net/netfilter/nft_meta.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  * Copyright (c) 2014 Intel Corporation
  * Author: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
  *
  * Development of this code funded by Astaro AG (http://www.astaro.com/)
  */

 #include <linux/kernel.h>
 #include <linux/netlink.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
 #include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/smp.h>
 #include <linux/static_key.h>
 #include <net/dst.h>
 #include <net/sock.h>
 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_core.h>
 #include <net/netfilter/nft_meta.h>
 #include <net/netfilter/nf_tables_offload.h>

 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */

 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);

 void nft_meta_get_eval(const struct nft_expr *expr,
 		       struct nft_regs *regs,
 		       const struct nft_pktinfo *pkt)
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);
 	const struct sk_buff *skb = pkt->skb;
 	const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
 	struct sock *sk;
 	u32 *dest = &regs->data[priv->dreg];

 	switch (priv->key) {
 	case NFT_META_LEN:
 		*dest = skb->len;
 		break;
 	case NFT_META_PROTOCOL:
 		nft_reg_store16(dest, (__force u16)skb->protocol);
 		break;
 	case NFT_META_NFPROTO:
 		nft_reg_store8(dest, nft_pf(pkt));
 		break;
 	case NFT_META_L4PROTO:
 		if (!pkt->tprot_set)
 			goto err;
 		nft_reg_store8(dest, pkt->tprot);
 		break;
 	case NFT_META_PRIORITY:
 		*dest = skb->priority;
 		break;
 	case NFT_META_MARK:
 		*dest = skb->mark;
 		break;
 	case NFT_META_IIF:
 		if (in == NULL)
 			goto err;
 		*dest = in->ifindex;
 		break;
 	case NFT_META_OIF:
 		if (out == NULL)
 			goto err;
 		*dest = out->ifindex;
 		break;
 	case NFT_META_IIFNAME:
 		if (in == NULL)
 			goto err;
 		strncpy((char *)dest, in->name, IFNAMSIZ);
 		break;
 	case NFT_META_OIFNAME:
 		if (out == NULL)
 			goto err;
 		strncpy((char *)dest, out->name, IFNAMSIZ);
 		break;
 	case NFT_META_IIFTYPE:
 		if (in == NULL)
 			goto err;
 		nft_reg_store16(dest, in->type);
 		break;
 	case NFT_META_OIFTYPE:
 		if (out == NULL)
 			goto err;
 		nft_reg_store16(dest, out->type);
 		break;
 	case NFT_META_SKUID:
 		sk = skb_to_full_sk(skb);
 		if (!sk || !sk_fullsock(sk) ||
 		    !net_eq(nft_net(pkt), sock_net(sk)))
 			goto err;

 		read_lock_bh(&sk->sk_callback_lock);
 		if (sk->sk_socket == NULL ||
 		    sk->sk_socket->file == NULL) {
 			read_unlock_bh(&sk->sk_callback_lock);
 			goto err;
 		}

 		*dest =	from_kuid_munged(&init_user_ns,
 				sk->sk_socket->file->f_cred->fsuid);
 		read_unlock_bh(&sk->sk_callback_lock);
 		break;
 	case NFT_META_SKGID:
 		sk = skb_to_full_sk(skb);
 		if (!sk || !sk_fullsock(sk) ||
 		    !net_eq(nft_net(pkt), sock_net(sk)))
 			goto err;

 		read_lock_bh(&sk->sk_callback_lock);
 		if (sk->sk_socket == NULL ||
 		    sk->sk_socket->file == NULL) {
 			read_unlock_bh(&sk->sk_callback_lock);
 			goto err;
 		}
 		*dest =	from_kgid_munged(&init_user_ns,
 				 sk->sk_socket->file->f_cred->fsgid);
 		read_unlock_bh(&sk->sk_callback_lock);
 		break;
 #ifdef CONFIG_IP_ROUTE_CLASSID
 	case NFT_META_RTCLASSID: {
 		const struct dst_entry *dst = skb_dst(skb);

 		if (dst == NULL)
 			goto err;
 		*dest = dst->tclassid;
 		break;
 	}
 #endif
 #ifdef CONFIG_NETWORK_SECMARK
 	case NFT_META_SECMARK:
 		*dest = skb->secmark;
 		break;
 #endif
 	case NFT_META_PKTTYPE:
 		if (skb->pkt_type != PACKET_LOOPBACK) {
 			nft_reg_store8(dest, skb->pkt_type);
 			break;
 		}

 		switch (nft_pf(pkt)) {
 		case NFPROTO_IPV4:
 			if (ipv4_is_multicast(ip_hdr(skb)->daddr))
 				nft_reg_store8(dest, PACKET_MULTICAST);
 			else
 				nft_reg_store8(dest, PACKET_BROADCAST);
 			break;
 		case NFPROTO_IPV6:
 			nft_reg_store8(dest, PACKET_MULTICAST);
 			break;
 		case NFPROTO_NETDEV:
 			switch (skb->protocol) {
 			case htons(ETH_P_IP): {
 				int noff = skb_network_offset(skb);
 				struct iphdr *iph, _iph;

 				iph = skb_header_pointer(skb, noff,
 							 sizeof(_iph), &_iph);
 				if (!iph)
 					goto err;

 				if (ipv4_is_multicast(iph->daddr))
 					nft_reg_store8(dest, PACKET_MULTICAST);
 				else
 					nft_reg_store8(dest, PACKET_BROADCAST);

 				break;
 			}
 			case htons(ETH_P_IPV6):
 				nft_reg_store8(dest, PACKET_MULTICAST);
 				break;
 			default:
 				WARN_ON_ONCE(1);
 				goto err;
 			}
 			break;
 		default:
 			WARN_ON_ONCE(1);
 			goto err;
 		}
 		break;
 	case NFT_META_CPU:
 		*dest = raw_smp_processor_id();
 		break;
 	case NFT_META_IIFGROUP:
 		if (in == NULL)
 			goto err;
 		*dest = in->group;
 		break;
 	case NFT_META_OIFGROUP:
 		if (out == NULL)
 			goto err;
 		*dest = out->group;
 		break;
 #ifdef CONFIG_CGROUP_NET_CLASSID
 	case NFT_META_CGROUP:
 		sk = skb_to_full_sk(skb);
 		if (!sk || !sk_fullsock(sk) ||
 		    !net_eq(nft_net(pkt), sock_net(sk)))
 			goto err;
 		*dest = sock_cgroup_classid(&sk->sk_cgrp_data);
 		break;
 #endif
 	case NFT_META_PRANDOM: {
 		struct rnd_state *state = this_cpu_ptr(&nft_prandom_state);
 		*dest = prandom_u32_state(state);
 		break;
 	}
 #ifdef CONFIG_XFRM
 	case NFT_META_SECPATH:
 		nft_reg_store8(dest, secpath_exists(skb));
 		break;
 #endif
 	case NFT_META_IIFKIND:
 		if (in == NULL || in->rtnl_link_ops == NULL)
 			goto err;
 		strncpy((char *)dest, in->rtnl_link_ops->kind, IFNAMSIZ);
 		break;
 	case NFT_META_OIFKIND:
 		if (out == NULL || out->rtnl_link_ops == NULL)
 			goto err;
 		strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ);
 		break;
 	default:
 		WARN_ON(1);
 		goto err;
 	}
 	return;

 err:
 	regs->verdict.code = NFT_BREAK;
 }
 EXPORT_SYMBOL_GPL(nft_meta_get_eval);

 void nft_meta_set_eval(const struct nft_expr *expr,
 		       struct nft_regs *regs,
 		       const struct nft_pktinfo *pkt)
 {
 	const struct nft_meta *meta = nft_expr_priv(expr);
 	struct sk_buff *skb = pkt->skb;
 	u32 *sreg = &regs->data[meta->sreg];
 	u32 value = *sreg;
 	u8 value8;

 	switch (meta->key) {
 	case NFT_META_MARK:
 		skb->mark = value;
 		break;
 	case NFT_META_PRIORITY:
 		skb->priority = value;
 		break;
 	case NFT_META_PKTTYPE:
 		value8 = nft_reg_load8(sreg);

 		if (skb->pkt_type != value8 &&
 		    skb_pkt_type_ok(value8) &&
 		    skb_pkt_type_ok(skb->pkt_type))
 			skb->pkt_type = value8;
 		break;
 	case NFT_META_NFTRACE:
 		value8 = nft_reg_load8(sreg);

 		skb->nf_trace = !!value8;
 		break;
 #ifdef CONFIG_NETWORK_SECMARK
 	case NFT_META_SECMARK:
 		skb->secmark = value;
 		break;
 #endif
 	default:
 		WARN_ON(1);
 	}
 }
 EXPORT_SYMBOL_GPL(nft_meta_set_eval);

 const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
 	[NFTA_META_DREG]	= { .type = NLA_U32 },
 	[NFTA_META_KEY]		= { .type = NLA_U32 },
 	[NFTA_META_SREG]	= { .type = NLA_U32 },
 };
 EXPORT_SYMBOL_GPL(nft_meta_policy);

 int nft_meta_get_init(const struct nft_ctx *ctx,
 		      const struct nft_expr *expr,
 		      const struct nlattr * const tb[])
 {
 	struct nft_meta *priv = nft_expr_priv(expr);
 	unsigned int len;

 	priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
 	switch (priv->key) {
 	case NFT_META_PROTOCOL:
 	case NFT_META_IIFTYPE:
 	case NFT_META_OIFTYPE:
 		len = sizeof(u16);
 		break;
 	case NFT_META_NFPROTO:
 	case NFT_META_L4PROTO:
 	case NFT_META_LEN:
 	case NFT_META_PRIORITY:
 	case NFT_META_MARK:
 	case NFT_META_IIF:
 	case NFT_META_OIF:
 	case NFT_META_SKUID:
 	case NFT_META_SKGID:
 #ifdef CONFIG_IP_ROUTE_CLASSID
 	case NFT_META_RTCLASSID:
 #endif
 #ifdef CONFIG_NETWORK_SECMARK
 	case NFT_META_SECMARK:
 #endif
 	case NFT_META_PKTTYPE:
 	case NFT_META_CPU:
 	case NFT_META_IIFGROUP:
 	case NFT_META_OIFGROUP:
 #ifdef CONFIG_CGROUP_NET_CLASSID
 	case NFT_META_CGROUP:
 #endif
 		len = sizeof(u32);
 		break;
 	case NFT_META_IIFNAME:
 	case NFT_META_OIFNAME:
 	case NFT_META_IIFKIND:
 	case NFT_META_OIFKIND:
 		len = IFNAMSIZ;
 		break;
 	case NFT_META_PRANDOM:
 		prandom_init_once(&nft_prandom_state);
 		len = sizeof(u32);
 		break;
 #ifdef CONFIG_XFRM
 	case NFT_META_SECPATH:
 		len = sizeof(u8);
 		break;
 #endif
 	default:
 		return -EOPNOTSUPP;
 	}

 	priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
 	return nft_validate_register_store(ctx, priv->dreg, NULL,
 					   NFT_DATA_VALUE, len);
 }
 EXPORT_SYMBOL_GPL(nft_meta_get_init);

 static int nft_meta_get_validate(const struct nft_ctx *ctx,
 				 const struct nft_expr *expr,
 				 const struct nft_data **data)
 {
 #ifdef CONFIG_XFRM
 	const struct nft_meta *priv = nft_expr_priv(expr);
 	unsigned int hooks;

 	if (priv->key != NFT_META_SECPATH)
 		return 0;

 	switch (ctx->family) {
 	case NFPROTO_NETDEV:
 		hooks = 1 << NF_NETDEV_INGRESS;
 		break;
 	case NFPROTO_IPV4:
 	case NFPROTO_IPV6:
 	case NFPROTO_INET:
 		hooks = (1 << NF_INET_PRE_ROUTING) |
 			(1 << NF_INET_LOCAL_IN) |
 			(1 << NF_INET_FORWARD);
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return nft_chain_validate_hooks(ctx->chain, hooks);
 #else
 	return 0;
 #endif
 }

 int nft_meta_set_validate(const struct nft_ctx *ctx,
 			  const struct nft_expr *expr,
 			  const struct nft_data **data)
 {
 	struct nft_meta *priv = nft_expr_priv(expr);
 	unsigned int hooks;

 	if (priv->key != NFT_META_PKTTYPE)
 		return 0;

 	switch (ctx->family) {
 	case NFPROTO_BRIDGE:
 		hooks = 1 << NF_BR_PRE_ROUTING;
 		break;
 	case NFPROTO_NETDEV:
 		hooks = 1 << NF_NETDEV_INGRESS;
 		break;
 	case NFPROTO_IPV4:
 	case NFPROTO_IPV6:
 	case NFPROTO_INET:
 		hooks = 1 << NF_INET_PRE_ROUTING;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return nft_chain_validate_hooks(ctx->chain, hooks);
 }
 EXPORT_SYMBOL_GPL(nft_meta_set_validate);

 int nft_meta_set_init(const struct nft_ctx *ctx,
 		      const struct nft_expr *expr,
 		      const struct nlattr * const tb[])
 {
 	struct nft_meta *priv = nft_expr_priv(expr);
 	unsigned int len;
 	int err;

 	priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
 	switch (priv->key) {
 	case NFT_META_MARK:
 	case NFT_META_PRIORITY:
 #ifdef CONFIG_NETWORK_SECMARK
 	case NFT_META_SECMARK:
 #endif
 		len = sizeof(u32);
 		break;
 	case NFT_META_NFTRACE:
 		len = sizeof(u8);
 		break;
 	case NFT_META_PKTTYPE:
 		len = sizeof(u8);
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	priv->sreg = nft_parse_register(tb[NFTA_META_SREG]);
 	err = nft_validate_register_load(priv->sreg, len);
 	if (err < 0)
 		return err;

 	if (priv->key == NFT_META_NFTRACE)
 		static_branch_inc(&nft_trace_enabled);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(nft_meta_set_init);

 int nft_meta_get_dump(struct sk_buff *skb,
 		      const struct nft_expr *expr)
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);

 	if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
 		goto nla_put_failure;
 	if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg))
 		goto nla_put_failure;
 	return 0;

 nla_put_failure:
 	return -1;
 }
 EXPORT_SYMBOL_GPL(nft_meta_get_dump);

 int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);

 	if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
 		goto nla_put_failure;
 	if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg))
 		goto nla_put_failure;

 	return 0;

 nla_put_failure:
 	return -1;
 }
 EXPORT_SYMBOL_GPL(nft_meta_set_dump);

 void nft_meta_set_destroy(const struct nft_ctx *ctx,
 			  const struct nft_expr *expr)
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);

 	if (priv->key == NFT_META_NFTRACE)
 		static_branch_dec(&nft_trace_enabled);
 }
 EXPORT_SYMBOL_GPL(nft_meta_set_destroy);

 static int nft_meta_get_offload(struct nft_offload_ctx *ctx,
 				struct nft_flow_rule *flow,
 				const struct nft_expr *expr)
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);
 	struct nft_offload_reg *reg = &ctx->regs[priv->dreg];

 	switch (priv->key) {
 	case NFT_META_PROTOCOL:
 		NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, n_proto,
 				  sizeof(__u16), reg);
 		nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
 		break;
 	case NFT_META_L4PROTO:
 		NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
 				  sizeof(__u8), reg);
 		nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return 0;
 }

 static const struct nft_expr_ops nft_meta_get_ops = {
 	.type		= &nft_meta_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_meta)),
 	.eval		= nft_meta_get_eval,
 	.init		= nft_meta_get_init,
 	.dump		= nft_meta_get_dump,
 	.validate	= nft_meta_get_validate,
 	.offload	= nft_meta_get_offload,
 };

 static const struct nft_expr_ops nft_meta_set_ops = {
 	.type		= &nft_meta_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_meta)),
 	.eval		= nft_meta_set_eval,
 	.init		= nft_meta_set_init,
 	.destroy	= nft_meta_set_destroy,
 	.dump		= nft_meta_set_dump,
 	.validate	= nft_meta_set_validate,
 };

 static const struct nft_expr_ops *
 nft_meta_select_ops(const struct nft_ctx *ctx,
 		    const struct nlattr * const tb[])
 {
 	if (tb[NFTA_META_KEY] == NULL)
 		return ERR_PTR(-EINVAL);

 	if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
 		return ERR_PTR(-EINVAL);

 #if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE) && IS_MODULE(CONFIG_NFT_BRIDGE_META)
 	if (ctx->family == NFPROTO_BRIDGE)
 		return ERR_PTR(-EAGAIN);
 #endif
 	if (tb[NFTA_META_DREG])
 		return &nft_meta_get_ops;

 	if (tb[NFTA_META_SREG])
 		return &nft_meta_set_ops;

 	return ERR_PTR(-EINVAL);
 }

 struct nft_expr_type nft_meta_type __read_mostly = {
 	.name		= "meta",
 	.select_ops	= nft_meta_select_ops,
 	.policy		= nft_meta_policy,
 	.maxattr	= NFTA_META_MAX,
 	.owner		= THIS_MODULE,
 };

 #ifdef CONFIG_NETWORK_SECMARK
 struct nft_secmark {
 	u32 secid;
 	char *ctx;
 };

 static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
 	[NFTA_SECMARK_CTX]     = { .type = NLA_STRING, .len = NFT_SECMARK_CTX_MAXLEN },
 };

 static int nft_secmark_compute_secid(struct nft_secmark *priv)
 {
 	u32 tmp_secid = 0;
 	int err;

 	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
 	if (err)
 		return err;

 	if (!tmp_secid)
 		return -ENOENT;

 	err = security_secmark_relabel_packet(tmp_secid);
 	if (err)
 		return err;

 	priv->secid = tmp_secid;
 	return 0;
 }

 static void nft_secmark_obj_eval(struct nft_object *obj, struct nft_regs *regs,
 				 const struct nft_pktinfo *pkt)
 {
 	const struct nft_secmark *priv = nft_obj_data(obj);
 	struct sk_buff *skb = pkt->skb;

 	skb->secmark = priv->secid;
 }

 static int nft_secmark_obj_init(const struct nft_ctx *ctx,
 				const struct nlattr * const tb[],
 				struct nft_object *obj)
 {
 	struct nft_secmark *priv = nft_obj_data(obj);
 	int err;

 	if (tb[NFTA_SECMARK_CTX] == NULL)
 		return -EINVAL;

 	priv->ctx = nla_strdup(tb[NFTA_SECMARK_CTX], GFP_KERNEL);
 	if (!priv->ctx)
 		return -ENOMEM;

 	err = nft_secmark_compute_secid(priv);
 	if (err) {
 		kfree(priv->ctx);
 		return err;
 	}

 	security_secmark_refcount_inc();

 	return 0;
 }

 static int nft_secmark_obj_dump(struct sk_buff *skb, struct nft_object *obj,
 				bool reset)
 {
 	struct nft_secmark *priv = nft_obj_data(obj);
 	int err;

 	if (nla_put_string(skb, NFTA_SECMARK_CTX, priv->ctx))
 		return -1;

 	if (reset) {
 		err = nft_secmark_compute_secid(priv);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static void nft_secmark_obj_destroy(const struct nft_ctx *ctx, struct nft_object *obj)
 {
 	struct nft_secmark *priv = nft_obj_data(obj);

 	security_secmark_refcount_dec();

 	kfree(priv->ctx);
 }

 static const struct nft_object_ops nft_secmark_obj_ops = {
 	.type		= &nft_secmark_obj_type,
 	.size		= sizeof(struct nft_secmark),
 	.init		= nft_secmark_obj_init,
 	.eval		= nft_secmark_obj_eval,
 	.dump		= nft_secmark_obj_dump,
 	.destroy	= nft_secmark_obj_destroy,
 };
 struct nft_object_type nft_secmark_obj_type __read_mostly = {
 	.type		= NFT_OBJECT_SECMARK,
 	.ops		= &nft_secmark_obj_ops,
 	.maxattr	= NFTA_SECMARK_MAX,
 	.policy		= nft_secmark_policy,
 	.owner		= THIS_MODULE,
 };
 #endif /* CONFIG_NETWORK_SECMARK */
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
	* Copyright (c) 2014 Intel Corporation
	* Author: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
	*
	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	*/

	#include <linux/kernel.h>
	#include <linux/netlink.h>
	#include <linux/netfilter.h>
	#include <linux/netfilter/nf_tables.h>
	#include <linux/in.h>
	#include <linux/ip.h>
	#include <linux/ipv6.h>
	#include <linux/smp.h>
	#include <linux/static_key.h>
	#include <net/dst.h>
	#include <net/sock.h>
	#include <net/tcp_states.h> /* for TCP_TIME_WAIT */
	#include <net/netfilter/nf_tables.h>
	#include <net/netfilter/nf_tables_core.h>
	#include <net/netfilter/nft_meta.h>
	#include <net/netfilter/nf_tables_offload.h>

	#include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */

	static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);

	void nft_meta_get_eval(const struct nft_expr *expr,
	struct nft_regs *regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_meta *priv = nft_expr_priv(expr);
	const struct sk_buff *skb = pkt->skb;
	const struct net_device in = nft_in(pkt), out = nft_out(pkt);
	struct sock *sk;
	u32 *dest = &regs->data[priv->dreg];

	switch (priv->key) {
	case NFT_META_LEN:
	*dest = skb->len;
	break;
	case NFT_META_PROTOCOL:
	nft_reg_store16(dest, (__force u16)skb->protocol);
	break;
	case NFT_META_NFPROTO:
	nft_reg_store8(dest, nft_pf(pkt));
	break;
	case NFT_META_L4PROTO:
	if (!pkt->tprot_set)
	goto err;
	nft_reg_store8(dest, pkt->tprot);
	break;
	case NFT_META_PRIORITY:
	*dest = skb->priority;
	break;
	case NFT_META_MARK:
	*dest = skb->mark;
	break;
	case NFT_META_IIF:
	if (in == NULL)
	goto err;
	*dest = in->ifindex;
	break;
	case NFT_META_OIF:
	if (out == NULL)
	goto err;
	*dest = out->ifindex;
	break;
	case NFT_META_IIFNAME:
	if (in == NULL)
	goto err;
	strncpy((char *)dest, in->name, IFNAMSIZ);
	break;
	case NFT_META_OIFNAME:
	if (out == NULL)
	goto err;
	strncpy((char *)dest, out->name, IFNAMSIZ);
	break;
	case NFT_META_IIFTYPE:
	if (in == NULL)
	goto err;
	nft_reg_store16(dest, in->type);
	break;
	case NFT_META_OIFTYPE:
	if (out == NULL)
	goto err;
	nft_reg_store16(dest, out->type);
	break;
	case NFT_META_SKUID:
	sk = skb_to_full_sk(skb);
	if (!sk \|\| !sk_fullsock(sk) \|\|
	!net_eq(nft_net(pkt), sock_net(sk)))
	goto err;

	read_lock_bh(&sk->sk_callback_lock);
	if (sk->sk_socket == NULL \|\|
	sk->sk_socket->file == NULL) {
	read_unlock_bh(&sk->sk_callback_lock);
	goto err;
	}

	*dest = from_kuid_munged(&init_user_ns,
	sk->sk_socket->file->f_cred->fsuid);
	read_unlock_bh(&sk->sk_callback_lock);
	break;
	case NFT_META_SKGID:
	sk = skb_to_full_sk(skb);
	if (!sk \|\| !sk_fullsock(sk) \|\|
	!net_eq(nft_net(pkt), sock_net(sk)))
	goto err;

	read_lock_bh(&sk->sk_callback_lock);
	if (sk->sk_socket == NULL \|\|
	sk->sk_socket->file == NULL) {
	read_unlock_bh(&sk->sk_callback_lock);
	goto err;
	}
	*dest = from_kgid_munged(&init_user_ns,
	sk->sk_socket->file->f_cred->fsgid);
	read_unlock_bh(&sk->sk_callback_lock);
	break;
	#ifdef CONFIG_IP_ROUTE_CLASSID
	case NFT_META_RTCLASSID: {
	const struct dst_entry *dst = skb_dst(skb);

	if (dst == NULL)
	goto err;
	*dest = dst->tclassid;
	break;
	}
	#endif
	#ifdef CONFIG_NETWORK_SECMARK
	case NFT_META_SECMARK:
	*dest = skb->secmark;
	break;
	#endif
	case NFT_META_PKTTYPE:
	if (skb->pkt_type != PACKET_LOOPBACK) {
	nft_reg_store8(dest, skb->pkt_type);
	break;
	}

	switch (nft_pf(pkt)) {
	case NFPROTO_IPV4:
	if (ipv4_is_multicast(ip_hdr(skb)->daddr))
	nft_reg_store8(dest, PACKET_MULTICAST);
	else
	nft_reg_store8(dest, PACKET_BROADCAST);
	break;
	case NFPROTO_IPV6:
	nft_reg_store8(dest, PACKET_MULTICAST);
	break;
	case NFPROTO_NETDEV:
	switch (skb->protocol) {
	case htons(ETH_P_IP): {
	int noff = skb_network_offset(skb);
	struct iphdr *iph, _iph;

	iph = skb_header_pointer(skb, noff,
	sizeof(_iph), &_iph);
	if (!iph)
	goto err;

	if (ipv4_is_multicast(iph->daddr))
	nft_reg_store8(dest, PACKET_MULTICAST);
	else
	nft_reg_store8(dest, PACKET_BROADCAST);

	break;
	}
	case htons(ETH_P_IPV6):
	nft_reg_store8(dest, PACKET_MULTICAST);
	break;
	default:
	WARN_ON_ONCE(1);
	goto err;
	}
	break;
	default:
	WARN_ON_ONCE(1);
	goto err;
	}
	break;
	case NFT_META_CPU:
	*dest = raw_smp_processor_id();
	break;
	case NFT_META_IIFGROUP:
	if (in == NULL)
	goto err;
	*dest = in->group;
	break;
	case NFT_META_OIFGROUP:
	if (out == NULL)
	goto err;
	*dest = out->group;
	break;
	#ifdef CONFIG_CGROUP_NET_CLASSID
	case NFT_META_CGROUP:
	sk = skb_to_full_sk(skb);
	if (!sk \|\| !sk_fullsock(sk) \|\|
	!net_eq(nft_net(pkt), sock_net(sk)))
	goto err;
	*dest = sock_cgroup_classid(&sk->sk_cgrp_data);
	break;
	#endif
	case NFT_META_PRANDOM: {
	struct rnd_state *state = this_cpu_ptr(&nft_prandom_state);
	*dest = prandom_u32_state(state);
	break;
	}
	#ifdef CONFIG_XFRM
	case NFT_META_SECPATH:
	nft_reg_store8(dest, secpath_exists(skb));
	break;
	#endif
	case NFT_META_IIFKIND:
	if (in == NULL \|\| in->rtnl_link_ops == NULL)
	goto err;
	strncpy((char *)dest, in->rtnl_link_ops->kind, IFNAMSIZ);
	break;
	case NFT_META_OIFKIND:
	if (out == NULL \|\| out->rtnl_link_ops == NULL)
	goto err;
	strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ);
	break;
	default:
	WARN_ON(1);
	goto err;
	}
	return;

	err:
	regs->verdict.code = NFT_BREAK;
	}
	EXPORT_SYMBOL_GPL(nft_meta_get_eval);

	void nft_meta_set_eval(const struct nft_expr *expr,
	struct nft_regs *regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_meta *meta = nft_expr_priv(expr);
	struct sk_buff *skb = pkt->skb;
	u32 *sreg = &regs->data[meta->sreg];
	u32 value = *sreg;
	u8 value8;

	switch (meta->key) {
	case NFT_META_MARK:
	skb->mark = value;
	break;
	case NFT_META_PRIORITY:
	skb->priority = value;
	break;
	case NFT_META_PKTTYPE:
	value8 = nft_reg_load8(sreg);

	if (skb->pkt_type != value8 &&
	skb_pkt_type_ok(value8) &&
	skb_pkt_type_ok(skb->pkt_type))
	skb->pkt_type = value8;
	break;
	case NFT_META_NFTRACE:
	value8 = nft_reg_load8(sreg);

	skb->nf_trace = !!value8;
	break;
	#ifdef CONFIG_NETWORK_SECMARK
	case NFT_META_SECMARK:
	skb->secmark = value;
	break;
	#endif
	default:
	WARN_ON(1);
	}
	}
	EXPORT_SYMBOL_GPL(nft_meta_set_eval);

	const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
	[NFTA_META_DREG] = { .type = NLA_U32 },
	[NFTA_META_KEY] = { .type = NLA_U32 },
	[NFTA_META_SREG] = { .type = NLA_U32 },
	};
	EXPORT_SYMBOL_GPL(nft_meta_policy);

	int nft_meta_get_init(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nlattr * const tb[])
	{
	struct nft_meta *priv = nft_expr_priv(expr);
	unsigned int len;

	priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
	switch (priv->key) {
	case NFT_META_PROTOCOL:
	case NFT_META_IIFTYPE:
	case NFT_META_OIFTYPE:
	len = sizeof(u16);
	break;
	case NFT_META_NFPROTO:
	case NFT_META_L4PROTO:
	case NFT_META_LEN:
	case NFT_META_PRIORITY:
	case NFT_META_MARK:
	case NFT_META_IIF:
	case NFT_META_OIF:
	case NFT_META_SKUID:
	case NFT_META_SKGID:
	#ifdef CONFIG_IP_ROUTE_CLASSID
	case NFT_META_RTCLASSID:
	#endif
	#ifdef CONFIG_NETWORK_SECMARK
	case NFT_META_SECMARK:
	#endif
	case NFT_META_PKTTYPE:
	case NFT_META_CPU:
	case NFT_META_IIFGROUP:
	case NFT_META_OIFGROUP:
	#ifdef CONFIG_CGROUP_NET_CLASSID
	case NFT_META_CGROUP:
	#endif
	len = sizeof(u32);
	break;
	case NFT_META_IIFNAME:
	case NFT_META_OIFNAME:
	case NFT_META_IIFKIND:
	case NFT_META_OIFKIND:
	len = IFNAMSIZ;
	break;
	case NFT_META_PRANDOM:
	prandom_init_once(&nft_prandom_state);
	len = sizeof(u32);
	break;
	#ifdef CONFIG_XFRM
	case NFT_META_SECPATH:
	len = sizeof(u8);
	break;
	#endif
	default:
	return -EOPNOTSUPP;
	}

	priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
	return nft_validate_register_store(ctx, priv->dreg, NULL,
	NFT_DATA_VALUE, len);
	}
	EXPORT_SYMBOL_GPL(nft_meta_get_init);

	static int nft_meta_get_validate(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nft_data **data)
	{
	#ifdef CONFIG_XFRM
	const struct nft_meta *priv = nft_expr_priv(expr);
	unsigned int hooks;

	if (priv->key != NFT_META_SECPATH)
	return 0;

	switch (ctx->family) {
	case NFPROTO_NETDEV:
	hooks = 1 << NF_NETDEV_INGRESS;
	break;
	case NFPROTO_IPV4:
	case NFPROTO_IPV6:
	case NFPROTO_INET:
	hooks = (1 << NF_INET_PRE_ROUTING) \|
	(1 << NF_INET_LOCAL_IN) \|
	(1 << NF_INET_FORWARD);
	break;
	default:
	return -EOPNOTSUPP;
	}

	return nft_chain_validate_hooks(ctx->chain, hooks);
	#else
	return 0;
	#endif
	}

	int nft_meta_set_validate(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nft_data **data)
	{
	struct nft_meta *priv = nft_expr_priv(expr);
	unsigned int hooks;

	if (priv->key != NFT_META_PKTTYPE)
	return 0;

	switch (ctx->family) {
	case NFPROTO_BRIDGE:
	hooks = 1 << NF_BR_PRE_ROUTING;
	break;
	case NFPROTO_NETDEV:
	hooks = 1 << NF_NETDEV_INGRESS;
	break;
	case NFPROTO_IPV4:
	case NFPROTO_IPV6:
	case NFPROTO_INET:
	hooks = 1 << NF_INET_PRE_ROUTING;
	break;
	default:
	return -EOPNOTSUPP;
	}

	return nft_chain_validate_hooks(ctx->chain, hooks);
	}
	EXPORT_SYMBOL_GPL(nft_meta_set_validate);

	int nft_meta_set_init(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nlattr * const tb[])
	{
	struct nft_meta *priv = nft_expr_priv(expr);
	unsigned int len;
	int err;

	priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
	switch (priv->key) {
	case NFT_META_MARK:
	case NFT_META_PRIORITY:
	#ifdef CONFIG_NETWORK_SECMARK
	case NFT_META_SECMARK:
	#endif
	len = sizeof(u32);
	break;
	case NFT_META_NFTRACE:
	len = sizeof(u8);
	break;
	case NFT_META_PKTTYPE:
	len = sizeof(u8);
	break;
	default:
	return -EOPNOTSUPP;
	}

	priv->sreg = nft_parse_register(tb[NFTA_META_SREG]);
	err = nft_validate_register_load(priv->sreg, len);
	if (err < 0)
	return err;

	if (priv->key == NFT_META_NFTRACE)
	static_branch_inc(&nft_trace_enabled);

	return 0;
	}
	EXPORT_SYMBOL_GPL(nft_meta_set_init);

	int nft_meta_get_dump(struct sk_buff *skb,
	const struct nft_expr *expr)
	{
	const struct nft_meta *priv = nft_expr_priv(expr);

	if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
	goto nla_put_failure;
	if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg))
	goto nla_put_failure;
	return 0;

	nla_put_failure:
	return -1;
	}
	EXPORT_SYMBOL_GPL(nft_meta_get_dump);

	int nft_meta_set_dump(struct sk_buff skb, const struct nft_expr expr)
	{
	const struct nft_meta *priv = nft_expr_priv(expr);

	if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
	goto nla_put_failure;
	if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg))
	goto nla_put_failure;

	return 0;

	nla_put_failure:
	return -1;
	}
	EXPORT_SYMBOL_GPL(nft_meta_set_dump);

	void nft_meta_set_destroy(const struct nft_ctx *ctx,
	const struct nft_expr *expr)
	{
	const struct nft_meta *priv = nft_expr_priv(expr);

	if (priv->key == NFT_META_NFTRACE)
	static_branch_dec(&nft_trace_enabled);
	}
	EXPORT_SYMBOL_GPL(nft_meta_set_destroy);

	static int nft_meta_get_offload(struct nft_offload_ctx *ctx,
	struct nft_flow_rule *flow,
	const struct nft_expr *expr)
	{
	const struct nft_meta *priv = nft_expr_priv(expr);
	struct nft_offload_reg *reg = &ctx->regs[priv->dreg];

	switch (priv->key) {
	case NFT_META_PROTOCOL:
	NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, n_proto,
	sizeof(__u16), reg);
	nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
	break;
	case NFT_META_L4PROTO:
	NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
	sizeof(__u8), reg);
	nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
	break;
	default:
	return -EOPNOTSUPP;
	}

	return 0;
	}

	static const struct nft_expr_ops nft_meta_get_ops = {
	.type = &nft_meta_type,
	.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
	.eval = nft_meta_get_eval,
	.init = nft_meta_get_init,
	.dump = nft_meta_get_dump,
	.validate = nft_meta_get_validate,
	.offload = nft_meta_get_offload,
	};

	static const struct nft_expr_ops nft_meta_set_ops = {
	.type = &nft_meta_type,
	.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
	.eval = nft_meta_set_eval,
	.init = nft_meta_set_init,
	.destroy = nft_meta_set_destroy,
	.dump = nft_meta_set_dump,
	.validate = nft_meta_set_validate,
	};

	static const struct nft_expr_ops *
	nft_meta_select_ops(const struct nft_ctx *ctx,
	const struct nlattr * const tb[])
	{
	if (tb[NFTA_META_KEY] == NULL)
	return ERR_PTR(-EINVAL);

	if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
	return ERR_PTR(-EINVAL);

	#if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE) && IS_MODULE(CONFIG_NFT_BRIDGE_META)
	if (ctx->family == NFPROTO_BRIDGE)
	return ERR_PTR(-EAGAIN);
	#endif
	if (tb[NFTA_META_DREG])
	return &nft_meta_get_ops;

	if (tb[NFTA_META_SREG])
	return &nft_meta_set_ops;

	return ERR_PTR(-EINVAL);
	}

	struct nft_expr_type nft_meta_type __read_mostly = {
	.name = "meta",
	.select_ops = nft_meta_select_ops,
	.policy = nft_meta_policy,
	.maxattr = NFTA_META_MAX,
	.owner = THIS_MODULE,
	};

	#ifdef CONFIG_NETWORK_SECMARK
	struct nft_secmark {
	u32 secid;
	char *ctx;
	};

	static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
	[NFTA_SECMARK_CTX] = { .type = NLA_STRING, .len = NFT_SECMARK_CTX_MAXLEN },
	};

	static int nft_secmark_compute_secid(struct nft_secmark *priv)
	{
	u32 tmp_secid = 0;
	int err;

	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
	if (err)
	return err;

	if (!tmp_secid)
	return -ENOENT;

	err = security_secmark_relabel_packet(tmp_secid);
	if (err)
	return err;

	priv->secid = tmp_secid;
	return 0;
	}

	static void nft_secmark_obj_eval(struct nft_object obj, struct nft_regs regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_secmark *priv = nft_obj_data(obj);
	struct sk_buff *skb = pkt->skb;

	skb->secmark = priv->secid;
	}

	static int nft_secmark_obj_init(const struct nft_ctx *ctx,
	const struct nlattr * const tb[],
	struct nft_object *obj)
	{
	struct nft_secmark *priv = nft_obj_data(obj);
	int err;

	if (tb[NFTA_SECMARK_CTX] == NULL)
	return -EINVAL;

	priv->ctx = nla_strdup(tb[NFTA_SECMARK_CTX], GFP_KERNEL);
	if (!priv->ctx)
	return -ENOMEM;

	err = nft_secmark_compute_secid(priv);
	if (err) {
	kfree(priv->ctx);
	return err;
	}

	security_secmark_refcount_inc();

	return 0;
	}

	static int nft_secmark_obj_dump(struct sk_buff skb, struct nft_object obj,
	bool reset)
	{
	struct nft_secmark *priv = nft_obj_data(obj);
	int err;

	if (nla_put_string(skb, NFTA_SECMARK_CTX, priv->ctx))
	return -1;

	if (reset) {
	err = nft_secmark_compute_secid(priv);
	if (err)
	return err;
	}

	return 0;
	}

	static void nft_secmark_obj_destroy(const struct nft_ctx ctx, struct nft_object obj)
	{
	struct nft_secmark *priv = nft_obj_data(obj);

	security_secmark_refcount_dec();

	kfree(priv->ctx);
	}

	static const struct nft_object_ops nft_secmark_obj_ops = {
	.type = &nft_secmark_obj_type,
	.size = sizeof(struct nft_secmark),
	.init = nft_secmark_obj_init,
	.eval = nft_secmark_obj_eval,
	.dump = nft_secmark_obj_dump,
	.destroy = nft_secmark_obj_destroy,
	};
	struct nft_object_type nft_secmark_obj_type __read_mostly = {
	.type = NFT_OBJECT_SECMARK,
	.ops = &nft_secmark_obj_ops,
	.maxattr = NFTA_SECMARK_MAX,
	.policy = nft_secmark_policy,
	.owner = THIS_MODULE,
	};
	#endif /* CONFIG_NETWORK_SECMARK */