| Message ID | 1349349926.16011.48.camel@edumazet-glaptop |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 10/04/12 12:25, Eric Dumazet wrote: > On Tue, 2012-10-02 at 17:48 +0200, Eric Dumazet wrote: >> From: Eric Dumazet <edumazet@google.com> >> >> On Tue, 2012-10-02 at 17:35 +0200, Eric Dumazet wrote: >>> On Mon, 2012-10-01 at 22:04 +0200, Eric Dumazet wrote: >>>> On Mon, 2012-10-01 at 16:01 -0400, David Miller wrote: >>> >>>>> If you can find a way to more reliably trigger the case, that would >>>>> help us immensely. >>>> >>>> I am building a KMEMCHECK kernel, as a last try before my night ;) >>> >>> This was a total disaster. KMEMCHECK dies horribly on my machine >>> >>> David, shouldnt we use a nh_rth_forward instead of a nh_rth_input in >>> __mkroute_input() ? >>> >>> (And change rt_cache_route() as well ?) >>> >>> I am testing a patch right now. >> > > OK so I implemented David idea and it seems to work. > > Testers are needed, thanks ! ;) > I've tested 3.6.0 with this patch applied and networking in a WinXP KVM client is now working fine. The patch applies cleanly to 3.6.0, so I assume the patch will be forwarded to stable in due course. Tested-by: Chris Clayton <chris2553@googlemail.com> > [PATCH] ipv4: add a fib_type to fib_info > > commit d2d68ba9fe8 (ipv4: Cache input routes in fib_info nexthops.) > introduced a regression for forwarding. > > This was hard to reproduce but the symptom was that packets were > delivered to local host instead of being forwarded. > > David suggested to add fib_type to fib_info so that we dont > inadvertently share same fib_info for different purposes. > > With help from Julian Anastasov who provided very helpful > hints, reproduced here : > > <quote> > Can it be a problem related to fib_info reuse > from different routes. For example, when local IP address > is created for subnet we have: > > broadcast 192.168.0.255 dev DEV proto kernel scope link src > 192.168.0.1 > 192.168.0.0/24 dev DEV proto kernel scope link src 192.168.0.1 > local 192.168.0.1 dev DEV proto kernel scope host src 192.168.0.1 > > The "dev DEV proto kernel scope link src 192.168.0.1" is > a reused fib_info structure where we put cached routes. > The result can be same fib_info for 192.168.0.255 and > 192.168.0.0/24. RTN_BROADCAST is cached only for input > routes. Incoming broadcast to 192.168.0.255 can be cached > and can cause problems for traffic forwarded to 192.168.0.0/24. > So, this patch should solve the problem because it > separates the broadcast from unicast traffic. > > And the ip_route_input_slow caching will work for > local and broadcast input routes (above routes 1 and 3) just > because they differ in scope and use different fib_info. > > </quote> > > Many thanks to Chris Clayton for his patience and help. > > Reported-by: Chris Clayton <chris2553@googlemail.com> > Bisected-by: Chris Clayton <chris2553@googlemail.com> > Reported-by: Dave Jones <davej@redhat.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Julian Anastasov <ja@ssi.bg> > --- > include/net/ip_fib.h | 1 + > net/ipv4/fib_semantics.c | 2 ++ > 2 files changed, 3 insertions(+) > > diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h > index 926142e..9497be1 100644 > --- a/include/net/ip_fib.h > +++ b/include/net/ip_fib.h > @@ -102,6 +102,7 @@ struct fib_info { > unsigned char fib_dead; > unsigned char fib_protocol; > unsigned char fib_scope; > + unsigned char fib_type; > __be32 fib_prefsrc; > u32 fib_priority; > u32 *fib_metrics; > diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c > index 3509065..2677530 100644 > --- a/net/ipv4/fib_semantics.c > +++ b/net/ipv4/fib_semantics.c > @@ -314,6 +314,7 @@ static struct fib_info *fib_find_info(const struct fib_info *nfi) > nfi->fib_scope == fi->fib_scope && > nfi->fib_prefsrc == fi->fib_prefsrc && > nfi->fib_priority == fi->fib_priority && > + nfi->fib_type == fi->fib_type && > memcmp(nfi->fib_metrics, fi->fib_metrics, > sizeof(u32) * RTAX_MAX) == 0 && > ((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_F_DEAD) == 0 && > @@ -833,6 +834,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg) > fi->fib_flags = cfg->fc_flags; > fi->fib_priority = cfg->fc_priority; > fi->fib_prefsrc = cfg->fc_prefsrc; > + fi->fib_type = cfg->fc_type; > > fi->fib_nhs = nhs; > change_nexthops(fi) { > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2012-10-04 at 14:08 +0100, Chris Clayton wrote: > I've tested 3.6.0 with this patch applied and networking in a WinXP KVM > client is now working fine. The patch applies cleanly to 3.6.0, so I > assume the patch will be forwarded to stable in due course. > > Tested-by: Chris Clayton <chris2553@googlemail.com> Thanks for testing. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Thu, 04 Oct 2012 15:32:08 +0200 > On Thu, 2012-10-04 at 14:08 +0100, Chris Clayton wrote: > >> I've tested 3.6.0 with this patch applied and networking in a WinXP KVM >> client is now working fine. The patch applies cleanly to 3.6.0, so I >> assume the patch will be forwarded to stable in due course. >> >> Tested-by: Chris Clayton <chris2553@googlemail.com> > > Thanks for testing. Applied and queued up for -stable, thanks everyone. Note that this change means we can completely remove the type fields from fib_alias and fib_result when net-next opens up, as the value can be fetched from the fib_info directly now. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 926142e..9497be1 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -102,6 +102,7 @@ struct fib_info { unsigned char fib_dead; unsigned char fib_protocol; unsigned char fib_scope; + unsigned char fib_type; __be32 fib_prefsrc; u32 fib_priority; u32 *fib_metrics; diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 3509065..2677530 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -314,6 +314,7 @@ static struct fib_info *fib_find_info(const struct fib_info *nfi) nfi->fib_scope == fi->fib_scope && nfi->fib_prefsrc == fi->fib_prefsrc && nfi->fib_priority == fi->fib_priority && + nfi->fib_type == fi->fib_type && memcmp(nfi->fib_metrics, fi->fib_metrics, sizeof(u32) * RTAX_MAX) == 0 && ((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_F_DEAD) == 0 && @@ -833,6 +834,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg) fi->fib_flags = cfg->fc_flags; fi->fib_priority = cfg->fc_priority; fi->fib_prefsrc = cfg->fc_prefsrc; + fi->fib_type = cfg->fc_type; fi->fib_nhs = nhs; change_nexthops(fi) {