Commit | Line | Data |
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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 | ||
85 | /* decrement map refcnt and schedule it for freeing via workqueue | |
86 | * (unrelying map implementation ops->map_free() might sleep) | |
87 | */ | |
88 | void bpf_map_put(struct bpf_map *map) | |
89 | { | |
90 | if (atomic_dec_and_test(&map->refcnt)) { | |
91 | INIT_WORK(&map->work, bpf_map_free_deferred); | |
92 | schedule_work(&map->work); | |
93 | } | |
94 | } | |
95 | ||
96 | static int bpf_map_release(struct inode *inode, struct file *filp) | |
97 | { | |
98 | struct bpf_map *map = filp->private_data; | |
99 | ||
04fd61ab AS |
100 | if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) |
101 | /* prog_array stores refcnt-ed bpf_prog pointers | |
102 | * release them all when user space closes prog_array_fd | |
103 | */ | |
2a36f0b9 | 104 | bpf_fd_array_map_clear(map); |
04fd61ab | 105 | |
99c55f7d AS |
106 | bpf_map_put(map); |
107 | return 0; | |
108 | } | |
109 | ||
110 | static const struct file_operations bpf_map_fops = { | |
111 | .release = bpf_map_release, | |
112 | }; | |
113 | ||
b2197755 | 114 | int bpf_map_new_fd(struct bpf_map *map) |
aa79781b DB |
115 | { |
116 | return anon_inode_getfd("bpf-map", &bpf_map_fops, map, | |
117 | O_RDWR | O_CLOEXEC); | |
118 | } | |
119 | ||
99c55f7d AS |
120 | /* helper macro to check that unused fields 'union bpf_attr' are zero */ |
121 | #define CHECK_ATTR(CMD) \ | |
122 | memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ | |
123 | sizeof(attr->CMD##_LAST_FIELD), 0, \ | |
124 | sizeof(*attr) - \ | |
125 | offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ | |
126 | sizeof(attr->CMD##_LAST_FIELD)) != NULL | |
127 | ||
128 | #define BPF_MAP_CREATE_LAST_FIELD max_entries | |
129 | /* called via syscall */ | |
130 | static int map_create(union bpf_attr *attr) | |
131 | { | |
132 | struct bpf_map *map; | |
133 | int err; | |
134 | ||
135 | err = CHECK_ATTR(BPF_MAP_CREATE); | |
136 | if (err) | |
137 | return -EINVAL; | |
138 | ||
139 | /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ | |
140 | map = find_and_alloc_map(attr); | |
141 | if (IS_ERR(map)) | |
142 | return PTR_ERR(map); | |
143 | ||
144 | atomic_set(&map->refcnt, 1); | |
145 | ||
aaac3ba9 AS |
146 | err = bpf_map_charge_memlock(map); |
147 | if (err) | |
148 | goto free_map; | |
149 | ||
aa79781b | 150 | err = bpf_map_new_fd(map); |
99c55f7d AS |
151 | if (err < 0) |
152 | /* failed to allocate fd */ | |
153 | goto free_map; | |
154 | ||
155 | return err; | |
156 | ||
157 | free_map: | |
158 | map->ops->map_free(map); | |
159 | return err; | |
160 | } | |
161 | ||
db20fd2b AS |
162 | /* if error is returned, fd is released. |
163 | * On success caller should complete fd access with matching fdput() | |
164 | */ | |
c2101297 | 165 | struct bpf_map *__bpf_map_get(struct fd f) |
db20fd2b | 166 | { |
db20fd2b AS |
167 | if (!f.file) |
168 | return ERR_PTR(-EBADF); | |
db20fd2b AS |
169 | if (f.file->f_op != &bpf_map_fops) { |
170 | fdput(f); | |
171 | return ERR_PTR(-EINVAL); | |
172 | } | |
173 | ||
c2101297 DB |
174 | return f.file->private_data; |
175 | } | |
176 | ||
b2197755 | 177 | struct bpf_map *bpf_map_get(u32 ufd) |
c2101297 DB |
178 | { |
179 | struct fd f = fdget(ufd); | |
180 | struct bpf_map *map; | |
181 | ||
182 | map = __bpf_map_get(f); | |
183 | if (IS_ERR(map)) | |
184 | return map; | |
185 | ||
186 | atomic_inc(&map->refcnt); | |
187 | fdput(f); | |
db20fd2b AS |
188 | |
189 | return map; | |
190 | } | |
191 | ||
192 | /* helper to convert user pointers passed inside __aligned_u64 fields */ | |
193 | static void __user *u64_to_ptr(__u64 val) | |
194 | { | |
195 | return (void __user *) (unsigned long) val; | |
196 | } | |
197 | ||
198 | /* last field in 'union bpf_attr' used by this command */ | |
199 | #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value | |
200 | ||
201 | static int map_lookup_elem(union bpf_attr *attr) | |
202 | { | |
203 | void __user *ukey = u64_to_ptr(attr->key); | |
204 | void __user *uvalue = u64_to_ptr(attr->value); | |
205 | int ufd = attr->map_fd; | |
db20fd2b | 206 | struct bpf_map *map; |
8ebe667c | 207 | void *key, *value, *ptr; |
592867bf | 208 | struct fd f; |
db20fd2b AS |
209 | int err; |
210 | ||
211 | if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) | |
212 | return -EINVAL; | |
213 | ||
592867bf | 214 | f = fdget(ufd); |
c2101297 | 215 | map = __bpf_map_get(f); |
db20fd2b AS |
216 | if (IS_ERR(map)) |
217 | return PTR_ERR(map); | |
218 | ||
219 | err = -ENOMEM; | |
220 | key = kmalloc(map->key_size, GFP_USER); | |
221 | if (!key) | |
222 | goto err_put; | |
223 | ||
224 | err = -EFAULT; | |
225 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
226 | goto free_key; | |
227 | ||
8ebe667c AS |
228 | err = -ENOMEM; |
229 | value = kmalloc(map->value_size, GFP_USER); | |
db20fd2b | 230 | if (!value) |
8ebe667c AS |
231 | goto free_key; |
232 | ||
233 | rcu_read_lock(); | |
234 | ptr = map->ops->map_lookup_elem(map, key); | |
235 | if (ptr) | |
236 | memcpy(value, ptr, map->value_size); | |
237 | rcu_read_unlock(); | |
238 | ||
239 | err = -ENOENT; | |
240 | if (!ptr) | |
241 | goto free_value; | |
db20fd2b AS |
242 | |
243 | err = -EFAULT; | |
244 | if (copy_to_user(uvalue, value, map->value_size) != 0) | |
8ebe667c | 245 | goto free_value; |
db20fd2b AS |
246 | |
247 | err = 0; | |
248 | ||
8ebe667c AS |
249 | free_value: |
250 | kfree(value); | |
db20fd2b AS |
251 | free_key: |
252 | kfree(key); | |
253 | err_put: | |
254 | fdput(f); | |
255 | return err; | |
256 | } | |
257 | ||
3274f520 | 258 | #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags |
db20fd2b AS |
259 | |
260 | static int map_update_elem(union bpf_attr *attr) | |
261 | { | |
262 | void __user *ukey = u64_to_ptr(attr->key); | |
263 | void __user *uvalue = u64_to_ptr(attr->value); | |
264 | int ufd = attr->map_fd; | |
db20fd2b AS |
265 | struct bpf_map *map; |
266 | void *key, *value; | |
592867bf | 267 | struct fd f; |
db20fd2b AS |
268 | int err; |
269 | ||
270 | if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) | |
271 | return -EINVAL; | |
272 | ||
592867bf | 273 | f = fdget(ufd); |
c2101297 | 274 | map = __bpf_map_get(f); |
db20fd2b AS |
275 | if (IS_ERR(map)) |
276 | return PTR_ERR(map); | |
277 | ||
278 | err = -ENOMEM; | |
279 | key = kmalloc(map->key_size, GFP_USER); | |
280 | if (!key) | |
281 | goto err_put; | |
282 | ||
283 | err = -EFAULT; | |
284 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
285 | goto free_key; | |
286 | ||
287 | err = -ENOMEM; | |
288 | value = kmalloc(map->value_size, GFP_USER); | |
289 | if (!value) | |
290 | goto free_key; | |
291 | ||
292 | err = -EFAULT; | |
293 | if (copy_from_user(value, uvalue, map->value_size) != 0) | |
294 | goto free_value; | |
295 | ||
296 | /* eBPF program that use maps are running under rcu_read_lock(), | |
297 | * therefore all map accessors rely on this fact, so do the same here | |
298 | */ | |
299 | rcu_read_lock(); | |
3274f520 | 300 | err = map->ops->map_update_elem(map, key, value, attr->flags); |
db20fd2b AS |
301 | rcu_read_unlock(); |
302 | ||
303 | free_value: | |
304 | kfree(value); | |
305 | free_key: | |
306 | kfree(key); | |
307 | err_put: | |
308 | fdput(f); | |
309 | return err; | |
310 | } | |
311 | ||
312 | #define BPF_MAP_DELETE_ELEM_LAST_FIELD key | |
313 | ||
314 | static int map_delete_elem(union bpf_attr *attr) | |
315 | { | |
316 | void __user *ukey = u64_to_ptr(attr->key); | |
317 | int ufd = attr->map_fd; | |
db20fd2b | 318 | struct bpf_map *map; |
592867bf | 319 | struct fd f; |
db20fd2b AS |
320 | void *key; |
321 | int err; | |
322 | ||
323 | if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) | |
324 | return -EINVAL; | |
325 | ||
592867bf | 326 | f = fdget(ufd); |
c2101297 | 327 | map = __bpf_map_get(f); |
db20fd2b AS |
328 | if (IS_ERR(map)) |
329 | return PTR_ERR(map); | |
330 | ||
331 | err = -ENOMEM; | |
332 | key = kmalloc(map->key_size, GFP_USER); | |
333 | if (!key) | |
334 | goto err_put; | |
335 | ||
336 | err = -EFAULT; | |
337 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
338 | goto free_key; | |
339 | ||
340 | rcu_read_lock(); | |
341 | err = map->ops->map_delete_elem(map, key); | |
342 | rcu_read_unlock(); | |
343 | ||
344 | free_key: | |
345 | kfree(key); | |
346 | err_put: | |
347 | fdput(f); | |
348 | return err; | |
349 | } | |
350 | ||
351 | /* last field in 'union bpf_attr' used by this command */ | |
352 | #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key | |
353 | ||
354 | static int map_get_next_key(union bpf_attr *attr) | |
355 | { | |
356 | void __user *ukey = u64_to_ptr(attr->key); | |
357 | void __user *unext_key = u64_to_ptr(attr->next_key); | |
358 | int ufd = attr->map_fd; | |
db20fd2b AS |
359 | struct bpf_map *map; |
360 | void *key, *next_key; | |
592867bf | 361 | struct fd f; |
db20fd2b AS |
362 | int err; |
363 | ||
364 | if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) | |
365 | return -EINVAL; | |
366 | ||
592867bf | 367 | f = fdget(ufd); |
c2101297 | 368 | map = __bpf_map_get(f); |
db20fd2b AS |
369 | if (IS_ERR(map)) |
370 | return PTR_ERR(map); | |
371 | ||
372 | err = -ENOMEM; | |
373 | key = kmalloc(map->key_size, GFP_USER); | |
374 | if (!key) | |
375 | goto err_put; | |
376 | ||
377 | err = -EFAULT; | |
378 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
379 | goto free_key; | |
380 | ||
381 | err = -ENOMEM; | |
382 | next_key = kmalloc(map->key_size, GFP_USER); | |
383 | if (!next_key) | |
384 | goto free_key; | |
385 | ||
386 | rcu_read_lock(); | |
387 | err = map->ops->map_get_next_key(map, key, next_key); | |
388 | rcu_read_unlock(); | |
389 | if (err) | |
390 | goto free_next_key; | |
391 | ||
392 | err = -EFAULT; | |
393 | if (copy_to_user(unext_key, next_key, map->key_size) != 0) | |
394 | goto free_next_key; | |
395 | ||
396 | err = 0; | |
397 | ||
398 | free_next_key: | |
399 | kfree(next_key); | |
400 | free_key: | |
401 | kfree(key); | |
402 | err_put: | |
403 | fdput(f); | |
404 | return err; | |
405 | } | |
406 | ||
09756af4 AS |
407 | static LIST_HEAD(bpf_prog_types); |
408 | ||
409 | static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) | |
410 | { | |
411 | struct bpf_prog_type_list *tl; | |
412 | ||
413 | list_for_each_entry(tl, &bpf_prog_types, list_node) { | |
414 | if (tl->type == type) { | |
415 | prog->aux->ops = tl->ops; | |
24701ece | 416 | prog->type = type; |
09756af4 AS |
417 | return 0; |
418 | } | |
419 | } | |
24701ece | 420 | |
09756af4 AS |
421 | return -EINVAL; |
422 | } | |
423 | ||
424 | void bpf_register_prog_type(struct bpf_prog_type_list *tl) | |
425 | { | |
426 | list_add(&tl->list_node, &bpf_prog_types); | |
427 | } | |
428 | ||
0a542a86 AS |
429 | /* fixup insn->imm field of bpf_call instructions: |
430 | * if (insn->imm == BPF_FUNC_map_lookup_elem) | |
431 | * insn->imm = bpf_map_lookup_elem - __bpf_call_base; | |
432 | * else if (insn->imm == BPF_FUNC_map_update_elem) | |
433 | * insn->imm = bpf_map_update_elem - __bpf_call_base; | |
434 | * else ... | |
435 | * | |
436 | * this function is called after eBPF program passed verification | |
437 | */ | |
438 | static void fixup_bpf_calls(struct bpf_prog *prog) | |
439 | { | |
440 | const struct bpf_func_proto *fn; | |
441 | int i; | |
442 | ||
443 | for (i = 0; i < prog->len; i++) { | |
444 | struct bpf_insn *insn = &prog->insnsi[i]; | |
445 | ||
446 | if (insn->code == (BPF_JMP | BPF_CALL)) { | |
447 | /* we reach here when program has bpf_call instructions | |
448 | * and it passed bpf_check(), means that | |
449 | * ops->get_func_proto must have been supplied, check it | |
450 | */ | |
451 | BUG_ON(!prog->aux->ops->get_func_proto); | |
452 | ||
c46646d0 DB |
453 | if (insn->imm == BPF_FUNC_get_route_realm) |
454 | prog->dst_needed = 1; | |
3ad00405 DB |
455 | if (insn->imm == BPF_FUNC_get_prandom_u32) |
456 | bpf_user_rnd_init_once(); | |
04fd61ab AS |
457 | if (insn->imm == BPF_FUNC_tail_call) { |
458 | /* mark bpf_tail_call as different opcode | |
459 | * to avoid conditional branch in | |
460 | * interpeter for every normal call | |
461 | * and to prevent accidental JITing by | |
462 | * JIT compiler that doesn't support | |
463 | * bpf_tail_call yet | |
464 | */ | |
465 | insn->imm = 0; | |
466 | insn->code |= BPF_X; | |
467 | continue; | |
468 | } | |
469 | ||
0a542a86 AS |
470 | fn = prog->aux->ops->get_func_proto(insn->imm); |
471 | /* all functions that have prototype and verifier allowed | |
472 | * programs to call them, must be real in-kernel functions | |
473 | */ | |
474 | BUG_ON(!fn->func); | |
475 | insn->imm = fn->func - __bpf_call_base; | |
476 | } | |
477 | } | |
478 | } | |
479 | ||
09756af4 AS |
480 | /* drop refcnt on maps used by eBPF program and free auxilary data */ |
481 | static void free_used_maps(struct bpf_prog_aux *aux) | |
482 | { | |
483 | int i; | |
484 | ||
485 | for (i = 0; i < aux->used_map_cnt; i++) | |
486 | bpf_map_put(aux->used_maps[i]); | |
487 | ||
488 | kfree(aux->used_maps); | |
489 | } | |
490 | ||
aaac3ba9 AS |
491 | static int bpf_prog_charge_memlock(struct bpf_prog *prog) |
492 | { | |
493 | struct user_struct *user = get_current_user(); | |
494 | unsigned long memlock_limit; | |
495 | ||
496 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
497 | ||
498 | atomic_long_add(prog->pages, &user->locked_vm); | |
499 | if (atomic_long_read(&user->locked_vm) > memlock_limit) { | |
500 | atomic_long_sub(prog->pages, &user->locked_vm); | |
501 | free_uid(user); | |
502 | return -EPERM; | |
503 | } | |
504 | prog->aux->user = user; | |
505 | return 0; | |
506 | } | |
507 | ||
508 | static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) | |
509 | { | |
510 | struct user_struct *user = prog->aux->user; | |
511 | ||
512 | atomic_long_sub(prog->pages, &user->locked_vm); | |
513 | free_uid(user); | |
514 | } | |
515 | ||
e9d8afa9 | 516 | static void __prog_put_common(struct rcu_head *rcu) |
abf2e7d6 AS |
517 | { |
518 | struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); | |
519 | ||
520 | free_used_maps(aux); | |
aaac3ba9 | 521 | bpf_prog_uncharge_memlock(aux->prog); |
abf2e7d6 AS |
522 | bpf_prog_free(aux->prog); |
523 | } | |
524 | ||
525 | /* version of bpf_prog_put() that is called after a grace period */ | |
526 | void bpf_prog_put_rcu(struct bpf_prog *prog) | |
527 | { | |
e9d8afa9 DB |
528 | if (atomic_dec_and_test(&prog->aux->refcnt)) |
529 | call_rcu(&prog->aux->rcu, __prog_put_common); | |
abf2e7d6 AS |
530 | } |
531 | ||
09756af4 AS |
532 | void bpf_prog_put(struct bpf_prog *prog) |
533 | { | |
e9d8afa9 DB |
534 | if (atomic_dec_and_test(&prog->aux->refcnt)) |
535 | __prog_put_common(&prog->aux->rcu); | |
09756af4 | 536 | } |
e2e9b654 | 537 | EXPORT_SYMBOL_GPL(bpf_prog_put); |
09756af4 AS |
538 | |
539 | static int bpf_prog_release(struct inode *inode, struct file *filp) | |
540 | { | |
541 | struct bpf_prog *prog = filp->private_data; | |
542 | ||
abf2e7d6 | 543 | bpf_prog_put_rcu(prog); |
09756af4 AS |
544 | return 0; |
545 | } | |
546 | ||
547 | static const struct file_operations bpf_prog_fops = { | |
548 | .release = bpf_prog_release, | |
549 | }; | |
550 | ||
b2197755 | 551 | int bpf_prog_new_fd(struct bpf_prog *prog) |
aa79781b DB |
552 | { |
553 | return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, | |
554 | O_RDWR | O_CLOEXEC); | |
555 | } | |
556 | ||
c2101297 | 557 | static struct bpf_prog *__bpf_prog_get(struct fd f) |
09756af4 | 558 | { |
09756af4 AS |
559 | if (!f.file) |
560 | return ERR_PTR(-EBADF); | |
09756af4 AS |
561 | if (f.file->f_op != &bpf_prog_fops) { |
562 | fdput(f); | |
563 | return ERR_PTR(-EINVAL); | |
564 | } | |
565 | ||
c2101297 | 566 | return f.file->private_data; |
09756af4 AS |
567 | } |
568 | ||
569 | /* called by sockets/tracing/seccomp before attaching program to an event | |
570 | * pairs with bpf_prog_put() | |
571 | */ | |
572 | struct bpf_prog *bpf_prog_get(u32 ufd) | |
573 | { | |
574 | struct fd f = fdget(ufd); | |
575 | struct bpf_prog *prog; | |
576 | ||
c2101297 | 577 | prog = __bpf_prog_get(f); |
09756af4 AS |
578 | if (IS_ERR(prog)) |
579 | return prog; | |
580 | ||
581 | atomic_inc(&prog->aux->refcnt); | |
582 | fdput(f); | |
c2101297 | 583 | |
09756af4 AS |
584 | return prog; |
585 | } | |
e2e9b654 | 586 | EXPORT_SYMBOL_GPL(bpf_prog_get); |
09756af4 AS |
587 | |
588 | /* last field in 'union bpf_attr' used by this command */ | |
2541517c | 589 | #define BPF_PROG_LOAD_LAST_FIELD kern_version |
09756af4 AS |
590 | |
591 | static int bpf_prog_load(union bpf_attr *attr) | |
592 | { | |
593 | enum bpf_prog_type type = attr->prog_type; | |
594 | struct bpf_prog *prog; | |
595 | int err; | |
596 | char license[128]; | |
597 | bool is_gpl; | |
598 | ||
599 | if (CHECK_ATTR(BPF_PROG_LOAD)) | |
600 | return -EINVAL; | |
601 | ||
602 | /* copy eBPF program license from user space */ | |
603 | if (strncpy_from_user(license, u64_to_ptr(attr->license), | |
604 | sizeof(license) - 1) < 0) | |
605 | return -EFAULT; | |
606 | license[sizeof(license) - 1] = 0; | |
607 | ||
608 | /* eBPF programs must be GPL compatible to use GPL-ed functions */ | |
609 | is_gpl = license_is_gpl_compatible(license); | |
610 | ||
611 | if (attr->insn_cnt >= BPF_MAXINSNS) | |
612 | return -EINVAL; | |
613 | ||
2541517c AS |
614 | if (type == BPF_PROG_TYPE_KPROBE && |
615 | attr->kern_version != LINUX_VERSION_CODE) | |
616 | return -EINVAL; | |
617 | ||
1be7f75d AS |
618 | if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN)) |
619 | return -EPERM; | |
620 | ||
09756af4 AS |
621 | /* plain bpf_prog allocation */ |
622 | prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); | |
623 | if (!prog) | |
624 | return -ENOMEM; | |
625 | ||
aaac3ba9 AS |
626 | err = bpf_prog_charge_memlock(prog); |
627 | if (err) | |
628 | goto free_prog_nouncharge; | |
629 | ||
09756af4 AS |
630 | prog->len = attr->insn_cnt; |
631 | ||
632 | err = -EFAULT; | |
633 | if (copy_from_user(prog->insns, u64_to_ptr(attr->insns), | |
634 | prog->len * sizeof(struct bpf_insn)) != 0) | |
635 | goto free_prog; | |
636 | ||
637 | prog->orig_prog = NULL; | |
a91263d5 | 638 | prog->jited = 0; |
09756af4 AS |
639 | |
640 | atomic_set(&prog->aux->refcnt, 1); | |
a91263d5 | 641 | prog->gpl_compatible = is_gpl ? 1 : 0; |
09756af4 AS |
642 | |
643 | /* find program type: socket_filter vs tracing_filter */ | |
644 | err = find_prog_type(type, prog); | |
645 | if (err < 0) | |
646 | goto free_prog; | |
647 | ||
648 | /* run eBPF verifier */ | |
9bac3d6d | 649 | err = bpf_check(&prog, attr); |
09756af4 AS |
650 | if (err < 0) |
651 | goto free_used_maps; | |
652 | ||
0a542a86 AS |
653 | /* fixup BPF_CALL->imm field */ |
654 | fixup_bpf_calls(prog); | |
655 | ||
09756af4 | 656 | /* eBPF program is ready to be JITed */ |
04fd61ab AS |
657 | err = bpf_prog_select_runtime(prog); |
658 | if (err < 0) | |
659 | goto free_used_maps; | |
09756af4 | 660 | |
aa79781b | 661 | err = bpf_prog_new_fd(prog); |
09756af4 AS |
662 | if (err < 0) |
663 | /* failed to allocate fd */ | |
664 | goto free_used_maps; | |
665 | ||
666 | return err; | |
667 | ||
668 | free_used_maps: | |
669 | free_used_maps(prog->aux); | |
670 | free_prog: | |
aaac3ba9 AS |
671 | bpf_prog_uncharge_memlock(prog); |
672 | free_prog_nouncharge: | |
09756af4 AS |
673 | bpf_prog_free(prog); |
674 | return err; | |
675 | } | |
676 | ||
b2197755 DB |
677 | #define BPF_OBJ_LAST_FIELD bpf_fd |
678 | ||
679 | static int bpf_obj_pin(const union bpf_attr *attr) | |
680 | { | |
681 | if (CHECK_ATTR(BPF_OBJ)) | |
682 | return -EINVAL; | |
683 | ||
684 | return bpf_obj_pin_user(attr->bpf_fd, u64_to_ptr(attr->pathname)); | |
685 | } | |
686 | ||
687 | static int bpf_obj_get(const union bpf_attr *attr) | |
688 | { | |
689 | if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0) | |
690 | return -EINVAL; | |
691 | ||
692 | return bpf_obj_get_user(u64_to_ptr(attr->pathname)); | |
693 | } | |
694 | ||
99c55f7d AS |
695 | SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) |
696 | { | |
697 | union bpf_attr attr = {}; | |
698 | int err; | |
699 | ||
1be7f75d | 700 | if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) |
99c55f7d AS |
701 | return -EPERM; |
702 | ||
703 | if (!access_ok(VERIFY_READ, uattr, 1)) | |
704 | return -EFAULT; | |
705 | ||
706 | if (size > PAGE_SIZE) /* silly large */ | |
707 | return -E2BIG; | |
708 | ||
709 | /* If we're handed a bigger struct than we know of, | |
710 | * ensure all the unknown bits are 0 - i.e. new | |
711 | * user-space does not rely on any kernel feature | |
712 | * extensions we dont know about yet. | |
713 | */ | |
714 | if (size > sizeof(attr)) { | |
715 | unsigned char __user *addr; | |
716 | unsigned char __user *end; | |
717 | unsigned char val; | |
718 | ||
719 | addr = (void __user *)uattr + sizeof(attr); | |
720 | end = (void __user *)uattr + size; | |
721 | ||
722 | for (; addr < end; addr++) { | |
723 | err = get_user(val, addr); | |
724 | if (err) | |
725 | return err; | |
726 | if (val) | |
727 | return -E2BIG; | |
728 | } | |
729 | size = sizeof(attr); | |
730 | } | |
731 | ||
732 | /* copy attributes from user space, may be less than sizeof(bpf_attr) */ | |
733 | if (copy_from_user(&attr, uattr, size) != 0) | |
734 | return -EFAULT; | |
735 | ||
736 | switch (cmd) { | |
737 | case BPF_MAP_CREATE: | |
738 | err = map_create(&attr); | |
739 | break; | |
db20fd2b AS |
740 | case BPF_MAP_LOOKUP_ELEM: |
741 | err = map_lookup_elem(&attr); | |
742 | break; | |
743 | case BPF_MAP_UPDATE_ELEM: | |
744 | err = map_update_elem(&attr); | |
745 | break; | |
746 | case BPF_MAP_DELETE_ELEM: | |
747 | err = map_delete_elem(&attr); | |
748 | break; | |
749 | case BPF_MAP_GET_NEXT_KEY: | |
750 | err = map_get_next_key(&attr); | |
751 | break; | |
09756af4 AS |
752 | case BPF_PROG_LOAD: |
753 | err = bpf_prog_load(&attr); | |
754 | break; | |
b2197755 DB |
755 | case BPF_OBJ_PIN: |
756 | err = bpf_obj_pin(&attr); | |
757 | break; | |
758 | case BPF_OBJ_GET: | |
759 | err = bpf_obj_get(&attr); | |
760 | break; | |
99c55f7d AS |
761 | default: |
762 | err = -EINVAL; | |
763 | break; | |
764 | } | |
765 | ||
766 | return err; | |
767 | } |