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
21 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
22 MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
23 MODULE_LICENSE("GPL");
24 MODULE_ALIAS("ipt_NFQUEUE");
25 MODULE_ALIAS("ip6t_NFQUEUE");
26 MODULE_ALIAS("arpt_NFQUEUE");
27
28 static u32 jhash_initval __read_mostly;
29
30 static unsigned int
nfqueue_tg(struct sk_buff * skb,const struct xt_action_param * par)31 nfqueue_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
38 static unsigned int
nfqueue_tg_v1(struct sk_buff * skb,const struct xt_action_param * par)39 nfqueue_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
51 static unsigned int
nfqueue_tg_v2(struct sk_buff * skb,const struct xt_action_param * par)52 nfqueue_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
nfqueue_tg_check(const struct xt_tgchk_param * par)62 static 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
87 static unsigned int
nfqueue_tg_v3(struct sk_buff * skb,const struct xt_action_param * par)88 nfqueue_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
112 static 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
nfqueue_tg_init(void)149 static int __init nfqueue_tg_init(void)
150 {
151 return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
152 }
153
nfqueue_tg_exit(void)154 static void __exit nfqueue_tg_exit(void)
155 {
156 xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
157 }
158
159 module_init(nfqueue_tg_init);
160 module_exit(nfqueue_tg_exit);
161