blob: b5953f1d1a184890c4012cb994c52d576dd3dbac
1 | /* |
2 | * af_alg: User-space algorithm interface |
3 | * |
4 | * This file provides the user-space API for algorithms. |
5 | * |
6 | * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify it |
9 | * under the terms of the GNU General Public License as published by the Free |
10 | * Software Foundation; either version 2 of the License, or (at your option) |
11 | * any later version. |
12 | * |
13 | */ |
14 | |
15 | #include <linux/atomic.h> |
16 | #include <crypto/if_alg.h> |
17 | #include <linux/crypto.h> |
18 | #include <linux/init.h> |
19 | #include <linux/kernel.h> |
20 | #include <linux/list.h> |
21 | #include <linux/module.h> |
22 | #include <linux/net.h> |
23 | #include <linux/rwsem.h> |
24 | #include <linux/security.h> |
25 | |
26 | struct alg_type_list { |
27 | const struct af_alg_type *type; |
28 | struct list_head list; |
29 | }; |
30 | |
31 | static atomic_long_t alg_memory_allocated; |
32 | |
33 | static struct proto alg_proto = { |
34 | .name = "ALG", |
35 | .owner = THIS_MODULE, |
36 | .memory_allocated = &alg_memory_allocated, |
37 | .obj_size = sizeof(struct alg_sock), |
38 | }; |
39 | |
40 | static LIST_HEAD(alg_types); |
41 | static DECLARE_RWSEM(alg_types_sem); |
42 | |
43 | static const struct af_alg_type *alg_get_type(const char *name) |
44 | { |
45 | const struct af_alg_type *type = ERR_PTR(-ENOENT); |
46 | struct alg_type_list *node; |
47 | |
48 | down_read(&alg_types_sem); |
49 | list_for_each_entry(node, &alg_types, list) { |
50 | if (strcmp(node->type->name, name)) |
51 | continue; |
52 | |
53 | if (try_module_get(node->type->owner)) |
54 | type = node->type; |
55 | break; |
56 | } |
57 | up_read(&alg_types_sem); |
58 | |
59 | return type; |
60 | } |
61 | |
62 | int af_alg_register_type(const struct af_alg_type *type) |
63 | { |
64 | struct alg_type_list *node; |
65 | int err = -EEXIST; |
66 | |
67 | down_write(&alg_types_sem); |
68 | list_for_each_entry(node, &alg_types, list) { |
69 | if (!strcmp(node->type->name, type->name)) |
70 | goto unlock; |
71 | } |
72 | |
73 | node = kmalloc(sizeof(*node), GFP_KERNEL); |
74 | err = -ENOMEM; |
75 | if (!node) |
76 | goto unlock; |
77 | |
78 | type->ops->owner = THIS_MODULE; |
79 | if (type->ops_nokey) |
80 | type->ops_nokey->owner = THIS_MODULE; |
81 | node->type = type; |
82 | list_add(&node->list, &alg_types); |
83 | err = 0; |
84 | |
85 | unlock: |
86 | up_write(&alg_types_sem); |
87 | |
88 | return err; |
89 | } |
90 | EXPORT_SYMBOL_GPL(af_alg_register_type); |
91 | |
92 | int af_alg_unregister_type(const struct af_alg_type *type) |
93 | { |
94 | struct alg_type_list *node; |
95 | int err = -ENOENT; |
96 | |
97 | down_write(&alg_types_sem); |
98 | list_for_each_entry(node, &alg_types, list) { |
99 | if (strcmp(node->type->name, type->name)) |
100 | continue; |
101 | |
102 | list_del(&node->list); |
103 | kfree(node); |
104 | err = 0; |
105 | break; |
106 | } |
107 | up_write(&alg_types_sem); |
108 | |
109 | return err; |
110 | } |
111 | EXPORT_SYMBOL_GPL(af_alg_unregister_type); |
112 | |
113 | static void alg_do_release(const struct af_alg_type *type, void *private) |
114 | { |
115 | if (!type) |
116 | return; |
117 | |
118 | type->release(private); |
119 | module_put(type->owner); |
120 | } |
121 | |
122 | int af_alg_release(struct socket *sock) |
123 | { |
124 | if (sock->sk) |
125 | sock_put(sock->sk); |
126 | return 0; |
127 | } |
128 | EXPORT_SYMBOL_GPL(af_alg_release); |
129 | |
130 | void af_alg_release_parent(struct sock *sk) |
131 | { |
132 | struct alg_sock *ask = alg_sk(sk); |
133 | unsigned int nokey = ask->nokey_refcnt; |
134 | bool last = nokey && !ask->refcnt; |
135 | |
136 | sk = ask->parent; |
137 | ask = alg_sk(sk); |
138 | |
139 | lock_sock(sk); |
140 | ask->nokey_refcnt -= nokey; |
141 | if (!last) |
142 | last = !--ask->refcnt; |
143 | release_sock(sk); |
144 | |
145 | if (last) |
146 | sock_put(sk); |
147 | } |
148 | EXPORT_SYMBOL_GPL(af_alg_release_parent); |
149 | |
150 | static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
151 | { |
152 | const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; |
153 | struct sock *sk = sock->sk; |
154 | struct alg_sock *ask = alg_sk(sk); |
155 | struct sockaddr_alg *sa = (void *)uaddr; |
156 | const struct af_alg_type *type; |
157 | void *private; |
158 | int err; |
159 | |
160 | if (sock->state == SS_CONNECTED) |
161 | return -EINVAL; |
162 | |
163 | if (addr_len != sizeof(*sa)) |
164 | return -EINVAL; |
165 | |
166 | /* If caller uses non-allowed flag, return error. */ |
167 | if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) |
168 | return -EINVAL; |
169 | |
170 | sa->salg_type[sizeof(sa->salg_type) - 1] = 0; |
171 | sa->salg_name[sizeof(sa->salg_name) - 1] = 0; |
172 | |
173 | type = alg_get_type(sa->salg_type); |
174 | if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) { |
175 | request_module("algif-%s", sa->salg_type); |
176 | type = alg_get_type(sa->salg_type); |
177 | } |
178 | |
179 | if (IS_ERR(type)) |
180 | return PTR_ERR(type); |
181 | |
182 | private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); |
183 | if (IS_ERR(private)) { |
184 | module_put(type->owner); |
185 | return PTR_ERR(private); |
186 | } |
187 | |
188 | err = -EBUSY; |
189 | lock_sock(sk); |
190 | if (ask->refcnt | ask->nokey_refcnt) |
191 | goto unlock; |
192 | |
193 | swap(ask->type, type); |
194 | swap(ask->private, private); |
195 | |
196 | err = 0; |
197 | |
198 | unlock: |
199 | release_sock(sk); |
200 | |
201 | alg_do_release(type, private); |
202 | |
203 | return err; |
204 | } |
205 | |
206 | static int alg_setkey(struct sock *sk, char __user *ukey, |
207 | unsigned int keylen) |
208 | { |
209 | struct alg_sock *ask = alg_sk(sk); |
210 | const struct af_alg_type *type = ask->type; |
211 | u8 *key; |
212 | int err; |
213 | |
214 | key = sock_kmalloc(sk, keylen, GFP_KERNEL); |
215 | if (!key) |
216 | return -ENOMEM; |
217 | |
218 | err = -EFAULT; |
219 | if (copy_from_user(key, ukey, keylen)) |
220 | goto out; |
221 | |
222 | err = type->setkey(ask->private, key, keylen); |
223 | |
224 | out: |
225 | sock_kzfree_s(sk, key, keylen); |
226 | |
227 | return err; |
228 | } |
229 | |
230 | static int alg_setsockopt(struct socket *sock, int level, int optname, |
231 | char __user *optval, unsigned int optlen) |
232 | { |
233 | struct sock *sk = sock->sk; |
234 | struct alg_sock *ask = alg_sk(sk); |
235 | const struct af_alg_type *type; |
236 | int err = -EBUSY; |
237 | |
238 | lock_sock(sk); |
239 | if (ask->refcnt) |
240 | goto unlock; |
241 | |
242 | type = ask->type; |
243 | |
244 | err = -ENOPROTOOPT; |
245 | if (level != SOL_ALG || !type) |
246 | goto unlock; |
247 | |
248 | switch (optname) { |
249 | case ALG_SET_KEY: |
250 | if (sock->state == SS_CONNECTED) |
251 | goto unlock; |
252 | if (!type->setkey) |
253 | goto unlock; |
254 | |
255 | err = alg_setkey(sk, optval, optlen); |
256 | break; |
257 | case ALG_SET_AEAD_AUTHSIZE: |
258 | if (sock->state == SS_CONNECTED) |
259 | goto unlock; |
260 | if (!type->setauthsize) |
261 | goto unlock; |
262 | err = type->setauthsize(ask->private, optlen); |
263 | } |
264 | |
265 | unlock: |
266 | release_sock(sk); |
267 | |
268 | return err; |
269 | } |
270 | |
271 | int af_alg_accept(struct sock *sk, struct socket *newsock) |
272 | { |
273 | struct alg_sock *ask = alg_sk(sk); |
274 | const struct af_alg_type *type; |
275 | struct sock *sk2; |
276 | unsigned int nokey; |
277 | int err; |
278 | |
279 | lock_sock(sk); |
280 | type = ask->type; |
281 | |
282 | err = -EINVAL; |
283 | if (!type) |
284 | goto unlock; |
285 | |
286 | sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, 0); |
287 | err = -ENOMEM; |
288 | if (!sk2) |
289 | goto unlock; |
290 | |
291 | sock_init_data(newsock, sk2); |
292 | sock_graft(sk2, newsock); |
293 | security_sk_clone(sk, sk2); |
294 | |
295 | err = type->accept(ask->private, sk2); |
296 | |
297 | nokey = err == -ENOKEY; |
298 | if (nokey && type->accept_nokey) |
299 | err = type->accept_nokey(ask->private, sk2); |
300 | |
301 | if (err) |
302 | goto unlock; |
303 | |
304 | sk2->sk_family = PF_ALG; |
305 | |
306 | if (nokey || !ask->refcnt++) |
307 | sock_hold(sk); |
308 | ask->nokey_refcnt += nokey; |
309 | alg_sk(sk2)->parent = sk; |
310 | alg_sk(sk2)->type = type; |
311 | alg_sk(sk2)->nokey_refcnt = nokey; |
312 | |
313 | newsock->ops = type->ops; |
314 | newsock->state = SS_CONNECTED; |
315 | |
316 | if (nokey) |
317 | newsock->ops = type->ops_nokey; |
318 | |
319 | err = 0; |
320 | |
321 | unlock: |
322 | release_sock(sk); |
323 | |
324 | return err; |
325 | } |
326 | EXPORT_SYMBOL_GPL(af_alg_accept); |
327 | |
328 | static int alg_accept(struct socket *sock, struct socket *newsock, int flags) |
329 | { |
330 | return af_alg_accept(sock->sk, newsock); |
331 | } |
332 | |
333 | static const struct proto_ops alg_proto_ops = { |
334 | .family = PF_ALG, |
335 | .owner = THIS_MODULE, |
336 | |
337 | .connect = sock_no_connect, |
338 | .socketpair = sock_no_socketpair, |
339 | .getname = sock_no_getname, |
340 | .ioctl = sock_no_ioctl, |
341 | .listen = sock_no_listen, |
342 | .shutdown = sock_no_shutdown, |
343 | .getsockopt = sock_no_getsockopt, |
344 | .mmap = sock_no_mmap, |
345 | .sendpage = sock_no_sendpage, |
346 | .sendmsg = sock_no_sendmsg, |
347 | .recvmsg = sock_no_recvmsg, |
348 | .poll = sock_no_poll, |
349 | |
350 | .bind = alg_bind, |
351 | .release = af_alg_release, |
352 | .setsockopt = alg_setsockopt, |
353 | .accept = alg_accept, |
354 | }; |
355 | |
356 | static void alg_sock_destruct(struct sock *sk) |
357 | { |
358 | struct alg_sock *ask = alg_sk(sk); |
359 | |
360 | alg_do_release(ask->type, ask->private); |
361 | } |
362 | |
363 | static int alg_create(struct net *net, struct socket *sock, int protocol, |
364 | int kern) |
365 | { |
366 | struct sock *sk; |
367 | int err; |
368 | |
369 | if (sock->type != SOCK_SEQPACKET) |
370 | return -ESOCKTNOSUPPORT; |
371 | if (protocol != 0) |
372 | return -EPROTONOSUPPORT; |
373 | |
374 | err = -ENOMEM; |
375 | sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); |
376 | if (!sk) |
377 | goto out; |
378 | |
379 | sock->ops = &alg_proto_ops; |
380 | sock_init_data(sock, sk); |
381 | |
382 | sk->sk_family = PF_ALG; |
383 | sk->sk_destruct = alg_sock_destruct; |
384 | |
385 | return 0; |
386 | out: |
387 | return err; |
388 | } |
389 | |
390 | static const struct net_proto_family alg_family = { |
391 | .family = PF_ALG, |
392 | .create = alg_create, |
393 | .owner = THIS_MODULE, |
394 | }; |
395 | |
396 | int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len) |
397 | { |
398 | size_t off; |
399 | ssize_t n; |
400 | int npages, i; |
401 | |
402 | n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off); |
403 | if (n < 0) |
404 | return n; |
405 | |
406 | npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT; |
407 | if (WARN_ON(npages == 0)) |
408 | return -EINVAL; |
409 | /* Add one extra for linking */ |
410 | sg_init_table(sgl->sg, npages + 1); |
411 | |
412 | for (i = 0, len = n; i < npages; i++) { |
413 | int plen = min_t(int, len, PAGE_SIZE - off); |
414 | |
415 | sg_set_page(sgl->sg + i, sgl->pages[i], plen, off); |
416 | |
417 | off = 0; |
418 | len -= plen; |
419 | } |
420 | sg_mark_end(sgl->sg + npages - 1); |
421 | sgl->npages = npages; |
422 | |
423 | return n; |
424 | } |
425 | EXPORT_SYMBOL_GPL(af_alg_make_sg); |
426 | |
427 | void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new) |
428 | { |
429 | sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1); |
430 | sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg); |
431 | } |
432 | EXPORT_SYMBOL_GPL(af_alg_link_sg); |
433 | |
434 | void af_alg_free_sg(struct af_alg_sgl *sgl) |
435 | { |
436 | int i; |
437 | |
438 | for (i = 0; i < sgl->npages; i++) |
439 | put_page(sgl->pages[i]); |
440 | } |
441 | EXPORT_SYMBOL_GPL(af_alg_free_sg); |
442 | |
443 | int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) |
444 | { |
445 | struct cmsghdr *cmsg; |
446 | |
447 | for_each_cmsghdr(cmsg, msg) { |
448 | if (!CMSG_OK(msg, cmsg)) |
449 | return -EINVAL; |
450 | if (cmsg->cmsg_level != SOL_ALG) |
451 | continue; |
452 | |
453 | switch (cmsg->cmsg_type) { |
454 | case ALG_SET_IV: |
455 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) |
456 | return -EINVAL; |
457 | con->iv = (void *)CMSG_DATA(cmsg); |
458 | if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + |
459 | sizeof(*con->iv))) |
460 | return -EINVAL; |
461 | break; |
462 | |
463 | case ALG_SET_OP: |
464 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) |
465 | return -EINVAL; |
466 | con->op = *(u32 *)CMSG_DATA(cmsg); |
467 | break; |
468 | |
469 | case ALG_SET_AEAD_ASSOCLEN: |
470 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) |
471 | return -EINVAL; |
472 | con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); |
473 | break; |
474 | |
475 | default: |
476 | return -EINVAL; |
477 | } |
478 | } |
479 | |
480 | return 0; |
481 | } |
482 | EXPORT_SYMBOL_GPL(af_alg_cmsg_send); |
483 | |
484 | int af_alg_wait_for_completion(int err, struct af_alg_completion *completion) |
485 | { |
486 | switch (err) { |
487 | case -EINPROGRESS: |
488 | case -EBUSY: |
489 | wait_for_completion(&completion->completion); |
490 | reinit_completion(&completion->completion); |
491 | err = completion->err; |
492 | break; |
493 | }; |
494 | |
495 | return err; |
496 | } |
497 | EXPORT_SYMBOL_GPL(af_alg_wait_for_completion); |
498 | |
499 | void af_alg_complete(struct crypto_async_request *req, int err) |
500 | { |
501 | struct af_alg_completion *completion = req->data; |
502 | |
503 | if (err == -EINPROGRESS) |
504 | return; |
505 | |
506 | completion->err = err; |
507 | complete(&completion->completion); |
508 | } |
509 | EXPORT_SYMBOL_GPL(af_alg_complete); |
510 | |
511 | static int __init af_alg_init(void) |
512 | { |
513 | int err = proto_register(&alg_proto, 0); |
514 | |
515 | if (err) |
516 | goto out; |
517 | |
518 | err = sock_register(&alg_family); |
519 | if (err != 0) |
520 | goto out_unregister_proto; |
521 | |
522 | out: |
523 | return err; |
524 | |
525 | out_unregister_proto: |
526 | proto_unregister(&alg_proto); |
527 | goto out; |
528 | } |
529 | |
530 | static void __exit af_alg_exit(void) |
531 | { |
532 | sock_unregister(PF_ALG); |
533 | proto_unregister(&alg_proto); |
534 | } |
535 | |
536 | module_init(af_alg_init); |
537 | module_exit(af_alg_exit); |
538 | MODULE_LICENSE("GPL"); |
539 | MODULE_ALIAS_NETPROTO(AF_ALG); |
540 |