diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-10-04 01:25:26 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-13 05:50:21 +0900 |
| commit | 52fc5048534e9d4127622fa5a269a92f3bb5218b (patch) | |
| tree | 72cf1d0aa74a2acc2ec9b778baa0ef5b7ab2aa7a /include | |
| parent | c1d5777da53b53e02b38845ef9e80ac542f6a08a (diff) | |
ipv4: add a fib_type to fib_info
[ Upstream commit f4ef85bbda96324785097356336bc79cdd37db0a ]
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>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/ip_fib.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 926142ed8d7a..9497be1ad4c0 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; |