1/* 2 * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT . 3 * 4 * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> 5 */ 6#include <linux/module.h> 7#include <linux/netfilter_ipv4/ip_tables.h> 8#include <linux/slab.h> 9#include <net/ip.h> 10 11#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT)) 12 13static const struct xt_table packet_raw = { 14 .name = "raw", 15 .valid_hooks = RAW_VALID_HOOKS, 16 .me = THIS_MODULE, 17 .af = NFPROTO_IPV4, 18 .priority = NF_IP_PRI_RAW, 19}; 20 21/* The work comes in here from netfilter.c. */ 22static unsigned int 23iptable_raw_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, 24 const struct nf_hook_state *state) 25{ 26 const struct net *net; 27 28 if (ops->hooknum == NF_INET_LOCAL_OUT && 29 (skb->len < sizeof(struct iphdr) || 30 ip_hdrlen(skb) < sizeof(struct iphdr))) 31 /* root is playing with raw sockets. */ 32 return NF_ACCEPT; 33 34 net = dev_net(state->in ? state->in : state->out); 35 return ipt_do_table(skb, ops->hooknum, state, net->ipv4.iptable_raw); 36} 37 38static struct nf_hook_ops *rawtable_ops __read_mostly; 39 40static int __net_init iptable_raw_net_init(struct net *net) 41{ 42 struct ipt_replace *repl; 43 44 repl = ipt_alloc_initial_table(&packet_raw); 45 if (repl == NULL) 46 return -ENOMEM; 47 net->ipv4.iptable_raw = 48 ipt_register_table(net, &packet_raw, repl); 49 kfree(repl); 50 return PTR_ERR_OR_ZERO(net->ipv4.iptable_raw); 51} 52 53static void __net_exit iptable_raw_net_exit(struct net *net) 54{ 55 ipt_unregister_table(net, net->ipv4.iptable_raw); 56} 57 58static struct pernet_operations iptable_raw_net_ops = { 59 .init = iptable_raw_net_init, 60 .exit = iptable_raw_net_exit, 61}; 62 63static int __init iptable_raw_init(void) 64{ 65 int ret; 66 67 ret = register_pernet_subsys(&iptable_raw_net_ops); 68 if (ret < 0) 69 return ret; 70 71 /* Register hooks */ 72 rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook); 73 if (IS_ERR(rawtable_ops)) { 74 ret = PTR_ERR(rawtable_ops); 75 unregister_pernet_subsys(&iptable_raw_net_ops); 76 } 77 78 return ret; 79} 80 81static void __exit iptable_raw_fini(void) 82{ 83 xt_hook_unlink(&packet_raw, rawtable_ops); 84 unregister_pernet_subsys(&iptable_raw_net_ops); 85} 86 87module_init(iptable_raw_init); 88module_exit(iptable_raw_fini); 89MODULE_LICENSE("GPL"); 90