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 13 static 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. */ 22 static unsigned int 23 iptable_raw_hook(void *priv, struct sk_buff *skb, 24 const struct nf_hook_state *state) 25 { 26 if (state->hook == NF_INET_LOCAL_OUT && 27 (skb->len < sizeof(struct iphdr) || 28 ip_hdrlen(skb) < sizeof(struct iphdr))) 29 /* root is playing with raw sockets. */ 30 return NF_ACCEPT; 31 32 return ipt_do_table(skb, state, state->net->ipv4.iptable_raw); 33 } 34 35 static struct nf_hook_ops *rawtable_ops __read_mostly; 36 37 static int __net_init iptable_raw_net_init(struct net *net) 38 { 39 struct ipt_replace *repl; 40 41 repl = ipt_alloc_initial_table(&packet_raw); 42 if (repl == NULL) 43 return -ENOMEM; 44 net->ipv4.iptable_raw = 45 ipt_register_table(net, &packet_raw, repl); 46 kfree(repl); 47 return PTR_ERR_OR_ZERO(net->ipv4.iptable_raw); 48 } 49 50 static void __net_exit iptable_raw_net_exit(struct net *net) 51 { 52 ipt_unregister_table(net, net->ipv4.iptable_raw); 53 } 54 55 static struct pernet_operations iptable_raw_net_ops = { 56 .init = iptable_raw_net_init, 57 .exit = iptable_raw_net_exit, 58 }; 59 60 static int __init iptable_raw_init(void) 61 { 62 int ret; 63 64 ret = register_pernet_subsys(&iptable_raw_net_ops); 65 if (ret < 0) 66 return ret; 67 68 /* Register hooks */ 69 rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook); 70 if (IS_ERR(rawtable_ops)) { 71 ret = PTR_ERR(rawtable_ops); 72 unregister_pernet_subsys(&iptable_raw_net_ops); 73 } 74 75 return ret; 76 } 77 78 static void __exit iptable_raw_fini(void) 79 { 80 xt_hook_unlink(&packet_raw, rawtable_ops); 81 unregister_pernet_subsys(&iptable_raw_net_ops); 82 } 83 84 module_init(iptable_raw_init); 85 module_exit(iptable_raw_fini); 86 MODULE_LICENSE("GPL"); 87