xref: /openbmc/linux/crypto/algif_aead.c (revision 95b384f9)
1 /*
2  * algif_aead: User-space interface for AEAD algorithms
3  *
4  * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>
5  *
6  * This file provides the user-space API for AEAD ciphers.
7  *
8  * This file is derived from algif_skcipher.c.
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 2 of the License, or (at your option)
13  * any later version.
14  */
15 
16 #include <crypto/internal/aead.h>
17 #include <crypto/scatterwalk.h>
18 #include <crypto/if_alg.h>
19 #include <linux/init.h>
20 #include <linux/list.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/module.h>
24 #include <linux/net.h>
25 #include <net/sock.h>
26 
27 struct aead_sg_list {
28 	unsigned int cur;
29 	struct scatterlist sg[ALG_MAX_PAGES];
30 };
31 
32 struct aead_async_rsgl {
33 	struct af_alg_sgl sgl;
34 	struct list_head list;
35 };
36 
37 struct aead_async_req {
38 	struct scatterlist *tsgl;
39 	struct aead_async_rsgl first_rsgl;
40 	struct list_head list;
41 	struct kiocb *iocb;
42 	unsigned int tsgls;
43 	char iv[];
44 };
45 
46 struct aead_ctx {
47 	struct aead_sg_list tsgl;
48 	struct aead_async_rsgl first_rsgl;
49 	struct list_head list;
50 
51 	void *iv;
52 
53 	struct af_alg_completion completion;
54 
55 	unsigned long used;
56 
57 	unsigned int len;
58 	bool more;
59 	bool merge;
60 	bool enc;
61 
62 	size_t aead_assoclen;
63 	struct aead_request aead_req;
64 };
65 
66 static inline int aead_sndbuf(struct sock *sk)
67 {
68 	struct alg_sock *ask = alg_sk(sk);
69 	struct aead_ctx *ctx = ask->private;
70 
71 	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
72 			  ctx->used, 0);
73 }
74 
75 static inline bool aead_writable(struct sock *sk)
76 {
77 	return PAGE_SIZE <= aead_sndbuf(sk);
78 }
79 
80 static inline bool aead_sufficient_data(struct aead_ctx *ctx)
81 {
82 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
83 
84 	return ctx->used >= ctx->aead_assoclen + as;
85 }
86 
87 static void aead_reset_ctx(struct aead_ctx *ctx)
88 {
89 	struct aead_sg_list *sgl = &ctx->tsgl;
90 
91 	sg_init_table(sgl->sg, ALG_MAX_PAGES);
92 	sgl->cur = 0;
93 	ctx->used = 0;
94 	ctx->more = 0;
95 	ctx->merge = 0;
96 }
97 
98 static void aead_put_sgl(struct sock *sk)
99 {
100 	struct alg_sock *ask = alg_sk(sk);
101 	struct aead_ctx *ctx = ask->private;
102 	struct aead_sg_list *sgl = &ctx->tsgl;
103 	struct scatterlist *sg = sgl->sg;
104 	unsigned int i;
105 
106 	for (i = 0; i < sgl->cur; i++) {
107 		if (!sg_page(sg + i))
108 			continue;
109 
110 		put_page(sg_page(sg + i));
111 		sg_assign_page(sg + i, NULL);
112 	}
113 	aead_reset_ctx(ctx);
114 }
115 
116 static void aead_wmem_wakeup(struct sock *sk)
117 {
118 	struct socket_wq *wq;
119 
120 	if (!aead_writable(sk))
121 		return;
122 
123 	rcu_read_lock();
124 	wq = rcu_dereference(sk->sk_wq);
125 	if (skwq_has_sleeper(wq))
126 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
127 							   POLLRDNORM |
128 							   POLLRDBAND);
129 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
130 	rcu_read_unlock();
131 }
132 
133 static int aead_wait_for_data(struct sock *sk, unsigned flags)
134 {
135 	struct alg_sock *ask = alg_sk(sk);
136 	struct aead_ctx *ctx = ask->private;
137 	long timeout;
138 	DEFINE_WAIT(wait);
139 	int err = -ERESTARTSYS;
140 
141 	if (flags & MSG_DONTWAIT)
142 		return -EAGAIN;
143 
144 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
145 
146 	for (;;) {
147 		if (signal_pending(current))
148 			break;
149 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
150 		timeout = MAX_SCHEDULE_TIMEOUT;
151 		if (sk_wait_event(sk, &timeout, !ctx->more)) {
152 			err = 0;
153 			break;
154 		}
155 	}
156 	finish_wait(sk_sleep(sk), &wait);
157 
158 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
159 
160 	return err;
161 }
162 
163 static void aead_data_wakeup(struct sock *sk)
164 {
165 	struct alg_sock *ask = alg_sk(sk);
166 	struct aead_ctx *ctx = ask->private;
167 	struct socket_wq *wq;
168 
169 	if (ctx->more)
170 		return;
171 	if (!ctx->used)
172 		return;
173 
174 	rcu_read_lock();
175 	wq = rcu_dereference(sk->sk_wq);
176 	if (skwq_has_sleeper(wq))
177 		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
178 							   POLLRDNORM |
179 							   POLLRDBAND);
180 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
181 	rcu_read_unlock();
182 }
183 
184 static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
185 {
186 	struct sock *sk = sock->sk;
187 	struct alg_sock *ask = alg_sk(sk);
188 	struct aead_ctx *ctx = ask->private;
189 	unsigned ivsize =
190 		crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
191 	struct aead_sg_list *sgl = &ctx->tsgl;
192 	struct af_alg_control con = {};
193 	long copied = 0;
194 	bool enc = 0;
195 	bool init = 0;
196 	int err = -EINVAL;
197 
198 	if (msg->msg_controllen) {
199 		err = af_alg_cmsg_send(msg, &con);
200 		if (err)
201 			return err;
202 
203 		init = 1;
204 		switch (con.op) {
205 		case ALG_OP_ENCRYPT:
206 			enc = 1;
207 			break;
208 		case ALG_OP_DECRYPT:
209 			enc = 0;
210 			break;
211 		default:
212 			return -EINVAL;
213 		}
214 
215 		if (con.iv && con.iv->ivlen != ivsize)
216 			return -EINVAL;
217 	}
218 
219 	lock_sock(sk);
220 	if (!ctx->more && ctx->used)
221 		goto unlock;
222 
223 	if (init) {
224 		ctx->enc = enc;
225 		if (con.iv)
226 			memcpy(ctx->iv, con.iv->iv, ivsize);
227 
228 		ctx->aead_assoclen = con.aead_assoclen;
229 	}
230 
231 	while (size) {
232 		size_t len = size;
233 		struct scatterlist *sg = NULL;
234 
235 		/* use the existing memory in an allocated page */
236 		if (ctx->merge) {
237 			sg = sgl->sg + sgl->cur - 1;
238 			len = min_t(unsigned long, len,
239 				    PAGE_SIZE - sg->offset - sg->length);
240 			err = memcpy_from_msg(page_address(sg_page(sg)) +
241 					      sg->offset + sg->length,
242 					      msg, len);
243 			if (err)
244 				goto unlock;
245 
246 			sg->length += len;
247 			ctx->merge = (sg->offset + sg->length) &
248 				     (PAGE_SIZE - 1);
249 
250 			ctx->used += len;
251 			copied += len;
252 			size -= len;
253 			continue;
254 		}
255 
256 		if (!aead_writable(sk)) {
257 			/* user space sent too much data */
258 			aead_put_sgl(sk);
259 			err = -EMSGSIZE;
260 			goto unlock;
261 		}
262 
263 		/* allocate a new page */
264 		len = min_t(unsigned long, size, aead_sndbuf(sk));
265 		while (len) {
266 			size_t plen = 0;
267 
268 			if (sgl->cur >= ALG_MAX_PAGES) {
269 				aead_put_sgl(sk);
270 				err = -E2BIG;
271 				goto unlock;
272 			}
273 
274 			sg = sgl->sg + sgl->cur;
275 			plen = min_t(size_t, len, PAGE_SIZE);
276 
277 			sg_assign_page(sg, alloc_page(GFP_KERNEL));
278 			err = -ENOMEM;
279 			if (!sg_page(sg))
280 				goto unlock;
281 
282 			err = memcpy_from_msg(page_address(sg_page(sg)),
283 					      msg, plen);
284 			if (err) {
285 				__free_page(sg_page(sg));
286 				sg_assign_page(sg, NULL);
287 				goto unlock;
288 			}
289 
290 			sg->offset = 0;
291 			sg->length = plen;
292 			len -= plen;
293 			ctx->used += plen;
294 			copied += plen;
295 			sgl->cur++;
296 			size -= plen;
297 			ctx->merge = plen & (PAGE_SIZE - 1);
298 		}
299 	}
300 
301 	err = 0;
302 
303 	ctx->more = msg->msg_flags & MSG_MORE;
304 	if (!ctx->more && !aead_sufficient_data(ctx)) {
305 		aead_put_sgl(sk);
306 		err = -EMSGSIZE;
307 	}
308 
309 unlock:
310 	aead_data_wakeup(sk);
311 	release_sock(sk);
312 
313 	return err ?: copied;
314 }
315 
316 static ssize_t aead_sendpage(struct socket *sock, struct page *page,
317 			     int offset, size_t size, int flags)
318 {
319 	struct sock *sk = sock->sk;
320 	struct alg_sock *ask = alg_sk(sk);
321 	struct aead_ctx *ctx = ask->private;
322 	struct aead_sg_list *sgl = &ctx->tsgl;
323 	int err = -EINVAL;
324 
325 	if (flags & MSG_SENDPAGE_NOTLAST)
326 		flags |= MSG_MORE;
327 
328 	if (sgl->cur >= ALG_MAX_PAGES)
329 		return -E2BIG;
330 
331 	lock_sock(sk);
332 	if (!ctx->more && ctx->used)
333 		goto unlock;
334 
335 	if (!size)
336 		goto done;
337 
338 	if (!aead_writable(sk)) {
339 		/* user space sent too much data */
340 		aead_put_sgl(sk);
341 		err = -EMSGSIZE;
342 		goto unlock;
343 	}
344 
345 	ctx->merge = 0;
346 
347 	get_page(page);
348 	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
349 	sgl->cur++;
350 	ctx->used += size;
351 
352 	err = 0;
353 
354 done:
355 	ctx->more = flags & MSG_MORE;
356 	if (!ctx->more && !aead_sufficient_data(ctx)) {
357 		aead_put_sgl(sk);
358 		err = -EMSGSIZE;
359 	}
360 
361 unlock:
362 	aead_data_wakeup(sk);
363 	release_sock(sk);
364 
365 	return err ?: size;
366 }
367 
368 #define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \
369 		((char *)req + sizeof(struct aead_request) + \
370 		 crypto_aead_reqsize(tfm))
371 
372  #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \
373 	crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \
374 	sizeof(struct aead_request)
375 
376 static void aead_async_cb(struct crypto_async_request *_req, int err)
377 {
378 	struct sock *sk = _req->data;
379 	struct alg_sock *ask = alg_sk(sk);
380 	struct aead_ctx *ctx = ask->private;
381 	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
382 	struct aead_request *req = aead_request_cast(_req);
383 	struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);
384 	struct scatterlist *sg = areq->tsgl;
385 	struct aead_async_rsgl *rsgl;
386 	struct kiocb *iocb = areq->iocb;
387 	unsigned int i, reqlen = GET_REQ_SIZE(tfm);
388 
389 	list_for_each_entry(rsgl, &areq->list, list) {
390 		af_alg_free_sg(&rsgl->sgl);
391 		if (rsgl != &areq->first_rsgl)
392 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
393 	}
394 
395 	for (i = 0; i < areq->tsgls; i++)
396 		put_page(sg_page(sg + i));
397 
398 	sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
399 	sock_kfree_s(sk, req, reqlen);
400 	__sock_put(sk);
401 	iocb->ki_complete(iocb, err, err);
402 }
403 
404 static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg,
405 			      int flags)
406 {
407 	struct sock *sk = sock->sk;
408 	struct alg_sock *ask = alg_sk(sk);
409 	struct aead_ctx *ctx = ask->private;
410 	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
411 	struct aead_async_req *areq;
412 	struct aead_request *req = NULL;
413 	struct aead_sg_list *sgl = &ctx->tsgl;
414 	struct aead_async_rsgl *last_rsgl = NULL, *rsgl;
415 	unsigned int as = crypto_aead_authsize(tfm);
416 	unsigned int i, reqlen = GET_REQ_SIZE(tfm);
417 	int err = -ENOMEM;
418 	unsigned long used;
419 	size_t outlen;
420 	size_t usedpages = 0;
421 
422 	lock_sock(sk);
423 	if (ctx->more) {
424 		err = aead_wait_for_data(sk, flags);
425 		if (err)
426 			goto unlock;
427 	}
428 
429 	used = ctx->used;
430 	outlen = used;
431 
432 	if (!aead_sufficient_data(ctx))
433 		goto unlock;
434 
435 	req = sock_kmalloc(sk, reqlen, GFP_KERNEL);
436 	if (unlikely(!req))
437 		goto unlock;
438 
439 	areq = GET_ASYM_REQ(req, tfm);
440 	memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));
441 	INIT_LIST_HEAD(&areq->list);
442 	areq->iocb = msg->msg_iocb;
443 	memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));
444 	aead_request_set_tfm(req, tfm);
445 	aead_request_set_ad(req, ctx->aead_assoclen);
446 	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
447 				  aead_async_cb, sk);
448 	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);
449 
450 	/* take over all tx sgls from ctx */
451 	areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * sgl->cur,
452 				  GFP_KERNEL);
453 	if (unlikely(!areq->tsgl))
454 		goto free;
455 
456 	sg_init_table(areq->tsgl, sgl->cur);
457 	for (i = 0; i < sgl->cur; i++)
458 		sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]),
459 			    sgl->sg[i].length, sgl->sg[i].offset);
460 
461 	areq->tsgls = sgl->cur;
462 
463 	/* create rx sgls */
464 	while (iov_iter_count(&msg->msg_iter)) {
465 		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
466 				      (outlen - usedpages));
467 
468 		if (list_empty(&areq->list)) {
469 			rsgl = &areq->first_rsgl;
470 
471 		} else {
472 			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
473 			if (unlikely(!rsgl)) {
474 				err = -ENOMEM;
475 				goto free;
476 			}
477 		}
478 		rsgl->sgl.npages = 0;
479 		list_add_tail(&rsgl->list, &areq->list);
480 
481 		/* make one iovec available as scatterlist */
482 		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
483 		if (err < 0)
484 			goto free;
485 
486 		usedpages += err;
487 
488 		/* chain the new scatterlist with previous one */
489 		if (last_rsgl)
490 			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
491 
492 		last_rsgl = rsgl;
493 
494 		/* we do not need more iovecs as we have sufficient memory */
495 		if (outlen <= usedpages)
496 			break;
497 
498 		iov_iter_advance(&msg->msg_iter, err);
499 	}
500 	err = -EINVAL;
501 	/* ensure output buffer is sufficiently large */
502 	if (usedpages < outlen)
503 		goto free;
504 
505 	aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used,
506 			       areq->iv);
507 	err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
508 	if (err) {
509 		if (err == -EINPROGRESS) {
510 			sock_hold(sk);
511 			err = -EIOCBQUEUED;
512 			aead_reset_ctx(ctx);
513 			goto unlock;
514 		} else if (err == -EBADMSG) {
515 			aead_put_sgl(sk);
516 		}
517 		goto free;
518 	}
519 	aead_put_sgl(sk);
520 
521 free:
522 	list_for_each_entry(rsgl, &areq->list, list) {
523 		af_alg_free_sg(&rsgl->sgl);
524 		if (rsgl != &areq->first_rsgl)
525 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
526 	}
527 	if (areq->tsgl)
528 		sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
529 	if (req)
530 		sock_kfree_s(sk, req, reqlen);
531 unlock:
532 	aead_wmem_wakeup(sk);
533 	release_sock(sk);
534 	return err ? err : outlen;
535 }
536 
537 static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags)
538 {
539 	struct sock *sk = sock->sk;
540 	struct alg_sock *ask = alg_sk(sk);
541 	struct aead_ctx *ctx = ask->private;
542 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
543 	struct aead_sg_list *sgl = &ctx->tsgl;
544 	struct aead_async_rsgl *last_rsgl = NULL;
545 	struct aead_async_rsgl *rsgl, *tmp;
546 	int err = -EINVAL;
547 	unsigned long used = 0;
548 	size_t outlen = 0;
549 	size_t usedpages = 0;
550 
551 	lock_sock(sk);
552 
553 	/*
554 	 * AEAD memory structure: For encryption, the tag is appended to the
555 	 * ciphertext which implies that the memory allocated for the ciphertext
556 	 * must be increased by the tag length. For decryption, the tag
557 	 * is expected to be concatenated to the ciphertext. The plaintext
558 	 * therefore has a memory size of the ciphertext minus the tag length.
559 	 *
560 	 * The memory structure for cipher operation has the following
561 	 * structure:
562 	 *	AEAD encryption input:  assoc data || plaintext
563 	 *	AEAD encryption output: cipherntext || auth tag
564 	 *	AEAD decryption input:  assoc data || ciphertext || auth tag
565 	 *	AEAD decryption output: plaintext
566 	 */
567 
568 	if (ctx->more) {
569 		err = aead_wait_for_data(sk, flags);
570 		if (err)
571 			goto unlock;
572 	}
573 
574 	used = ctx->used;
575 
576 	/*
577 	 * Make sure sufficient data is present -- note, the same check is
578 	 * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
579 	 * shall provide an information to the data sender that something is
580 	 * wrong, but they are irrelevant to maintain the kernel integrity.
581 	 * We need this check here too in case user space decides to not honor
582 	 * the error message in sendmsg/sendpage and still call recvmsg. This
583 	 * check here protects the kernel integrity.
584 	 */
585 	if (!aead_sufficient_data(ctx))
586 		goto unlock;
587 
588 	outlen = used;
589 
590 	/*
591 	 * The cipher operation input data is reduced by the associated data
592 	 * length as this data is processed separately later on.
593 	 */
594 	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);
595 
596 	/* convert iovecs of output buffers into scatterlists */
597 	while (iov_iter_count(&msg->msg_iter)) {
598 		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
599 				      (outlen - usedpages));
600 
601 		if (list_empty(&ctx->list)) {
602 			rsgl = &ctx->first_rsgl;
603 		} else {
604 			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
605 			if (unlikely(!rsgl)) {
606 				err = -ENOMEM;
607 				goto unlock;
608 			}
609 		}
610 		rsgl->sgl.npages = 0;
611 		list_add_tail(&rsgl->list, &ctx->list);
612 
613 		/* make one iovec available as scatterlist */
614 		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
615 		if (err < 0)
616 			goto unlock;
617 		usedpages += err;
618 		/* chain the new scatterlist with previous one */
619 		if (last_rsgl)
620 			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
621 
622 		last_rsgl = rsgl;
623 
624 		/* we do not need more iovecs as we have sufficient memory */
625 		if (outlen <= usedpages)
626 			break;
627 		iov_iter_advance(&msg->msg_iter, err);
628 	}
629 
630 	err = -EINVAL;
631 	/* ensure output buffer is sufficiently large */
632 	if (usedpages < outlen)
633 		goto unlock;
634 
635 	sg_mark_end(sgl->sg + sgl->cur - 1);
636 	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
637 			       used, ctx->iv);
638 	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
639 
640 	err = af_alg_wait_for_completion(ctx->enc ?
641 					 crypto_aead_encrypt(&ctx->aead_req) :
642 					 crypto_aead_decrypt(&ctx->aead_req),
643 					 &ctx->completion);
644 
645 	if (err) {
646 		/* EBADMSG implies a valid cipher operation took place */
647 		if (err == -EBADMSG)
648 			aead_put_sgl(sk);
649 
650 		goto unlock;
651 	}
652 
653 	aead_put_sgl(sk);
654 	err = 0;
655 
656 unlock:
657 	list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) {
658 		af_alg_free_sg(&rsgl->sgl);
659 		if (rsgl != &ctx->first_rsgl)
660 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
661 		list_del(&rsgl->list);
662 	}
663 	INIT_LIST_HEAD(&ctx->list);
664 	aead_wmem_wakeup(sk);
665 	release_sock(sk);
666 
667 	return err ? err : outlen;
668 }
669 
670 static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
671 			int flags)
672 {
673 	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
674 		aead_recvmsg_async(sock, msg, flags) :
675 		aead_recvmsg_sync(sock, msg, flags);
676 }
677 
678 static unsigned int aead_poll(struct file *file, struct socket *sock,
679 			      poll_table *wait)
680 {
681 	struct sock *sk = sock->sk;
682 	struct alg_sock *ask = alg_sk(sk);
683 	struct aead_ctx *ctx = ask->private;
684 	unsigned int mask;
685 
686 	sock_poll_wait(file, sk_sleep(sk), wait);
687 	mask = 0;
688 
689 	if (!ctx->more)
690 		mask |= POLLIN | POLLRDNORM;
691 
692 	if (aead_writable(sk))
693 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
694 
695 	return mask;
696 }
697 
698 static struct proto_ops algif_aead_ops = {
699 	.family		=	PF_ALG,
700 
701 	.connect	=	sock_no_connect,
702 	.socketpair	=	sock_no_socketpair,
703 	.getname	=	sock_no_getname,
704 	.ioctl		=	sock_no_ioctl,
705 	.listen		=	sock_no_listen,
706 	.shutdown	=	sock_no_shutdown,
707 	.getsockopt	=	sock_no_getsockopt,
708 	.mmap		=	sock_no_mmap,
709 	.bind		=	sock_no_bind,
710 	.accept		=	sock_no_accept,
711 	.setsockopt	=	sock_no_setsockopt,
712 
713 	.release	=	af_alg_release,
714 	.sendmsg	=	aead_sendmsg,
715 	.sendpage	=	aead_sendpage,
716 	.recvmsg	=	aead_recvmsg,
717 	.poll		=	aead_poll,
718 };
719 
720 static void *aead_bind(const char *name, u32 type, u32 mask)
721 {
722 	return crypto_alloc_aead(name, type, mask);
723 }
724 
725 static void aead_release(void *private)
726 {
727 	crypto_free_aead(private);
728 }
729 
730 static int aead_setauthsize(void *private, unsigned int authsize)
731 {
732 	return crypto_aead_setauthsize(private, authsize);
733 }
734 
735 static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
736 {
737 	return crypto_aead_setkey(private, key, keylen);
738 }
739 
740 static void aead_sock_destruct(struct sock *sk)
741 {
742 	struct alg_sock *ask = alg_sk(sk);
743 	struct aead_ctx *ctx = ask->private;
744 	unsigned int ivlen = crypto_aead_ivsize(
745 				crypto_aead_reqtfm(&ctx->aead_req));
746 
747 	WARN_ON(atomic_read(&sk->sk_refcnt) != 0);
748 	aead_put_sgl(sk);
749 	sock_kzfree_s(sk, ctx->iv, ivlen);
750 	sock_kfree_s(sk, ctx, ctx->len);
751 	af_alg_release_parent(sk);
752 }
753 
754 static int aead_accept_parent(void *private, struct sock *sk)
755 {
756 	struct aead_ctx *ctx;
757 	struct alg_sock *ask = alg_sk(sk);
758 	unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private);
759 	unsigned int ivlen = crypto_aead_ivsize(private);
760 
761 	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
762 	if (!ctx)
763 		return -ENOMEM;
764 	memset(ctx, 0, len);
765 
766 	ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL);
767 	if (!ctx->iv) {
768 		sock_kfree_s(sk, ctx, len);
769 		return -ENOMEM;
770 	}
771 	memset(ctx->iv, 0, ivlen);
772 
773 	ctx->len = len;
774 	ctx->used = 0;
775 	ctx->more = 0;
776 	ctx->merge = 0;
777 	ctx->enc = 0;
778 	ctx->tsgl.cur = 0;
779 	ctx->aead_assoclen = 0;
780 	af_alg_init_completion(&ctx->completion);
781 	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
782 	INIT_LIST_HEAD(&ctx->list);
783 
784 	ask->private = ctx;
785 
786 	aead_request_set_tfm(&ctx->aead_req, private);
787 	aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
788 				  af_alg_complete, &ctx->completion);
789 
790 	sk->sk_destruct = aead_sock_destruct;
791 
792 	return 0;
793 }
794 
795 static const struct af_alg_type algif_type_aead = {
796 	.bind		=	aead_bind,
797 	.release	=	aead_release,
798 	.setkey		=	aead_setkey,
799 	.setauthsize	=	aead_setauthsize,
800 	.accept		=	aead_accept_parent,
801 	.ops		=	&algif_aead_ops,
802 	.name		=	"aead",
803 	.owner		=	THIS_MODULE
804 };
805 
806 static int __init algif_aead_init(void)
807 {
808 	return af_alg_register_type(&algif_type_aead);
809 }
810 
811 static void __exit algif_aead_exit(void)
812 {
813 	int err = af_alg_unregister_type(&algif_type_aead);
814 	BUG_ON(err);
815 }
816 
817 module_init(algif_aead_init);
818 module_exit(algif_aead_exit);
819 MODULE_LICENSE("GPL");
820 MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
821 MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");
822