On Tue, Apr 17, 2012 at 11:37:52AM +0100, Howden Nick wrote:
> Hi,
>
> I tried to post this to the mailing list but to no avail.
Don't know why it wasn't delivered.
> I wonder if you can shed some light on the problem we are having with
> devices not being preserved when Bird updates the kernel routing tables.
> >birdc show table BIRD
> ...
> 11.6.9.0/24 via 11.6.1.200 on TAP_One [MYOSPF 16:04] * I (100/10436)
> ...
> The BIRD table contains the correct network device TAP_One
> >ip route ls table NEW
> ...
> 11.6.9.0/24 via 11.6.1.200 dev TAP_Two proto bird
> ...
> But, when we inspect the kernel table the network device information has
> been lost.
Generally, BIRD assumed that IP address is the whole key for gw and
iface is derivable from it. With IPv6 and link-local addresses that had
to changed, but it probably remained in some parts where it is not
relevant to that. I personally never tested this variant.
> Tap_One and Tap_Two both have IP addresses in the range 11.6.1.0/24 and I
> am relying on the routing tables being correct in order to identify the
> correct interface to use for the outbound traffic. The behaviour we are
> seeing is the behaviour we expect if routes are added as:
> ip route add 11.6.9.0/24 via 11.6.1.200 table NEW
> instead of
> ip route add 11.6.9.0/24 via 11.6.1.200 dev TAP_One table NEW
You are right, for some unknown reason device is not used when route is
propagated to the kernel. You could try attached patch.
> My understanding was that the "device routes" option would allow the
> device part of the routes to be preserved but there is clearly a flaw in
> my knowledge.
No, that 'device routes' is something completely different - whether
device routes (routes without via/gw) are propagated.
> Is it actually possible to preserve the device information present in the
> BIRD routing tables when they are exported to kernel tables?
Try attached patch.
--
Elen sila lumenn' omentielvo
Ondrej 'SanTiago' Zajicek (email: [email protected])
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
diff --git a/sysdep/linux/netlink/netlink.c b/sysdep/linux/netlink/netlink.c
index c8eed0f..968a872 100644
--- a/sysdep/linux/netlink/netlink.c
+++ b/sysdep/linux/netlink/netlink.c
@@ -588,7 +588,7 @@ krt_capable(rte *e)
switch (a->dest)
{
case RTD_ROUTER:
- if (ipa_has_link_scope(a->gw) && (a->iface == NULL))
+ if (a->iface == NULL)
return 0;
case RTD_DEVICE:
case RTD_BLACKHOLE:
@@ -660,8 +660,7 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
/* a->iface != NULL checked in krt_capable() */
- if (ipa_has_link_scope(a->gw))
- nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
break;
case RTD_DEVICE:
