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
21 static unsigned int
ebt_mark_tg(struct sk_buff * skb,const struct xt_target_param * par)22 ebt_mark_tg(struct sk_buff *skb, const struct xt_target_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
ebt_mark_tg_check(const struct xt_tgchk_param * par)39 static bool 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 false;
47 if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
48 return false;
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 false;
53 return true;
54 }
55
56 static struct xt_target ebt_mark_tg_reg __read_mostly = {
57 .name = "mark",
58 .revision = 0,
59 .family = NFPROTO_BRIDGE,
60 .target = ebt_mark_tg,
61 .checkentry = ebt_mark_tg_check,
62 .targetsize = XT_ALIGN(sizeof(struct ebt_mark_t_info)),
63 .me = THIS_MODULE,
64 };
65
ebt_mark_init(void)66 static int __init ebt_mark_init(void)
67 {
68 return xt_register_target(&ebt_mark_tg_reg);
69 }
70
ebt_mark_fini(void)71 static void __exit ebt_mark_fini(void)
72 {
73 xt_unregister_target(&ebt_mark_tg_reg);
74 }
75
76 module_init(ebt_mark_init);
77 module_exit(ebt_mark_fini);
78 MODULE_DESCRIPTION("Ebtables: Packet mark modification");
79 MODULE_LICENSE("GPL");
80