1 /* 2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. 3 * 4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/moduleparam.h> 14 #include <linux/netfilter_ipv6/ip6_tables.h> 15 #include <linux/slab.h> 16 17 MODULE_LICENSE("GPL"); 18 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 19 MODULE_DESCRIPTION("ip6tables filter table"); 20 21 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \ 22 (1 << NF_INET_FORWARD) | \ 23 (1 << NF_INET_LOCAL_OUT)) 24 25 static const struct xt_table packet_filter = { 26 .name = "filter", 27 .valid_hooks = FILTER_VALID_HOOKS, 28 .me = THIS_MODULE, 29 .af = NFPROTO_IPV6, 30 .priority = NF_IP6_PRI_FILTER, 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, state->net->ipv6.ip6table_filter); 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_net_init(struct net *net) 48 { 49 struct ip6t_replace *repl; 50 51 repl = ip6t_alloc_initial_table(&packet_filter); 52 if (repl == NULL) 53 return -ENOMEM; 54 /* Entry 1 is the FORWARD hook */ 55 ((struct ip6t_standard *)repl->entries)[1].target.verdict = 56 forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; 57 58 net->ipv6.ip6table_filter = 59 ip6t_register_table(net, &packet_filter, repl); 60 kfree(repl); 61 return PTR_ERR_OR_ZERO(net->ipv6.ip6table_filter); 62 } 63 64 static void __net_exit ip6table_filter_net_exit(struct net *net) 65 { 66 ip6t_unregister_table(net, net->ipv6.ip6table_filter); 67 } 68 69 static struct pernet_operations ip6table_filter_net_ops = { 70 .init = ip6table_filter_net_init, 71 .exit = ip6table_filter_net_exit, 72 }; 73 74 static int __init ip6table_filter_init(void) 75 { 76 int ret; 77 78 ret = register_pernet_subsys(&ip6table_filter_net_ops); 79 if (ret < 0) 80 return ret; 81 82 /* Register hooks */ 83 filter_ops = xt_hook_link(&packet_filter, ip6table_filter_hook); 84 if (IS_ERR(filter_ops)) { 85 ret = PTR_ERR(filter_ops); 86 goto cleanup_table; 87 } 88 89 return ret; 90 91 cleanup_table: 92 unregister_pernet_subsys(&ip6table_filter_net_ops); 93 return ret; 94 } 95 96 static void __exit ip6table_filter_fini(void) 97 { 98 xt_hook_unlink(&packet_filter, filter_ops); 99 unregister_pernet_subsys(&ip6table_filter_net_ops); 100 } 101 102 module_init(ip6table_filter_init); 103 module_exit(ip6table_filter_fini); 104