Hello David,
sorry for the delay.
At Sun, 11 Oct 2015 12:01:30 -0600,
David Ahern wrote:
>
> On 10/11/15 8:24 AM, Hajime Tazaki wrote:
> >
> > I've faced this issue since the following patch was applied.
> >
> > commit 741a11d9e4103a8e1c590ef1280143fe654e4e33
> > Author: David Ahern <d...@cumulusnetworks.com>
> > Date: Mon Sep 28 10:12:13 2015 -0700
> >
> > net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set
> >
> > I still couldn't spot which part (other than my posted call
> > graph) is broken and am not sure whether the xfrm change
> > affects or not (which I need to check the mip6 code again).
>
> Ok, this is a separate problem from what Steffen is hitting.
agree.
> >
> >> Can you apply this patch, and then run:
> >>
> >> perf record -e fib6:* -a -g
> >> perf script
> >
> > I'm using libos environment right now, so the perf trace
> > can't be used as it is.
>
> ok.
>
> Some path in raw6_sendmsg is setting fl6.flowi6_oif. Can you instrument it?
yes, this sendmsg uses non-zero flowi6_oif.
the conditions are
- sendmsg () with INET6/RAW socket (with IPPROTO_MH)
- ip6_pktinfo.ipi6_addr (fl6.saddr) and ipi6_oif
(fl6.flowi6_oif) are non-NULL.
=> ipi6_addr (fl6.saddr) is not the IP address of oif, but
another interfaces (home address of mip6)
- fib6_lookup() (in ip6_pol_route()) gives ip6_null_entry
if RT6_LOOKUP_F_IFACE isn't set at ip6_route_output, it
can look for a proper dst_entry of default route
if not, it gives EINVAL.
I'm sure that this is not the right fix for this issue, but
the following patch solves my situation.
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index df24cff4a0cb..02e86989b3cb 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1079,6 +1079,12 @@ redo_rt6_select:
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto redo_rt6_select;
+ else if (strict & RT6_LOOKUP_F_IFACE) {
+ /* also consider non-interface route */
+ strict &= ~RT6_LOOKUP_F_IFACE;
+ fn = saved_fn;
+ goto redo_rt6_select;
+ }
else if (strict & RT6_LOOKUP_F_REACHABLE) {
/* also consider unreachable route */
strict &= ~RT6_LOOKUP_F_REACHABLE;
I'm trying to create a minimum reproducible code and spot
the issue but not get it yet. let me know if you find any
good idea.
-- Hajime
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
