projects/linux·blob v6.6 · refs

865 lines · 20.0 KiB

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