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99c55f7d AS |
1 | /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
2 | * | |
3 | * This program is free software; you can redistribute it and/or | |
4 | * modify it under the terms of version 2 of the GNU General Public | |
5 | * License as published by the Free Software Foundation. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, but | |
8 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
10 | * General Public License for more details. | |
11 | */ | |
12 | #include <linux/bpf.h> | |
13 | #include <linux/syscalls.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/anon_inodes.h> | |
db20fd2b | 16 | #include <linux/file.h> |
09756af4 AS |
17 | #include <linux/license.h> |
18 | #include <linux/filter.h> | |
2541517c | 19 | #include <linux/version.h> |
99c55f7d | 20 | |
1be7f75d AS |
21 | int sysctl_unprivileged_bpf_disabled __read_mostly; |
22 | ||
99c55f7d AS |
23 | static LIST_HEAD(bpf_map_types); |
24 | ||
25 | static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) | |
26 | { | |
27 | struct bpf_map_type_list *tl; | |
28 | struct bpf_map *map; | |
29 | ||
30 | list_for_each_entry(tl, &bpf_map_types, list_node) { | |
31 | if (tl->type == attr->map_type) { | |
32 | map = tl->ops->map_alloc(attr); | |
33 | if (IS_ERR(map)) | |
34 | return map; | |
35 | map->ops = tl->ops; | |
36 | map->map_type = attr->map_type; | |
37 | return map; | |
38 | } | |
39 | } | |
40 | return ERR_PTR(-EINVAL); | |
41 | } | |
42 | ||
43 | /* boot time registration of different map implementations */ | |
44 | void bpf_register_map_type(struct bpf_map_type_list *tl) | |
45 | { | |
46 | list_add(&tl->list_node, &bpf_map_types); | |
47 | } | |
48 | ||
aaac3ba9 AS |
49 | static int bpf_map_charge_memlock(struct bpf_map *map) |
50 | { | |
51 | struct user_struct *user = get_current_user(); | |
52 | unsigned long memlock_limit; | |
53 | ||
54 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
55 | ||
56 | atomic_long_add(map->pages, &user->locked_vm); | |
57 | ||
58 | if (atomic_long_read(&user->locked_vm) > memlock_limit) { | |
59 | atomic_long_sub(map->pages, &user->locked_vm); | |
60 | free_uid(user); | |
61 | return -EPERM; | |
62 | } | |
63 | map->user = user; | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static void bpf_map_uncharge_memlock(struct bpf_map *map) | |
68 | { | |
69 | struct user_struct *user = map->user; | |
70 | ||
71 | atomic_long_sub(map->pages, &user->locked_vm); | |
72 | free_uid(user); | |
73 | } | |
74 | ||
99c55f7d AS |
75 | /* called from workqueue */ |
76 | static void bpf_map_free_deferred(struct work_struct *work) | |
77 | { | |
78 | struct bpf_map *map = container_of(work, struct bpf_map, work); | |
79 | ||
aaac3ba9 | 80 | bpf_map_uncharge_memlock(map); |
99c55f7d AS |
81 | /* implementation dependent freeing */ |
82 | map->ops->map_free(map); | |
83 | } | |
84 | ||
c9da161c DB |
85 | static void bpf_map_put_uref(struct bpf_map *map) |
86 | { | |
87 | if (atomic_dec_and_test(&map->usercnt)) { | |
88 | if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) | |
89 | bpf_fd_array_map_clear(map); | |
90 | } | |
91 | } | |
92 | ||
99c55f7d AS |
93 | /* decrement map refcnt and schedule it for freeing via workqueue |
94 | * (unrelying map implementation ops->map_free() might sleep) | |
95 | */ | |
96 | void bpf_map_put(struct bpf_map *map) | |
97 | { | |
98 | if (atomic_dec_and_test(&map->refcnt)) { | |
99 | INIT_WORK(&map->work, bpf_map_free_deferred); | |
100 | schedule_work(&map->work); | |
101 | } | |
102 | } | |
103 | ||
c9da161c | 104 | void bpf_map_put_with_uref(struct bpf_map *map) |
99c55f7d | 105 | { |
c9da161c | 106 | bpf_map_put_uref(map); |
99c55f7d | 107 | bpf_map_put(map); |
c9da161c DB |
108 | } |
109 | ||
110 | static int bpf_map_release(struct inode *inode, struct file *filp) | |
111 | { | |
112 | bpf_map_put_with_uref(filp->private_data); | |
99c55f7d AS |
113 | return 0; |
114 | } | |
115 | ||
116 | static const struct file_operations bpf_map_fops = { | |
117 | .release = bpf_map_release, | |
118 | }; | |
119 | ||
b2197755 | 120 | int bpf_map_new_fd(struct bpf_map *map) |
aa79781b DB |
121 | { |
122 | return anon_inode_getfd("bpf-map", &bpf_map_fops, map, | |
123 | O_RDWR | O_CLOEXEC); | |
124 | } | |
125 | ||
99c55f7d AS |
126 | /* helper macro to check that unused fields 'union bpf_attr' are zero */ |
127 | #define CHECK_ATTR(CMD) \ | |
128 | memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ | |
129 | sizeof(attr->CMD##_LAST_FIELD), 0, \ | |
130 | sizeof(*attr) - \ | |
131 | offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ | |
132 | sizeof(attr->CMD##_LAST_FIELD)) != NULL | |
133 | ||
134 | #define BPF_MAP_CREATE_LAST_FIELD max_entries | |
135 | /* called via syscall */ | |
136 | static int map_create(union bpf_attr *attr) | |
137 | { | |
138 | struct bpf_map *map; | |
139 | int err; | |
140 | ||
141 | err = CHECK_ATTR(BPF_MAP_CREATE); | |
142 | if (err) | |
143 | return -EINVAL; | |
144 | ||
145 | /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ | |
146 | map = find_and_alloc_map(attr); | |
147 | if (IS_ERR(map)) | |
148 | return PTR_ERR(map); | |
149 | ||
150 | atomic_set(&map->refcnt, 1); | |
c9da161c | 151 | atomic_set(&map->usercnt, 1); |
99c55f7d | 152 | |
aaac3ba9 AS |
153 | err = bpf_map_charge_memlock(map); |
154 | if (err) | |
155 | goto free_map; | |
156 | ||
aa79781b | 157 | err = bpf_map_new_fd(map); |
99c55f7d AS |
158 | if (err < 0) |
159 | /* failed to allocate fd */ | |
160 | goto free_map; | |
161 | ||
162 | return err; | |
163 | ||
164 | free_map: | |
165 | map->ops->map_free(map); | |
166 | return err; | |
167 | } | |
168 | ||
db20fd2b AS |
169 | /* if error is returned, fd is released. |
170 | * On success caller should complete fd access with matching fdput() | |
171 | */ | |
c2101297 | 172 | struct bpf_map *__bpf_map_get(struct fd f) |
db20fd2b | 173 | { |
db20fd2b AS |
174 | if (!f.file) |
175 | return ERR_PTR(-EBADF); | |
db20fd2b AS |
176 | if (f.file->f_op != &bpf_map_fops) { |
177 | fdput(f); | |
178 | return ERR_PTR(-EINVAL); | |
179 | } | |
180 | ||
c2101297 DB |
181 | return f.file->private_data; |
182 | } | |
183 | ||
c9da161c DB |
184 | void bpf_map_inc(struct bpf_map *map, bool uref) |
185 | { | |
186 | atomic_inc(&map->refcnt); | |
187 | if (uref) | |
188 | atomic_inc(&map->usercnt); | |
189 | } | |
190 | ||
191 | struct bpf_map *bpf_map_get_with_uref(u32 ufd) | |
c2101297 DB |
192 | { |
193 | struct fd f = fdget(ufd); | |
194 | struct bpf_map *map; | |
195 | ||
196 | map = __bpf_map_get(f); | |
197 | if (IS_ERR(map)) | |
198 | return map; | |
199 | ||
c9da161c | 200 | bpf_map_inc(map, true); |
c2101297 | 201 | fdput(f); |
db20fd2b AS |
202 | |
203 | return map; | |
204 | } | |
205 | ||
206 | /* helper to convert user pointers passed inside __aligned_u64 fields */ | |
207 | static void __user *u64_to_ptr(__u64 val) | |
208 | { | |
209 | return (void __user *) (unsigned long) val; | |
210 | } | |
211 | ||
212 | /* last field in 'union bpf_attr' used by this command */ | |
213 | #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value | |
214 | ||
215 | static int map_lookup_elem(union bpf_attr *attr) | |
216 | { | |
217 | void __user *ukey = u64_to_ptr(attr->key); | |
218 | void __user *uvalue = u64_to_ptr(attr->value); | |
219 | int ufd = attr->map_fd; | |
db20fd2b | 220 | struct bpf_map *map; |
8ebe667c | 221 | void *key, *value, *ptr; |
592867bf | 222 | struct fd f; |
db20fd2b AS |
223 | int err; |
224 | ||
225 | if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) | |
226 | return -EINVAL; | |
227 | ||
592867bf | 228 | f = fdget(ufd); |
c2101297 | 229 | map = __bpf_map_get(f); |
db20fd2b AS |
230 | if (IS_ERR(map)) |
231 | return PTR_ERR(map); | |
232 | ||
233 | err = -ENOMEM; | |
234 | key = kmalloc(map->key_size, GFP_USER); | |
235 | if (!key) | |
236 | goto err_put; | |
237 | ||
238 | err = -EFAULT; | |
239 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
240 | goto free_key; | |
241 | ||
8ebe667c | 242 | err = -ENOMEM; |
01b3f521 | 243 | value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN); |
db20fd2b | 244 | if (!value) |
8ebe667c AS |
245 | goto free_key; |
246 | ||
247 | rcu_read_lock(); | |
248 | ptr = map->ops->map_lookup_elem(map, key); | |
249 | if (ptr) | |
250 | memcpy(value, ptr, map->value_size); | |
251 | rcu_read_unlock(); | |
252 | ||
253 | err = -ENOENT; | |
254 | if (!ptr) | |
255 | goto free_value; | |
db20fd2b AS |
256 | |
257 | err = -EFAULT; | |
258 | if (copy_to_user(uvalue, value, map->value_size) != 0) | |
8ebe667c | 259 | goto free_value; |
db20fd2b AS |
260 | |
261 | err = 0; | |
262 | ||
8ebe667c AS |
263 | free_value: |
264 | kfree(value); | |
db20fd2b AS |
265 | free_key: |
266 | kfree(key); | |
267 | err_put: | |
268 | fdput(f); | |
269 | return err; | |
270 | } | |
271 | ||
3274f520 | 272 | #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags |
db20fd2b AS |
273 | |
274 | static int map_update_elem(union bpf_attr *attr) | |
275 | { | |
276 | void __user *ukey = u64_to_ptr(attr->key); | |
277 | void __user *uvalue = u64_to_ptr(attr->value); | |
278 | int ufd = attr->map_fd; | |
db20fd2b AS |
279 | struct bpf_map *map; |
280 | void *key, *value; | |
592867bf | 281 | struct fd f; |
db20fd2b AS |
282 | int err; |
283 | ||
284 | if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) | |
285 | return -EINVAL; | |
286 | ||
592867bf | 287 | f = fdget(ufd); |
c2101297 | 288 | map = __bpf_map_get(f); |
db20fd2b AS |
289 | if (IS_ERR(map)) |
290 | return PTR_ERR(map); | |
291 | ||
292 | err = -ENOMEM; | |
293 | key = kmalloc(map->key_size, GFP_USER); | |
294 | if (!key) | |
295 | goto err_put; | |
296 | ||
297 | err = -EFAULT; | |
298 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
299 | goto free_key; | |
300 | ||
301 | err = -ENOMEM; | |
01b3f521 | 302 | value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN); |
db20fd2b AS |
303 | if (!value) |
304 | goto free_key; | |
305 | ||
306 | err = -EFAULT; | |
307 | if (copy_from_user(value, uvalue, map->value_size) != 0) | |
308 | goto free_value; | |
309 | ||
310 | /* eBPF program that use maps are running under rcu_read_lock(), | |
311 | * therefore all map accessors rely on this fact, so do the same here | |
312 | */ | |
313 | rcu_read_lock(); | |
3274f520 | 314 | err = map->ops->map_update_elem(map, key, value, attr->flags); |
db20fd2b AS |
315 | rcu_read_unlock(); |
316 | ||
317 | free_value: | |
318 | kfree(value); | |
319 | free_key: | |
320 | kfree(key); | |
321 | err_put: | |
322 | fdput(f); | |
323 | return err; | |
324 | } | |
325 | ||
326 | #define BPF_MAP_DELETE_ELEM_LAST_FIELD key | |
327 | ||
328 | static int map_delete_elem(union bpf_attr *attr) | |
329 | { | |
330 | void __user *ukey = u64_to_ptr(attr->key); | |
331 | int ufd = attr->map_fd; | |
db20fd2b | 332 | struct bpf_map *map; |
592867bf | 333 | struct fd f; |
db20fd2b AS |
334 | void *key; |
335 | int err; | |
336 | ||
337 | if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) | |
338 | return -EINVAL; | |
339 | ||
592867bf | 340 | f = fdget(ufd); |
c2101297 | 341 | map = __bpf_map_get(f); |
db20fd2b AS |
342 | if (IS_ERR(map)) |
343 | return PTR_ERR(map); | |
344 | ||
345 | err = -ENOMEM; | |
346 | key = kmalloc(map->key_size, GFP_USER); | |
347 | if (!key) | |
348 | goto err_put; | |
349 | ||
350 | err = -EFAULT; | |
351 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
352 | goto free_key; | |
353 | ||
354 | rcu_read_lock(); | |
355 | err = map->ops->map_delete_elem(map, key); | |
356 | rcu_read_unlock(); | |
357 | ||
358 | free_key: | |
359 | kfree(key); | |
360 | err_put: | |
361 | fdput(f); | |
362 | return err; | |
363 | } | |
364 | ||
365 | /* last field in 'union bpf_attr' used by this command */ | |
366 | #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key | |
367 | ||
368 | static int map_get_next_key(union bpf_attr *attr) | |
369 | { | |
370 | void __user *ukey = u64_to_ptr(attr->key); | |
371 | void __user *unext_key = u64_to_ptr(attr->next_key); | |
372 | int ufd = attr->map_fd; | |
db20fd2b AS |
373 | struct bpf_map *map; |
374 | void *key, *next_key; | |
592867bf | 375 | struct fd f; |
db20fd2b AS |
376 | int err; |
377 | ||
378 | if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) | |
379 | return -EINVAL; | |
380 | ||
592867bf | 381 | f = fdget(ufd); |
c2101297 | 382 | map = __bpf_map_get(f); |
db20fd2b AS |
383 | if (IS_ERR(map)) |
384 | return PTR_ERR(map); | |
385 | ||
386 | err = -ENOMEM; | |
387 | key = kmalloc(map->key_size, GFP_USER); | |
388 | if (!key) | |
389 | goto err_put; | |
390 | ||
391 | err = -EFAULT; | |
392 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
393 | goto free_key; | |
394 | ||
395 | err = -ENOMEM; | |
396 | next_key = kmalloc(map->key_size, GFP_USER); | |
397 | if (!next_key) | |
398 | goto free_key; | |
399 | ||
400 | rcu_read_lock(); | |
401 | err = map->ops->map_get_next_key(map, key, next_key); | |
402 | rcu_read_unlock(); | |
403 | if (err) | |
404 | goto free_next_key; | |
405 | ||
406 | err = -EFAULT; | |
407 | if (copy_to_user(unext_key, next_key, map->key_size) != 0) | |
408 | goto free_next_key; | |
409 | ||
410 | err = 0; | |
411 | ||
412 | free_next_key: | |
413 | kfree(next_key); | |
414 | free_key: | |
415 | kfree(key); | |
416 | err_put: | |
417 | fdput(f); | |
418 | return err; | |
419 | } | |
420 | ||
09756af4 AS |
421 | static LIST_HEAD(bpf_prog_types); |
422 | ||
423 | static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) | |
424 | { | |
425 | struct bpf_prog_type_list *tl; | |
426 | ||
427 | list_for_each_entry(tl, &bpf_prog_types, list_node) { | |
428 | if (tl->type == type) { | |
429 | prog->aux->ops = tl->ops; | |
24701ece | 430 | prog->type = type; |
09756af4 AS |
431 | return 0; |
432 | } | |
433 | } | |
24701ece | 434 | |
09756af4 AS |
435 | return -EINVAL; |
436 | } | |
437 | ||
438 | void bpf_register_prog_type(struct bpf_prog_type_list *tl) | |
439 | { | |
440 | list_add(&tl->list_node, &bpf_prog_types); | |
441 | } | |
442 | ||
0a542a86 AS |
443 | /* fixup insn->imm field of bpf_call instructions: |
444 | * if (insn->imm == BPF_FUNC_map_lookup_elem) | |
445 | * insn->imm = bpf_map_lookup_elem - __bpf_call_base; | |
446 | * else if (insn->imm == BPF_FUNC_map_update_elem) | |
447 | * insn->imm = bpf_map_update_elem - __bpf_call_base; | |
448 | * else ... | |
449 | * | |
450 | * this function is called after eBPF program passed verification | |
451 | */ | |
452 | static void fixup_bpf_calls(struct bpf_prog *prog) | |
453 | { | |
454 | const struct bpf_func_proto *fn; | |
455 | int i; | |
456 | ||
457 | for (i = 0; i < prog->len; i++) { | |
458 | struct bpf_insn *insn = &prog->insnsi[i]; | |
459 | ||
460 | if (insn->code == (BPF_JMP | BPF_CALL)) { | |
461 | /* we reach here when program has bpf_call instructions | |
462 | * and it passed bpf_check(), means that | |
463 | * ops->get_func_proto must have been supplied, check it | |
464 | */ | |
465 | BUG_ON(!prog->aux->ops->get_func_proto); | |
466 | ||
c46646d0 DB |
467 | if (insn->imm == BPF_FUNC_get_route_realm) |
468 | prog->dst_needed = 1; | |
3ad00405 DB |
469 | if (insn->imm == BPF_FUNC_get_prandom_u32) |
470 | bpf_user_rnd_init_once(); | |
04fd61ab AS |
471 | if (insn->imm == BPF_FUNC_tail_call) { |
472 | /* mark bpf_tail_call as different opcode | |
473 | * to avoid conditional branch in | |
474 | * interpeter for every normal call | |
475 | * and to prevent accidental JITing by | |
476 | * JIT compiler that doesn't support | |
477 | * bpf_tail_call yet | |
478 | */ | |
479 | insn->imm = 0; | |
480 | insn->code |= BPF_X; | |
481 | continue; | |
482 | } | |
483 | ||
0a542a86 AS |
484 | fn = prog->aux->ops->get_func_proto(insn->imm); |
485 | /* all functions that have prototype and verifier allowed | |
486 | * programs to call them, must be real in-kernel functions | |
487 | */ | |
488 | BUG_ON(!fn->func); | |
489 | insn->imm = fn->func - __bpf_call_base; | |
490 | } | |
491 | } | |
492 | } | |
493 | ||
09756af4 AS |
494 | /* drop refcnt on maps used by eBPF program and free auxilary data */ |
495 | static void free_used_maps(struct bpf_prog_aux *aux) | |
496 | { | |
497 | int i; | |
498 | ||
499 | for (i = 0; i < aux->used_map_cnt; i++) | |
500 | bpf_map_put(aux->used_maps[i]); | |
501 | ||
502 | kfree(aux->used_maps); | |
503 | } | |
504 | ||
aaac3ba9 AS |
505 | static int bpf_prog_charge_memlock(struct bpf_prog *prog) |
506 | { | |
507 | struct user_struct *user = get_current_user(); | |
508 | unsigned long memlock_limit; | |
509 | ||
510 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
511 | ||
512 | atomic_long_add(prog->pages, &user->locked_vm); | |
513 | if (atomic_long_read(&user->locked_vm) > memlock_limit) { | |
514 | atomic_long_sub(prog->pages, &user->locked_vm); | |
515 | free_uid(user); | |
516 | return -EPERM; | |
517 | } | |
518 | prog->aux->user = user; | |
519 | return 0; | |
520 | } | |
521 | ||
522 | static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) | |
523 | { | |
524 | struct user_struct *user = prog->aux->user; | |
525 | ||
526 | atomic_long_sub(prog->pages, &user->locked_vm); | |
527 | free_uid(user); | |
528 | } | |
529 | ||
e9d8afa9 | 530 | static void __prog_put_common(struct rcu_head *rcu) |
abf2e7d6 AS |
531 | { |
532 | struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); | |
533 | ||
534 | free_used_maps(aux); | |
aaac3ba9 | 535 | bpf_prog_uncharge_memlock(aux->prog); |
abf2e7d6 AS |
536 | bpf_prog_free(aux->prog); |
537 | } | |
538 | ||
539 | /* version of bpf_prog_put() that is called after a grace period */ | |
540 | void bpf_prog_put_rcu(struct bpf_prog *prog) | |
541 | { | |
e9d8afa9 DB |
542 | if (atomic_dec_and_test(&prog->aux->refcnt)) |
543 | call_rcu(&prog->aux->rcu, __prog_put_common); | |
abf2e7d6 AS |
544 | } |
545 | ||
09756af4 AS |
546 | void bpf_prog_put(struct bpf_prog *prog) |
547 | { | |
e9d8afa9 DB |
548 | if (atomic_dec_and_test(&prog->aux->refcnt)) |
549 | __prog_put_common(&prog->aux->rcu); | |
09756af4 | 550 | } |
e2e9b654 | 551 | EXPORT_SYMBOL_GPL(bpf_prog_put); |
09756af4 AS |
552 | |
553 | static int bpf_prog_release(struct inode *inode, struct file *filp) | |
554 | { | |
555 | struct bpf_prog *prog = filp->private_data; | |
556 | ||
abf2e7d6 | 557 | bpf_prog_put_rcu(prog); |
09756af4 AS |
558 | return 0; |
559 | } | |
560 | ||
561 | static const struct file_operations bpf_prog_fops = { | |
562 | .release = bpf_prog_release, | |
563 | }; | |
564 | ||
b2197755 | 565 | int bpf_prog_new_fd(struct bpf_prog *prog) |
aa79781b DB |
566 | { |
567 | return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, | |
568 | O_RDWR | O_CLOEXEC); | |
569 | } | |
570 | ||
c2101297 | 571 | static struct bpf_prog *__bpf_prog_get(struct fd f) |
09756af4 | 572 | { |
09756af4 AS |
573 | if (!f.file) |
574 | return ERR_PTR(-EBADF); | |
09756af4 AS |
575 | if (f.file->f_op != &bpf_prog_fops) { |
576 | fdput(f); | |
577 | return ERR_PTR(-EINVAL); | |
578 | } | |
579 | ||
c2101297 | 580 | return f.file->private_data; |
09756af4 AS |
581 | } |
582 | ||
583 | /* called by sockets/tracing/seccomp before attaching program to an event | |
584 | * pairs with bpf_prog_put() | |
585 | */ | |
586 | struct bpf_prog *bpf_prog_get(u32 ufd) | |
587 | { | |
588 | struct fd f = fdget(ufd); | |
589 | struct bpf_prog *prog; | |
590 | ||
c2101297 | 591 | prog = __bpf_prog_get(f); |
09756af4 AS |
592 | if (IS_ERR(prog)) |
593 | return prog; | |
594 | ||
595 | atomic_inc(&prog->aux->refcnt); | |
596 | fdput(f); | |
c2101297 | 597 | |
09756af4 AS |
598 | return prog; |
599 | } | |
e2e9b654 | 600 | EXPORT_SYMBOL_GPL(bpf_prog_get); |
09756af4 AS |
601 | |
602 | /* last field in 'union bpf_attr' used by this command */ | |
2541517c | 603 | #define BPF_PROG_LOAD_LAST_FIELD kern_version |
09756af4 AS |
604 | |
605 | static int bpf_prog_load(union bpf_attr *attr) | |
606 | { | |
607 | enum bpf_prog_type type = attr->prog_type; | |
608 | struct bpf_prog *prog; | |
609 | int err; | |
610 | char license[128]; | |
611 | bool is_gpl; | |
612 | ||
613 | if (CHECK_ATTR(BPF_PROG_LOAD)) | |
614 | return -EINVAL; | |
615 | ||
616 | /* copy eBPF program license from user space */ | |
617 | if (strncpy_from_user(license, u64_to_ptr(attr->license), | |
618 | sizeof(license) - 1) < 0) | |
619 | return -EFAULT; | |
620 | license[sizeof(license) - 1] = 0; | |
621 | ||
622 | /* eBPF programs must be GPL compatible to use GPL-ed functions */ | |
623 | is_gpl = license_is_gpl_compatible(license); | |
624 | ||
625 | if (attr->insn_cnt >= BPF_MAXINSNS) | |
626 | return -EINVAL; | |
627 | ||
2541517c AS |
628 | if (type == BPF_PROG_TYPE_KPROBE && |
629 | attr->kern_version != LINUX_VERSION_CODE) | |
630 | return -EINVAL; | |
631 | ||
1be7f75d AS |
632 | if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN)) |
633 | return -EPERM; | |
634 | ||
09756af4 AS |
635 | /* plain bpf_prog allocation */ |
636 | prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); | |
637 | if (!prog) | |
638 | return -ENOMEM; | |
639 | ||
aaac3ba9 AS |
640 | err = bpf_prog_charge_memlock(prog); |
641 | if (err) | |
642 | goto free_prog_nouncharge; | |
643 | ||
09756af4 AS |
644 | prog->len = attr->insn_cnt; |
645 | ||
646 | err = -EFAULT; | |
647 | if (copy_from_user(prog->insns, u64_to_ptr(attr->insns), | |
648 | prog->len * sizeof(struct bpf_insn)) != 0) | |
649 | goto free_prog; | |
650 | ||
651 | prog->orig_prog = NULL; | |
a91263d5 | 652 | prog->jited = 0; |
09756af4 AS |
653 | |
654 | atomic_set(&prog->aux->refcnt, 1); | |
a91263d5 | 655 | prog->gpl_compatible = is_gpl ? 1 : 0; |
09756af4 AS |
656 | |
657 | /* find program type: socket_filter vs tracing_filter */ | |
658 | err = find_prog_type(type, prog); | |
659 | if (err < 0) | |
660 | goto free_prog; | |
661 | ||
662 | /* run eBPF verifier */ | |
9bac3d6d | 663 | err = bpf_check(&prog, attr); |
09756af4 AS |
664 | if (err < 0) |
665 | goto free_used_maps; | |
666 | ||
0a542a86 AS |
667 | /* fixup BPF_CALL->imm field */ |
668 | fixup_bpf_calls(prog); | |
669 | ||
09756af4 | 670 | /* eBPF program is ready to be JITed */ |
04fd61ab AS |
671 | err = bpf_prog_select_runtime(prog); |
672 | if (err < 0) | |
673 | goto free_used_maps; | |
09756af4 | 674 | |
aa79781b | 675 | err = bpf_prog_new_fd(prog); |
09756af4 AS |
676 | if (err < 0) |
677 | /* failed to allocate fd */ | |
678 | goto free_used_maps; | |
679 | ||
680 | return err; | |
681 | ||
682 | free_used_maps: | |
683 | free_used_maps(prog->aux); | |
684 | free_prog: | |
aaac3ba9 AS |
685 | bpf_prog_uncharge_memlock(prog); |
686 | free_prog_nouncharge: | |
09756af4 AS |
687 | bpf_prog_free(prog); |
688 | return err; | |
689 | } | |
690 | ||
b2197755 DB |
691 | #define BPF_OBJ_LAST_FIELD bpf_fd |
692 | ||
693 | static int bpf_obj_pin(const union bpf_attr *attr) | |
694 | { | |
695 | if (CHECK_ATTR(BPF_OBJ)) | |
696 | return -EINVAL; | |
697 | ||
698 | return bpf_obj_pin_user(attr->bpf_fd, u64_to_ptr(attr->pathname)); | |
699 | } | |
700 | ||
701 | static int bpf_obj_get(const union bpf_attr *attr) | |
702 | { | |
703 | if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0) | |
704 | return -EINVAL; | |
705 | ||
706 | return bpf_obj_get_user(u64_to_ptr(attr->pathname)); | |
707 | } | |
708 | ||
99c55f7d AS |
709 | SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) |
710 | { | |
711 | union bpf_attr attr = {}; | |
712 | int err; | |
713 | ||
1be7f75d | 714 | if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) |
99c55f7d AS |
715 | return -EPERM; |
716 | ||
717 | if (!access_ok(VERIFY_READ, uattr, 1)) | |
718 | return -EFAULT; | |
719 | ||
720 | if (size > PAGE_SIZE) /* silly large */ | |
721 | return -E2BIG; | |
722 | ||
723 | /* If we're handed a bigger struct than we know of, | |
724 | * ensure all the unknown bits are 0 - i.e. new | |
725 | * user-space does not rely on any kernel feature | |
726 | * extensions we dont know about yet. | |
727 | */ | |
728 | if (size > sizeof(attr)) { | |
729 | unsigned char __user *addr; | |
730 | unsigned char __user *end; | |
731 | unsigned char val; | |
732 | ||
733 | addr = (void __user *)uattr + sizeof(attr); | |
734 | end = (void __user *)uattr + size; | |
735 | ||
736 | for (; addr < end; addr++) { | |
737 | err = get_user(val, addr); | |
738 | if (err) | |
739 | return err; | |
740 | if (val) | |
741 | return -E2BIG; | |
742 | } | |
743 | size = sizeof(attr); | |
744 | } | |
745 | ||
746 | /* copy attributes from user space, may be less than sizeof(bpf_attr) */ | |
747 | if (copy_from_user(&attr, uattr, size) != 0) | |
748 | return -EFAULT; | |
749 | ||
750 | switch (cmd) { | |
751 | case BPF_MAP_CREATE: | |
752 | err = map_create(&attr); | |
753 | break; | |
db20fd2b AS |
754 | case BPF_MAP_LOOKUP_ELEM: |
755 | err = map_lookup_elem(&attr); | |
756 | break; | |
757 | case BPF_MAP_UPDATE_ELEM: | |
758 | err = map_update_elem(&attr); | |
759 | break; | |
760 | case BPF_MAP_DELETE_ELEM: | |
761 | err = map_delete_elem(&attr); | |
762 | break; | |
763 | case BPF_MAP_GET_NEXT_KEY: | |
764 | err = map_get_next_key(&attr); | |
765 | break; | |
09756af4 AS |
766 | case BPF_PROG_LOAD: |
767 | err = bpf_prog_load(&attr); | |
768 | break; | |
b2197755 DB |
769 | case BPF_OBJ_PIN: |
770 | err = bpf_obj_pin(&attr); | |
771 | break; | |
772 | case BPF_OBJ_GET: | |
773 | err = bpf_obj_get(&attr); | |
774 | break; | |
99c55f7d AS |
775 | default: |
776 | err = -EINVAL; | |
777 | break; | |
778 | } | |
779 | ||
780 | return err; | |
781 | } |