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 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 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 50 static int __init cpu_mt_init(void) 51 { 52 return xt_register_match(&cpu_mt_reg); 53 } 54 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