* [PATCH] ipv4: Use netinet->inet_opt in inet_csk_route_child_sock()
@ 2012-08-17 21:35 Christoph Paasch
2012-08-20 9:51 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Paasch @ 2012-08-17 21:35 UTC (permalink / raw)
To: David Miller; +Cc: netdev
Since 0e734419923bd ("ipv4: Use inet_csk_route_child_sock() in DCCP and
TCP."), inet_csk_route_child_sock() is called instead of
inet_csk_route_req().
However, after creating the child-sock in tcp/dccp_v4_syn_recv_sock(),
ireq->opt is set to NULL, before calling inet_csk_route_child_sock().
Thus, inside inet_csk_route_child_sock() opt is always NULL and the
SRR-options are not respected anymore.
Packets sent by the server won't have the correct destination-IP.
This patch fixes it by accessing newinet->inet_opt instead of ireq->opt
inside inet_csk_route_child_sock().
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
---
net/ipv4/inet_connection_sock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index db0cf17..f16bdc4 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -404,7 +404,7 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
{
const struct inet_request_sock *ireq = inet_rsk(req);
struct inet_sock *newinet = inet_sk(newsk);
- struct ip_options_rcu *opt = ireq->opt;
+ struct ip_options_rcu *opt = rcu_dereference(newinet->inet_opt);
struct net *net = sock_net(sk);
struct flowi4 *fl4;
struct rtable *rt;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ipv4: Use netinet->inet_opt in inet_csk_route_child_sock()
2012-08-17 21:35 [PATCH] ipv4: Use netinet->inet_opt in inet_csk_route_child_sock() Christoph Paasch
@ 2012-08-20 9:51 ` David Miller
2012-08-20 12:11 ` Christoph Paasch
0 siblings, 1 reply; 3+ messages in thread
From: David Miller @ 2012-08-20 9:51 UTC (permalink / raw)
To: christoph.paasch; +Cc: netdev
From: Christoph Paasch <christoph.paasch@uclouvain.be>
Date: Fri, 17 Aug 2012 23:35:12 +0200
> @@ -404,7 +404,7 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
> {
> const struct inet_request_sock *ireq = inet_rsk(req);
> struct inet_sock *newinet = inet_sk(newsk);
> - struct ip_options_rcu *opt = ireq->opt;
> + struct ip_options_rcu *opt = rcu_dereference(newinet->inet_opt);
> struct net *net = sock_net(sk);
We're not inside of a rcu_read_lock() protected section, so this access
is not legitimate. If you enabled RCU lock debugging, you would have
triggered a warning in the kernel log.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ipv4: Use netinet->inet_opt in inet_csk_route_child_sock()
2012-08-20 9:51 ` David Miller
@ 2012-08-20 12:11 ` Christoph Paasch
0 siblings, 0 replies; 3+ messages in thread
From: Christoph Paasch @ 2012-08-20 12:11 UTC (permalink / raw)
To: David Miller; +Cc: netdev
On Monday 20 August 2012 02:51:47 David Miller wrote:
> From: Christoph Paasch <christoph.paasch@uclouvain.be>
> Date: Fri, 17 Aug 2012 23:35:12 +0200
>
> > @@ -404,7 +404,7 @@ struct dst_entry *inet_csk_route_child_sock(struct
> > sock *sk,>
> > {
> > const struct inet_request_sock *ireq = inet_rsk(req);
> > struct inet_sock *newinet = inet_sk(newsk);
> >
> > - struct ip_options_rcu *opt = ireq->opt;
> > + struct ip_options_rcu *opt = rcu_dereference(newinet->inet_opt);
> >
> > struct net *net = sock_net(sk);
>
> We're not inside of a rcu_read_lock() protected section, so this access
> is not legitimate. If you enabled RCU lock debugging, you would have
> triggered a warning in the kernel log.
Oh, sorry... I will resubmit a v2.
Although, I enabled CONFIG_PROVE_RCU (and all other RCU-related debug I could
find) and no warning was triggered.
By the way, in dccp_v4_request_recv_sock() is the code:
newinet->inet_opt = ireq->opt;
Shouldn't this rather be an rcu_assign_pointer() ?
And in cipso_v4_sock_delattr() I believe we should also rather access 'opt'
instead of doing cipso_v4_delopt(&sk_inet->inet_opt) ?
Christoph
--
IP Networking Lab --- http://inl.info.ucl.ac.be
MultiPath TCP in the Linux Kernel --- http://mptcp.info.ucl.ac.be
Université Catholique de Louvain
--
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-08-17 21:35 [PATCH] ipv4: Use netinet->inet_opt in inet_csk_route_child_sock() Christoph Paasch
2012-08-20 9:51 ` David Miller
2012-08-20 12:11 ` Christoph Paasch
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