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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
26struct alg_type_list {
27 const struct af_alg_type *type;
28 struct list_head list;
29};
30
31static atomic_long_t alg_memory_allocated;
32
33static 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
40static LIST_HEAD(alg_types);
41static DECLARE_RWSEM(alg_types_sem);
42
43static 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
62int 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
85unlock:
86 up_write(&alg_types_sem);
87
88 return err;
89}
90EXPORT_SYMBOL_GPL(af_alg_register_type);
91
92int 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}
111EXPORT_SYMBOL_GPL(af_alg_unregister_type);
112
113static 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
122int af_alg_release(struct socket *sock)
123{
124 if (sock->sk)
125 sock_put(sock->sk);
126 return 0;
127}
128EXPORT_SYMBOL_GPL(af_alg_release);
129
130void 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}
148EXPORT_SYMBOL_GPL(af_alg_release_parent);
149
150static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
151{
152 const u32 forbidden = CRYPTO_ALG_INTERNAL;
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 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
167 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
168
169 type = alg_get_type(sa->salg_type);
170 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
171 request_module("algif-%s", sa->salg_type);
172 type = alg_get_type(sa->salg_type);
173 }
174
175 if (IS_ERR(type))
176 return PTR_ERR(type);
177
178 private = type->bind(sa->salg_name,
179 sa->salg_feat & ~forbidden,
180 sa->salg_mask & ~forbidden);
181 if (IS_ERR(private)) {
182 module_put(type->owner);
183 return PTR_ERR(private);
184 }
185
186 err = -EBUSY;
187 lock_sock(sk);
188 if (ask->refcnt | ask->nokey_refcnt)
189 goto unlock;
190
191 swap(ask->type, type);
192 swap(ask->private, private);
193
194 err = 0;
195
196unlock:
197 release_sock(sk);
198
199 alg_do_release(type, private);
200
201 return err;
202}
203
204static int alg_setkey(struct sock *sk, char __user *ukey,
205 unsigned int keylen)
206{
207 struct alg_sock *ask = alg_sk(sk);
208 const struct af_alg_type *type = ask->type;
209 u8 *key;
210 int err;
211
212 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
213 if (!key)
214 return -ENOMEM;
215
216 err = -EFAULT;
217 if (copy_from_user(key, ukey, keylen))
218 goto out;
219
220 err = type->setkey(ask->private, key, keylen);
221
222out:
223 sock_kzfree_s(sk, key, keylen);
224
225 return err;
226}
227
228static int alg_setsockopt(struct socket *sock, int level, int optname,
229 char __user *optval, unsigned int optlen)
230{
231 struct sock *sk = sock->sk;
232 struct alg_sock *ask = alg_sk(sk);
233 const struct af_alg_type *type;
234 int err = -EBUSY;
235
236 lock_sock(sk);
237 if (ask->refcnt)
238 goto unlock;
239
240 type = ask->type;
241
242 err = -ENOPROTOOPT;
243 if (level != SOL_ALG || !type)
244 goto unlock;
245
246 switch (optname) {
247 case ALG_SET_KEY:
248 if (sock->state == SS_CONNECTED)
249 goto unlock;
250 if (!type->setkey)
251 goto unlock;
252
253 err = alg_setkey(sk, optval, optlen);
254 break;
255 case ALG_SET_AEAD_AUTHSIZE:
256 if (sock->state == SS_CONNECTED)
257 goto unlock;
258 if (!type->setauthsize)
259 goto unlock;
260 err = type->setauthsize(ask->private, optlen);
261 }
262
263unlock:
264 release_sock(sk);
265
266 return err;
267}
268
269int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
270{
271 struct alg_sock *ask = alg_sk(sk);
272 const struct af_alg_type *type;
273 struct sock *sk2;
274 unsigned int nokey;
275 int err;
276
277 lock_sock(sk);
278 type = ask->type;
279
280 err = -EINVAL;
281 if (!type)
282 goto unlock;
283
284 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
285 err = -ENOMEM;
286 if (!sk2)
287 goto unlock;
288
289 sock_init_data(newsock, sk2);
290 security_sock_graft(sk2, newsock);
291 security_sk_clone(sk, sk2);
292
293 err = type->accept(ask->private, sk2);
294
295 nokey = err == -ENOKEY;
296 if (nokey && type->accept_nokey)
297 err = type->accept_nokey(ask->private, sk2);
298
299 if (err)
300 goto unlock;
301
302 sk2->sk_family = PF_ALG;
303
304 if (nokey || !ask->refcnt++)
305 sock_hold(sk);
306 ask->nokey_refcnt += nokey;
307 alg_sk(sk2)->parent = sk;
308 alg_sk(sk2)->type = type;
309 alg_sk(sk2)->nokey_refcnt = nokey;
310
311 newsock->ops = type->ops;
312 newsock->state = SS_CONNECTED;
313
314 if (nokey)
315 newsock->ops = type->ops_nokey;
316
317 err = 0;
318
319unlock:
320 release_sock(sk);
321
322 return err;
323}
324EXPORT_SYMBOL_GPL(af_alg_accept);
325
326static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
327 bool kern)
328{
329 return af_alg_accept(sock->sk, newsock, kern);
330}
331
332static const struct proto_ops alg_proto_ops = {
333 .family = PF_ALG,
334 .owner = THIS_MODULE,
335
336 .connect = sock_no_connect,
337 .socketpair = sock_no_socketpair,
338 .getname = sock_no_getname,
339 .ioctl = sock_no_ioctl,
340 .listen = sock_no_listen,
341 .shutdown = sock_no_shutdown,
342 .getsockopt = sock_no_getsockopt,
343 .mmap = sock_no_mmap,
344 .sendpage = sock_no_sendpage,
345 .sendmsg = sock_no_sendmsg,
346 .recvmsg = sock_no_recvmsg,
347 .poll = sock_no_poll,
348
349 .bind = alg_bind,
350 .release = af_alg_release,
351 .setsockopt = alg_setsockopt,
352 .accept = alg_accept,
353};
354
355static void alg_sock_destruct(struct sock *sk)
356{
357 struct alg_sock *ask = alg_sk(sk);
358
359 alg_do_release(ask->type, ask->private);
360}
361
362static int alg_create(struct net *net, struct socket *sock, int protocol,
363 int kern)
364{
365 struct sock *sk;
366 int err;
367
368 if (sock->type != SOCK_SEQPACKET)
369 return -ESOCKTNOSUPPORT;
370 if (protocol != 0)
371 return -EPROTONOSUPPORT;
372
373 err = -ENOMEM;
374 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
375 if (!sk)
376 goto out;
377
378 sock->ops = &alg_proto_ops;
379 sock_init_data(sock, sk);
380
381 sk->sk_family = PF_ALG;
382 sk->sk_destruct = alg_sock_destruct;
383
384 return 0;
385out:
386 return err;
387}
388
389static const struct net_proto_family alg_family = {
390 .family = PF_ALG,
391 .create = alg_create,
392 .owner = THIS_MODULE,
393};
394
395int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
396{
397 size_t off;
398 ssize_t n;
399 int npages, i;
400
401 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
402 if (n < 0)
403 return n;
404
405 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
406 if (WARN_ON(npages == 0))
407 return -EINVAL;
408
409 sg_init_table(sgl->sg, npages + 1);
410
411 for (i = 0, len = n; i < npages; i++) {
412 int plen = min_t(int, len, PAGE_SIZE - off);
413
414 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
415
416 off = 0;
417 len -= plen;
418 }
419 sg_mark_end(sgl->sg + npages - 1);
420 sgl->npages = npages;
421
422 return n;
423}
424EXPORT_SYMBOL_GPL(af_alg_make_sg);
425
426void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
427{
428 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
429 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
430}
431EXPORT_SYMBOL_GPL(af_alg_link_sg);
432
433void af_alg_free_sg(struct af_alg_sgl *sgl)
434{
435 int i;
436
437 for (i = 0; i < sgl->npages; i++)
438 put_page(sgl->pages[i]);
439}
440EXPORT_SYMBOL_GPL(af_alg_free_sg);
441
442int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
443{
444 struct cmsghdr *cmsg;
445
446 for_each_cmsghdr(cmsg, msg) {
447 if (!CMSG_OK(msg, cmsg))
448 return -EINVAL;
449 if (cmsg->cmsg_level != SOL_ALG)
450 continue;
451
452 switch (cmsg->cmsg_type) {
453 case ALG_SET_IV:
454 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
455 return -EINVAL;
456 con->iv = (void *)CMSG_DATA(cmsg);
457 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
458 sizeof(*con->iv)))
459 return -EINVAL;
460 break;
461
462 case ALG_SET_OP:
463 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
464 return -EINVAL;
465 con->op = *(u32 *)CMSG_DATA(cmsg);
466 break;
467
468 case ALG_SET_AEAD_ASSOCLEN:
469 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
470 return -EINVAL;
471 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
472 break;
473
474 default:
475 return -EINVAL;
476 }
477 }
478
479 return 0;
480}
481EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
482
483int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
484{
485 switch (err) {
486 case -EINPROGRESS:
487 case -EBUSY:
488 wait_for_completion(&completion->completion);
489 reinit_completion(&completion->completion);
490 err = completion->err;
491 break;
492 };
493
494 return err;
495}
496EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
497
498void af_alg_complete(struct crypto_async_request *req, int err)
499{
500 struct af_alg_completion *completion = req->data;
501
502 if (err == -EINPROGRESS)
503 return;
504
505 completion->err = err;
506 complete(&completion->completion);
507}
508EXPORT_SYMBOL_GPL(af_alg_complete);
509
510static int __init af_alg_init(void)
511{
512 int err = proto_register(&alg_proto, 0);
513
514 if (err)
515 goto out;
516
517 err = sock_register(&alg_family);
518 if (err != 0)
519 goto out_unregister_proto;
520
521out:
522 return err;
523
524out_unregister_proto:
525 proto_unregister(&alg_proto);
526 goto out;
527}
528
529static void __exit af_alg_exit(void)
530{
531 sock_unregister(PF_ALG);
532 proto_unregister(&alg_proto);
533}
534
535module_init(af_alg_init);
536module_exit(af_alg_exit);
537MODULE_LICENSE("GPL");
538MODULE_ALIAS_NETPROTO(AF_ALG);
539
