+/**
+ * @internal Calculate the non-complemented IPv6 L4 checksum of a packet
+ */
+static inline uint16_t
+__rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+ const struct rte_ipv6_hdr *ipv6_hdr,
+ uint16_t l4_off)
+{
+ uint16_t raw_cksum;
+ uint32_t cksum;
+
+ if (l4_off > m->pkt_len)
+ return 0;
+
+ if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
+ return 0;
+
+ cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
+
+ cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
+
+ return (uint16_t)cksum;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Process the IPv6 UDP or TCP checksum of a packet.
+ *
+ * The IPv6 header must not be followed by extension headers. The layer 4
+ * checksum must be set to 0 in the L4 header by the caller.
+ *
+ * @param m
+ * The pointer to the mbuf.
+ * @param ipv6_hdr
+ * The pointer to the contiguous IPv6 header.
+ * @param l4_off
+ * The offset in bytes to start L4 checksum.
+ * @return
+ * The complemented checksum to set in the L4 header.
+ */
+__rte_experimental
+static inline uint16_t
+rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+ const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
+{
+ uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
+
+ cksum = ~cksum;
+
+ /*
+ * Per RFC 768: If the computed checksum is zero for UDP,
+ * it is transmitted as all ones
+ * (the equivalent in one's complement arithmetic).
+ */
+ if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
+ cksum = 0xffff;
+
+ return cksum;
+}
+