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staging: pi433: fix spelling mistake: "preample" -> "preamble"
[linux-2.6/btrfs-unstable.git] / crypto / algif_skcipher.c
blob43839b00fe6c42fff5f8afbc04ffdff4e61a147d
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/sched/signal.h>
22 #include <linux/mm.h>
23 #include <linux/module.h>
24 #include <linux/net.h>
25 #include <net/sock.h>
26
27 struct skcipher_sg_list {
28 struct list_head list;
29
30 int cur;
31
32 struct scatterlist sg[0];
33 };
34
35 struct skcipher_tfm {
36 struct crypto_skcipher *skcipher;
37 bool has_key;
38 };
39
40 struct skcipher_ctx {
41 struct list_head tsgl;
42 struct af_alg_sgl rsgl;
43
44 void *iv;
45
46 struct af_alg_completion completion;
47
48 atomic_t inflight;
49 size_t used;
50
51 unsigned int len;
52 bool more;
53 bool merge;
54 bool enc;
55
56 struct skcipher_request req;
57 };
58
59 struct skcipher_async_rsgl {
60 struct af_alg_sgl sgl;
61 struct list_head list;
62 };
63
64 struct skcipher_async_req {
65 struct kiocb *iocb;
66 struct skcipher_async_rsgl first_sgl;
67 struct list_head list;
68 struct scatterlist *tsg;
69 atomic_t *inflight;
70 struct skcipher_request req;
71 };
72
73 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
74 sizeof(struct scatterlist) - 1)
75
76 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
77 {
78 struct skcipher_async_rsgl *rsgl, *tmp;
79 struct scatterlist *sgl;
80 struct scatterlist *sg;
81 int i, n;
82
83 list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
84 af_alg_free_sg(&rsgl->sgl);
85 if (rsgl != &sreq->first_sgl)
86 kfree(rsgl);
87 }
88 sgl = sreq->tsg;
89 n = sg_nents(sgl);
90 for_each_sg(sgl, sg, n, i)
91 put_page(sg_page(sg));
92
93 kfree(sreq->tsg);
94 }
95
96 static void skcipher_async_cb(struct crypto_async_request *req, int err)
97 {
98 struct skcipher_async_req *sreq = req->data;
99 struct kiocb *iocb = sreq->iocb;
100
101 atomic_dec(sreq->inflight);
102 skcipher_free_async_sgls(sreq);
103 kzfree(sreq);
104 iocb->ki_complete(iocb, err, err);
105 }
106
107 static inline int skcipher_sndbuf(struct sock *sk)
108 {
109 struct alg_sock *ask = alg_sk(sk);
110 struct skcipher_ctx *ctx = ask->private;
111
112 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
113 ctx->used, 0);
114 }
115
116 static inline bool skcipher_writable(struct sock *sk)
117 {
118 return PAGE_SIZE <= skcipher_sndbuf(sk);
119 }
120
121 static int skcipher_alloc_sgl(struct sock *sk)
122 {
123 struct alg_sock *ask = alg_sk(sk);
124 struct skcipher_ctx *ctx = ask->private;
125 struct skcipher_sg_list *sgl;
126 struct scatterlist *sg = NULL;
127
128 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
129 if (!list_empty(&ctx->tsgl))
130 sg = sgl->sg;
131
132 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
133 sgl = sock_kmalloc(sk, sizeof(*sgl) +
134 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
135 GFP_KERNEL);
136 if (!sgl)
137 return -ENOMEM;
138
139 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
140 sgl->cur = 0;
141
142 if (sg)
143 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
144
145 list_add_tail(&sgl->list, &ctx->tsgl);
146 }
147
148 return 0;
149 }
150
151 static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
152 {
153 struct alg_sock *ask = alg_sk(sk);
154 struct skcipher_ctx *ctx = ask->private;
155 struct skcipher_sg_list *sgl;
156 struct scatterlist *sg;
157 int i;
158
159 while (!list_empty(&ctx->tsgl)) {
160 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
161 list);
162 sg = sgl->sg;
163
164 for (i = 0; i < sgl->cur; i++) {
165 size_t plen = min_t(size_t, used, sg[i].length);
166
167 if (!sg_page(sg + i))
168 continue;
169
170 sg[i].length -= plen;
171 sg[i].offset += plen;
172
173 used -= plen;
174 ctx->used -= plen;
175
176 if (sg[i].length)
177 return;
178 if (put)
179 put_page(sg_page(sg + i));
180 sg_assign_page(sg + i, NULL);
181 }
182
183 list_del(&sgl->list);
184 sock_kfree_s(sk, sgl,
185 sizeof(*sgl) + sizeof(sgl->sg[0]) *
186 (MAX_SGL_ENTS + 1));
187 }
188
189 if (!ctx->used)
190 ctx->merge = 0;
191 }
192
193 static void skcipher_free_sgl(struct sock *sk)
194 {
195 struct alg_sock *ask = alg_sk(sk);
196 struct skcipher_ctx *ctx = ask->private;
197
198 skcipher_pull_sgl(sk, ctx->used, 1);
199 }
200
201 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
202 {
203 DEFINE_WAIT_FUNC(wait, woken_wake_function);
204 int err = -ERESTARTSYS;
205 long timeout;
206
207 if (flags & MSG_DONTWAIT)
208 return -EAGAIN;
209
210 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
211
212 add_wait_queue(sk_sleep(sk), &wait);
213 for (;;) {
214 if (signal_pending(current))
215 break;
216 timeout = MAX_SCHEDULE_TIMEOUT;
217 if (sk_wait_event(sk, &timeout, skcipher_writable(sk), &wait)) {
218 err = 0;
219 break;
220 }
221 }
222 remove_wait_queue(sk_sleep(sk), &wait);
223
224 return err;
225 }
226
227 static void skcipher_wmem_wakeup(struct sock *sk)
228 {
229 struct socket_wq *wq;
230
231 if (!skcipher_writable(sk))
232 return;
233
234 rcu_read_lock();
235 wq = rcu_dereference(sk->sk_wq);
236 if (skwq_has_sleeper(wq))
237 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
238 POLLRDNORM |
239 POLLRDBAND);
240 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
241 rcu_read_unlock();
242 }
243
244 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
245 {
246 DEFINE_WAIT_FUNC(wait, woken_wake_function);
247 struct alg_sock *ask = alg_sk(sk);
248 struct skcipher_ctx *ctx = ask->private;
249 long timeout;
250 int err = -ERESTARTSYS;
251
252 if (flags & MSG_DONTWAIT) {
253 return -EAGAIN;
254 }
255
256 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
257
258 add_wait_queue(sk_sleep(sk), &wait);
259 for (;;) {
260 if (signal_pending(current))
261 break;
262 timeout = MAX_SCHEDULE_TIMEOUT;
263 if (sk_wait_event(sk, &timeout, ctx->used, &wait)) {
264 err = 0;
265 break;
266 }
267 }
268 remove_wait_queue(sk_sleep(sk), &wait);
269
270 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
271
272 return err;
273 }
274
275 static void skcipher_data_wakeup(struct sock *sk)
276 {
277 struct alg_sock *ask = alg_sk(sk);
278 struct skcipher_ctx *ctx = ask->private;
279 struct socket_wq *wq;
280
281 if (!ctx->used)
282 return;
283
284 rcu_read_lock();
285 wq = rcu_dereference(sk->sk_wq);
286 if (skwq_has_sleeper(wq))
287 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
288 POLLRDNORM |
289 POLLRDBAND);
290 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
291 rcu_read_unlock();
292 }
293
294 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
295 size_t size)
296 {
297 struct sock *sk = sock->sk;
298 struct alg_sock *ask = alg_sk(sk);
299 struct sock *psk = ask->parent;
300 struct alg_sock *pask = alg_sk(psk);
301 struct skcipher_ctx *ctx = ask->private;
302 struct skcipher_tfm *skc = pask->private;
303 struct crypto_skcipher *tfm = skc->skcipher;
304 unsigned ivsize = crypto_skcipher_ivsize(tfm);
305 struct skcipher_sg_list *sgl;
306 struct af_alg_control con = {};
307 long copied = 0;
308 bool enc = 0;
309 bool init = 0;
310 int err;
311 int i;
312
313 if (msg->msg_controllen) {
314 err = af_alg_cmsg_send(msg, &con);
315 if (err)
316 return err;
317
318 init = 1;
319 switch (con.op) {
320 case ALG_OP_ENCRYPT:
321 enc = 1;
322 break;
323 case ALG_OP_DECRYPT:
324 enc = 0;
325 break;
326 default:
327 return -EINVAL;
328 }
329
330 if (con.iv && con.iv->ivlen != ivsize)
331 return -EINVAL;
332 }
333
334 err = -EINVAL;
335
336 lock_sock(sk);
337 if (!ctx->more && ctx->used)
338 goto unlock;
339
340 if (init) {
341 ctx->enc = enc;
342 if (con.iv)
343 memcpy(ctx->iv, con.iv->iv, ivsize);
344 }
345
346 while (size) {
347 struct scatterlist *sg;
348 unsigned long len = size;
349 size_t plen;
350
351 if (ctx->merge) {
352 sgl = list_entry(ctx->tsgl.prev,
353 struct skcipher_sg_list, list);
354 sg = sgl->sg + sgl->cur - 1;
355 len = min_t(unsigned long, len,
356 PAGE_SIZE - sg->offset - sg->length);
357
358 err = memcpy_from_msg(page_address(sg_page(sg)) +
359 sg->offset + sg->length,
360 msg, len);
361 if (err)
362 goto unlock;
363
364 sg->length += len;
365 ctx->merge = (sg->offset + sg->length) &
366 (PAGE_SIZE - 1);
367
368 ctx->used += len;
369 copied += len;
370 size -= len;
371 continue;
372 }
373
374 if (!skcipher_writable(sk)) {
375 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
376 if (err)
377 goto unlock;
378 }
379
380 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
381
382 err = skcipher_alloc_sgl(sk);
383 if (err)
384 goto unlock;
385
386 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
387 sg = sgl->sg;
388 if (sgl->cur)
389 sg_unmark_end(sg + sgl->cur - 1);
390 do {
391 i = sgl->cur;
392 plen = min_t(size_t, len, PAGE_SIZE);
393
394 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
395 err = -ENOMEM;
396 if (!sg_page(sg + i))
397 goto unlock;
398
399 err = memcpy_from_msg(page_address(sg_page(sg + i)),
400 msg, plen);
401 if (err) {
402 __free_page(sg_page(sg + i));
403 sg_assign_page(sg + i, NULL);
404 goto unlock;
405 }
406
407 sg[i].length = plen;
408 len -= plen;
409 ctx->used += plen;
410 copied += plen;
411 size -= plen;
412 sgl->cur++;
413 } while (len && sgl->cur < MAX_SGL_ENTS);
414
415 if (!size)
416 sg_mark_end(sg + sgl->cur - 1);
417
418 ctx->merge = plen & (PAGE_SIZE - 1);
419 }
420
421 err = 0;
422
423 ctx->more = msg->msg_flags & MSG_MORE;
424
425 unlock:
426 skcipher_data_wakeup(sk);
427 release_sock(sk);
428
429 return copied ?: err;
430 }
431
432 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
433 int offset, size_t size, int flags)
434 {
435 struct sock *sk = sock->sk;
436 struct alg_sock *ask = alg_sk(sk);
437 struct skcipher_ctx *ctx = ask->private;
438 struct skcipher_sg_list *sgl;
439 int err = -EINVAL;
440
441 if (flags & MSG_SENDPAGE_NOTLAST)
442 flags |= MSG_MORE;
443
444 lock_sock(sk);
445 if (!ctx->more && ctx->used)
446 goto unlock;
447
448 if (!size)
449 goto done;
450
451 if (!skcipher_writable(sk)) {
452 err = skcipher_wait_for_wmem(sk, flags);
453 if (err)
454 goto unlock;
455 }
456
457 err = skcipher_alloc_sgl(sk);
458 if (err)
459 goto unlock;
460
461 ctx->merge = 0;
462 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
463
464 if (sgl->cur)
465 sg_unmark_end(sgl->sg + sgl->cur - 1);
466
467 sg_mark_end(sgl->sg + sgl->cur);
468 get_page(page);
469 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
470 sgl->cur++;
471 ctx->used += size;
472
473 done:
474 ctx->more = flags & MSG_MORE;
475
476 unlock:
477 skcipher_data_wakeup(sk);
478 release_sock(sk);
479
480 return err ?: size;
481 }
482
483 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
484 {
485 struct skcipher_sg_list *sgl;
486 struct scatterlist *sg;
487 int nents = 0;
488
489 list_for_each_entry(sgl, &ctx->tsgl, list) {
490 sg = sgl->sg;
491
492 while (!sg->length)
493 sg++;
494
495 nents += sg_nents(sg);
496 }
497 return nents;
498 }
499
500 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
501 int flags)
502 {
503 struct sock *sk = sock->sk;
504 struct alg_sock *ask = alg_sk(sk);
505 struct sock *psk = ask->parent;
506 struct alg_sock *pask = alg_sk(psk);
507 struct skcipher_ctx *ctx = ask->private;
508 struct skcipher_tfm *skc = pask->private;
509 struct crypto_skcipher *tfm = skc->skcipher;
510 struct skcipher_sg_list *sgl;
511 struct scatterlist *sg;
512 struct skcipher_async_req *sreq;
513 struct skcipher_request *req;
514 struct skcipher_async_rsgl *last_rsgl = NULL;
515 unsigned int txbufs = 0, len = 0, tx_nents;
516 unsigned int reqsize = crypto_skcipher_reqsize(tfm);
517 unsigned int ivsize = crypto_skcipher_ivsize(tfm);
518 int err = -ENOMEM;
519 bool mark = false;
520 char *iv;
521
522 sreq = kzalloc(sizeof(*sreq) + reqsize + ivsize, GFP_KERNEL);
523 if (unlikely(!sreq))
524 goto out;
525
526 req = &sreq->req;
527 iv = (char *)(req + 1) + reqsize;
528 sreq->iocb = msg->msg_iocb;
529 INIT_LIST_HEAD(&sreq->list);
530 sreq->inflight = &ctx->inflight;
531
532 lock_sock(sk);
533 tx_nents = skcipher_all_sg_nents(ctx);
534 sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
535 if (unlikely(!sreq->tsg))
536 goto unlock;
537 sg_init_table(sreq->tsg, tx_nents);
538 memcpy(iv, ctx->iv, ivsize);
539 skcipher_request_set_tfm(req, tfm);
540 skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
541 skcipher_async_cb, sreq);
542
543 while (iov_iter_count(&msg->msg_iter)) {
544 struct skcipher_async_rsgl *rsgl;
545 int used;
546
547 if (!ctx->used) {
548 err = skcipher_wait_for_data(sk, flags);
549 if (err)
550 goto free;
551 }
552 sgl = list_first_entry(&ctx->tsgl,
553 struct skcipher_sg_list, list);
554 sg = sgl->sg;
555
556 while (!sg->length)
557 sg++;
558
559 used = min_t(unsigned long, ctx->used,
560 iov_iter_count(&msg->msg_iter));
561 used = min_t(unsigned long, used, sg->length);
562
563 if (txbufs == tx_nents) {
564 struct scatterlist *tmp;
565 int x;
566 /* Ran out of tx slots in async request
567 * need to expand */
568 tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
569 GFP_KERNEL);
570 if (!tmp) {
571 err = -ENOMEM;
572 goto free;
573 }
574
575 sg_init_table(tmp, tx_nents * 2);
576 for (x = 0; x < tx_nents; x++)
577 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
578 sreq->tsg[x].length,
579 sreq->tsg[x].offset);
580 kfree(sreq->tsg);
581 sreq->tsg = tmp;
582 tx_nents *= 2;
583 mark = true;
584 }
585 /* Need to take over the tx sgl from ctx
586 * to the asynch req - these sgls will be freed later */
587 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
588 sg->offset);
589
590 if (list_empty(&sreq->list)) {
591 rsgl = &sreq->first_sgl;
592 list_add_tail(&rsgl->list, &sreq->list);
593 } else {
594 rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
595 if (!rsgl) {
596 err = -ENOMEM;
597 goto free;
598 }
599 list_add_tail(&rsgl->list, &sreq->list);
600 }
601
602 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
603 err = used;
604 if (used < 0)
605 goto free;
606 if (last_rsgl)
607 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
608
609 last_rsgl = rsgl;
610 len += used;
611 skcipher_pull_sgl(sk, used, 0);
612 iov_iter_advance(&msg->msg_iter, used);
613 }
614
615 if (mark)
616 sg_mark_end(sreq->tsg + txbufs - 1);
617
618 skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
619 len, iv);
620 err = ctx->enc ? crypto_skcipher_encrypt(req) :
621 crypto_skcipher_decrypt(req);
622 if (err == -EINPROGRESS) {
623 atomic_inc(&ctx->inflight);
624 err = -EIOCBQUEUED;
625 sreq = NULL;
626 goto unlock;
627 }
628 free:
629 skcipher_free_async_sgls(sreq);
630 unlock:
631 skcipher_wmem_wakeup(sk);
632 release_sock(sk);
633 kzfree(sreq);
634 out:
635 return err;
636 }
637
638 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
639 int flags)
640 {
641 struct sock *sk = sock->sk;
642 struct alg_sock *ask = alg_sk(sk);
643 struct sock *psk = ask->parent;
644 struct alg_sock *pask = alg_sk(psk);
645 struct skcipher_ctx *ctx = ask->private;
646 struct skcipher_tfm *skc = pask->private;
647 struct crypto_skcipher *tfm = skc->skcipher;
648 unsigned bs = crypto_skcipher_blocksize(tfm);
649 struct skcipher_sg_list *sgl;
650 struct scatterlist *sg;
651 int err = -EAGAIN;
652 int used;
653 long copied = 0;
654
655 lock_sock(sk);
656 while (msg_data_left(msg)) {
657 if (!ctx->used) {
658 err = skcipher_wait_for_data(sk, flags);
659 if (err)
660 goto unlock;
661 }
662
663 used = min_t(unsigned long, ctx->used, msg_data_left(msg));
664
665 used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
666 err = used;
667 if (err < 0)
668 goto unlock;
669
670 if (ctx->more || used < ctx->used)
671 used -= used % bs;
672
673 err = -EINVAL;
674 if (!used)
675 goto free;
676
677 sgl = list_first_entry(&ctx->tsgl,
678 struct skcipher_sg_list, list);
679 sg = sgl->sg;
680
681 while (!sg->length)
682 sg++;
683
684 skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
685 ctx->iv);
686
687 err = af_alg_wait_for_completion(
688 ctx->enc ?
689 crypto_skcipher_encrypt(&ctx->req) :
690 crypto_skcipher_decrypt(&ctx->req),
691 &ctx->completion);
692
693 free:
694 af_alg_free_sg(&ctx->rsgl);
695
696 if (err)
697 goto unlock;
698
699 copied += used;
700 skcipher_pull_sgl(sk, used, 1);
701 iov_iter_advance(&msg->msg_iter, used);
702 }
703
704 err = 0;
705
706 unlock:
707 skcipher_wmem_wakeup(sk);
708 release_sock(sk);
709
710 return copied ?: err;
711 }
712
713 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
714 size_t ignored, int flags)
715 {
716 return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
717 skcipher_recvmsg_async(sock, msg, flags) :
718 skcipher_recvmsg_sync(sock, msg, flags);
719 }
720
721 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
722 poll_table *wait)
723 {
724 struct sock *sk = sock->sk;
725 struct alg_sock *ask = alg_sk(sk);
726 struct skcipher_ctx *ctx = ask->private;
727 unsigned int mask;
728
729 sock_poll_wait(file, sk_sleep(sk), wait);
730 mask = 0;
731
732 if (ctx->used)
733 mask |= POLLIN | POLLRDNORM;
734
735 if (skcipher_writable(sk))
736 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
737
738 return mask;
739 }
740
741 static struct proto_ops algif_skcipher_ops = {
742 .family = PF_ALG,
743
744 .connect = sock_no_connect,
745 .socketpair = sock_no_socketpair,
746 .getname = sock_no_getname,
747 .ioctl = sock_no_ioctl,
748 .listen = sock_no_listen,
749 .shutdown = sock_no_shutdown,
750 .getsockopt = sock_no_getsockopt,
751 .mmap = sock_no_mmap,
752 .bind = sock_no_bind,
753 .accept = sock_no_accept,
754 .setsockopt = sock_no_setsockopt,
755
756 .release = af_alg_release,
757 .sendmsg = skcipher_sendmsg,
758 .sendpage = skcipher_sendpage,
759 .recvmsg = skcipher_recvmsg,
760 .poll = skcipher_poll,
761 };
762
763 static int skcipher_check_key(struct socket *sock)
764 {
765 int err = 0;
766 struct sock *psk;
767 struct alg_sock *pask;
768 struct skcipher_tfm *tfm;
769 struct sock *sk = sock->sk;
770 struct alg_sock *ask = alg_sk(sk);
771
772 lock_sock(sk);
773 if (ask->refcnt)
774 goto unlock_child;
775
776 psk = ask->parent;
777 pask = alg_sk(ask->parent);
778 tfm = pask->private;
779
780 err = -ENOKEY;
781 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
782 if (!tfm->has_key)
783 goto unlock;
784
785 if (!pask->refcnt++)
786 sock_hold(psk);
787
788 ask->refcnt = 1;
789 sock_put(psk);
790
791 err = 0;
792
793 unlock:
794 release_sock(psk);
795 unlock_child:
796 release_sock(sk);
797
798 return err;
799 }
800
801 static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
802 size_t size)
803 {
804 int err;
805
806 err = skcipher_check_key(sock);
807 if (err)
808 return err;
809
810 return skcipher_sendmsg(sock, msg, size);
811 }
812
813 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
814 int offset, size_t size, int flags)
815 {
816 int err;
817
818 err = skcipher_check_key(sock);
819 if (err)
820 return err;
821
822 return skcipher_sendpage(sock, page, offset, size, flags);
823 }
824
825 static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
826 size_t ignored, int flags)
827 {
828 int err;
829
830 err = skcipher_check_key(sock);
831 if (err)
832 return err;
833
834 return skcipher_recvmsg(sock, msg, ignored, flags);
835 }
836
837 static struct proto_ops algif_skcipher_ops_nokey = {
838 .family = PF_ALG,
839
840 .connect = sock_no_connect,
841 .socketpair = sock_no_socketpair,
842 .getname = sock_no_getname,
843 .ioctl = sock_no_ioctl,
844 .listen = sock_no_listen,
845 .shutdown = sock_no_shutdown,
846 .getsockopt = sock_no_getsockopt,
847 .mmap = sock_no_mmap,
848 .bind = sock_no_bind,
849 .accept = sock_no_accept,
850 .setsockopt = sock_no_setsockopt,
851
852 .release = af_alg_release,
853 .sendmsg = skcipher_sendmsg_nokey,
854 .sendpage = skcipher_sendpage_nokey,
855 .recvmsg = skcipher_recvmsg_nokey,
856 .poll = skcipher_poll,
857 };
858
859 static void *skcipher_bind(const char *name, u32 type, u32 mask)
860 {
861 struct skcipher_tfm *tfm;
862 struct crypto_skcipher *skcipher;
863
864 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
865 if (!tfm)
866 return ERR_PTR(-ENOMEM);
867
868 skcipher = crypto_alloc_skcipher(name, type, mask);
869 if (IS_ERR(skcipher)) {
870 kfree(tfm);
871 return ERR_CAST(skcipher);
872 }
873
874 tfm->skcipher = skcipher;
875
876 return tfm;
877 }
878
879 static void skcipher_release(void *private)
880 {
881 struct skcipher_tfm *tfm = private;
882
883 crypto_free_skcipher(tfm->skcipher);
884 kfree(tfm);
885 }
886
887 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
888 {
889 struct skcipher_tfm *tfm = private;
890 int err;
891
892 err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
893 tfm->has_key = !err;
894
895 return err;
896 }
897
898 static void skcipher_wait(struct sock *sk)
899 {
900 struct alg_sock *ask = alg_sk(sk);
901 struct skcipher_ctx *ctx = ask->private;
902 int ctr = 0;
903
904 while (atomic_read(&ctx->inflight) && ctr++ < 100)
905 msleep(100);
906 }
907
908 static void skcipher_sock_destruct(struct sock *sk)
909 {
910 struct alg_sock *ask = alg_sk(sk);
911 struct skcipher_ctx *ctx = ask->private;
912 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
913
914 if (atomic_read(&ctx->inflight))
915 skcipher_wait(sk);
916
917 skcipher_free_sgl(sk);
918 sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
919 sock_kfree_s(sk, ctx, ctx->len);
920 af_alg_release_parent(sk);
921 }
922
923 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
924 {
925 struct skcipher_ctx *ctx;
926 struct alg_sock *ask = alg_sk(sk);
927 struct skcipher_tfm *tfm = private;
928 struct crypto_skcipher *skcipher = tfm->skcipher;
929 unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
930
931 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
932 if (!ctx)
933 return -ENOMEM;
934
935 ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
936 GFP_KERNEL);
937 if (!ctx->iv) {
938 sock_kfree_s(sk, ctx, len);
939 return -ENOMEM;
940 }
941
942 memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
943
944 INIT_LIST_HEAD(&ctx->tsgl);
945 ctx->len = len;
946 ctx->used = 0;
947 ctx->more = 0;
948 ctx->merge = 0;
949 ctx->enc = 0;
950 atomic_set(&ctx->inflight, 0);
951 af_alg_init_completion(&ctx->completion);
952
953 ask->private = ctx;
954
955 skcipher_request_set_tfm(&ctx->req, skcipher);
956 skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_SLEEP |
957 CRYPTO_TFM_REQ_MAY_BACKLOG,
958 af_alg_complete, &ctx->completion);
959
960 sk->sk_destruct = skcipher_sock_destruct;
961
962 return 0;
963 }
964
965 static int skcipher_accept_parent(void *private, struct sock *sk)
966 {
967 struct skcipher_tfm *tfm = private;
968
969 if (!tfm->has_key && crypto_skcipher_has_setkey(tfm->skcipher))
970 return -ENOKEY;
971
972 return skcipher_accept_parent_nokey(private, sk);
973 }
974
975 static const struct af_alg_type algif_type_skcipher = {
976 .bind = skcipher_bind,
977 .release = skcipher_release,
978 .setkey = skcipher_setkey,
979 .accept = skcipher_accept_parent,
980 .accept_nokey = skcipher_accept_parent_nokey,
981 .ops = &algif_skcipher_ops,
982 .ops_nokey = &algif_skcipher_ops_nokey,
983 .name = "skcipher",
984 .owner = THIS_MODULE
985 };
986
987 static int __init algif_skcipher_init(void)
988 {
989 return af_alg_register_type(&algif_type_skcipher);
990 }
991
992 static void __exit algif_skcipher_exit(void)
993 {
994 int err = af_alg_unregister_type(&algif_type_skcipher);
995 BUG_ON(err);
996 }
997
998 module_init(algif_skcipher_init);
999 module_exit(algif_skcipher_exit);
1000 MODULE_LICENSE("GPL");
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