| /* |
| * Filtering ARP tables module. |
| * |
| * Copyright (C) 2002 David S. Miller (davem@redhat.com) |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/netfilter/x_tables.h> |
| #include <linux/netfilter_arp/arp_tables.h> |
| #include <linux/slab.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); |
| MODULE_DESCRIPTION("arptables filter table"); |
| |
| #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ |
| (1 << NF_ARP_FORWARD)) |
| |
| static const struct xt_table packet_filter = { |
| .name = "filter", |
| .valid_hooks = FILTER_VALID_HOOKS, |
| .me = THIS_MODULE, |
| .af = NFPROTO_ARP, |
| .priority = NF_IP_PRI_FILTER, |
| }; |
| |
| /* The work comes in here from netfilter.c */ |
| static unsigned int |
| arptable_filter_hook(unsigned int hook, struct sk_buff *skb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| const struct net *net = dev_net((in != NULL) ? in : out); |
| |
| return arpt_do_table(skb, hook, in, out, net->ipv4.arptable_filter); |
| } |
| |
| static struct nf_hook_ops *arpfilter_ops __read_mostly; |
| |
| static int __net_init arptable_filter_net_init(struct net *net) |
| { |
| struct arpt_replace *repl; |
| |
| repl = arpt_alloc_initial_table(&packet_filter); |
| if (repl == NULL) |
| return -ENOMEM; |
| net->ipv4.arptable_filter = |
| arpt_register_table(net, &packet_filter, repl); |
| kfree(repl); |
| return PTR_RET(net->ipv4.arptable_filter); |
| } |
| |
| static void __net_exit arptable_filter_net_exit(struct net *net) |
| { |
| arpt_unregister_table(net->ipv4.arptable_filter); |
| } |
| |
| static struct pernet_operations arptable_filter_net_ops = { |
| .init = arptable_filter_net_init, |
| .exit = arptable_filter_net_exit, |
| }; |
| |
| static int __init arptable_filter_init(void) |
| { |
| int ret; |
| |
| ret = register_pernet_subsys(&arptable_filter_net_ops); |
| if (ret < 0) |
| return ret; |
| |
| arpfilter_ops = xt_hook_link(&packet_filter, arptable_filter_hook); |
| if (IS_ERR(arpfilter_ops)) { |
| ret = PTR_ERR(arpfilter_ops); |
| goto cleanup_table; |
| } |
| return ret; |
| |
| cleanup_table: |
| unregister_pernet_subsys(&arptable_filter_net_ops); |
| return ret; |
| } |
| |
| static void __exit arptable_filter_fini(void) |
| { |
| xt_hook_unlink(&packet_filter, arpfilter_ops); |
| unregister_pernet_subsys(&arptable_filter_net_ops); |
| } |
| |
| module_init(arptable_filter_init); |
| module_exit(arptable_filter_fini); |