nat_ipv6_addrs_delta(struct in6_addr *ipv6_aligned_min,
                     struct in6_addr *ipv6_aligned_max)
{
    uint8_t *ipv6_min_hi = &ipv6_aligned_min->s6_addr[0];
    uint8_t *ipv6_min_lo = &ipv6_aligned_min->s6_addr[0] +  sizeof(uint64_t);
    uint8_t *ipv6_max_hi = &ipv6_aligned_max->s6_addr[0];
    uint8_t *ipv6_max_lo = &ipv6_aligned_max->s6_addr[0] + sizeof(uint64_t);

    ovs_be64 addr6_64_min_hi;
    ovs_be64 addr6_64_min_lo;
    memcpy(&addr6_64_min_hi, ipv6_min_hi, sizeof addr6_64_min_hi);
    memcpy(&addr6_64_min_lo, ipv6_min_lo, sizeof addr6_64_min_lo);

    ovs_be64 addr6_64_max_hi;
    ovs_be64 addr6_64_max_lo;
    memcpy(&addr6_64_max_hi, ipv6_max_hi, sizeof addr6_64_max_hi);
    memcpy(&addr6_64_max_lo, ipv6_max_lo, sizeof addr6_64_max_lo);

    uint64_t diff;

    if (addr6_64_min_hi == addr6_64_max_hi &&
        ntohll(addr6_64_min_lo) <= ntohll(addr6_64_max_lo)) {
        diff = ntohll(addr6_64_max_lo) - ntohll(addr6_64_min_lo);
    } else if (ntohll(addr6_64_min_hi) + 1 == ntohll(addr6_64_max_hi) &&
               ntohll(addr6_64_min_lo) > ntohll(addr6_64_max_lo)) {
        diff = UINT64_MAX - (ntohll(addr6_64_min_lo) -
                             ntohll(addr6_64_max_lo) - 1);
    } else {
        /* Limit address delta supported to 32 bits or 4 billion approximately.
         * Possibly, this should be visible to the user through a datapath
         * support check, however the practical impact is probably nil. */
        diff = 0xfffffffe;
    }

    if (diff > 0xfffffffe) {
        diff = 0xfffffffe;
    }
    return diff;
}
nat_ipv6_addrs_delta(struct in6_addr *ipv6_aligned_min,
                     struct in6_addr *ipv6_aligned_max)
{
    uint8_t *ipv6_min_hi = &ipv6_aligned_min->s6_addr[0];
    uint8_t *ipv6_min_lo = &ipv6_aligned_min->s6_addr[0] +  sizeof(uint64_t);
    uint8_t *ipv6_max_hi = &ipv6_aligned_max->s6_addr[0];
    uint8_t *ipv6_max_lo = &ipv6_aligned_max->s6_addr[0] + sizeof(uint64_t);

    ovs_be64 addr6_64_min_hi;
    ovs_be64 addr6_64_min_lo;
    memcpy(&addr6_64_min_hi, ipv6_min_hi, sizeof addr6_64_min_hi);
    memcpy(&addr6_64_min_lo, ipv6_min_lo, sizeof addr6_64_min_lo);

    ovs_be64 addr6_64_max_hi;
    ovs_be64 addr6_64_max_lo;
    memcpy(&addr6_64_max_hi, ipv6_max_hi, sizeof addr6_64_max_hi);
    memcpy(&addr6_64_max_lo, ipv6_max_lo, sizeof addr6_64_max_lo);

    uint64_t diff;

    if (addr6_64_min_hi == addr6_64_max_hi &&
        ntohll(addr6_64_min_lo) <= ntohll(addr6_64_max_lo)) {
        diff = ntohll(addr6_64_max_lo) - ntohll(addr6_64_min_lo);
    } else if (ntohll(addr6_64_min_hi) + 1 == ntohll(addr6_64_max_hi) &&
               ntohll(addr6_64_min_lo) > ntohll(addr6_64_max_lo)) {
        diff = UINT64_MAX - (ntohll(addr6_64_min_lo) -
                             ntohll(addr6_64_max_lo) - 1);
    } else {
         
        diff = 0xfffffffe;
    }

    if (diff > 0xfffffffe) {
        diff = 0xfffffffe;
    }
    return diff;
}