1 files changed, 90 insertions, 0 deletions
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
new file mode 100644
index 000000000..e1a594873
--- /dev/null
+++ b/net/ipv6/ip6_checksum.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <net/ip.h>
+#include <net/ip6_checksum.h>
+#include <net/udp.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, __u8 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
+
+/* 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->ip_summed == CHECKSUM_PARTIAL) {
+		uh->check = 0;
+		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+	} else {
+		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);
+	}
+}
+EXPORT_SYMBOL(udp6_set_csum);