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Diffstat (limited to 'net/ipv6/ip6_checksum.c')
-rw-r--r--net/ipv6/ip6_checksum.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
new file mode 100644
index 000000000..9a4d7322f
--- /dev/null
+++ b/net/ipv6/ip6_checksum.c
@@ -0,0 +1,124 @@
+#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;
+ }
+
+ /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
+ * we accept a checksum of zero here. When we find the socket
+ * for the UDP packet we'll check if that socket allows zero checksum
+ * for IPv6 (set by socket option).
+ */
+ return skb_checksum_init_zero_check(skb, proto, uh->check,
+ ip6_compute_pseudo);
+}
+EXPORT_SYMBOL(udp6_csum_init);
+
+/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
+ * for the simple case like when setting the checksum for a UDP tunnel.
+ */
+void udp6_set_csum(bool nocheck, struct sk_buff *skb,
+ const struct in6_addr *saddr,
+ const struct in6_addr *daddr, int len)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (nocheck)
+ uh->check = 0;
+ else if (skb_is_gso(skb))
+ uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+ else if (skb_dst(skb) && skb_dst(skb)->dev &&
+ (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
+
+ BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
+
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+ } else {
+ __wsum csum;
+
+ BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
+
+ uh->check = 0;
+ csum = skb_checksum(skb, 0, len, 0);
+ uh->check = udp_v6_check(len, saddr, daddr, csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ }
+}
+EXPORT_SYMBOL(udp6_set_csum);