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
|
/* This kernel module is used to modify the connection mark values, or
* to optionally restore the skb nfmark from the connection mark
*
* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
* by Henrik Nordstrom <hno@marasystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/checksum.h>
MODULE_AUTHOR("Henrik Nordstrom <hno@marasytems.com>");
MODULE_DESCRIPTION("IP tables CONNMARK matching module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_CONNMARK");
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_CONNMARK.h>
#include <net/netfilter/nf_conntrack_compat.h>
static unsigned int
target(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct xt_connmark_target_info *markinfo = targinfo;
u_int32_t diff;
u_int32_t nfmark;
u_int32_t newmark;
u_int32_t ctinfo;
u_int32_t *ctmark = nf_ct_get_mark(*pskb, &ctinfo);
if (ctmark) {
switch(markinfo->mode) {
case XT_CONNMARK_SET:
newmark = (*ctmark & ~markinfo->mask) | markinfo->mark;
if (newmark != *ctmark)
*ctmark = newmark;
break;
case XT_CONNMARK_SAVE:
newmark = (*ctmark & ~markinfo->mask) | ((*pskb)->nfmark & markinfo->mask);
if (*ctmark != newmark)
*ctmark = newmark;
break;
case XT_CONNMARK_RESTORE:
nfmark = (*pskb)->nfmark;
diff = (*ctmark ^ nfmark) & markinfo->mask;
if (diff != 0)
(*pskb)->nfmark = nfmark ^ diff;
break;
}
}
return XT_CONTINUE;
}
static int
checkentry(const char *tablename,
const void *entry,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
struct xt_connmark_target_info *matchinfo = targinfo;
if (matchinfo->mode == XT_CONNMARK_RESTORE) {
if (strcmp(tablename, "mangle") != 0) {
printk(KERN_WARNING "CONNMARK: restore can only be called from \"mangle\" table, not \"%s\"\n", tablename);
return 0;
}
}
if (matchinfo->mark > 0xffffffff || matchinfo->mask > 0xffffffff) {
printk(KERN_WARNING "CONNMARK: Only supports 32bit mark\n");
return 0;
}
return 1;
}
static struct xt_target connmark_reg = {
.name = "CONNMARK",
.target = target,
.targetsize = sizeof(struct xt_connmark_target_info),
.checkentry = checkentry,
.me = THIS_MODULE
};
static struct xt_target connmark6_reg = {
.name = "CONNMARK",
.target = target,
.targetsize = sizeof(struct xt_connmark_target_info),
.checkentry = checkentry,
.me = THIS_MODULE
};
static int __init init(void)
{
int ret;
need_conntrack();
ret = xt_register_target(AF_INET, &connmark_reg);
if (ret)
return ret;
ret = xt_register_target(AF_INET6, &connmark6_reg);
if (ret)
xt_unregister_target(AF_INET, &connmark_reg);
return ret;
}
static void __exit fini(void)
{
xt_unregister_target(AF_INET, &connmark_reg);
xt_unregister_target(AF_INET6, &connmark6_reg);
}
module_init(init);
module_exit(fini);
|
