On Mon, Aug 24, 2020 at 05:34:09PM +0200, Denis Fondras wrote:
> While working on source selection, I noticed the IPv6 source was not honored
> when set from route(8) with -ifa.
>
> After discussing with florian@, here is a proposed change. It chooses the
> source
> address associated with the route (hence honoring -ifa) instead of the first
> address of the output interface which becomes the source address of last
> resort.
To clarify, this is independent of my recent work in
in6_ifawithscope(), -ifa did not work with the old code, either.
Turns out this is not correct. I seems to always bypass
in6_ifawithscope(), so on a system with slaac where default is on a
link local address this will pick a link local address as the source.
That's not going to work.
>
> Index: netinet6/in6_src.c
> ===================================================================
> RCS file: /cvs/src/sys/netinet6/in6_src.c,v
> retrieving revision 1.81
> diff -u -p -r1.81 in6_src.c
> --- netinet6/in6_src.c 2 Dec 2016 11:16:04 -0000 1.81
> +++ netinet6/in6_src.c 24 Aug 2020 15:14:53 -0000
> @@ -207,13 +207,14 @@ in6_pcbselsrc(struct in6_addr **in6src,
> */
>
> if (ro->ro_rt) {
> - ifp = if_get(ro->ro_rt->rt_ifidx);
> - if (ifp != NULL) {
> - ia6 = in6_ifawithscope(ifp, dst, rtableid);
> - if_put(ifp);
> + ia6 = ifatoia6(ro->ro_rt->rt_ifa);
> + if (ia6 == NULL) {
> + ifp = if_get(ro->ro_rt->rt_ifidx);
> + if (ifp != NULL) {
> + ia6 = in6_ifawithscope(ifp, dst, rtableid);
> + if_put(ifp);
> + }
> }
> - if (ia6 == NULL) /* xxx scope error ?*/
> - ia6 = ifatoia6(ro->ro_rt->rt_ifa);
> }
> if (ia6 == NULL)
> return (EHOSTUNREACH); /* no route */
>
--
I'm not entirely sure you are real.
