algif_skcipher.c 21.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
/*
 * algif_skcipher: User-space interface for skcipher algorithms
 *
 * This file provides the user-space API for symmetric key ciphers.
 *
 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/scatterwalk.h>
#include <crypto/skcipher.h>
#include <crypto/if_alg.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/kernel.h>
21
#include <linux/sched/signal.h>
22 23 24 25 26 27 28 29 30 31 32 33 34
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>

struct skcipher_sg_list {
	struct list_head list;

	int cur;

	struct scatterlist sg[0];
};

35 36 37 38 39
struct skcipher_tfm {
	struct crypto_skcipher *skcipher;
	bool has_key;
};

40 41 42 43 44 45 46 47
struct skcipher_ctx {
	struct list_head tsgl;
	struct af_alg_sgl rsgl;

	void *iv;

	struct af_alg_completion completion;

48
	atomic_t inflight;
49
	size_t used;
50 51 52 53 54 55

	unsigned int len;
	bool more;
	bool merge;
	bool enc;

56
	struct skcipher_request req;
57 58
};

59 60 61 62 63 64 65 66 67 68
struct skcipher_async_rsgl {
	struct af_alg_sgl sgl;
	struct list_head list;
};

struct skcipher_async_req {
	struct kiocb *iocb;
	struct skcipher_async_rsgl first_sgl;
	struct list_head list;
	struct scatterlist *tsg;
69 70
	atomic_t *inflight;
	struct skcipher_request req;
71 72
};

73
#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
74 75
		      sizeof(struct scatterlist) - 1)

76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
{
	struct skcipher_async_rsgl *rsgl, *tmp;
	struct scatterlist *sgl;
	struct scatterlist *sg;
	int i, n;

	list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
		af_alg_free_sg(&rsgl->sgl);
		if (rsgl != &sreq->first_sgl)
			kfree(rsgl);
	}
	sgl = sreq->tsg;
	n = sg_nents(sgl);
	for_each_sg(sgl, sg, n, i)
		put_page(sg_page(sg));

	kfree(sreq->tsg);
}

static void skcipher_async_cb(struct crypto_async_request *req, int err)
{
98
	struct skcipher_async_req *sreq = req->data;
99 100
	struct kiocb *iocb = sreq->iocb;

101
	atomic_dec(sreq->inflight);
102
	skcipher_free_async_sgls(sreq);
103
	kzfree(sreq);
Al Viro's avatar
Al Viro committed
104
	iocb->ki_complete(iocb, err, err);
105 106
}

107
static inline int skcipher_sndbuf(struct sock *sk)
108 109 110 111
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;

112 113 114 115 116 117 118
	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
			  ctx->used, 0);
}

static inline bool skcipher_writable(struct sock *sk)
{
	return PAGE_SIZE <= skcipher_sndbuf(sk);
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142
}

static int skcipher_alloc_sgl(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg = NULL;

	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
	if (!list_empty(&ctx->tsgl))
		sg = sgl->sg;

	if (!sg || sgl->cur >= MAX_SGL_ENTS) {
		sgl = sock_kmalloc(sk, sizeof(*sgl) +
				       sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
				   GFP_KERNEL);
		if (!sgl)
			return -ENOMEM;

		sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
		sgl->cur = 0;

		if (sg)
143
			sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
144 145 146 147 148 149 150

		list_add_tail(&sgl->list, &ctx->tsgl);
	}

	return 0;
}

151
static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
152 153 154 155 156 157 158 159 160 161 162 163 164
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	int i;

	while (!list_empty(&ctx->tsgl)) {
		sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
				       list);
		sg = sgl->sg;

		for (i = 0; i < sgl->cur; i++) {
165
			size_t plen = min_t(size_t, used, sg[i].length);
166 167 168 169 170 171 172 173 174 175 176 177

			if (!sg_page(sg + i))
				continue;

			sg[i].length -= plen;
			sg[i].offset += plen;

			used -= plen;
			ctx->used -= plen;

			if (sg[i].length)
				return;
178 179
			if (put)
				put_page(sg_page(sg + i));
180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
			sg_assign_page(sg + i, NULL);
		}

		list_del(&sgl->list);
		sock_kfree_s(sk, sgl,
			     sizeof(*sgl) + sizeof(sgl->sg[0]) *
					    (MAX_SGL_ENTS + 1));
	}

	if (!ctx->used)
		ctx->merge = 0;
}

static void skcipher_free_sgl(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;

198
	skcipher_pull_sgl(sk, ctx->used, 1);
199 200 201 202
}

static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
{
203
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
204
	int err = -ERESTARTSYS;
205
	long timeout;
206 207 208 209

	if (flags & MSG_DONTWAIT)
		return -EAGAIN;

210
	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
211

212
	add_wait_queue(sk_sleep(sk), &wait);
213 214 215 216
	for (;;) {
		if (signal_pending(current))
			break;
		timeout = MAX_SCHEDULE_TIMEOUT;
217
		if (sk_wait_event(sk, &timeout, skcipher_writable(sk), &wait)) {
218 219 220 221
			err = 0;
			break;
		}
	}
222
	remove_wait_queue(sk_sleep(sk), &wait);
223 224 225 226 227 228 229 230 231 232 233 234 235

	return err;
}

static void skcipher_wmem_wakeup(struct sock *sk)
{
	struct socket_wq *wq;

	if (!skcipher_writable(sk))
		return;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
236
	if (skwq_has_sleeper(wq))
237 238 239 240 241 242 243 244 245
		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
							   POLLRDNORM |
							   POLLRDBAND);
	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
	rcu_read_unlock();
}

static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
{
246
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
247 248 249 250 251 252 253 254 255
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	long timeout;
	int err = -ERESTARTSYS;

	if (flags & MSG_DONTWAIT) {
		return -EAGAIN;
	}

256
	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
257

258
	add_wait_queue(sk_sleep(sk), &wait);
259 260 261 262
	for (;;) {
		if (signal_pending(current))
			break;
		timeout = MAX_SCHEDULE_TIMEOUT;
263
		if (sk_wait_event(sk, &timeout, ctx->used, &wait)) {
264 265 266 267
			err = 0;
			break;
		}
	}
268
	remove_wait_queue(sk_sleep(sk), &wait);
269

270
	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285

	return err;
}

static void skcipher_data_wakeup(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct socket_wq *wq;

	if (!ctx->used)
		return;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
286
	if (skwq_has_sleeper(wq))
287 288 289 290 291 292 293
		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
							   POLLRDNORM |
							   POLLRDBAND);
	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	rcu_read_unlock();
}

294 295
static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
			    size_t size)
296 297 298
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
299 300
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
301
	struct skcipher_ctx *ctx = ask->private;
302 303
	struct skcipher_tfm *skc = pask->private;
	struct crypto_skcipher *tfm = skc->skcipher;
304
	unsigned ivsize = crypto_skcipher_ivsize(tfm);
305 306 307 308
	struct skcipher_sg_list *sgl;
	struct af_alg_control con = {};
	long copied = 0;
	bool enc = 0;
309
	bool init = 0;
310 311 312 313 314 315 316 317
	int err;
	int i;

	if (msg->msg_controllen) {
		err = af_alg_cmsg_send(msg, &con);
		if (err)
			return err;

318
		init = 1;
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339
		switch (con.op) {
		case ALG_OP_ENCRYPT:
			enc = 1;
			break;
		case ALG_OP_DECRYPT:
			enc = 0;
			break;
		default:
			return -EINVAL;
		}

		if (con.iv && con.iv->ivlen != ivsize)
			return -EINVAL;
	}

	err = -EINVAL;

	lock_sock(sk);
	if (!ctx->more && ctx->used)
		goto unlock;

340
	if (init) {
341 342 343 344 345 346 347 348
		ctx->enc = enc;
		if (con.iv)
			memcpy(ctx->iv, con.iv->iv, ivsize);
	}

	while (size) {
		struct scatterlist *sg;
		unsigned long len = size;
349
		size_t plen;
350 351 352 353 354 355 356 357

		if (ctx->merge) {
			sgl = list_entry(ctx->tsgl.prev,
					 struct skcipher_sg_list, list);
			sg = sgl->sg + sgl->cur - 1;
			len = min_t(unsigned long, len,
				    PAGE_SIZE - sg->offset - sg->length);

Al Viro's avatar
Al Viro committed
358 359 360
			err = memcpy_from_msg(page_address(sg_page(sg)) +
					      sg->offset + sg->length,
					      msg, len);
361 362 363 364 365 366 367 368 369 370 371 372 373
			if (err)
				goto unlock;

			sg->length += len;
			ctx->merge = (sg->offset + sg->length) &
				     (PAGE_SIZE - 1);

			ctx->used += len;
			copied += len;
			size -= len;
			continue;
		}

374
		if (!skcipher_writable(sk)) {
375 376 377 378 379
			err = skcipher_wait_for_wmem(sk, msg->msg_flags);
			if (err)
				goto unlock;
		}

380
		len = min_t(unsigned long, len, skcipher_sndbuf(sk));
381 382 383 384 385 386 387

		err = skcipher_alloc_sgl(sk);
		if (err)
			goto unlock;

		sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
		sg = sgl->sg;
388 389
		if (sgl->cur)
			sg_unmark_end(sg + sgl->cur - 1);
390 391
		do {
			i = sgl->cur;
392
			plen = min_t(size_t, len, PAGE_SIZE);
393 394 395 396 397 398

			sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
			err = -ENOMEM;
			if (!sg_page(sg + i))
				goto unlock;

Al Viro's avatar
Al Viro committed
399 400
			err = memcpy_from_msg(page_address(sg_page(sg + i)),
					      msg, plen);
401 402 403 404 405 406 407 408 409 410 411 412 413 414
			if (err) {
				__free_page(sg_page(sg + i));
				sg_assign_page(sg + i, NULL);
				goto unlock;
			}

			sg[i].length = plen;
			len -= plen;
			ctx->used += plen;
			copied += plen;
			size -= plen;
			sgl->cur++;
		} while (len && sgl->cur < MAX_SGL_ENTS);

415 416 417
		if (!size)
			sg_mark_end(sg + sgl->cur - 1);

418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
		ctx->merge = plen & (PAGE_SIZE - 1);
	}

	err = 0;

	ctx->more = msg->msg_flags & MSG_MORE;

unlock:
	skcipher_data_wakeup(sk);
	release_sock(sk);

	return copied ?: err;
}

static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
				 int offset, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct skcipher_sg_list *sgl;
	int err = -EINVAL;

441 442 443
	if (flags & MSG_SENDPAGE_NOTLAST)
		flags |= MSG_MORE;

444 445 446 447 448 449 450
	lock_sock(sk);
	if (!ctx->more && ctx->used)
		goto unlock;

	if (!size)
		goto done;

451
	if (!skcipher_writable(sk)) {
452 453 454 455 456 457 458 459 460 461 462 463
		err = skcipher_wait_for_wmem(sk, flags);
		if (err)
			goto unlock;
	}

	err = skcipher_alloc_sgl(sk);
	if (err)
		goto unlock;

	ctx->merge = 0;
	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);

464 465 466 467
	if (sgl->cur)
		sg_unmark_end(sgl->sg + sgl->cur - 1);

	sg_mark_end(sgl->sg + sgl->cur);
468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
	get_page(page);
	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
	sgl->cur++;
	ctx->used += size;

done:
	ctx->more = flags & MSG_MORE;

unlock:
	skcipher_data_wakeup(sk);
	release_sock(sk);

	return err ?: size;
}

483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504
static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
{
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	int nents = 0;

	list_for_each_entry(sgl, &ctx->tsgl, list) {
		sg = sgl->sg;

		while (!sg->length)
			sg++;

		nents += sg_nents(sg);
	}
	return nents;
}

static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
				  int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
505 506
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
507
	struct skcipher_ctx *ctx = ask->private;
508 509
	struct skcipher_tfm *skc = pask->private;
	struct crypto_skcipher *tfm = skc->skcipher;
510 511 512
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	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;
516 517
	unsigned int reqsize = crypto_skcipher_reqsize(tfm);
	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
518
	int err = -ENOMEM;
519
	bool mark = false;
520
	char *iv;
521

522 523 524
	sreq = kzalloc(sizeof(*sreq) + reqsize + ivsize, GFP_KERNEL);
	if (unlikely(!sreq))
		goto out;
525

526 527
	req = &sreq->req;
	iv = (char *)(req + 1) + reqsize;
528 529
	sreq->iocb = msg->msg_iocb;
	INIT_LIST_HEAD(&sreq->list);
530 531 532
	sreq->inflight = &ctx->inflight;

	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))
536 537
		goto unlock;
	sg_init_table(sreq->tsg, tx_nents);
538 539
	memcpy(iv, ctx->iv, ivsize);
	skcipher_request_set_tfm(req, tfm);
540
	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
541
				      skcipher_async_cb, sreq);
542 543 544

	while (iov_iter_count(&msg->msg_iter)) {
		struct skcipher_async_rsgl *rsgl;
545
		int used;
546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562

		if (!ctx->used) {
			err = skcipher_wait_for_data(sk, flags);
			if (err)
				goto free;
		}
		sgl = list_first_entry(&ctx->tsgl,
				       struct skcipher_sg_list, list);
		sg = sgl->sg;

		while (!sg->length)
			sg++;

		used = min_t(unsigned long, ctx->used,
			     iov_iter_count(&msg->msg_iter));
		used = min_t(unsigned long, used, sg->length);

563
		if (txbufs == tx_nents) {
564 565 566 567 568 569
			struct scatterlist *tmp;
			int x;
			/* Ran out of tx slots in async request
			 * need to expand */
			tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
				      GFP_KERNEL);
570 571
			if (!tmp) {
				err = -ENOMEM;
572
				goto free;
573
			}
574 575 576 577 578 579 580 581 582

			sg_init_table(tmp, tx_nents * 2);
			for (x = 0; x < tx_nents; x++)
				sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
					    sreq->tsg[x].length,
					    sreq->tsg[x].offset);
			kfree(sreq->tsg);
			sreq->tsg = tmp;
			tx_nents *= 2;
583
			mark = true;
584 585 586
		}
		/* Need to take over the tx sgl from ctx
		 * to the asynch req - these sgls will be freed later */
587
		sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
588 589 590 591 592 593
			    sg->offset);

		if (list_empty(&sreq->list)) {
			rsgl = &sreq->first_sgl;
			list_add_tail(&rsgl->list, &sreq->list);
		} else {
594
			rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614
			if (!rsgl) {
				err = -ENOMEM;
				goto free;
			}
			list_add_tail(&rsgl->list, &sreq->list);
		}

		used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
		err = used;
		if (used < 0)
			goto free;
		if (last_rsgl)
			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);

		last_rsgl = rsgl;
		len += used;
		skcipher_pull_sgl(sk, used, 0);
		iov_iter_advance(&msg->msg_iter, used);
	}

615 616 617
	if (mark)
		sg_mark_end(sreq->tsg + txbufs - 1);

618
	skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
619
				   len, iv);
620 621
	err = ctx->enc ? crypto_skcipher_encrypt(req) :
			 crypto_skcipher_decrypt(req);
622 623 624
	if (err == -EINPROGRESS) {
		atomic_inc(&ctx->inflight);
		err = -EIOCBQUEUED;
625
		sreq = NULL;
626 627 628 629 630 631 632
		goto unlock;
	}
free:
	skcipher_free_async_sgls(sreq);
unlock:
	skcipher_wmem_wakeup(sk);
	release_sock(sk);
633 634
	kzfree(sreq);
out:
635 636 637 638 639
	return err;
}

static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
				 int flags)
640 641 642
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
643 644
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
645
	struct skcipher_ctx *ctx = ask->private;
646 647 648
	struct skcipher_tfm *skc = pask->private;
	struct crypto_skcipher *tfm = skc->skcipher;
	unsigned bs = crypto_skcipher_blocksize(tfm);
649 650 651 652 653 654 655
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	int err = -EAGAIN;
	int used;
	long copied = 0;

	lock_sock(sk);
Al Viro's avatar
Al Viro committed
656
	while (msg_data_left(msg)) {
657
		if (!ctx->used) {
658 659
			err = skcipher_wait_for_data(sk, flags);
			if (err)
660
				goto unlock;
661 662
		}

Al Viro's avatar
Al Viro committed
663
		used = min_t(unsigned long, ctx->used, msg_data_left(msg));
664 665 666 667 668

		used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
		err = used;
		if (err < 0)
			goto unlock;
669

670 671
		if (ctx->more || used < ctx->used)
			used -= used % bs;
672

673 674 675
		err = -EINVAL;
		if (!used)
			goto free;
676

677 678 679 680 681 682 683
		sgl = list_first_entry(&ctx->tsgl,
				       struct skcipher_sg_list, list);
		sg = sgl->sg;

		while (!sg->length)
			sg++;

684 685
		skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
					   ctx->iv);
686

687
		err = af_alg_wait_for_completion(
688
				ctx->enc ?
689 690
					crypto_skcipher_encrypt(&ctx->req) :
					crypto_skcipher_decrypt(&ctx->req),
691 692
				&ctx->completion);

693
free:
694
		af_alg_free_sg(&ctx->rsgl);
695

696 697
		if (err)
			goto unlock;
698

699
		copied += used;
700
		skcipher_pull_sgl(sk, used, 1);
701
		iov_iter_advance(&msg->msg_iter, used);
702 703 704 705 706 707 708 709 710 711 712
	}

	err = 0;

unlock:
	skcipher_wmem_wakeup(sk);
	release_sock(sk);

	return copied ?: err;
}

713 714 715 716 717 718 719
static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
			    size_t ignored, int flags)
{
	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
		skcipher_recvmsg_async(sock, msg, flags) :
		skcipher_recvmsg_sync(sock, msg, flags);
}
720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762

static unsigned int skcipher_poll(struct file *file, struct socket *sock,
				  poll_table *wait)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	unsigned int mask;

	sock_poll_wait(file, sk_sleep(sk), wait);
	mask = 0;

	if (ctx->used)
		mask |= POLLIN | POLLRDNORM;

	if (skcipher_writable(sk))
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

	return mask;
}

static struct proto_ops algif_skcipher_ops = {
	.family		=	PF_ALG,

	.connect	=	sock_no_connect,
	.socketpair	=	sock_no_socketpair,
	.getname	=	sock_no_getname,
	.ioctl		=	sock_no_ioctl,
	.listen		=	sock_no_listen,
	.shutdown	=	sock_no_shutdown,
	.getsockopt	=	sock_no_getsockopt,
	.mmap		=	sock_no_mmap,
	.bind		=	sock_no_bind,
	.accept		=	sock_no_accept,
	.setsockopt	=	sock_no_setsockopt,

	.release	=	af_alg_release,
	.sendmsg	=	skcipher_sendmsg,
	.sendpage	=	skcipher_sendpage,
	.recvmsg	=	skcipher_recvmsg,
	.poll		=	skcipher_poll,
};

763 764
static int skcipher_check_key(struct socket *sock)
{
765
	int err = 0;
766 767 768 769 770 771
	struct sock *psk;
	struct alg_sock *pask;
	struct skcipher_tfm *tfm;
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);

772
	lock_sock(sk);
773
	if (ask->refcnt)
774
		goto unlock_child;
775 776 777 778 779 780

	psk = ask->parent;
	pask = alg_sk(ask->parent);
	tfm = pask->private;

	err = -ENOKEY;
781
	lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
782 783 784 785 786 787 788 789 790 791 792 793 794
	if (!tfm->has_key)
		goto unlock;

	if (!pask->refcnt++)
		sock_hold(psk);

	ask->refcnt = 1;
	sock_put(psk);

	err = 0;

unlock:
	release_sock(psk);
795 796
unlock_child:
	release_sock(sk);
797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858

	return err;
}

static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
				  size_t size)
{
	int err;

	err = skcipher_check_key(sock);
	if (err)
		return err;

	return skcipher_sendmsg(sock, msg, size);
}

static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
				       int offset, size_t size, int flags)
{
	int err;

	err = skcipher_check_key(sock);
	if (err)
		return err;

	return skcipher_sendpage(sock, page, offset, size, flags);
}

static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
				  size_t ignored, int flags)
{
	int err;

	err = skcipher_check_key(sock);
	if (err)
		return err;

	return skcipher_recvmsg(sock, msg, ignored, flags);
}

static struct proto_ops algif_skcipher_ops_nokey = {
	.family		=	PF_ALG,

	.connect	=	sock_no_connect,
	.socketpair	=	sock_no_socketpair,
	.getname	=	sock_no_getname,
	.ioctl		=	sock_no_ioctl,
	.listen		=	sock_no_listen,
	.shutdown	=	sock_no_shutdown,
	.getsockopt	=	sock_no_getsockopt,
	.mmap		=	sock_no_mmap,
	.bind		=	sock_no_bind,
	.accept		=	sock_no_accept,
	.setsockopt	=	sock_no_setsockopt,

	.release	=	af_alg_release,
	.sendmsg	=	skcipher_sendmsg_nokey,
	.sendpage	=	skcipher_sendpage_nokey,
	.recvmsg	=	skcipher_recvmsg_nokey,
	.poll		=	skcipher_poll,
};

859 860
static void *skcipher_bind(const char *name, u32 type, u32 mask)
{
861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876
	struct skcipher_tfm *tfm;
	struct crypto_skcipher *skcipher;

	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
	if (!tfm)
		return ERR_PTR(-ENOMEM);

	skcipher = crypto_alloc_skcipher(name, type, mask);
	if (IS_ERR(skcipher)) {
		kfree(tfm);
		return ERR_CAST(skcipher);
	}

	tfm->skcipher = skcipher;

	return tfm;
877 878 879 880
}

static void skcipher_release(void *private)
{
881 882 883 884
	struct skcipher_tfm *tfm = private;

	crypto_free_skcipher(tfm->skcipher);
	kfree(tfm);
885 886 887 888
}

static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
{
889 890 891 892 893 894 895
	struct skcipher_tfm *tfm = private;
	int err;

	err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
	tfm->has_key = !err;

	return err;
896 897
}

898 899 900 901 902 903 904 905 906 907
static void skcipher_wait(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	int ctr = 0;

	while (atomic_read(&ctx->inflight) && ctr++ < 100)
		msleep(100);
}

908 909 910 911
static void skcipher_sock_destruct(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
912
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
913

914 915 916
	if (atomic_read(&ctx->inflight))
		skcipher_wait(sk);

917
	skcipher_free_sgl(sk);
918
	sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
919 920 921 922
	sock_kfree_s(sk, ctx, ctx->len);
	af_alg_release_parent(sk);
}

923
static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
924 925 926
{
	struct skcipher_ctx *ctx;
	struct alg_sock *ask = alg_sk(sk);
927 928 929
	struct skcipher_tfm *tfm = private;
	struct crypto_skcipher *skcipher = tfm->skcipher;
	unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
930 931 932 933 934

	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

935
	ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
936 937 938 939 940 941
			       GFP_KERNEL);
	if (!ctx->iv) {
		sock_kfree_s(sk, ctx, len);
		return -ENOMEM;
	}

942
	memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
943 944 945 946 947 948 949

	INIT_LIST_HEAD(&ctx->tsgl);
	ctx->len = len;
	ctx->used = 0;
	ctx->more = 0;
	ctx->merge = 0;
	ctx->enc = 0;
950
	atomic_set(&ctx->inflight, 0);
951 952 953 954
	af_alg_init_completion(&ctx->completion);

	ask->private = ctx;

955
	skcipher_request_set_tfm(&ctx->req, skcipher);
956 957
	skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_SLEEP |
						 CRYPTO_TFM_REQ_MAY_BACKLOG,
958
				      af_alg_complete, &ctx->completion);
959 960 961 962 963 964

	sk->sk_destruct = skcipher_sock_destruct;

	return 0;
}

965 966 967 968
static int skcipher_accept_parent(void *private, struct sock *sk)
{
	struct skcipher_tfm *tfm = private;

969
	if (!tfm->has_key && crypto_skcipher_has_setkey(tfm->skcipher))
970 971
		return -ENOKEY;

972
	return skcipher_accept_parent_nokey(private, sk);
973 974
}

975 976 977 978 979
static const struct af_alg_type algif_type_skcipher = {
	.bind		=	skcipher_bind,
	.release	=	skcipher_release,
	.setkey		=	skcipher_setkey,
	.accept		=	skcipher_accept_parent,
980
	.accept_nokey	=	skcipher_accept_parent_nokey,
981
	.ops		=	&algif_skcipher_ops,
982
	.ops_nokey	=	&algif_skcipher_ops_nokey,
983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000
	.name		=	"skcipher",
	.owner		=	THIS_MODULE
};

static int __init algif_skcipher_init(void)
{
	return af_alg_register_type(&algif_type_skcipher);
}

static void __exit algif_skcipher_exit(void)
{
	int err = af_alg_unregister_type(&algif_type_skcipher);
	BUG_ON(err);
}

module_init(algif_skcipher_init);
module_exit(algif_skcipher_exit);
MODULE_LICENSE("GPL");