// SPDX-License-Identifier: GPL-2.0-only/* 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> */#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/if.h>#include <linux/module.h>#include <linux/skbuff.h>#include <linux/netfilter_bridge.h>#include <linux/netfilter/x_tables.h>#include <uapi/linux/netfilter/xt_physdev.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");MODULE_DESCRIPTION("Xtables: Bridge physical device match");MODULE_ALIAS("ipt_physdev");MODULE_ALIAS("ip6t_physdev");  static boolphysdev_mt(const struct sk_buff *skb, struct xt_action_param *par){	const struct xt_physdev_info *info = par->matchinfo;	const struct net_device *physdev;	unsigned long ret;	const char *indev, *outdev; 	/* 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_info_exists(skb)) {		/* 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 false;		if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&		    !(info->invert & XT_PHYSDEV_OP_ISIN))			return false;		if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&		    !(info->invert & XT_PHYSDEV_OP_ISOUT))			return false;		if ((info->bitmask & XT_PHYSDEV_OP_IN) &&		    !(info->invert & XT_PHYSDEV_OP_IN))			return false;		if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&		    !(info->invert & XT_PHYSDEV_OP_OUT))			return false;		return true;	} 	physdev = nf_bridge_get_physoutdev(skb);	outdev = physdev ? physdev->name : NULL; 	/* This only makes sense in the FORWARD and POSTROUTING chains */	if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&	    (!!outdev ^ !(info->invert & XT_PHYSDEV_OP_BRIDGED)))		return false; 	physdev = nf_bridge_get_physindev(skb, xt_net(par));	indev = physdev ? physdev->name : NULL; 	if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&	    (!indev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||	    (info->bitmask & XT_PHYSDEV_OP_ISOUT &&	    (!outdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))		return false; 	if (!(info->bitmask & XT_PHYSDEV_OP_IN))		goto match_outdev; 	if (indev) {		ret = ifname_compare_aligned(indev, info->physindev,					     info->in_mask); 		if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))			return false;	} match_outdev:	if (!(info->bitmask & XT_PHYSDEV_OP_OUT))		return true; 	if (!outdev)		return false; 	ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask); 	return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));} static int physdev_mt_check_hooks(const struct xt_mtchk_param *par){	const struct xt_physdev_info *info = par->matchinfo; 	if (info->bitmask & (XT_PHYSDEV_OP_OUT | XT_PHYSDEV_OP_ISOUT) &&	    (!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||	     info->invert & XT_PHYSDEV_OP_BRIDGED) &&	    par->hook_mask & (1 << NF_INET_LOCAL_OUT)) {		pr_info_ratelimited("--physdev-out and --physdev-is-out only supported in the FORWARD and POSTROUTING chains with bridged traffic\n");		return -EINVAL;	} 	return 0;} static int physdev_mt_check(const struct xt_mtchk_param *par){	const struct xt_physdev_info *info = par->matchinfo;	static bool brnf_probed __read_mostly; 	if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||	    info->bitmask & ~XT_PHYSDEV_OP_MASK)		return -EINVAL; #define X(memb) strnlen(info->memb, sizeof(info->memb)) >= sizeof(info->memb)	if (info->bitmask & XT_PHYSDEV_OP_IN) {		if (info->physindev[0] == '\0')			return -EINVAL;		if (X(physindev))			return -ENAMETOOLONG;	} 	if (info->bitmask & XT_PHYSDEV_OP_OUT) {		if (info->physoutdev[0] == '\0')			return -EINVAL; 		if (X(physoutdev))			return -ENAMETOOLONG;	} 	if (X(in_mask))		return -ENAMETOOLONG;	if (X(out_mask))		return -ENAMETOOLONG;#undef X 	if (!brnf_probed) {		brnf_probed = true;		request_module("br_netfilter");	} 	return 0;} static struct xt_match physdev_mt_reg[] __read_mostly = {	{		.name		= "physdev",		.family		= NFPROTO_IPV4,		.check_hooks	= physdev_mt_check_hooks,		.checkentry	= physdev_mt_check,		.match		= physdev_mt,		.matchsize	= sizeof(struct xt_physdev_info),		.me		= THIS_MODULE,	},	{		.name		= "physdev",		.family		= NFPROTO_IPV6,		.check_hooks	= physdev_mt_check_hooks,		.checkentry	= physdev_mt_check,		.match		= physdev_mt,		.matchsize	= sizeof(struct xt_physdev_info),		.me		= THIS_MODULE,	},}; static int __init physdev_mt_init(void){	return xt_register_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));} static void __exit physdev_mt_exit(void){	xt_unregister_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));} module_init(physdev_mt_init);module_exit(physdev_mt_exit);