Re: PROBLEM: Linux kernel 2.6.31 IPv4 TCP fails to open huge amount of outgoing connections (unable to bind ... )

[Eric Dumazet <eric.dumazet@gmail.com>]

Le dimanche 25 avril 2010 à 19:56 +0400, Evgeniy Polyakov a écrit :
> On Sun, Apr 25, 2010 at 05:26:42PM +0300, Michael S. Tsirkin (mst@redhat.com) wrote:
> 
> > > diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
> > > index 0c5e3c3..fb6959c 100644
> > > --- a/net/ipv6/inet6_connection_sock.c
> > > +++ b/net/ipv6/inet6_connection_sock.c
> > > @@ -42,11 +42,16 @@ int inet6_csk_bind_conflict(const struct sock *sk,
> > >  		if (sk != sk2 &&
> > >  		    (!sk->sk_bound_dev_if ||
> > >  		     !sk2->sk_bound_dev_if ||
> > > -		     sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
> > > -		    (!sk->sk_reuse || !sk2->sk_reuse ||
> > > -		     sk2->sk_state == TCP_LISTEN) &&
> > > -		     ipv6_rcv_saddr_equal(sk, sk2))
> > > -			break;
> > > +		     sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
> > > +			if ((!sk->sk_reuse || !sk2->sk_reuse ||
> > > +			     sk2->sk_state == TCP_LISTEN) &&
> > > +			     ipv6_rcv_saddr_equal(sk, sk2))
> > > +				break;
> > > +			else if (sk->sk_reuse && sk2->sk_reuse &&
> > > +				!ipv6_addr_any(inet6_rcv_saddr(sk2)) &&
> 
> I suppose above line is guilty when inet6_rcv_saddr() returns NULL?
> 

Sorry, I cant test this at this moment (I am travelling)

Evgeniy, David could you double check ?

Michael, could you test this patch ?

Thanks !

[PATCH] ipv6: Fix inet6_csk_bind_conflict()

Commit fda48a0d7a84 (tcp: bind() fix when many ports are bound)
introduced a bug on IPV6 part.
We should not call ipv6_addr_any(inet6_rcv_saddr(sk2)) but
ipv6_addr_any(inet6_rcv_saddr(sk)) because sk2 can be IPV4, while sk is
IPV6.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index b4b7d40..3a4d92b 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -48,7 +48,7 @@ int inet6_csk_bind_conflict(const struct sock *sk,
 			     ipv6_rcv_saddr_equal(sk, sk2))
 				break;
 			else if (sk->sk_reuse && sk2->sk_reuse &&
-				!ipv6_addr_any(inet6_rcv_saddr(sk2)) &&
+				!ipv6_addr_any(inet6_rcv_saddr(sk)) &&
 				ipv6_rcv_saddr_equal(sk, sk2))
 				break;
 		}