net/netfilter/nf_tables_offload.c - third_party/kernel - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/netfilter.h>
 #include <net/flow_offload.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_offload.h>
 #include <net/pkt_cls.h>

 static struct nft_flow_rule *nft_flow_rule_alloc(int num_actions)
 {
 	struct nft_flow_rule *flow;

 	flow = kzalloc(sizeof(struct nft_flow_rule), GFP_KERNEL);
 	if (!flow)
 		return NULL;

 	flow->rule = flow_rule_alloc(num_actions);
 	if (!flow->rule) {
 		kfree(flow);
 		return NULL;
 	}

 	flow->rule->match.dissector	= &flow->match.dissector;
 	flow->rule->match.mask		= &flow->match.mask;
 	flow->rule->match.key		= &flow->match.key;

 	return flow;
 }

 void nft_flow_rule_set_addr_type(struct nft_flow_rule *flow,
 				 enum flow_dissector_key_id addr_type)
 {
 	struct nft_flow_match *match = &flow->match;
 	struct nft_flow_key *mask = &match->mask;
 	struct nft_flow_key *key = &match->key;

 	if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_CONTROL))
 		return;

 	key->control.addr_type = addr_type;
 	mask->control.addr_type = 0xffff;
 	match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_CONTROL);
 	match->dissector.offset[FLOW_DISSECTOR_KEY_CONTROL] =
 		offsetof(struct nft_flow_key, control);
 }

 struct nft_flow_rule *nft_flow_rule_create(struct net *net,
 					   const struct nft_rule *rule)
 {
 	struct nft_offload_ctx *ctx;
 	struct nft_flow_rule *flow;
 	int num_actions = 0, err;
 	struct nft_expr *expr;

 	expr = nft_expr_first(rule);
 	while (nft_expr_more(rule, expr)) {
 		if (expr->ops->offload_flags & NFT_OFFLOAD_F_ACTION)
 			num_actions++;

 		expr = nft_expr_next(expr);
 	}

 	if (num_actions == 0)
 		return ERR_PTR(-EOPNOTSUPP);

 	flow = nft_flow_rule_alloc(num_actions);
 	if (!flow)
 		return ERR_PTR(-ENOMEM);

 	expr = nft_expr_first(rule);

 	ctx = kzalloc(sizeof(struct nft_offload_ctx), GFP_KERNEL);
 	if (!ctx) {
 		err = -ENOMEM;
 		goto err_out;
 	}
 	ctx->net = net;
 	ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;

 	while (nft_expr_more(rule, expr)) {
 		if (!expr->ops->offload) {
 			err = -EOPNOTSUPP;
 			goto err_out;
 		}
 		err = expr->ops->offload(ctx, flow, expr);
 		if (err < 0)
 			goto err_out;

 		expr = nft_expr_next(expr);
 	}
 	flow->proto = ctx->dep.l3num;
 	kfree(ctx);

 	return flow;
 err_out:
 	kfree(ctx);
 	nft_flow_rule_destroy(flow);

 	return ERR_PTR(err);
 }

 void nft_flow_rule_destroy(struct nft_flow_rule *flow)
 {
 	struct flow_action_entry *entry;
 	int i;

 	flow_action_for_each(i, entry, &flow->rule->action) {
 		switch (entry->id) {
 		case FLOW_ACTION_REDIRECT:
 		case FLOW_ACTION_MIRRED:
 			dev_put(entry->dev);
 			break;
 		default:
 			break;
 		}
 	}
 	kfree(flow->rule);
 	kfree(flow);
 }

 void nft_offload_set_dependency(struct nft_offload_ctx *ctx,
 				enum nft_offload_dep_type type)
 {
 	ctx->dep.type = type;
 }

 void nft_offload_update_dependency(struct nft_offload_ctx *ctx,
 				   const void *data, u32 len)
 {
 	switch (ctx->dep.type) {
 	case NFT_OFFLOAD_DEP_NETWORK:
 		WARN_ON(len != sizeof(__u16));
 		memcpy(&ctx->dep.l3num, data, sizeof(__u16));
 		break;
 	case NFT_OFFLOAD_DEP_TRANSPORT:
 		WARN_ON(len != sizeof(__u8));
 		memcpy(&ctx->dep.protonum, data, sizeof(__u8));
 		break;
 	default:
 		break;
 	}
 	ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;
 }

 static void nft_flow_offload_common_init(struct flow_cls_common_offload *common,
 					 __be16 proto, int priority,
 					 struct netlink_ext_ack *extack)
 {
 	common->protocol = proto;
 	common->prio = priority;
 	common->extack = extack;
 }

 static int nft_setup_cb_call(struct nft_base_chain *basechain,
 			     enum tc_setup_type type, void *type_data)
 {
 	struct flow_block_cb *block_cb;
 	int err;

 	list_for_each_entry(block_cb, &basechain->flow_block.cb_list, list) {
 		err = block_cb->cb(type, type_data, block_cb->cb_priv);
 		if (err < 0)
 			return err;
 	}
 	return 0;
 }

 int nft_chain_offload_priority(struct nft_base_chain *basechain)
 {
 	if (basechain->ops.priority <= 0 ||
 	    basechain->ops.priority > USHRT_MAX)
 		return -1;

 	return 0;
 }

 static int nft_flow_offload_rule(struct nft_chain *chain,
 				 struct nft_rule *rule,
 				 struct nft_flow_rule *flow,
 				 enum flow_cls_command command)
 {
 	struct flow_cls_offload cls_flow = {};
 	struct nft_base_chain *basechain;
 	struct netlink_ext_ack extack;
 	__be16 proto = ETH_P_ALL;

 	if (!nft_is_base_chain(chain))
 		return -EOPNOTSUPP;

 	basechain = nft_base_chain(chain);

 	if (flow)
 		proto = flow->proto;

 	nft_flow_offload_common_init(&cls_flow.common, proto,
 				     basechain->ops.priority, &extack);
 	cls_flow.command = command;
 	cls_flow.cookie = (unsigned long) rule;
 	if (flow)
 		cls_flow.rule = flow->rule;

 	return nft_setup_cb_call(basechain, TC_SETUP_CLSFLOWER, &cls_flow);
 }

 static int nft_flow_offload_bind(struct flow_block_offload *bo,
 				 struct nft_base_chain *basechain)
 {
 	list_splice(&bo->cb_list, &basechain->flow_block.cb_list);
 	return 0;
 }

 static int nft_flow_offload_unbind(struct flow_block_offload *bo,
 				   struct nft_base_chain *basechain)
 {
 	struct flow_block_cb *block_cb, *next;

 	list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
 		list_del(&block_cb->list);
 		flow_block_cb_free(block_cb);
 	}

 	return 0;
 }

 static int nft_block_setup(struct nft_base_chain *basechain,
 			   struct flow_block_offload *bo,
 			   enum flow_block_command cmd)
 {
 	int err;

 	switch (cmd) {
 	case FLOW_BLOCK_BIND:
 		err = nft_flow_offload_bind(bo, basechain);
 		break;
 	case FLOW_BLOCK_UNBIND:
 		err = nft_flow_offload_unbind(bo, basechain);
 		break;
 	default:
 		WARN_ON_ONCE(1);
 		err = -EOPNOTSUPP;
 	}

 	return err;
 }

 static int nft_block_offload_cmd(struct nft_base_chain *chain,
 				 struct net_device *dev,
 				 enum flow_block_command cmd)
 {
 	struct netlink_ext_ack extack = {};
 	struct flow_block_offload bo = {};
 	int err;

 	bo.net = dev_net(dev);
 	bo.block = &chain->flow_block;
 	bo.command = cmd;
 	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 	bo.extack = &extack;
 	INIT_LIST_HEAD(&bo.cb_list);

 	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 	if (err < 0)
 		return err;

 	return nft_block_setup(chain, &bo, cmd);
 }

 static void nft_indr_block_ing_cmd(struct net_device *dev,
 				   struct nft_base_chain *chain,
 				   flow_indr_block_bind_cb_t *cb,
 				   void *cb_priv,
 				   enum flow_block_command cmd)
 {
 	struct netlink_ext_ack extack = {};
 	struct flow_block_offload bo = {};

 	if (!chain)
 		return;

 	bo.net = dev_net(dev);
 	bo.block = &chain->flow_block;
 	bo.command = cmd;
 	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 	bo.extack = &extack;
 	INIT_LIST_HEAD(&bo.cb_list);

 	cb(dev, cb_priv, TC_SETUP_BLOCK, &bo);

 	nft_block_setup(chain, &bo, cmd);
 }

 static int nft_indr_block_offload_cmd(struct nft_base_chain *chain,
 				      struct net_device *dev,
 				      enum flow_block_command cmd)
 {
 	struct flow_block_offload bo = {};
 	struct netlink_ext_ack extack = {};

 	bo.net = dev_net(dev);
 	bo.block = &chain->flow_block;
 	bo.command = cmd;
 	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 	bo.extack = &extack;
 	INIT_LIST_HEAD(&bo.cb_list);

 	flow_indr_block_call(dev, &bo, cmd);

 	if (list_empty(&bo.cb_list))
 		return -EOPNOTSUPP;

 	return nft_block_setup(chain, &bo, cmd);
 }

 #define FLOW_SETUP_BLOCK TC_SETUP_BLOCK

 static int nft_flow_offload_chain(struct nft_chain *chain,
 				  u8 *ppolicy,
 				  enum flow_block_command cmd)
 {
 	struct nft_base_chain *basechain;
 	struct net_device *dev;
 	u8 policy;

 	if (!nft_is_base_chain(chain))
 		return -EOPNOTSUPP;

 	basechain = nft_base_chain(chain);
 	dev = basechain->ops.dev;
 	if (!dev)
 		return -EOPNOTSUPP;

 	policy = ppolicy ? *ppolicy : basechain->policy;

 	/* Only default policy to accept is supported for now. */
 	if (cmd == FLOW_BLOCK_BIND && policy == NF_DROP)
 		return -EOPNOTSUPP;

 	if (dev->netdev_ops->ndo_setup_tc)
 		return nft_block_offload_cmd(basechain, dev, cmd);
 	else
 		return nft_indr_block_offload_cmd(basechain, dev, cmd);
 }

 int nft_flow_rule_offload_commit(struct net *net)
 {
 	struct nft_trans *trans;
 	int err = 0;
 	u8 policy;

 	list_for_each_entry(trans, &net->nft.commit_list, list) {
 		if (trans->ctx.family != NFPROTO_NETDEV)
 			continue;

 		switch (trans->msg_type) {
 		case NFT_MSG_NEWCHAIN:
 			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD) ||
 			    nft_trans_chain_update(trans))
 				continue;

 			policy = nft_trans_chain_policy(trans);
 			err = nft_flow_offload_chain(trans->ctx.chain, &policy,
 						     FLOW_BLOCK_BIND);
 			break;
 		case NFT_MSG_DELCHAIN:
 			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 				continue;

 			policy = nft_trans_chain_policy(trans);
 			err = nft_flow_offload_chain(trans->ctx.chain, &policy,
 						     FLOW_BLOCK_UNBIND);
 			break;
 		case NFT_MSG_NEWRULE:
 			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 				continue;

 			if (trans->ctx.flags & NLM_F_REPLACE ||
 			    !(trans->ctx.flags & NLM_F_APPEND)) {
 				err = -EOPNOTSUPP;
 				break;
 			}
 			err = nft_flow_offload_rule(trans->ctx.chain,
 						    nft_trans_rule(trans),
 						    nft_trans_flow_rule(trans),
 						    FLOW_CLS_REPLACE);
 			break;
 		case NFT_MSG_DELRULE:
 			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 				continue;

 			err = nft_flow_offload_rule(trans->ctx.chain,
 						    nft_trans_rule(trans),
 						    nft_trans_flow_rule(trans),
 						    FLOW_CLS_DESTROY);
 			break;
 		}

 		if (err)
 			break;
 	}

 	list_for_each_entry(trans, &net->nft.commit_list, list) {
 		if (trans->ctx.family != NFPROTO_NETDEV)
 			continue;

 		switch (trans->msg_type) {
 		case NFT_MSG_NEWRULE:
 			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 				continue;

 			nft_flow_rule_destroy(nft_trans_flow_rule(trans));
 			break;
 		default:
 			break;
 		}
 	}

 	return err;
 }

 static struct nft_chain *__nft_offload_get_chain(struct net_device *dev)
 {
 	struct nft_base_chain *basechain;
 	struct net *net = dev_net(dev);
 	const struct nft_table *table;
 	struct nft_chain *chain;

 	list_for_each_entry(table, &net->nft.tables, list) {
 		if (table->family != NFPROTO_NETDEV)
 			continue;

 		list_for_each_entry(chain, &table->chains, list) {
 			if (!nft_is_base_chain(chain) ||
 			    !(chain->flags & NFT_CHAIN_HW_OFFLOAD))
 				continue;

 			basechain = nft_base_chain(chain);
 			if (strncmp(basechain->dev_name, dev->name, IFNAMSIZ))
 				continue;

 			return chain;
 		}
 	}

 	return NULL;
 }

 static void nft_indr_block_cb(struct net_device *dev,
 			      flow_indr_block_bind_cb_t *cb, void *cb_priv,
 			      enum flow_block_command cmd)
 {
 	struct net *net = dev_net(dev);
 	struct nft_chain *chain;

 	mutex_lock(&net->nft.commit_mutex);
 	chain = __nft_offload_get_chain(dev);
 	if (chain && chain->flags & NFT_CHAIN_HW_OFFLOAD) {
 		struct nft_base_chain *basechain;

 		basechain = nft_base_chain(chain);
 		nft_indr_block_ing_cmd(dev, basechain, cb, cb_priv, cmd);
 	}
 	mutex_unlock(&net->nft.commit_mutex);
 }

 static void nft_offload_chain_clean(struct nft_chain *chain)
 {
 	struct nft_rule *rule;

 	list_for_each_entry(rule, &chain->rules, list) {
 		nft_flow_offload_rule(chain, rule,
 				      NULL, FLOW_CLS_DESTROY);
 	}

 	nft_flow_offload_chain(chain, NULL, FLOW_BLOCK_UNBIND);
 }

 static int nft_offload_netdev_event(struct notifier_block *this,
 				    unsigned long event, void *ptr)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct net *net = dev_net(dev);
 	struct nft_chain *chain;

 	if (event != NETDEV_UNREGISTER)
 		return NOTIFY_DONE;

 	mutex_lock(&net->nft.commit_mutex);
 	chain = __nft_offload_get_chain(dev);
 	if (chain)
 		nft_offload_chain_clean(chain);
 	mutex_unlock(&net->nft.commit_mutex);

 	return NOTIFY_DONE;
 }

 static struct flow_indr_block_entry block_ing_entry = {
 	.cb	= nft_indr_block_cb,
 	.list	= LIST_HEAD_INIT(block_ing_entry.list),
 };

 static struct notifier_block nft_offload_netdev_notifier = {
 	.notifier_call	= nft_offload_netdev_event,
 };

 int nft_offload_init(void)
 {
 	int err;

 	err = register_netdevice_notifier(&nft_offload_netdev_notifier);
 	if (err < 0)
 		return err;

 	flow_indr_add_block_cb(&block_ing_entry);

 	return 0;
 }

 void nft_offload_exit(void)
 {
 	flow_indr_del_block_cb(&block_ing_entry);
 	unregister_netdevice_notifier(&nft_offload_netdev_notifier);
 }
	/* SPDX-License-Identifier: GPL-2.0 */
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/netfilter.h>
	#include <net/flow_offload.h>
	#include <net/netfilter/nf_tables.h>
	#include <net/netfilter/nf_tables_offload.h>
	#include <net/pkt_cls.h>

	static struct nft_flow_rule *nft_flow_rule_alloc(int num_actions)
	{
	struct nft_flow_rule *flow;

	flow = kzalloc(sizeof(struct nft_flow_rule), GFP_KERNEL);
	if (!flow)
	return NULL;

	flow->rule = flow_rule_alloc(num_actions);
	if (!flow->rule) {
	kfree(flow);
	return NULL;
	}

	flow->rule->match.dissector = &flow->match.dissector;
	flow->rule->match.mask = &flow->match.mask;
	flow->rule->match.key = &flow->match.key;

	return flow;
	}

	void nft_flow_rule_set_addr_type(struct nft_flow_rule *flow,
	enum flow_dissector_key_id addr_type)
	{
	struct nft_flow_match *match = &flow->match;
	struct nft_flow_key *mask = &match->mask;
	struct nft_flow_key *key = &match->key;

	if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_CONTROL))
	return;

	key->control.addr_type = addr_type;
	mask->control.addr_type = 0xffff;
	match->dissector.used_keys \|= BIT(FLOW_DISSECTOR_KEY_CONTROL);
	match->dissector.offset[FLOW_DISSECTOR_KEY_CONTROL] =
	offsetof(struct nft_flow_key, control);
	}

	struct nft_flow_rule nft_flow_rule_create(struct net net,
	const struct nft_rule *rule)
	{
	struct nft_offload_ctx *ctx;
	struct nft_flow_rule *flow;
	int num_actions = 0, err;
	struct nft_expr *expr;

	expr = nft_expr_first(rule);
	while (nft_expr_more(rule, expr)) {
	if (expr->ops->offload_flags & NFT_OFFLOAD_F_ACTION)
	num_actions++;

	expr = nft_expr_next(expr);
	}

	if (num_actions == 0)
	return ERR_PTR(-EOPNOTSUPP);

	flow = nft_flow_rule_alloc(num_actions);
	if (!flow)
	return ERR_PTR(-ENOMEM);

	expr = nft_expr_first(rule);

	ctx = kzalloc(sizeof(struct nft_offload_ctx), GFP_KERNEL);
	if (!ctx) {
	err = -ENOMEM;
	goto err_out;
	}
	ctx->net = net;
	ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;

	while (nft_expr_more(rule, expr)) {
	if (!expr->ops->offload) {
	err = -EOPNOTSUPP;
	goto err_out;
	}
	err = expr->ops->offload(ctx, flow, expr);
	if (err < 0)
	goto err_out;

	expr = nft_expr_next(expr);
	}
	flow->proto = ctx->dep.l3num;
	kfree(ctx);

	return flow;
	err_out:
	kfree(ctx);
	nft_flow_rule_destroy(flow);

	return ERR_PTR(err);
	}

	void nft_flow_rule_destroy(struct nft_flow_rule *flow)
	{
	struct flow_action_entry *entry;
	int i;

	flow_action_for_each(i, entry, &flow->rule->action) {
	switch (entry->id) {
	case FLOW_ACTION_REDIRECT:
	case FLOW_ACTION_MIRRED:
	dev_put(entry->dev);
	break;
	default:
	break;
	}
	}
	kfree(flow->rule);
	kfree(flow);
	}

	void nft_offload_set_dependency(struct nft_offload_ctx *ctx,
	enum nft_offload_dep_type type)
	{
	ctx->dep.type = type;
	}

	void nft_offload_update_dependency(struct nft_offload_ctx *ctx,
	const void *data, u32 len)
	{
	switch (ctx->dep.type) {
	case NFT_OFFLOAD_DEP_NETWORK:
	WARN_ON(len != sizeof(__u16));
	memcpy(&ctx->dep.l3num, data, sizeof(__u16));
	break;
	case NFT_OFFLOAD_DEP_TRANSPORT:
	WARN_ON(len != sizeof(__u8));
	memcpy(&ctx->dep.protonum, data, sizeof(__u8));
	break;
	default:
	break;
	}
	ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;
	}

	static void nft_flow_offload_common_init(struct flow_cls_common_offload *common,
	__be16 proto, int priority,
	struct netlink_ext_ack *extack)
	{
	common->protocol = proto;
	common->prio = priority;
	common->extack = extack;
	}

	static int nft_setup_cb_call(struct nft_base_chain *basechain,
	enum tc_setup_type type, void *type_data)
	{
	struct flow_block_cb *block_cb;
	int err;

	list_for_each_entry(block_cb, &basechain->flow_block.cb_list, list) {
	err = block_cb->cb(type, type_data, block_cb->cb_priv);
	if (err < 0)
	return err;
	}
	return 0;
	}

	int nft_chain_offload_priority(struct nft_base_chain *basechain)
	{
	if (basechain->ops.priority <= 0 \|\|
	basechain->ops.priority > USHRT_MAX)
	return -1;

	return 0;
	}

	static int nft_flow_offload_rule(struct nft_chain *chain,
	struct nft_rule *rule,
	struct nft_flow_rule *flow,
	enum flow_cls_command command)
	{
	struct flow_cls_offload cls_flow = {};
	struct nft_base_chain *basechain;
	struct netlink_ext_ack extack;
	__be16 proto = ETH_P_ALL;

	if (!nft_is_base_chain(chain))
	return -EOPNOTSUPP;

	basechain = nft_base_chain(chain);

	if (flow)
	proto = flow->proto;

	nft_flow_offload_common_init(&cls_flow.common, proto,
	basechain->ops.priority, &extack);
	cls_flow.command = command;
	cls_flow.cookie = (unsigned long) rule;
	if (flow)
	cls_flow.rule = flow->rule;

	return nft_setup_cb_call(basechain, TC_SETUP_CLSFLOWER, &cls_flow);
	}

	static int nft_flow_offload_bind(struct flow_block_offload *bo,
	struct nft_base_chain *basechain)
	{
	list_splice(&bo->cb_list, &basechain->flow_block.cb_list);
	return 0;
	}

	static int nft_flow_offload_unbind(struct flow_block_offload *bo,
	struct nft_base_chain *basechain)
	{
	struct flow_block_cb block_cb, next;

	list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
	list_del(&block_cb->list);
	flow_block_cb_free(block_cb);
	}

	return 0;
	}

	static int nft_block_setup(struct nft_base_chain *basechain,
	struct flow_block_offload *bo,
	enum flow_block_command cmd)
	{
	int err;

	switch (cmd) {
	case FLOW_BLOCK_BIND:
	err = nft_flow_offload_bind(bo, basechain);
	break;
	case FLOW_BLOCK_UNBIND:
	err = nft_flow_offload_unbind(bo, basechain);
	break;
	default:
	WARN_ON_ONCE(1);
	err = -EOPNOTSUPP;
	}

	return err;
	}

	static int nft_block_offload_cmd(struct nft_base_chain *chain,
	struct net_device *dev,
	enum flow_block_command cmd)
	{
	struct netlink_ext_ack extack = {};
	struct flow_block_offload bo = {};
	int err;

	bo.net = dev_net(dev);
	bo.block = &chain->flow_block;
	bo.command = cmd;
	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
	bo.extack = &extack;
	INIT_LIST_HEAD(&bo.cb_list);

	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
	if (err < 0)
	return err;

	return nft_block_setup(chain, &bo, cmd);
	}

	static void nft_indr_block_ing_cmd(struct net_device *dev,
	struct nft_base_chain *chain,
	flow_indr_block_bind_cb_t *cb,
	void *cb_priv,
	enum flow_block_command cmd)
	{
	struct netlink_ext_ack extack = {};
	struct flow_block_offload bo = {};

	if (!chain)
	return;

	bo.net = dev_net(dev);
	bo.block = &chain->flow_block;
	bo.command = cmd;
	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
	bo.extack = &extack;
	INIT_LIST_HEAD(&bo.cb_list);

	cb(dev, cb_priv, TC_SETUP_BLOCK, &bo);

	nft_block_setup(chain, &bo, cmd);
	}

	static int nft_indr_block_offload_cmd(struct nft_base_chain *chain,
	struct net_device *dev,
	enum flow_block_command cmd)
	{
	struct flow_block_offload bo = {};
	struct netlink_ext_ack extack = {};

	bo.net = dev_net(dev);
	bo.block = &chain->flow_block;
	bo.command = cmd;
	bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
	bo.extack = &extack;
	INIT_LIST_HEAD(&bo.cb_list);

	flow_indr_block_call(dev, &bo, cmd);

	if (list_empty(&bo.cb_list))
	return -EOPNOTSUPP;

	return nft_block_setup(chain, &bo, cmd);
	}

	#define FLOW_SETUP_BLOCK TC_SETUP_BLOCK

	static int nft_flow_offload_chain(struct nft_chain *chain,
	u8 *ppolicy,
	enum flow_block_command cmd)
	{
	struct nft_base_chain *basechain;
	struct net_device *dev;
	u8 policy;

	if (!nft_is_base_chain(chain))
	return -EOPNOTSUPP;

	basechain = nft_base_chain(chain);
	dev = basechain->ops.dev;
	if (!dev)
	return -EOPNOTSUPP;

	policy = ppolicy ? *ppolicy : basechain->policy;

	/* Only default policy to accept is supported for now. */
	if (cmd == FLOW_BLOCK_BIND && policy == NF_DROP)
	return -EOPNOTSUPP;

	if (dev->netdev_ops->ndo_setup_tc)
	return nft_block_offload_cmd(basechain, dev, cmd);
	else
	return nft_indr_block_offload_cmd(basechain, dev, cmd);
	}

	int nft_flow_rule_offload_commit(struct net *net)
	{
	struct nft_trans *trans;
	int err = 0;
	u8 policy;

	list_for_each_entry(trans, &net->nft.commit_list, list) {
	if (trans->ctx.family != NFPROTO_NETDEV)
	continue;

	switch (trans->msg_type) {
	case NFT_MSG_NEWCHAIN:
	if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD) \|\|
	nft_trans_chain_update(trans))
	continue;

	policy = nft_trans_chain_policy(trans);
	err = nft_flow_offload_chain(trans->ctx.chain, &policy,
	FLOW_BLOCK_BIND);
	break;
	case NFT_MSG_DELCHAIN:
	if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
	continue;

	policy = nft_trans_chain_policy(trans);
	err = nft_flow_offload_chain(trans->ctx.chain, &policy,
	FLOW_BLOCK_UNBIND);
	break;
	case NFT_MSG_NEWRULE:
	if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
	continue;

	if (trans->ctx.flags & NLM_F_REPLACE \|\|
	!(trans->ctx.flags & NLM_F_APPEND)) {
	err = -EOPNOTSUPP;
	break;
	}
	err = nft_flow_offload_rule(trans->ctx.chain,
	nft_trans_rule(trans),
	nft_trans_flow_rule(trans),
	FLOW_CLS_REPLACE);
	break;
	case NFT_MSG_DELRULE:
	if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
	continue;

	err = nft_flow_offload_rule(trans->ctx.chain,
	nft_trans_rule(trans),
	nft_trans_flow_rule(trans),
	FLOW_CLS_DESTROY);
	break;
	}

	if (err)
	break;
	}

	list_for_each_entry(trans, &net->nft.commit_list, list) {
	if (trans->ctx.family != NFPROTO_NETDEV)
	continue;

	switch (trans->msg_type) {
	case NFT_MSG_NEWRULE:
	if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
	continue;

	nft_flow_rule_destroy(nft_trans_flow_rule(trans));
	break;
	default:
	break;
	}
	}

	return err;
	}

	static struct nft_chain __nft_offload_get_chain(struct net_device dev)
	{
	struct nft_base_chain *basechain;
	struct net *net = dev_net(dev);
	const struct nft_table *table;
	struct nft_chain *chain;

	list_for_each_entry(table, &net->nft.tables, list) {
	if (table->family != NFPROTO_NETDEV)
	continue;

	list_for_each_entry(chain, &table->chains, list) {
	if (!nft_is_base_chain(chain) \|\|
	!(chain->flags & NFT_CHAIN_HW_OFFLOAD))
	continue;

	basechain = nft_base_chain(chain);
	if (strncmp(basechain->dev_name, dev->name, IFNAMSIZ))
	continue;

	return chain;
	}
	}

	return NULL;
	}

	static void nft_indr_block_cb(struct net_device *dev,
	flow_indr_block_bind_cb_t cb, void cb_priv,
	enum flow_block_command cmd)
	{
	struct net *net = dev_net(dev);
	struct nft_chain *chain;

	mutex_lock(&net->nft.commit_mutex);
	chain = __nft_offload_get_chain(dev);
	if (chain && chain->flags & NFT_CHAIN_HW_OFFLOAD) {
	struct nft_base_chain *basechain;

	basechain = nft_base_chain(chain);
	nft_indr_block_ing_cmd(dev, basechain, cb, cb_priv, cmd);
	}
	mutex_unlock(&net->nft.commit_mutex);
	}

	static void nft_offload_chain_clean(struct nft_chain *chain)
	{
	struct nft_rule *rule;

	list_for_each_entry(rule, &chain->rules, list) {
	nft_flow_offload_rule(chain, rule,
	NULL, FLOW_CLS_DESTROY);
	}

	nft_flow_offload_chain(chain, NULL, FLOW_BLOCK_UNBIND);
	}

	static int nft_offload_netdev_event(struct notifier_block *this,
	unsigned long event, void *ptr)
	{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	struct net *net = dev_net(dev);
	struct nft_chain *chain;

	if (event != NETDEV_UNREGISTER)
	return NOTIFY_DONE;

	mutex_lock(&net->nft.commit_mutex);
	chain = __nft_offload_get_chain(dev);
	if (chain)
	nft_offload_chain_clean(chain);
	mutex_unlock(&net->nft.commit_mutex);

	return NOTIFY_DONE;
	}

	static struct flow_indr_block_entry block_ing_entry = {
	.cb = nft_indr_block_cb,
	.list = LIST_HEAD_INIT(block_ing_entry.list),
	};

	static struct notifier_block nft_offload_netdev_notifier = {
	.notifier_call = nft_offload_netdev_event,
	};

	int nft_offload_init(void)
	{
	int err;

	err = register_netdevice_notifier(&nft_offload_netdev_notifier);
	if (err < 0)
	return err;

	flow_indr_add_block_cb(&block_ing_entry);

	return 0;
	}

	void nft_offload_exit(void)
	{
	flow_indr_del_block_cb(&block_ing_entry);
	unregister_netdevice_notifier(&nft_offload_netdev_notifier);
	}