/*

 * net/sched/em_ipset.c	ipset ematch

 *

 * Copyright (c) 2012 Florian Westphal <fw@strlen.de>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * version 2 as published by the Free Software Foundation.

 */

#include <linux/gfp.h>

#include <linux/module.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/skbuff.h>

#include <linux/netfilter/xt_set.h>

#include <linux/netfilter/ipset/ip_set_compat.h>

#include <linux/ipv6.h>

#include <net/ip.h>

#include <net/pkt_cls.h>

#ifdef HAVE_TCF_EMATCH_OPS_CHANGE_ARG_NET

static int em_ipset_change(struct net *net, void *data, int data_len,

			   struct tcf_ematch *em)

#else

static int em_ipset_change(struct tcf_proto *tp, void *data, int data_len,

			   struct tcf_ematch *em)

#endif

{

	struct xt_set_info *set = data;

	ip_set_id_t index;

#ifndef HAVE_TCF_EMATCH_OPS_CHANGE_ARG_NET

	struct net *net = dev_net(qdisc_dev(tp->q));

#endif

	if (data_len != sizeof(*set))

		return -EINVAL;

	index = ip_set_nfnl_get_byindex(net, set->index);

	if (index == IPSET_INVALID_ID)

		return -ENOENT;

	em->datalen = sizeof(*set);

	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);

	if (em->data)

		return 0;

	ip_set_nfnl_put(net, index);

	return -ENOMEM;

}

#ifdef HAVE_TCF_EMATCH_STRUCT_NET

static void em_ipset_destroy(struct tcf_ematch *em)

#else

static void em_ipset_destroy(struct tcf_proto *p, struct tcf_ematch *em)

#endif

{

	const struct xt_set_info *set = (const void *) em->data;

	if (set) {

#ifdef HAVE_TCF_EMATCH_STRUCT_NET

		ip_set_nfnl_put(em->net, set->index);

#else

		ip_set_nfnl_put(dev_net(qdisc_dev(p->q)), set->index);

#endif

		kfree((void *) em->data);

	}

}

static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,

			  struct tcf_pkt_info *info)

{

	struct ip_set_adt_opt opt;

	struct xt_action_param acpar;

	const struct xt_set_info *set = (const void *) em->data;

	struct net_device *dev, *indev = NULL;

#ifdef HAVE_STATE_IN_XT_ACTION_PARAM

	struct nf_hook_state state = {

		.net	= em->net,

	};

#endif

	int ret, network_offset;

#ifdef HAVE_STATE_IN_XT_ACTION_PARAM

#define ACPAR_FAMILY(f)		state.pf = f

#else

#define ACPAR_FAMILY(f)		acpar.family = f

#endif

	switch (tc_skb_protocol(skb)) {

	case htons(ETH_P_IP):

		ACPAR_FAMILY(NFPROTO_IPV4);

		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))

			return 0;

		acpar.thoff = ip_hdrlen(skb);

		break;

	case htons(ETH_P_IPV6):

		ACPAR_FAMILY(NFPROTO_IPV6);

		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))

			return 0;

		/* doesn't call ipv6_find_hdr() because ipset doesn't use

		 * thoff, yet

		 */

		acpar.thoff = sizeof(struct ipv6hdr);

		break;

	default:

		return 0;

	}

#ifdef HAVE_STATE_IN_XT_ACTION_PARAM

	opt.family = state.pf;

#else

	acpar.hooknum = 0;

	opt.family = acpar.family;

#endif

	opt.dim = set->dim;

	opt.flags = set->flags;

	opt.cmdflags = 0;

	opt.ext.timeout = ~0u;

	network_offset = skb_network_offset(skb);

	skb_pull(skb, network_offset);

	dev = skb->dev;

	rcu_read_lock();

	if (skb->skb_iif)

#ifdef HAVE_TCF_EMATCH_STRUCT_NET

		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);

#else

		indev = dev_get_by_index_rcu(dev_net(dev), skb->skb_iif);

#endif

#ifdef HAVE_STATE_IN_XT_ACTION_PARAM

	state.in      = indev ? indev : dev;

	state.out     = dev;

	acpar.state   = &stat;;

#else

#ifdef HAVE_NET_IN_XT_ACTION_PARAM

	acpar.net     = em->net;

#endif

	acpar.in      = indev ? indev : dev;

	acpar.out     = dev;

#endif /* HAVE_STATE_IN_XT_ACTION_PARAM */

	ret = ip_set_test(set->index, skb, &acpar, &opt;;

	rcu_read_unlock();

	skb_push(skb, network_offset);

	return ret;

}

static struct tcf_ematch_ops em_ipset_ops = {

	.kind	  = TCF_EM_IPSET,

	.change	  = em_ipset_change,

	.destroy  = em_ipset_destroy,

	.match	  = em_ipset_match,

	.owner	  = THIS_MODULE,

	.link	  = LIST_HEAD_INIT(em_ipset_ops.link)

};

static int __init init_em_ipset(void)

{

	return tcf_em_register(&em_ipset_ops);

}

static void __exit exit_em_ipset(void)

{

	tcf_em_unregister(&em_ipset_ops);

}

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");

MODULE_DESCRIPTION("TC extended match for IP sets");

module_init(init_em_ipset);

module_exit(exit_em_ipset);

MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);