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Commit 6d4fa852 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

net: sched: add ipset ematch 



Can be used to match packets against netfilter ip sets created via ipset(8).
skb->sk_iif is used as 'incoming interface', skb->dev is 'outgoing interface'.

Since ipset is usually called from netfilter, the ematch
initializes a fake xt_action_param, pulls the ip header into the
linear area and also sets skb->data to the IP header (otherwise
matching Layer 4 set types doesn't work).

Tested-by: default avatarMr Dash Four <mr.dash.four@googlemail.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fa919833

include/linux/pkt_cls.h

+2 −1
Original line number Diff line number Diff line
@@ -453,7 +453,8 @@ enum { 
#define	TCF_EM_TEXT		5

#define	TCF_EM_VLAN		6

#define	TCF_EM_CANID		7

#define	TCF_EM_MAX		7

#define	TCF_EM_IPSET		8

#define	TCF_EM_MAX		8



enum {

	TCF_EM_PROG_TC

net/sched/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -517,6 +517,16 @@ config NET_EMATCH_CANID 
	  To compile this code as a module, choose M here: the

	  module will be called em_canid.



config NET_EMATCH_IPSET

	tristate "IPset"

	depends on NET_EMATCH && IP_SET

	---help---

	  Say Y here if you want to be able to classify packets based on

	  ipset membership.



	  To compile this code as a module, choose M here: the

	  module will be called em_ipset.



config NET_CLS_ACT

	bool "Actions"

	---help---

net/sched/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -56,3 +56,4 @@ obj-$(CONFIG_NET_EMATCH_U32) += em_u32.o 
obj-$(CONFIG_NET_EMATCH_META)	+= em_meta.o

obj-$(CONFIG_NET_EMATCH_TEXT)	+= em_text.o

obj-$(CONFIG_NET_EMATCH_CANID)	+= em_canid.o

obj-$(CONFIG_NET_EMATCH_IPSET)	+= em_ipset.o

net/sched/em_ipset.c

0 → 100644
+135 −0
Original line number Diff line number Diff line 
/*

 * 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/ipv6.h>

#include <net/ip.h>

#include <net/pkt_cls.h>



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

			   struct tcf_ematch *em)

{

	struct xt_set_info *set = data;

	ip_set_id_t index;



	if (data_len != sizeof(*set))

		return -EINVAL;



	index = ip_set_nfnl_get_byindex(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(index);

	return -ENOMEM;

}



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

{

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

	if (set) {

		ip_set_nfnl_put(set->index);

		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;

	int ret, network_offset;



	switch (skb->protocol) {

	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;

	}



	acpar.hooknum = 0;



	opt.family = acpar.family;

	opt.dim = set->dim;

	opt.flags = set->flags;

	opt.cmdflags = 0;

	opt.timeout = ~0u;



	network_offset = skb_network_offset(skb);

	skb_pull(skb, network_offset);



	dev = skb->dev;



	rcu_read_lock();



	if (dev && skb->skb_iif)

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



	acpar.in      = indev ? indev : dev;

	acpar.out     = dev;



	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);