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
22 static unsigned int
ebt_mark_tg(struct sk_buff * skb,const struct xt_action_param * par)23 ebt_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
ebt_mark_tg_check(const struct xt_tgchk_param * par)40 static 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(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
57 struct compat_ebt_mark_t_info {
58 compat_ulong_t mark;
59 compat_uint_t target;
60 };
61
mark_tg_compat_from_user(void * dst,const void * src)62 static 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
mark_tg_compat_to_user(void __user * dst,const void * src)71 static 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
83 static 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
ebt_mark_init(void)98 static int __init ebt_mark_init(void)
99 {
100 return xt_register_target(&ebt_mark_tg_reg);
101 }
102
ebt_mark_fini(void)103 static void __exit ebt_mark_fini(void)
104 {
105 xt_unregister_target(&ebt_mark_tg_reg);
106 }
107
108 module_init(ebt_mark_init);
109 module_exit(ebt_mark_fini);
110 MODULE_DESCRIPTION("Ebtables: Packet mark modification");
111 MODULE_LICENSE("GPL");
112
