v4.19.13 snapshot.
diff --git a/include/net/ip6_checksum.h b/include/net/ip6_checksum.h
new file mode 100644
index 0000000..cca8405
--- /dev/null
+++ b/include/net/ip6_checksum.h
@@ -0,0 +1,105 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Checksumming functions for IPv6
+ *
+ * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Borrows very liberally from tcp.c and ip.c, see those
+ *		files for more names.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+/*
+ *	Fixes:
+ *
+ *	Ralf Baechle			:	generic ipv6 checksum
+ *	<ralf@waldorf-gmbh.de>
+ */
+
+#ifndef _CHECKSUM_IPV6_H
+#define _CHECKSUM_IPV6_H
+
+#include <asm/types.h>
+#include <asm/byteorder.h>
+#include <net/ip.h>
+#include <asm/checksum.h>
+#include <linux/in6.h>
+#include <linux/tcp.h>
+#include <linux/ipv6.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);
+#endif
+
+static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+					    &ipv6_hdr(skb)->daddr,
+					    skb->len, proto, 0));
+}
+
+static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+
+	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
+					    skb_gro_len(skb), proto, 0));
+}
+
+static __inline__ __sum16 tcp_v6_check(int len,
+				   const struct in6_addr *saddr,
+				   const struct in6_addr *daddr,
+				   __wsum base)
+{
+	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
+}
+
+static inline void __tcp_v6_send_check(struct sk_buff *skb,
+				       const struct in6_addr *saddr,
+				       const struct in6_addr *daddr)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
+		skb->csum_start = skb_transport_header(skb) - skb->head;
+		skb->csum_offset = offsetof(struct tcphdr, check);
+	} else {
+		th->check = tcp_v6_check(skb->len, saddr, daddr,
+					 csum_partial(th, th->doff << 2,
+						      skb->csum));
+	}
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static inline void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
+{
+	struct ipv6_pinfo *np = inet6_sk(sk);
+
+	__tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
+}
+#endif
+
+static inline __sum16 udp_v6_check(int len,
+				   const struct in6_addr *saddr,
+				   const struct in6_addr *daddr,
+				   __wsum base)
+{
+	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base);
+}
+
+void udp6_set_csum(bool nocheck, struct sk_buff *skb,
+		   const struct in6_addr *saddr,
+		   const struct in6_addr *daddr, int len);
+
+int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
+#endif