* IPV6_PKTINFO seems not to be honored correctly by RAW-sockets
@ 2012-10-30 8:58 Steven Barth
2012-10-30 10:42 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Steven Barth @ 2012-10-30 8:58 UTC (permalink / raw)
To: netdev; +Cc: Steven Barth
Hi,
I recently noticed that there might be an unexpected behavior in the
handling of IPV6_PKTINFO for RAW-sockets. It seems that the given
destination interface is ignored.
I just reproduced this on 3.7.0-rc3 vanilla but some quick tests with
2.6.32 and 3.5 distro-kernels on different machines showed the same.
I've noticed this first in my own software but I could also reproduce it
easily with standard tools like ping6 from iputils:
Have 2 network interfaces with (global) IPv6-addresses assigned (e.g.
eth0 with fd00::1/64 and eth1 with fd01::1/64) and do a ping6 -I eth1
fd00::1 (ping6 from iputils uses IPV6_PKTINFO internally).
For me the result was that even though I set the interface to eth1 the
ECHO was still send to eth0.
Also (although probably unrelated) forwarding for IPv6 was disabled.
If I try something similar with IPv4 and ping -I ... the ECHO doesn't go
out on eth0 but - as expected - on eth1.
However if I use traceroute(6) with -I (ICMP-traceroute) and the -i
option to determine the interface, packages seem to be sent through the
expected interface. Internally it seems that traceroute(6) uses
SO_BINDTODEVICE instead of IP(V6)_PKTINFO which seems to work.
So it seems there might be something wrong with IPV6_PKTINFO or is this
expected behavior?
Thanks and Regards,
Steven
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: IPV6_PKTINFO seems not to be honored correctly by RAW-sockets
2012-10-30 8:58 IPV6_PKTINFO seems not to be honored correctly by RAW-sockets Steven Barth
@ 2012-10-30 10:42 ` Eric Dumazet
2012-10-30 16:52 ` Steven Barth
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2012-10-30 10:42 UTC (permalink / raw)
To: Steven Barth; +Cc: netdev
From: Eric Dumazet <edumazet@google.com>
On Tue, 2012-10-30 at 09:58 +0100, Steven Barth wrote:
> Hi,
>
> I recently noticed that there might be an unexpected behavior in the
> handling of IPV6_PKTINFO for RAW-sockets. It seems that the given
> destination interface is ignored.
>
> I just reproduced this on 3.7.0-rc3 vanilla but some quick tests with
> 2.6.32 and 3.5 distro-kernels on different machines showed the same.
>
> I've noticed this first in my own software but I could also reproduce it
> easily with standard tools like ping6 from iputils:
>
> Have 2 network interfaces with (global) IPv6-addresses assigned (e.g.
> eth0 with fd00::1/64 and eth1 with fd01::1/64) and do a ping6 -I eth1
> fd00::1 (ping6 from iputils uses IPV6_PKTINFO internally).
>
> For me the result was that even though I set the interface to eth1 the
> ECHO was still send to eth0.
>
> Also (although probably unrelated) forwarding for IPv6 was disabled.
>
> If I try something similar with IPv4 and ping -I ... the ECHO doesn't go
> out on eth0 but - as expected - on eth1.
>
> However if I use traceroute(6) with -I (ICMP-traceroute) and the -i
> option to determine the interface, packages seem to be sent through the
> expected interface. Internally it seems that traceroute(6) uses
> SO_BINDTODEVICE instead of IP(V6)_PKTINFO which seems to work.
>
> So it seems there might be something wrong with IPV6_PKTINFO or is this
> expected behavior?
>
I believe its not expected behavior.
Is the following patch fixing it ?
Thanks
[PATCH] ipv6: raw: honor IPV6_PKTINFO
Let ping6 -I interface works correctly.
If socket was not bound to a given interface, check if IPV6_PKTINFO was
issued on this socket.
Reported-by: Steven Barth <steven@midlink.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index d8e95c7..363ee65 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -814,8 +814,8 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
fl6.flowlabel = np->flow_label;
}
- if (fl6.flowi6_oif == 0)
- fl6.flowi6_oif = sk->sk_bound_dev_if;
+ if (!fl6.flowi6_oif)
+ fl6.flowi6_oif = sk->sk_bound_dev_if ?: np->sticky_pktinfo.ipi6_ifindex;
if (msg->msg_controllen) {
opt = &opt_space;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: IPV6_PKTINFO seems not to be honored correctly by RAW-sockets
2012-10-30 10:42 ` Eric Dumazet
@ 2012-10-30 16:52 ` Steven Barth
0 siblings, 0 replies; 3+ messages in thread
From: Steven Barth @ 2012-10-30 16:52 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev
Thanks for your quick reply.
I just saw that there is also a IPV6_PKTINFO setsockopt-option which was
probably what your patch affects.
However what I actually meant was the IPV6_PKTINFO control message for
sendmsg. Sorry for being ambiguous here. I tried to trace the bug down a
bit further with my unfortunately very limited kernel debugging skills.
It seems that the destined interface is correctly set in fl6->flowi6_oif
also still when it reaches ip6_push_pending_frames in ip6_output.c so I
guess it must be lost some time later but I couldn't find out exactly
where yet. I'll try to find more information later if I can find some
free time.
Regards,
Steven
On 30.10.2012 11:42, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> On Tue, 2012-10-30 at 09:58 +0100, Steven Barth wrote:
>> Hi,
>>
>> I recently noticed that there might be an unexpected behavior in the
>> handling of IPV6_PKTINFO for RAW-sockets. It seems that the given
>> destination interface is ignored.
>>
>> I just reproduced this on 3.7.0-rc3 vanilla but some quick tests with
>> 2.6.32 and 3.5 distro-kernels on different machines showed the same.
>>
>> I've noticed this first in my own software but I could also reproduce it
>> easily with standard tools like ping6 from iputils:
>>
>> Have 2 network interfaces with (global) IPv6-addresses assigned (e.g.
>> eth0 with fd00::1/64 and eth1 with fd01::1/64) and do a ping6 -I eth1
>> fd00::1 (ping6 from iputils uses IPV6_PKTINFO internally).
>>
>> For me the result was that even though I set the interface to eth1 the
>> ECHO was still send to eth0.
>>
>> Also (although probably unrelated) forwarding for IPv6 was disabled.
>>
>> If I try something similar with IPv4 and ping -I ... the ECHO doesn't go
>> out on eth0 but - as expected - on eth1.
>>
>> However if I use traceroute(6) with -I (ICMP-traceroute) and the -i
>> option to determine the interface, packages seem to be sent through the
>> expected interface. Internally it seems that traceroute(6) uses
>> SO_BINDTODEVICE instead of IP(V6)_PKTINFO which seems to work.
>>
>> So it seems there might be something wrong with IPV6_PKTINFO or is this
>> expected behavior?
>>
>
> I believe its not expected behavior.
>
> Is the following patch fixing it ?
>
> Thanks
>
> [PATCH] ipv6: raw: honor IPV6_PKTINFO
>
> Let ping6 -I interface works correctly.
>
> If socket was not bound to a given interface, check if IPV6_PKTINFO was
> issued on this socket.
>
> Reported-by: Steven Barth <steven@midlink.org>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
> diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
> index d8e95c7..363ee65 100644
> --- a/net/ipv6/raw.c
> +++ b/net/ipv6/raw.c
> @@ -814,8 +814,8 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
> fl6.flowlabel = np->flow_label;
> }
>
> - if (fl6.flowi6_oif == 0)
> - fl6.flowi6_oif = sk->sk_bound_dev_if;
> + if (!fl6.flowi6_oif)
> + fl6.flowi6_oif = sk->sk_bound_dev_if ?: np->sticky_pktinfo.ipi6_ifindex;
>
> if (msg->msg_controllen) {
> opt = &opt_space;
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-10-30 16:52 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2012-10-30 8:58 IPV6_PKTINFO seems not to be honored correctly by RAW-sockets Steven Barth
2012-10-30 10:42 ` Eric Dumazet
2012-10-30 16:52 ` Steven Barth
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