1// SPDX-License-Identifier: GPL-2.0-only
2/* iptables module for using new netfilter netlink queue
3 *
4 * (C) 2005 by Harald Welte <laforge@netfilter.org>
5 */
6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/module.h>
10#include <linux/skbuff.h>
11
12#include <linux/netfilter.h>
13#include <linux/netfilter_arp.h>
14#include <linux/netfilter/x_tables.h>
15#include <linux/netfilter/xt_NFQUEUE.h>
16
17#include <net/netfilter/nf_queue.h>
18
19MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
20MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
21MODULE_LICENSE("GPL");
22MODULE_ALIAS("ipt_NFQUEUE");
23MODULE_ALIAS("ip6t_NFQUEUE");
24MODULE_ALIAS("arpt_NFQUEUE");
25
26static u32 jhash_initval __read_mostly;
27
28static unsigned int
29nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
30{
31 const struct xt_NFQ_info *tinfo = par->targinfo;
32
33 return NF_QUEUE_NR(tinfo->queuenum);
34}
35
36static unsigned int
37nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
38{
39 const struct xt_NFQ_info_v1 *info = par->targinfo;
40 u32 queue = info->queuenum;
41
42 if (info->queues_total > 1) {
43 queue = nfqueue_hash(skb, queue, queues_total: info->queues_total,
44 family: xt_family(par), initval: jhash_initval);
45 }
46 return NF_QUEUE_NR(queue);
47}
48
49static unsigned int
50nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
51{
52 const struct xt_NFQ_info_v2 *info = par->targinfo;
53 unsigned int ret = nfqueue_tg_v1(skb, par);
54
55 if (info->bypass)
56 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
57 return ret;
58}
59
60static int nfqueue_tg_check(const struct xt_tgchk_param *par)
61{
62 const struct xt_NFQ_info_v3 *info = par->targinfo;
63 u32 maxid;
64
65 init_hashrandom(jhash_initval: &jhash_initval);
66
67 if (info->queues_total == 0) {
68 pr_info_ratelimited("number of total queues is 0\n");
69 return -EINVAL;
70 }
71 maxid = info->queues_total - 1 + info->queuenum;
72 if (maxid > 0xffff) {
73 pr_info_ratelimited("number of queues (%u) out of range (got %u)\n",
74 info->queues_total, maxid);
75 return -ERANGE;
76 }
77 if (par->target->revision == 2 && info->flags > 1)
78 return -EINVAL;
79 if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK)
80 return -EINVAL;
81
82 return 0;
83}
84
85static unsigned int
86nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par)
87{
88 const struct xt_NFQ_info_v3 *info = par->targinfo;
89 u32 queue = info->queuenum;
90 int ret;
91
92 if (info->queues_total > 1) {
93 if (info->flags & NFQ_FLAG_CPU_FANOUT) {
94 int cpu = smp_processor_id();
95
96 queue = info->queuenum + cpu % info->queues_total;
97 } else {
98 queue = nfqueue_hash(skb, queue, queues_total: info->queues_total,
99 family: xt_family(par), initval: jhash_initval);
100 }
101 }
102
103 ret = NF_QUEUE_NR(queue);
104 if (info->flags & NFQ_FLAG_BYPASS)
105 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
106
107 return ret;
108}
109
110static struct xt_target nfqueue_tg_reg[] __read_mostly = {
111 {
112 .name = "NFQUEUE",
113 .family = NFPROTO_UNSPEC,
114 .target = nfqueue_tg,
115 .targetsize = sizeof(struct xt_NFQ_info),
116 .me = THIS_MODULE,
117 },
118 {
119 .name = "NFQUEUE",
120 .revision = 1,
121 .family = NFPROTO_UNSPEC,
122 .checkentry = nfqueue_tg_check,
123 .target = nfqueue_tg_v1,
124 .targetsize = sizeof(struct xt_NFQ_info_v1),
125 .me = THIS_MODULE,
126 },
127 {
128 .name = "NFQUEUE",
129 .revision = 2,
130 .family = NFPROTO_UNSPEC,
131 .checkentry = nfqueue_tg_check,
132 .target = nfqueue_tg_v2,
133 .targetsize = sizeof(struct xt_NFQ_info_v2),
134 .me = THIS_MODULE,
135 },
136 {
137 .name = "NFQUEUE",
138 .revision = 3,
139 .family = NFPROTO_UNSPEC,
140 .checkentry = nfqueue_tg_check,
141 .target = nfqueue_tg_v3,
142 .targetsize = sizeof(struct xt_NFQ_info_v3),
143 .me = THIS_MODULE,
144 },
145};
146
147static int __init nfqueue_tg_init(void)
148{
149 return xt_register_targets(target: nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
150}
151
152static void __exit nfqueue_tg_exit(void)
153{
154 xt_unregister_targets(target: nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
155}
156
157module_init(nfqueue_tg_init);
158module_exit(nfqueue_tg_exit);
159

source code of linux/net/netfilter/xt_NFQUEUE.c