kernel/bpf/offload.c - third_party/linux - Git at Google

 /*
  * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
  * source tree.
  *
  * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
  * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
  * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
  * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  */

 #include <linux/bpf.h>
 #include <linux/bpf_verifier.h>
 #include <linux/bug.h>
 #include <linux/kdev_t.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
 #include <linux/proc_ns.h>
 #include <linux/rtnetlink.h>
 #include <linux/rwsem.h>

 /* Protects bpf_prog_offload_devs, bpf_map_offload_devs and offload members
  * of all progs.
  * RTNL lock cannot be taken when holding this lock.
  */
 static DECLARE_RWSEM(bpf_devs_lock);
 static LIST_HEAD(bpf_prog_offload_devs);
 static LIST_HEAD(bpf_map_offload_devs);

 static int bpf_dev_offload_check(struct net_device *netdev)
 {
 	if (!netdev)
 		return -EINVAL;
 	if (!netdev->netdev_ops->ndo_bpf)
 		return -EOPNOTSUPP;
 	return 0;
 }

 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 {
 	struct bpf_prog_offload *offload;
 	int err;

 	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
 	    attr->prog_type != BPF_PROG_TYPE_XDP)
 		return -EINVAL;

 	if (attr->prog_flags)
 		return -EINVAL;

 	offload = kzalloc(sizeof(*offload), GFP_USER);
 	if (!offload)
 		return -ENOMEM;

 	offload->prog = prog;

 	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
 					   attr->prog_ifindex);
 	err = bpf_dev_offload_check(offload->netdev);
 	if (err)
 		goto err_maybe_put;

 	down_write(&bpf_devs_lock);
 	if (offload->netdev->reg_state != NETREG_REGISTERED) {
 		err = -EINVAL;
 		goto err_unlock;
 	}
 	prog->aux->offload = offload;
 	list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
 	dev_put(offload->netdev);
 	up_write(&bpf_devs_lock);

 	return 0;
 err_unlock:
 	up_write(&bpf_devs_lock);
 err_maybe_put:
 	if (offload->netdev)
 		dev_put(offload->netdev);
 	kfree(offload);
 	return err;
 }

 static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
 			     struct netdev_bpf *data)
 {
 	struct bpf_prog_offload *offload = prog->aux->offload;
 	struct net_device *netdev;

 	ASSERT_RTNL();

 	if (!offload)
 		return -ENODEV;
 	netdev = offload->netdev;

 	data->command = cmd;

 	return netdev->netdev_ops->ndo_bpf(netdev, data);
 }

 int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
 {
 	struct netdev_bpf data = {};
 	int err;

 	data.verifier.prog = env->prog;

 	rtnl_lock();
 	err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data);
 	if (err)
 		goto exit_unlock;

 	env->prog->aux->offload->dev_ops = data.verifier.ops;
 	env->prog->aux->offload->dev_state = true;
 exit_unlock:
 	rtnl_unlock();
 	return err;
 }

 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
 				 int insn_idx, int prev_insn_idx)
 {
 	struct bpf_prog_offload *offload;
 	int ret = -ENODEV;

 	down_read(&bpf_devs_lock);
 	offload = env->prog->aux->offload;
 	if (offload)
 		ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
 {
 	struct bpf_prog_offload *offload = prog->aux->offload;
 	struct netdev_bpf data = {};

 	data.offload.prog = prog;

 	if (offload->dev_state)
 		WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));

 	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
 	bpf_prog_free_id(prog, true);

 	list_del_init(&offload->offloads);
 	kfree(offload);
 	prog->aux->offload = NULL;
 }

 void bpf_prog_offload_destroy(struct bpf_prog *prog)
 {
 	rtnl_lock();
 	down_write(&bpf_devs_lock);
 	if (prog->aux->offload)
 		__bpf_prog_offload_destroy(prog);
 	up_write(&bpf_devs_lock);
 	rtnl_unlock();
 }

 static int bpf_prog_offload_translate(struct bpf_prog *prog)
 {
 	struct netdev_bpf data = {};
 	int ret;

 	data.offload.prog = prog;

 	rtnl_lock();
 	ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
 	rtnl_unlock();

 	return ret;
 }

 static unsigned int bpf_prog_warn_on_exec(const void *ctx,
 					  const struct bpf_insn *insn)
 {
 	WARN(1, "attempt to execute device eBPF program on the host!");
 	return 0;
 }

 int bpf_prog_offload_compile(struct bpf_prog *prog)
 {
 	prog->bpf_func = bpf_prog_warn_on_exec;

 	return bpf_prog_offload_translate(prog);
 }

 struct ns_get_path_bpf_prog_args {
 	struct bpf_prog *prog;
 	struct bpf_prog_info *info;
 };

 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
 {
 	struct ns_get_path_bpf_prog_args *args = private_data;
 	struct bpf_prog_aux *aux = args->prog->aux;
 	struct ns_common *ns;
 	struct net *net;

 	rtnl_lock();
 	down_read(&bpf_devs_lock);

 	if (aux->offload) {
 		args->info->ifindex = aux->offload->netdev->ifindex;
 		net = dev_net(aux->offload->netdev);
 		get_net(net);
 		ns = &net->ns;
 	} else {
 		args->info->ifindex = 0;
 		ns = NULL;
 	}

 	up_read(&bpf_devs_lock);
 	rtnl_unlock();

 	return ns;
 }

 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
 			       struct bpf_prog *prog)
 {
 	struct ns_get_path_bpf_prog_args args = {
 		.prog	= prog,
 		.info	= info,
 	};
 	struct bpf_prog_aux *aux = prog->aux;
 	struct inode *ns_inode;
 	struct path ns_path;
 	char __user *uinsns;
 	void *res;
 	u32 ulen;

 	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
 	if (IS_ERR(res)) {
 		if (!info->ifindex)
 			return -ENODEV;
 		return PTR_ERR(res);
 	}

 	down_read(&bpf_devs_lock);

 	if (!aux->offload) {
 		up_read(&bpf_devs_lock);
 		return -ENODEV;
 	}

 	ulen = info->jited_prog_len;
 	info->jited_prog_len = aux->offload->jited_len;
 	if (info->jited_prog_len & ulen) {
 		uinsns = u64_to_user_ptr(info->jited_prog_insns);
 		ulen = min_t(u32, info->jited_prog_len, ulen);
 		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
 			up_read(&bpf_devs_lock);
 			return -EFAULT;
 		}
 	}

 	up_read(&bpf_devs_lock);

 	ns_inode = ns_path.dentry->d_inode;
 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
 	info->netns_ino = ns_inode->i_ino;
 	path_put(&ns_path);

 	return 0;
 }

 const struct bpf_prog_ops bpf_offload_prog_ops = {
 };

 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
 			       enum bpf_netdev_command cmd)
 {
 	struct netdev_bpf data = {};
 	struct net_device *netdev;

 	ASSERT_RTNL();

 	data.command = cmd;
 	data.offmap = offmap;
 	/* Caller must make sure netdev is valid */
 	netdev = offmap->netdev;

 	return netdev->netdev_ops->ndo_bpf(netdev, &data);
 }

 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
 {
 	struct net *net = current->nsproxy->net_ns;
 	struct bpf_offloaded_map *offmap;
 	int err;

 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
 	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
 	    attr->map_type != BPF_MAP_TYPE_HASH)
 		return ERR_PTR(-EINVAL);

 	offmap = kzalloc(sizeof(*offmap), GFP_USER);
 	if (!offmap)
 		return ERR_PTR(-ENOMEM);

 	bpf_map_init_from_attr(&offmap->map, attr);

 	rtnl_lock();
 	down_write(&bpf_devs_lock);
 	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
 	err = bpf_dev_offload_check(offmap->netdev);
 	if (err)
 		goto err_unlock;

 	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
 	if (err)
 		goto err_unlock;

 	list_add_tail(&offmap->offloads, &bpf_map_offload_devs);
 	up_write(&bpf_devs_lock);
 	rtnl_unlock();

 	return &offmap->map;

 err_unlock:
 	up_write(&bpf_devs_lock);
 	rtnl_unlock();
 	kfree(offmap);
 	return ERR_PTR(err);
 }

 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
 {
 	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
 	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
 	bpf_map_free_id(&offmap->map, true);
 	list_del_init(&offmap->offloads);
 	offmap->netdev = NULL;
 }

 void bpf_map_offload_map_free(struct bpf_map *map)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);

 	rtnl_lock();
 	down_write(&bpf_devs_lock);
 	if (offmap->netdev)
 		__bpf_map_offload_destroy(offmap);
 	up_write(&bpf_devs_lock);
 	rtnl_unlock();

 	kfree(offmap);
 }

 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
 	int ret = -ENODEV;

 	down_read(&bpf_devs_lock);
 	if (offmap->netdev)
 		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 int bpf_map_offload_update_elem(struct bpf_map *map,
 				void *key, void *value, u64 flags)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
 	int ret = -ENODEV;

 	if (unlikely(flags > BPF_EXIST))
 		return -EINVAL;

 	down_read(&bpf_devs_lock);
 	if (offmap->netdev)
 		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
 						       flags);
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
 	int ret = -ENODEV;

 	down_read(&bpf_devs_lock);
 	if (offmap->netdev)
 		ret = offmap->dev_ops->map_delete_elem(offmap, key);
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
 	int ret = -ENODEV;

 	down_read(&bpf_devs_lock);
 	if (offmap->netdev)
 		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 struct ns_get_path_bpf_map_args {
 	struct bpf_offloaded_map *offmap;
 	struct bpf_map_info *info;
 };

 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
 {
 	struct ns_get_path_bpf_map_args *args = private_data;
 	struct ns_common *ns;
 	struct net *net;

 	rtnl_lock();
 	down_read(&bpf_devs_lock);

 	if (args->offmap->netdev) {
 		args->info->ifindex = args->offmap->netdev->ifindex;
 		net = dev_net(args->offmap->netdev);
 		get_net(net);
 		ns = &net->ns;
 	} else {
 		args->info->ifindex = 0;
 		ns = NULL;
 	}

 	up_read(&bpf_devs_lock);
 	rtnl_unlock();

 	return ns;
 }

 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
 {
 	struct ns_get_path_bpf_map_args args = {
 		.offmap	= map_to_offmap(map),
 		.info	= info,
 	};
 	struct inode *ns_inode;
 	struct path ns_path;
 	void *res;

 	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
 	if (IS_ERR(res)) {
 		if (!info->ifindex)
 			return -ENODEV;
 		return PTR_ERR(res);
 	}

 	ns_inode = ns_path.dentry->d_inode;
 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
 	info->netns_ino = ns_inode->i_ino;
 	path_put(&ns_path);

 	return 0;
 }

 bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map)
 {
 	struct bpf_offloaded_map *offmap;
 	struct bpf_prog_offload *offload;
 	bool ret;

 	if (!bpf_prog_is_dev_bound(prog->aux))
 		return false;
 	if (!bpf_map_is_dev_bound(map))
 		return bpf_map_offload_neutral(map);

 	down_read(&bpf_devs_lock);
 	offload = prog->aux->offload;
 	offmap = map_to_offmap(map);

 	ret = offload && offload->netdev == offmap->netdev;
 	up_read(&bpf_devs_lock);

 	return ret;
 }

 static void bpf_offload_orphan_all_progs(struct net_device *netdev)
 {
 	struct bpf_prog_offload *offload, *tmp;

 	list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs, offloads)
 		if (offload->netdev == netdev)
 			__bpf_prog_offload_destroy(offload->prog);
 }

 static void bpf_offload_orphan_all_maps(struct net_device *netdev)
 {
 	struct bpf_offloaded_map *offmap, *tmp;

 	list_for_each_entry_safe(offmap, tmp, &bpf_map_offload_devs, offloads)
 		if (offmap->netdev == netdev)
 			__bpf_map_offload_destroy(offmap);
 }

 static int bpf_offload_notification(struct notifier_block *notifier,
 				    ulong event, void *ptr)
 {
 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);

 	ASSERT_RTNL();

 	switch (event) {
 	case NETDEV_UNREGISTER:
 		/* ignore namespace changes */
 		if (netdev->reg_state != NETREG_UNREGISTERING)
 			break;

 		down_write(&bpf_devs_lock);
 		bpf_offload_orphan_all_progs(netdev);
 		bpf_offload_orphan_all_maps(netdev);
 		up_write(&bpf_devs_lock);
 		break;
 	default:
 		break;
 	}
 	return NOTIFY_OK;
 }

 static struct notifier_block bpf_offload_notifier = {
 	.notifier_call = bpf_offload_notification,
 };

 static int __init bpf_offload_init(void)
 {
 	register_netdevice_notifier(&bpf_offload_notifier);
 	return 0;
 }

 subsys_initcall(bpf_offload_init);
	/*
	* Copyright (C) 2017-2018 Netronome Systems, Inc.
	*
	* This software is licensed under the GNU General License Version 2,
	* June 1991 as shown in the file COPYING in the top-level directory of this
	* source tree.
	*
	* THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
	* WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
	* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	* FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
	* OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
	* THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
	*/

	#include <linux/bpf.h>
	#include <linux/bpf_verifier.h>
	#include <linux/bug.h>
	#include <linux/kdev_t.h>
	#include <linux/list.h>
	#include <linux/netdevice.h>
	#include <linux/printk.h>
	#include <linux/proc_ns.h>
	#include <linux/rtnetlink.h>
	#include <linux/rwsem.h>

	/* Protects bpf_prog_offload_devs, bpf_map_offload_devs and offload members
	* of all progs.
	* RTNL lock cannot be taken when holding this lock.
	*/
	static DECLARE_RWSEM(bpf_devs_lock);
	static LIST_HEAD(bpf_prog_offload_devs);
	static LIST_HEAD(bpf_map_offload_devs);

	static int bpf_dev_offload_check(struct net_device *netdev)
	{
	if (!netdev)
	return -EINVAL;
	if (!netdev->netdev_ops->ndo_bpf)
	return -EOPNOTSUPP;
	return 0;
	}

	int bpf_prog_offload_init(struct bpf_prog prog, union bpf_attr attr)
	{
	struct bpf_prog_offload *offload;
	int err;

	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
	attr->prog_type != BPF_PROG_TYPE_XDP)
	return -EINVAL;

	if (attr->prog_flags)
	return -EINVAL;

	offload = kzalloc(sizeof(*offload), GFP_USER);
	if (!offload)
	return -ENOMEM;

	offload->prog = prog;

	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
	attr->prog_ifindex);
	err = bpf_dev_offload_check(offload->netdev);
	if (err)
	goto err_maybe_put;

	down_write(&bpf_devs_lock);
	if (offload->netdev->reg_state != NETREG_REGISTERED) {
	err = -EINVAL;
	goto err_unlock;
	}
	prog->aux->offload = offload;
	list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
	dev_put(offload->netdev);
	up_write(&bpf_devs_lock);

	return 0;
	err_unlock:
	up_write(&bpf_devs_lock);
	err_maybe_put:
	if (offload->netdev)
	dev_put(offload->netdev);
	kfree(offload);
	return err;
	}

	static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
	struct netdev_bpf *data)
	{
	struct bpf_prog_offload *offload = prog->aux->offload;
	struct net_device *netdev;

	ASSERT_RTNL();

	if (!offload)
	return -ENODEV;
	netdev = offload->netdev;

	data->command = cmd;

	return netdev->netdev_ops->ndo_bpf(netdev, data);
	}

	int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
	{
	struct netdev_bpf data = {};
	int err;

	data.verifier.prog = env->prog;

	rtnl_lock();
	err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data);
	if (err)
	goto exit_unlock;

	env->prog->aux->offload->dev_ops = data.verifier.ops;
	env->prog->aux->offload->dev_state = true;
	exit_unlock:
	rtnl_unlock();
	return err;
	}

	int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
	int insn_idx, int prev_insn_idx)
	{
	struct bpf_prog_offload *offload;
	int ret = -ENODEV;

	down_read(&bpf_devs_lock);
	offload = env->prog->aux->offload;
	if (offload)
	ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
	up_read(&bpf_devs_lock);

	return ret;
	}

	static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
	{
	struct bpf_prog_offload *offload = prog->aux->offload;
	struct netdev_bpf data = {};

	data.offload.prog = prog;

	if (offload->dev_state)
	WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));

	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
	bpf_prog_free_id(prog, true);

	list_del_init(&offload->offloads);
	kfree(offload);
	prog->aux->offload = NULL;
	}

	void bpf_prog_offload_destroy(struct bpf_prog *prog)
	{
	rtnl_lock();
	down_write(&bpf_devs_lock);
	if (prog->aux->offload)
	__bpf_prog_offload_destroy(prog);
	up_write(&bpf_devs_lock);
	rtnl_unlock();
	}

	static int bpf_prog_offload_translate(struct bpf_prog *prog)
	{
	struct netdev_bpf data = {};
	int ret;

	data.offload.prog = prog;

	rtnl_lock();
	ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
	rtnl_unlock();

	return ret;
	}

	static unsigned int bpf_prog_warn_on_exec(const void *ctx,
	const struct bpf_insn *insn)
	{
	WARN(1, "attempt to execute device eBPF program on the host!");
	return 0;
	}

	int bpf_prog_offload_compile(struct bpf_prog *prog)
	{
	prog->bpf_func = bpf_prog_warn_on_exec;

	return bpf_prog_offload_translate(prog);
	}

	struct ns_get_path_bpf_prog_args {
	struct bpf_prog *prog;
	struct bpf_prog_info *info;
	};

	static struct ns_common bpf_prog_offload_info_fill_ns(void private_data)
	{
	struct ns_get_path_bpf_prog_args *args = private_data;
	struct bpf_prog_aux *aux = args->prog->aux;
	struct ns_common *ns;
	struct net *net;

	rtnl_lock();
	down_read(&bpf_devs_lock);

	if (aux->offload) {
	args->info->ifindex = aux->offload->netdev->ifindex;
	net = dev_net(aux->offload->netdev);
	get_net(net);
	ns = &net->ns;
	} else {
	args->info->ifindex = 0;
	ns = NULL;
	}

	up_read(&bpf_devs_lock);
	rtnl_unlock();

	return ns;
	}

	int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
	struct bpf_prog *prog)
	{
	struct ns_get_path_bpf_prog_args args = {
	.prog = prog,
	.info = info,
	};
	struct bpf_prog_aux *aux = prog->aux;
	struct inode *ns_inode;
	struct path ns_path;
	char __user *uinsns;
	void *res;
	u32 ulen;

	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
	if (IS_ERR(res)) {
	if (!info->ifindex)
	return -ENODEV;
	return PTR_ERR(res);
	}

	down_read(&bpf_devs_lock);

	if (!aux->offload) {
	up_read(&bpf_devs_lock);
	return -ENODEV;
	}

	ulen = info->jited_prog_len;
	info->jited_prog_len = aux->offload->jited_len;
	if (info->jited_prog_len & ulen) {
	uinsns = u64_to_user_ptr(info->jited_prog_insns);
	ulen = min_t(u32, info->jited_prog_len, ulen);
	if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
	up_read(&bpf_devs_lock);
	return -EFAULT;
	}
	}

	up_read(&bpf_devs_lock);

	ns_inode = ns_path.dentry->d_inode;
	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
	info->netns_ino = ns_inode->i_ino;
	path_put(&ns_path);

	return 0;
	}

	const struct bpf_prog_ops bpf_offload_prog_ops = {
	};

	static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
	enum bpf_netdev_command cmd)
	{
	struct netdev_bpf data = {};
	struct net_device *netdev;

	ASSERT_RTNL();

	data.command = cmd;
	data.offmap = offmap;
	/* Caller must make sure netdev is valid */
	netdev = offmap->netdev;

	return netdev->netdev_ops->ndo_bpf(netdev, &data);
	}

	struct bpf_map bpf_map_offload_map_alloc(union bpf_attr attr)
	{
	struct net *net = current->nsproxy->net_ns;
	struct bpf_offloaded_map *offmap;
	int err;

	if (!capable(CAP_SYS_ADMIN))
	return ERR_PTR(-EPERM);
	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
	attr->map_type != BPF_MAP_TYPE_HASH)
	return ERR_PTR(-EINVAL);

	offmap = kzalloc(sizeof(*offmap), GFP_USER);
	if (!offmap)
	return ERR_PTR(-ENOMEM);

	bpf_map_init_from_attr(&offmap->map, attr);

	rtnl_lock();
	down_write(&bpf_devs_lock);
	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
	err = bpf_dev_offload_check(offmap->netdev);
	if (err)
	goto err_unlock;

	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
	if (err)
	goto err_unlock;

	list_add_tail(&offmap->offloads, &bpf_map_offload_devs);
	up_write(&bpf_devs_lock);
	rtnl_unlock();

	return &offmap->map;

	err_unlock:
	up_write(&bpf_devs_lock);
	rtnl_unlock();
	kfree(offmap);
	return ERR_PTR(err);
	}

	static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
	{
	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
	bpf_map_free_id(&offmap->map, true);
	list_del_init(&offmap->offloads);
	offmap->netdev = NULL;
	}

	void bpf_map_offload_map_free(struct bpf_map *map)
	{
	struct bpf_offloaded_map *offmap = map_to_offmap(map);

	rtnl_lock();
	down_write(&bpf_devs_lock);
	if (offmap->netdev)
	__bpf_map_offload_destroy(offmap);
	up_write(&bpf_devs_lock);
	rtnl_unlock();

	kfree(offmap);
	}

	int bpf_map_offload_lookup_elem(struct bpf_map map, void key, void *value)
	{
	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	int ret = -ENODEV;

	down_read(&bpf_devs_lock);
	if (offmap->netdev)
	ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
	up_read(&bpf_devs_lock);

	return ret;
	}

	int bpf_map_offload_update_elem(struct bpf_map *map,
	void key, void value, u64 flags)
	{
	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	int ret = -ENODEV;

	if (unlikely(flags > BPF_EXIST))
	return -EINVAL;

	down_read(&bpf_devs_lock);
	if (offmap->netdev)
	ret = offmap->dev_ops->map_update_elem(offmap, key, value,
	flags);
	up_read(&bpf_devs_lock);

	return ret;
	}

	int bpf_map_offload_delete_elem(struct bpf_map map, void key)
	{
	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	int ret = -ENODEV;

	down_read(&bpf_devs_lock);
	if (offmap->netdev)
	ret = offmap->dev_ops->map_delete_elem(offmap, key);
	up_read(&bpf_devs_lock);

	return ret;
	}

	int bpf_map_offload_get_next_key(struct bpf_map map, void key, void *next_key)
	{
	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	int ret = -ENODEV;

	down_read(&bpf_devs_lock);
	if (offmap->netdev)
	ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
	up_read(&bpf_devs_lock);

	return ret;
	}

	struct ns_get_path_bpf_map_args {
	struct bpf_offloaded_map *offmap;
	struct bpf_map_info *info;
	};

	static struct ns_common bpf_map_offload_info_fill_ns(void private_data)
	{
	struct ns_get_path_bpf_map_args *args = private_data;
	struct ns_common *ns;
	struct net *net;

	rtnl_lock();
	down_read(&bpf_devs_lock);

	if (args->offmap->netdev) {
	args->info->ifindex = args->offmap->netdev->ifindex;
	net = dev_net(args->offmap->netdev);
	get_net(net);
	ns = &net->ns;
	} else {
	args->info->ifindex = 0;
	ns = NULL;
	}

	up_read(&bpf_devs_lock);
	rtnl_unlock();

	return ns;
	}

	int bpf_map_offload_info_fill(struct bpf_map_info info, struct bpf_map map)
	{
	struct ns_get_path_bpf_map_args args = {
	.offmap = map_to_offmap(map),
	.info = info,
	};
	struct inode *ns_inode;
	struct path ns_path;
	void *res;

	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
	if (IS_ERR(res)) {
	if (!info->ifindex)
	return -ENODEV;
	return PTR_ERR(res);
	}

	ns_inode = ns_path.dentry->d_inode;
	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
	info->netns_ino = ns_inode->i_ino;
	path_put(&ns_path);

	return 0;
	}

	bool bpf_offload_dev_match(struct bpf_prog prog, struct bpf_map map)
	{
	struct bpf_offloaded_map *offmap;
	struct bpf_prog_offload *offload;
	bool ret;

	if (!bpf_prog_is_dev_bound(prog->aux))
	return false;
	if (!bpf_map_is_dev_bound(map))
	return bpf_map_offload_neutral(map);

	down_read(&bpf_devs_lock);
	offload = prog->aux->offload;
	offmap = map_to_offmap(map);

	ret = offload && offload->netdev == offmap->netdev;
	up_read(&bpf_devs_lock);

	return ret;
	}

	static void bpf_offload_orphan_all_progs(struct net_device *netdev)
	{
	struct bpf_prog_offload offload, tmp;

	list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs, offloads)
	if (offload->netdev == netdev)
	__bpf_prog_offload_destroy(offload->prog);
	}

	static void bpf_offload_orphan_all_maps(struct net_device *netdev)
	{
	struct bpf_offloaded_map offmap, tmp;

	list_for_each_entry_safe(offmap, tmp, &bpf_map_offload_devs, offloads)
	if (offmap->netdev == netdev)
	__bpf_map_offload_destroy(offmap);
	}

	static int bpf_offload_notification(struct notifier_block *notifier,
	ulong event, void *ptr)
	{
	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);

	ASSERT_RTNL();

	switch (event) {
	case NETDEV_UNREGISTER:
	/* ignore namespace changes */
	if (netdev->reg_state != NETREG_UNREGISTERING)
	break;

	down_write(&bpf_devs_lock);
	bpf_offload_orphan_all_progs(netdev);
	bpf_offload_orphan_all_maps(netdev);
	up_write(&bpf_devs_lock);
	break;
	default:
	break;
	}
	return NOTIFY_OK;
	}

	static struct notifier_block bpf_offload_notifier = {
	.notifier_call = bpf_offload_notification,
	};

	static int __init bpf_offload_init(void)
	{
	register_netdevice_notifier(&bpf_offload_notifier);
	return 0;
	}

	subsys_initcall(bpf_offload_init);