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
|
/* Kernel module to match the bridge port in and
* out device for IP packets coming into contact with a bridge. */
/* (C) 2001-2003 Bart De Schuymer <bdschuym@pandora.be>
*
* 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/netfilter/xt_physdev.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge.h>
#define MATCH 1
#define NOMATCH 0
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
MODULE_DESCRIPTION("iptables bridge physical device match module");
MODULE_ALIAS("ipt_physdev");
MODULE_ALIAS("ip6t_physdev");
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct xt_match *match,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
int i;
static const char nulldevname[IFNAMSIZ];
const struct xt_physdev_info *info = matchinfo;
unsigned int ret;
const char *indev, *outdev;
struct nf_bridge_info *nf_bridge;
/* Not a bridged IP packet or no info available yet:
* LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if
* the destination device will be a bridge. */
if (!(nf_bridge = skb->nf_bridge)) {
/* Return MATCH if the invert flags of the used options are on */
if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
!(info->invert & XT_PHYSDEV_OP_BRIDGED))
return NOMATCH;
if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
!(info->invert & XT_PHYSDEV_OP_ISIN))
return NOMATCH;
if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
!(info->invert & XT_PHYSDEV_OP_ISOUT))
return NOMATCH;
if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
!(info->invert & XT_PHYSDEV_OP_IN))
return NOMATCH;
if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
!(info->invert & XT_PHYSDEV_OP_OUT))
return NOMATCH;
return MATCH;
}
/* This only makes sense in the FORWARD and POSTROUTING chains */
if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
(!!(nf_bridge->mask & BRNF_BRIDGED) ^
!(info->invert & XT_PHYSDEV_OP_BRIDGED)))
return NOMATCH;
if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
(!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
(info->bitmask & XT_PHYSDEV_OP_ISOUT &&
(!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
return NOMATCH;
if (!(info->bitmask & XT_PHYSDEV_OP_IN))
goto match_outdev;
indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname;
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
ret |= (((const unsigned int *)indev)[i]
^ ((const unsigned int *)info->physindev)[i])
& ((const unsigned int *)info->in_mask)[i];
}
if ((ret == 0) ^ !(info->invert & XT_PHYSDEV_OP_IN))
return NOMATCH;
match_outdev:
if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
return MATCH;
outdev = nf_bridge->physoutdev ?
nf_bridge->physoutdev->name : nulldevname;
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
ret |= (((const unsigned int *)outdev)[i]
^ ((const unsigned int *)info->physoutdev)[i])
& ((const unsigned int *)info->out_mask)[i];
}
return (ret != 0) ^ !(info->invert & XT_PHYSDEV_OP_OUT);
}
static int
checkentry(const char *tablename,
const void *ip,
const struct xt_match *match,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
const struct xt_physdev_info *info = matchinfo;
if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
info->bitmask & ~XT_PHYSDEV_OP_MASK)
return 0;
return 1;
}
static struct xt_match physdev_match = {
.name = "physdev",
.match = match,
.matchsize = sizeof(struct xt_physdev_info),
.checkentry = checkentry,
.family = AF_INET,
.me = THIS_MODULE,
};
static struct xt_match physdev6_match = {
.name = "physdev",
.match = match,
.matchsize = sizeof(struct xt_physdev_info),
.checkentry = checkentry,
.family = AF_INET6,
.me = THIS_MODULE,
};
static int __init init(void)
{
int ret;
ret = xt_register_match(&physdev_match);
if (ret < 0)
return ret;
ret = xt_register_match(&physdev6_match);
if (ret < 0)
xt_unregister_match(&physdev_match);
return ret;
}
static void __exit fini(void)
{
xt_unregister_match(&physdev_match);
xt_unregister_match(&physdev6_match);
}
module_init(init);
module_exit(fini);
|
