Re: [PATCH] net/ipv4/tcp.c little cleanup

[Eduard Roccatello <lilo@roccatello.it>]

On Friday 23 January 2004 00:48, Willy Tarreau wrote:
> Hi !
>
> On Thu, Jan 22, 2004 at 10:53:37PM +0100, Eduard Roccatello wrote:
> > Hello,
> > i've done a little cleanup to net/ipv4/tcp.c
> >
> > I hope it is ok :-)
>
> I haven't looked at sysctl_max_syn_backlog type, but if it's unsigned,
> there's a risk of infinite loop for values above 2^31 on 32 bits
> machines, or 2^63 on 64 bits machine.
sysctl_max_syn_backlog is an int and max_qlen_log is a u8 (uint8_t).
i think there is no problem with them.
sysctl_max_syn_backlog max value is 1024 so max_qlen_log is just 9.

is it ok for you?

> > --- net/ipv4/tcp.c.orig	2004-01-22 22:49:38.000000000 +0100
> > +++ net/ipv4/tcp.c	2004-01-22 22:42:38.000000000 +0100
> > @@ -549,9 +549,9 @@ int tcp_listen_start(struct sock *sk)
> >  	 	return -ENOMEM;
> >
> > 	memset(lopt, 0, sizeof(struct tcp_listen_opt));
> > -	for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++)
> > -		if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog)
> > -			break;
> > +	lopt->max_qlen_log = 6;
> > +	while (sysctl_max_syn_backlog > (1 << lopt->max_qlen_log))
> > +		lopt->max_qlen_log++;
> >  	get_random_bytes(&lopt->hash_rnd, 4);
> >
> >  	write_lock_bh(&tp->syn_wait_lock);