LXR linux/net/netfilter/xt

   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
  18MODULE_LICENSE("GPL");
  19MODULE_AUTHOR("Eric Dumazet <eric.dumazet@gmail.com>");
  20MODULE_DESCRIPTION("Xtables: CPU match");
  21MODULE_ALIAS("ipt_cpu");
  22MODULE_ALIAS("ip6t_cpu");
  23
  24static 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
  33static 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
  40static 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
  50static int __init cpu_mt_init(void)
  51{
  52        return xt_register_match(&cpu_mt_reg);
  53}
  54
  55static void __exit cpu_mt_exit(void)
  56{
  57        xt_unregister_match(&cpu_mt_reg);
  58}
  59
  60module_init(cpu_mt_init);
  61module_exit(cpu_mt_exit);
  62