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- /* Kernel module to match the bridge port in and
- * out device for IP packets coming into contact with a bridge. */
- /* (C) 2001-2003 Bart De Schuymer <bdschuym@pandora.be>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #include <linux/module.h>
- #include <linux/skbuff.h>
- #include <linux/netfilter_bridge.h>
- #include <linux/netfilter/xt_physdev.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter_bridge.h>
- #define MATCH 1
- #define NOMATCH 0
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
- MODULE_DESCRIPTION("iptables bridge physical device match module");
- MODULE_ALIAS("ipt_physdev");
- MODULE_ALIAS("ip6t_physdev");
- static int
- match(const struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- const struct xt_match *match,
- const void *matchinfo,
- int offset,
- unsigned int protoff,
- int *hotdrop)
- {
- int i;
- static const char nulldevname[IFNAMSIZ];
- const struct xt_physdev_info *info = matchinfo;
- unsigned int ret;
- const char *indev, *outdev;
- struct nf_bridge_info *nf_bridge;
- /* Not a bridged IP packet or no info available yet:
- * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if
- * the destination device will be a bridge. */
- if (!(nf_bridge = skb->nf_bridge)) {
- /* Return MATCH if the invert flags of the used options are on */
- if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
- !(info->invert & XT_PHYSDEV_OP_BRIDGED))
- return NOMATCH;
- if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
- !(info->invert & XT_PHYSDEV_OP_ISIN))
- return NOMATCH;
- if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
- !(info->invert & XT_PHYSDEV_OP_ISOUT))
- return NOMATCH;
- if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
- !(info->invert & XT_PHYSDEV_OP_IN))
- return NOMATCH;
- if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
- !(info->invert & XT_PHYSDEV_OP_OUT))
- return NOMATCH;
- return MATCH;
- }
- /* This only makes sense in the FORWARD and POSTROUTING chains */
- if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
- (!!(nf_bridge->mask & BRNF_BRIDGED) ^
- !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
- return NOMATCH;
- if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
- (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
- (info->bitmask & XT_PHYSDEV_OP_ISOUT &&
- (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
- return NOMATCH;
- if (!(info->bitmask & XT_PHYSDEV_OP_IN))
- goto match_outdev;
- indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname;
- for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
- ret |= (((const unsigned int *)indev)[i]
- ^ ((const unsigned int *)info->physindev)[i])
- & ((const unsigned int *)info->in_mask)[i];
- }
- if ((ret == 0) ^ !(info->invert & XT_PHYSDEV_OP_IN))
- return NOMATCH;
- match_outdev:
- if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
- return MATCH;
- outdev = nf_bridge->physoutdev ?
- nf_bridge->physoutdev->name : nulldevname;
- for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) {
- ret |= (((const unsigned int *)outdev)[i]
- ^ ((const unsigned int *)info->physoutdev)[i])
- & ((const unsigned int *)info->out_mask)[i];
- }
- return (ret != 0) ^ !(info->invert & XT_PHYSDEV_OP_OUT);
- }
- static int
- checkentry(const char *tablename,
- const void *ip,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int hook_mask)
- {
- const struct xt_physdev_info *info = matchinfo;
- if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
- info->bitmask & ~XT_PHYSDEV_OP_MASK)
- return 0;
- if (info->bitmask & XT_PHYSDEV_OP_OUT &&
- (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
- info->invert & XT_PHYSDEV_OP_BRIDGED) &&
- hook_mask & ((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_FORWARD) |
- (1 << NF_IP_POST_ROUTING))) {
- printk(KERN_WARNING "physdev match: using --physdev-out in the "
- "OUTPUT, FORWARD and POSTROUTING chains for non-bridged "
- "traffic is not supported anymore.\n");
- if (hook_mask & (1 << NF_IP_LOCAL_OUT))
- return 0;
- }
- return 1;
- }
- static struct xt_match xt_physdev_match[] = {
- {
- .name = "physdev",
- .family = AF_INET,
- .checkentry = checkentry,
- .match = match,
- .matchsize = sizeof(struct xt_physdev_info),
- .me = THIS_MODULE,
- },
- {
- .name = "physdev",
- .family = AF_INET6,
- .checkentry = checkentry,
- .match = match,
- .matchsize = sizeof(struct xt_physdev_info),
- .me = THIS_MODULE,
- },
- };
- static int __init xt_physdev_init(void)
- {
- return xt_register_matches(xt_physdev_match,
- ARRAY_SIZE(xt_physdev_match));
- }
- static void __exit xt_physdev_fini(void)
- {
- xt_unregister_matches(xt_physdev_match, ARRAY_SIZE(xt_physdev_match));
- }
- module_init(xt_physdev_init);
- module_exit(xt_physdev_fini);
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