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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> |
535e7b4b | 20 | #include <linux/kernel.h> |
99c55f7d | 21 | |
b121d1e7 AS |
22 | DEFINE_PER_CPU(int, bpf_prog_active); |
23 | ||
1be7f75d AS |
24 | int sysctl_unprivileged_bpf_disabled __read_mostly; |
25 | ||
99c55f7d AS |
26 | static LIST_HEAD(bpf_map_types); |
27 | ||
28 | static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) | |
29 | { | |
30 | struct bpf_map_type_list *tl; | |
31 | struct bpf_map *map; | |
32 | ||
33 | list_for_each_entry(tl, &bpf_map_types, list_node) { | |
34 | if (tl->type == attr->map_type) { | |
35 | map = tl->ops->map_alloc(attr); | |
36 | if (IS_ERR(map)) | |
37 | return map; | |
38 | map->ops = tl->ops; | |
39 | map->map_type = attr->map_type; | |
40 | return map; | |
41 | } | |
42 | } | |
43 | return ERR_PTR(-EINVAL); | |
44 | } | |
45 | ||
46 | /* boot time registration of different map implementations */ | |
47 | void bpf_register_map_type(struct bpf_map_type_list *tl) | |
48 | { | |
49 | list_add(&tl->list_node, &bpf_map_types); | |
50 | } | |
51 | ||
6c905981 AS |
52 | int bpf_map_precharge_memlock(u32 pages) |
53 | { | |
54 | struct user_struct *user = get_current_user(); | |
55 | unsigned long memlock_limit, cur; | |
56 | ||
57 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
58 | cur = atomic_long_read(&user->locked_vm); | |
59 | free_uid(user); | |
60 | if (cur + pages > memlock_limit) | |
61 | return -EPERM; | |
62 | return 0; | |
63 | } | |
64 | ||
aaac3ba9 AS |
65 | static int bpf_map_charge_memlock(struct bpf_map *map) |
66 | { | |
67 | struct user_struct *user = get_current_user(); | |
68 | unsigned long memlock_limit; | |
69 | ||
70 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
71 | ||
72 | atomic_long_add(map->pages, &user->locked_vm); | |
73 | ||
74 | if (atomic_long_read(&user->locked_vm) > memlock_limit) { | |
75 | atomic_long_sub(map->pages, &user->locked_vm); | |
76 | free_uid(user); | |
77 | return -EPERM; | |
78 | } | |
79 | map->user = user; | |
80 | return 0; | |
81 | } | |
82 | ||
83 | static void bpf_map_uncharge_memlock(struct bpf_map *map) | |
84 | { | |
85 | struct user_struct *user = map->user; | |
86 | ||
87 | atomic_long_sub(map->pages, &user->locked_vm); | |
88 | free_uid(user); | |
89 | } | |
90 | ||
99c55f7d AS |
91 | /* called from workqueue */ |
92 | static void bpf_map_free_deferred(struct work_struct *work) | |
93 | { | |
94 | struct bpf_map *map = container_of(work, struct bpf_map, work); | |
95 | ||
aaac3ba9 | 96 | bpf_map_uncharge_memlock(map); |
99c55f7d AS |
97 | /* implementation dependent freeing */ |
98 | map->ops->map_free(map); | |
99 | } | |
100 | ||
c9da161c DB |
101 | static void bpf_map_put_uref(struct bpf_map *map) |
102 | { | |
103 | if (atomic_dec_and_test(&map->usercnt)) { | |
104 | if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) | |
105 | bpf_fd_array_map_clear(map); | |
106 | } | |
107 | } | |
108 | ||
99c55f7d AS |
109 | /* decrement map refcnt and schedule it for freeing via workqueue |
110 | * (unrelying map implementation ops->map_free() might sleep) | |
111 | */ | |
112 | void bpf_map_put(struct bpf_map *map) | |
113 | { | |
114 | if (atomic_dec_and_test(&map->refcnt)) { | |
115 | INIT_WORK(&map->work, bpf_map_free_deferred); | |
116 | schedule_work(&map->work); | |
117 | } | |
118 | } | |
119 | ||
c9da161c | 120 | void bpf_map_put_with_uref(struct bpf_map *map) |
99c55f7d | 121 | { |
c9da161c | 122 | bpf_map_put_uref(map); |
99c55f7d | 123 | bpf_map_put(map); |
c9da161c DB |
124 | } |
125 | ||
126 | static int bpf_map_release(struct inode *inode, struct file *filp) | |
127 | { | |
61d1b6a4 DB |
128 | struct bpf_map *map = filp->private_data; |
129 | ||
130 | if (map->ops->map_release) | |
131 | map->ops->map_release(map, filp); | |
132 | ||
133 | bpf_map_put_with_uref(map); | |
99c55f7d AS |
134 | return 0; |
135 | } | |
136 | ||
f99bf205 DB |
137 | #ifdef CONFIG_PROC_FS |
138 | static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) | |
139 | { | |
140 | const struct bpf_map *map = filp->private_data; | |
21116b70 DB |
141 | const struct bpf_array *array; |
142 | u32 owner_prog_type = 0; | |
143 | ||
144 | if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { | |
145 | array = container_of(map, struct bpf_array, map); | |
146 | owner_prog_type = array->owner_prog_type; | |
147 | } | |
f99bf205 DB |
148 | |
149 | seq_printf(m, | |
150 | "map_type:\t%u\n" | |
151 | "key_size:\t%u\n" | |
152 | "value_size:\t%u\n" | |
322cea2f | 153 | "max_entries:\t%u\n" |
21116b70 DB |
154 | "map_flags:\t%#x\n" |
155 | "memlock:\t%llu\n", | |
f99bf205 DB |
156 | map->map_type, |
157 | map->key_size, | |
158 | map->value_size, | |
322cea2f | 159 | map->max_entries, |
21116b70 DB |
160 | map->map_flags, |
161 | map->pages * 1ULL << PAGE_SHIFT); | |
162 | ||
163 | if (owner_prog_type) | |
164 | seq_printf(m, "owner_prog_type:\t%u\n", | |
165 | owner_prog_type); | |
f99bf205 DB |
166 | } |
167 | #endif | |
168 | ||
99c55f7d | 169 | static const struct file_operations bpf_map_fops = { |
f99bf205 DB |
170 | #ifdef CONFIG_PROC_FS |
171 | .show_fdinfo = bpf_map_show_fdinfo, | |
172 | #endif | |
173 | .release = bpf_map_release, | |
99c55f7d AS |
174 | }; |
175 | ||
b2197755 | 176 | int bpf_map_new_fd(struct bpf_map *map) |
aa79781b DB |
177 | { |
178 | return anon_inode_getfd("bpf-map", &bpf_map_fops, map, | |
179 | O_RDWR | O_CLOEXEC); | |
180 | } | |
181 | ||
99c55f7d AS |
182 | /* helper macro to check that unused fields 'union bpf_attr' are zero */ |
183 | #define CHECK_ATTR(CMD) \ | |
184 | memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ | |
185 | sizeof(attr->CMD##_LAST_FIELD), 0, \ | |
186 | sizeof(*attr) - \ | |
187 | offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ | |
188 | sizeof(attr->CMD##_LAST_FIELD)) != NULL | |
189 | ||
6c905981 | 190 | #define BPF_MAP_CREATE_LAST_FIELD map_flags |
99c55f7d AS |
191 | /* called via syscall */ |
192 | static int map_create(union bpf_attr *attr) | |
193 | { | |
194 | struct bpf_map *map; | |
195 | int err; | |
196 | ||
197 | err = CHECK_ATTR(BPF_MAP_CREATE); | |
198 | if (err) | |
199 | return -EINVAL; | |
200 | ||
201 | /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ | |
202 | map = find_and_alloc_map(attr); | |
203 | if (IS_ERR(map)) | |
204 | return PTR_ERR(map); | |
205 | ||
206 | atomic_set(&map->refcnt, 1); | |
c9da161c | 207 | atomic_set(&map->usercnt, 1); |
99c55f7d | 208 | |
aaac3ba9 AS |
209 | err = bpf_map_charge_memlock(map); |
210 | if (err) | |
20b2b24f | 211 | goto free_map_nouncharge; |
aaac3ba9 | 212 | |
aa79781b | 213 | err = bpf_map_new_fd(map); |
99c55f7d AS |
214 | if (err < 0) |
215 | /* failed to allocate fd */ | |
216 | goto free_map; | |
217 | ||
218 | return err; | |
219 | ||
220 | free_map: | |
20b2b24f DB |
221 | bpf_map_uncharge_memlock(map); |
222 | free_map_nouncharge: | |
99c55f7d AS |
223 | map->ops->map_free(map); |
224 | return err; | |
225 | } | |
226 | ||
db20fd2b AS |
227 | /* if error is returned, fd is released. |
228 | * On success caller should complete fd access with matching fdput() | |
229 | */ | |
c2101297 | 230 | struct bpf_map *__bpf_map_get(struct fd f) |
db20fd2b | 231 | { |
db20fd2b AS |
232 | if (!f.file) |
233 | return ERR_PTR(-EBADF); | |
db20fd2b AS |
234 | if (f.file->f_op != &bpf_map_fops) { |
235 | fdput(f); | |
236 | return ERR_PTR(-EINVAL); | |
237 | } | |
238 | ||
c2101297 DB |
239 | return f.file->private_data; |
240 | } | |
241 | ||
92117d84 AS |
242 | /* prog's and map's refcnt limit */ |
243 | #define BPF_MAX_REFCNT 32768 | |
244 | ||
245 | struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref) | |
c9da161c | 246 | { |
92117d84 AS |
247 | if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) { |
248 | atomic_dec(&map->refcnt); | |
249 | return ERR_PTR(-EBUSY); | |
250 | } | |
c9da161c DB |
251 | if (uref) |
252 | atomic_inc(&map->usercnt); | |
92117d84 | 253 | return map; |
c9da161c DB |
254 | } |
255 | ||
256 | struct bpf_map *bpf_map_get_with_uref(u32 ufd) | |
c2101297 DB |
257 | { |
258 | struct fd f = fdget(ufd); | |
259 | struct bpf_map *map; | |
260 | ||
261 | map = __bpf_map_get(f); | |
262 | if (IS_ERR(map)) | |
263 | return map; | |
264 | ||
92117d84 | 265 | map = bpf_map_inc(map, true); |
c2101297 | 266 | fdput(f); |
db20fd2b AS |
267 | |
268 | return map; | |
269 | } | |
270 | ||
b8cdc051 AS |
271 | int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) |
272 | { | |
273 | return -ENOTSUPP; | |
274 | } | |
275 | ||
db20fd2b AS |
276 | /* last field in 'union bpf_attr' used by this command */ |
277 | #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value | |
278 | ||
279 | static int map_lookup_elem(union bpf_attr *attr) | |
280 | { | |
535e7b4b MS |
281 | void __user *ukey = u64_to_user_ptr(attr->key); |
282 | void __user *uvalue = u64_to_user_ptr(attr->value); | |
db20fd2b | 283 | int ufd = attr->map_fd; |
db20fd2b | 284 | struct bpf_map *map; |
8ebe667c | 285 | void *key, *value, *ptr; |
15a07b33 | 286 | u32 value_size; |
592867bf | 287 | struct fd f; |
db20fd2b AS |
288 | int err; |
289 | ||
290 | if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) | |
291 | return -EINVAL; | |
292 | ||
592867bf | 293 | f = fdget(ufd); |
c2101297 | 294 | map = __bpf_map_get(f); |
db20fd2b AS |
295 | if (IS_ERR(map)) |
296 | return PTR_ERR(map); | |
297 | ||
298 | err = -ENOMEM; | |
299 | key = kmalloc(map->key_size, GFP_USER); | |
300 | if (!key) | |
301 | goto err_put; | |
302 | ||
303 | err = -EFAULT; | |
304 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
305 | goto free_key; | |
306 | ||
15a07b33 | 307 | if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
8f844938 | 308 | map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || |
15a07b33 AS |
309 | map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
310 | value_size = round_up(map->value_size, 8) * num_possible_cpus(); | |
311 | else | |
312 | value_size = map->value_size; | |
313 | ||
8ebe667c | 314 | err = -ENOMEM; |
15a07b33 | 315 | value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); |
db20fd2b | 316 | if (!value) |
8ebe667c AS |
317 | goto free_key; |
318 | ||
8f844938 MKL |
319 | if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
320 | map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { | |
15a07b33 AS |
321 | err = bpf_percpu_hash_copy(map, key, value); |
322 | } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { | |
323 | err = bpf_percpu_array_copy(map, key, value); | |
557c0c6e AS |
324 | } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { |
325 | err = bpf_stackmap_copy(map, key, value); | |
15a07b33 AS |
326 | } else { |
327 | rcu_read_lock(); | |
328 | ptr = map->ops->map_lookup_elem(map, key); | |
329 | if (ptr) | |
330 | memcpy(value, ptr, value_size); | |
331 | rcu_read_unlock(); | |
332 | err = ptr ? 0 : -ENOENT; | |
333 | } | |
8ebe667c | 334 | |
15a07b33 | 335 | if (err) |
8ebe667c | 336 | goto free_value; |
db20fd2b AS |
337 | |
338 | err = -EFAULT; | |
15a07b33 | 339 | if (copy_to_user(uvalue, value, value_size) != 0) |
8ebe667c | 340 | goto free_value; |
db20fd2b AS |
341 | |
342 | err = 0; | |
343 | ||
8ebe667c AS |
344 | free_value: |
345 | kfree(value); | |
db20fd2b AS |
346 | free_key: |
347 | kfree(key); | |
348 | err_put: | |
349 | fdput(f); | |
350 | return err; | |
351 | } | |
352 | ||
3274f520 | 353 | #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags |
db20fd2b AS |
354 | |
355 | static int map_update_elem(union bpf_attr *attr) | |
356 | { | |
535e7b4b MS |
357 | void __user *ukey = u64_to_user_ptr(attr->key); |
358 | void __user *uvalue = u64_to_user_ptr(attr->value); | |
db20fd2b | 359 | int ufd = attr->map_fd; |
db20fd2b AS |
360 | struct bpf_map *map; |
361 | void *key, *value; | |
15a07b33 | 362 | u32 value_size; |
592867bf | 363 | struct fd f; |
db20fd2b AS |
364 | int err; |
365 | ||
366 | if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) | |
367 | return -EINVAL; | |
368 | ||
592867bf | 369 | f = fdget(ufd); |
c2101297 | 370 | map = __bpf_map_get(f); |
db20fd2b AS |
371 | if (IS_ERR(map)) |
372 | return PTR_ERR(map); | |
373 | ||
374 | err = -ENOMEM; | |
375 | key = kmalloc(map->key_size, GFP_USER); | |
376 | if (!key) | |
377 | goto err_put; | |
378 | ||
379 | err = -EFAULT; | |
380 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
381 | goto free_key; | |
382 | ||
15a07b33 | 383 | if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
8f844938 | 384 | map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || |
15a07b33 AS |
385 | map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
386 | value_size = round_up(map->value_size, 8) * num_possible_cpus(); | |
387 | else | |
388 | value_size = map->value_size; | |
389 | ||
db20fd2b | 390 | err = -ENOMEM; |
15a07b33 | 391 | value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); |
db20fd2b AS |
392 | if (!value) |
393 | goto free_key; | |
394 | ||
395 | err = -EFAULT; | |
15a07b33 | 396 | if (copy_from_user(value, uvalue, value_size) != 0) |
db20fd2b AS |
397 | goto free_value; |
398 | ||
b121d1e7 AS |
399 | /* must increment bpf_prog_active to avoid kprobe+bpf triggering from |
400 | * inside bpf map update or delete otherwise deadlocks are possible | |
401 | */ | |
402 | preempt_disable(); | |
403 | __this_cpu_inc(bpf_prog_active); | |
8f844938 MKL |
404 | if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
405 | map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { | |
15a07b33 AS |
406 | err = bpf_percpu_hash_update(map, key, value, attr->flags); |
407 | } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { | |
408 | err = bpf_percpu_array_update(map, key, value, attr->flags); | |
d056a788 | 409 | } else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || |
4ed8ec52 MKL |
410 | map->map_type == BPF_MAP_TYPE_PROG_ARRAY || |
411 | map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY) { | |
d056a788 DB |
412 | rcu_read_lock(); |
413 | err = bpf_fd_array_map_update_elem(map, f.file, key, value, | |
414 | attr->flags); | |
415 | rcu_read_unlock(); | |
15a07b33 AS |
416 | } else { |
417 | rcu_read_lock(); | |
418 | err = map->ops->map_update_elem(map, key, value, attr->flags); | |
419 | rcu_read_unlock(); | |
420 | } | |
b121d1e7 AS |
421 | __this_cpu_dec(bpf_prog_active); |
422 | preempt_enable(); | |
db20fd2b AS |
423 | |
424 | free_value: | |
425 | kfree(value); | |
426 | free_key: | |
427 | kfree(key); | |
428 | err_put: | |
429 | fdput(f); | |
430 | return err; | |
431 | } | |
432 | ||
433 | #define BPF_MAP_DELETE_ELEM_LAST_FIELD key | |
434 | ||
435 | static int map_delete_elem(union bpf_attr *attr) | |
436 | { | |
535e7b4b | 437 | void __user *ukey = u64_to_user_ptr(attr->key); |
db20fd2b | 438 | int ufd = attr->map_fd; |
db20fd2b | 439 | struct bpf_map *map; |
592867bf | 440 | struct fd f; |
db20fd2b AS |
441 | void *key; |
442 | int err; | |
443 | ||
444 | if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) | |
445 | return -EINVAL; | |
446 | ||
592867bf | 447 | f = fdget(ufd); |
c2101297 | 448 | map = __bpf_map_get(f); |
db20fd2b AS |
449 | if (IS_ERR(map)) |
450 | return PTR_ERR(map); | |
451 | ||
452 | err = -ENOMEM; | |
453 | key = kmalloc(map->key_size, GFP_USER); | |
454 | if (!key) | |
455 | goto err_put; | |
456 | ||
457 | err = -EFAULT; | |
458 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
459 | goto free_key; | |
460 | ||
b121d1e7 AS |
461 | preempt_disable(); |
462 | __this_cpu_inc(bpf_prog_active); | |
db20fd2b AS |
463 | rcu_read_lock(); |
464 | err = map->ops->map_delete_elem(map, key); | |
465 | rcu_read_unlock(); | |
b121d1e7 AS |
466 | __this_cpu_dec(bpf_prog_active); |
467 | preempt_enable(); | |
db20fd2b AS |
468 | |
469 | free_key: | |
470 | kfree(key); | |
471 | err_put: | |
472 | fdput(f); | |
473 | return err; | |
474 | } | |
475 | ||
476 | /* last field in 'union bpf_attr' used by this command */ | |
477 | #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key | |
478 | ||
479 | static int map_get_next_key(union bpf_attr *attr) | |
480 | { | |
535e7b4b MS |
481 | void __user *ukey = u64_to_user_ptr(attr->key); |
482 | void __user *unext_key = u64_to_user_ptr(attr->next_key); | |
db20fd2b | 483 | int ufd = attr->map_fd; |
db20fd2b AS |
484 | struct bpf_map *map; |
485 | void *key, *next_key; | |
592867bf | 486 | struct fd f; |
db20fd2b AS |
487 | int err; |
488 | ||
489 | if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) | |
490 | return -EINVAL; | |
491 | ||
592867bf | 492 | f = fdget(ufd); |
c2101297 | 493 | map = __bpf_map_get(f); |
db20fd2b AS |
494 | if (IS_ERR(map)) |
495 | return PTR_ERR(map); | |
496 | ||
497 | err = -ENOMEM; | |
498 | key = kmalloc(map->key_size, GFP_USER); | |
499 | if (!key) | |
500 | goto err_put; | |
501 | ||
502 | err = -EFAULT; | |
503 | if (copy_from_user(key, ukey, map->key_size) != 0) | |
504 | goto free_key; | |
505 | ||
506 | err = -ENOMEM; | |
507 | next_key = kmalloc(map->key_size, GFP_USER); | |
508 | if (!next_key) | |
509 | goto free_key; | |
510 | ||
511 | rcu_read_lock(); | |
512 | err = map->ops->map_get_next_key(map, key, next_key); | |
513 | rcu_read_unlock(); | |
514 | if (err) | |
515 | goto free_next_key; | |
516 | ||
517 | err = -EFAULT; | |
518 | if (copy_to_user(unext_key, next_key, map->key_size) != 0) | |
519 | goto free_next_key; | |
520 | ||
521 | err = 0; | |
522 | ||
523 | free_next_key: | |
524 | kfree(next_key); | |
525 | free_key: | |
526 | kfree(key); | |
527 | err_put: | |
528 | fdput(f); | |
529 | return err; | |
530 | } | |
531 | ||
09756af4 AS |
532 | static LIST_HEAD(bpf_prog_types); |
533 | ||
534 | static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) | |
535 | { | |
536 | struct bpf_prog_type_list *tl; | |
537 | ||
538 | list_for_each_entry(tl, &bpf_prog_types, list_node) { | |
539 | if (tl->type == type) { | |
540 | prog->aux->ops = tl->ops; | |
24701ece | 541 | prog->type = type; |
09756af4 AS |
542 | return 0; |
543 | } | |
544 | } | |
24701ece | 545 | |
09756af4 AS |
546 | return -EINVAL; |
547 | } | |
548 | ||
549 | void bpf_register_prog_type(struct bpf_prog_type_list *tl) | |
550 | { | |
551 | list_add(&tl->list_node, &bpf_prog_types); | |
552 | } | |
553 | ||
0a542a86 AS |
554 | /* fixup insn->imm field of bpf_call instructions: |
555 | * if (insn->imm == BPF_FUNC_map_lookup_elem) | |
556 | * insn->imm = bpf_map_lookup_elem - __bpf_call_base; | |
557 | * else if (insn->imm == BPF_FUNC_map_update_elem) | |
558 | * insn->imm = bpf_map_update_elem - __bpf_call_base; | |
559 | * else ... | |
560 | * | |
561 | * this function is called after eBPF program passed verification | |
562 | */ | |
563 | static void fixup_bpf_calls(struct bpf_prog *prog) | |
564 | { | |
565 | const struct bpf_func_proto *fn; | |
566 | int i; | |
567 | ||
568 | for (i = 0; i < prog->len; i++) { | |
569 | struct bpf_insn *insn = &prog->insnsi[i]; | |
570 | ||
571 | if (insn->code == (BPF_JMP | BPF_CALL)) { | |
572 | /* we reach here when program has bpf_call instructions | |
573 | * and it passed bpf_check(), means that | |
574 | * ops->get_func_proto must have been supplied, check it | |
575 | */ | |
576 | BUG_ON(!prog->aux->ops->get_func_proto); | |
577 | ||
c46646d0 DB |
578 | if (insn->imm == BPF_FUNC_get_route_realm) |
579 | prog->dst_needed = 1; | |
3ad00405 DB |
580 | if (insn->imm == BPF_FUNC_get_prandom_u32) |
581 | bpf_user_rnd_init_once(); | |
17bedab2 MKL |
582 | if (insn->imm == BPF_FUNC_xdp_adjust_head) |
583 | prog->xdp_adjust_head = 1; | |
04fd61ab AS |
584 | if (insn->imm == BPF_FUNC_tail_call) { |
585 | /* mark bpf_tail_call as different opcode | |
586 | * to avoid conditional branch in | |
587 | * interpeter for every normal call | |
588 | * and to prevent accidental JITing by | |
589 | * JIT compiler that doesn't support | |
590 | * bpf_tail_call yet | |
591 | */ | |
592 | insn->imm = 0; | |
593 | insn->code |= BPF_X; | |
594 | continue; | |
595 | } | |
596 | ||
0a542a86 AS |
597 | fn = prog->aux->ops->get_func_proto(insn->imm); |
598 | /* all functions that have prototype and verifier allowed | |
599 | * programs to call them, must be real in-kernel functions | |
600 | */ | |
601 | BUG_ON(!fn->func); | |
602 | insn->imm = fn->func - __bpf_call_base; | |
603 | } | |
604 | } | |
605 | } | |
606 | ||
09756af4 AS |
607 | /* drop refcnt on maps used by eBPF program and free auxilary data */ |
608 | static void free_used_maps(struct bpf_prog_aux *aux) | |
609 | { | |
610 | int i; | |
611 | ||
612 | for (i = 0; i < aux->used_map_cnt; i++) | |
613 | bpf_map_put(aux->used_maps[i]); | |
614 | ||
615 | kfree(aux->used_maps); | |
616 | } | |
617 | ||
aaac3ba9 AS |
618 | static int bpf_prog_charge_memlock(struct bpf_prog *prog) |
619 | { | |
620 | struct user_struct *user = get_current_user(); | |
621 | unsigned long memlock_limit; | |
622 | ||
623 | memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
624 | ||
625 | atomic_long_add(prog->pages, &user->locked_vm); | |
626 | if (atomic_long_read(&user->locked_vm) > memlock_limit) { | |
627 | atomic_long_sub(prog->pages, &user->locked_vm); | |
628 | free_uid(user); | |
629 | return -EPERM; | |
630 | } | |
631 | prog->aux->user = user; | |
632 | return 0; | |
633 | } | |
634 | ||
635 | static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) | |
636 | { | |
637 | struct user_struct *user = prog->aux->user; | |
638 | ||
639 | atomic_long_sub(prog->pages, &user->locked_vm); | |
640 | free_uid(user); | |
641 | } | |
642 | ||
1aacde3d | 643 | static void __bpf_prog_put_rcu(struct rcu_head *rcu) |
abf2e7d6 AS |
644 | { |
645 | struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); | |
646 | ||
647 | free_used_maps(aux); | |
aaac3ba9 | 648 | bpf_prog_uncharge_memlock(aux->prog); |
abf2e7d6 AS |
649 | bpf_prog_free(aux->prog); |
650 | } | |
651 | ||
09756af4 AS |
652 | void bpf_prog_put(struct bpf_prog *prog) |
653 | { | |
e9d8afa9 | 654 | if (atomic_dec_and_test(&prog->aux->refcnt)) |
1aacde3d | 655 | call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); |
09756af4 | 656 | } |
e2e9b654 | 657 | EXPORT_SYMBOL_GPL(bpf_prog_put); |
09756af4 AS |
658 | |
659 | static int bpf_prog_release(struct inode *inode, struct file *filp) | |
660 | { | |
661 | struct bpf_prog *prog = filp->private_data; | |
662 | ||
1aacde3d | 663 | bpf_prog_put(prog); |
09756af4 AS |
664 | return 0; |
665 | } | |
666 | ||
7bd509e3 DB |
667 | #ifdef CONFIG_PROC_FS |
668 | static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) | |
669 | { | |
670 | const struct bpf_prog *prog = filp->private_data; | |
671 | char prog_digest[sizeof(prog->digest) * 2 + 1] = { }; | |
672 | ||
673 | bin2hex(prog_digest, prog->digest, sizeof(prog->digest)); | |
674 | seq_printf(m, | |
675 | "prog_type:\t%u\n" | |
676 | "prog_jited:\t%u\n" | |
677 | "prog_digest:\t%s\n" | |
678 | "memlock:\t%llu\n", | |
679 | prog->type, | |
680 | prog->jited, | |
681 | prog_digest, | |
682 | prog->pages * 1ULL << PAGE_SHIFT); | |
683 | } | |
684 | #endif | |
685 | ||
09756af4 | 686 | static const struct file_operations bpf_prog_fops = { |
7bd509e3 DB |
687 | #ifdef CONFIG_PROC_FS |
688 | .show_fdinfo = bpf_prog_show_fdinfo, | |
689 | #endif | |
690 | .release = bpf_prog_release, | |
09756af4 AS |
691 | }; |
692 | ||
b2197755 | 693 | int bpf_prog_new_fd(struct bpf_prog *prog) |
aa79781b DB |
694 | { |
695 | return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, | |
696 | O_RDWR | O_CLOEXEC); | |
697 | } | |
698 | ||
113214be | 699 | static struct bpf_prog *____bpf_prog_get(struct fd f) |
09756af4 | 700 | { |
09756af4 AS |
701 | if (!f.file) |
702 | return ERR_PTR(-EBADF); | |
09756af4 AS |
703 | if (f.file->f_op != &bpf_prog_fops) { |
704 | fdput(f); | |
705 | return ERR_PTR(-EINVAL); | |
706 | } | |
707 | ||
c2101297 | 708 | return f.file->private_data; |
09756af4 AS |
709 | } |
710 | ||
59d3656d | 711 | struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i) |
92117d84 | 712 | { |
59d3656d BB |
713 | if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) { |
714 | atomic_sub(i, &prog->aux->refcnt); | |
92117d84 AS |
715 | return ERR_PTR(-EBUSY); |
716 | } | |
717 | return prog; | |
718 | } | |
59d3656d BB |
719 | EXPORT_SYMBOL_GPL(bpf_prog_add); |
720 | ||
c540594f DB |
721 | void bpf_prog_sub(struct bpf_prog *prog, int i) |
722 | { | |
723 | /* Only to be used for undoing previous bpf_prog_add() in some | |
724 | * error path. We still know that another entity in our call | |
725 | * path holds a reference to the program, thus atomic_sub() can | |
726 | * be safely used in such cases! | |
727 | */ | |
728 | WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0); | |
729 | } | |
730 | EXPORT_SYMBOL_GPL(bpf_prog_sub); | |
731 | ||
59d3656d BB |
732 | struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) |
733 | { | |
734 | return bpf_prog_add(prog, 1); | |
735 | } | |
97bc402d | 736 | EXPORT_SYMBOL_GPL(bpf_prog_inc); |
92117d84 | 737 | |
113214be | 738 | static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type) |
09756af4 AS |
739 | { |
740 | struct fd f = fdget(ufd); | |
741 | struct bpf_prog *prog; | |
742 | ||
113214be | 743 | prog = ____bpf_prog_get(f); |
09756af4 AS |
744 | if (IS_ERR(prog)) |
745 | return prog; | |
113214be DB |
746 | if (type && prog->type != *type) { |
747 | prog = ERR_PTR(-EINVAL); | |
748 | goto out; | |
749 | } | |
09756af4 | 750 | |
92117d84 | 751 | prog = bpf_prog_inc(prog); |
113214be | 752 | out: |
09756af4 AS |
753 | fdput(f); |
754 | return prog; | |
755 | } | |
113214be DB |
756 | |
757 | struct bpf_prog *bpf_prog_get(u32 ufd) | |
758 | { | |
759 | return __bpf_prog_get(ufd, NULL); | |
760 | } | |
761 | ||
762 | struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type) | |
763 | { | |
764 | return __bpf_prog_get(ufd, &type); | |
765 | } | |
766 | EXPORT_SYMBOL_GPL(bpf_prog_get_type); | |
09756af4 AS |
767 | |
768 | /* last field in 'union bpf_attr' used by this command */ | |
2541517c | 769 | #define BPF_PROG_LOAD_LAST_FIELD kern_version |
09756af4 AS |
770 | |
771 | static int bpf_prog_load(union bpf_attr *attr) | |
772 | { | |
773 | enum bpf_prog_type type = attr->prog_type; | |
774 | struct bpf_prog *prog; | |
775 | int err; | |
776 | char license[128]; | |
777 | bool is_gpl; | |
778 | ||
779 | if (CHECK_ATTR(BPF_PROG_LOAD)) | |
780 | return -EINVAL; | |
781 | ||
782 | /* copy eBPF program license from user space */ | |
535e7b4b | 783 | if (strncpy_from_user(license, u64_to_user_ptr(attr->license), |
09756af4 AS |
784 | sizeof(license) - 1) < 0) |
785 | return -EFAULT; | |
786 | license[sizeof(license) - 1] = 0; | |
787 | ||
788 | /* eBPF programs must be GPL compatible to use GPL-ed functions */ | |
789 | is_gpl = license_is_gpl_compatible(license); | |
790 | ||
ef0915ca DB |
791 | if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS) |
792 | return -E2BIG; | |
09756af4 | 793 | |
2541517c AS |
794 | if (type == BPF_PROG_TYPE_KPROBE && |
795 | attr->kern_version != LINUX_VERSION_CODE) | |
796 | return -EINVAL; | |
797 | ||
1be7f75d AS |
798 | if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN)) |
799 | return -EPERM; | |
800 | ||
09756af4 AS |
801 | /* plain bpf_prog allocation */ |
802 | prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); | |
803 | if (!prog) | |
804 | return -ENOMEM; | |
805 | ||
aaac3ba9 AS |
806 | err = bpf_prog_charge_memlock(prog); |
807 | if (err) | |
808 | goto free_prog_nouncharge; | |
809 | ||
09756af4 AS |
810 | prog->len = attr->insn_cnt; |
811 | ||
812 | err = -EFAULT; | |
535e7b4b | 813 | if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns), |
09756af4 AS |
814 | prog->len * sizeof(struct bpf_insn)) != 0) |
815 | goto free_prog; | |
816 | ||
817 | prog->orig_prog = NULL; | |
a91263d5 | 818 | prog->jited = 0; |
09756af4 AS |
819 | |
820 | atomic_set(&prog->aux->refcnt, 1); | |
a91263d5 | 821 | prog->gpl_compatible = is_gpl ? 1 : 0; |
09756af4 AS |
822 | |
823 | /* find program type: socket_filter vs tracing_filter */ | |
824 | err = find_prog_type(type, prog); | |
825 | if (err < 0) | |
826 | goto free_prog; | |
827 | ||
828 | /* run eBPF verifier */ | |
9bac3d6d | 829 | err = bpf_check(&prog, attr); |
09756af4 AS |
830 | if (err < 0) |
831 | goto free_used_maps; | |
832 | ||
0a542a86 AS |
833 | /* fixup BPF_CALL->imm field */ |
834 | fixup_bpf_calls(prog); | |
835 | ||
09756af4 | 836 | /* eBPF program is ready to be JITed */ |
d1c55ab5 | 837 | prog = bpf_prog_select_runtime(prog, &err); |
04fd61ab AS |
838 | if (err < 0) |
839 | goto free_used_maps; | |
09756af4 | 840 | |
aa79781b | 841 | err = bpf_prog_new_fd(prog); |
09756af4 AS |
842 | if (err < 0) |
843 | /* failed to allocate fd */ | |
844 | goto free_used_maps; | |
845 | ||
846 | return err; | |
847 | ||
848 | free_used_maps: | |
849 | free_used_maps(prog->aux); | |
850 | free_prog: | |
aaac3ba9 AS |
851 | bpf_prog_uncharge_memlock(prog); |
852 | free_prog_nouncharge: | |
09756af4 AS |
853 | bpf_prog_free(prog); |
854 | return err; | |
855 | } | |
856 | ||
b2197755 DB |
857 | #define BPF_OBJ_LAST_FIELD bpf_fd |
858 | ||
859 | static int bpf_obj_pin(const union bpf_attr *attr) | |
860 | { | |
861 | if (CHECK_ATTR(BPF_OBJ)) | |
862 | return -EINVAL; | |
863 | ||
535e7b4b | 864 | return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); |
b2197755 DB |
865 | } |
866 | ||
867 | static int bpf_obj_get(const union bpf_attr *attr) | |
868 | { | |
869 | if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0) | |
870 | return -EINVAL; | |
871 | ||
535e7b4b | 872 | return bpf_obj_get_user(u64_to_user_ptr(attr->pathname)); |
b2197755 DB |
873 | } |
874 | ||
f4324551 DM |
875 | #ifdef CONFIG_CGROUP_BPF |
876 | ||
877 | #define BPF_PROG_ATTACH_LAST_FIELD attach_type | |
878 | ||
879 | static int bpf_prog_attach(const union bpf_attr *attr) | |
880 | { | |
881 | struct bpf_prog *prog; | |
882 | struct cgroup *cgrp; | |
b2cd1257 | 883 | enum bpf_prog_type ptype; |
f4324551 DM |
884 | |
885 | if (!capable(CAP_NET_ADMIN)) | |
886 | return -EPERM; | |
887 | ||
888 | if (CHECK_ATTR(BPF_PROG_ATTACH)) | |
889 | return -EINVAL; | |
890 | ||
891 | switch (attr->attach_type) { | |
892 | case BPF_CGROUP_INET_INGRESS: | |
893 | case BPF_CGROUP_INET_EGRESS: | |
b2cd1257 | 894 | ptype = BPF_PROG_TYPE_CGROUP_SKB; |
f4324551 | 895 | break; |
61023658 DA |
896 | case BPF_CGROUP_INET_SOCK_CREATE: |
897 | ptype = BPF_PROG_TYPE_CGROUP_SOCK; | |
898 | break; | |
f4324551 DM |
899 | default: |
900 | return -EINVAL; | |
901 | } | |
902 | ||
b2cd1257 DA |
903 | prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); |
904 | if (IS_ERR(prog)) | |
905 | return PTR_ERR(prog); | |
906 | ||
907 | cgrp = cgroup_get_from_fd(attr->target_fd); | |
908 | if (IS_ERR(cgrp)) { | |
909 | bpf_prog_put(prog); | |
910 | return PTR_ERR(cgrp); | |
911 | } | |
912 | ||
913 | cgroup_bpf_update(cgrp, prog, attr->attach_type); | |
914 | cgroup_put(cgrp); | |
915 | ||
f4324551 DM |
916 | return 0; |
917 | } | |
918 | ||
919 | #define BPF_PROG_DETACH_LAST_FIELD attach_type | |
920 | ||
921 | static int bpf_prog_detach(const union bpf_attr *attr) | |
922 | { | |
923 | struct cgroup *cgrp; | |
924 | ||
925 | if (!capable(CAP_NET_ADMIN)) | |
926 | return -EPERM; | |
927 | ||
928 | if (CHECK_ATTR(BPF_PROG_DETACH)) | |
929 | return -EINVAL; | |
930 | ||
931 | switch (attr->attach_type) { | |
932 | case BPF_CGROUP_INET_INGRESS: | |
933 | case BPF_CGROUP_INET_EGRESS: | |
61023658 | 934 | case BPF_CGROUP_INET_SOCK_CREATE: |
f4324551 DM |
935 | cgrp = cgroup_get_from_fd(attr->target_fd); |
936 | if (IS_ERR(cgrp)) | |
937 | return PTR_ERR(cgrp); | |
938 | ||
939 | cgroup_bpf_update(cgrp, NULL, attr->attach_type); | |
940 | cgroup_put(cgrp); | |
941 | break; | |
942 | ||
943 | default: | |
944 | return -EINVAL; | |
945 | } | |
946 | ||
947 | return 0; | |
948 | } | |
949 | #endif /* CONFIG_CGROUP_BPF */ | |
950 | ||
99c55f7d AS |
951 | SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) |
952 | { | |
953 | union bpf_attr attr = {}; | |
954 | int err; | |
955 | ||
1be7f75d | 956 | if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) |
99c55f7d AS |
957 | return -EPERM; |
958 | ||
959 | if (!access_ok(VERIFY_READ, uattr, 1)) | |
960 | return -EFAULT; | |
961 | ||
962 | if (size > PAGE_SIZE) /* silly large */ | |
963 | return -E2BIG; | |
964 | ||
965 | /* If we're handed a bigger struct than we know of, | |
966 | * ensure all the unknown bits are 0 - i.e. new | |
967 | * user-space does not rely on any kernel feature | |
968 | * extensions we dont know about yet. | |
969 | */ | |
970 | if (size > sizeof(attr)) { | |
971 | unsigned char __user *addr; | |
972 | unsigned char __user *end; | |
973 | unsigned char val; | |
974 | ||
975 | addr = (void __user *)uattr + sizeof(attr); | |
976 | end = (void __user *)uattr + size; | |
977 | ||
978 | for (; addr < end; addr++) { | |
979 | err = get_user(val, addr); | |
980 | if (err) | |
981 | return err; | |
982 | if (val) | |
983 | return -E2BIG; | |
984 | } | |
985 | size = sizeof(attr); | |
986 | } | |
987 | ||
988 | /* copy attributes from user space, may be less than sizeof(bpf_attr) */ | |
989 | if (copy_from_user(&attr, uattr, size) != 0) | |
990 | return -EFAULT; | |
991 | ||
992 | switch (cmd) { | |
993 | case BPF_MAP_CREATE: | |
994 | err = map_create(&attr); | |
995 | break; | |
db20fd2b AS |
996 | case BPF_MAP_LOOKUP_ELEM: |
997 | err = map_lookup_elem(&attr); | |
998 | break; | |
999 | case BPF_MAP_UPDATE_ELEM: | |
1000 | err = map_update_elem(&attr); | |
1001 | break; | |
1002 | case BPF_MAP_DELETE_ELEM: | |
1003 | err = map_delete_elem(&attr); | |
1004 | break; | |
1005 | case BPF_MAP_GET_NEXT_KEY: | |
1006 | err = map_get_next_key(&attr); | |
1007 | break; | |
09756af4 AS |
1008 | case BPF_PROG_LOAD: |
1009 | err = bpf_prog_load(&attr); | |
1010 | break; | |
b2197755 DB |
1011 | case BPF_OBJ_PIN: |
1012 | err = bpf_obj_pin(&attr); | |
1013 | break; | |
1014 | case BPF_OBJ_GET: | |
1015 | err = bpf_obj_get(&attr); | |
1016 | break; | |
f4324551 DM |
1017 | |
1018 | #ifdef CONFIG_CGROUP_BPF | |
1019 | case BPF_PROG_ATTACH: | |
1020 | err = bpf_prog_attach(&attr); | |
1021 | break; | |
1022 | case BPF_PROG_DETACH: | |
1023 | err = bpf_prog_detach(&attr); | |
1024 | break; | |
1025 | #endif | |
1026 | ||
99c55f7d AS |
1027 | default: |
1028 | err = -EINVAL; | |
1029 | break; | |
1030 | } | |
1031 | ||
1032 | return err; | |
1033 | } |