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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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 <net/netfilter/br_netfilter.h>
17
18MODULE_LICENSE("GPL");
19MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
20MODULE_DESCRIPTION("Xtables: Bridge physical device match");
21MODULE_ALIAS("ipt_physdev");
22MODULE_ALIAS("ip6t_physdev");
23
24
25static bool
26physdev_mt(const struct sk_buff *skb, struct xt_action_param *par)
27{
28 const struct xt_physdev_info *info = par->matchinfo;
29 const struct net_device *physdev;
30 unsigned long ret;
31 const char *indev, *outdev;
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 (!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 physdev = nf_bridge_get_physoutdev(skb);
57 outdev = physdev ? physdev->name : NULL;
58
59 /* This only makes sense in the FORWARD and POSTROUTING chains */
60 if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
61 (!!outdev ^ !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
62 return false;
63
64 physdev = nf_bridge_get_physindev(skb);
65 indev = physdev ? physdev->name : NULL;
66
67 if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
68 (!indev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
69 (info->bitmask & XT_PHYSDEV_OP_ISOUT &&
70 (!outdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
71 return false;
72
73 if (!(info->bitmask & XT_PHYSDEV_OP_IN))
74 goto match_outdev;
75
76 if (indev) {
77 ret = ifname_compare_aligned(indev, info->physindev,
78 info->in_mask);
79
80 if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
81 return false;
82 }
83
84match_outdev:
85 if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
86 return true;
87
88 if (!outdev)
89 return false;
90
91 ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask);
92
93 return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));
94}
95
96static int physdev_mt_check(const struct xt_mtchk_param *par)
97{
98 const struct xt_physdev_info *info = par->matchinfo;
99
100 br_netfilter_enable();
101
102 if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
103 info->bitmask & ~XT_PHYSDEV_OP_MASK)
104 return -EINVAL;
105 if (info->bitmask & (XT_PHYSDEV_OP_OUT | XT_PHYSDEV_OP_ISOUT) &&
106 (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
107 info->invert & XT_PHYSDEV_OP_BRIDGED) &&
108 par->hook_mask & ((1 << NF_INET_LOCAL_OUT) |
109 (1 << NF_INET_FORWARD) | (1 << NF_INET_POST_ROUTING))) {
110 pr_info("using --physdev-out and --physdev-is-out are only "
111 "supported in the FORWARD and POSTROUTING chains with "
112 "bridged traffic.\n");
113 if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
114 return -EINVAL;
115 }
116 return 0;
117}
118
119static struct xt_match physdev_mt_reg __read_mostly = {
120 .name = "physdev",
121 .revision = 0,
122 .family = NFPROTO_UNSPEC,
123 .checkentry = physdev_mt_check,
124 .match = physdev_mt,
125 .matchsize = sizeof(struct xt_physdev_info),
126 .me = THIS_MODULE,
127};
128
129static int __init physdev_mt_init(void)
130{
131 return xt_register_match(&physdev_mt_reg);
132}
133
134static void __exit physdev_mt_exit(void)
135{
136 xt_unregister_match(&physdev_mt_reg);
137}
138
139module_init(physdev_mt_init);
140module_exit(physdev_mt_exit);
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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
17MODULE_LICENSE("GPL");
18MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
19MODULE_DESCRIPTION("Xtables: Bridge physical device match");
20MODULE_ALIAS("ipt_physdev");
21MODULE_ALIAS("ip6t_physdev");
22
23
24static bool
25physdev_mt(const struct sk_buff *skb, struct xt_action_param *par)
26{
27 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
28 const struct xt_physdev_info *info = par->matchinfo;
29 unsigned long 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 ret = ifname_compare_aligned(indev, info->physindev, info->in_mask);
72
73 if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
74 return false;
75
76match_outdev:
77 if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
78 return true;
79 outdev = nf_bridge->physoutdev ?
80 nf_bridge->physoutdev->name : nulldevname;
81 ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask);
82
83 return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));
84}
85
86static int physdev_mt_check(const struct xt_mtchk_param *par)
87{
88 const struct xt_physdev_info *info = par->matchinfo;
89
90 if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
91 info->bitmask & ~XT_PHYSDEV_OP_MASK)
92 return -EINVAL;
93 if (info->bitmask & XT_PHYSDEV_OP_OUT &&
94 (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
95 info->invert & XT_PHYSDEV_OP_BRIDGED) &&
96 par->hook_mask & ((1 << NF_INET_LOCAL_OUT) |
97 (1 << NF_INET_FORWARD) | (1 << NF_INET_POST_ROUTING))) {
98 pr_info("using --physdev-out in the OUTPUT, FORWARD and "
99 "POSTROUTING chains for non-bridged traffic is not "
100 "supported anymore.\n");
101 if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
102 return -EINVAL;
103 }
104 return 0;
105}
106
107static struct xt_match physdev_mt_reg __read_mostly = {
108 .name = "physdev",
109 .revision = 0,
110 .family = NFPROTO_UNSPEC,
111 .checkentry = physdev_mt_check,
112 .match = physdev_mt,
113 .matchsize = sizeof(struct xt_physdev_info),
114 .me = THIS_MODULE,
115};
116
117static int __init physdev_mt_init(void)
118{
119 return xt_register_match(&physdev_mt_reg);
120}
121
122static void __exit physdev_mt_exit(void)
123{
124 xt_unregister_match(&physdev_mt_reg);
125}
126
127module_init(physdev_mt_init);
128module_exit(physdev_mt_exit);