/* 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 intmatch(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 intcheckentry(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);