1/* Kernel module to match running CPU */
2
3/*
4 * Might be used to distribute connections on several daemons, if
5 * RPS (Remote Packet Steering) is enabled or NIC is multiqueue capable,
6 * each RX queue IRQ affined to one CPU (1:1 mapping)
7 *
8 */
9
10/* (C) 2010 Eric Dumazet
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/module.h>
18#include <linux/skbuff.h>
19#include <linux/netfilter/xt_cpu.h>
20#include <linux/netfilter/x_tables.h>
21
22MODULE_LICENSE("GPL");
23MODULE_AUTHOR("Eric Dumazet <eric.dumazet@gmail.com>");
24MODULE_DESCRIPTION("Xtables: CPU match");
25MODULE_ALIAS("ipt_cpu");
26MODULE_ALIAS("ip6t_cpu");
27
28static int cpu_mt_check(const struct xt_mtchk_param *par)
29{
30	const struct xt_cpu_info *info = par->matchinfo;
31
32	if (info->invert & ~1)
33		return -EINVAL;
34	return 0;
35}
36
37static bool cpu_mt(const struct sk_buff *skb, struct xt_action_param *par)
38{
39	const struct xt_cpu_info *info = par->matchinfo;
40
41	return (info->cpu == smp_processor_id()) ^ info->invert;
42}
43
44static struct xt_match cpu_mt_reg __read_mostly = {
45	.name       = "cpu",
46	.revision   = 0,
47	.family     = NFPROTO_UNSPEC,
48	.checkentry = cpu_mt_check,
49	.match      = cpu_mt,
50	.matchsize  = sizeof(struct xt_cpu_info),
51	.me         = THIS_MODULE,
52};
53
54static int __init cpu_mt_init(void)
55{
56	return xt_register_match(&cpu_mt_reg);
57}
58
59static void __exit cpu_mt_exit(void)
60{
61	xt_unregister_match(&cpu_mt_reg);
62}
63
64module_init(cpu_mt_init);
65module_exit(cpu_mt_exit);
66