How to calculate ICMPv6 checksum?

[Gábor LENCSE]

Dear All,

I am working on adding ARP/NDP support to my SIIT / Stateful NAT64 
benchmarking tool, siitperf [1]. (So far, the ARP / NDP table entries 
had to be set manually at the device under test, as siitperf was not 
able to reply to ARP / NDP requests).

The ARP reply functionality seems to work fine, but I have a problem 
with NDP. As ICMPv6 messages contain checksum, I would need a function 
that computes it. However, I only found  the rte_ipv6_udptcp_cksum() 
function, but I did not find a similar one for calculating ICMPv6 checksum.

I have been checking the functions shown here: 
https://doc.dpdk.org/api/rte__ip6_8h.html

Could you please advise me about the function to use for ICMPv6 checksum 
calculation?

Best regards,

Gábor

[1] https://github.com/lencsegabor/siitperf