1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Kernel module to match running CPU */
3
4 /*
5 * Might be used to distribute connections on several daemons, if
6 * RPS (Remote Packet Steering) is enabled or NIC is multiqueue capable,
7 * each RX queue IRQ affined to one CPU (1:1 mapping)
8 */
9
10 /* (C) 2010 Eric Dumazet
11 */
12
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/netfilter/xt_cpu.h>
16 #include <linux/netfilter/x_tables.h>
17
18 MODULE_LICENSE("GPL");
19 MODULE_AUTHOR("Eric Dumazet <eric.dumazet@gmail.com>");
20 MODULE_DESCRIPTION("Xtables: CPU match");
21 MODULE_ALIAS("ipt_cpu");
22 MODULE_ALIAS("ip6t_cpu");
23
cpu_mt_check(const struct xt_mtchk_param * par)24 static int cpu_mt_check(const struct xt_mtchk_param *par)
25 {
26 const struct xt_cpu_info *info = par->matchinfo;
27
28 if (info->invert & ~1)
29 return -EINVAL;
30 return 0;
31 }
32
cpu_mt(const struct sk_buff * skb,struct xt_action_param * par)33 static bool cpu_mt(const struct sk_buff *skb, struct xt_action_param *par)
34 {
35 const struct xt_cpu_info *info = par->matchinfo;
36
37 return (info->cpu == smp_processor_id()) ^ info->invert;
38 }
39
40 static struct xt_match cpu_mt_reg __read_mostly = {
41 .name = "cpu",
42 .revision = 0,
43 .family = NFPROTO_UNSPEC,
44 .checkentry = cpu_mt_check,
45 .match = cpu_mt,
46 .matchsize = sizeof(struct xt_cpu_info),
47 .me = THIS_MODULE,
48 };
49
cpu_mt_init(void)50 static int __init cpu_mt_init(void)
51 {
52 return xt_register_match(&cpu_mt_reg);
53 }
54
cpu_mt_exit(void)55 static void __exit cpu_mt_exit(void)
56 {
57 xt_unregister_match(&cpu_mt_reg);
58 }
59
60 module_init(cpu_mt_init);
61 module_exit(cpu_mt_exit);
62