tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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 __be32 ipaddr;
45
46 /* packets in either direction go into same queue */
47 ipaddr = iph->saddr ^ iph->daddr;
48
49 return jhash_2words((__force u32)ipaddr, iph->protocol, jhash_initval);
50}
51
52#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
53static u32 hash_v6(const struct sk_buff *skb)
54{
55 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
56 __be32 addr[4];
57
58 addr[0] = ip6h->saddr.s6_addr32[0] ^ ip6h->daddr.s6_addr32[0];
59 addr[1] = ip6h->saddr.s6_addr32[1] ^ ip6h->daddr.s6_addr32[1];
60 addr[2] = ip6h->saddr.s6_addr32[2] ^ ip6h->daddr.s6_addr32[2];
61 addr[3] = ip6h->saddr.s6_addr32[3] ^ ip6h->daddr.s6_addr32[3];
62
63 return jhash2((__force u32 *)addr, ARRAY_SIZE(addr), jhash_initval);
64}
65#endif
66
67static unsigned int
68nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
69{
70 const struct xt_NFQ_info_v1 *info = par->targinfo;
71 u32 queue = info->queuenum;
72
73 if (info->queues_total > 1) {
74 if (par->family == NFPROTO_IPV4)
75 queue = hash_v4(skb) % info->queues_total + queue;
76#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
77 else if (par->family == NFPROTO_IPV6)
78 queue = hash_v6(skb) % info->queues_total + queue;
79#endif
80 }
81 return NF_QUEUE_NR(queue);
82}
83
84static int nfqueue_tg_v1_check(const struct xt_tgchk_param *par)
85{
86 const struct xt_NFQ_info_v1 *info = par->targinfo;
87 u32 maxid;
88
89 if (unlikely(!rnd_inited)) {
90 get_random_bytes(&jhash_initval, sizeof(jhash_initval));
91 rnd_inited = true;
92 }
93 if (info->queues_total == 0) {
94 pr_err("NFQUEUE: number of total queues is 0\n");
95 return -EINVAL;
96 }
97 maxid = info->queues_total - 1 + info->queuenum;
98 if (maxid > 0xffff) {
99 pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
100 info->queues_total, maxid);
101 return -ERANGE;
102 }
103 return 0;
104}
105
106static struct xt_target nfqueue_tg_reg[] __read_mostly = {
107 {
108 .name = "NFQUEUE",
109 .family = NFPROTO_UNSPEC,
110 .target = nfqueue_tg,
111 .targetsize = sizeof(struct xt_NFQ_info),
112 .me = THIS_MODULE,
113 },
114 {
115 .name = "NFQUEUE",
116 .revision = 1,
117 .family = NFPROTO_UNSPEC,
118 .checkentry = nfqueue_tg_v1_check,
119 .target = nfqueue_tg_v1,
120 .targetsize = sizeof(struct xt_NFQ_info_v1),
121 .me = THIS_MODULE,
122 },
123};
124
125static int __init nfqueue_tg_init(void)
126{
127 return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
128}
129
130static void __exit nfqueue_tg_exit(void)
131{
132 xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
133}
134
135module_init(nfqueue_tg_init);
136module_exit(nfqueue_tg_exit);