| /* |
| * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT . |
| * |
| * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| */ |
| #include <linux/module.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| #include <net/ip.h> |
| |
| #define RAW_VALID_HOOKS ((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT)) |
| |
| static struct |
| { |
| struct ipt_replace repl; |
| struct ipt_standard entries[2]; |
| struct ipt_error term; |
| } initial_table __initdata = { |
| .repl = { |
| .name = "raw", |
| .valid_hooks = RAW_VALID_HOOKS, |
| .num_entries = 3, |
| .size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error), |
| .hook_entry = { |
| [NF_IP_PRE_ROUTING] = 0, |
| [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) |
| }, |
| .underflow = { |
| [NF_IP_PRE_ROUTING] = 0, |
| [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) |
| }, |
| }, |
| .entries = { |
| IPT_STANDARD_INIT(NF_ACCEPT), /* PRE_ROUTING */ |
| IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */ |
| }, |
| .term = IPT_ERROR_INIT, /* ERROR */ |
| }; |
| |
| static struct xt_table packet_raw = { |
| .name = "raw", |
| .valid_hooks = RAW_VALID_HOOKS, |
| .lock = RW_LOCK_UNLOCKED, |
| .me = THIS_MODULE, |
| .af = AF_INET, |
| }; |
| |
| /* The work comes in here from netfilter.c. */ |
| static unsigned int |
| ipt_hook(unsigned int hook, |
| struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| return ipt_do_table(skb, hook, in, out, &packet_raw); |
| } |
| |
| static unsigned int |
| ipt_local_hook(unsigned int hook, |
| struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| /* root is playing with raw sockets. */ |
| if (skb->len < sizeof(struct iphdr) || |
| ip_hdrlen(skb) < sizeof(struct iphdr)) { |
| if (net_ratelimit()) |
| printk("iptable_raw: ignoring short SOCK_RAW " |
| "packet.\n"); |
| return NF_ACCEPT; |
| } |
| return ipt_do_table(skb, hook, in, out, &packet_raw); |
| } |
| |
| /* 'raw' is the very first table. */ |
| static struct nf_hook_ops ipt_ops[] = { |
| { |
| .hook = ipt_hook, |
| .pf = PF_INET, |
| .hooknum = NF_IP_PRE_ROUTING, |
| .priority = NF_IP_PRI_RAW, |
| .owner = THIS_MODULE, |
| }, |
| { |
| .hook = ipt_local_hook, |
| .pf = PF_INET, |
| .hooknum = NF_IP_LOCAL_OUT, |
| .priority = NF_IP_PRI_RAW, |
| .owner = THIS_MODULE, |
| }, |
| }; |
| |
| static int __init iptable_raw_init(void) |
| { |
| int ret; |
| |
| /* Register table */ |
| ret = ipt_register_table(&packet_raw, &initial_table.repl); |
| if (ret < 0) |
| return ret; |
| |
| /* Register hooks */ |
| ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
| if (ret < 0) |
| goto cleanup_table; |
| |
| return ret; |
| |
| cleanup_table: |
| ipt_unregister_table(&packet_raw); |
| return ret; |
| } |
| |
| static void __exit iptable_raw_fini(void) |
| { |
| nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
| ipt_unregister_table(&packet_raw); |
| } |
| |
| module_init(iptable_raw_init); |
| module_exit(iptable_raw_fini); |
| MODULE_LICENSE("GPL"); |