1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/* This is a module which is used for setting the NFMARK field of an skb. */
/* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_MARK.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("iptables MARK modification module");
static unsigned int
target_v0(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct ipt_mark_target_info *markinfo = targinfo;
if((*pskb)->nfmark != markinfo->mark) {
(*pskb)->nfmark = markinfo->mark;
(*pskb)->nfcache |= NFC_ALTERED;
}
return IPT_CONTINUE;
}
static unsigned int
target_v1(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct ipt_mark_target_info_v1 *markinfo = targinfo;
int mark = 0;
switch (markinfo->mode) {
case IPT_MARK_SET:
mark = markinfo->mark;
break;
case IPT_MARK_AND:
mark = (*pskb)->nfmark & markinfo->mark;
break;
case IPT_MARK_OR:
mark = (*pskb)->nfmark | markinfo->mark;
break;
}
if((*pskb)->nfmark != mark) {
(*pskb)->nfmark = mark;
(*pskb)->nfcache |= NFC_ALTERED;
}
return IPT_CONTINUE;
}
static int
checkentry_v0(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_mark_target_info))) {
printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
targinfosize,
IPT_ALIGN(sizeof(struct ipt_mark_target_info)));
return 0;
}
if (strcmp(tablename, "mangle") != 0) {
printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
return 0;
}
return 1;
}
static int
checkentry_v1(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
struct ipt_mark_target_info_v1 *markinfo = targinfo;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_mark_target_info_v1))){
printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
targinfosize,
IPT_ALIGN(sizeof(struct ipt_mark_target_info_v1)));
return 0;
}
if (strcmp(tablename, "mangle") != 0) {
printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
return 0;
}
if (markinfo->mode != IPT_MARK_SET
&& markinfo->mode != IPT_MARK_AND
&& markinfo->mode != IPT_MARK_OR) {
printk(KERN_WARNING "MARK: unknown mode %u\n",
markinfo->mode);
return 0;
}
return 1;
}
static struct ipt_target ipt_mark_reg_v0 = {
.name = "MARK",
.target = target_v0,
.checkentry = checkentry_v0,
.me = THIS_MODULE,
.revision = 0,
};
static struct ipt_target ipt_mark_reg_v1 = {
.name = "MARK",
.target = target_v1,
.checkentry = checkentry_v1,
.me = THIS_MODULE,
.revision = 1,
};
static int __init init(void)
{
int err;
err = ipt_register_target(&ipt_mark_reg_v0);
if (!err) {
err = ipt_register_target(&ipt_mark_reg_v1);
if (err)
ipt_unregister_target(&ipt_mark_reg_v0);
}
return err;
}
static void __exit fini(void)
{
ipt_unregister_target(&ipt_mark_reg_v0);
ipt_unregister_target(&ipt_mark_reg_v1);
}
module_init(init);
module_exit(fini);
|
