Re: [PATCH net] net: ipv6: Fix ping to link-local addresses.

On 9 August 2016 at 14:20, David Miller [off-list ref] wrote:

From: Lorenzo Colitti <redacted>
Date: Tue, 9 Aug 2016 10:00:25 +0900

quoted

Note that pretty much every sendmsg codepath allows other data to take
precedence over sk_bound_dev_if:

- udpv6_sendmsg: if sin6_scope_id specified on a scoped address
- rawv6_sendmsg: if sin6_scope_id specified on a scoped address
- l2tp_ip6_sendmsg: if sin6_scope_id specified on a scoped address
- ip_cmsg_send: if IP_PKTINFO or IPV6_PKTINFO specified

What should I do about those? -EINVAL? Ignore the conflicting data? Leave as is?

That's a good point, I guess this needs some more thought.

I could see a point of view that says when bound_if is in play sending
to destinations on/via other interfaces--by any mechanism--should
effectively get ENETUNREACH (or something).

That does seem like I would involve changing some existing behavior, though.