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 	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
220 	bpf_prog_free_id(prog, true);
221 
222 	list_del_init(&offload->offloads);
223 	kfree(offload);
224 	prog->aux->offload = NULL;
225 }
226 
bpf_prog_offload_destroy(struct bpf_prog * prog)227 void bpf_prog_offload_destroy(struct bpf_prog *prog)
228 {
229 	down_write(&bpf_devs_lock);
230 	if (prog->aux->offload)
231 		__bpf_prog_offload_destroy(prog);
232 	up_write(&bpf_devs_lock);
233 }
234 
bpf_prog_offload_translate(struct bpf_prog * prog)235 static int bpf_prog_offload_translate(struct bpf_prog *prog)
236 {
237 	struct bpf_prog_offload *offload;
238 	int ret = -ENODEV;
239 
240 	down_read(&bpf_devs_lock);
241 	offload = prog->aux->offload;
242 	if (offload)
243 		ret = offload->offdev->ops->translate(prog);
244 	up_read(&bpf_devs_lock);
245 
246 	return ret;
247 }
248 
bpf_prog_warn_on_exec(const void * ctx,const struct bpf_insn * insn)249 static unsigned int bpf_prog_warn_on_exec(const void *ctx,
250 					  const struct bpf_insn *insn)
251 {
252 	WARN(1, "attempt to execute device eBPF program on the host!");
253 	return 0;
254 }
255 
bpf_prog_offload_compile(struct bpf_prog * prog)256 int bpf_prog_offload_compile(struct bpf_prog *prog)
257 {
258 	prog->bpf_func = bpf_prog_warn_on_exec;
259 
260 	return bpf_prog_offload_translate(prog);
261 }
262 
263 struct ns_get_path_bpf_prog_args {
264 	struct bpf_prog *prog;
265 	struct bpf_prog_info *info;
266 };
267 
bpf_prog_offload_info_fill_ns(void * private_data)268 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
269 {
270 	struct ns_get_path_bpf_prog_args *args = private_data;
271 	struct bpf_prog_aux *aux = args->prog->aux;
272 	struct ns_common *ns;
273 	struct net *net;
274 
275 	rtnl_lock();
276 	down_read(&bpf_devs_lock);
277 
278 	if (aux->offload) {
279 		args->info->ifindex = aux->offload->netdev->ifindex;
280 		net = dev_net(aux->offload->netdev);
281 		get_net(net);
282 		ns = &net->ns;
283 	} else {
284 		args->info->ifindex = 0;
285 		ns = NULL;
286 	}
287 
288 	up_read(&bpf_devs_lock);
289 	rtnl_unlock();
290 
291 	return ns;
292 }
293 
bpf_prog_offload_info_fill(struct bpf_prog_info * info,struct bpf_prog * prog)294 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
295 			       struct bpf_prog *prog)
296 {
297 	struct ns_get_path_bpf_prog_args args = {
298 		.prog	= prog,
299 		.info	= info,
300 	};
301 	struct bpf_prog_aux *aux = prog->aux;
302 	struct inode *ns_inode;
303 	struct path ns_path;
304 	char __user *uinsns;
305 	int res;
306 	u32 ulen;
307 
308 	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
309 	if (res) {
310 		if (!info->ifindex)
311 			return -ENODEV;
312 		return res;
313 	}
314 
315 	down_read(&bpf_devs_lock);
316 
317 	if (!aux->offload) {
318 		up_read(&bpf_devs_lock);
319 		return -ENODEV;
320 	}
321 
322 	ulen = info->jited_prog_len;
323 	info->jited_prog_len = aux->offload->jited_len;
324 	if (info->jited_prog_len && ulen) {
325 		uinsns = u64_to_user_ptr(info->jited_prog_insns);
326 		ulen = min_t(u32, info->jited_prog_len, ulen);
327 		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
328 			up_read(&bpf_devs_lock);
329 			return -EFAULT;
330 		}
331 	}
332 
333 	up_read(&bpf_devs_lock);
334 
335 	ns_inode = ns_path.dentry->d_inode;
336 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
337 	info->netns_ino = ns_inode->i_ino;
338 	path_put(&ns_path);
339 
340 	return 0;
341 }
342 
343 const struct bpf_prog_ops bpf_offload_prog_ops = {
344 };
345 
bpf_map_offload_ndo(struct bpf_offloaded_map * offmap,enum bpf_netdev_command cmd)346 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
347 			       enum bpf_netdev_command cmd)
348 {
349 	struct netdev_bpf data = {};
350 	struct net_device *netdev;
351 
352 	ASSERT_RTNL();
353 
354 	data.command = cmd;
355 	data.offmap = offmap;
356 	/* Caller must make sure netdev is valid */
357 	netdev = offmap->netdev;
358 
359 	return netdev->netdev_ops->ndo_bpf(netdev, &data);
360 }
361 
bpf_map_offload_map_alloc(union bpf_attr * attr)362 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
363 {
364 	struct net *net = current->nsproxy->net_ns;
365 	struct bpf_offload_netdev *ondev;
366 	struct bpf_offloaded_map *offmap;
367 	int err;
368 
369 	if (!capable(CAP_SYS_ADMIN))
370 		return ERR_PTR(-EPERM);
371 	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
372 	    attr->map_type != BPF_MAP_TYPE_HASH)
373 		return ERR_PTR(-EINVAL);
374 
375 	offmap = kzalloc(sizeof(*offmap), GFP_USER);
376 	if (!offmap)
377 		return ERR_PTR(-ENOMEM);
378 
379 	bpf_map_init_from_attr(&offmap->map, attr);
380 
381 	rtnl_lock();
382 	down_write(&bpf_devs_lock);
383 	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
384 	err = bpf_dev_offload_check(offmap->netdev);
385 	if (err)
386 		goto err_unlock;
387 
388 	ondev = bpf_offload_find_netdev(offmap->netdev);
389 	if (!ondev) {
390 		err = -EINVAL;
391 		goto err_unlock;
392 	}
393 
394 	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
395 	if (err)
396 		goto err_unlock;
397 
398 	list_add_tail(&offmap->offloads, &ondev->maps);
399 	up_write(&bpf_devs_lock);
400 	rtnl_unlock();
401 
402 	return &offmap->map;
403 
404 err_unlock:
405 	up_write(&bpf_devs_lock);
406 	rtnl_unlock();
407 	kfree(offmap);
408 	return ERR_PTR(err);
409 }
410 
__bpf_map_offload_destroy(struct bpf_offloaded_map * offmap)411 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
412 {
413 	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
414 	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
415 	bpf_map_free_id(&offmap->map, true);
416 	list_del_init(&offmap->offloads);
417 	offmap->netdev = NULL;
418 }
419 
bpf_map_offload_map_free(struct bpf_map * map)420 void bpf_map_offload_map_free(struct bpf_map *map)
421 {
422 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
423 
424 	rtnl_lock();
425 	down_write(&bpf_devs_lock);
426 	if (offmap->netdev)
427 		__bpf_map_offload_destroy(offmap);
428 	up_write(&bpf_devs_lock);
429 	rtnl_unlock();
430 
431 	kfree(offmap);
432 }
433 
bpf_map_offload_lookup_elem(struct bpf_map * map,void * key,void * value)434 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
435 {
436 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
437 	int ret = -ENODEV;
438 
439 	down_read(&bpf_devs_lock);
440 	if (offmap->netdev)
441 		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
442 	up_read(&bpf_devs_lock);
443 
444 	return ret;
445 }
446 
bpf_map_offload_update_elem(struct bpf_map * map,void * key,void * value,u64 flags)447 int bpf_map_offload_update_elem(struct bpf_map *map,
448 				void *key, void *value, u64 flags)
449 {
450 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
451 	int ret = -ENODEV;
452 
453 	if (unlikely(flags > BPF_EXIST))
454 		return -EINVAL;
455 
456 	down_read(&bpf_devs_lock);
457 	if (offmap->netdev)
458 		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
459 						       flags);
460 	up_read(&bpf_devs_lock);
461 
462 	return ret;
463 }
464 
bpf_map_offload_delete_elem(struct bpf_map * map,void * key)465 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
466 {
467 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
468 	int ret = -ENODEV;
469 
470 	down_read(&bpf_devs_lock);
471 	if (offmap->netdev)
472 		ret = offmap->dev_ops->map_delete_elem(offmap, key);
473 	up_read(&bpf_devs_lock);
474 
475 	return ret;
476 }
477 
bpf_map_offload_get_next_key(struct bpf_map * map,void * key,void * next_key)478 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
479 {
480 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
481 	int ret = -ENODEV;
482 
483 	down_read(&bpf_devs_lock);
484 	if (offmap->netdev)
485 		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
486 	up_read(&bpf_devs_lock);
487 
488 	return ret;
489 }
490 
491 struct ns_get_path_bpf_map_args {
492 	struct bpf_offloaded_map *offmap;
493 	struct bpf_map_info *info;
494 };
495 
bpf_map_offload_info_fill_ns(void * private_data)496 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
497 {
498 	struct ns_get_path_bpf_map_args *args = private_data;
499 	struct ns_common *ns;
500 	struct net *net;
501 
502 	rtnl_lock();
503 	down_read(&bpf_devs_lock);
504 
505 	if (args->offmap->netdev) {
506 		args->info->ifindex = args->offmap->netdev->ifindex;
507 		net = dev_net(args->offmap->netdev);
508 		get_net(net);
509 		ns = &net->ns;
510 	} else {
511 		args->info->ifindex = 0;
512 		ns = NULL;
513 	}
514 
515 	up_read(&bpf_devs_lock);
516 	rtnl_unlock();
517 
518 	return ns;
519 }
520 
bpf_map_offload_info_fill(struct bpf_map_info * info,struct bpf_map * map)521 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
522 {
523 	struct ns_get_path_bpf_map_args args = {
524 		.offmap	= map_to_offmap(map),
525 		.info	= info,
526 	};
527 	struct inode *ns_inode;
528 	struct path ns_path;
529 	int res;
530 
531 	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
532 	if (res) {
533 		if (!info->ifindex)
534 			return -ENODEV;
535 		return res;
536 	}
537 
538 	ns_inode = ns_path.dentry->d_inode;
539 	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
540 	info->netns_ino = ns_inode->i_ino;
541 	path_put(&ns_path);
542 
543 	return 0;
544 }
545 
__bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)546 static bool __bpf_offload_dev_match(struct bpf_prog *prog,
547 				    struct net_device *netdev)
548 {
549 	struct bpf_offload_netdev *ondev1, *ondev2;
550 	struct bpf_prog_offload *offload;
551 
552 	if (!bpf_prog_is_dev_bound(prog->aux))
553 		return false;
554 
555 	offload = prog->aux->offload;
556 	if (!offload)
557 		return false;
558 	if (offload->netdev == netdev)
559 		return true;
560 
561 	ondev1 = bpf_offload_find_netdev(offload->netdev);
562 	ondev2 = bpf_offload_find_netdev(netdev);
563 
564 	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
565 }
566 
bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)567 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
568 {
569 	bool ret;
570 
571 	down_read(&bpf_devs_lock);
572 	ret = __bpf_offload_dev_match(prog, netdev);
573 	up_read(&bpf_devs_lock);
574 
575 	return ret;
576 }
577 EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
578 
bpf_offload_prog_map_match(struct bpf_prog * prog,struct bpf_map * map)579 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
580 {
581 	struct bpf_offloaded_map *offmap;
582 	bool ret;
583 
584 	if (!bpf_map_is_dev_bound(map))
585 		return bpf_map_offload_neutral(map);
586 	offmap = map_to_offmap(map);
587 
588 	down_read(&bpf_devs_lock);
589 	ret = __bpf_offload_dev_match(prog, offmap->netdev);
590 	up_read(&bpf_devs_lock);
591 
592 	return ret;
593 }
594 
bpf_offload_dev_netdev_register(struct bpf_offload_dev * offdev,struct net_device * netdev)595 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
596 				    struct net_device *netdev)
597 {
598 	struct bpf_offload_netdev *ondev;
599 	int err;
600 
601 	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
602 	if (!ondev)
603 		return -ENOMEM;
604 
605 	ondev->netdev = netdev;
606 	ondev->offdev = offdev;
607 	INIT_LIST_HEAD(&ondev->progs);
608 	INIT_LIST_HEAD(&ondev->maps);
609 
610 	down_write(&bpf_devs_lock);
611 	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
612 	if (err) {
613 		netdev_warn(netdev, "failed to register for BPF offload\n");
614 		goto err_unlock_free;
615 	}
616 
617 	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
618 	up_write(&bpf_devs_lock);
619 	return 0;
620 
621 err_unlock_free:
622 	up_write(&bpf_devs_lock);
623 	kfree(ondev);
624 	return err;
625 }
626 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
627 
bpf_offload_dev_netdev_unregister(struct bpf_offload_dev * offdev,struct net_device * netdev)628 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
629 				       struct net_device *netdev)
630 {
631 	struct bpf_offload_netdev *ondev, *altdev;
632 	struct bpf_offloaded_map *offmap, *mtmp;
633 	struct bpf_prog_offload *offload, *ptmp;
634 
635 	ASSERT_RTNL();
636 
637 	down_write(&bpf_devs_lock);
638 	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
639 	if (WARN_ON(!ondev))
640 		goto unlock;
641 
642 	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
643 	list_del(&ondev->offdev_netdevs);
644 
645 	/* Try to move the objects to another netdev of the device */
646 	altdev = list_first_entry_or_null(&offdev->netdevs,
647 					  struct bpf_offload_netdev,
648 					  offdev_netdevs);
649 	if (altdev) {
650 		list_for_each_entry(offload, &ondev->progs, offloads)
651 			offload->netdev = altdev->netdev;
652 		list_splice_init(&ondev->progs, &altdev->progs);
653 
654 		list_for_each_entry(offmap, &ondev->maps, offloads)
655 			offmap->netdev = altdev->netdev;
656 		list_splice_init(&ondev->maps, &altdev->maps);
657 	} else {
658 		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
659 			__bpf_prog_offload_destroy(offload->prog);
660 		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
661 			__bpf_map_offload_destroy(offmap);
662 	}
663 
664 	WARN_ON(!list_empty(&ondev->progs));
665 	WARN_ON(!list_empty(&ondev->maps));
666 	kfree(ondev);
667 unlock:
668 	up_write(&bpf_devs_lock);
669 }
670 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
671 
672 struct bpf_offload_dev *
bpf_offload_dev_create(const struct bpf_prog_offload_ops * ops,void * priv)673 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
674 {
675 	struct bpf_offload_dev *offdev;
676 	int err;
677 
678 	down_write(&bpf_devs_lock);
679 	if (!offdevs_inited) {
680 		err = rhashtable_init(&offdevs, &offdevs_params);
681 		if (err) {
682 			up_write(&bpf_devs_lock);
683 			return ERR_PTR(err);
684 		}
685 		offdevs_inited = true;
686 	}
687 	up_write(&bpf_devs_lock);
688 
689 	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
690 	if (!offdev)
691 		return ERR_PTR(-ENOMEM);
692 
693 	offdev->ops = ops;
694 	offdev->priv = priv;
695 	INIT_LIST_HEAD(&offdev->netdevs);
696 
697 	return offdev;
698 }
699 EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
700 
bpf_offload_dev_destroy(struct bpf_offload_dev * offdev)701 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
702 {
703 	WARN_ON(!list_empty(&offdev->netdevs));
704 	kfree(offdev);
705 }
706 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
707 
bpf_offload_dev_priv(struct bpf_offload_dev * offdev)708 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
709 {
710 	return offdev->priv;
711 }
712 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
713