[linux-2.6-block.git] / kernel / bpf / offload.c

/*
 * 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/lockdep.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/proc_ns.h>
#include <linux/rhashtable.h>
#include <linux/rtnetlink.h>
#include <linux/rwsem.h>

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

struct bpf_offload_dev {
	struct list_head netdevs;
};

struct bpf_offload_netdev {
	struct rhash_head l;
	struct net_device *netdev;
	struct bpf_offload_dev *offdev;
	struct list_head progs;
	struct list_head maps;
	struct list_head offdev_netdevs;
};

static const struct rhashtable_params offdevs_params = {
	.nelem_hint		= 4,
	.key_len		= sizeof(struct net_device *),
	.key_offset		= offsetof(struct bpf_offload_netdev, netdev),
	.head_offset		= offsetof(struct bpf_offload_netdev, l),
	.automatic_shrinking	= true,
};

static struct rhashtable offdevs;
static bool offdevs_inited;

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

static struct bpf_offload_netdev *
bpf_offload_find_netdev(struct net_device *netdev)
{
	lockdep_assert_held(&bpf_devs_lock);

	if (!offdevs_inited)
		return NULL;
	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
}

int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
{
	struct bpf_offload_netdev *ondev;
	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);
	ondev = bpf_offload_find_netdev(offload->netdev);
	if (!ondev) {
		err = -EINVAL;
		goto err_unlock;
	}
	prog->aux->offload = offload;
	list_add_tail(&offload->offloads, &ondev->progs);
	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;
}

int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
{
	struct bpf_prog_offload *offload;
	int ret = -ENODEV;

	down_read(&bpf_devs_lock);
	offload = env->prog->aux->offload;
	if (offload) {
		if (offload->dev_ops->finalize)
			ret = offload->dev_ops->finalize(env);
		else
			ret = 0;
	}
	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_offload_netdev *ondev;
	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;

	ondev = bpf_offload_find_netdev(offmap->netdev);
	if (!ondev) {
		err = -EINVAL;
		goto err_unlock;
	}

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

	list_add_tail(&offmap->offloads, &ondev->maps);
	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;
}

static bool __bpf_offload_dev_match(struct bpf_prog *prog,
				    struct net_device *netdev)
{
	struct bpf_offload_netdev *ondev1, *ondev2;
	struct bpf_prog_offload *offload;

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

	offload = prog->aux->offload;
	if (!offload)
		return false;
	if (offload->netdev == netdev)
		return true;

	ondev1 = bpf_offload_find_netdev(offload->netdev);
	ondev2 = bpf_offload_find_netdev(netdev);

	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
}

bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
{
	bool ret;

	down_read(&bpf_devs_lock);
	ret = __bpf_offload_dev_match(prog, netdev);
	up_read(&bpf_devs_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(bpf_offload_dev_match);

bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
{
	struct bpf_offloaded_map *offmap;
	bool ret;

	if (!bpf_map_is_dev_bound(map))
		return bpf_map_offload_neutral(map);
	offmap = map_to_offmap(map);

	down_read(&bpf_devs_lock);
	ret = __bpf_offload_dev_match(prog, offmap->netdev);
	up_read(&bpf_devs_lock);

	return ret;
}

int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
				    struct net_device *netdev)
{
	struct bpf_offload_netdev *ondev;
	int err;

	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
	if (!ondev)
		return -ENOMEM;

	ondev->netdev = netdev;
	ondev->offdev = offdev;
	INIT_LIST_HEAD(&ondev->progs);
	INIT_LIST_HEAD(&ondev->maps);

	down_write(&bpf_devs_lock);
	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
	if (err) {
		netdev_warn(netdev, "failed to register for BPF offload\n");
		goto err_unlock_free;
	}

	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
	up_write(&bpf_devs_lock);
	return 0;

err_unlock_free:
	up_write(&bpf_devs_lock);
	kfree(ondev);
	return err;
}
EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);

void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
				       struct net_device *netdev)
{
	struct bpf_offload_netdev *ondev, *altdev;
	struct bpf_offloaded_map *offmap, *mtmp;
	struct bpf_prog_offload *offload, *ptmp;

	ASSERT_RTNL();

	down_write(&bpf_devs_lock);
	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
	if (WARN_ON(!ondev))
		goto unlock;

	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
	list_del(&ondev->offdev_netdevs);

	/* Try to move the objects to another netdev of the device */
	altdev = list_first_entry_or_null(&offdev->netdevs,
					  struct bpf_offload_netdev,
					  offdev_netdevs);
	if (altdev) {
		list_for_each_entry(offload, &ondev->progs, offloads)
			offload->netdev = altdev->netdev;
		list_splice_init(&ondev->progs, &altdev->progs);

		list_for_each_entry(offmap, &ondev->maps, offloads)
			offmap->netdev = altdev->netdev;
		list_splice_init(&ondev->maps, &altdev->maps);
	} else {
		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
			__bpf_prog_offload_destroy(offload->prog);
		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
			__bpf_map_offload_destroy(offmap);
	}

	WARN_ON(!list_empty(&ondev->progs));
	WARN_ON(!list_empty(&ondev->maps));
	kfree(ondev);
unlock:
	up_write(&bpf_devs_lock);
}
EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);

struct bpf_offload_dev *bpf_offload_dev_create(void)
{
	struct bpf_offload_dev *offdev;
	int err;

	down_write(&bpf_devs_lock);
	if (!offdevs_inited) {
		err = rhashtable_init(&offdevs, &offdevs_params);
		if (err)
			return ERR_PTR(err);
		offdevs_inited = true;
	}
	up_write(&bpf_devs_lock);

	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
	if (!offdev)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&offdev->netdevs);

	return offdev;
}
EXPORT_SYMBOL_GPL(bpf_offload_dev_create);

void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
{
	WARN_ON(!list_empty(&offdev->netdevs));
	kfree(offdev);
}
EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
Commit	Line	Data
a39e17b2	1	/*
0cd3cbed	2	* Copyright (C) 2017-2018 Netronome Systems, Inc.
a39e17b2 JK	3	*
	4	* This software is licensed under the GNU General License Version 2,
	5	* June 1991 as shown in the file COPYING in the top-level directory of this
	6	* source tree.
	7	*
	8	* THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
	9	* WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
	10	* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	11	* FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
	12	* OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
	13	* THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
	14	*/
	15
ab3f0063 JK	16	#include <linux/bpf.h>
	17	#include <linux/bpf_verifier.h>
	18	#include <linux/bug.h>
675fc275	19	#include <linux/kdev_t.h>
ab3f0063	20	#include <linux/list.h>
9fd7c555	21	#include <linux/lockdep.h>
ab3f0063 JK	22	#include <linux/netdevice.h>
ab3f0063 JK	23	#include <linux/printk.h>
675fc275	24	#include <linux/proc_ns.h>
9fd7c555	25	#include <linux/rhashtable.h>
ab3f0063	26	#include <linux/rtnetlink.h>
e0d3974a	27	#include <linux/rwsem.h>
ab3f0063	28
9fd7c555	29	/* Protects offdevs, members of bpf_offload_netdev and offload members
a3884572	30	* of all progs.
e0d3974a JK	31	* RTNL lock cannot be taken when holding this lock.
	32	*/
	33	static DECLARE_RWSEM(bpf_devs_lock);
9fd7c555	34
602144c2 JK	35	struct bpf_offload_dev {
	36	struct list_head netdevs;
	37	};
	38
9fd7c555 JK	39	struct bpf_offload_netdev {
	40	struct rhash_head l;
	41	struct net_device *netdev;
602144c2	42	struct bpf_offload_dev *offdev;
9fd7c555 JK	43	struct list_head progs;
9fd7c555 JK	44	struct list_head maps;
602144c2	45	struct list_head offdev_netdevs;
9fd7c555 JK	46	};
	47
	48	static const struct rhashtable_params offdevs_params = {
	49	.nelem_hint = 4,
	50	.key_len = sizeof(struct net_device *),
	51	.key_offset = offsetof(struct bpf_offload_netdev, netdev),
	52	.head_offset = offsetof(struct bpf_offload_netdev, l),
	53	.automatic_shrinking = true,
	54	};
	55
	56	static struct rhashtable offdevs;
	57	static bool offdevs_inited;
ab3f0063	58
5bc2d55c JK	59	static int bpf_dev_offload_check(struct net_device *netdev)
	60	{
	61	if (!netdev)
	62	return -EINVAL;
	63	if (!netdev->netdev_ops->ndo_bpf)
	64	return -EOPNOTSUPP;
	65	return 0;
	66	}
	67
9fd7c555 JK	68	static struct bpf_offload_netdev *
	69	bpf_offload_find_netdev(struct net_device *netdev)
	70	{
	71	lockdep_assert_held(&bpf_devs_lock);
	72
	73	if (!offdevs_inited)
	74	return NULL;
	75	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
	76	}
	77
ab3f0063 JK	78	int bpf_prog_offload_init(struct bpf_prog prog, union bpf_attr attr)
ab3f0063 JK	79	{
9fd7c555	80	struct bpf_offload_netdev *ondev;
0a9c1991	81	struct bpf_prog_offload *offload;
5bc2d55c	82	int err;
ab3f0063	83
649f11dc JK	84	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
	85	attr->prog_type != BPF_PROG_TYPE_XDP)
	86	return -EINVAL;
ab3f0063 JK	87
	88	if (attr->prog_flags)
	89	return -EINVAL;
	90
	91	offload = kzalloc(sizeof(*offload), GFP_USER);
	92	if (!offload)
	93	return -ENOMEM;
	94
	95	offload->prog = prog;
ab3f0063	96
e0d3974a JK	97	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
e0d3974a JK	98	attr->prog_ifindex);
5bc2d55c JK	99	err = bpf_dev_offload_check(offload->netdev);
	100	if (err)
	101	goto err_maybe_put;
ab3f0063	102
e0d3974a	103	down_write(&bpf_devs_lock);
9fd7c555 JK	104	ondev = bpf_offload_find_netdev(offload->netdev);
9fd7c555 JK	105	if (!ondev) {
5bc2d55c	106	err = -EINVAL;
e0d3974a	107	goto err_unlock;
5bc2d55c	108	}
ab3f0063	109	prog->aux->offload = offload;
9fd7c555	110	list_add_tail(&offload->offloads, &ondev->progs);
e0d3974a JK	111	dev_put(offload->netdev);
e0d3974a JK	112	up_write(&bpf_devs_lock);
ab3f0063 JK	113
ab3f0063 JK	114	return 0;
e0d3974a JK	115	err_unlock:
e0d3974a JK	116	up_write(&bpf_devs_lock);
5bc2d55c JK	117	err_maybe_put:
	118	if (offload->netdev)
	119	dev_put(offload->netdev);
e0d3974a	120	kfree(offload);
5bc2d55c	121	return err;
ab3f0063 JK	122	}
	123
	124	static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
	125	struct netdev_bpf *data)
	126	{
0a9c1991	127	struct bpf_prog_offload *offload = prog->aux->offload;
ce3b9db4	128	struct net_device *netdev;
ab3f0063 JK	129
	130	ASSERT_RTNL();
	131
ce3b9db4	132	if (!offload)
ab3f0063	133	return -ENODEV;
ce3b9db4	134	netdev = offload->netdev;
ab3f0063 JK	135
	136	data->command = cmd;
	137
	138	return netdev->netdev_ops->ndo_bpf(netdev, data);
	139	}
	140
	141	int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
	142	{
	143	struct netdev_bpf data = {};
	144	int err;
	145
	146	data.verifier.prog = env->prog;
	147
	148	rtnl_lock();
	149	err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data);
	150	if (err)
	151	goto exit_unlock;
	152
cae1927c	153	env->prog->aux->offload->dev_ops = data.verifier.ops;
ab3f0063	154	env->prog->aux->offload->dev_state = true;
ab3f0063 JK	155	exit_unlock:
	156	rtnl_unlock();
	157	return err;
	158	}
	159
cae1927c JK	160	int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
	161	int insn_idx, int prev_insn_idx)
	162	{
0a9c1991	163	struct bpf_prog_offload *offload;
cae1927c JK	164	int ret = -ENODEV;
	165
	166	down_read(&bpf_devs_lock);
	167	offload = env->prog->aux->offload;
ce3b9db4	168	if (offload)
cae1927c JK	169	ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
	170	up_read(&bpf_devs_lock);
	171
	172	return ret;
	173	}
	174
c941ce9c QM	175	int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
	176	{
	177	struct bpf_prog_offload *offload;
	178	int ret = -ENODEV;
	179
	180	down_read(&bpf_devs_lock);
	181	offload = env->prog->aux->offload;
	182	if (offload) {
	183	if (offload->dev_ops->finalize)
	184	ret = offload->dev_ops->finalize(env);
	185	else
	186	ret = 0;
	187	}
	188	up_read(&bpf_devs_lock);
	189
	190	return ret;
	191	}
	192
ab3f0063 JK	193	static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
ab3f0063 JK	194	{
0a9c1991	195	struct bpf_prog_offload *offload = prog->aux->offload;
ab3f0063 JK	196	struct netdev_bpf data = {};
	197
	198	data.offload.prog = prog;
	199
ab3f0063 JK	200	if (offload->dev_state)
	201	WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
	202
ad8ad79f JK	203	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
	204	bpf_prog_free_id(prog, true);
	205
ab3f0063	206	list_del_init(&offload->offloads);
ce3b9db4 JK	207	kfree(offload);
ce3b9db4 JK	208	prog->aux->offload = NULL;
ab3f0063 JK	209	}
	210
	211	void bpf_prog_offload_destroy(struct bpf_prog *prog)
	212	{
ab3f0063	213	rtnl_lock();
e0d3974a	214	down_write(&bpf_devs_lock);
ce3b9db4 JK	215	if (prog->aux->offload)
ce3b9db4 JK	216	__bpf_prog_offload_destroy(prog);
e0d3974a	217	up_write(&bpf_devs_lock);
ab3f0063	218	rtnl_unlock();
ab3f0063 JK	219	}
	220
	221	static int bpf_prog_offload_translate(struct bpf_prog *prog)
	222	{
ab3f0063 JK	223	struct netdev_bpf data = {};
	224	int ret;
	225
	226	data.offload.prog = prog;
	227
ab3f0063 JK	228	rtnl_lock();
	229	ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
	230	rtnl_unlock();
	231
	232	return ret;
	233	}
	234
	235	static unsigned int bpf_prog_warn_on_exec(const void *ctx,
	236	const struct bpf_insn *insn)
	237	{
	238	WARN(1, "attempt to execute device eBPF program on the host!");
	239	return 0;
	240	}
	241
	242	int bpf_prog_offload_compile(struct bpf_prog *prog)
	243	{
	244	prog->bpf_func = bpf_prog_warn_on_exec;
	245
	246	return bpf_prog_offload_translate(prog);
	247	}
	248
675fc275 JK	249	struct ns_get_path_bpf_prog_args {
	250	struct bpf_prog *prog;
	251	struct bpf_prog_info *info;
	252	};
	253
	254	static struct ns_common bpf_prog_offload_info_fill_ns(void private_data)
	255	{
	256	struct ns_get_path_bpf_prog_args *args = private_data;
	257	struct bpf_prog_aux *aux = args->prog->aux;
	258	struct ns_common *ns;
	259	struct net *net;
	260
	261	rtnl_lock();
	262	down_read(&bpf_devs_lock);
	263
	264	if (aux->offload) {
	265	args->info->ifindex = aux->offload->netdev->ifindex;
	266	net = dev_net(aux->offload->netdev);
	267	get_net(net);
	268	ns = &net->ns;
	269	} else {
	270	args->info->ifindex = 0;
	271	ns = NULL;
	272	}
	273
	274	up_read(&bpf_devs_lock);
	275	rtnl_unlock();
	276
	277	return ns;
	278	}
	279
	280	int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
	281	struct bpf_prog *prog)
	282	{
	283	struct ns_get_path_bpf_prog_args args = {
	284	.prog = prog,
	285	.info = info,
	286	};
fcfb126d	287	struct bpf_prog_aux *aux = prog->aux;
675fc275 JK	288	struct inode *ns_inode;
675fc275 JK	289	struct path ns_path;
fcfb126d	290	char __user *uinsns;
675fc275	291	void *res;
fcfb126d	292	u32 ulen;
675fc275 JK	293
	294	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
	295	if (IS_ERR(res)) {
	296	if (!info->ifindex)
	297	return -ENODEV;
	298	return PTR_ERR(res);
	299	}
	300
fcfb126d JW	301	down_read(&bpf_devs_lock);
	302
	303	if (!aux->offload) {
	304	up_read(&bpf_devs_lock);
	305	return -ENODEV;
	306	}
	307
	308	ulen = info->jited_prog_len;
	309	info->jited_prog_len = aux->offload->jited_len;
	310	if (info->jited_prog_len & ulen) {
	311	uinsns = u64_to_user_ptr(info->jited_prog_insns);
	312	ulen = min_t(u32, info->jited_prog_len, ulen);
	313	if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
	314	up_read(&bpf_devs_lock);
	315	return -EFAULT;
	316	}
	317	}
	318
	319	up_read(&bpf_devs_lock);
	320
675fc275 JK	321	ns_inode = ns_path.dentry->d_inode;
	322	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
	323	info->netns_ino = ns_inode->i_ino;
	324	path_put(&ns_path);
	325
	326	return 0;
	327	}
	328
ab3f0063 JK	329	const struct bpf_prog_ops bpf_offload_prog_ops = {
	330	};
	331
a3884572 JK	332	static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
	333	enum bpf_netdev_command cmd)
	334	{
	335	struct netdev_bpf data = {};
	336	struct net_device *netdev;
	337
	338	ASSERT_RTNL();
	339
	340	data.command = cmd;
	341	data.offmap = offmap;
	342	/* Caller must make sure netdev is valid */
	343	netdev = offmap->netdev;
	344
	345	return netdev->netdev_ops->ndo_bpf(netdev, &data);
	346	}
	347
	348	struct bpf_map bpf_map_offload_map_alloc(union bpf_attr attr)
	349	{
	350	struct net *net = current->nsproxy->net_ns;
9fd7c555	351	struct bpf_offload_netdev *ondev;
a3884572 JK	352	struct bpf_offloaded_map *offmap;
	353	int err;
	354
	355	if (!capable(CAP_SYS_ADMIN))
	356	return ERR_PTR(-EPERM);
7a0ef693 JK	357	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
7a0ef693 JK	358	attr->map_type != BPF_MAP_TYPE_HASH)
a3884572 JK	359	return ERR_PTR(-EINVAL);
	360
	361	offmap = kzalloc(sizeof(*offmap), GFP_USER);
	362	if (!offmap)
	363	return ERR_PTR(-ENOMEM);
	364
	365	bpf_map_init_from_attr(&offmap->map, attr);
	366
	367	rtnl_lock();
	368	down_write(&bpf_devs_lock);
	369	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
	370	err = bpf_dev_offload_check(offmap->netdev);
	371	if (err)
	372	goto err_unlock;
	373
9fd7c555 JK	374	ondev = bpf_offload_find_netdev(offmap->netdev);
	375	if (!ondev) {
	376	err = -EINVAL;
	377	goto err_unlock;
	378	}
	379
a3884572 JK	380	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
	381	if (err)
	382	goto err_unlock;
	383
9fd7c555	384	list_add_tail(&offmap->offloads, &ondev->maps);
a3884572 JK	385	up_write(&bpf_devs_lock);
	386	rtnl_unlock();
	387
	388	return &offmap->map;
	389
	390	err_unlock:
	391	up_write(&bpf_devs_lock);
	392	rtnl_unlock();
	393	kfree(offmap);
	394	return ERR_PTR(err);
	395	}
	396
	397	static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
	398	{
	399	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
	400	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
	401	bpf_map_free_id(&offmap->map, true);
	402	list_del_init(&offmap->offloads);
	403	offmap->netdev = NULL;
	404	}
	405
	406	void bpf_map_offload_map_free(struct bpf_map *map)
	407	{
	408	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	409
	410	rtnl_lock();
	411	down_write(&bpf_devs_lock);
	412	if (offmap->netdev)
	413	__bpf_map_offload_destroy(offmap);
	414	up_write(&bpf_devs_lock);
	415	rtnl_unlock();
	416
	417	kfree(offmap);
	418	}
	419
	420	int bpf_map_offload_lookup_elem(struct bpf_map map, void key, void *value)
	421	{
	422	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	423	int ret = -ENODEV;
	424
	425	down_read(&bpf_devs_lock);
	426	if (offmap->netdev)
	427	ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
	428	up_read(&bpf_devs_lock);
	429
	430	return ret;
	431	}
	432
	433	int bpf_map_offload_update_elem(struct bpf_map *map,
	434	void key, void value, u64 flags)
	435	{
	436	struct bpf_offloaded_map *offmap = map_to_offmap(map);
	437	int ret = -ENODEV;
	438
	439	if (unlikely(flags > BPF_EXIST))
	440	return -EINVAL;
	441
	442	down_read(&bpf_devs_lock);
	443	if (offmap->netdev)
	444	ret = offmap->dev_ops->map_update_elem(offmap, key, value,
	445	flags);
	446	up_read(&bpf_devs_lock);
	447
	448	return ret;
449	}
450
451	int bpf_map_offload_delete_elem(struct bpf_map map, void key)
452	{
453	struct bpf_offloaded_map *offmap = map_to_offmap(map);
454	int ret = -ENODEV;
455
456	down_read(&bpf_devs_lock);
457	if (offmap->netdev)
458	ret = offmap->dev_ops->map_delete_elem(offmap, key);
459	up_read(&bpf_devs_lock);
460
461	return ret;
462	}
463
464	int bpf_map_offload_get_next_key(struct bpf_map map, void key, void *next_key)
465	{
466	struct bpf_offloaded_map *offmap = map_to_offmap(map);
467	int ret = -ENODEV;
468
469	down_read(&bpf_devs_lock);
470	if (offmap->netdev)
471	ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
472	up_read(&bpf_devs_lock);
473
474	return ret;
475	}
476
52775b33 JK	477	struct ns_get_path_bpf_map_args {
	478	struct bpf_offloaded_map *offmap;
	479	struct bpf_map_info *info;
	480	};
	481
	482	static struct ns_common bpf_map_offload_info_fill_ns(void private_data)
	483	{
	484	struct ns_get_path_bpf_map_args *args = private_data;
	485	struct ns_common *ns;
	486	struct net *net;
	487
	488	rtnl_lock();
	489	down_read(&bpf_devs_lock);
	490
	491	if (args->offmap->netdev) {
	492	args->info->ifindex = args->offmap->netdev->ifindex;
	493	net = dev_net(args->offmap->netdev);
	494	get_net(net);
	495	ns = &net->ns;
	496	} else {
	497	args->info->ifindex = 0;
	498	ns = NULL;
	499	}
	500
	501	up_read(&bpf_devs_lock);
	502	rtnl_unlock();
	503
	504	return ns;
	505	}
	506
	507	int bpf_map_offload_info_fill(struct bpf_map_info info, struct bpf_map map)
	508	{
	509	struct ns_get_path_bpf_map_args args = {
	510	.offmap = map_to_offmap(map),
	511	.info = info,
	512	};
	513	struct inode *ns_inode;
	514	struct path ns_path;
	515	void *res;
	516
	517	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
	518	if (IS_ERR(res)) {
	519	if (!info->ifindex)
	520	return -ENODEV;
	521	return PTR_ERR(res);
	522	}
	523
	524	ns_inode = ns_path.dentry->d_inode;
	525	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
	526	info->netns_ino = ns_inode->i_ino;
	527	path_put(&ns_path);
	528
	529	return 0;
	530	}
	531
fd4f227d JK	532	static bool __bpf_offload_dev_match(struct bpf_prog *prog,
fd4f227d JK	533	struct net_device *netdev)
a3884572	534	{
fd4f227d	535	struct bpf_offload_netdev ondev1, ondev2;
a3884572	536	struct bpf_prog_offload *offload;
a3884572	537
0cd3cbed	538	if (!bpf_prog_is_dev_bound(prog->aux))
a3884572	539	return false;
a3884572	540
a3884572	541	offload = prog->aux->offload;
fd4f227d JK	542	if (!offload)
	543	return false;
	544	if (offload->netdev == netdev)
	545	return true;
	546
	547	ondev1 = bpf_offload_find_netdev(offload->netdev);
	548	ondev2 = bpf_offload_find_netdev(netdev);
	549
	550	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
	551	}
	552
	553	bool bpf_offload_dev_match(struct bpf_prog prog, struct net_device netdev)
	554	{
	555	bool ret;
	556
	557	down_read(&bpf_devs_lock);
	558	ret = __bpf_offload_dev_match(prog, netdev);
	559	up_read(&bpf_devs_lock);
	560
	561	return ret;
	562	}
	563	EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
	564
	565	bool bpf_offload_prog_map_match(struct bpf_prog prog, struct bpf_map map)
	566	{
	567	struct bpf_offloaded_map *offmap;
	568	bool ret;
	569
	570	if (!bpf_map_is_dev_bound(map))
	571	return bpf_map_offload_neutral(map);
a3884572 JK	572	offmap = map_to_offmap(map);
a3884572 JK	573
fd4f227d JK	574	down_read(&bpf_devs_lock);
fd4f227d JK	575	ret = __bpf_offload_dev_match(prog, offmap->netdev);
a3884572 JK	576	up_read(&bpf_devs_lock);
	577
	578	return ret;
	579	}
	580
602144c2 JK	581	int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
602144c2 JK	582	struct net_device *netdev)
a3884572	583	{
9fd7c555 JK	584	struct bpf_offload_netdev *ondev;
9fd7c555 JK	585	int err;
a3884572	586
9fd7c555 JK	587	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
	588	if (!ondev)
	589	return -ENOMEM;
	590
	591	ondev->netdev = netdev;
602144c2	592	ondev->offdev = offdev;
9fd7c555 JK	593	INIT_LIST_HEAD(&ondev->progs);
	594	INIT_LIST_HEAD(&ondev->maps);
	595
	596	down_write(&bpf_devs_lock);
	597	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
	598	if (err) {
	599	netdev_warn(netdev, "failed to register for BPF offload\n");
	600	goto err_unlock_free;
	601	}
a3884572	602
602144c2	603	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
9fd7c555 JK	604	up_write(&bpf_devs_lock);
	605	return 0;
	606
	607	err_unlock_free:
	608	up_write(&bpf_devs_lock);
	609	kfree(ondev);
	610	return err;
a3884572	611	}
9fd7c555	612	EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
a3884572	613
602144c2 JK	614	void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
602144c2 JK	615	struct net_device *netdev)
ab3f0063	616	{
602144c2	617	struct bpf_offload_netdev ondev, altdev;
9fd7c555 JK	618	struct bpf_offloaded_map offmap, mtmp;
9fd7c555 JK	619	struct bpf_prog_offload offload, ptmp;
ab3f0063 JK	620
	621	ASSERT_RTNL();
	622
9fd7c555 JK	623	down_write(&bpf_devs_lock);
	624	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
	625	if (WARN_ON(!ondev))
	626	goto unlock;
ab3f0063	627
9fd7c555	628	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
602144c2 JK	629	list_del(&ondev->offdev_netdevs);
	630
	631	/* Try to move the objects to another netdev of the device */
	632	altdev = list_first_entry_or_null(&offdev->netdevs,
	633	struct bpf_offload_netdev,
	634	offdev_netdevs);
	635	if (altdev) {
	636	list_for_each_entry(offload, &ondev->progs, offloads)
	637	offload->netdev = altdev->netdev;
	638	list_splice_init(&ondev->progs, &altdev->progs);
	639
	640	list_for_each_entry(offmap, &ondev->maps, offloads)
	641	offmap->netdev = altdev->netdev;
	642	list_splice_init(&ondev->maps, &altdev->maps);
	643	} else {
	644	list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
	645	__bpf_prog_offload_destroy(offload->prog);
	646	list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
	647	__bpf_map_offload_destroy(offmap);
	648	}
ab3f0063	649
9fd7c555 JK	650	WARN_ON(!list_empty(&ondev->progs));
	651	WARN_ON(!list_empty(&ondev->maps));
	652	kfree(ondev);
	653	unlock:
	654	up_write(&bpf_devs_lock);
	655	}
	656	EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
602144c2 JK	657
	658	struct bpf_offload_dev *bpf_offload_dev_create(void)
	659	{
	660	struct bpf_offload_dev *offdev;
	661	int err;
	662
	663	down_write(&bpf_devs_lock);
	664	if (!offdevs_inited) {
	665	err = rhashtable_init(&offdevs, &offdevs_params);
	666	if (err)
	667	return ERR_PTR(err);
	668	offdevs_inited = true;
	669	}
	670	up_write(&bpf_devs_lock);
	671
	672	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
	673	if (!offdev)
	674	return ERR_PTR(-ENOMEM);
	675
	676	INIT_LIST_HEAD(&offdev->netdevs);
	677
	678	return offdev;
	679	}
	680	EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
	681
	682	void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
	683	{
	684	WARN_ON(!list_empty(&offdev->netdevs));
	685	kfree(offdev);
	686	}
	687	EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);