1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. 4 * 5 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 6 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/moduleparam.h> 11 #include <linux/netfilter_ipv6/ip6_tables.h> 12 #include <linux/slab.h> 13 14 MODULE_LICENSE("GPL"); 15 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 16 MODULE_DESCRIPTION("ip6tables filter table"); 17 18 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \ 19 (1 << NF_INET_FORWARD) | \ 20 (1 << NF_INET_LOCAL_OUT)) 21 22 static const struct xt_table packet_filter = { 23 .name = "filter", 24 .valid_hooks = FILTER_VALID_HOOKS, 25 .me = THIS_MODULE, 26 .af = NFPROTO_IPV6, 27 .priority = NF_IP6_PRI_FILTER, 28 }; 29 30 static struct nf_hook_ops *filter_ops __read_mostly; 31 32 /* Default to forward because I got too much mail already. */ 33 static bool forward = true; 34 module_param(forward, bool, 0000); 35 36 static int ip6table_filter_table_init(struct net *net) 37 { 38 struct ip6t_replace *repl; 39 int err; 40 41 repl = ip6t_alloc_initial_table(&packet_filter); 42 if (repl == NULL) 43 return -ENOMEM; 44 /* Entry 1 is the FORWARD hook */ 45 ((struct ip6t_standard *)repl->entries)[1].target.verdict = 46 forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; 47 48 err = ip6t_register_table(net, &packet_filter, repl, filter_ops); 49 kfree(repl); 50 return err; 51 } 52 53 static int __net_init ip6table_filter_net_init(struct net *net) 54 { 55 if (!forward) 56 return ip6table_filter_table_init(net); 57 58 return 0; 59 } 60 61 static void __net_exit ip6table_filter_net_pre_exit(struct net *net) 62 { 63 ip6t_unregister_table_pre_exit(net, "filter"); 64 } 65 66 static void __net_exit ip6table_filter_net_exit(struct net *net) 67 { 68 ip6t_unregister_table_exit(net, "filter"); 69 } 70 71 static struct pernet_operations ip6table_filter_net_ops = { 72 .init = ip6table_filter_net_init, 73 .pre_exit = ip6table_filter_net_pre_exit, 74 .exit = ip6table_filter_net_exit, 75 }; 76 77 static int __init ip6table_filter_init(void) 78 { 79 int ret = xt_register_template(&packet_filter, 80 ip6table_filter_table_init); 81 82 if (ret < 0) 83 return ret; 84 85 filter_ops = xt_hook_ops_alloc(&packet_filter, ip6t_do_table); 86 if (IS_ERR(filter_ops)) { 87 xt_unregister_template(&packet_filter); 88 return PTR_ERR(filter_ops); 89 } 90 91 ret = register_pernet_subsys(&ip6table_filter_net_ops); 92 if (ret < 0) { 93 xt_unregister_template(&packet_filter); 94 kfree(filter_ops); 95 return ret; 96 } 97 98 return ret; 99 } 100 101 static void __exit ip6table_filter_fini(void) 102 { 103 unregister_pernet_subsys(&ip6table_filter_net_ops); 104 xt_unregister_template(&packet_filter); 105 kfree(filter_ops); 106 } 107 108 module_init(ip6table_filter_init); 109 module_exit(ip6table_filter_fini); 110