Am 01/23/17 um 00:34 schrieb Jeremie Courreges-Anglas: > Stuart Henderson <s...@spacehopper.org> writes: > >> >> Here is the upstream code with more context. >> >> 789 /* >> 790 * Set the target address we're sending to. >> 791 * Enforce the scope ID for bogus BSDs. >> 792 */ >> 793 memcpy(&dst, to, sizeof(dst)); >> 794 m.msg_name = &dst; >> 795 m.msg_namelen = sizeof(dst); >> 796 ifindex = if_nametoindex(interface->name); >> 797 if (no_global_v6_socket) >> 798 dst.sin6_scope_id = ifindex; >> >> So, setting the scope ID is exactly what they are already trying to do. >> I don't really want to spend much time understanding code which they >> have marked as "XXX: this is gross. we need to go back and overhaul the >> API for socket handling". But it looks like they'd be expecting >> no_global_v6_socket to be set on a BSD which needs the scope id. > > Whether no_global_v6_socket is true doesn't seem to depend on the OS: it > appears true when running dhclient, false when running dhcpd/dhcrelay; > see if_register_linklocal6(). This looks more like a lack of testing, > as it appears safe to set sin6_scope_id everywhere. > >> Better if someone who already knows the code looks at it - can you >> bring this up on dhcp-users or somewhere similar? > > I don't volunteer to move this to dhcp-users... yet. Maybe the actual > fix is in our base system. It *looks like* our kernel has indeed a bug, > it should use the ifindex in the cmsg. >
Ok, i already prepared a mail i was going to send later today, but if the bug is in our base system, it won't do any good. Maybe someone with knowledge of the network stack can have a look? I would help in testing patches.
