Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#include <linux/netfilter_bridge.h>
17#define MATCH 1
18#define NOMATCH 0
19
20MODULE_LICENSE("GPL");
21MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
22MODULE_DESCRIPTION("iptables bridge physical device match module");
23MODULE_ALIAS("ipt_physdev");
24MODULE_ALIAS("ip6t_physdev");
25
26static int
27match(const struct sk_buff *skb,
28 const struct net_device *in,
29 const struct net_device *out,
30 const struct xt_match *match,
31 const void *matchinfo,
32 int offset,
33 unsigned int protoff,
34 int *hotdrop)
35{
36 int i;
37 static const char nulldevname[IFNAMSIZ];
38 const struct xt_physdev_info *info = matchinfo;
39 unsigned int ret;
40 const char *indev, *outdev;
41 struct nf_bridge_info *nf_bridge;
42
43 /* Not a bridged IP packet or no info available yet:
44 * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if
45 * the destination device will be a bridge. */
46 if (!(nf_bridge = skb->nf_bridge)) {
47 /* Return MATCH if the invert flags of the used options are on */
48 if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
49 !(info->invert & XT_PHYSDEV_OP_BRIDGED))
50 return NOMATCH;
51 if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
52 !(info->invert & XT_PHYSDEV_OP_ISIN))
53 return NOMATCH;
54 if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
55 !(info->invert & XT_PHYSDEV_OP_ISOUT))
56 return NOMATCH;
57 if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
58 !(info->invert & XT_PHYSDEV_OP_IN))
59 return NOMATCH;
60 if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
61 !(info->invert & XT_PHYSDEV_OP_OUT))
62 return NOMATCH;
63 return MATCH;
64 }
65
66 /* This only makes sense in the FORWARD and POSTROUTING chains */
67 if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
68 (!!(nf_bridge->mask & BRNF_BRIDGED) ^
69 !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
70 return NOMATCH;
71
72 if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
73 (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
74 (info->bitmask & XT_PHYSDEV_OP_ISOUT &&
75 (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
76 return NOMATCH;
77
78 if (!(info->bitmask & XT_PHYSDEV_OP_IN))
79 goto match_outdev;
80 indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname;
81 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
82 ret |= (((const unsigned int *)indev)[i]
83 ^ ((const unsigned int *)info->physindev)[i])
84 & ((const unsigned int *)info->in_mask)[i];
85 }
86
87 if ((ret == 0) ^ !(info->invert & XT_PHYSDEV_OP_IN))
88 return NOMATCH;
89
90match_outdev:
91 if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
92 return MATCH;
93 outdev = nf_bridge->physoutdev ?
94 nf_bridge->physoutdev->name : nulldevname;
95 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
96 ret |= (((const unsigned int *)outdev)[i]
97 ^ ((const unsigned int *)info->physoutdev)[i])
98 & ((const unsigned int *)info->out_mask)[i];
99 }
100
101 return (ret != 0) ^ !(info->invert & XT_PHYSDEV_OP_OUT);
102}
103
104static int
105checkentry(const char *tablename,
106 const void *ip,
107 const struct xt_match *match,
108 void *matchinfo,
109 unsigned int hook_mask)
110{
111 const struct xt_physdev_info *info = matchinfo;
112
113 if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
114 info->bitmask & ~XT_PHYSDEV_OP_MASK)
115 return 0;
116 if (info->bitmask & XT_PHYSDEV_OP_OUT &&
117 (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
118 info->invert & XT_PHYSDEV_OP_BRIDGED) &&
119 hook_mask & ((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_FORWARD) |
120 (1 << NF_IP_POST_ROUTING))) {
121 printk(KERN_WARNING "physdev match: using --physdev-out in the "
122 "OUTPUT, FORWARD and POSTROUTING chains for non-bridged "
123 "traffic is not supported anymore.\n");
124 if (hook_mask & (1 << NF_IP_LOCAL_OUT))
125 return 0;
126 }
127 return 1;
128}
129
130static struct xt_match xt_physdev_match[] = {
131 {
132 .name = "physdev",
133 .family = AF_INET,
134 .checkentry = checkentry,
135 .match = match,
136 .matchsize = sizeof(struct xt_physdev_info),
137 .me = THIS_MODULE,
138 },
139 {
140 .name = "physdev",
141 .family = AF_INET6,
142 .checkentry = checkentry,
143 .match = match,
144 .matchsize = sizeof(struct xt_physdev_info),
145 .me = THIS_MODULE,
146 },
147};
148
149static int __init xt_physdev_init(void)
150{
151 return xt_register_matches(xt_physdev_match,
152 ARRAY_SIZE(xt_physdev_match));
153}
154
155static void __exit xt_physdev_fini(void)
156{
157 xt_unregister_matches(xt_physdev_match, ARRAY_SIZE(xt_physdev_match));
158}
159
160module_init(xt_physdev_init);
161module_exit(xt_physdev_fini);