Commit | Line | Data |
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1da177e4 LT |
1 | /* Kernel module to match the bridge port in and |
2 | * out device for IP packets coming into contact with a bridge. */ | |
3 | ||
4 | /* (C) 2001-2003 Bart De Schuymer <bdschuym@pandora.be> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/skbuff.h> | |
2e4e6a17 HW |
13 | #include <linux/netfilter/xt_physdev.h> |
14 | #include <linux/netfilter/x_tables.h> | |
1da177e4 LT |
15 | #include <linux/netfilter_bridge.h> |
16 | #define MATCH 1 | |
17 | #define NOMATCH 0 | |
18 | ||
19 | MODULE_LICENSE("GPL"); | |
20 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); | |
21 | MODULE_DESCRIPTION("iptables bridge physical device match module"); | |
2e4e6a17 HW |
22 | MODULE_ALIAS("ipt_physdev"); |
23 | MODULE_ALIAS("ip6t_physdev"); | |
1da177e4 LT |
24 | |
25 | static int | |
26 | match(const struct sk_buff *skb, | |
27 | const struct net_device *in, | |
28 | const struct net_device *out, | |
c4986734 | 29 | const struct xt_match *match, |
1da177e4 LT |
30 | const void *matchinfo, |
31 | int offset, | |
32 | unsigned int protoff, | |
33 | int *hotdrop) | |
34 | { | |
35 | int i; | |
36 | static const char nulldevname[IFNAMSIZ]; | |
2e4e6a17 | 37 | const struct xt_physdev_info *info = matchinfo; |
1da177e4 LT |
38 | unsigned int ret; |
39 | const char *indev, *outdev; | |
40 | struct nf_bridge_info *nf_bridge; | |
41 | ||
42 | /* Not a bridged IP packet or no info available yet: | |
43 | * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if | |
44 | * the destination device will be a bridge. */ | |
45 | if (!(nf_bridge = skb->nf_bridge)) { | |
46 | /* Return MATCH if the invert flags of the used options are on */ | |
2e4e6a17 HW |
47 | if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && |
48 | !(info->invert & XT_PHYSDEV_OP_BRIDGED)) | |
1da177e4 | 49 | return NOMATCH; |
2e4e6a17 HW |
50 | if ((info->bitmask & XT_PHYSDEV_OP_ISIN) && |
51 | !(info->invert & XT_PHYSDEV_OP_ISIN)) | |
1da177e4 | 52 | return NOMATCH; |
2e4e6a17 HW |
53 | if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) && |
54 | !(info->invert & XT_PHYSDEV_OP_ISOUT)) | |
1da177e4 | 55 | return NOMATCH; |
2e4e6a17 HW |
56 | if ((info->bitmask & XT_PHYSDEV_OP_IN) && |
57 | !(info->invert & XT_PHYSDEV_OP_IN)) | |
1da177e4 | 58 | return NOMATCH; |
2e4e6a17 HW |
59 | if ((info->bitmask & XT_PHYSDEV_OP_OUT) && |
60 | !(info->invert & XT_PHYSDEV_OP_OUT)) | |
1da177e4 LT |
61 | return NOMATCH; |
62 | return MATCH; | |
63 | } | |
64 | ||
65 | /* This only makes sense in the FORWARD and POSTROUTING chains */ | |
2e4e6a17 | 66 | if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && |
1da177e4 | 67 | (!!(nf_bridge->mask & BRNF_BRIDGED) ^ |
2e4e6a17 | 68 | !(info->invert & XT_PHYSDEV_OP_BRIDGED))) |
1da177e4 LT |
69 | return NOMATCH; |
70 | ||
2e4e6a17 HW |
71 | if ((info->bitmask & XT_PHYSDEV_OP_ISIN && |
72 | (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) || | |
73 | (info->bitmask & XT_PHYSDEV_OP_ISOUT && | |
74 | (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT)))) | |
1da177e4 LT |
75 | return NOMATCH; |
76 | ||
2e4e6a17 | 77 | if (!(info->bitmask & XT_PHYSDEV_OP_IN)) |
1da177e4 LT |
78 | goto match_outdev; |
79 | indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname; | |
80 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) { | |
81 | ret |= (((const unsigned int *)indev)[i] | |
82 | ^ ((const unsigned int *)info->physindev)[i]) | |
83 | & ((const unsigned int *)info->in_mask)[i]; | |
84 | } | |
85 | ||
2e4e6a17 | 86 | if ((ret == 0) ^ !(info->invert & XT_PHYSDEV_OP_IN)) |
1da177e4 LT |
87 | return NOMATCH; |
88 | ||
89 | match_outdev: | |
2e4e6a17 | 90 | if (!(info->bitmask & XT_PHYSDEV_OP_OUT)) |
1da177e4 LT |
91 | return MATCH; |
92 | outdev = nf_bridge->physoutdev ? | |
93 | nf_bridge->physoutdev->name : nulldevname; | |
94 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) { | |
95 | ret |= (((const unsigned int *)outdev)[i] | |
96 | ^ ((const unsigned int *)info->physoutdev)[i]) | |
97 | & ((const unsigned int *)info->out_mask)[i]; | |
98 | } | |
99 | ||
2e4e6a17 | 100 | return (ret != 0) ^ !(info->invert & XT_PHYSDEV_OP_OUT); |
1da177e4 LT |
101 | } |
102 | ||
103 | static int | |
104 | checkentry(const char *tablename, | |
2e4e6a17 | 105 | const void *ip, |
c4986734 | 106 | const struct xt_match *match, |
1da177e4 LT |
107 | void *matchinfo, |
108 | unsigned int matchsize, | |
109 | unsigned int hook_mask) | |
110 | { | |
2e4e6a17 | 111 | const struct xt_physdev_info *info = matchinfo; |
1da177e4 | 112 | |
2e4e6a17 HW |
113 | if (!(info->bitmask & XT_PHYSDEV_OP_MASK) || |
114 | info->bitmask & ~XT_PHYSDEV_OP_MASK) | |
1da177e4 LT |
115 | return 0; |
116 | return 1; | |
117 | } | |
118 | ||
2e4e6a17 HW |
119 | static struct xt_match physdev_match = { |
120 | .name = "physdev", | |
5d04bff0 PM |
121 | .match = match, |
122 | .matchsize = sizeof(struct xt_physdev_info), | |
123 | .checkentry = checkentry, | |
a45049c5 | 124 | .family = AF_INET, |
2e4e6a17 HW |
125 | .me = THIS_MODULE, |
126 | }; | |
127 | ||
128 | static struct xt_match physdev6_match = { | |
1da177e4 | 129 | .name = "physdev", |
5d04bff0 PM |
130 | .match = match, |
131 | .matchsize = sizeof(struct xt_physdev_info), | |
132 | .checkentry = checkentry, | |
a45049c5 | 133 | .family = AF_INET6, |
1da177e4 LT |
134 | .me = THIS_MODULE, |
135 | }; | |
136 | ||
65b4b4e8 | 137 | static int __init xt_physdev_init(void) |
1da177e4 | 138 | { |
2e4e6a17 HW |
139 | int ret; |
140 | ||
a45049c5 | 141 | ret = xt_register_match(&physdev_match); |
2e4e6a17 HW |
142 | if (ret < 0) |
143 | return ret; | |
144 | ||
a45049c5 | 145 | ret = xt_register_match(&physdev6_match); |
2e4e6a17 | 146 | if (ret < 0) |
a45049c5 | 147 | xt_unregister_match(&physdev_match); |
2e4e6a17 HW |
148 | |
149 | return ret; | |
1da177e4 LT |
150 | } |
151 | ||
65b4b4e8 | 152 | static void __exit xt_physdev_fini(void) |
1da177e4 | 153 | { |
a45049c5 PNA |
154 | xt_unregister_match(&physdev_match); |
155 | xt_unregister_match(&physdev6_match); | |
1da177e4 LT |
156 | } |
157 | ||
65b4b4e8 AM |
158 | module_init(xt_physdev_init); |
159 | module_exit(xt_physdev_fini); |