Denis Fondras(de...@openbsd.org) on 2018.05.24 17:57:19 +0200:
> On Thu, May 24, 2018 at 07:04:04AM -0400, David Higgs wrote:
> > But shouldn???t the answer be the same, since I have a valid default route?
> >
>
> It should but that's not how route(8) works for now :)
>
> Barely tested diff, assumes that no netmask means /128 (similar to IPv4
> handling
> where no netmask means /32)
But it doesn't:
[benoit@blap:~]$ doas route add 192.168.5 10.8.0.137
[benoit@blap:~]$ doas route -n get 192.168.5.33
route to: 192.168.5.33
destination: 192.168.5.0
mask: 255.255.255.0
gateway: 10.8.0.137
---> 192.168.5 is interpreted as /24
[benoit@blap:~]$ doas route delete 192.168.5 10.8.0.137
delete net 192.168.5: gateway 10.8.0.137
---> 192.168.5.0/24 is deleted
Indeed, if i do
[benoit@blap:~]$ doas route add 192.168.5.66 10.8.0.137
add host 192.168.5.66: gateway 10.8.0.137
i get a /32 route
[benoit@blap:~]$ doas route -n get 192.168.5.66
route to: 192.168.5.66
destination: 192.168.5.66
mask: 255.255.255.255
gateway: 10.8.0.137
but thats equivalent to doing
[benoit@blap:~]$ route add 2607:f8b0:4004:805::2004 ::
Now. for ipv6 the spec says what 2607:f8b0:4004:805::
means, whereas for ipv4 its just historical accident that
192.168.5 is interpreded in some way.
So i think the answer to the OP is: always use a netmask, except when you
specify full host address.
/Benno
> Index: route.c
> ===================================================================
> RCS file: /cvs/src/sbin/route/route.c,v
> retrieving revision 1.214
> diff -u -p -r1.214 route.c
> --- route.c 1 May 2018 18:14:10 -0000 1.214
> +++ route.c 24 May 2018 15:54:37 -0000
> @@ -800,13 +800,8 @@ inet6_makenetandmask(struct sockaddr_in6
> if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) &&
> sin6->sin6_scope_id == 0) {
> plen = "0";
> - } else if ((sin6->sin6_addr.s6_addr[0] & 0xe0) == 0x20) {
> - /* aggregatable global unicast - RFC2374 */
> - memset(&in6, 0, sizeof(in6));
> - if (!memcmp(&sin6->sin6_addr.s6_addr[8],
> - &in6.s6_addr[8], 8))
> - plen = "64";
> - }
> + } else
> + plen = "128";
> }
>
> if (!plen || strcmp(plen, "128") == 0)
>
--
