Re: [PATCH nf-next 2/2] netfilter: x_tables: fix cgroup's NF_INET_LOCAL_IN sk lookups

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

On Tue, Mar 24, 2015 at 04:30:29PM +0100, Daniel Borkmann wrote:
> diff --git a/net/netfilter/xt_cgroup.c b/net/netfilter/xt_cgroup.c
> index 7198d66..cd2468d 100644
> --- a/net/netfilter/xt_cgroup.c
> +++ b/net/netfilter/xt_cgroup.c
> @@ -16,8 +16,11 @@
>  #include <linux/module.h>
>  #include <linux/netfilter/x_tables.h>
>  #include <linux/netfilter/xt_cgroup.h>
> +
>  #include <net/sock.h>
>  
> +#include "xt_sk_helper.h"
> +
>  MODULE_LICENSE("GPL");
>  MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
>  MODULE_DESCRIPTION("Xtables: process control group matching");
> @@ -34,38 +37,85 @@ static int cgroup_mt_check(const struct xt_mtchk_param *par)
>  	return 0;
>  }
>  
> -static bool
> -cgroup_mt(const struct sk_buff *skb, struct xt_action_param *par)
> +static bool cgroup_mt(const struct sk_buff *skb,
> +		      const struct xt_action_param *par,
> +		      struct sock *(*cgroup_mt_slow)(const struct sk_buff *skb,
> +						     const struct net_device *indev))
>  {
>  	const struct xt_cgroup_info *info = par->matchinfo;
> +	struct sock *sk = skb->sk;
> +	u32 sk_classid;
> +
> +	if (sk) {
> +		sk_classid = sk->sk_classid;
> +	} else {
> +		if (par->in != NULL)
> +			sk = cgroup_mt_slow(skb, par->in);

Is this working with timewait sock?

> +		if (sk == NULL)
> +			return false;
> +
> +		sk_classid = sk->sk_classid;
> +		sock_gen_put(sk);
> +	}
> +
> +	return (info->id == sk_classid) ^ info->invert;
> +}