Have been working on simulating "Router Advertisement" in OVS for certain requests, for that I constructed a ICMPv6 pkt with all the fields correct except the checksum, wireshark gives an error on the checksum part.
ICMP6 checksum should include src + dst + icmp_length + next_header
but following code is calculating incorrectly.
Am I missing something ? appreciate the help guys.
struct nd_router_advert *ra;
struct ofpbuf *ra_rsp;
struct ovs_16aligned_ip6_hdr *nh;
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ofpbuf_set_l3(ra_rsp, nh);
nh->ip6_vfc = 0x60;
nh->ip6_plen = htons(sizeof(*ra));
nh->ip6_nxt = IPPROTO_ICMPV6;
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ofpbuf_set_l4(ra_rsp, ra);
ra->nd_ra_type = ND_ROUTER_ADVERT;
ra->nd_ra_code = 0;
ra->nd_ra_cksum = htons(0);
ra->nd_ra_curhoplimit = 255;
ra->nd_ra_flags_reserved = 0;
ra->nd_ra_router_lifetime = htons(9000);
ra->nd_ra_reachable = htons(0);
ra->nd_ra_retransmit = htons(0);
packet_set_ipv6(ra_rsp, IPPROTO_ICMPV6, src, dst, 0, 0, 212);
ra->nd_ra_cksum = recalc_csum16(ra->nd_ra_cksum, 0, htons(sizeof(*ra)));
ra->nd_ra_cksum = recalc_csum32(ra->nd_ra_cksum, 0, IPPROTO_ICMPV6);
