ __u32 sum = (__force u32)csum;
+
+ sum += (__force u32)saddr->s6_addr32[0];
+ carry = (sum < (__force u32)saddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[1];
+ carry = (sum < (__force u32)saddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[2];
+ carry = (sum < (__force u32)saddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[3];
+ carry = (sum < (__force u32)saddr->s6_addr32[3]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[0];
+ carry = (sum < (__force u32)daddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[1];
+ carry = (sum < (__force u32)daddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[2];
+ carry = (sum < (__force u32)daddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[3];
+ carry = (sum < (__force u32)daddr->s6_addr32[3]);
+ sum += carry;
+
+ ulen = (__force u32)htonl((__u32) len);
+ sum += ulen;
+ carry = (sum < ulen);
+ sum += carry;
+
+ uproto = (__force u32)htonl(proto);
+ sum += uproto;
+ carry = (sum < uproto);
+ sum += carry;
+
+ return csum_fold((__force __wsum)sum);
+}
+EXPORT_SYMBOL(csum_ipv6_magic);
+#endif
+
+int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
+{
+ int err;
+
+ UDP_SKB_CB(skb)->partial_cov = 0;
+ UDP_SKB_CB(skb)->cscov = skb->len;
+
+ if (proto == IPPROTO_UDPLITE) {
+ err = udplite_checksum_init(skb, uh);
+ if (err)
+ return err;
+ }
+
+ if (uh->check == 0) {
+ /* RFC 2460 section 8.1 says that we SHOULD log
+ this error. Well, it is reasonable.
+ */
+ LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
+ return 1;
+ }
+ if (skb->ip_summed == CHECKSUM_COMPLETE &&
+ !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
+ skb->len, proto, skb->csum))
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ if (!skb_csum_unnecessary(skb))
+ skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr,
+ skb->len, proto, 0));
+
+ return 0;
+}
+EXPORT_SYMBOL(udp6_csum_init);