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
|
/* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter/xt_physdev.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/br_netfilter.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
MODULE_DESCRIPTION("Xtables: Bridge physical device match");
MODULE_ALIAS("ipt_physdev");
MODULE_ALIAS("ip6t_physdev");
static bool
physdev_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_physdev_info *info = par->matchinfo;
const struct net_device *physdev;
unsigned long ret;
const char *indev, *outdev;
/* 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 (!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 false;
if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
!(info->invert & XT_PHYSDEV_OP_ISIN))
return false;
if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
!(info->invert & XT_PHYSDEV_OP_ISOUT))
return false;
if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
!(info->invert & XT_PHYSDEV_OP_IN))
return false;
if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
!(info->invert & XT_PHYSDEV_OP_OUT))
return false;
return true;
}
physdev = nf_bridge_get_physoutdev(skb);
outdev = physdev ? physdev->name : NULL;
/* This only makes sense in the FORWARD and POSTROUTING chains */
if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
(!!outdev ^ !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
return false;
physdev = nf_bridge_get_physindev(skb);
indev = physdev ? physdev->name : NULL;
if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
(!indev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
(info->bitmask & XT_PHYSDEV_OP_ISOUT &&
(!outdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
return false;
if (!(info->bitmask & XT_PHYSDEV_OP_IN))
goto match_outdev;
if (indev) {
ret = ifname_compare_aligned(indev, info->physindev,
info->in_mask);
if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
return false;
}
match_outdev:
if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
return true;
if (!outdev)
return false;
ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask);
return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));
}
static int physdev_mt_check(const struct xt_mtchk_param *par)
{
const struct xt_physdev_info *info = par->matchinfo;
br_netfilter_enable();
if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
info->bitmask & ~XT_PHYSDEV_OP_MASK)
return -EINVAL;
if (info->bitmask & (XT_PHYSDEV_OP_OUT | XT_PHYSDEV_OP_ISOUT) &&
(!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
info->invert & XT_PHYSDEV_OP_BRIDGED) &&
par->hook_mask & ((1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_FORWARD) | (1 << NF_INET_POST_ROUTING))) {
pr_info("using --physdev-out and --physdev-is-out are only"
"supported in the FORWARD and POSTROUTING chains with"
"bridged traffic.\n");
if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
return -EINVAL;
}
return 0;
}
static struct xt_match physdev_mt_reg __read_mostly = {
.name = "physdev",
.revision = 0,
.family = NFPROTO_UNSPEC,
.checkentry = physdev_mt_check,
.match = physdev_mt,
.matchsize = sizeof(struct xt_physdev_info),
.me = THIS_MODULE,
};
static int __init physdev_mt_init(void)
{
return xt_register_match(&physdev_mt_reg);
}
static void __exit physdev_mt_exit(void)
{
xt_unregister_match(&physdev_mt_reg);
}
module_init(physdev_mt_init);
module_exit(physdev_mt_exit);
|
