1 /*
2  * Copyright (C) 2017-2018 Netronome Systems, Inc.
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 
16 #include <linux/bpf.h>
17 #include <linux/bpf_verifier.h>
18 #include <linux/bug.h>
19 #include <linux/kdev_t.h>
20 #include <linux/list.h>
21 #include <linux/lockdep.h>
22 #include <linux/netdevice.h>
23 #include <linux/printk.h>
24 #include <linux/proc_ns.h>
25 #include <linux/rhashtable.h>
26 #include <linux/rtnetlink.h>
27 #include <linux/rwsem.h>
28 
29 /* Protects offdevs, members of bpf_offload_netdev and offload members
30  * of all progs.
31  * RTNL lock cannot be taken when holding this lock.
32  */
33 static DECLARE_RWSEM(bpf_devs_lock);
34 
35 struct bpf_offload_dev {
36 	const struct bpf_prog_offload_ops *ops;
37 	struct list_head netdevs;
38 	void *priv;
39 };
40 
41 struct bpf_offload_netdev {
42 	struct rhash_head l;
43 	struct net_device *netdev;
44 	struct bpf_offload_dev *offdev;
45 	struct list_head progs;
46 	struct list_head maps;
47 	struct list_head offdev_netdevs;
48 };
49 
50 static const struct rhashtable_params offdevs_params = {
51 	.nelem_hint		= 4,
52 	.key_len		= sizeof(struct net_device *),
53 	.key_offset		= offsetof(struct bpf_offload_netdev, netdev),
54 	.head_offset		= offsetof(struct bpf_offload_netdev, l),
55 	.automatic_shrinking	= true,
56 };
57 
58 static struct rhashtable offdevs;
59 static bool offdevs_inited;
60 
bpf_dev_offload_check(struct net_device * netdev)61 static int bpf_dev_offload_check(struct net_device *netdev)
62 {
63 	if (!netdev)
64 		return -EINVAL;
65 	if (!netdev->netdev_ops->ndo_bpf)
66 		return -EOPNOTSUPP;
67 	return 0;
68 }
69 
70 static struct bpf_offload_netdev *
bpf_offload_find_netdev(struct net_device * netdev)71 bpf_offload_find_netdev(struct net_device *netdev)
72 {
73 	lockdep_assert_held(&bpf_devs_lock);
74 
75 	if (!offdevs_inited)
76 		return NULL;
77 	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
78 }
79 
bpf_prog_offload_init(struct bpf_prog * prog,union bpf_attr * attr)80 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
81 {
82 	struct bpf_offload_netdev *ondev;
83 	struct bpf_prog_offload *offload;
84 	int err;
85 
86 	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
87 	    attr->prog_type != BPF_PROG_TYPE_XDP)
88 		return -EINVAL;
89 
90 	if (attr->prog_flags)
91 		return -EINVAL;
92 
93 	offload = kzalloc(sizeof(*offload), GFP_USER);
94 	if (!offload)
95 		return -ENOMEM;
96 
97 	offload->prog = prog;
98 
99 	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
100 					   attr->prog_ifindex);
101 	err = bpf_dev_offload_check(offload->netdev);
102 	if (err)
103 		goto err_maybe_put;
104 
105 	down_write(&bpf_devs_lock);
106 	ondev = bpf_offload_find_netdev(offload->netdev);
107 	if (!ondev) {
108 		err = -EINVAL;
109 		goto err_unlock;
110 	}
111 	offload->offdev = ondev->offdev;
112 	prog->aux->offload = offload;
113 	list_add_tail(&offload->offloads, &ondev->progs);
114 	dev_put(offload->netdev);
115 	up_write(&bpf_devs_lock);
116 
117 	return 0;
118 err_unlock:
119 	up_write(&bpf_devs_lock);
120 err_maybe_put:
121 	if (offload->netdev)
122 		dev_put(offload->netdev);
123 	kfree(offload);
124 	return err;
125 }
126 
bpf_prog_offload_verifier_prep(struct bpf_prog * prog)127 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
128 {
129 	struct bpf_prog_offload *offload;
130 	int ret = -ENODEV;
131 
132 	down_read(&bpf_devs_lock);
133 	offload = prog->aux->offload;
134 	if (offload) {
135 		ret = offload->offdev->ops->prepare(prog);
136 		offload->dev_state = !ret;
137 	}
138 	up_read(&bpf_devs_lock);
139 
140 	return ret;
141 }
142 
bpf_prog_offload_verify_insn(struct bpf_verifier_env * env,int insn_idx,int prev_insn_idx)143 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
144 				 int insn_idx, int prev_insn_idx)
145 {
146 	struct bpf_prog_offload *offload;
147 	int ret = -ENODEV;
148 
149 	down_read(&bpf_devs_lock);
150 	offload = env->prog->aux->offload;
151 	if (offload)
152 		ret = offload->offdev->ops->insn_hook(env, insn_idx,
153 						      prev_insn_idx);
154 	up_read(&bpf_devs_lock);
155 
156 	return ret;
157 }
158 
bpf_prog_offload_finalize(struct bpf_verifier_env * env)159 int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
160 {
161 	struct bpf_prog_offload *offload;
162 	int ret = -ENODEV;
163 
164 	down_read(&bpf_devs_lock);
165 	offload = env->prog->aux->offload;
166 	if (offload) {
167 		if (offload->offdev->ops->finalize)
168 			ret = offload->offdev->ops->finalize(env);
169 		else
170 			ret = 0;
171 	}
172 	up_read(&bpf_devs_lock);
173 
174 	return ret;
175 }
176 
177 void
bpf_prog_offload_replace_insn(struct bpf_verifier_env * env,u32 off,struct bpf_insn * insn)178 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
179 			      struct bpf_insn *insn)
180 {
181 	const struct bpf_prog_offload_ops *ops;
182 	struct bpf_prog_offload *offload;
183 	int ret = -EOPNOTSUPP;
184 
185 	down_read(&bpf_devs_lock);
186 	offload = env->prog->aux->offload;
187 	if (offload) {
188 		ops = offload->offdev->ops;
189 		if (!offload->opt_failed && ops->replace_insn)
190 			ret = ops->replace_insn(env, off, insn);
191 		offload->opt_failed |= ret;
192 	}
193 	up_read(&bpf_devs_lock);
194 }
195 
196 void
bpf_prog_offload_remove_insns(struct bpf_verifier_env * env,u32 off,u32 cnt)197 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
198 {
199 	struct bpf_prog_offload *offload;
200 	int ret = -EOPNOTSUPP;
201 
202 	down_read(&bpf_devs_lock);
203 	offload = env->prog->aux->offload;
204 	if (offload) {
205 		if (!offload->opt_failed && offload->offdev->ops->remove_insns)
206 			ret = offload->offdev->ops->remove_insns(env, off, cnt);
207 		offload->opt_failed |= ret;
208 	}
209 	up_read(&bpf_devs_lock);
210 }
211 
__bpf_prog_offload_destroy(struct bpf_prog * prog)212 static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
213 {
214 	struct bpf_prog_offload *offload = prog->aux->offload;
215 
216 	if (offload->dev_state)
217 		offload->offdev->ops->destroy(prog);
218 
219 	list_del_init(&offload->offloads);
220 	kfree(offload);
221 	prog->aux->offload = NULL;
222 }
223 
bpf_prog_offload_destroy(struct bpf_prog * prog)224 void bpf_prog_offload_destroy(struct bpf_prog *prog)
225 {
226 	down_write(&bpf_devs_lock);
227 	if (prog->aux->offload)
228 		__bpf_prog_offload_destroy(prog);
229 	up_write(&bpf_devs_lock);
230 }
231 
bpf_prog_offload_translate(struct bpf_prog * prog)232 static int bpf_prog_offload_translate(struct bpf_prog *prog)
233 {
234 	struct bpf_prog_offload *offload;
235 	int ret = -ENODEV;
236 
237 	down_read(&bpf_devs_lock);
238 	offload = prog->aux->offload;
239 	if (offload)
240 		ret = offload->offdev->ops->translate(prog);
241 	up_read(&bpf_devs_lock);
242 
243 	return ret;
244 }
245 
bpf_prog_warn_on_exec(const void * ctx,const struct bpf_insn * insn)246 static unsigned int bpf_prog_warn_on_exec(const void *ctx,
247 					  const struct bpf_insn *insn)
248 {
249 	WARN(1, "attempt to execute device eBPF program on the host!");
250 	return 0;
251 }
252 
bpf_prog_offload_compile(struct bpf_prog * prog)253 int bpf_prog_offload_compile(struct bpf_prog *prog)
254 {
255 	prog->bpf_func = bpf_prog_warn_on_exec;
256 
257 	return bpf_prog_offload_translate(prog);
258 }
259 
260 struct ns_get_path_bpf_prog_args {
261 	struct bpf_prog *prog;
262 	struct bpf_prog_info *info;
263 };
264 
bpf_prog_offload_info_fill_ns(void * private_data)265 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
266 {
267 	struct ns_get_path_bpf_prog_args *args = private_data;
268 	struct bpf_prog_aux *aux = args->prog->aux;
269 	struct ns_common *ns;
270 	struct net *net;
271 
272 	rtnl_lock();
273 	down_read(&bpf_devs_lock);
274 
275 	if (aux->offload) {
276 		args->info->ifindex = aux->offload->netdev->ifindex;
277 		net = dev_net(aux->offload->netdev);
278 		get_net(net);
279 		ns = &net->ns;
280 	} else {
281 		args->info->ifindex = 0;
282 		ns = NULL;
283 	}
284 
285 	up_read(&bpf_devs_lock);
286 	rtnl_unlock();
287 
288 	return ns;
289 }
290 
bpf_prog_offload_info_fill(struct bpf_prog_info * info,struct bpf_prog * prog)291 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
292 			       struct bpf_prog *prog)
293 {
294 	struct ns_get_path_bpf_prog_args args = {
295 		.prog	= prog,
296 		.info	= info,
297 	};
298 	struct bpf_prog_aux *aux = prog->aux;
299 	struct inode *ns_inode;
300 	struct path ns_path;
301 	char __user *uinsns;
302 	int res;
303 	u32 ulen;
304 
305 	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
306 	if (res) {
307 		if (!info->ifindex)
308 			return -ENODEV;
309 		return res;
310 	}
311 
312 	down_read(&bpf_devs_lock);
313 
314 	if (!aux->offload) {
315 		up_read(&bpf_devs_lock);
316 		return -ENODEV;
317 	}
318 
319 	ulen = info->jited_prog_len;
320 	info->jited_prog_len = aux->offload->jited_len;
321 	if (info->jited_prog_len && ulen) {
322 		uinsns = u64_to_user_ptr(info->jited_prog_insns);
323 		ulen = min_t(u32, info->jited_prog_len, ulen);
324 		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
325 			up_read(&bpf_devs_lock);
326 			return -EFAULT;
327 		}
328 	}
329 
330 	up_read(&bpf_devs_lock);
331 
332 	ns_inode = ns_path.dentry->d_inode;
333 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
334 	info->netns_ino = ns_inode->i_ino;
335 	path_put(&ns_path);
336 
337 	return 0;
338 }
339 
340 const struct bpf_prog_ops bpf_offload_prog_ops = {
341 };
342 
bpf_map_offload_ndo(struct bpf_offloaded_map * offmap,enum bpf_netdev_command cmd)343 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
344 			       enum bpf_netdev_command cmd)
345 {
346 	struct netdev_bpf data = {};
347 	struct net_device *netdev;
348 
349 	ASSERT_RTNL();
350 
351 	data.command = cmd;
352 	data.offmap = offmap;
353 	/* Caller must make sure netdev is valid */
354 	netdev = offmap->netdev;
355 
356 	return netdev->netdev_ops->ndo_bpf(netdev, &data);
357 }
358 
bpf_map_offload_map_alloc(union bpf_attr * attr)359 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
360 {
361 	struct net *net = current->nsproxy->net_ns;
362 	struct bpf_offload_netdev *ondev;
363 	struct bpf_offloaded_map *offmap;
364 	int err;
365 
366 	if (!capable(CAP_SYS_ADMIN))
367 		return ERR_PTR(-EPERM);
368 	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
369 	    attr->map_type != BPF_MAP_TYPE_HASH)
370 		return ERR_PTR(-EINVAL);
371 
372 	offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE);
373 	if (!offmap)
374 		return ERR_PTR(-ENOMEM);
375 
376 	bpf_map_init_from_attr(&offmap->map, attr);
377 
378 	rtnl_lock();
379 	down_write(&bpf_devs_lock);
380 	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
381 	err = bpf_dev_offload_check(offmap->netdev);
382 	if (err)
383 		goto err_unlock;
384 
385 	ondev = bpf_offload_find_netdev(offmap->netdev);
386 	if (!ondev) {
387 		err = -EINVAL;
388 		goto err_unlock;
389 	}
390 
391 	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
392 	if (err)
393 		goto err_unlock;
394 
395 	list_add_tail(&offmap->offloads, &ondev->maps);
396 	up_write(&bpf_devs_lock);
397 	rtnl_unlock();
398 
399 	return &offmap->map;
400 
401 err_unlock:
402 	up_write(&bpf_devs_lock);
403 	rtnl_unlock();
404 	bpf_map_area_free(offmap);
405 	return ERR_PTR(err);
406 }
407 
__bpf_map_offload_destroy(struct bpf_offloaded_map * offmap)408 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
409 {
410 	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
411 	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
412 	bpf_map_free_id(&offmap->map, true);
413 	list_del_init(&offmap->offloads);
414 	offmap->netdev = NULL;
415 }
416 
bpf_map_offload_map_free(struct bpf_map * map)417 void bpf_map_offload_map_free(struct bpf_map *map)
418 {
419 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
420 
421 	rtnl_lock();
422 	down_write(&bpf_devs_lock);
423 	if (offmap->netdev)
424 		__bpf_map_offload_destroy(offmap);
425 	up_write(&bpf_devs_lock);
426 	rtnl_unlock();
427 
428 	bpf_map_area_free(offmap);
429 }
430 
bpf_map_offload_lookup_elem(struct bpf_map * map,void * key,void * value)431 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
432 {
433 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
434 	int ret = -ENODEV;
435 
436 	down_read(&bpf_devs_lock);
437 	if (offmap->netdev)
438 		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
439 	up_read(&bpf_devs_lock);
440 
441 	return ret;
442 }
443 
bpf_map_offload_update_elem(struct bpf_map * map,void * key,void * value,u64 flags)444 int bpf_map_offload_update_elem(struct bpf_map *map,
445 				void *key, void *value, u64 flags)
446 {
447 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
448 	int ret = -ENODEV;
449 
450 	if (unlikely(flags > BPF_EXIST))
451 		return -EINVAL;
452 
453 	down_read(&bpf_devs_lock);
454 	if (offmap->netdev)
455 		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
456 						       flags);
457 	up_read(&bpf_devs_lock);
458 
459 	return ret;
460 }
461 
bpf_map_offload_delete_elem(struct bpf_map * map,void * key)462 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
463 {
464 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
465 	int ret = -ENODEV;
466 
467 	down_read(&bpf_devs_lock);
468 	if (offmap->netdev)
469 		ret = offmap->dev_ops->map_delete_elem(offmap, key);
470 	up_read(&bpf_devs_lock);
471 
472 	return ret;
473 }
474 
bpf_map_offload_get_next_key(struct bpf_map * map,void * key,void * next_key)475 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
476 {
477 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
478 	int ret = -ENODEV;
479 
480 	down_read(&bpf_devs_lock);
481 	if (offmap->netdev)
482 		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
483 	up_read(&bpf_devs_lock);
484 
485 	return ret;
486 }
487 
488 struct ns_get_path_bpf_map_args {
489 	struct bpf_offloaded_map *offmap;
490 	struct bpf_map_info *info;
491 };
492 
bpf_map_offload_info_fill_ns(void * private_data)493 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
494 {
495 	struct ns_get_path_bpf_map_args *args = private_data;
496 	struct ns_common *ns;
497 	struct net *net;
498 
499 	rtnl_lock();
500 	down_read(&bpf_devs_lock);
501 
502 	if (args->offmap->netdev) {
503 		args->info->ifindex = args->offmap->netdev->ifindex;
504 		net = dev_net(args->offmap->netdev);
505 		get_net(net);
506 		ns = &net->ns;
507 	} else {
508 		args->info->ifindex = 0;
509 		ns = NULL;
510 	}
511 
512 	up_read(&bpf_devs_lock);
513 	rtnl_unlock();
514 
515 	return ns;
516 }
517 
bpf_map_offload_info_fill(struct bpf_map_info * info,struct bpf_map * map)518 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
519 {
520 	struct ns_get_path_bpf_map_args args = {
521 		.offmap	= map_to_offmap(map),
522 		.info	= info,
523 	};
524 	struct inode *ns_inode;
525 	struct path ns_path;
526 	int res;
527 
528 	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
529 	if (res) {
530 		if (!info->ifindex)
531 			return -ENODEV;
532 		return res;
533 	}
534 
535 	ns_inode = ns_path.dentry->d_inode;
536 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
537 	info->netns_ino = ns_inode->i_ino;
538 	path_put(&ns_path);
539 
540 	return 0;
541 }
542 
__bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)543 static bool __bpf_offload_dev_match(struct bpf_prog *prog,
544 				    struct net_device *netdev)
545 {
546 	struct bpf_offload_netdev *ondev1, *ondev2;
547 	struct bpf_prog_offload *offload;
548 
549 	if (!bpf_prog_is_dev_bound(prog->aux))
550 		return false;
551 
552 	offload = prog->aux->offload;
553 	if (!offload)
554 		return false;
555 	if (offload->netdev == netdev)
556 		return true;
557 
558 	ondev1 = bpf_offload_find_netdev(offload->netdev);
559 	ondev2 = bpf_offload_find_netdev(netdev);
560 
561 	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
562 }
563 
bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)564 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
565 {
566 	bool ret;
567 
568 	down_read(&bpf_devs_lock);
569 	ret = __bpf_offload_dev_match(prog, netdev);
570 	up_read(&bpf_devs_lock);
571 
572 	return ret;
573 }
574 EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
575 
bpf_offload_prog_map_match(struct bpf_prog * prog,struct bpf_map * map)576 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
577 {
578 	struct bpf_offloaded_map *offmap;
579 	bool ret;
580 
581 	if (!bpf_map_is_dev_bound(map))
582 		return bpf_map_offload_neutral(map);
583 	offmap = map_to_offmap(map);
584 
585 	down_read(&bpf_devs_lock);
586 	ret = __bpf_offload_dev_match(prog, offmap->netdev);
587 	up_read(&bpf_devs_lock);
588 
589 	return ret;
590 }
591 
bpf_offload_dev_netdev_register(struct bpf_offload_dev * offdev,struct net_device * netdev)592 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
593 				    struct net_device *netdev)
594 {
595 	struct bpf_offload_netdev *ondev;
596 	int err;
597 
598 	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
599 	if (!ondev)
600 		return -ENOMEM;
601 
602 	ondev->netdev = netdev;
603 	ondev->offdev = offdev;
604 	INIT_LIST_HEAD(&ondev->progs);
605 	INIT_LIST_HEAD(&ondev->maps);
606 
607 	down_write(&bpf_devs_lock);
608 	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
609 	if (err) {
610 		netdev_warn(netdev, "failed to register for BPF offload\n");
611 		goto err_unlock_free;
612 	}
613 
614 	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
615 	up_write(&bpf_devs_lock);
616 	return 0;
617 
618 err_unlock_free:
619 	up_write(&bpf_devs_lock);
620 	kfree(ondev);
621 	return err;
622 }
623 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
624 
bpf_offload_dev_netdev_unregister(struct bpf_offload_dev * offdev,struct net_device * netdev)625 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
626 				       struct net_device *netdev)
627 {
628 	struct bpf_offload_netdev *ondev, *altdev;
629 	struct bpf_offloaded_map *offmap, *mtmp;
630 	struct bpf_prog_offload *offload, *ptmp;
631 
632 	ASSERT_RTNL();
633 
634 	down_write(&bpf_devs_lock);
635 	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
636 	if (WARN_ON(!ondev))
637 		goto unlock;
638 
639 	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
640 	list_del(&ondev->offdev_netdevs);
641 
642 	/* Try to move the objects to another netdev of the device */
643 	altdev = list_first_entry_or_null(&offdev->netdevs,
644 					  struct bpf_offload_netdev,
645 					  offdev_netdevs);
646 	if (altdev) {
647 		list_for_each_entry(offload, &ondev->progs, offloads)
648 			offload->netdev = altdev->netdev;
649 		list_splice_init(&ondev->progs, &altdev->progs);
650 
651 		list_for_each_entry(offmap, &ondev->maps, offloads)
652 			offmap->netdev = altdev->netdev;
653 		list_splice_init(&ondev->maps, &altdev->maps);
654 	} else {
655 		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
656 			__bpf_prog_offload_destroy(offload->prog);
657 		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
658 			__bpf_map_offload_destroy(offmap);
659 	}
660 
661 	WARN_ON(!list_empty(&ondev->progs));
662 	WARN_ON(!list_empty(&ondev->maps));
663 	kfree(ondev);
664 unlock:
665 	up_write(&bpf_devs_lock);
666 }
667 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
668 
669 struct bpf_offload_dev *
bpf_offload_dev_create(const struct bpf_prog_offload_ops * ops,void * priv)670 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
671 {
672 	struct bpf_offload_dev *offdev;
673 	int err;
674 
675 	down_write(&bpf_devs_lock);
676 	if (!offdevs_inited) {
677 		err = rhashtable_init(&offdevs, &offdevs_params);
678 		if (err) {
679 			up_write(&bpf_devs_lock);
680 			return ERR_PTR(err);
681 		}
682 		offdevs_inited = true;
683 	}
684 	up_write(&bpf_devs_lock);
685 
686 	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
687 	if (!offdev)
688 		return ERR_PTR(-ENOMEM);
689 
690 	offdev->ops = ops;
691 	offdev->priv = priv;
692 	INIT_LIST_HEAD(&offdev->netdevs);
693 
694 	return offdev;
695 }
696 EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
697 
bpf_offload_dev_destroy(struct bpf_offload_dev * offdev)698 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
699 {
700 	WARN_ON(!list_empty(&offdev->netdevs));
701 	kfree(offdev);
702 }
703 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
704 
bpf_offload_dev_priv(struct bpf_offload_dev * offdev)705 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
706 {
707 	return offdev->priv;
708 }
709 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
710