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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> | |
deb47c66 | 13 | #include <linux/netfilter_bridge.h> |
2e4e6a17 HW |
14 | #include <linux/netfilter/xt_physdev.h> |
15 | #include <linux/netfilter/x_tables.h> | |
1da177e4 LT |
16 | |
17 | MODULE_LICENSE("GPL"); | |
18 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); | |
2ae15b64 | 19 | MODULE_DESCRIPTION("Xtables: Bridge physical device match"); |
2e4e6a17 HW |
20 | MODULE_ALIAS("ipt_physdev"); |
21 | MODULE_ALIAS("ip6t_physdev"); | |
1da177e4 | 22 | |
1d93a9cb | 23 | static bool |
d3c5ee6d JE |
24 | physdev_mt(const struct sk_buff *skb, const struct net_device *in, |
25 | const struct net_device *out, const struct xt_match *match, | |
26 | const void *matchinfo, int offset, unsigned int protoff, | |
27 | bool *hotdrop) | |
1da177e4 LT |
28 | { |
29 | int i; | |
30 | static const char nulldevname[IFNAMSIZ]; | |
2e4e6a17 | 31 | const struct xt_physdev_info *info = matchinfo; |
1d93a9cb | 32 | bool ret; |
1da177e4 | 33 | const char *indev, *outdev; |
a47362a2 | 34 | const struct nf_bridge_info *nf_bridge; |
1da177e4 LT |
35 | |
36 | /* Not a bridged IP packet or no info available yet: | |
37 | * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if | |
38 | * the destination device will be a bridge. */ | |
39 | if (!(nf_bridge = skb->nf_bridge)) { | |
40 | /* Return MATCH if the invert flags of the used options are on */ | |
2e4e6a17 HW |
41 | if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && |
42 | !(info->invert & XT_PHYSDEV_OP_BRIDGED)) | |
1d93a9cb | 43 | return false; |
2e4e6a17 HW |
44 | if ((info->bitmask & XT_PHYSDEV_OP_ISIN) && |
45 | !(info->invert & XT_PHYSDEV_OP_ISIN)) | |
1d93a9cb | 46 | return false; |
2e4e6a17 HW |
47 | if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) && |
48 | !(info->invert & XT_PHYSDEV_OP_ISOUT)) | |
1d93a9cb | 49 | return false; |
2e4e6a17 HW |
50 | if ((info->bitmask & XT_PHYSDEV_OP_IN) && |
51 | !(info->invert & XT_PHYSDEV_OP_IN)) | |
1d93a9cb | 52 | return false; |
2e4e6a17 HW |
53 | if ((info->bitmask & XT_PHYSDEV_OP_OUT) && |
54 | !(info->invert & XT_PHYSDEV_OP_OUT)) | |
1d93a9cb JE |
55 | return false; |
56 | return true; | |
1da177e4 LT |
57 | } |
58 | ||
59 | /* This only makes sense in the FORWARD and POSTROUTING chains */ | |
2e4e6a17 | 60 | if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && |
1da177e4 | 61 | (!!(nf_bridge->mask & BRNF_BRIDGED) ^ |
2e4e6a17 | 62 | !(info->invert & XT_PHYSDEV_OP_BRIDGED))) |
1d93a9cb | 63 | return false; |
1da177e4 | 64 | |
2e4e6a17 HW |
65 | if ((info->bitmask & XT_PHYSDEV_OP_ISIN && |
66 | (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) || | |
67 | (info->bitmask & XT_PHYSDEV_OP_ISOUT && | |
68 | (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT)))) | |
1d93a9cb | 69 | return false; |
1da177e4 | 70 | |
2e4e6a17 | 71 | if (!(info->bitmask & XT_PHYSDEV_OP_IN)) |
1da177e4 LT |
72 | goto match_outdev; |
73 | indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname; | |
1d93a9cb | 74 | for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) { |
1da177e4 LT |
75 | ret |= (((const unsigned int *)indev)[i] |
76 | ^ ((const unsigned int *)info->physindev)[i]) | |
77 | & ((const unsigned int *)info->in_mask)[i]; | |
78 | } | |
79 | ||
1d93a9cb JE |
80 | if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN)) |
81 | return false; | |
1da177e4 LT |
82 | |
83 | match_outdev: | |
2e4e6a17 | 84 | if (!(info->bitmask & XT_PHYSDEV_OP_OUT)) |
1d93a9cb | 85 | return true; |
1da177e4 LT |
86 | outdev = nf_bridge->physoutdev ? |
87 | nf_bridge->physoutdev->name : nulldevname; | |
1d93a9cb | 88 | for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) { |
1da177e4 LT |
89 | ret |= (((const unsigned int *)outdev)[i] |
90 | ^ ((const unsigned int *)info->physoutdev)[i]) | |
91 | & ((const unsigned int *)info->out_mask)[i]; | |
92 | } | |
93 | ||
1d93a9cb | 94 | return ret ^ !(info->invert & XT_PHYSDEV_OP_OUT); |
1da177e4 LT |
95 | } |
96 | ||
ccb79bdc | 97 | static bool |
d3c5ee6d JE |
98 | physdev_mt_check(const char *tablename, const void *ip, |
99 | const struct xt_match *match, void *matchinfo, | |
100 | unsigned int hook_mask) | |
1da177e4 | 101 | { |
2e4e6a17 | 102 | const struct xt_physdev_info *info = matchinfo; |
1da177e4 | 103 | |
2e4e6a17 HW |
104 | if (!(info->bitmask & XT_PHYSDEV_OP_MASK) || |
105 | info->bitmask & ~XT_PHYSDEV_OP_MASK) | |
ccb79bdc | 106 | return false; |
2bf540b7 | 107 | if (info->bitmask & XT_PHYSDEV_OP_OUT && |
10ea6ac8 PM |
108 | (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) || |
109 | info->invert & XT_PHYSDEV_OP_BRIDGED) && | |
6e23ae2a PM |
110 | hook_mask & ((1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_FORWARD) | |
111 | (1 << NF_INET_POST_ROUTING))) { | |
10ea6ac8 PM |
112 | printk(KERN_WARNING "physdev match: using --physdev-out in the " |
113 | "OUTPUT, FORWARD and POSTROUTING chains for non-bridged " | |
2bf540b7 | 114 | "traffic is not supported anymore.\n"); |
6e23ae2a | 115 | if (hook_mask & (1 << NF_INET_LOCAL_OUT)) |
ccb79bdc | 116 | return false; |
10ea6ac8 | 117 | } |
ccb79bdc | 118 | return true; |
1da177e4 LT |
119 | } |
120 | ||
d3c5ee6d | 121 | static struct xt_match physdev_mt_reg[] __read_mostly = { |
4470bbc7 PM |
122 | { |
123 | .name = "physdev", | |
124 | .family = AF_INET, | |
d3c5ee6d JE |
125 | .checkentry = physdev_mt_check, |
126 | .match = physdev_mt, | |
4470bbc7 PM |
127 | .matchsize = sizeof(struct xt_physdev_info), |
128 | .me = THIS_MODULE, | |
129 | }, | |
130 | { | |
131 | .name = "physdev", | |
132 | .family = AF_INET6, | |
d3c5ee6d JE |
133 | .checkentry = physdev_mt_check, |
134 | .match = physdev_mt, | |
4470bbc7 PM |
135 | .matchsize = sizeof(struct xt_physdev_info), |
136 | .me = THIS_MODULE, | |
137 | }, | |
1da177e4 LT |
138 | }; |
139 | ||
d3c5ee6d | 140 | static int __init physdev_mt_init(void) |
1da177e4 | 141 | { |
d3c5ee6d | 142 | return xt_register_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg)); |
1da177e4 LT |
143 | } |
144 | ||
d3c5ee6d | 145 | static void __exit physdev_mt_exit(void) |
1da177e4 | 146 | { |
d3c5ee6d | 147 | xt_unregister_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg)); |
1da177e4 LT |
148 | } |
149 | ||
d3c5ee6d JE |
150 | module_init(physdev_mt_init); |
151 | module_exit(physdev_mt_exit); |