tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * xt_CONNMARK - Netfilter module to modify the connection mark values
3 *
4 * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
5 * by Henrik Nordstrom <hno@marasystems.com>
6 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
7 * Jan Engelhardt <jengelh@computergmbh.de>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/skbuff.h>
25#include <linux/ip.h>
26#include <net/checksum.h>
27
28MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
29MODULE_DESCRIPTION("Xtables: connection mark modification");
30MODULE_LICENSE("GPL");
31MODULE_ALIAS("ipt_CONNMARK");
32MODULE_ALIAS("ip6t_CONNMARK");
33
34#include <linux/netfilter/x_tables.h>
35#include <linux/netfilter/xt_CONNMARK.h>
36#include <net/netfilter/nf_conntrack_ecache.h>
37
38static unsigned int
39connmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
40{
41 const struct xt_connmark_tginfo1 *info = par->targinfo;
42 enum ip_conntrack_info ctinfo;
43 struct nf_conn *ct;
44 u_int32_t newmark;
45
46 ct = nf_ct_get(skb, &ctinfo);
47 if (ct == NULL)
48 return XT_CONTINUE;
49
50 switch (info->mode) {
51 case XT_CONNMARK_SET:
52 newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
53 if (ct->mark != newmark) {
54 ct->mark = newmark;
55 nf_conntrack_event_cache(IPCT_MARK, ct);
56 }
57 break;
58 case XT_CONNMARK_SAVE:
59 newmark = (ct->mark & ~info->ctmask) ^
60 (skb->mark & info->nfmask);
61 if (ct->mark != newmark) {
62 ct->mark = newmark;
63 nf_conntrack_event_cache(IPCT_MARK, ct);
64 }
65 break;
66 case XT_CONNMARK_RESTORE:
67 newmark = (skb->mark & ~info->nfmask) ^
68 (ct->mark & info->ctmask);
69 skb->mark = newmark;
70 break;
71 }
72
73 return XT_CONTINUE;
74}
75
76static bool connmark_tg_check(const struct xt_tgchk_param *par)
77{
78 if (nf_ct_l3proto_try_module_get(par->family) < 0) {
79 printk(KERN_WARNING "cannot load conntrack support for "
80 "proto=%u\n", par->family);
81 return false;
82 }
83 return true;
84}
85
86static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
87{
88 nf_ct_l3proto_module_put(par->family);
89}
90
91static struct xt_target connmark_tg_reg __read_mostly = {
92 .name = "CONNMARK",
93 .revision = 1,
94 .family = NFPROTO_UNSPEC,
95 .checkentry = connmark_tg_check,
96 .target = connmark_tg,
97 .targetsize = sizeof(struct xt_connmark_tginfo1),
98 .destroy = connmark_tg_destroy,
99 .me = THIS_MODULE,
100};
101
102static int __init connmark_tg_init(void)
103{
104 return xt_register_target(&connmark_tg_reg);
105}
106
107static void __exit connmark_tg_exit(void)
108{
109 xt_unregister_target(&connmark_tg_reg);
110}
111
112module_init(connmark_tg_init);
113module_exit(connmark_tg_exit);