netfilter: xtables: move extension arguments into compound structure (2/6)
[linux-3.10.git] / net / netfilter / xt_physdev.c
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>
13 #include <linux/netfilter_bridge.h>
14 #include <linux/netfilter/xt_physdev.h>
15 #include <linux/netfilter/x_tables.h>
16
17 MODULE_LICENSE("GPL");
18 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
19 MODULE_DESCRIPTION("Xtables: Bridge physical device match");
20 MODULE_ALIAS("ipt_physdev");
21 MODULE_ALIAS("ip6t_physdev");
22
23 static bool
24 physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par)
25 {
26         int i;
27         static const char nulldevname[IFNAMSIZ];
28         const struct xt_physdev_info *info = par->matchinfo;
29         bool ret;
30         const char *indev, *outdev;
31         const struct nf_bridge_info *nf_bridge;
32
33         /* Not a bridged IP packet or no info available yet:
34          * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if
35          * the destination device will be a bridge. */
36         if (!(nf_bridge = skb->nf_bridge)) {
37                 /* Return MATCH if the invert flags of the used options are on */
38                 if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
39                     !(info->invert & XT_PHYSDEV_OP_BRIDGED))
40                         return false;
41                 if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
42                     !(info->invert & XT_PHYSDEV_OP_ISIN))
43                         return false;
44                 if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
45                     !(info->invert & XT_PHYSDEV_OP_ISOUT))
46                         return false;
47                 if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
48                     !(info->invert & XT_PHYSDEV_OP_IN))
49                         return false;
50                 if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
51                     !(info->invert & XT_PHYSDEV_OP_OUT))
52                         return false;
53                 return true;
54         }
55
56         /* This only makes sense in the FORWARD and POSTROUTING chains */
57         if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
58             (!!(nf_bridge->mask & BRNF_BRIDGED) ^
59             !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
60                 return false;
61
62         if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
63             (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
64             (info->bitmask & XT_PHYSDEV_OP_ISOUT &&
65             (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
66                 return false;
67
68         if (!(info->bitmask & XT_PHYSDEV_OP_IN))
69                 goto match_outdev;
70         indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname;
71         for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) {
72                 ret |= (((const unsigned int *)indev)[i]
73                         ^ ((const unsigned int *)info->physindev)[i])
74                         & ((const unsigned int *)info->in_mask)[i];
75         }
76
77         if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
78                 return false;
79
80 match_outdev:
81         if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
82                 return true;
83         outdev = nf_bridge->physoutdev ?
84                  nf_bridge->physoutdev->name : nulldevname;
85         for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) {
86                 ret |= (((const unsigned int *)outdev)[i]
87                         ^ ((const unsigned int *)info->physoutdev)[i])
88                         & ((const unsigned int *)info->out_mask)[i];
89         }
90
91         return ret ^ !(info->invert & XT_PHYSDEV_OP_OUT);
92 }
93
94 static bool physdev_mt_check(const struct xt_mtchk_param *par)
95 {
96         const struct xt_physdev_info *info = par->matchinfo;
97
98         if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
99             info->bitmask & ~XT_PHYSDEV_OP_MASK)
100                 return false;
101         if (info->bitmask & XT_PHYSDEV_OP_OUT &&
102             (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
103              info->invert & XT_PHYSDEV_OP_BRIDGED) &&
104             par->hook_mask & ((1 << NF_INET_LOCAL_OUT) |
105             (1 << NF_INET_FORWARD) | (1 << NF_INET_POST_ROUTING))) {
106                 printk(KERN_WARNING "physdev match: using --physdev-out in the "
107                        "OUTPUT, FORWARD and POSTROUTING chains for non-bridged "
108                        "traffic is not supported anymore.\n");
109                 if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
110                         return false;
111         }
112         return true;
113 }
114
115 static struct xt_match physdev_mt_reg[] __read_mostly = {
116         {
117                 .name           = "physdev",
118                 .family         = NFPROTO_IPV4,
119                 .checkentry     = physdev_mt_check,
120                 .match          = physdev_mt,
121                 .matchsize      = sizeof(struct xt_physdev_info),
122                 .me             = THIS_MODULE,
123         },
124         {
125                 .name           = "physdev",
126                 .family         = NFPROTO_IPV6,
127                 .checkentry     = physdev_mt_check,
128                 .match          = physdev_mt,
129                 .matchsize      = sizeof(struct xt_physdev_info),
130                 .me             = THIS_MODULE,
131         },
132 };
133
134 static int __init physdev_mt_init(void)
135 {
136         return xt_register_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));
137 }
138
139 static void __exit physdev_mt_exit(void)
140 {
141         xt_unregister_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));
142 }
143
144 module_init(physdev_mt_init);
145 module_exit(physdev_mt_exit);