Subject: Re: [patch v2.3 1/4] netfilter: xt_ipvs (netfilter matcher for IPVS)

From: Patrick McHardy <[email-masked]>
Date: Tue, 06 Jul 2010 13:32:48 +0200

Simon Horman wrote:
> From:	Hannes Eder <[email-masked]>
>
> This implements the kernel-space side of the netfilter matcher xt_ipvs.
>   
> @@ -0,0 +1,25 @@
> +#ifndef _XT_IPVS_H
> +#define _XT_IPVS_H
> +
> +#define XT_IPVS_IPVS_PROPERTY	(1 << 0) /* all other options imply this one */
> +#define XT_IPVS_PROTO		(1 << 1)
> +#define XT_IPVS_VADDR		(1 << 2)
> +#define XT_IPVS_VPORT		(1 << 3)
> +#define XT_IPVS_DIR		(1 << 4)
> +#define XT_IPVS_METHOD		(1 << 5)
> +#define XT_IPVS_VPORTCTL	(1 << 6)
> +#define XT_IPVS_MASK		((1 << 7) - 1)
> +#define XT_IPVS_ONCE_MASK	(XT_IPVS_MASK & ~XT_IPVS_IPVS_PROPERTY)
> +
> +struct xt_ipvs_mtinfo {
> +	union nf_inet_addr	vaddr, vmask;
> +	__be16			vport;
> +	__u16			l4proto;
> +	__u16			fwd_method;
>   
It seems you could use __u8 for both l4proto and fwd_method
and reduce the match size by 2 bytes.

> +	__be16			vportctl;
> +
> +	__u8			invert;
> +	__u8			bitmask;
> +};
> +static bool
> +ipvs_mt(const struct sk_buff *skb, struct xt_action_param *par)
> +...
>   
> +	if (data->bitmask & XT_IPVS_DIR) {
> +		enum ip_conntrack_info ctinfo;
> +		struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
> +
> +		if (ct == NULL || ct == &nf_conntrack_untracked) {
>   
We're using per-cpu structures for nf_conntrack_untracked in the
current net-next/nf-next tree, so this doesn't work anymore. You
need to use nf_ct_is_untracked() instead.

> +			match = false;
> +			goto out_put_cp;
> +		}