offload.c

  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#include <net/netdev_lock.h>
 29#include <net/xdp.h>
 30
 31/* Protects offdevs, members of bpf_offload_netdev and offload members
 32 * of all progs.
 33 * RTNL lock cannot be taken when holding this lock.
 34 */
 35static DECLARE_RWSEM(bpf_devs_lock);
 36
 37struct bpf_offload_dev {
 38	const struct bpf_prog_offload_ops *ops;
 39	struct list_head netdevs;
 40	void *priv;
 41};
 42
 43struct bpf_offload_netdev {
 44	struct rhash_head l;
 45	struct net_device *netdev;
 46	struct bpf_offload_dev *offdev; /* NULL when bound-only */
 47	struct list_head progs;
 48	struct list_head maps;
 49	struct list_head offdev_netdevs;
 50};
 51
 52static const struct rhashtable_params offdevs_params = {
 53	.nelem_hint		= 4,
 54	.key_len		= sizeof(struct net_device *),
 55	.key_offset		= offsetof(struct bpf_offload_netdev, netdev),
 56	.head_offset		= offsetof(struct bpf_offload_netdev, l),
 57	.automatic_shrinking	= true,
 58};
 59
 60static struct rhashtable offdevs;
 61
 62static int bpf_dev_offload_check(struct net_device *netdev)
 63{
 64	if (!netdev)
 65		return -EINVAL;
 66	if (!netdev->netdev_ops->ndo_bpf)
 67		return -EOPNOTSUPP;
 68	return 0;
 69}
 70
 71static struct bpf_offload_netdev *
 72bpf_offload_find_netdev(struct net_device *netdev)
 73{
 74	lockdep_assert_held(&bpf_devs_lock);
 75
 76	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
 77}
 78
 79static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
 80					     struct net_device *netdev)
 81{
 82	struct bpf_offload_netdev *ondev;
 83	int err;
 84
 85	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
 86	if (!ondev)
 87		return -ENOMEM;
 88
 89	ondev->netdev = netdev;
 90	ondev->offdev = offdev;
 91	INIT_LIST_HEAD(&ondev->progs);
 92	INIT_LIST_HEAD(&ondev->maps);
 93
 94	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
 95	if (err) {
 96		netdev_warn(netdev, "failed to register for BPF offload\n");
 97		goto err_free;
 98	}
 99
100	if (offdev)
101		list_add(&ondev->offdev_netdevs, &offdev->netdevs);
102	return 0;
103
104err_free:
105	kfree(ondev);
106	return err;
107}
108
109static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
110{
111	struct bpf_prog_offload *offload = prog->aux->offload;
112
113	if (offload->dev_state)
114		offload->offdev->ops->destroy(prog);
115
116	list_del_init(&offload->offloads);
117	kfree(offload);
118	prog->aux->offload = NULL;
119}
120
121static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
122			       enum bpf_netdev_command cmd)
123{
124	struct netdev_bpf data = {};
125	struct net_device *netdev;
126
127	ASSERT_RTNL();
128
129	data.command = cmd;
130	data.offmap = offmap;
131	/* Caller must make sure netdev is valid */
132	netdev = offmap->netdev;
133
134	return netdev->netdev_ops->ndo_bpf(netdev, &data);
135}
136
137static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
138{
139	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
140	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
141	bpf_map_free_id(&offmap->map);
142	list_del_init(&offmap->offloads);
143	offmap->netdev = NULL;
144}
145
146static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
147						struct net_device *netdev)
148{
149	struct bpf_offload_netdev *ondev, *altdev = NULL;
150	struct bpf_offloaded_map *offmap, *mtmp;
151	struct bpf_prog_offload *offload, *ptmp;
152
153	ASSERT_RTNL();
154
155	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
156	if (WARN_ON(!ondev))
157		return;
158
159	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
160
161	/* Try to move the objects to another netdev of the device */
162	if (offdev) {
163		list_del(&ondev->offdev_netdevs);
164		altdev = list_first_entry_or_null(&offdev->netdevs,
165						  struct bpf_offload_netdev,
166						  offdev_netdevs);
167	}
168
169	if (altdev) {
170		list_for_each_entry(offload, &ondev->progs, offloads)
171			offload->netdev = altdev->netdev;
172		list_splice_init(&ondev->progs, &altdev->progs);
173
174		list_for_each_entry(offmap, &ondev->maps, offloads)
175			offmap->netdev = altdev->netdev;
176		list_splice_init(&ondev->maps, &altdev->maps);
177	} else {
178		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
179			__bpf_prog_offload_destroy(offload->prog);
180		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
181			__bpf_map_offload_destroy(offmap);
182	}
183
184	WARN_ON(!list_empty(&ondev->progs));
185	WARN_ON(!list_empty(&ondev->maps));
186	kfree(ondev);
187}
188
189static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *netdev)
190{
191	struct bpf_offload_netdev *ondev;
192	struct bpf_prog_offload *offload;
193	int err;
194
195	offload = kzalloc(sizeof(*offload), GFP_USER);
196	if (!offload)
197		return -ENOMEM;
198
199	offload->prog = prog;
200	offload->netdev = netdev;
201
202	ondev = bpf_offload_find_netdev(offload->netdev);
203	/* When program is offloaded require presence of "true"
204	 * bpf_offload_netdev, avoid the one created for !ondev case below.
205	 */
206	if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) {
207		err = -EINVAL;
208		goto err_free;
209	}
210	if (!ondev) {
211		/* When only binding to the device, explicitly
212		 * create an entry in the hashtable.
213		 */
214		err = __bpf_offload_dev_netdev_register(NULL, offload->netdev);
215		if (err)
216			goto err_free;
217		ondev = bpf_offload_find_netdev(offload->netdev);
218	}
219	offload->offdev = ondev->offdev;
220	prog->aux->offload = offload;
221	list_add_tail(&offload->offloads, &ondev->progs);
222
223	return 0;
224err_free:
225	kfree(offload);
226	return err;
227}
228
229int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr)
230{
231	struct net_device *netdev;
232	int err;
233
234	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
235	    attr->prog_type != BPF_PROG_TYPE_XDP)
236		return -EINVAL;
237
238	if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS))
239		return -EINVAL;
240
241	/* Frags are allowed only if program is dev-bound-only, but not
242	 * if it is requesting bpf offload.
243	 */
244	if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS &&
245	    !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY))
246		return -EINVAL;
247
248	if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS &&
249	    attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)
250		return -EINVAL;
251
252	netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex);
253	if (!netdev)
254		return -EINVAL;
255
256	err = bpf_dev_offload_check(netdev);
257	if (err)
258		goto out;
259
260	prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY);
261
262	down_write(&bpf_devs_lock);
263	err = __bpf_prog_dev_bound_init(prog, netdev);
264	up_write(&bpf_devs_lock);
265
266out:
267	dev_put(netdev);
268	return err;
269}
270
271int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog)
272{
273	int err;
274
275	if (!bpf_prog_is_dev_bound(old_prog->aux))
276		return 0;
277
278	if (bpf_prog_is_offloaded(old_prog->aux))
279		return -EINVAL;
280
281	new_prog->aux->dev_bound = old_prog->aux->dev_bound;
282	new_prog->aux->offload_requested = old_prog->aux->offload_requested;
283
284	down_write(&bpf_devs_lock);
285	if (!old_prog->aux->offload) {
286		err = -EINVAL;
287		goto out;
288	}
289
290	err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev);
291
292out:
293	up_write(&bpf_devs_lock);
294	return err;
295}
296
297int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
298{
299	struct bpf_prog_offload *offload;
300	int ret = -ENODEV;
301
302	down_read(&bpf_devs_lock);
303	offload = prog->aux->offload;
304	if (offload) {
305		ret = offload->offdev->ops->prepare(prog);
306		offload->dev_state = !ret;
307	}
308	up_read(&bpf_devs_lock);
309
310	return ret;
311}
312
313int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
314				 int insn_idx, int prev_insn_idx)
315{
316	struct bpf_prog_offload *offload;
317	int ret = -ENODEV;
318
319	down_read(&bpf_devs_lock);
320	offload = env->prog->aux->offload;
321	if (offload)
322		ret = offload->offdev->ops->insn_hook(env, insn_idx,
323						      prev_insn_idx);
324	up_read(&bpf_devs_lock);
325
326	return ret;
327}
328
329int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
330{
331	struct bpf_prog_offload *offload;
332	int ret = -ENODEV;
333
334	down_read(&bpf_devs_lock);
335	offload = env->prog->aux->offload;
336	if (offload) {
337		if (offload->offdev->ops->finalize)
338			ret = offload->offdev->ops->finalize(env);
339		else
340			ret = 0;
341	}
342	up_read(&bpf_devs_lock);
343
344	return ret;
345}
346
347void
348bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
349			      struct bpf_insn *insn)
350{
351	const struct bpf_prog_offload_ops *ops;
352	struct bpf_prog_offload *offload;
353	int ret = -EOPNOTSUPP;
354
355	down_read(&bpf_devs_lock);
356	offload = env->prog->aux->offload;
357	if (offload) {
358		ops = offload->offdev->ops;
359		if (!offload->opt_failed && ops->replace_insn)
360			ret = ops->replace_insn(env, off, insn);
361		offload->opt_failed |= ret;
362	}
363	up_read(&bpf_devs_lock);
364}
365
366void
367bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
368{
369	struct bpf_prog_offload *offload;
370	int ret = -EOPNOTSUPP;
371
372	down_read(&bpf_devs_lock);
373	offload = env->prog->aux->offload;
374	if (offload) {
375		if (!offload->opt_failed && offload->offdev->ops->remove_insns)
376			ret = offload->offdev->ops->remove_insns(env, off, cnt);
377		offload->opt_failed |= ret;
378	}
379	up_read(&bpf_devs_lock);
380}
381
382void bpf_prog_dev_bound_destroy(struct bpf_prog *prog)
383{
384	struct bpf_offload_netdev *ondev;
385	struct net_device *netdev;
386
387	rtnl_lock();
388	down_write(&bpf_devs_lock);
389	if (prog->aux->offload) {
390		list_del_init(&prog->aux->offload->offloads);
391
392		netdev = prog->aux->offload->netdev;
393		__bpf_prog_offload_destroy(prog);
394
395		ondev = bpf_offload_find_netdev(netdev);
396		if (!ondev->offdev && list_empty(&ondev->progs))
397			__bpf_offload_dev_netdev_unregister(NULL, netdev);
398	}
399	up_write(&bpf_devs_lock);
400	rtnl_unlock();
401}
402
403static int bpf_prog_offload_translate(struct bpf_prog *prog)
404{
405	struct bpf_prog_offload *offload;
406	int ret = -ENODEV;
407
408	down_read(&bpf_devs_lock);
409	offload = prog->aux->offload;
410	if (offload)
411		ret = offload->offdev->ops->translate(prog);
412	up_read(&bpf_devs_lock);
413
414	return ret;
415}
416
417static unsigned int bpf_prog_warn_on_exec(const void *ctx,
418					  const struct bpf_insn *insn)
419{
420	WARN(1, "attempt to execute device eBPF program on the host!");
421	return 0;
422}
423
424int bpf_prog_offload_compile(struct bpf_prog *prog)
425{
426	prog->bpf_func = bpf_prog_warn_on_exec;
427
428	return bpf_prog_offload_translate(prog);
429}
430
431struct ns_get_path_bpf_prog_args {
432	struct bpf_prog *prog;
433	struct bpf_prog_info *info;
434};
435
436static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
437{
438	struct ns_get_path_bpf_prog_args *args = private_data;
439	struct bpf_prog_aux *aux = args->prog->aux;
440	struct ns_common *ns;
441	struct net *net;
442
443	rtnl_lock();
444	down_read(&bpf_devs_lock);
445
446	if (aux->offload) {
447		args->info->ifindex = aux->offload->netdev->ifindex;
448		net = dev_net(aux->offload->netdev);
449		get_net(net);
450		ns = &net->ns;
451	} else {
452		args->info->ifindex = 0;
453		ns = NULL;
454	}
455
456	up_read(&bpf_devs_lock);
457	rtnl_unlock();
458
459	return ns;
460}
461
462int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
463			       struct bpf_prog *prog)
464{
465	struct ns_get_path_bpf_prog_args args = {
466		.prog	= prog,
467		.info	= info,
468	};
469	struct bpf_prog_aux *aux = prog->aux;
470	struct inode *ns_inode;
471	struct path ns_path;
472	char __user *uinsns;
473	int res;
474	u32 ulen;
475
476	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
477	if (res) {
478		if (!info->ifindex)
479			return -ENODEV;
480		return res;
481	}
482
483	down_read(&bpf_devs_lock);
484
485	if (!aux->offload) {
486		up_read(&bpf_devs_lock);
487		return -ENODEV;
488	}
489
490	ulen = info->jited_prog_len;
491	info->jited_prog_len = aux->offload->jited_len;
492	if (info->jited_prog_len && ulen) {
493		uinsns = u64_to_user_ptr(info->jited_prog_insns);
494		ulen = min_t(u32, info->jited_prog_len, ulen);
495		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
496			up_read(&bpf_devs_lock);
497			return -EFAULT;
498		}
499	}
500
501	up_read(&bpf_devs_lock);
502
503	ns_inode = ns_path.dentry->d_inode;
504	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
505	info->netns_ino = ns_inode->i_ino;
506	path_put(&ns_path);
507
508	return 0;
509}
510
511const struct bpf_prog_ops bpf_offload_prog_ops = {
512};
513
514struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
515{
516	struct net *net = current->nsproxy->net_ns;
517	struct bpf_offload_netdev *ondev;
518	struct bpf_offloaded_map *offmap;
519	int err;
520
521	if (!capable(CAP_SYS_ADMIN))
522		return ERR_PTR(-EPERM);
523	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
524	    attr->map_type != BPF_MAP_TYPE_HASH)
525		return ERR_PTR(-EINVAL);
526
527	offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE);
528	if (!offmap)
529		return ERR_PTR(-ENOMEM);
530
531	bpf_map_init_from_attr(&offmap->map, attr);
532	rtnl_lock();
533	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
534	err = bpf_dev_offload_check(offmap->netdev);
535	if (err)
536		goto err_unlock_rtnl;
537
538	netdev_lock_ops(offmap->netdev);
539	down_write(&bpf_devs_lock);
540
541	ondev = bpf_offload_find_netdev(offmap->netdev);
542	if (!ondev) {
543		err = -EINVAL;
544		goto err_unlock;
545	}
546
547	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
548	if (err)
549		goto err_unlock;
550
551	list_add_tail(&offmap->offloads, &ondev->maps);
552	up_write(&bpf_devs_lock);
553	netdev_unlock_ops(offmap->netdev);
554	rtnl_unlock();
555
556	return &offmap->map;
557
558err_unlock:
559	up_write(&bpf_devs_lock);
560	netdev_unlock_ops(offmap->netdev);
561err_unlock_rtnl:
562	rtnl_unlock();
563	bpf_map_area_free(offmap);
564	return ERR_PTR(err);
565}
566
567void bpf_map_offload_map_free(struct bpf_map *map)
568{
569	struct bpf_offloaded_map *offmap = map_to_offmap(map);
570
571	rtnl_lock();
572	down_write(&bpf_devs_lock);
573	if (offmap->netdev)
574		__bpf_map_offload_destroy(offmap);
575	up_write(&bpf_devs_lock);
576	rtnl_unlock();
577
578	bpf_map_area_free(offmap);
579}
580
581u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
582{
583	/* The memory dynamically allocated in netdev dev_ops is not counted */
584	return sizeof(struct bpf_offloaded_map);
585}
586
587int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
588{
589	struct bpf_offloaded_map *offmap = map_to_offmap(map);
590	int ret = -ENODEV;
591
592	down_read(&bpf_devs_lock);
593	if (offmap->netdev)
594		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
595	up_read(&bpf_devs_lock);
596
597	return ret;
598}
599
600int bpf_map_offload_update_elem(struct bpf_map *map,
601				void *key, void *value, u64 flags)
602{
603	struct bpf_offloaded_map *offmap = map_to_offmap(map);
604	int ret = -ENODEV;
605
606	if (unlikely(flags > BPF_EXIST))
607		return -EINVAL;
608
609	down_read(&bpf_devs_lock);
610	if (offmap->netdev)
611		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
612						       flags);
613	up_read(&bpf_devs_lock);
614
615	return ret;
616}
617
618int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
619{
620	struct bpf_offloaded_map *offmap = map_to_offmap(map);
621	int ret = -ENODEV;
622
623	down_read(&bpf_devs_lock);
624	if (offmap->netdev)
625		ret = offmap->dev_ops->map_delete_elem(offmap, key);
626	up_read(&bpf_devs_lock);
627
628	return ret;
629}
630
631int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
632{
633	struct bpf_offloaded_map *offmap = map_to_offmap(map);
634	int ret = -ENODEV;
635
636	down_read(&bpf_devs_lock);
637	if (offmap->netdev)
638		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
639	up_read(&bpf_devs_lock);
640
641	return ret;
642}
643
644struct ns_get_path_bpf_map_args {
645	struct bpf_offloaded_map *offmap;
646	struct bpf_map_info *info;
647};
648
649static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
650{
651	struct ns_get_path_bpf_map_args *args = private_data;
652	struct ns_common *ns;
653	struct net *net;
654
655	rtnl_lock();
656	down_read(&bpf_devs_lock);
657
658	if (args->offmap->netdev) {
659		args->info->ifindex = args->offmap->netdev->ifindex;
660		net = dev_net(args->offmap->netdev);
661		get_net(net);
662		ns = &net->ns;
663	} else {
664		args->info->ifindex = 0;
665		ns = NULL;
666	}
667
668	up_read(&bpf_devs_lock);
669	rtnl_unlock();
670
671	return ns;
672}
673
674int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
675{
676	struct ns_get_path_bpf_map_args args = {
677		.offmap	= map_to_offmap(map),
678		.info	= info,
679	};
680	struct inode *ns_inode;
681	struct path ns_path;
682	int res;
683
684	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
685	if (res) {
686		if (!info->ifindex)
687			return -ENODEV;
688		return res;
689	}
690
691	ns_inode = ns_path.dentry->d_inode;
692	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
693	info->netns_ino = ns_inode->i_ino;
694	path_put(&ns_path);
695
696	return 0;
697}
698
699static bool __bpf_offload_dev_match(struct bpf_prog *prog,
700				    struct net_device *netdev)
701{
702	struct bpf_offload_netdev *ondev1, *ondev2;
703	struct bpf_prog_offload *offload;
704
705	if (!bpf_prog_is_dev_bound(prog->aux))
706		return false;
707
708	offload = prog->aux->offload;
709	if (!offload)
710		return false;
711	if (offload->netdev == netdev)
712		return true;
713
714	ondev1 = bpf_offload_find_netdev(offload->netdev);
715	ondev2 = bpf_offload_find_netdev(netdev);
716
717	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
718}
719
720bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
721{
722	bool ret;
723
724	down_read(&bpf_devs_lock);
725	ret = __bpf_offload_dev_match(prog, netdev);
726	up_read(&bpf_devs_lock);
727
728	return ret;
729}
730EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
731
732bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs)
733{
734	bool ret;
735
736	if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux))
737		return false;
738
739	down_read(&bpf_devs_lock);
740	ret = lhs->aux->offload && rhs->aux->offload &&
741	      lhs->aux->offload->netdev &&
742	      lhs->aux->offload->netdev == rhs->aux->offload->netdev;
743	up_read(&bpf_devs_lock);
744
745	return ret;
746}
747
748bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
749{
750	struct bpf_offloaded_map *offmap;
751	bool ret;
752
753	if (!bpf_map_is_offloaded(map))
754		return bpf_map_offload_neutral(map);
755	offmap = map_to_offmap(map);
756
757	down_read(&bpf_devs_lock);
758	ret = __bpf_offload_dev_match(prog, offmap->netdev);
759	up_read(&bpf_devs_lock);
760
761	return ret;
762}
763
764int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
765				    struct net_device *netdev)
766{
767	int err;
768
769	down_write(&bpf_devs_lock);
770	err = __bpf_offload_dev_netdev_register(offdev, netdev);
771	up_write(&bpf_devs_lock);
772	return err;
773}
774EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
775
776void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
777				       struct net_device *netdev)
778{
779	down_write(&bpf_devs_lock);
780	__bpf_offload_dev_netdev_unregister(offdev, netdev);
781	up_write(&bpf_devs_lock);
782}
783EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
784
785struct bpf_offload_dev *
786bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
787{
788	struct bpf_offload_dev *offdev;
789
790	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
791	if (!offdev)
792		return ERR_PTR(-ENOMEM);
793
794	offdev->ops = ops;
795	offdev->priv = priv;
796	INIT_LIST_HEAD(&offdev->netdevs);
797
798	return offdev;
799}
800EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
801
802void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
803{
804	WARN_ON(!list_empty(&offdev->netdevs));
805	kfree(offdev);
806}
807EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
808
809void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
810{
811	return offdev->priv;
812}
813EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
814
815void bpf_dev_bound_netdev_unregister(struct net_device *dev)
816{
817	struct bpf_offload_netdev *ondev;
818
819	ASSERT_RTNL();
820
821	down_write(&bpf_devs_lock);
822	ondev = bpf_offload_find_netdev(dev);
823	if (ondev && !ondev->offdev)
824		__bpf_offload_dev_netdev_unregister(NULL, ondev->netdev);
825	up_write(&bpf_devs_lock);
826}
827
828int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log,
829			      struct bpf_prog_aux *prog_aux)
830{
831	if (!bpf_prog_is_dev_bound(prog_aux)) {
832		bpf_log(log, "metadata kfuncs require device-bound program\n");
833		return -EINVAL;
834	}
835
836	if (bpf_prog_is_offloaded(prog_aux)) {
837		bpf_log(log, "metadata kfuncs can't be offloaded\n");
838		return -EINVAL;
839	}
840
841	return 0;
842}
843
844void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
845{
846	const struct xdp_metadata_ops *ops;
847	void *p = NULL;
848
849	/* We don't hold bpf_devs_lock while resolving several
850	 * kfuncs and can race with the unregister_netdevice().
851	 * We rely on bpf_dev_bound_match() check at attach
852	 * to render this program unusable.
853	 */
854	down_read(&bpf_devs_lock);
855	if (!prog->aux->offload)
856		goto out;
857
858	ops = prog->aux->offload->netdev->xdp_metadata_ops;
859	if (!ops)
860		goto out;
861
862#define XDP_METADATA_KFUNC(name, _, __, xmo) \
863	if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
864	XDP_METADATA_KFUNC_xxx
865#undef XDP_METADATA_KFUNC
866
867out:
868	up_read(&bpf_devs_lock);
869
870	return p;
871}
872
873static int __init bpf_offload_init(void)
874{
875	return rhashtable_init(&offdevs, &offdevs_params);
876}
877
878core_initcall(bpf_offload_init);