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 net *net, 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
 28	if (data_len != sizeof(*set))
 29		return -EINVAL;
 30
 31	index = ip_set_nfnl_get_byindex(net, set->index);
 32	if (index == IPSET_INVALID_ID)
 33		return -ENOENT;
 34
 35	em->datalen = sizeof(*set);
 36	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
 37	if (em->data)
 38		return 0;
 39
 40	ip_set_nfnl_put(net, index);
 41	return -ENOMEM;
 42}
 43
 44static void em_ipset_destroy(struct tcf_ematch *em)
 45{
 46	const struct xt_set_info *set = (const void *) em->data;
 47	if (set) {
 48		ip_set_nfnl_put(em->net, set->index);
 49		kfree((void *) em->data);
 50	}
 51}
 52
 53static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
 54			  struct tcf_pkt_info *info)
 55{
 56	struct ip_set_adt_opt opt;
 57	struct xt_action_param acpar;
 58	const struct xt_set_info *set = (const void *) em->data;
 59	struct net_device *dev, *indev = NULL;
 60	struct nf_hook_state state = {
 61		.net	= em->net,
 62	};
 63	int ret, network_offset;
 64
 65	switch (tc_skb_protocol(skb)) {
 66	case htons(ETH_P_IP):
 67		state.pf = NFPROTO_IPV4;
 68		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
 69			return 0;
 70		acpar.thoff = ip_hdrlen(skb);
 71		break;
 72	case htons(ETH_P_IPV6):
 73		state.pf = NFPROTO_IPV6;
 74		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
 75			return 0;
 76		/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
 77		acpar.thoff = sizeof(struct ipv6hdr);
 78		break;
 79	default:
 80		return 0;
 81	}
 82
 83	opt.family = state.pf;
 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 (skb->skb_iif)
 97		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
 98
 99	state.in      = indev ? indev : dev;
100	state.out     = dev;
101	acpar.state   = &state;
102
103	ret = ip_set_test(set->index, skb, &acpar, &opt);
104
105	rcu_read_unlock();
106
107	skb_push(skb, network_offset);
108	return ret;
109}
110
111static struct tcf_ematch_ops em_ipset_ops = {
112	.kind	  = TCF_EM_IPSET,
113	.change	  = em_ipset_change,
114	.destroy  = em_ipset_destroy,
115	.match	  = em_ipset_match,
116	.owner	  = THIS_MODULE,
117	.link	  = LIST_HEAD_INIT(em_ipset_ops.link)
118};
119
120static int __init init_em_ipset(void)
121{
122	return tcf_em_register(&em_ipset_ops);
123}
124
125static void __exit exit_em_ipset(void)
126{
127	tcf_em_unregister(&em_ipset_ops);
128}
129
130MODULE_LICENSE("GPL");
131MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
132MODULE_DESCRIPTION("TC extended match for IP sets");
133
134module_init(init_em_ipset);
135module_exit(exit_em_ipset);
136
137MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);