Patrick McHardy | 9291747 | 2011-02-03 00:05:43 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/skbuff.h> |
| 11 | #include <linux/netdevice.h> |
| 12 | |
| 13 | #include <linux/netfilter/xt_devgroup.h> |
| 14 | #include <linux/netfilter/x_tables.h> |
| 15 | |
| 16 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 17 | MODULE_LICENSE("GPL"); |
| 18 | MODULE_DESCRIPTION("Xtables: Device group match"); |
| 19 | MODULE_ALIAS("ipt_devgroup"); |
| 20 | MODULE_ALIAS("ip6t_devgroup"); |
| 21 | |
| 22 | static bool devgroup_mt(const struct sk_buff *skb, struct xt_action_param *par) |
| 23 | { |
| 24 | const struct xt_devgroup_info *info = par->matchinfo; |
| 25 | |
| 26 | if (info->flags & XT_DEVGROUP_MATCH_SRC && |
| 27 | (((info->src_group ^ par->in->group) & info->src_mask ? 1 : 0) ^ |
| 28 | ((info->flags & XT_DEVGROUP_INVERT_SRC) ? 1 : 0))) |
| 29 | return false; |
| 30 | |
| 31 | if (info->flags & XT_DEVGROUP_MATCH_DST && |
| 32 | (((info->dst_group ^ par->out->group) & info->dst_mask ? 1 : 0) ^ |
| 33 | ((info->flags & XT_DEVGROUP_INVERT_DST) ? 1 : 0))) |
| 34 | return false; |
| 35 | |
| 36 | return true; |
| 37 | } |
| 38 | |
| 39 | static int devgroup_mt_checkentry(const struct xt_mtchk_param *par) |
| 40 | { |
| 41 | const struct xt_devgroup_info *info = par->matchinfo; |
| 42 | |
| 43 | if (info->flags & ~(XT_DEVGROUP_MATCH_SRC | XT_DEVGROUP_INVERT_SRC | |
| 44 | XT_DEVGROUP_MATCH_DST | XT_DEVGROUP_INVERT_DST)) |
| 45 | return -EINVAL; |
| 46 | |
| 47 | if (info->flags & XT_DEVGROUP_MATCH_SRC && |
| 48 | par->hook_mask & ~((1 << NF_INET_PRE_ROUTING) | |
| 49 | (1 << NF_INET_LOCAL_IN) | |
| 50 | (1 << NF_INET_FORWARD))) |
| 51 | return -EINVAL; |
| 52 | |
| 53 | if (info->flags & XT_DEVGROUP_MATCH_DST && |
| 54 | par->hook_mask & ~((1 << NF_INET_FORWARD) | |
| 55 | (1 << NF_INET_LOCAL_OUT) | |
| 56 | (1 << NF_INET_POST_ROUTING))) |
| 57 | return -EINVAL; |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static struct xt_match devgroup_mt_reg __read_mostly = { |
| 63 | .name = "devgroup", |
| 64 | .match = devgroup_mt, |
| 65 | .checkentry = devgroup_mt_checkentry, |
| 66 | .matchsize = sizeof(struct xt_devgroup_info), |
| 67 | .family = NFPROTO_UNSPEC, |
| 68 | .me = THIS_MODULE |
| 69 | }; |
| 70 | |
| 71 | static int __init devgroup_mt_init(void) |
| 72 | { |
| 73 | return xt_register_match(&devgroup_mt_reg); |
| 74 | } |
| 75 | |
| 76 | static void __exit devgroup_mt_exit(void) |
| 77 | { |
| 78 | xt_unregister_match(&devgroup_mt_reg); |
| 79 | } |
| 80 | |
| 81 | module_init(devgroup_mt_init); |
| 82 | module_exit(devgroup_mt_exit); |