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 */
34 static DECLARE_RWSEM(bpf_devs_lock);
35
36 struct bpf_offload_dev {
37 const struct bpf_prog_offload_ops *ops;
38 struct list_head netdevs;
39 void *priv;
40 };
41
42 struct 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
51 static 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
59 static struct rhashtable offdevs;
60
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 *
71 bpf_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
78 static 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
103 err_free:
104 kfree(ondev);
105 return err;
106 }
107
108 static 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
120 static 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
136 static 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
145 static 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
188 static 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;
223 err_free:
224 kfree(offload);
225 return err;
226 }
227
228 int 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 | BPF_F_XDP_HAS_FRAGS))
238 return -EINVAL;
239
240 /* Frags are allowed only if program is dev-bound-only, but not
241 * if it is requesting bpf offload.
242 */
243 if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS &&
244 !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY))
245 return -EINVAL;
246
247 if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS &&
248 attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)
249 return -EINVAL;
250
251 netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex);
252 if (!netdev)
253 return -EINVAL;
254
255 err = bpf_dev_offload_check(netdev);
256 if (err)
257 goto out;
258
259 prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY);
260
261 down_write(&bpf_devs_lock);
262 err = __bpf_prog_dev_bound_init(prog, netdev);
263 up_write(&bpf_devs_lock);
264
265 out:
266 dev_put(netdev);
267 return err;
268 }
269
270 int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog)
271 {
272 int err;
273
274 if (!bpf_prog_is_dev_bound(old_prog->aux))
275 return 0;
276
277 if (bpf_prog_is_offloaded(old_prog->aux))
278 return -EINVAL;
279
280 new_prog->aux->dev_bound = old_prog->aux->dev_bound;
281 new_prog->aux->offload_requested = old_prog->aux->offload_requested;
282
283 down_write(&bpf_devs_lock);
284 if (!old_prog->aux->offload) {
285 err = -EINVAL;
286 goto out;
287 }
288
289 err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev);
290
291 out:
292 up_write(&bpf_devs_lock);
293 return err;
294 }
295
296 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
297 {
298 struct bpf_prog_offload *offload;
299 int ret = -ENODEV;
300
301 down_read(&bpf_devs_lock);
302 offload = prog->aux->offload;
303 if (offload) {
304 ret = offload->offdev->ops->prepare(prog);
305 offload->dev_state = !ret;
306 }
307 up_read(&bpf_devs_lock);
308
309 return ret;
310 }
311
312 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
313 int insn_idx, int prev_insn_idx)
314 {
315 struct bpf_prog_offload *offload;
316 int ret = -ENODEV;
317
318 down_read(&bpf_devs_lock);
319 offload = env->prog->aux->offload;
320 if (offload)
321 ret = offload->offdev->ops->insn_hook(env, insn_idx,
322 prev_insn_idx);
323 up_read(&bpf_devs_lock);
324
325 return ret;
326 }
327
328 int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
329 {
330 struct bpf_prog_offload *offload;
331 int ret = -ENODEV;
332
333 down_read(&bpf_devs_lock);
334 offload = env->prog->aux->offload;
335 if (offload) {
336 if (offload->offdev->ops->finalize)
337 ret = offload->offdev->ops->finalize(env);
338 else
339 ret = 0;
340 }
341 up_read(&bpf_devs_lock);
342
343 return ret;
344 }
345
346 void
347 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
348 struct bpf_insn *insn)
349 {
350 const struct bpf_prog_offload_ops *ops;
351 struct bpf_prog_offload *offload;
352 int ret = -EOPNOTSUPP;
353
354 down_read(&bpf_devs_lock);
355 offload = env->prog->aux->offload;
356 if (offload) {
357 ops = offload->offdev->ops;
358 if (!offload->opt_failed && ops->replace_insn)
359 ret = ops->replace_insn(env, off, insn);
360 offload->opt_failed |= ret;
361 }
362 up_read(&bpf_devs_lock);
363 }
364
365 void
366 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
367 {
368 struct bpf_prog_offload *offload;
369 int ret = -EOPNOTSUPP;
370
371 down_read(&bpf_devs_lock);
372 offload = env->prog->aux->offload;
373 if (offload) {
374 if (!offload->opt_failed && offload->offdev->ops->remove_insns)
375 ret = offload->offdev->ops->remove_insns(env, off, cnt);
376 offload->opt_failed |= ret;
377 }
378 up_read(&bpf_devs_lock);
379 }
380
381 void bpf_prog_dev_bound_destroy(struct bpf_prog *prog)
382 {
383 struct bpf_offload_netdev *ondev;
384 struct net_device *netdev;
385
386 rtnl_lock();
387 down_write(&bpf_devs_lock);
388 if (prog->aux->offload) {
389 list_del_init(&prog->aux->offload->offloads);
390
391 netdev = prog->aux->offload->netdev;
392 __bpf_prog_offload_destroy(prog);
393
394 ondev = bpf_offload_find_netdev(netdev);
395 if (!ondev->offdev && list_empty(&ondev->progs))
396 __bpf_offload_dev_netdev_unregister(NULL, netdev);
397 }
398 up_write(&bpf_devs_lock);
399 rtnl_unlock();
400 }
401
402 static int bpf_prog_offload_translate(struct bpf_prog *prog)
403 {
404 struct bpf_prog_offload *offload;
405 int ret = -ENODEV;
406
407 down_read(&bpf_devs_lock);
408 offload = prog->aux->offload;
409 if (offload)
410 ret = offload->offdev->ops->translate(prog);
411 up_read(&bpf_devs_lock);
412
413 return ret;
414 }
415
416 static unsigned int bpf_prog_warn_on_exec(const void *ctx,
417 const struct bpf_insn *insn)
418 {
419 WARN(1, "attempt to execute device eBPF program on the host!");
420 return 0;
421 }
422
423 int bpf_prog_offload_compile(struct bpf_prog *prog)
424 {
425 prog->bpf_func = bpf_prog_warn_on_exec;
426
427 return bpf_prog_offload_translate(prog);
428 }
429
430 struct ns_get_path_bpf_prog_args {
431 struct bpf_prog *prog;
432 struct bpf_prog_info *info;
433 };
434
435 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
436 {
437 struct ns_get_path_bpf_prog_args *args = private_data;
438 struct bpf_prog_aux *aux = args->prog->aux;
439 struct ns_common *ns;
440 struct net *net;
441
442 rtnl_lock();
443 down_read(&bpf_devs_lock);
444
445 if (aux->offload) {
446 args->info->ifindex = aux->offload->netdev->ifindex;
447 net = dev_net(aux->offload->netdev);
448 get_net(net);
449 ns = &net->ns;
450 } else {
451 args->info->ifindex = 0;
452 ns = NULL;
453 }
454
455 up_read(&bpf_devs_lock);
456 rtnl_unlock();
457
458 return ns;
459 }
460
461 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
462 struct bpf_prog *prog)
463 {
464 struct ns_get_path_bpf_prog_args args = {
465 .prog = prog,
466 .info = info,
467 };
468 struct bpf_prog_aux *aux = prog->aux;
469 struct inode *ns_inode;
470 struct path ns_path;
471 char __user *uinsns;
472 int res;
473 u32 ulen;
474
475 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
476 if (res) {
477 if (!info->ifindex)
478 return -ENODEV;
479 return res;
480 }
481
482 down_read(&bpf_devs_lock);
483
484 if (!aux->offload) {
485 up_read(&bpf_devs_lock);
486 return -ENODEV;
487 }
488
489 ulen = info->jited_prog_len;
490 info->jited_prog_len = aux->offload->jited_len;
491 if (info->jited_prog_len && ulen) {
492 uinsns = u64_to_user_ptr(info->jited_prog_insns);
493 ulen = min_t(u32, info->jited_prog_len, ulen);
494 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
495 up_read(&bpf_devs_lock);
496 return -EFAULT;
497 }
498 }
499
500 up_read(&bpf_devs_lock);
501
502 ns_inode = ns_path.dentry->d_inode;
503 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
504 info->netns_ino = ns_inode->i_ino;
505 path_put(&ns_path);
506
507 return 0;
508 }
509
510 const struct bpf_prog_ops bpf_offload_prog_ops = {
511 };
512
513 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
514 {
515 struct net *net = current->nsproxy->net_ns;
516 struct bpf_offload_netdev *ondev;
517 struct bpf_offloaded_map *offmap;
518 int err;
519
520 if (!capable(CAP_SYS_ADMIN))
521 return ERR_PTR(-EPERM);
522 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
523 attr->map_type != BPF_MAP_TYPE_HASH)
524 return ERR_PTR(-EINVAL);
525
526 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE);
527 if (!offmap)
528 return ERR_PTR(-ENOMEM);
529
530 bpf_map_init_from_attr(&offmap->map, attr);
531
532 rtnl_lock();
533 down_write(&bpf_devs_lock);
534 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
535 err = bpf_dev_offload_check(offmap->netdev);
536 if (err)
537 goto err_unlock;
538
539 ondev = bpf_offload_find_netdev(offmap->netdev);
540 if (!ondev) {
541 err = -EINVAL;
542 goto err_unlock;
543 }
544
545 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
546 if (err)
547 goto err_unlock;
548
549 list_add_tail(&offmap->offloads, &ondev->maps);
550 up_write(&bpf_devs_lock);
551 rtnl_unlock();
552
553 return &offmap->map;
554
555 err_unlock:
556 up_write(&bpf_devs_lock);
557 rtnl_unlock();
558 bpf_map_area_free(offmap);
559 return ERR_PTR(err);
560 }
561
562 void bpf_map_offload_map_free(struct bpf_map *map)
563 {
564 struct bpf_offloaded_map *offmap = map_to_offmap(map);
565
566 rtnl_lock();
567 down_write(&bpf_devs_lock);
568 if (offmap->netdev)
569 __bpf_map_offload_destroy(offmap);
570 up_write(&bpf_devs_lock);
571 rtnl_unlock();
572
573 bpf_map_area_free(offmap);
574 }
575
576 u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
577 {
578 /* The memory dynamically allocated in netdev dev_ops is not counted */
579 return sizeof(struct bpf_offloaded_map);
580 }
581
582 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
583 {
584 struct bpf_offloaded_map *offmap = map_to_offmap(map);
585 int ret = -ENODEV;
586
587 down_read(&bpf_devs_lock);
588 if (offmap->netdev)
589 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
590 up_read(&bpf_devs_lock);
591
592 return ret;
593 }
594
595 int bpf_map_offload_update_elem(struct bpf_map *map,
596 void *key, void *value, u64 flags)
597 {
598 struct bpf_offloaded_map *offmap = map_to_offmap(map);
599 int ret = -ENODEV;
600
601 if (unlikely(flags > BPF_EXIST))
602 return -EINVAL;
603
604 down_read(&bpf_devs_lock);
605 if (offmap->netdev)
606 ret = offmap->dev_ops->map_update_elem(offmap, key, value,
607 flags);
608 up_read(&bpf_devs_lock);
609
610 return ret;
611 }
612
613 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
614 {
615 struct bpf_offloaded_map *offmap = map_to_offmap(map);
616 int ret = -ENODEV;
617
618 down_read(&bpf_devs_lock);
619 if (offmap->netdev)
620 ret = offmap->dev_ops->map_delete_elem(offmap, key);
621 up_read(&bpf_devs_lock);
622
623 return ret;
624 }
625
626 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
627 {
628 struct bpf_offloaded_map *offmap = map_to_offmap(map);
629 int ret = -ENODEV;
630
631 down_read(&bpf_devs_lock);
632 if (offmap->netdev)
633 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
634 up_read(&bpf_devs_lock);
635
636 return ret;
637 }
638
639 struct ns_get_path_bpf_map_args {
640 struct bpf_offloaded_map *offmap;
641 struct bpf_map_info *info;
642 };
643
644 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
645 {
646 struct ns_get_path_bpf_map_args *args = private_data;
647 struct ns_common *ns;
648 struct net *net;
649
650 rtnl_lock();
651 down_read(&bpf_devs_lock);
652
653 if (args->offmap->netdev) {
654 args->info->ifindex = args->offmap->netdev->ifindex;
655 net = dev_net(args->offmap->netdev);
656 get_net(net);
657 ns = &net->ns;
658 } else {
659 args->info->ifindex = 0;
660 ns = NULL;
661 }
662
663 up_read(&bpf_devs_lock);
664 rtnl_unlock();
665
666 return ns;
667 }
668
669 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
670 {
671 struct ns_get_path_bpf_map_args args = {
672 .offmap = map_to_offmap(map),
673 .info = info,
674 };
675 struct inode *ns_inode;
676 struct path ns_path;
677 int res;
678
679 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
680 if (res) {
681 if (!info->ifindex)
682 return -ENODEV;
683 return res;
684 }
685
686 ns_inode = ns_path.dentry->d_inode;
687 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
688 info->netns_ino = ns_inode->i_ino;
689 path_put(&ns_path);
690
691 return 0;
692 }
693
694 static bool __bpf_offload_dev_match(struct bpf_prog *prog,
695 struct net_device *netdev)
696 {
697 struct bpf_offload_netdev *ondev1, *ondev2;
698 struct bpf_prog_offload *offload;
699
700 if (!bpf_prog_is_dev_bound(prog->aux))
701 return false;
702
703 offload = prog->aux->offload;
704 if (!offload)
705 return false;
706 if (offload->netdev == netdev)
707 return true;
708
709 ondev1 = bpf_offload_find_netdev(offload->netdev);
710 ondev2 = bpf_offload_find_netdev(netdev);
711
712 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
713 }
714
715 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
716 {
717 bool ret;
718
719 down_read(&bpf_devs_lock);
720 ret = __bpf_offload_dev_match(prog, netdev);
721 up_read(&bpf_devs_lock);
722
723 return ret;
724 }
725 EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
726
727 bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs)
728 {
729 bool ret;
730
731 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux))
732 return false;
733
734 down_read(&bpf_devs_lock);
735 ret = lhs->aux->offload && rhs->aux->offload &&
736 lhs->aux->offload->netdev &&
737 lhs->aux->offload->netdev == rhs->aux->offload->netdev;
738 up_read(&bpf_devs_lock);
739
740 return ret;
741 }
742
743 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
744 {
745 struct bpf_offloaded_map *offmap;
746 bool ret;
747
748 if (!bpf_map_is_offloaded(map))
749 return bpf_map_offload_neutral(map);
750 offmap = map_to_offmap(map);
751
752 down_read(&bpf_devs_lock);
753 ret = __bpf_offload_dev_match(prog, offmap->netdev);
754 up_read(&bpf_devs_lock);
755
756 return ret;
757 }
758
759 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
760 struct net_device *netdev)
761 {
762 int err;
763
764 down_write(&bpf_devs_lock);
765 err = __bpf_offload_dev_netdev_register(offdev, netdev);
766 up_write(&bpf_devs_lock);
767 return err;
768 }
769 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
770
771 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
772 struct net_device *netdev)
773 {
774 down_write(&bpf_devs_lock);
775 __bpf_offload_dev_netdev_unregister(offdev, netdev);
776 up_write(&bpf_devs_lock);
777 }
778 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
779
780 struct bpf_offload_dev *
781 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
782 {
783 struct bpf_offload_dev *offdev;
784
785 offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
786 if (!offdev)
787 return ERR_PTR(-ENOMEM);
788
789 offdev->ops = ops;
790 offdev->priv = priv;
791 INIT_LIST_HEAD(&offdev->netdevs);
792
793 return offdev;
794 }
795 EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
796
797 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
798 {
799 WARN_ON(!list_empty(&offdev->netdevs));
800 kfree(offdev);
801 }
802 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
803
804 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
805 {
806 return offdev->priv;
807 }
808 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
809
810 void bpf_dev_bound_netdev_unregister(struct net_device *dev)
811 {
812 struct bpf_offload_netdev *ondev;
813
814 ASSERT_RTNL();
815
816 down_write(&bpf_devs_lock);
817 ondev = bpf_offload_find_netdev(dev);
818 if (ondev && !ondev->offdev)
819 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev);
820 up_write(&bpf_devs_lock);
821 }
822
823 int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log,
824 struct bpf_prog_aux *prog_aux)
825 {
826 if (!bpf_prog_is_dev_bound(prog_aux)) {
827 bpf_log(log, "metadata kfuncs require device-bound program\n");
828 return -EINVAL;
829 }
830
831 if (bpf_prog_is_offloaded(prog_aux)) {
832 bpf_log(log, "metadata kfuncs can't be offloaded\n");
833 return -EINVAL;
834 }
835
836 return 0;
837 }
838
839 void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
840 {
841 const struct xdp_metadata_ops *ops;
842 void *p = NULL;
843
844 /* We don't hold bpf_devs_lock while resolving several
845 * kfuncs and can race with the unregister_netdevice().
846 * We rely on bpf_dev_bound_match() check at attach
847 * to render this program unusable.
848 */
849 down_read(&bpf_devs_lock);
850 if (!prog->aux->offload)
851 goto out;
852
853 ops = prog->aux->offload->netdev->xdp_metadata_ops;
854 if (!ops)
855 goto out;
856
857 #define XDP_METADATA_KFUNC(name, _, __, xmo) \
858 if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
859 XDP_METADATA_KFUNC_xxx
860 #undef XDP_METADATA_KFUNC
861
862 out:
863 up_read(&bpf_devs_lock);
864
865 return p;
866 }
867
868 static int __init bpf_offload_init(void)
869 {
870 return rhashtable_init(&offdevs, &offdevs_params);
871 }
872
873 core_initcall(bpf_offload_init);
874
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