1/*
2 *  ebt_mark
3 *
4 *	Authors:
5 *	Bart De Schuymer <bdschuym@pandora.be>
6 *
7 *  July, 2002
8 *
9 */
10
11/* The mark target can be used in any chain,
12 * I believe adding a mangle table just for marking is total overkill.
13 * Marking a frame doesn't really change anything in the frame anyway.
14 */
15
16#include <linux/module.h>
17#include <linux/netfilter/x_tables.h>
18#include <linux/netfilter_bridge/ebtables.h>
19#include <linux/netfilter_bridge/ebt_mark_t.h>
20
21static unsigned int
22ebt_mark_tg(struct sk_buff *skb, const struct xt_action_param *par)
23{
24	const struct ebt_mark_t_info *info = par->targinfo;
25	int action = info->target & -16;
26
27	if (action == MARK_SET_VALUE)
28		skb->mark = info->mark;
29	else if (action == MARK_OR_VALUE)
30		skb->mark |= info->mark;
31	else if (action == MARK_AND_VALUE)
32		skb->mark &= info->mark;
33	else
34		skb->mark ^= info->mark;
35
36	return info->target | ~EBT_VERDICT_BITS;
37}
38
39static int ebt_mark_tg_check(const struct xt_tgchk_param *par)
40{
41	const struct ebt_mark_t_info *info = par->targinfo;
42	int tmp;
43
44	tmp = info->target | ~EBT_VERDICT_BITS;
45	if (BASE_CHAIN && tmp == EBT_RETURN)
46		return -EINVAL;
47	if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
48		return -EINVAL;
49	tmp = info->target & ~EBT_VERDICT_BITS;
50	if (tmp != MARK_SET_VALUE && tmp != MARK_OR_VALUE &&
51	    tmp != MARK_AND_VALUE && tmp != MARK_XOR_VALUE)
52		return -EINVAL;
53	return 0;
54}
55#ifdef CONFIG_COMPAT
56struct compat_ebt_mark_t_info {
57	compat_ulong_t mark;
58	compat_uint_t target;
59};
60
61static void mark_tg_compat_from_user(void *dst, const void *src)
62{
63	const struct compat_ebt_mark_t_info *user = src;
64	struct ebt_mark_t_info *kern = dst;
65
66	kern->mark = user->mark;
67	kern->target = user->target;
68}
69
70static int mark_tg_compat_to_user(void __user *dst, const void *src)
71{
72	struct compat_ebt_mark_t_info __user *user = dst;
73	const struct ebt_mark_t_info *kern = src;
74
75	if (put_user(kern->mark, &user->mark) ||
76	    put_user(kern->target, &user->target))
77		return -EFAULT;
78	return 0;
79}
80#endif
81
82static struct xt_target ebt_mark_tg_reg __read_mostly = {
83	.name		= "mark",
84	.revision	= 0,
85	.family		= NFPROTO_BRIDGE,
86	.target		= ebt_mark_tg,
87	.checkentry	= ebt_mark_tg_check,
88	.targetsize	= sizeof(struct ebt_mark_t_info),
89#ifdef CONFIG_COMPAT
90	.compatsize	= sizeof(struct compat_ebt_mark_t_info),
91	.compat_from_user = mark_tg_compat_from_user,
92	.compat_to_user	= mark_tg_compat_to_user,
93#endif
94	.me		= THIS_MODULE,
95};
96
97static int __init ebt_mark_init(void)
98{
99	return xt_register_target(&ebt_mark_tg_reg);
100}
101
102static void __exit ebt_mark_fini(void)
103{
104	xt_unregister_target(&ebt_mark_tg_reg);
105}
106
107module_init(ebt_mark_init);
108module_exit(ebt_mark_fini);
109MODULE_DESCRIPTION("Ebtables: Packet mark modification");
110MODULE_LICENSE("GPL");
111