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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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/ip.h>
15#include <linux/ipv6.h>
16#include <linux/jhash.h>
17
18#include <linux/netfilter.h>
19#include <linux/netfilter_arp.h>
20#include <linux/netfilter/x_tables.h>
21#include <linux/netfilter/xt_NFQUEUE.h>
22
23MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
24MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
25MODULE_LICENSE("GPL");
26MODULE_ALIAS("ipt_NFQUEUE");
27MODULE_ALIAS("ip6t_NFQUEUE");
28MODULE_ALIAS("arpt_NFQUEUE");
29
30static u32 jhash_initval __read_mostly;
31static bool rnd_inited __read_mostly;
32
33static unsigned int
34nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
35{
36 const struct xt_NFQ_info *tinfo = par->targinfo;
37
38 return NF_QUEUE_NR(tinfo->queuenum);
39}
40
41static u32 hash_v4(const struct sk_buff *skb)
42{
43 const struct iphdr *iph = ip_hdr(skb);
44
45 /* packets in either direction go into same queue */
46 if ((__force u32)iph->saddr < (__force u32)iph->daddr)
47 return jhash_3words((__force u32)iph->saddr,
48 (__force u32)iph->daddr, iph->protocol, jhash_initval);
49
50 return jhash_3words((__force u32)iph->daddr,
51 (__force u32)iph->saddr, iph->protocol, jhash_initval);
52}
53
54#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
55static u32 hash_v6(const struct sk_buff *skb)
56{
57 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
58 u32 a, b, c;
59
60 if ((__force u32)ip6h->saddr.s6_addr32[3] <
61 (__force u32)ip6h->daddr.s6_addr32[3]) {
62 a = (__force u32) ip6h->saddr.s6_addr32[3];
63 b = (__force u32) ip6h->daddr.s6_addr32[3];
64 } else {
65 b = (__force u32) ip6h->saddr.s6_addr32[3];
66 a = (__force u32) ip6h->daddr.s6_addr32[3];
67 }
68
69 if ((__force u32)ip6h->saddr.s6_addr32[1] <
70 (__force u32)ip6h->daddr.s6_addr32[1])
71 c = (__force u32) ip6h->saddr.s6_addr32[1];
72 else
73 c = (__force u32) ip6h->daddr.s6_addr32[1];
74
75 return jhash_3words(a, b, c, jhash_initval);
76}
77#endif
78
79static unsigned int
80nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
81{
82 const struct xt_NFQ_info_v1 *info = par->targinfo;
83 u32 queue = info->queuenum;
84
85 if (info->queues_total > 1) {
86 if (par->family == NFPROTO_IPV4)
87 queue = (((u64) hash_v4(skb) * info->queues_total) >>
88 32) + queue;
89#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
90 else if (par->family == NFPROTO_IPV6)
91 queue = (((u64) hash_v6(skb) * info->queues_total) >>
92 32) + queue;
93#endif
94 }
95 return NF_QUEUE_NR(queue);
96}
97
98static unsigned int
99nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
100{
101 const struct xt_NFQ_info_v2 *info = par->targinfo;
102 unsigned int ret = nfqueue_tg_v1(skb, par);
103
104 if (info->bypass)
105 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
106 return ret;
107}
108
109static int nfqueue_tg_check(const struct xt_tgchk_param *par)
110{
111 const struct xt_NFQ_info_v2 *info = par->targinfo;
112 u32 maxid;
113
114 if (unlikely(!rnd_inited)) {
115 get_random_bytes(&jhash_initval, sizeof(jhash_initval));
116 rnd_inited = true;
117 }
118 if (info->queues_total == 0) {
119 pr_err("NFQUEUE: number of total queues is 0\n");
120 return -EINVAL;
121 }
122 maxid = info->queues_total - 1 + info->queuenum;
123 if (maxid > 0xffff) {
124 pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
125 info->queues_total, maxid);
126 return -ERANGE;
127 }
128 if (par->target->revision == 2 && info->bypass > 1)
129 return -EINVAL;
130 return 0;
131}
132
133static struct xt_target nfqueue_tg_reg[] __read_mostly = {
134 {
135 .name = "NFQUEUE",
136 .family = NFPROTO_UNSPEC,
137 .target = nfqueue_tg,
138 .targetsize = sizeof(struct xt_NFQ_info),
139 .me = THIS_MODULE,
140 },
141 {
142 .name = "NFQUEUE",
143 .revision = 1,
144 .family = NFPROTO_UNSPEC,
145 .checkentry = nfqueue_tg_check,
146 .target = nfqueue_tg_v1,
147 .targetsize = sizeof(struct xt_NFQ_info_v1),
148 .me = THIS_MODULE,
149 },
150 {
151 .name = "NFQUEUE",
152 .revision = 2,
153 .family = NFPROTO_UNSPEC,
154 .checkentry = nfqueue_tg_check,
155 .target = nfqueue_tg_v2,
156 .targetsize = sizeof(struct xt_NFQ_info_v2),
157 .me = THIS_MODULE,
158 },
159};
160
161static int __init nfqueue_tg_init(void)
162{
163 return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
164}
165
166static void __exit nfqueue_tg_exit(void)
167{
168 xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
169}
170
171module_init(nfqueue_tg_init);
172module_exit(nfqueue_tg_exit);