1/* iptables module for using new netfilter netlink queue
2 *
3 * (C) 2005 by Harald Welte <laforge@netfilter.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 */
10
11#include <linux/module.h>
12#include <linux/skbuff.h>
13
14#include <linux/netfilter.h>
15#include <linux/netfilter_arp.h>
16#include <linux/netfilter/x_tables.h>
17#include <linux/netfilter/xt_NFQUEUE.h>
18
19#include <net/netfilter/nf_queue.h>
20
21MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
22MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
23MODULE_LICENSE("GPL");
24MODULE_ALIAS("ipt_NFQUEUE");
25MODULE_ALIAS("ip6t_NFQUEUE");
26MODULE_ALIAS("arpt_NFQUEUE");
27
28static u32 jhash_initval __read_mostly;
29
30static unsigned int
31nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
32{
33	const struct xt_NFQ_info *tinfo = par->targinfo;
34
35	return NF_QUEUE_NR(tinfo->queuenum);
36}
37
38static unsigned int
39nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
40{
41	const struct xt_NFQ_info_v1 *info = par->targinfo;
42	u32 queue = info->queuenum;
43
44	if (info->queues_total > 1) {
45		queue = nfqueue_hash(skb, queue, info->queues_total,
46				     par->family, jhash_initval);
47	}
48	return NF_QUEUE_NR(queue);
49}
50
51static unsigned int
52nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
53{
54	const struct xt_NFQ_info_v2 *info = par->targinfo;
55	unsigned int ret = nfqueue_tg_v1(skb, par);
56
57	if (info->bypass)
58		ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
59	return ret;
60}
61
62static int nfqueue_tg_check(const struct xt_tgchk_param *par)
63{
64	const struct xt_NFQ_info_v3 *info = par->targinfo;
65	u32 maxid;
66
67	init_hashrandom(&jhash_initval);
68
69	if (info->queues_total == 0) {
70		pr_err("NFQUEUE: number of total queues is 0\n");
71		return -EINVAL;
72	}
73	maxid = info->queues_total - 1 + info->queuenum;
74	if (maxid > 0xffff) {
75		pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
76		       info->queues_total, maxid);
77		return -ERANGE;
78	}
79	if (par->target->revision == 2 && info->flags > 1)
80		return -EINVAL;
81	if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK)
82		return -EINVAL;
83
84	return 0;
85}
86
87static unsigned int
88nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par)
89{
90	const struct xt_NFQ_info_v3 *info = par->targinfo;
91	u32 queue = info->queuenum;
92	int ret;
93
94	if (info->queues_total > 1) {
95		if (info->flags & NFQ_FLAG_CPU_FANOUT) {
96			int cpu = smp_processor_id();
97
98			queue = info->queuenum + cpu % info->queues_total;
99		} else {
100			queue = nfqueue_hash(skb, queue, info->queues_total,
101					     par->family, jhash_initval);
102		}
103	}
104
105	ret = NF_QUEUE_NR(queue);
106	if (info->flags & NFQ_FLAG_BYPASS)
107		ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
108
109	return ret;
110}
111
112static struct xt_target nfqueue_tg_reg[] __read_mostly = {
113	{
114		.name		= "NFQUEUE",
115		.family		= NFPROTO_UNSPEC,
116		.target		= nfqueue_tg,
117		.targetsize	= sizeof(struct xt_NFQ_info),
118		.me		= THIS_MODULE,
119	},
120	{
121		.name		= "NFQUEUE",
122		.revision	= 1,
123		.family		= NFPROTO_UNSPEC,
124		.checkentry	= nfqueue_tg_check,
125		.target		= nfqueue_tg_v1,
126		.targetsize	= sizeof(struct xt_NFQ_info_v1),
127		.me		= THIS_MODULE,
128	},
129	{
130		.name		= "NFQUEUE",
131		.revision	= 2,
132		.family		= NFPROTO_UNSPEC,
133		.checkentry	= nfqueue_tg_check,
134		.target		= nfqueue_tg_v2,
135		.targetsize	= sizeof(struct xt_NFQ_info_v2),
136		.me		= THIS_MODULE,
137	},
138	{
139		.name		= "NFQUEUE",
140		.revision	= 3,
141		.family		= NFPROTO_UNSPEC,
142		.checkentry	= nfqueue_tg_check,
143		.target		= nfqueue_tg_v3,
144		.targetsize	= sizeof(struct xt_NFQ_info_v3),
145		.me		= THIS_MODULE,
146	},
147};
148
149static int __init nfqueue_tg_init(void)
150{
151	return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
152}
153
154static void __exit nfqueue_tg_exit(void)
155{
156	xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
157}
158
159module_init(nfqueue_tg_init);
160module_exit(nfqueue_tg_exit);
161