Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 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> |
Andrew Morton | deb47c6 | 2006-08-15 00:04:56 -0700 | [diff] [blame] | 13 | #include <linux/netfilter_bridge.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 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 | |
| 20 | MODULE_LICENSE("GPL"); |
| 21 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); |
| 22 | MODULE_DESCRIPTION("iptables bridge physical device match module"); |
| 23 | MODULE_ALIAS("ipt_physdev"); |
| 24 | MODULE_ALIAS("ip6t_physdev"); |
| 25 | |
| 26 | static int |
| 27 | match(const struct sk_buff *skb, |
| 28 | const struct net_device *in, |
| 29 | const struct net_device *out, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 30 | const struct xt_match *match, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 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 | |
| 90 | match_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 | |
| 104 | static int |
| 105 | checkentry(const char *tablename, |
| 106 | const void *ip, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 107 | const struct xt_match *match, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 108 | void *matchinfo, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 109 | unsigned int hook_mask) |
| 110 | { |
| 111 | const struct xt_physdev_info *info = matchinfo; |
| 112 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 113 | if (!(info->bitmask & XT_PHYSDEV_OP_MASK) || |
| 114 | info->bitmask & ~XT_PHYSDEV_OP_MASK) |
| 115 | return 0; |
Patrick McHardy | 2bf540b | 2006-12-13 16:54:25 -0800 | [diff] [blame] | 116 | if (info->bitmask & XT_PHYSDEV_OP_OUT && |
Patrick McHardy | 10ea6ac | 2006-07-24 22:54:55 -0700 | [diff] [blame] | 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 " |
Patrick McHardy | 2bf540b | 2006-12-13 16:54:25 -0800 | [diff] [blame] | 123 | "traffic is not supported anymore.\n"); |
| 124 | if (hook_mask & (1 << NF_IP_LOCAL_OUT)) |
| 125 | return 0; |
Patrick McHardy | 10ea6ac | 2006-07-24 22:54:55 -0700 | [diff] [blame] | 126 | } |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 127 | return 1; |
| 128 | } |
| 129 | |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 130 | static 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 | }, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 147 | }; |
| 148 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 149 | static int __init xt_physdev_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 150 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 151 | return xt_register_matches(xt_physdev_match, |
| 152 | ARRAY_SIZE(xt_physdev_match)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 153 | } |
| 154 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 155 | static void __exit xt_physdev_fini(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 156 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 157 | xt_unregister_matches(xt_physdev_match, ARRAY_SIZE(xt_physdev_match)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 158 | } |
| 159 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 160 | module_init(xt_physdev_init); |
| 161 | module_exit(xt_physdev_fini); |