1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2017-2018 Netronome Systems, Inc.
4 */
5
6 #include <linux/bpf.h>
7 #include <linux/bpf_verifier.h>
8 #include <linux/bug.h>
9 #include <linux/kdev_t.h>
10 #include <linux/list.h>
11 #include <linux/lockdep.h>
12 #include <linux/netdevice.h>
13 #include <linux/printk.h>
14 #include <linux/proc_ns.h>
15 #include <linux/rhashtable.h>
16 #include <linux/rtnetlink.h>
17 #include <linux/rwsem.h>
18 #include <net/netdev_lock.h>
19 #include <net/xdp.h>
20
21 /* Protects offdevs, members of bpf_offload_netdev and offload members
22 * of all progs.
23 * RTNL lock cannot be taken when holding this lock.
24 */
25 static DECLARE_RWSEM(bpf_devs_lock);
26
27 struct bpf_offload_dev {
28 const struct bpf_prog_offload_ops *ops;
29 struct list_head netdevs;
30 void *priv;
31 };
32
33 struct bpf_offload_netdev {
34 struct rhash_head l;
35 struct net_device *netdev;
36 struct bpf_offload_dev *offdev; /* NULL when bound-only */
37 struct list_head progs;
38 struct list_head maps;
39 struct list_head offdev_netdevs;
40 };
41
42 static const struct rhashtable_params offdevs_params = {
43 .nelem_hint = 4,
44 .key_len = sizeof(struct net_device *),
45 .key_offset = offsetof(struct bpf_offload_netdev, netdev),
46 .head_offset = offsetof(struct bpf_offload_netdev, l),
47 .automatic_shrinking = true,
48 };
49
50 static struct rhashtable offdevs;
51
bpf_dev_offload_check(struct net_device * netdev)52 static int bpf_dev_offload_check(struct net_device *netdev)
53 {
54 if (!netdev)
55 return -EINVAL;
56 if (!netdev->netdev_ops->ndo_bpf)
57 return -EOPNOTSUPP;
58 return 0;
59 }
60
61 static struct bpf_offload_netdev *
bpf_offload_find_netdev(struct net_device * netdev)62 bpf_offload_find_netdev(struct net_device *netdev)
63 {
64 lockdep_assert_held(&bpf_devs_lock);
65
66 return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
67 }
68
__bpf_offload_dev_netdev_register(struct bpf_offload_dev * offdev,struct net_device * netdev)69 static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
70 struct net_device *netdev)
71 {
72 struct bpf_offload_netdev *ondev;
73 int err;
74
75 ondev = kzalloc_obj(*ondev);
76 if (!ondev)
77 return -ENOMEM;
78
79 ondev->netdev = netdev;
80 ondev->offdev = offdev;
81 INIT_LIST_HEAD(&ondev->progs);
82 INIT_LIST_HEAD(&ondev->maps);
83
84 err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
85 if (err) {
86 netdev_warn(netdev, "failed to register for BPF offload\n");
87 goto err_free;
88 }
89
90 if (offdev)
91 list_add(&ondev->offdev_netdevs, &offdev->netdevs);
92 return 0;
93
94 err_free:
95 kfree(ondev);
96 return err;
97 }
98
__bpf_prog_offload_destroy(struct bpf_prog * prog)99 static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
100 {
101 struct bpf_prog_offload *offload = prog->aux->offload;
102
103 if (offload->dev_state)
104 offload->offdev->ops->destroy(prog);
105
106 list_del_init(&offload->offloads);
107 kfree(offload);
108 prog->aux->offload = NULL;
109 }
110
bpf_map_offload_ndo(struct bpf_offloaded_map * offmap,enum bpf_netdev_command cmd)111 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
112 enum bpf_netdev_command cmd)
113 {
114 struct netdev_bpf data = {};
115 struct net_device *netdev;
116
117 ASSERT_RTNL();
118
119 data.command = cmd;
120 data.offmap = offmap;
121 /* Caller must make sure netdev is valid */
122 netdev = offmap->netdev;
123
124 return netdev->netdev_ops->ndo_bpf(netdev, &data);
125 }
126
__bpf_map_offload_destroy(struct bpf_offloaded_map * offmap)127 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
128 {
129 WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
130 /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
131 bpf_map_free_id(&offmap->map);
132 list_del_init(&offmap->offloads);
133 offmap->netdev = NULL;
134 }
135
__bpf_offload_dev_netdev_unregister(struct bpf_offload_dev * offdev,struct net_device * netdev)136 static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
137 struct net_device *netdev)
138 {
139 struct bpf_offload_netdev *ondev, *altdev = NULL;
140 struct bpf_offloaded_map *offmap, *mtmp;
141 struct bpf_prog_offload *offload, *ptmp;
142
143 ASSERT_RTNL();
144
145 ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
146 if (WARN_ON(!ondev))
147 return;
148
149 WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
150
151 /* Try to move the objects to another netdev of the device */
152 if (offdev) {
153 list_del(&ondev->offdev_netdevs);
154 altdev = list_first_entry_or_null(&offdev->netdevs,
155 struct bpf_offload_netdev,
156 offdev_netdevs);
157 }
158
159 if (altdev) {
160 list_for_each_entry(offload, &ondev->progs, offloads)
161 offload->netdev = altdev->netdev;
162 list_splice_init(&ondev->progs, &altdev->progs);
163
164 list_for_each_entry(offmap, &ondev->maps, offloads)
165 offmap->netdev = altdev->netdev;
166 list_splice_init(&ondev->maps, &altdev->maps);
167 } else {
168 list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
169 __bpf_prog_offload_destroy(offload->prog);
170 list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
171 __bpf_map_offload_destroy(offmap);
172 }
173
174 WARN_ON(!list_empty(&ondev->progs));
175 WARN_ON(!list_empty(&ondev->maps));
176 kfree(ondev);
177 }
178
__bpf_prog_dev_bound_init(struct bpf_prog * prog,struct net_device * netdev)179 static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *netdev)
180 {
181 struct bpf_offload_netdev *ondev;
182 struct bpf_prog_offload *offload;
183 int err;
184
185 offload = kzalloc_obj(*offload, GFP_USER);
186 if (!offload)
187 return -ENOMEM;
188
189 offload->prog = prog;
190 offload->netdev = netdev;
191
192 ondev = bpf_offload_find_netdev(offload->netdev);
193 /* When program is offloaded require presence of "true"
194 * bpf_offload_netdev, avoid the one created for !ondev case below.
195 */
196 if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) {
197 err = -EINVAL;
198 goto err_free;
199 }
200 if (!ondev) {
201 /* When only binding to the device, explicitly
202 * create an entry in the hashtable.
203 */
204 err = __bpf_offload_dev_netdev_register(NULL, offload->netdev);
205 if (err)
206 goto err_free;
207 ondev = bpf_offload_find_netdev(offload->netdev);
208 }
209 offload->offdev = ondev->offdev;
210 prog->aux->offload = offload;
211 list_add_tail(&offload->offloads, &ondev->progs);
212
213 return 0;
214 err_free:
215 kfree(offload);
216 return err;
217 }
218
bpf_prog_dev_bound_init(struct bpf_prog * prog,union bpf_attr * attr)219 int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr)
220 {
221 struct net_device *netdev;
222 int err;
223
224 if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
225 attr->prog_type != BPF_PROG_TYPE_XDP)
226 return -EINVAL;
227
228 if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS))
229 return -EINVAL;
230
231 /* Frags are allowed only if program is dev-bound-only, but not
232 * if it is requesting bpf offload.
233 */
234 if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS &&
235 !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY))
236 return -EINVAL;
237
238 if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS &&
239 attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)
240 return -EINVAL;
241
242 netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex);
243 if (!netdev)
244 return -EINVAL;
245
246 err = bpf_dev_offload_check(netdev);
247 if (err)
248 goto out;
249
250 prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY);
251
252 down_write(&bpf_devs_lock);
253 err = __bpf_prog_dev_bound_init(prog, netdev);
254 up_write(&bpf_devs_lock);
255
256 out:
257 dev_put(netdev);
258 return err;
259 }
260
bpf_prog_dev_bound_inherit(struct bpf_prog * new_prog,struct bpf_prog * old_prog)261 int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog)
262 {
263 int err;
264
265 if (!bpf_prog_is_dev_bound(old_prog->aux))
266 return 0;
267
268 if (bpf_prog_is_offloaded(old_prog->aux))
269 return -EINVAL;
270
271 new_prog->aux->dev_bound = old_prog->aux->dev_bound;
272 new_prog->aux->offload_requested = old_prog->aux->offload_requested;
273
274 down_write(&bpf_devs_lock);
275 if (!old_prog->aux->offload) {
276 err = -EINVAL;
277 goto out;
278 }
279
280 err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev);
281
282 out:
283 up_write(&bpf_devs_lock);
284 return err;
285 }
286
bpf_prog_offload_verifier_prep(struct bpf_prog * prog)287 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
288 {
289 struct bpf_prog_offload *offload;
290 int ret = -ENODEV;
291
292 down_read(&bpf_devs_lock);
293 offload = prog->aux->offload;
294 if (offload) {
295 ret = offload->offdev->ops->prepare(prog);
296 offload->dev_state = !ret;
297 }
298 up_read(&bpf_devs_lock);
299
300 return ret;
301 }
302
bpf_prog_offload_verify_insn(struct bpf_verifier_env * env,int insn_idx,int prev_insn_idx)303 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
304 int insn_idx, int prev_insn_idx)
305 {
306 struct bpf_prog_offload *offload;
307 int ret = -ENODEV;
308
309 down_read(&bpf_devs_lock);
310 offload = env->prog->aux->offload;
311 if (offload)
312 ret = offload->offdev->ops->insn_hook(env, insn_idx,
313 prev_insn_idx);
314 up_read(&bpf_devs_lock);
315
316 return ret;
317 }
318
bpf_prog_offload_finalize(struct bpf_verifier_env * env)319 int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
320 {
321 struct bpf_prog_offload *offload;
322 int ret = -ENODEV;
323
324 down_read(&bpf_devs_lock);
325 offload = env->prog->aux->offload;
326 if (offload) {
327 if (offload->offdev->ops->finalize)
328 ret = offload->offdev->ops->finalize(env);
329 else
330 ret = 0;
331 }
332 up_read(&bpf_devs_lock);
333
334 return ret;
335 }
336
337 void
bpf_prog_offload_replace_insn(struct bpf_verifier_env * env,u32 off,struct bpf_insn * insn)338 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
339 struct bpf_insn *insn)
340 {
341 const struct bpf_prog_offload_ops *ops;
342 struct bpf_prog_offload *offload;
343 int ret = -EOPNOTSUPP;
344
345 down_read(&bpf_devs_lock);
346 offload = env->prog->aux->offload;
347 if (offload) {
348 ops = offload->offdev->ops;
349 if (!offload->opt_failed && ops->replace_insn)
350 ret = ops->replace_insn(env, off, insn);
351 offload->opt_failed |= ret;
352 }
353 up_read(&bpf_devs_lock);
354 }
355
356 void
bpf_prog_offload_remove_insns(struct bpf_verifier_env * env,u32 off,u32 cnt)357 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
358 {
359 struct bpf_prog_offload *offload;
360 int ret = -EOPNOTSUPP;
361
362 down_read(&bpf_devs_lock);
363 offload = env->prog->aux->offload;
364 if (offload) {
365 if (!offload->opt_failed && offload->offdev->ops->remove_insns)
366 ret = offload->offdev->ops->remove_insns(env, off, cnt);
367 offload->opt_failed |= ret;
368 }
369 up_read(&bpf_devs_lock);
370 }
371
bpf_prog_dev_bound_destroy(struct bpf_prog * prog)372 void bpf_prog_dev_bound_destroy(struct bpf_prog *prog)
373 {
374 struct bpf_offload_netdev *ondev;
375 struct net_device *netdev;
376
377 rtnl_lock();
378 down_write(&bpf_devs_lock);
379 if (prog->aux->offload) {
380 list_del_init(&prog->aux->offload->offloads);
381
382 netdev = prog->aux->offload->netdev;
383 __bpf_prog_offload_destroy(prog);
384
385 ondev = bpf_offload_find_netdev(netdev);
386 if (!ondev->offdev && list_empty(&ondev->progs))
387 __bpf_offload_dev_netdev_unregister(NULL, netdev);
388 }
389 up_write(&bpf_devs_lock);
390 rtnl_unlock();
391 }
392
bpf_prog_offload_translate(struct bpf_prog * prog)393 static int bpf_prog_offload_translate(struct bpf_prog *prog)
394 {
395 struct bpf_prog_offload *offload;
396 int ret = -ENODEV;
397
398 down_read(&bpf_devs_lock);
399 offload = prog->aux->offload;
400 if (offload)
401 ret = offload->offdev->ops->translate(prog);
402 up_read(&bpf_devs_lock);
403
404 return ret;
405 }
406
bpf_prog_warn_on_exec(const void * ctx,const struct bpf_insn * insn)407 static unsigned int bpf_prog_warn_on_exec(const void *ctx,
408 const struct bpf_insn *insn)
409 {
410 WARN(1, "attempt to execute device eBPF program on the host!");
411 return 0;
412 }
413
bpf_prog_offload_compile(struct bpf_prog * prog)414 int bpf_prog_offload_compile(struct bpf_prog *prog)
415 {
416 prog->bpf_func = bpf_prog_warn_on_exec;
417
418 return bpf_prog_offload_translate(prog);
419 }
420
421 struct ns_get_path_bpf_prog_args {
422 struct bpf_prog *prog;
423 struct bpf_prog_info *info;
424 };
425
bpf_prog_offload_info_fill_ns(void * private_data)426 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
427 {
428 struct ns_get_path_bpf_prog_args *args = private_data;
429 struct bpf_prog_aux *aux = args->prog->aux;
430 struct ns_common *ns;
431 struct net *net;
432
433 rtnl_lock();
434 down_read(&bpf_devs_lock);
435
436 if (aux->offload) {
437 args->info->ifindex = aux->offload->netdev->ifindex;
438 net = maybe_get_net(dev_net(aux->offload->netdev));
439 ns = net ? &net->ns : NULL;
440 } else {
441 args->info->ifindex = 0;
442 ns = NULL;
443 }
444
445 up_read(&bpf_devs_lock);
446 rtnl_unlock();
447
448 return ns;
449 }
450
bpf_prog_offload_info_fill(struct bpf_prog_info * info,struct bpf_prog * prog)451 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
452 struct bpf_prog *prog)
453 {
454 struct ns_get_path_bpf_prog_args args = {
455 .prog = prog,
456 .info = info,
457 };
458 struct bpf_prog_aux *aux = prog->aux;
459 struct inode *ns_inode;
460 struct path ns_path;
461 char __user *uinsns;
462 int res;
463 u32 ulen;
464
465 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
466 if (res) {
467 if (!info->ifindex)
468 return -ENODEV;
469 return res;
470 }
471
472 down_read(&bpf_devs_lock);
473
474 if (!aux->offload) {
475 up_read(&bpf_devs_lock);
476 return -ENODEV;
477 }
478
479 ulen = info->jited_prog_len;
480 info->jited_prog_len = aux->offload->jited_len;
481 if (info->jited_prog_len && ulen) {
482 uinsns = u64_to_user_ptr(info->jited_prog_insns);
483 ulen = min_t(u32, info->jited_prog_len, ulen);
484 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
485 up_read(&bpf_devs_lock);
486 return -EFAULT;
487 }
488 }
489
490 up_read(&bpf_devs_lock);
491
492 ns_inode = ns_path.dentry->d_inode;
493 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
494 info->netns_ino = ns_inode->i_ino;
495 path_put(&ns_path);
496
497 return 0;
498 }
499
500 const struct bpf_prog_ops bpf_offload_prog_ops = {
501 };
502
bpf_map_offload_map_alloc(union bpf_attr * attr)503 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
504 {
505 struct net *net = current->nsproxy->net_ns;
506 struct bpf_offload_netdev *ondev;
507 struct bpf_offloaded_map *offmap;
508 int err;
509
510 if (!capable(CAP_SYS_ADMIN))
511 return ERR_PTR(-EPERM);
512 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
513 attr->map_type != BPF_MAP_TYPE_HASH)
514 return ERR_PTR(-EINVAL);
515
516 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE);
517 if (!offmap)
518 return ERR_PTR(-ENOMEM);
519
520 bpf_map_init_from_attr(&offmap->map, attr);
521 rtnl_lock();
522 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
523 err = bpf_dev_offload_check(offmap->netdev);
524 if (err)
525 goto err_unlock_rtnl;
526
527 netdev_lock_ops(offmap->netdev);
528 down_write(&bpf_devs_lock);
529
530 ondev = bpf_offload_find_netdev(offmap->netdev);
531 if (!ondev) {
532 err = -EINVAL;
533 goto err_unlock;
534 }
535
536 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
537 if (err)
538 goto err_unlock;
539
540 list_add_tail(&offmap->offloads, &ondev->maps);
541 up_write(&bpf_devs_lock);
542 netdev_unlock_ops(offmap->netdev);
543 rtnl_unlock();
544
545 return &offmap->map;
546
547 err_unlock:
548 up_write(&bpf_devs_lock);
549 netdev_unlock_ops(offmap->netdev);
550 err_unlock_rtnl:
551 rtnl_unlock();
552 bpf_map_area_free(offmap);
553 return ERR_PTR(err);
554 }
555
bpf_map_offload_map_free(struct bpf_map * map)556 void bpf_map_offload_map_free(struct bpf_map *map)
557 {
558 struct bpf_offloaded_map *offmap = map_to_offmap(map);
559
560 rtnl_lock();
561 down_write(&bpf_devs_lock);
562 if (offmap->netdev)
563 __bpf_map_offload_destroy(offmap);
564 up_write(&bpf_devs_lock);
565 rtnl_unlock();
566
567 bpf_map_area_free(offmap);
568 }
569
bpf_map_offload_map_mem_usage(const struct bpf_map * map)570 u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
571 {
572 /* The memory dynamically allocated in netdev dev_ops is not counted */
573 return sizeof(struct bpf_offloaded_map);
574 }
575
bpf_map_offload_lookup_elem(struct bpf_map * map,void * key,void * value)576 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
577 {
578 struct bpf_offloaded_map *offmap = map_to_offmap(map);
579 int ret = -ENODEV;
580
581 down_read(&bpf_devs_lock);
582 if (offmap->netdev)
583 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
584 up_read(&bpf_devs_lock);
585
586 return ret;
587 }
588
bpf_map_offload_update_elem(struct bpf_map * map,void * key,void * value,u64 flags)589 int bpf_map_offload_update_elem(struct bpf_map *map,
590 void *key, void *value, u64 flags)
591 {
592 struct bpf_offloaded_map *offmap = map_to_offmap(map);
593 int ret = -ENODEV;
594
595 if (unlikely(flags > BPF_EXIST))
596 return -EINVAL;
597
598 down_read(&bpf_devs_lock);
599 if (offmap->netdev)
600 ret = offmap->dev_ops->map_update_elem(offmap, key, value,
601 flags);
602 up_read(&bpf_devs_lock);
603
604 return ret;
605 }
606
bpf_map_offload_delete_elem(struct bpf_map * map,void * key)607 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
608 {
609 struct bpf_offloaded_map *offmap = map_to_offmap(map);
610 int ret = -ENODEV;
611
612 down_read(&bpf_devs_lock);
613 if (offmap->netdev)
614 ret = offmap->dev_ops->map_delete_elem(offmap, key);
615 up_read(&bpf_devs_lock);
616
617 return ret;
618 }
619
bpf_map_offload_get_next_key(struct bpf_map * map,void * key,void * next_key)620 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
621 {
622 struct bpf_offloaded_map *offmap = map_to_offmap(map);
623 int ret = -ENODEV;
624
625 down_read(&bpf_devs_lock);
626 if (offmap->netdev)
627 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
628 up_read(&bpf_devs_lock);
629
630 return ret;
631 }
632
633 struct ns_get_path_bpf_map_args {
634 struct bpf_offloaded_map *offmap;
635 struct bpf_map_info *info;
636 };
637
bpf_map_offload_info_fill_ns(void * private_data)638 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
639 {
640 struct ns_get_path_bpf_map_args *args = private_data;
641 struct ns_common *ns;
642 struct net *net;
643
644 rtnl_lock();
645 down_read(&bpf_devs_lock);
646
647 if (args->offmap->netdev) {
648 args->info->ifindex = args->offmap->netdev->ifindex;
649 net = maybe_get_net(dev_net(args->offmap->netdev));
650 ns = net ? &net->ns : NULL;
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
bpf_map_offload_info_fill(struct bpf_map_info * info,struct bpf_map * map)662 int 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
__bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)687 static 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 if (!bpf_prog_is_offloaded(prog->aux))
702 return false;
703
704 ondev1 = bpf_offload_find_netdev(offload->netdev);
705 ondev2 = bpf_offload_find_netdev(netdev);
706
707 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
708 }
709
bpf_offload_dev_match(struct bpf_prog * prog,struct net_device * netdev)710 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
711 {
712 bool ret;
713
714 down_read(&bpf_devs_lock);
715 ret = __bpf_offload_dev_match(prog, netdev);
716 up_read(&bpf_devs_lock);
717
718 return ret;
719 }
720 EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
721
bpf_prog_dev_bound_match(const struct bpf_prog * lhs,const struct bpf_prog * rhs)722 bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs)
723 {
724 bool ret;
725
726 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux))
727 return false;
728
729 down_read(&bpf_devs_lock);
730 ret = lhs->aux->offload && rhs->aux->offload &&
731 lhs->aux->offload->netdev &&
732 lhs->aux->offload->netdev == rhs->aux->offload->netdev;
733 up_read(&bpf_devs_lock);
734
735 return ret;
736 }
737
bpf_offload_prog_map_match(struct bpf_prog * prog,struct bpf_map * map)738 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
739 {
740 struct bpf_offloaded_map *offmap;
741 bool ret;
742
743 if (!bpf_map_is_offloaded(map))
744 return bpf_map_offload_neutral(map);
745 offmap = map_to_offmap(map);
746
747 down_read(&bpf_devs_lock);
748 ret = __bpf_offload_dev_match(prog, offmap->netdev);
749 up_read(&bpf_devs_lock);
750
751 return ret;
752 }
753
bpf_offload_dev_netdev_register(struct bpf_offload_dev * offdev,struct net_device * netdev)754 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
755 struct net_device *netdev)
756 {
757 int err;
758
759 down_write(&bpf_devs_lock);
760 err = __bpf_offload_dev_netdev_register(offdev, netdev);
761 up_write(&bpf_devs_lock);
762 return err;
763 }
764 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
765
bpf_offload_dev_netdev_unregister(struct bpf_offload_dev * offdev,struct net_device * netdev)766 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
767 struct net_device *netdev)
768 {
769 down_write(&bpf_devs_lock);
770 __bpf_offload_dev_netdev_unregister(offdev, netdev);
771 up_write(&bpf_devs_lock);
772 }
773 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
774
775 struct bpf_offload_dev *
bpf_offload_dev_create(const struct bpf_prog_offload_ops * ops,void * priv)776 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
777 {
778 struct bpf_offload_dev *offdev;
779
780 offdev = kzalloc_obj(*offdev);
781 if (!offdev)
782 return ERR_PTR(-ENOMEM);
783
784 offdev->ops = ops;
785 offdev->priv = priv;
786 INIT_LIST_HEAD(&offdev->netdevs);
787
788 return offdev;
789 }
790 EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
791
bpf_offload_dev_destroy(struct bpf_offload_dev * offdev)792 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
793 {
794 WARN_ON(!list_empty(&offdev->netdevs));
795 kfree(offdev);
796 }
797 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
798
bpf_offload_dev_priv(struct bpf_offload_dev * offdev)799 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
800 {
801 return offdev->priv;
802 }
803 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
804
bpf_dev_bound_netdev_unregister(struct net_device * dev)805 void bpf_dev_bound_netdev_unregister(struct net_device *dev)
806 {
807 struct bpf_offload_netdev *ondev;
808
809 ASSERT_RTNL();
810
811 down_write(&bpf_devs_lock);
812 ondev = bpf_offload_find_netdev(dev);
813 if (ondev && !ondev->offdev)
814 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev);
815 up_write(&bpf_devs_lock);
816 }
817
bpf_dev_bound_kfunc_check(struct bpf_verifier_log * log,struct bpf_prog_aux * prog_aux)818 int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log,
819 struct bpf_prog_aux *prog_aux)
820 {
821 if (!bpf_prog_is_dev_bound(prog_aux)) {
822 bpf_log(log, "metadata kfuncs require device-bound program\n");
823 return -EINVAL;
824 }
825
826 if (bpf_prog_is_offloaded(prog_aux)) {
827 bpf_log(log, "metadata kfuncs can't be offloaded\n");
828 return -EINVAL;
829 }
830
831 return 0;
832 }
833
bpf_dev_bound_resolve_kfunc(struct bpf_prog * prog,u32 func_id)834 void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
835 {
836 const struct xdp_metadata_ops *ops;
837 void *p = NULL;
838
839 /* We don't hold bpf_devs_lock while resolving several
840 * kfuncs and can race with the unregister_netdevice().
841 * We rely on bpf_dev_bound_match() check at attach
842 * to render this program unusable.
843 */
844 down_read(&bpf_devs_lock);
845 if (!prog->aux->offload)
846 goto out;
847
848 ops = prog->aux->offload->netdev->xdp_metadata_ops;
849 if (!ops)
850 goto out;
851
852 #define XDP_METADATA_KFUNC(name, _, __, xmo) \
853 if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
854 XDP_METADATA_KFUNC_xxx
855 #undef XDP_METADATA_KFUNC
856
857 out:
858 up_read(&bpf_devs_lock);
859
860 return p;
861 }
862
bpf_offload_init(void)863 static int __init bpf_offload_init(void)
864 {
865 return rhashtable_init(&offdevs, &offdevs_params);
866 }
867
868 core_initcall(bpf_offload_init);
869