Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* IP tables module for matching the routing realm |
| 2 | * |
| 3 | * $Id: ipt_realm.c,v 1.3 2004/03/05 13:25:40 laforge Exp $ |
| 4 | * |
| 5 | * (C) 2003 by Sampsa Ranta <sampsa@netsonic.fi> |
| 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/skbuff.h> |
| 14 | #include <linux/netdevice.h> |
| 15 | #include <net/route.h> |
| 16 | |
| 17 | #include <linux/netfilter_ipv4/ipt_realm.h> |
| 18 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 19 | |
| 20 | MODULE_AUTHOR("Sampsa Ranta <sampsa@netsonic.fi>"); |
| 21 | MODULE_LICENSE("GPL"); |
| 22 | MODULE_DESCRIPTION("iptables realm match"); |
| 23 | |
| 24 | static int |
| 25 | match(const struct sk_buff *skb, |
| 26 | const struct net_device *in, |
| 27 | const struct net_device *out, |
| 28 | const void *matchinfo, |
| 29 | int offset, |
| 30 | int *hotdrop) |
| 31 | { |
| 32 | const struct ipt_realm_info *info = matchinfo; |
| 33 | struct dst_entry *dst = skb->dst; |
| 34 | |
| 35 | return (info->id == (dst->tclassid & info->mask)) ^ info->invert; |
| 36 | } |
| 37 | |
| 38 | static int check(const char *tablename, |
| 39 | const struct ipt_ip *ip, |
| 40 | void *matchinfo, |
| 41 | unsigned int matchsize, |
| 42 | unsigned int hook_mask) |
| 43 | { |
| 44 | if (hook_mask |
| 45 | & ~((1 << NF_IP_POST_ROUTING) | (1 << NF_IP_FORWARD) | |
| 46 | (1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_LOCAL_IN))) { |
| 47 | printk("ipt_realm: only valid for POST_ROUTING, LOCAL_OUT, " |
| 48 | "LOCAL_IN or FORWARD.\n"); |
| 49 | return 0; |
| 50 | } |
| 51 | if (matchsize != IPT_ALIGN(sizeof(struct ipt_realm_info))) { |
| 52 | printk("ipt_realm: invalid matchsize.\n"); |
| 53 | return 0; |
| 54 | } |
| 55 | return 1; |
| 56 | } |
| 57 | |
| 58 | static struct ipt_match realm_match = { |
| 59 | .name = "realm", |
| 60 | .match = match, |
| 61 | .checkentry = check, |
| 62 | .me = THIS_MODULE |
| 63 | }; |
| 64 | |
| 65 | static int __init init(void) |
| 66 | { |
| 67 | return ipt_register_match(&realm_match); |
| 68 | } |
| 69 | |
| 70 | static void __exit fini(void) |
| 71 | { |
| 72 | ipt_unregister_match(&realm_match); |
| 73 | } |
| 74 | |
| 75 | module_init(init); |
| 76 | module_exit(fini); |