Mailing List Archive

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Hi,

Lukasz Biegaj wrote:
| Is there a way to make OSPF6 work on 2.6.x linux kernels?
|
| Currently I see this in logs:
| 2003/12/24 11:23:13 OSPF6: LSA: originate [AS-External ID=0.0.0.9
Adv=80.55.247.118] seq: 0x80000001 age: 0
| 1072261393.983434
| 2003/12/24 11:23:13 OSPF6: ASBR: start redistributing 2000::/3 as
LS-ID 10: 1072261393.983804
| 2003/12/24 11:23:13 OSPF6: ASBR: schedule redistribution 2000::/3 as
LS-ID 10 after 0 sec
| 2003/12/24 11:23:13 OSPF6: LSA: originate [AS-External ID=0.0.0.10
Adv=80.55.247.118] seq: 0x80000001 age: 0
| 1072261393.983985
| 2003/12/24 11:23:14 OSPF6: Network: Join AllDRouters on ifindex 4
| 2003/12/24 11:23:14 OSPF6: Network: sendmsg (ifindex: 4) failed:
Invalid argument(22)
[...]
| Linux 2.6.0, Debian SID, quagga from apt.
|

we ran into the same problem and found this:

* Linux 2.6 seems to list all multicast / anycast adresses together with
unicast addresses:

[equinox@spaceboyz]:~ # ip a l dc2
9: dc2@NONE: <POINTOPOINT,MULTICAST,NOARP,UP> mtu 1460 qdisc noqueue
~ link/gre 0.0.0.0 peer 217.82.189.49
~ inet 172.22.24.1 peer 172.22.2.2/32 scope global dc2
~ inet6 fe80::ac17:2402/64 scope link
~ valid_lft forever preferred_lft forever
~ inet6 ff02::5/128 scope global
~ valid_lft forever preferred_lft forever
~ inet6 ff02::1/128 scope global
~ valid_lft forever preferred_lft forever
~ inet6 fe80::/128 scope global
~ valid_lft forever preferred_lft forever
(note the 2nd last line)

* ospf6d uses the address list for selecting a linklocal address with
IN6_IS_ADDR_LINKLOCAL
(quagga/ospf6d/ospf_interface.c:192)

~ /* linklocal scope check */
~ if (IN6_IS_ADDR_LINKLOCAL (&c->address->u.prefix6))
~ l = &c->address->u.prefix6;

* IN6_IS_ADDR_LINKLOCAL is defined in /usr/include/netinet/in.h:307 as
follows:

#define IN6_IS_ADDR_LINKLOCAL(a) \
~ ((((__const uint32_t *) (a))[0] & htonl (0xffc00000)) \
~ == htonl (0xfe800000))

* in conjunction with 2.6 reporting all multicast/anycast addresses,
this gets fe80:: (all-routers as far as i remember) into the OSPF6
interface, but the kernel will reject this (of course...):

~ OSPF6: Network: sendmsg (ifindex: 9) failed: Invalid argument(22)


I don't know whose fault it is (how is IN6_IS_ADDR_LINKLOCAL defined to
work? Is it OK for the kernel to include anycast/multicast addresses?)
but this breaks ospf6d. Our fix was to change netinet/in.h because
IN6_IS_ADDR_LINKLOCAL returning !0 only for unicast addresses seemed to
be "the right thing". Patch attached. (categorize that patch as "dirty
works-for-me hack")

David Lamparter


P.S.: glibc people please Cc me, i'm only subscribed to netdev and quagga-*

System environment:
Linux Kernel 2.6.1, x86, non-SMP, preemptible, vanilla
GNU C Library stable release version 2.3.2, by Roland McGrath et al.
quagga 0.96.4 CVS (Fre Jan 16 16:43:35 CET 2004)
gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r3, propolice)

- --
A0C21986 David Lamparter (equinox) <david.lamparter@t-online.de>
2D7F 5CC6 93AD 38DD 6CD5 47A0 A5F0 4657 A0C2 1986
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