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	int ret, network_offset;
61
62	switch (tc_skb_protocol(skb)) {
63	case htons(ETH_P_IP):
64		acpar.family = NFPROTO_IPV4;
65		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
66			return 0;
67		acpar.thoff = ip_hdrlen(skb);
68		break;
69	case htons(ETH_P_IPV6):
70		acpar.family = NFPROTO_IPV6;
71		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
72			return 0;
73		/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
74		acpar.thoff = sizeof(struct ipv6hdr);
75		break;
76	default:
77		return 0;
78	}
79
80	acpar.hooknum = 0;
81
82	opt.family = acpar.family;
83	opt.dim = set->dim;
84	opt.flags = set->flags;
85	opt.cmdflags = 0;
86	opt.ext.timeout = ~0u;
87
88	network_offset = skb_network_offset(skb);
89	skb_pull(skb, network_offset);
90
91	dev = skb->dev;
92
93	rcu_read_lock();
94
95	if (skb->skb_iif)
96		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
97
98	acpar.net     = em->net;
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);
137