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crypto: algif_skcipher - Add nokey compatibility path
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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_tfm {
35 struct crypto_skcipher *skcipher;
36 bool has_key;
37 };
38
39 struct skcipher_ctx {
40 struct list_head tsgl;
41 struct af_alg_sgl rsgl;
42
43 void *iv;
44
45 struct af_alg_completion completion;
46
47 atomic_t inflight;
48 size_t used;
49
50 unsigned int len;
51 bool more;
52 bool merge;
53 bool enc;
54
55 struct skcipher_request req;
56 };
57
58 struct skcipher_async_rsgl {
59 struct af_alg_sgl sgl;
60 struct list_head list;
61 };
62
63 struct skcipher_async_req {
64 struct kiocb *iocb;
65 struct skcipher_async_rsgl first_sgl;
66 struct list_head list;
67 struct scatterlist *tsg;
68 char iv[];
69 };
70
71 #define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
72 crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req)))
73
74 #define GET_REQ_SIZE(ctx) \
75 crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req))
76
77 #define GET_IV_SIZE(ctx) \
78 crypto_skcipher_ivsize(crypto_skcipher_reqtfm(&ctx->req))
79
80 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
81 sizeof(struct scatterlist) - 1)
82
83 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
84 {
85 struct skcipher_async_rsgl *rsgl, *tmp;
86 struct scatterlist *sgl;
87 struct scatterlist *sg;
88 int i, n;
89
90 list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
91 af_alg_free_sg(&rsgl->sgl);
92 if (rsgl != &sreq->first_sgl)
93 kfree(rsgl);
94 }
95 sgl = sreq->tsg;
96 n = sg_nents(sgl);
97 for_each_sg(sgl, sg, n, i)
98 put_page(sg_page(sg));
99
100 kfree(sreq->tsg);
101 }
102
103 static void skcipher_async_cb(struct crypto_async_request *req, int err)
104 {
105 struct sock *sk = req->data;
106 struct alg_sock *ask = alg_sk(sk);
107 struct skcipher_ctx *ctx = ask->private;
108 struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
109 struct kiocb *iocb = sreq->iocb;
110
111 atomic_dec(&ctx->inflight);
112 skcipher_free_async_sgls(sreq);
113 kfree(req);
114 iocb->ki_complete(iocb, err, err);
115 }
116
117 static inline int skcipher_sndbuf(struct sock *sk)
118 {
119 struct alg_sock *ask = alg_sk(sk);
120 struct skcipher_ctx *ctx = ask->private;
121
122 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
123 ctx->used, 0);
124 }
125
126 static inline bool skcipher_writable(struct sock *sk)
127 {
128 return PAGE_SIZE <= skcipher_sndbuf(sk);
129 }
130
131 static int skcipher_alloc_sgl(struct sock *sk)
132 {
133 struct alg_sock *ask = alg_sk(sk);
134 struct skcipher_ctx *ctx = ask->private;
135 struct skcipher_sg_list *sgl;
136 struct scatterlist *sg = NULL;
137
138 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
139 if (!list_empty(&ctx->tsgl))
140 sg = sgl->sg;
141
142 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
143 sgl = sock_kmalloc(sk, sizeof(*sgl) +
144 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
145 GFP_KERNEL);
146 if (!sgl)
147 return -ENOMEM;
148
149 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
150 sgl->cur = 0;
151
152 if (sg)
153 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
154
155 list_add_tail(&sgl->list, &ctx->tsgl);
156 }
157
158 return 0;
159 }
160
161 static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
162 {
163 struct alg_sock *ask = alg_sk(sk);
164 struct skcipher_ctx *ctx = ask->private;
165 struct skcipher_sg_list *sgl;
166 struct scatterlist *sg;
167 int i;
168
169 while (!list_empty(&ctx->tsgl)) {
170 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
171 list);
172 sg = sgl->sg;
173
174 for (i = 0; i < sgl->cur; i++) {
175 size_t plen = min_t(size_t, used, sg[i].length);
176
177 if (!sg_page(sg + i))
178 continue;
179
180 sg[i].length -= plen;
181 sg[i].offset += plen;
182
183 used -= plen;
184 ctx->used -= plen;
185
186 if (sg[i].length)
187 return;
188 if (put)
189 put_page(sg_page(sg + i));
190 sg_assign_page(sg + i, NULL);
191 }
192
193 list_del(&sgl->list);
194 sock_kfree_s(sk, sgl,
195 sizeof(*sgl) + sizeof(sgl->sg[0]) *
196 (MAX_SGL_ENTS + 1));
197 }
198
199 if (!ctx->used)
200 ctx->merge = 0;
201 }
202
203 static void skcipher_free_sgl(struct sock *sk)
204 {
205 struct alg_sock *ask = alg_sk(sk);
206 struct skcipher_ctx *ctx = ask->private;
207
208 skcipher_pull_sgl(sk, ctx->used, 1);
209 }
210
211 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
212 {
213 long timeout;
214 DEFINE_WAIT(wait);
215 int err = -ERESTARTSYS;
216
217 if (flags & MSG_DONTWAIT)
218 return -EAGAIN;
219
220 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
221
222 for (;;) {
223 if (signal_pending(current))
224 break;
225 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
226 timeout = MAX_SCHEDULE_TIMEOUT;
227 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
228 err = 0;
229 break;
230 }
231 }
232 finish_wait(sk_sleep(sk), &wait);
233
234 return err;
235 }
236
237 static void skcipher_wmem_wakeup(struct sock *sk)
238 {
239 struct socket_wq *wq;
240
241 if (!skcipher_writable(sk))
242 return;
243
244 rcu_read_lock();
245 wq = rcu_dereference(sk->sk_wq);
246 if (wq_has_sleeper(wq))
247 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
248 POLLRDNORM |
249 POLLRDBAND);
250 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
251 rcu_read_unlock();
252 }
253
254 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
255 {
256 struct alg_sock *ask = alg_sk(sk);
257 struct skcipher_ctx *ctx = ask->private;
258 long timeout;
259 DEFINE_WAIT(wait);
260 int err = -ERESTARTSYS;
261
262 if (flags & MSG_DONTWAIT) {
263 return -EAGAIN;
264 }
265
266 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
267
268 for (;;) {
269 if (signal_pending(current))
270 break;
271 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
272 timeout = MAX_SCHEDULE_TIMEOUT;
273 if (sk_wait_event(sk, &timeout, ctx->used)) {
274 err = 0;
275 break;
276 }
277 }
278 finish_wait(sk_sleep(sk), &wait);
279
280 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
281
282 return err;
283 }
284
285 static void skcipher_data_wakeup(struct sock *sk)
286 {
287 struct alg_sock *ask = alg_sk(sk);
288 struct skcipher_ctx *ctx = ask->private;
289 struct socket_wq *wq;
290
291 if (!ctx->used)
292 return;
293
294 rcu_read_lock();
295 wq = rcu_dereference(sk->sk_wq);
296 if (wq_has_sleeper(wq))
297 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
298 POLLRDNORM |
299 POLLRDBAND);
300 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
301 rcu_read_unlock();
302 }
303
304 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
305 size_t size)
306 {
307 struct sock *sk = sock->sk;
308 struct alg_sock *ask = alg_sk(sk);
309 struct skcipher_ctx *ctx = ask->private;
310 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
311 unsigned ivsize = crypto_skcipher_ivsize(tfm);
312 struct skcipher_sg_list *sgl;
313 struct af_alg_control con = {};
314 long copied = 0;
315 bool enc = 0;
316 bool init = 0;
317 int err;
318 int i;
319
320 if (msg->msg_controllen) {
321 err = af_alg_cmsg_send(msg, &con);
322 if (err)
323 return err;
324
325 init = 1;
326 switch (con.op) {
327 case ALG_OP_ENCRYPT:
328 enc = 1;
329 break;
330 case ALG_OP_DECRYPT:
331 enc = 0;
332 break;
333 default:
334 return -EINVAL;
335 }
336
337 if (con.iv && con.iv->ivlen != ivsize)
338 return -EINVAL;
339 }
340
341 err = -EINVAL;
342
343 lock_sock(sk);
344 if (!ctx->more && ctx->used)
345 goto unlock;
346
347 if (init) {
348 ctx->enc = enc;
349 if (con.iv)
350 memcpy(ctx->iv, con.iv->iv, ivsize);
351 }
352
353 while (size) {
354 struct scatterlist *sg;
355 unsigned long len = size;
356 size_t plen;
357
358 if (ctx->merge) {
359 sgl = list_entry(ctx->tsgl.prev,
360 struct skcipher_sg_list, list);
361 sg = sgl->sg + sgl->cur - 1;
362 len = min_t(unsigned long, len,
363 PAGE_SIZE - sg->offset - sg->length);
364
365 err = memcpy_from_msg(page_address(sg_page(sg)) +
366 sg->offset + sg->length,
367 msg, len);
368 if (err)
369 goto unlock;
370
371 sg->length += len;
372 ctx->merge = (sg->offset + sg->length) &
373 (PAGE_SIZE - 1);
374
375 ctx->used += len;
376 copied += len;
377 size -= len;
378 continue;
379 }
380
381 if (!skcipher_writable(sk)) {
382 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
383 if (err)
384 goto unlock;
385 }
386
387 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
388
389 err = skcipher_alloc_sgl(sk);
390 if (err)
391 goto unlock;
392
393 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
394 sg = sgl->sg;
395 sg_unmark_end(sg + sgl->cur);
396 do {
397 i = sgl->cur;
398 plen = min_t(size_t, len, PAGE_SIZE);
399
400 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
401 err = -ENOMEM;
402 if (!sg_page(sg + i))
403 goto unlock;
404
405 err = memcpy_from_msg(page_address(sg_page(sg + i)),
406 msg, plen);
407 if (err) {
408 __free_page(sg_page(sg + i));
409 sg_assign_page(sg + i, NULL);
410 goto unlock;
411 }
412
413 sg[i].length = plen;
414 len -= plen;
415 ctx->used += plen;
416 copied += plen;
417 size -= plen;
418 sgl->cur++;
419 } while (len && sgl->cur < MAX_SGL_ENTS);
420
421 if (!size)
422 sg_mark_end(sg + sgl->cur - 1);
423
424 ctx->merge = plen & (PAGE_SIZE - 1);
425 }
426
427 err = 0;
428
429 ctx->more = msg->msg_flags & MSG_MORE;
430
431 unlock:
432 skcipher_data_wakeup(sk);
433 release_sock(sk);
434
435 return copied ?: err;
436 }
437
438 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
439 int offset, size_t size, int flags)
440 {
441 struct sock *sk = sock->sk;
442 struct alg_sock *ask = alg_sk(sk);
443 struct skcipher_ctx *ctx = ask->private;
444 struct skcipher_sg_list *sgl;
445 int err = -EINVAL;
446
447 if (flags & MSG_SENDPAGE_NOTLAST)
448 flags |= MSG_MORE;
449
450 lock_sock(sk);
451 if (!ctx->more && ctx->used)
452 goto unlock;
453
454 if (!size)
455 goto done;
456
457 if (!skcipher_writable(sk)) {
458 err = skcipher_wait_for_wmem(sk, flags);
459 if (err)
460 goto unlock;
461 }
462
463 err = skcipher_alloc_sgl(sk);
464 if (err)
465 goto unlock;
466
467 ctx->merge = 0;
468 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
469
470 if (sgl->cur)
471 sg_unmark_end(sgl->sg + sgl->cur - 1);
472
473 sg_mark_end(sgl->sg + sgl->cur);
474 get_page(page);
475 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
476 sgl->cur++;
477 ctx->used += size;
478
479 done:
480 ctx->more = flags & MSG_MORE;
481
482 unlock:
483 skcipher_data_wakeup(sk);
484 release_sock(sk);
485
486 return err ?: size;
487 }
488
489 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
490 {
491 struct skcipher_sg_list *sgl;
492 struct scatterlist *sg;
493 int nents = 0;
494
495 list_for_each_entry(sgl, &ctx->tsgl, list) {
496 sg = sgl->sg;
497
498 while (!sg->length)
499 sg++;
500
501 nents += sg_nents(sg);
502 }
503 return nents;
504 }
505
506 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
507 int flags)
508 {
509 struct sock *sk = sock->sk;
510 struct alg_sock *ask = alg_sk(sk);
511 struct skcipher_ctx *ctx = ask->private;
512 struct skcipher_sg_list *sgl;
513 struct scatterlist *sg;
514 struct skcipher_async_req *sreq;
515 struct skcipher_request *req;
516 struct skcipher_async_rsgl *last_rsgl = NULL;
517 unsigned int txbufs = 0, len = 0, tx_nents = skcipher_all_sg_nents(ctx);
518 unsigned int reqlen = sizeof(struct skcipher_async_req) +
519 GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
520 int err = -ENOMEM;
521 bool mark = false;
522
523 lock_sock(sk);
524 req = kmalloc(reqlen, GFP_KERNEL);
525 if (unlikely(!req))
526 goto unlock;
527
528 sreq = GET_SREQ(req, ctx);
529 sreq->iocb = msg->msg_iocb;
530 memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl));
531 INIT_LIST_HEAD(&sreq->list);
532 sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
533 if (unlikely(!sreq->tsg)) {
534 kfree(req);
535 goto unlock;
536 }
537 sg_init_table(sreq->tsg, tx_nents);
538 memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
539 skcipher_request_set_tfm(req, crypto_skcipher_reqtfm(&ctx->req));
540 skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
541 skcipher_async_cb, sk);
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 goto free;
572
573 sg_init_table(tmp, tx_nents * 2);
574 for (x = 0; x < tx_nents; x++)
575 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
576 sreq->tsg[x].length,
577 sreq->tsg[x].offset);
578 kfree(sreq->tsg);
579 sreq->tsg = tmp;
580 tx_nents *= 2;
581 mark = true;
582 }
583 /* Need to take over the tx sgl from ctx
584 * to the asynch req - these sgls will be freed later */
585 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
586 sg->offset);
587
588 if (list_empty(&sreq->list)) {
589 rsgl = &sreq->first_sgl;
590 list_add_tail(&rsgl->list, &sreq->list);
591 } else {
592 rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
593 if (!rsgl) {
594 err = -ENOMEM;
595 goto free;
596 }
597 list_add_tail(&rsgl->list, &sreq->list);
598 }
599
600 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
601 err = used;
602 if (used < 0)
603 goto free;
604 if (last_rsgl)
605 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
606
607 last_rsgl = rsgl;
608 len += used;
609 skcipher_pull_sgl(sk, used, 0);
610 iov_iter_advance(&msg->msg_iter, used);
611 }
612
613 if (mark)
614 sg_mark_end(sreq->tsg + txbufs - 1);
615
616 skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
617 len, sreq->iv);
618 err = ctx->enc ? crypto_skcipher_encrypt(req) :
619 crypto_skcipher_decrypt(req);
620 if (err == -EINPROGRESS) {
621 atomic_inc(&ctx->inflight);
622 err = -EIOCBQUEUED;
623 goto unlock;
624 }
625 free:
626 skcipher_free_async_sgls(sreq);
627 kfree(req);
628 unlock:
629 skcipher_wmem_wakeup(sk);
630 release_sock(sk);
631 return err;
632 }
633
634 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
635 int flags)
636 {
637 struct sock *sk = sock->sk;
638 struct alg_sock *ask = alg_sk(sk);
639 struct skcipher_ctx *ctx = ask->private;
640 unsigned bs = crypto_skcipher_blocksize(crypto_skcipher_reqtfm(
641 &ctx->req));
642 struct skcipher_sg_list *sgl;
643 struct scatterlist *sg;
644 int err = -EAGAIN;
645 int used;
646 long copied = 0;
647
648 lock_sock(sk);
649 while (msg_data_left(msg)) {
650 sgl = list_first_entry(&ctx->tsgl,
651 struct skcipher_sg_list, list);
652 sg = sgl->sg;
653
654 while (!sg->length)
655 sg++;
656
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 skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
678 ctx->iv);
679
680 err = af_alg_wait_for_completion(
681 ctx->enc ?
682 crypto_skcipher_encrypt(&ctx->req) :
683 crypto_skcipher_decrypt(&ctx->req),
684 &ctx->completion);
685
686 free:
687 af_alg_free_sg(&ctx->rsgl);
688
689 if (err)
690 goto unlock;
691
692 copied += used;
693 skcipher_pull_sgl(sk, used, 1);
694 iov_iter_advance(&msg->msg_iter, used);
695 }
696
697 err = 0;
698
699 unlock:
700 skcipher_wmem_wakeup(sk);
701 release_sock(sk);
702
703 return copied ?: err;
704 }
705
706 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
707 size_t ignored, int flags)
708 {
709 return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
710 skcipher_recvmsg_async(sock, msg, flags) :
711 skcipher_recvmsg_sync(sock, msg, flags);
712 }
713
714 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
715 poll_table *wait)
716 {
717 struct sock *sk = sock->sk;
718 struct alg_sock *ask = alg_sk(sk);
719 struct skcipher_ctx *ctx = ask->private;
720 unsigned int mask;
721
722 sock_poll_wait(file, sk_sleep(sk), wait);
723 mask = 0;
724
725 if (ctx->used)
726 mask |= POLLIN | POLLRDNORM;
727
728 if (skcipher_writable(sk))
729 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
730
731 return mask;
732 }
733
734 static struct proto_ops algif_skcipher_ops = {
735 .family = PF_ALG,
736
737 .connect = sock_no_connect,
738 .socketpair = sock_no_socketpair,
739 .getname = sock_no_getname,
740 .ioctl = sock_no_ioctl,
741 .listen = sock_no_listen,
742 .shutdown = sock_no_shutdown,
743 .getsockopt = sock_no_getsockopt,
744 .mmap = sock_no_mmap,
745 .bind = sock_no_bind,
746 .accept = sock_no_accept,
747 .setsockopt = sock_no_setsockopt,
748
749 .release = af_alg_release,
750 .sendmsg = skcipher_sendmsg,
751 .sendpage = skcipher_sendpage,
752 .recvmsg = skcipher_recvmsg,
753 .poll = skcipher_poll,
754 };
755
756 static int skcipher_check_key(struct socket *sock)
757 {
758 int err;
759 struct sock *psk;
760 struct alg_sock *pask;
761 struct skcipher_tfm *tfm;
762 struct sock *sk = sock->sk;
763 struct alg_sock *ask = alg_sk(sk);
764
765 if (ask->refcnt)
766 return 0;
767
768 psk = ask->parent;
769 pask = alg_sk(ask->parent);
770 tfm = pask->private;
771
772 err = -ENOKEY;
773 lock_sock(psk);
774 if (!tfm->has_key)
775 goto unlock;
776
777 if (!pask->refcnt++)
778 sock_hold(psk);
779
780 ask->refcnt = 1;
781 sock_put(psk);
782
783 err = 0;
784
785 unlock:
786 release_sock(psk);
787
788 return err;
789 }
790
791 static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
792 size_t size)
793 {
794 int err;
795
796 err = skcipher_check_key(sock);
797 if (err)
798 return err;
799
800 return skcipher_sendmsg(sock, msg, size);
801 }
802
803 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
804 int offset, size_t size, int flags)
805 {
806 int err;
807
808 err = skcipher_check_key(sock);
809 if (err)
810 return err;
811
812 return skcipher_sendpage(sock, page, offset, size, flags);
813 }
814
815 static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
816 size_t ignored, int flags)
817 {
818 int err;
819
820 err = skcipher_check_key(sock);
821 if (err)
822 return err;
823
824 return skcipher_recvmsg(sock, msg, ignored, flags);
825 }
826
827 static struct proto_ops algif_skcipher_ops_nokey = {
828 .family = PF_ALG,
829
830 .connect = sock_no_connect,
831 .socketpair = sock_no_socketpair,
832 .getname = sock_no_getname,
833 .ioctl = sock_no_ioctl,
834 .listen = sock_no_listen,
835 .shutdown = sock_no_shutdown,
836 .getsockopt = sock_no_getsockopt,
837 .mmap = sock_no_mmap,
838 .bind = sock_no_bind,
839 .accept = sock_no_accept,
840 .setsockopt = sock_no_setsockopt,
841
842 .release = af_alg_release,
843 .sendmsg = skcipher_sendmsg_nokey,
844 .sendpage = skcipher_sendpage_nokey,
845 .recvmsg = skcipher_recvmsg_nokey,
846 .poll = skcipher_poll,
847 };
848
849 static void *skcipher_bind(const char *name, u32 type, u32 mask)
850 {
851 struct skcipher_tfm *tfm;
852 struct crypto_skcipher *skcipher;
853
854 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
855 if (!tfm)
856 return ERR_PTR(-ENOMEM);
857
858 skcipher = crypto_alloc_skcipher(name, type, mask);
859 if (IS_ERR(skcipher)) {
860 kfree(tfm);
861 return ERR_CAST(skcipher);
862 }
863
864 tfm->skcipher = skcipher;
865
866 return tfm;
867 }
868
869 static void skcipher_release(void *private)
870 {
871 struct skcipher_tfm *tfm = private;
872
873 crypto_free_skcipher(tfm->skcipher);
874 kfree(tfm);
875 }
876
877 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
878 {
879 struct skcipher_tfm *tfm = private;
880 int err;
881
882 err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
883 tfm->has_key = !err;
884
885 return err;
886 }
887
888 static void skcipher_wait(struct sock *sk)
889 {
890 struct alg_sock *ask = alg_sk(sk);
891 struct skcipher_ctx *ctx = ask->private;
892 int ctr = 0;
893
894 while (atomic_read(&ctx->inflight) && ctr++ < 100)
895 msleep(100);
896 }
897
898 static void skcipher_sock_destruct_common(struct sock *sk)
899 {
900 struct alg_sock *ask = alg_sk(sk);
901 struct skcipher_ctx *ctx = ask->private;
902 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
903
904 if (atomic_read(&ctx->inflight))
905 skcipher_wait(sk);
906
907 skcipher_free_sgl(sk);
908 sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
909 sock_kfree_s(sk, ctx, ctx->len);
910 }
911
912 static void skcipher_sock_destruct(struct sock *sk)
913 {
914 skcipher_sock_destruct_common(sk);
915 af_alg_release_parent(sk);
916 }
917
918 static void skcipher_release_parent_nokey(struct sock *sk)
919 {
920 struct alg_sock *ask = alg_sk(sk);
921
922 if (!ask->refcnt) {
923 sock_put(ask->parent);
924 return;
925 }
926
927 af_alg_release_parent(sk);
928 }
929
930 static void skcipher_sock_destruct_nokey(struct sock *sk)
931 {
932 skcipher_sock_destruct_common(sk);
933 skcipher_release_parent_nokey(sk);
934 }
935
936 static int skcipher_accept_parent_common(void *private, struct sock *sk)
937 {
938 struct skcipher_ctx *ctx;
939 struct alg_sock *ask = alg_sk(sk);
940 struct skcipher_tfm *tfm = private;
941 struct crypto_skcipher *skcipher = tfm->skcipher;
942 unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
943
944 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
945 if (!ctx)
946 return -ENOMEM;
947
948 ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
949 GFP_KERNEL);
950 if (!ctx->iv) {
951 sock_kfree_s(sk, ctx, len);
952 return -ENOMEM;
953 }
954
955 memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
956
957 INIT_LIST_HEAD(&ctx->tsgl);
958 ctx->len = len;
959 ctx->used = 0;
960 ctx->more = 0;
961 ctx->merge = 0;
962 ctx->enc = 0;
963 atomic_set(&ctx->inflight, 0);
964 af_alg_init_completion(&ctx->completion);
965
966 ask->private = ctx;
967
968 skcipher_request_set_tfm(&ctx->req, skcipher);
969 skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
970 af_alg_complete, &ctx->completion);
971
972 sk->sk_destruct = skcipher_sock_destruct;
973
974 return 0;
975 }
976
977 static int skcipher_accept_parent(void *private, struct sock *sk)
978 {
979 struct skcipher_tfm *tfm = private;
980
981 if (!tfm->has_key)
982 return -ENOKEY;
983
984 return skcipher_accept_parent_common(private, sk);
985 }
986
987 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
988 {
989 int err;
990
991 err = skcipher_accept_parent_common(private, sk);
992 if (err)
993 goto out;
994
995 sk->sk_destruct = skcipher_sock_destruct_nokey;
996
997 out:
998 return err;
999 }
1000
1001 static const struct af_alg_type algif_type_skcipher = {
1002 .bind = skcipher_bind,
1003 .release = skcipher_release,
1004 .setkey = skcipher_setkey,
1005 .accept = skcipher_accept_parent,
1006 .accept_nokey = skcipher_accept_parent_nokey,
1007 .ops = &algif_skcipher_ops,
1008 .ops_nokey = &algif_skcipher_ops_nokey,
1009 .name = "skcipher",
1010 .owner = THIS_MODULE
1011 };
1012
1013 static int __init algif_skcipher_init(void)
1014 {
1015 return af_alg_register_type(&algif_type_skcipher);
1016 }
1017
1018 static void __exit algif_skcipher_exit(void)
1019 {
1020 int err = af_alg_unregister_type(&algif_type_skcipher);
1021 BUG_ON(err);
1022 }
1023
1024 module_init(algif_skcipher_init);
1025 module_exit(algif_skcipher_exit);
1026 MODULE_LICENSE("GPL");