1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ebt_mark
4 *
5 * Authors:
6 * Bart De Schuymer <bdschuym@pandora.be>
7 *
8 * July, 2002
9 *
10 */
11
12/* The mark target can be used in any chain,
13 * I believe adding a mangle table just for marking is total overkill.
14 * Marking a frame doesn't really change anything in the frame anyway.
15 */
16
17#include <linux/module.h>
18#include <linux/netfilter/x_tables.h>
19#include <linux/netfilter_bridge/ebtables.h>
20#include <linux/netfilter_bridge/ebt_mark_t.h>
21
22static unsigned int
23ebt_mark_tg(struct sk_buff *skb, const struct xt_action_param *par)
24{
25 const struct ebt_mark_t_info *info = par->targinfo;
26 int action = info->target & -16;
27
28 if (action == MARK_SET_VALUE)
29 skb->mark = info->mark;
30 else if (action == MARK_OR_VALUE)
31 skb->mark |= info->mark;
32 else if (action == MARK_AND_VALUE)
33 skb->mark &= info->mark;
34 else
35 skb->mark ^= info->mark;
36
37 return info->target | ~EBT_VERDICT_BITS;
38}
39
40static int ebt_mark_tg_check(const struct xt_tgchk_param *par)
41{
42 const struct ebt_mark_t_info *info = par->targinfo;
43 int tmp;
44
45 tmp = info->target | ~EBT_VERDICT_BITS;
46 if (BASE_CHAIN && tmp == EBT_RETURN)
47 return -EINVAL;
48 if (ebt_invalid_target(target: tmp))
49 return -EINVAL;
50 tmp = info->target & ~EBT_VERDICT_BITS;
51 if (tmp != MARK_SET_VALUE && tmp != MARK_OR_VALUE &&
52 tmp != MARK_AND_VALUE && tmp != MARK_XOR_VALUE)
53 return -EINVAL;
54 return 0;
55}
56#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
57struct compat_ebt_mark_t_info {
58 compat_ulong_t mark;
59 compat_uint_t target;
60};
61
62static void mark_tg_compat_from_user(void *dst, const void *src)
63{
64 const struct compat_ebt_mark_t_info *user = src;
65 struct ebt_mark_t_info *kern = dst;
66
67 kern->mark = user->mark;
68 kern->target = user->target;
69}
70
71static int mark_tg_compat_to_user(void __user *dst, const void *src)
72{
73 struct compat_ebt_mark_t_info __user *user = dst;
74 const struct ebt_mark_t_info *kern = src;
75
76 if (put_user(kern->mark, &user->mark) ||
77 put_user(kern->target, &user->target))
78 return -EFAULT;
79 return 0;
80}
81#endif
82
83static struct xt_target ebt_mark_tg_reg __read_mostly = {
84 .name = "mark",
85 .revision = 0,
86 .family = NFPROTO_BRIDGE,
87 .target = ebt_mark_tg,
88 .checkentry = ebt_mark_tg_check,
89 .targetsize = sizeof(struct ebt_mark_t_info),
90#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
91 .compatsize = sizeof(struct compat_ebt_mark_t_info),
92 .compat_from_user = mark_tg_compat_from_user,
93 .compat_to_user = mark_tg_compat_to_user,
94#endif
95 .me = THIS_MODULE,
96};
97
98static int __init ebt_mark_init(void)
99{
100 return xt_register_target(target: &ebt_mark_tg_reg);
101}
102
103static void __exit ebt_mark_fini(void)
104{
105 xt_unregister_target(target: &ebt_mark_tg_reg);
106}
107
108module_init(ebt_mark_init);
109module_exit(ebt_mark_fini);
110MODULE_DESCRIPTION("Ebtables: Packet mark modification");
111MODULE_LICENSE("GPL");
112

source code of linux/net/bridge/netfilter/ebt_mark.c