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

From: "Michael S. Tsirkin" <[email-masked]>
Date: Sun, 25 Apr 2010 19:35:43 +0300

On Sun, Apr 25, 2010 at 06:21:00PM +0200, Eric Dumazet wrote:
> 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 ([email-masked]) 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 <[email-masked]>
> Signed-off-by: Eric Dumazet <[email-masked]>
> ---
> 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;
>  		}
> 

works for me
Tested-by: Michael S. Tsirkin <[email-masked]>