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1 /*
2 * algif_skcipher: User-space interface for skcipher algorithms
3 *
4 * This file provides the user-space API for symmetric key ciphers.
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 <crypto/scatterwalk.h>
16 #include <crypto/skcipher.h>
17 #include <crypto/if_alg.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/module.h>
23 #include <linux/net.h>
24 #include <net/sock.h>
25
26 struct skcipher_sg_list {
27 struct list_head list;
28
29 int cur;
30
31 struct scatterlist sg[0];
32 };
33
34 struct skcipher_ctx {
35 struct list_head tsgl;
36 struct af_alg_sgl rsgl;
37
38 void *iv;
39
40 struct af_alg_completion completion;
41
42 atomic_t inflight;
43 size_t used;
44
45 unsigned int len;
46 bool more;
47 bool merge;
48 bool enc;
49
50 struct skcipher_request req;
51 };
52
53 struct skcipher_async_rsgl {
54 struct af_alg_sgl sgl;
55 struct list_head list;
56 };
57
58 struct skcipher_async_req {
59 struct kiocb *iocb;
60 struct skcipher_async_rsgl first_sgl;
61 struct list_head list;
62 struct scatterlist *tsg;
63 char iv[];
64 };
65
66 #define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
67 crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req)))
68
69 #define GET_REQ_SIZE(ctx) \
70 crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req))
71
72 #define GET_IV_SIZE(ctx) \
73 crypto_skcipher_ivsize(crypto_skcipher_reqtfm(&ctx->req))
74
75 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
76 sizeof(struct scatterlist) - 1)
77
78 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
79 {
80 struct skcipher_async_rsgl *rsgl, *tmp;
81 struct scatterlist *sgl;
82 struct scatterlist *sg;
83 int i, n;
84
85 list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
86 af_alg_free_sg(&rsgl->sgl);
87 if (rsgl != &sreq->first_sgl)
88 kfree(rsgl);
89 }
90 sgl = sreq->tsg;
91 n = sg_nents(sgl);
92 for_each_sg(sgl, sg, n, i)
93 put_page(sg_page(sg));
94
95 kfree(sreq->tsg);
96 }
97
98 static void skcipher_async_cb(struct crypto_async_request *req, int err)
99 {
100 struct sock *sk = req->data;
101 struct alg_sock *ask = alg_sk(sk);
102 struct skcipher_ctx *ctx = ask->private;
103 struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
104 struct kiocb *iocb = sreq->iocb;
105
106 atomic_dec(&ctx->inflight);
107 skcipher_free_async_sgls(sreq);
108 kfree(req);
109 iocb->ki_complete(iocb, err, err);
110 }
111
112 static inline int skcipher_sndbuf(struct sock *sk)
113 {
114 struct alg_sock *ask = alg_sk(sk);
115 struct skcipher_ctx *ctx = ask->private;
116
117 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
118 ctx->used, 0);
119 }
120
121 static inline bool skcipher_writable(struct sock *sk)
122 {
123 return PAGE_SIZE <= skcipher_sndbuf(sk);
124 }
125
126 static int skcipher_alloc_sgl(struct sock *sk)
127 {
128 struct alg_sock *ask = alg_sk(sk);
129 struct skcipher_ctx *ctx = ask->private;
130 struct skcipher_sg_list *sgl;
131 struct scatterlist *sg = NULL;
132
133 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
134 if (!list_empty(&ctx->tsgl))
135 sg = sgl->sg;
136
137 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
138 sgl = sock_kmalloc(sk, sizeof(*sgl) +
139 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
140 GFP_KERNEL);
141 if (!sgl)
142 return -ENOMEM;
143
144 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
145 sgl->cur = 0;
146
147 if (sg)
148 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
149
150 list_add_tail(&sgl->list, &ctx->tsgl);
151 }
152
153 return 0;
154 }
155
156 static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
157 {
158 struct alg_sock *ask = alg_sk(sk);
159 struct skcipher_ctx *ctx = ask->private;
160 struct skcipher_sg_list *sgl;
161 struct scatterlist *sg;
162 int i;
163
164 while (!list_empty(&ctx->tsgl)) {
165 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
166 list);
167 sg = sgl->sg;
168
169 for (i = 0; i < sgl->cur; i++) {
170 size_t plen = min_t(size_t, used, sg[i].length);
171
172 if (!sg_page(sg + i))
173 continue;
174
175 sg[i].length -= plen;
176 sg[i].offset += plen;
177
178 used -= plen;
179 ctx->used -= plen;
180
181 if (sg[i].length)
182 return;
183 if (put)
184 put_page(sg_page(sg + i));
185 sg_assign_page(sg + i, NULL);
186 }
187
188 list_del(&sgl->list);
189 sock_kfree_s(sk, sgl,
190 sizeof(*sgl) + sizeof(sgl->sg[0]) *
191 (MAX_SGL_ENTS + 1));
192 }
193
194 if (!ctx->used)
195 ctx->merge = 0;
196 }
197
198 static void skcipher_free_sgl(struct sock *sk)
199 {
200 struct alg_sock *ask = alg_sk(sk);
201 struct skcipher_ctx *ctx = ask->private;
202
203 skcipher_pull_sgl(sk, ctx->used, 1);
204 }
205
206 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
207 {
208 long timeout;
209 DEFINE_WAIT(wait);
210 int err = -ERESTARTSYS;
211
212 if (flags & MSG_DONTWAIT)
213 return -EAGAIN;
214
215 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
216
217 for (;;) {
218 if (signal_pending(current))
219 break;
220 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
221 timeout = MAX_SCHEDULE_TIMEOUT;
222 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
223 err = 0;
224 break;
225 }
226 }
227 finish_wait(sk_sleep(sk), &wait);
228
229 return err;
230 }
231
232 static void skcipher_wmem_wakeup(struct sock *sk)
233 {
234 struct socket_wq *wq;
235
236 if (!skcipher_writable(sk))
237 return;
238
239 rcu_read_lock();
240 wq = rcu_dereference(sk->sk_wq);
241 if (skwq_has_sleeper(wq))
242 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
243 POLLRDNORM |
244 POLLRDBAND);
245 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
246 rcu_read_unlock();
247 }
248
249 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
250 {
251 struct alg_sock *ask = alg_sk(sk);
252 struct skcipher_ctx *ctx = ask->private;
253 long timeout;
254 DEFINE_WAIT(wait);
255 int err = -ERESTARTSYS;
256
257 if (flags & MSG_DONTWAIT) {
258 return -EAGAIN;
259 }
260
261 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
262
263 for (;;) {
264 if (signal_pending(current))
265 break;
266 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
267 timeout = MAX_SCHEDULE_TIMEOUT;
268 if (sk_wait_event(sk, &timeout, ctx->used)) {
269 err = 0;
270 break;
271 }
272 }
273 finish_wait(sk_sleep(sk), &wait);
274
275 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
276
277 return err;
278 }
279
280 static void skcipher_data_wakeup(struct sock *sk)
281 {
282 struct alg_sock *ask = alg_sk(sk);
283 struct skcipher_ctx *ctx = ask->private;
284 struct socket_wq *wq;
285
286 if (!ctx->used)
287 return;
288
289 rcu_read_lock();
290 wq = rcu_dereference(sk->sk_wq);
291 if (skwq_has_sleeper(wq))
292 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
293 POLLRDNORM |
294 POLLRDBAND);
295 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
296 rcu_read_unlock();
297 }
298
299 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
300 size_t size)
301 {
302 struct sock *sk = sock->sk;
303 struct alg_sock *ask = alg_sk(sk);
304 struct skcipher_ctx *ctx = ask->private;
305 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
306 unsigned ivsize = crypto_skcipher_ivsize(tfm);
307 struct skcipher_sg_list *sgl;
308 struct af_alg_control con = {};
309 long copied = 0;
310 bool enc = 0;
311 bool init = 0;
312 int err;
313 int i;
314
315 if (msg->msg_controllen) {
316 err = af_alg_cmsg_send(msg, &con);
317 if (err)
318 return err;
319
320 init = 1;
321 switch (con.op) {
322 case ALG_OP_ENCRYPT:
323 enc = 1;
324 break;
325 case ALG_OP_DECRYPT:
326 enc = 0;
327 break;
328 default:
329 return -EINVAL;
330 }
331
332 if (con.iv && con.iv->ivlen != ivsize)
333 return -EINVAL;
334 }
335
336 err = -EINVAL;
337
338 lock_sock(sk);
339 if (!ctx->more && ctx->used)
340 goto unlock;
341
342 if (init) {
343 ctx->enc = enc;
344 if (con.iv)
345 memcpy(ctx->iv, con.iv->iv, ivsize);
346 }
347
348 while (size) {
349 struct scatterlist *sg;
350 unsigned long len = size;
351 size_t plen;
352
353 if (ctx->merge) {
354 sgl = list_entry(ctx->tsgl.prev,
355 struct skcipher_sg_list, list);
356 sg = sgl->sg + sgl->cur - 1;
357 len = min_t(unsigned long, len,
358 PAGE_SIZE - sg->offset - sg->length);
359
360 err = memcpy_from_msg(page_address(sg_page(sg)) +
361 sg->offset + sg->length,
362 msg, len);
363 if (err)
364 goto unlock;
365
366 sg->length += len;
367 ctx->merge = (sg->offset + sg->length) &
368 (PAGE_SIZE - 1);
369
370 ctx->used += len;
371 copied += len;
372 size -= len;
373 continue;
374 }
375
376 if (!skcipher_writable(sk)) {
377 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
378 if (err)
379 goto unlock;
380 }
381
382 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
383
384 err = skcipher_alloc_sgl(sk);
385 if (err)
386 goto unlock;
387
388 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
389 sg = sgl->sg;
390 sg_unmark_end(sg + sgl->cur);
391 do {
392 i = sgl->cur;
393 plen = min_t(size_t, len, PAGE_SIZE);
394
395 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
396 err = -ENOMEM;
397 if (!sg_page(sg + i))
398 goto unlock;
399
400 err = memcpy_from_msg(page_address(sg_page(sg + i)),
401 msg, plen);
402 if (err) {
403 __free_page(sg_page(sg + i));
404 sg_assign_page(sg + i, NULL);
405 goto unlock;
406 }
407
408 sg[i].length = plen;
409 len -= plen;
410 ctx->used += plen;
411 copied += plen;
412 size -= plen;
413 sgl->cur++;
414 } while (len && sgl->cur < MAX_SGL_ENTS);
415
416 if (!size)
417 sg_mark_end(sg + sgl->cur - 1);
418
419 ctx->merge = plen & (PAGE_SIZE - 1);
420 }
421
422 err = 0;
423
424 ctx->more = msg->msg_flags & MSG_MORE;
425
426 unlock:
427 skcipher_data_wakeup(sk);
428 release_sock(sk);
429
430 return copied ?: err;
431 }
432
433 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
434 int offset, size_t size, int flags)
435 {
436 struct sock *sk = sock->sk;
437 struct alg_sock *ask = alg_sk(sk);
438 struct skcipher_ctx *ctx = ask->private;
439 struct skcipher_sg_list *sgl;
440 int err = -EINVAL;
441
442 if (flags & MSG_SENDPAGE_NOTLAST)
443 flags |= MSG_MORE;
444
445 lock_sock(sk);
446 if (!ctx->more && ctx->used)
447 goto unlock;
448
449 if (!size)
450 goto done;
451
452 if (!skcipher_writable(sk)) {
453 err = skcipher_wait_for_wmem(sk, flags);
454 if (err)
455 goto unlock;
456 }
457
458 err = skcipher_alloc_sgl(sk);
459 if (err)
460 goto unlock;
461
462 ctx->merge = 0;
463 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
464
465 if (sgl->cur)
466 sg_unmark_end(sgl->sg + sgl->cur - 1);
467
468 sg_mark_end(sgl->sg + sgl->cur);
469 get_page(page);
470 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
471 sgl->cur++;
472 ctx->used += size;
473
474 done:
475 ctx->more = flags & MSG_MORE;
476
477 unlock:
478 skcipher_data_wakeup(sk);
479 release_sock(sk);
480
481 return err ?: size;
482 }
483
484 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
485 {
486 struct skcipher_sg_list *sgl;
487 struct scatterlist *sg;
488 int nents = 0;
489
490 list_for_each_entry(sgl, &ctx->tsgl, list) {
491 sg = sgl->sg;
492
493 while (!sg->length)
494 sg++;
495
496 nents += sg_nents(sg);
497 }
498 return nents;
499 }
500
501 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
502 int flags)
503 {
504 struct sock *sk = sock->sk;
505 struct alg_sock *ask = alg_sk(sk);
506 struct skcipher_ctx *ctx = ask->private;
507 struct skcipher_sg_list *sgl;
508 struct scatterlist *sg;
509 struct skcipher_async_req *sreq;
510 struct skcipher_request *req;
511 struct skcipher_async_rsgl *last_rsgl = NULL;
512 unsigned int txbufs = 0, len = 0, tx_nents = skcipher_all_sg_nents(ctx);
513 unsigned int reqlen = sizeof(struct skcipher_async_req) +
514 GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
515 int err = -ENOMEM;
516 bool mark = false;
517
518 lock_sock(sk);
519 req = kmalloc(reqlen, GFP_KERNEL);
520 if (unlikely(!req))
521 goto unlock;
522
523 sreq = GET_SREQ(req, ctx);
524 sreq->iocb = msg->msg_iocb;
525 memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl));
526 INIT_LIST_HEAD(&sreq->list);
527 sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
528 if (unlikely(!sreq->tsg)) {
529 kfree(req);
530 goto unlock;
531 }
532 sg_init_table(sreq->tsg, tx_nents);
533 memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
534 skcipher_request_set_tfm(req, crypto_skcipher_reqtfm(&ctx->req));
535 skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
536 skcipher_async_cb, sk);
537
538 while (iov_iter_count(&msg->msg_iter)) {
539 struct skcipher_async_rsgl *rsgl;
540 int used;
541
542 if (!ctx->used) {
543 err = skcipher_wait_for_data(sk, flags);
544 if (err)
545 goto free;
546 }
547 sgl = list_first_entry(&ctx->tsgl,
548 struct skcipher_sg_list, list);
549 sg = sgl->sg;
550
551 while (!sg->length)
552 sg++;
553
554 used = min_t(unsigned long, ctx->used,
555 iov_iter_count(&msg->msg_iter));
556 used = min_t(unsigned long, used, sg->length);
557
558 if (txbufs == tx_nents) {
559 struct scatterlist *tmp;
560 int x;
561 /* Ran out of tx slots in async request
562 * need to expand */
563 tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
564 GFP_KERNEL);
565 if (!tmp)
566 goto free;
567
568 sg_init_table(tmp, tx_nents * 2);
569 for (x = 0; x < tx_nents; x++)
570 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
571 sreq->tsg[x].length,
572 sreq->tsg[x].offset);
573 kfree(sreq->tsg);
574 sreq->tsg = tmp;
575 tx_nents *= 2;
576 mark = true;
577 }
578 /* Need to take over the tx sgl from ctx
579 * to the asynch req - these sgls will be freed later */
580 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
581 sg->offset);
582
583 if (list_empty(&sreq->list)) {
584 rsgl = &sreq->first_sgl;
585 list_add_tail(&rsgl->list, &sreq->list);
586 } else {
587 rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
588 if (!rsgl) {
589 err = -ENOMEM;
590 goto free;
591 }
592 list_add_tail(&rsgl->list, &sreq->list);
593 }
594
595 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
596 err = used;
597 if (used < 0)
598 goto free;
599 if (last_rsgl)
600 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
601
602 last_rsgl = rsgl;
603 len += used;
604 skcipher_pull_sgl(sk, used, 0);
605 iov_iter_advance(&msg->msg_iter, used);
606 }
607
608 if (mark)
609 sg_mark_end(sreq->tsg + txbufs - 1);
610
611 skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
612 len, sreq->iv);
613 err = ctx->enc ? crypto_skcipher_encrypt(req) :
614 crypto_skcipher_decrypt(req);
615 if (err == -EINPROGRESS) {
616 atomic_inc(&ctx->inflight);
617 err = -EIOCBQUEUED;
618 goto unlock;
619 }
620 free:
621 skcipher_free_async_sgls(sreq);
622 kfree(req);
623 unlock:
624 skcipher_wmem_wakeup(sk);
625 release_sock(sk);
626 return err;
627 }
628
629 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
630 int flags)
631 {
632 struct sock *sk = sock->sk;
633 struct alg_sock *ask = alg_sk(sk);
634 struct skcipher_ctx *ctx = ask->private;
635 unsigned bs = crypto_skcipher_blocksize(crypto_skcipher_reqtfm(
636 &ctx->req));
637 struct skcipher_sg_list *sgl;
638 struct scatterlist *sg;
639 int err = -EAGAIN;
640 int used;
641 long copied = 0;
642
643 lock_sock(sk);
644 while (msg_data_left(msg)) {
645 sgl = list_first_entry(&ctx->tsgl,
646 struct skcipher_sg_list, list);
647 sg = sgl->sg;
648
649 while (!sg->length)
650 sg++;
651
652 if (!ctx->used) {
653 err = skcipher_wait_for_data(sk, flags);
654 if (err)
655 goto unlock;
656 }
657
658 used = min_t(unsigned long, ctx->used, msg_data_left(msg));
659
660 used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
661 err = used;
662 if (err < 0)
663 goto unlock;
664
665 if (ctx->more || used < ctx->used)
666 used -= used % bs;
667
668 err = -EINVAL;
669 if (!used)
670 goto free;
671
672 skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
673 ctx->iv);
674
675 err = af_alg_wait_for_completion(
676 ctx->enc ?
677 crypto_skcipher_encrypt(&ctx->req) :
678 crypto_skcipher_decrypt(&ctx->req),
679 &ctx->completion);
680
681 free:
682 af_alg_free_sg(&ctx->rsgl);
683
684 if (err)
685 goto unlock;
686
687 copied += used;
688 skcipher_pull_sgl(sk, used, 1);
689 iov_iter_advance(&msg->msg_iter, used);
690 }
691
692 err = 0;
693
694 unlock:
695 skcipher_wmem_wakeup(sk);
696 release_sock(sk);
697
698 return copied ?: err;
699 }
700
701 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
702 size_t ignored, int flags)
703 {
704 return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
705 skcipher_recvmsg_async(sock, msg, flags) :
706 skcipher_recvmsg_sync(sock, msg, flags);
707 }
708
709 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
710 poll_table *wait)
711 {
712 struct sock *sk = sock->sk;
713 struct alg_sock *ask = alg_sk(sk);
714 struct skcipher_ctx *ctx = ask->private;
715 unsigned int mask;
716
717 sock_poll_wait(file, sk_sleep(sk), wait);
718 mask = 0;
719
720 if (ctx->used)
721 mask |= POLLIN | POLLRDNORM;
722
723 if (skcipher_writable(sk))
724 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
725
726 return mask;
727 }
728
729 static struct proto_ops algif_skcipher_ops = {
730 .family = PF_ALG,
731
732 .connect = sock_no_connect,
733 .socketpair = sock_no_socketpair,
734 .getname = sock_no_getname,
735 .ioctl = sock_no_ioctl,
736 .listen = sock_no_listen,
737 .shutdown = sock_no_shutdown,
738 .getsockopt = sock_no_getsockopt,
739 .mmap = sock_no_mmap,
740 .bind = sock_no_bind,
741 .accept = sock_no_accept,
742 .setsockopt = sock_no_setsockopt,
743
744 .release = af_alg_release,
745 .sendmsg = skcipher_sendmsg,
746 .sendpage = skcipher_sendpage,
747 .recvmsg = skcipher_recvmsg,
748 .poll = skcipher_poll,
749 };
750
751 static void *skcipher_bind(const char *name, u32 type, u32 mask)
752 {
753 return crypto_alloc_skcipher(name, type, mask);
754 }
755
756 static void skcipher_release(void *private)
757 {
758 crypto_free_skcipher(private);
759 }
760
761 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
762 {
763 return crypto_skcipher_setkey(private, key, keylen);
764 }
765
766 static void skcipher_wait(struct sock *sk)
767 {
768 struct alg_sock *ask = alg_sk(sk);
769 struct skcipher_ctx *ctx = ask->private;
770 int ctr = 0;
771
772 while (atomic_read(&ctx->inflight) && ctr++ < 100)
773 msleep(100);
774 }
775
776 static void skcipher_sock_destruct(struct sock *sk)
777 {
778 struct alg_sock *ask = alg_sk(sk);
779 struct skcipher_ctx *ctx = ask->private;
780 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
781
782 if (atomic_read(&ctx->inflight))
783 skcipher_wait(sk);
784
785 skcipher_free_sgl(sk);
786 sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
787 sock_kfree_s(sk, ctx, ctx->len);
788 af_alg_release_parent(sk);
789 }
790
791 static int skcipher_accept_parent(void *private, struct sock *sk)
792 {
793 struct skcipher_ctx *ctx;
794 struct alg_sock *ask = alg_sk(sk);
795 unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(private);
796
797 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
798 if (!ctx)
799 return -ENOMEM;
800
801 ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(private),
802 GFP_KERNEL);
803 if (!ctx->iv) {
804 sock_kfree_s(sk, ctx, len);
805 return -ENOMEM;
806 }
807
808 memset(ctx->iv, 0, crypto_skcipher_ivsize(private));
809
810 INIT_LIST_HEAD(&ctx->tsgl);
811 ctx->len = len;
812 ctx->used = 0;
813 ctx->more = 0;
814 ctx->merge = 0;
815 ctx->enc = 0;
816 atomic_set(&ctx->inflight, 0);
817 af_alg_init_completion(&ctx->completion);
818
819 ask->private = ctx;
820
821 skcipher_request_set_tfm(&ctx->req, private);
822 skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
823 af_alg_complete, &ctx->completion);
824
825 sk->sk_destruct = skcipher_sock_destruct;
826
827 return 0;
828 }
829
830 static const struct af_alg_type algif_type_skcipher = {
831 .bind = skcipher_bind,
832 .release = skcipher_release,
833 .setkey = skcipher_setkey,
834 .accept = skcipher_accept_parent,
835 .ops = &algif_skcipher_ops,
836 .name = "skcipher",
837 .owner = THIS_MODULE
838 };
839
840 static int __init algif_skcipher_init(void)
841 {
842 return af_alg_register_type(&algif_type_skcipher);
843 }
844
845 static void __exit algif_skcipher_exit(void)
846 {
847 int err = af_alg_unregister_type(&algif_type_skcipher);
848 BUG_ON(err);
849 }
850
851 module_init(algif_skcipher_init);
852 module_exit(algif_skcipher_exit);
853 MODULE_LICENSE("GPL");