Re: [PATCH 2/3] netfilter: Create revision 2 of xt_hashlimit to support higher pps rates

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Wed, Jun 01, 2016 at 08:11:38PM -0400, Vishwanath Pai wrote:
> +static void
> +cfg_copy(struct hashlimit_cfg2 *to, void *from, int revision)
> +{
> +	if (revision == 1) {
> +		struct hashlimit_cfg1 *cfg = (struct hashlimit_cfg1 *)from;
> +
> +		to->mode = cfg->mode;
> +		to->avg = cfg->avg;
> +		to->burst = cfg->burst;
> +		to->size = cfg->size;
> +		to->max = cfg->max;
> +		to->gc_interval = cfg->gc_interval;
> +		to->expire = cfg->expire;
> +		to->srcmask = cfg->srcmask;
> +		to->dstmask = cfg->dstmask;
> +	} else if (revision == 2) {
> +		memcpy(to, from, sizeof(struct hashlimit_cfg2));
> +	} else {
> +		BUG();

BUG here is probably too much, this halts the system. I can see we
only use this somewhere else in this code. Instead, I'd suggest you
propagate an error back to userspace if this ever happen.

I would like to see if this spots any problem with our test
infrastructure under iptables/.

Thanks.