1/*
  2 * net/sched/em_ipset.c	ipset ematch
  3 *
  4 * Copyright (c) 2012 Florian Westphal <fw@strlen.de>
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License
  8 * version 2 as published by the Free Software Foundation.
  9 */
 10
 11#include <linux/gfp.h>
 12#include <linux/module.h>
 13#include <linux/types.h>
 14#include <linux/kernel.h>
 15#include <linux/string.h>
 16#include <linux/skbuff.h>
 17#include <linux/netfilter/xt_set.h>
 18#include <linux/ipv6.h>
 19#include <net/ip.h>
 20#include <net/pkt_cls.h>
 21
 22static int em_ipset_change(struct tcf_proto *tp, void *data, int data_len,
 23			   struct tcf_ematch *em)
 24{
 25	struct xt_set_info *set = data;
 26	ip_set_id_t index;
 27	struct net *net = dev_net(qdisc_dev(tp->q));
 28
 29	if (data_len != sizeof(*set))
 30		return -EINVAL;
 31
 32	index = ip_set_nfnl_get_byindex(net, set->index);
 33	if (index == IPSET_INVALID_ID)
 34		return -ENOENT;
 35
 36	em->datalen = sizeof(*set);
 37	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
 38	if (em->data)
 39		return 0;
 40
 41	ip_set_nfnl_put(net, index);
 42	return -ENOMEM;
 43}
 44
 45static void em_ipset_destroy(struct tcf_proto *p, struct tcf_ematch *em)
 46{
 47	const struct xt_set_info *set = (const void *) em->data;
 48	if (set) {
 49		ip_set_nfnl_put(dev_net(qdisc_dev(p->q)), set->index);
 50		kfree((void *) em->data);
 51	}
 52}
 53
 54static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
 55			  struct tcf_pkt_info *info)
 56{
 57	struct ip_set_adt_opt opt;
 58	struct xt_action_param acpar;
 59	const struct xt_set_info *set = (const void *) em->data;
 60	struct net_device *dev, *indev = NULL;
 61	int ret, network_offset;
 62
 63	switch (skb->protocol) {
 64	case htons(ETH_P_IP):
 65		acpar.family = NFPROTO_IPV4;
 66		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
 67			return 0;
 68		acpar.thoff = ip_hdrlen(skb);
 69		break;
 70	case htons(ETH_P_IPV6):
 71		acpar.family = NFPROTO_IPV6;
 72		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
 73			return 0;
 74		/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
 75		acpar.thoff = sizeof(struct ipv6hdr);
 76		break;
 77	default:
 78		return 0;
 79	}
 80
 81	acpar.hooknum = 0;
 82
 83	opt.family = acpar.family;
 84	opt.dim = set->dim;
 85	opt.flags = set->flags;
 86	opt.cmdflags = 0;
 87	opt.ext.timeout = ~0u;
 88
 89	network_offset = skb_network_offset(skb);
 90	skb_pull(skb, network_offset);
 91
 92	dev = skb->dev;
 93
 94	rcu_read_lock();
 95
 96	if (dev && skb->skb_iif)
 97		indev = dev_get_by_index_rcu(dev_net(dev), skb->skb_iif);
 98
 99	acpar.in      = indev ? indev : dev;
100	acpar.out     = dev;
101
102	ret = ip_set_test(set->index, skb, &acpar, &opt);
103
104	rcu_read_unlock();
105
106	skb_push(skb, network_offset);
107	return ret;
108}
109
110static struct tcf_ematch_ops em_ipset_ops = {
111	.kind	  = TCF_EM_IPSET,
112	.change	  = em_ipset_change,
113	.destroy  = em_ipset_destroy,
114	.match	  = em_ipset_match,
115	.owner	  = THIS_MODULE,
116	.link	  = LIST_HEAD_INIT(em_ipset_ops.link)
117};
118
119static int __init init_em_ipset(void)
120{
121	return tcf_em_register(&em_ipset_ops);
122}
123
124static void __exit exit_em_ipset(void)
125{
126	tcf_em_unregister(&em_ipset_ops);
127}
128
129MODULE_LICENSE("GPL");
130MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
131MODULE_DESCRIPTION("TC extended match for IP sets");
132
133module_init(init_em_ipset);
134module_exit(exit_em_ipset);
135
136MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);