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 int __net_init ip6table_filter_table_init(struct net *net); 23 24 static const struct xt_table packet_filter = { 25 .name = "filter", 26 .valid_hooks = FILTER_VALID_HOOKS, 27 .me = THIS_MODULE, 28 .af = NFPROTO_IPV6, 29 .priority = NF_IP6_PRI_FILTER, 30 .table_init = ip6table_filter_table_init, 31 }; 32 33 /* The work comes in here from netfilter.c. */ 34 static unsigned int 35 ip6table_filter_hook(void *priv, struct sk_buff *skb, 36 const struct nf_hook_state *state) 37 { 38 return ip6t_do_table(skb, state, priv); 39 } 40 41 static struct nf_hook_ops *filter_ops __read_mostly; 42 43 /* Default to forward because I got too much mail already. */ 44 static bool forward = true; 45 module_param(forward, bool, 0000); 46 47 static int __net_init ip6table_filter_table_init(struct net *net) 48 { 49 struct ip6t_replace *repl; 50 int err; 51 52 repl = ip6t_alloc_initial_table(&packet_filter); 53 if (repl == NULL) 54 return -ENOMEM; 55 /* Entry 1 is the FORWARD hook */ 56 ((struct ip6t_standard *)repl->entries)[1].target.verdict = 57 forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; 58 59 err = ip6t_register_table(net, &packet_filter, repl, filter_ops); 60 kfree(repl); 61 return err; 62 } 63 64 static int __net_init ip6table_filter_net_init(struct net *net) 65 { 66 if (net == &init_net || !forward) 67 return ip6table_filter_table_init(net); 68 69 return 0; 70 } 71 72 static void __net_exit ip6table_filter_net_pre_exit(struct net *net) 73 { 74 ip6t_unregister_table_pre_exit(net, "filter"); 75 } 76 77 static void __net_exit ip6table_filter_net_exit(struct net *net) 78 { 79 ip6t_unregister_table_exit(net, "filter"); 80 } 81 82 static struct pernet_operations ip6table_filter_net_ops = { 83 .init = ip6table_filter_net_init, 84 .pre_exit = ip6table_filter_net_pre_exit, 85 .exit = ip6table_filter_net_exit, 86 }; 87 88 static int __init ip6table_filter_init(void) 89 { 90 int ret; 91 92 filter_ops = xt_hook_ops_alloc(&packet_filter, ip6table_filter_hook); 93 if (IS_ERR(filter_ops)) 94 return PTR_ERR(filter_ops); 95 96 ret = register_pernet_subsys(&ip6table_filter_net_ops); 97 if (ret < 0) 98 kfree(filter_ops); 99 100 return ret; 101 } 102 103 static void __exit ip6table_filter_fini(void) 104 { 105 unregister_pernet_subsys(&ip6table_filter_net_ops); 106 kfree(filter_ops); 107 } 108 109 module_init(ip6table_filter_init); 110 module_exit(ip6table_filter_fini); 111