[linux-2.6-block.git] / crypto / algif_skcipher.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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>
 *
 * The following concept of the memory management is used:
 *
 * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
 * filled by user space with the data submitted via sendmsg. Filling up the TX
 * SGL does not cause a crypto operation -- the data will only be tracked by
 * the kernel. Upon receipt of one recvmsg call, the caller must provide a
 * buffer which is tracked with the RX SGL.
 *
 * During the processing of the recvmsg operation, the cipher request is
 * allocated and prepared. As part of the recvmsg operation, the processed
 * TX buffers are extracted from the TX SGL into a separate SGL.
 *
 * After the completion of the crypto operation, the RX SGL and the cipher
 * request is released. The extracted TX SGL parts are released together with
 * the RX SGL release.
 */

#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>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>

static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
			    size_t size)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
	struct crypto_skcipher *tfm = pask->private;
	unsigned ivsize = crypto_skcipher_ivsize(tfm);

	return af_alg_sendmsg(sock, msg, size, ivsize);
}

static int algif_skcipher_export(struct sock *sk, struct skcipher_request *req)
{
	struct alg_sock *ask = alg_sk(sk);
	struct crypto_skcipher *tfm;
	struct af_alg_ctx *ctx;
	struct alg_sock *pask;
	unsigned statesize;
	struct sock *psk;
	int err;

	if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL))
		return 0;

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

	statesize = crypto_skcipher_statesize(tfm);
	ctx->state = sock_kmalloc(sk, statesize, GFP_ATOMIC);
	if (!ctx->state)
		return -ENOMEM;

	err = crypto_skcipher_export(req, ctx->state);
	if (err) {
		sock_kzfree_s(sk, ctx->state, statesize);
		ctx->state = NULL;
	}

	return err;
}

static void algif_skcipher_done(void *data, int err)
{
	struct af_alg_async_req *areq = data;
	struct sock *sk = areq->sk;

	if (err)
		goto out;

	err = algif_skcipher_export(sk, &areq->cra_u.skcipher_req);

out:
	af_alg_async_cb(data, err);
}

static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
			     size_t ignored, int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
	struct af_alg_ctx *ctx = ask->private;
	struct crypto_skcipher *tfm = pask->private;
	unsigned int bs = crypto_skcipher_chunksize(tfm);
	struct af_alg_async_req *areq;
	unsigned cflags = 0;
	int err = 0;
	size_t len = 0;

	if (!ctx->init || (ctx->more && ctx->used < bs)) {
		err = af_alg_wait_for_data(sk, flags, bs);
		if (err)
			return err;
	}

	/* Allocate cipher request for current operation. */
	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
				     crypto_skcipher_reqsize(tfm));
	if (IS_ERR(areq))
		return PTR_ERR(areq);

	/* convert iovecs of output buffers into RX SGL */
	err = af_alg_get_rsgl(sk, msg, flags, areq, ctx->used, &len);
	if (err)
		goto free;

	/*
	 * If more buffers are to be expected to be processed, process only
	 * full block size buffers.
	 */
	if (ctx->more || len < ctx->used) {
		len -= len % bs;
		cflags |= CRYPTO_SKCIPHER_REQ_NOTFINAL;
	}

	/*
	 * Create a per request TX SGL for this request which tracks the
	 * SG entries from the global TX SGL.
	 */
	areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
	if (!areq->tsgl_entries)
		areq->tsgl_entries = 1;
	areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
						 areq->tsgl_entries),
				  GFP_KERNEL);
	if (!areq->tsgl) {
		err = -ENOMEM;
		goto free;
	}
	sg_init_table(areq->tsgl, areq->tsgl_entries);
	af_alg_pull_tsgl(sk, len, areq->tsgl, 0);

	/* Initialize the crypto operation */
	skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
	skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
				   areq->first_rsgl.sgl.sgt.sgl, len, ctx->iv);

	if (ctx->state) {
		err = crypto_skcipher_import(&areq->cra_u.skcipher_req,
					     ctx->state);
		sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));
		ctx->state = NULL;
		if (err)
			goto free;
		cflags |= CRYPTO_SKCIPHER_REQ_CONT;
	}

	if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
		/* AIO operation */
		sock_hold(sk);
		areq->iocb = msg->msg_iocb;

		/* Remember output size that will be generated. */
		areq->outlen = len;

		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
					      cflags |
					      CRYPTO_TFM_REQ_MAY_SLEEP,
					      algif_skcipher_done, areq);
		err = ctx->enc ?
			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);

		/* AIO operation in progress */
		if (err == -EINPROGRESS)
			return -EIOCBQUEUED;

		sock_put(sk);
	} else {
		/* Synchronous operation */
		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
					      cflags |
					      CRYPTO_TFM_REQ_MAY_SLEEP |
					      CRYPTO_TFM_REQ_MAY_BACKLOG,
					      crypto_req_done, &ctx->wait);
		err = crypto_wait_req(ctx->enc ?
			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
						 &ctx->wait);

		if (!err)
			err = algif_skcipher_export(
				sk, &areq->cra_u.skcipher_req);
	}

free:
	af_alg_free_resources(areq);

	return err ? err : len;
}

static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
			    size_t ignored, int flags)
{
	struct sock *sk = sock->sk;
	int ret = 0;

	lock_sock(sk);
	while (msg_data_left(msg)) {
		int err = _skcipher_recvmsg(sock, msg, ignored, flags);

		/*
		 * This error covers -EIOCBQUEUED which implies that we can
		 * only handle one AIO request. If the caller wants to have
		 * multiple AIO requests in parallel, he must make multiple
		 * separate AIO calls.
		 *
		 * Also return the error if no data has been processed so far.
		 */
		if (err <= 0) {
			if (err == -EIOCBQUEUED || !ret)
				ret = err;
			goto out;
		}

		ret += err;
	}

out:
	af_alg_wmem_wakeup(sk);
	release_sock(sk);
	return ret;
}

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,
	.mmap		=	sock_no_mmap,
	.bind		=	sock_no_bind,
	.accept		=	sock_no_accept,

	.release	=	af_alg_release,
	.sendmsg	=	skcipher_sendmsg,
	.recvmsg	=	skcipher_recvmsg,
	.poll		=	af_alg_poll,
};

static int skcipher_check_key(struct socket *sock)
{
	int err = 0;
	struct sock *psk;
	struct alg_sock *pask;
	struct crypto_skcipher *tfm;
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);

	lock_sock(sk);
	if (!atomic_read(&ask->nokey_refcnt))
		goto unlock_child;

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

	err = -ENOKEY;
	lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
		goto unlock;

	atomic_dec(&pask->nokey_refcnt);
	atomic_set(&ask->nokey_refcnt, 0);

	err = 0;

unlock:
	release_sock(psk);
unlock_child:
	release_sock(sk);

	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 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,
	.mmap		=	sock_no_mmap,
	.bind		=	sock_no_bind,
	.accept		=	sock_no_accept,

	.release	=	af_alg_release,
	.sendmsg	=	skcipher_sendmsg_nokey,
	.recvmsg	=	skcipher_recvmsg_nokey,
	.poll		=	af_alg_poll,
};

static void *skcipher_bind(const char *name, u32 type, u32 mask)
{
	return crypto_alloc_skcipher(name, type, mask);
}

static void skcipher_release(void *private)
{
	crypto_free_skcipher(private);
}

static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
{
	return crypto_skcipher_setkey(private, key, keylen);
}

static void skcipher_sock_destruct(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct af_alg_ctx *ctx = ask->private;
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
	struct crypto_skcipher *tfm = pask->private;

	af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
	sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
	if (ctx->state)
		sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));
	sock_kfree_s(sk, ctx, ctx->len);
	af_alg_release_parent(sk);
}

static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
{
	struct af_alg_ctx *ctx;
	struct alg_sock *ask = alg_sk(sk);
	struct crypto_skcipher *tfm = private;
	unsigned int len = sizeof(*ctx);

	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;
	memset(ctx, 0, len);

	ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm),
			       GFP_KERNEL);
	if (!ctx->iv) {
		sock_kfree_s(sk, ctx, len);
		return -ENOMEM;
	}
	memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm));

	INIT_LIST_HEAD(&ctx->tsgl_list);
	ctx->len = len;
	crypto_init_wait(&ctx->wait);

	ask->private = ctx;

	sk->sk_destruct = skcipher_sock_destruct;

	return 0;
}

static int skcipher_accept_parent(void *private, struct sock *sk)
{
	struct crypto_skcipher *tfm = private;

	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
		return -ENOKEY;

	return skcipher_accept_parent_nokey(private, sk);
}

static const struct af_alg_type algif_type_skcipher = {
	.bind		=	skcipher_bind,
	.release	=	skcipher_release,
	.setkey		=	skcipher_setkey,
	.accept		=	skcipher_accept_parent,
	.accept_nokey	=	skcipher_accept_parent_nokey,
	.ops		=	&algif_skcipher_ops,
	.ops_nokey	=	&algif_skcipher_ops_nokey,
	.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_DESCRIPTION("Userspace interface for skcipher algorithms");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* algif_skcipher: User-space interface for skcipher algorithms
	4	*
	5	* This file provides the user-space API for symmetric key ciphers.
	6	*
	7	* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
	8	*
	9	* The following concept of the memory management is used:
	10	*
	11	* The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
	12	* filled by user space with the data submitted via sendmsg. Filling up the TX
	13	* SGL does not cause a crypto operation -- the data will only be tracked by
	14	* the kernel. Upon receipt of one recvmsg call, the caller must provide a
	15	* buffer which is tracked with the RX SGL.
	16	*
	17	* During the processing of the recvmsg operation, the cipher request is
	18	* allocated and prepared. As part of the recvmsg operation, the processed
	19	* TX buffers are extracted from the TX SGL into a separate SGL.
	20	*
	21	* After the completion of the crypto operation, the RX SGL and the cipher
	22	* request is released. The extracted TX SGL parts are released together with
	23	* the RX SGL release.
	24	*/
	25
	26	#include <crypto/scatterwalk.h>
	27	#include <crypto/skcipher.h>
	28	#include <crypto/if_alg.h>
	29	#include <linux/init.h>
	30	#include <linux/list.h>
	31	#include <linux/kernel.h>
	32	#include <linux/mm.h>
	33	#include <linux/module.h>
	34	#include <linux/net.h>
	35	#include <net/sock.h>
	36
	37	static int skcipher_sendmsg(struct socket sock, struct msghdr msg,
	38	size_t size)
	39	{
	40	struct sock *sk = sock->sk;
	41	struct alg_sock *ask = alg_sk(sk);
	42	struct sock *psk = ask->parent;
	43	struct alg_sock *pask = alg_sk(psk);
	44	struct crypto_skcipher *tfm = pask->private;
	45	unsigned ivsize = crypto_skcipher_ivsize(tfm);
	46
	47	return af_alg_sendmsg(sock, msg, size, ivsize);
	48	}
	49
	50	static int algif_skcipher_export(struct sock sk, struct skcipher_request req)
	51	{
	52	struct alg_sock *ask = alg_sk(sk);
	53	struct crypto_skcipher *tfm;
	54	struct af_alg_ctx *ctx;
	55	struct alg_sock *pask;
	56	unsigned statesize;
	57	struct sock *psk;
	58	int err;
	59
	60	if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL))
	61	return 0;
	62
	63	ctx = ask->private;
	64	psk = ask->parent;
	65	pask = alg_sk(psk);
	66	tfm = pask->private;
	67
	68	statesize = crypto_skcipher_statesize(tfm);
	69	ctx->state = sock_kmalloc(sk, statesize, GFP_ATOMIC);
	70	if (!ctx->state)
	71	return -ENOMEM;
	72
	73	err = crypto_skcipher_export(req, ctx->state);
	74	if (err) {
	75	sock_kzfree_s(sk, ctx->state, statesize);
	76	ctx->state = NULL;
	77	}
	78
	79	return err;
	80	}
	81
	82	static void algif_skcipher_done(void *data, int err)
	83	{
	84	struct af_alg_async_req *areq = data;
	85	struct sock *sk = areq->sk;
	86
	87	if (err)
	88	goto out;
	89
	90	err = algif_skcipher_export(sk, &areq->cra_u.skcipher_req);
	91
	92	out:
	93	af_alg_async_cb(data, err);
	94	}
	95
	96	static int _skcipher_recvmsg(struct socket sock, struct msghdr msg,
	97	size_t ignored, int flags)
	98	{
	99	struct sock *sk = sock->sk;
	100	struct alg_sock *ask = alg_sk(sk);
	101	struct sock *psk = ask->parent;
	102	struct alg_sock *pask = alg_sk(psk);
	103	struct af_alg_ctx *ctx = ask->private;
	104	struct crypto_skcipher *tfm = pask->private;
	105	unsigned int bs = crypto_skcipher_chunksize(tfm);
	106	struct af_alg_async_req *areq;
	107	unsigned cflags = 0;
	108	int err = 0;
	109	size_t len = 0;
	110
	111	if (!ctx->init \|\| (ctx->more && ctx->used < bs)) {
	112	err = af_alg_wait_for_data(sk, flags, bs);
	113	if (err)
	114	return err;
	115	}
	116
	117	/* Allocate cipher request for current operation. */
	118	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
	119	crypto_skcipher_reqsize(tfm));
	120	if (IS_ERR(areq))
	121	return PTR_ERR(areq);
	122
	123	/* convert iovecs of output buffers into RX SGL */
	124	err = af_alg_get_rsgl(sk, msg, flags, areq, ctx->used, &len);
	125	if (err)
	126	goto free;
	127
	128	/*
	129	* If more buffers are to be expected to be processed, process only
	130	* full block size buffers.
	131	*/
	132	if (ctx->more \|\| len < ctx->used) {
	133	len -= len % bs;
	134	cflags \|= CRYPTO_SKCIPHER_REQ_NOTFINAL;
	135	}
	136
	137	/*
	138	* Create a per request TX SGL for this request which tracks the
	139	* SG entries from the global TX SGL.
	140	*/
	141	areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
	142	if (!areq->tsgl_entries)
	143	areq->tsgl_entries = 1;
	144	areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
	145	areq->tsgl_entries),
	146	GFP_KERNEL);
	147	if (!areq->tsgl) {
	148	err = -ENOMEM;
	149	goto free;
	150	}
	151	sg_init_table(areq->tsgl, areq->tsgl_entries);
	152	af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
	153
	154	/* Initialize the crypto operation */
	155	skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
	156	skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
	157	areq->first_rsgl.sgl.sgt.sgl, len, ctx->iv);
	158
	159	if (ctx->state) {
	160	err = crypto_skcipher_import(&areq->cra_u.skcipher_req,
	161	ctx->state);
	162	sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));
	163	ctx->state = NULL;
	164	if (err)
	165	goto free;
	166	cflags \|= CRYPTO_SKCIPHER_REQ_CONT;
	167	}
	168
	169	if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
	170	/* AIO operation */
	171	sock_hold(sk);
	172	areq->iocb = msg->msg_iocb;
	173
	174	/* Remember output size that will be generated. */
	175	areq->outlen = len;
	176
	177	skcipher_request_set_callback(&areq->cra_u.skcipher_req,
	178	cflags \|
	179	CRYPTO_TFM_REQ_MAY_SLEEP,
	180	algif_skcipher_done, areq);
	181	err = ctx->enc ?
	182	crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
	183	crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
	184
	185	/* AIO operation in progress */
	186	if (err == -EINPROGRESS)
	187	return -EIOCBQUEUED;
	188
	189	sock_put(sk);
	190	} else {
	191	/* Synchronous operation */
	192	skcipher_request_set_callback(&areq->cra_u.skcipher_req,
	193	cflags \|
	194	CRYPTO_TFM_REQ_MAY_SLEEP \|
	195	CRYPTO_TFM_REQ_MAY_BACKLOG,
	196	crypto_req_done, &ctx->wait);
	197	err = crypto_wait_req(ctx->enc ?
	198	crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
	199	crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
	200	&ctx->wait);
	201
	202	if (!err)
	203	err = algif_skcipher_export(
	204	sk, &areq->cra_u.skcipher_req);
	205	}
	206
	207	free:
	208	af_alg_free_resources(areq);
	209
	210	return err ? err : len;
	211	}
	212
	213	static int skcipher_recvmsg(struct socket sock, struct msghdr msg,
	214	size_t ignored, int flags)
	215	{
	216	struct sock *sk = sock->sk;
	217	int ret = 0;
	218
	219	lock_sock(sk);
	220	while (msg_data_left(msg)) {
	221	int err = _skcipher_recvmsg(sock, msg, ignored, flags);
	222
	223	/*
	224	* This error covers -EIOCBQUEUED which implies that we can
	225	* only handle one AIO request. If the caller wants to have
	226	* multiple AIO requests in parallel, he must make multiple
	227	* separate AIO calls.
	228	*
	229	* Also return the error if no data has been processed so far.
	230	*/
	231	if (err <= 0) {
	232	if (err == -EIOCBQUEUED \|\| !ret)
	233	ret = err;
	234	goto out;
	235	}
	236
	237	ret += err;
	238	}
	239
	240	out:
	241	af_alg_wmem_wakeup(sk);
	242	release_sock(sk);
	243	return ret;
	244	}
	245
	246	static struct proto_ops algif_skcipher_ops = {
	247	.family = PF_ALG,
	248
	249	.connect = sock_no_connect,
	250	.socketpair = sock_no_socketpair,
	251	.getname = sock_no_getname,
	252	.ioctl = sock_no_ioctl,
	253	.listen = sock_no_listen,
	254	.shutdown = sock_no_shutdown,
	255	.mmap = sock_no_mmap,
	256	.bind = sock_no_bind,
	257	.accept = sock_no_accept,
	258
	259	.release = af_alg_release,
	260	.sendmsg = skcipher_sendmsg,
	261	.recvmsg = skcipher_recvmsg,
	262	.poll = af_alg_poll,
	263	};
	264
	265	static int skcipher_check_key(struct socket *sock)
	266	{
	267	int err = 0;
	268	struct sock *psk;
	269	struct alg_sock *pask;
	270	struct crypto_skcipher *tfm;
	271	struct sock *sk = sock->sk;
	272	struct alg_sock *ask = alg_sk(sk);
	273
	274	lock_sock(sk);
	275	if (!atomic_read(&ask->nokey_refcnt))
	276	goto unlock_child;
	277
	278	psk = ask->parent;
	279	pask = alg_sk(ask->parent);
	280	tfm = pask->private;
	281
	282	err = -ENOKEY;
	283	lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
	284	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
	285	goto unlock;
	286
	287	atomic_dec(&pask->nokey_refcnt);
	288	atomic_set(&ask->nokey_refcnt, 0);
	289
	290	err = 0;
	291
	292	unlock:
	293	release_sock(psk);
	294	unlock_child:
	295	release_sock(sk);
	296
	297	return err;
	298	}
	299
	300	static int skcipher_sendmsg_nokey(struct socket sock, struct msghdr msg,
	301	size_t size)
	302	{
	303	int err;
	304
	305	err = skcipher_check_key(sock);
	306	if (err)
	307	return err;
	308
	309	return skcipher_sendmsg(sock, msg, size);
	310	}
	311
	312	static int skcipher_recvmsg_nokey(struct socket sock, struct msghdr msg,
	313	size_t ignored, int flags)
	314	{
	315	int err;
	316
	317	err = skcipher_check_key(sock);
	318	if (err)
	319	return err;
	320
	321	return skcipher_recvmsg(sock, msg, ignored, flags);
	322	}
	323
	324	static struct proto_ops algif_skcipher_ops_nokey = {
	325	.family = PF_ALG,
	326
	327	.connect = sock_no_connect,
	328	.socketpair = sock_no_socketpair,
	329	.getname = sock_no_getname,
	330	.ioctl = sock_no_ioctl,
	331	.listen = sock_no_listen,
	332	.shutdown = sock_no_shutdown,
	333	.mmap = sock_no_mmap,
	334	.bind = sock_no_bind,
	335	.accept = sock_no_accept,
	336
	337	.release = af_alg_release,
	338	.sendmsg = skcipher_sendmsg_nokey,
	339	.recvmsg = skcipher_recvmsg_nokey,
	340	.poll = af_alg_poll,
	341	};
	342
	343	static void skcipher_bind(const char name, u32 type, u32 mask)
	344	{
	345	return crypto_alloc_skcipher(name, type, mask);
	346	}
	347
	348	static void skcipher_release(void *private)
	349	{
	350	crypto_free_skcipher(private);
	351	}
	352
	353	static int skcipher_setkey(void private, const u8 key, unsigned int keylen)
	354	{
	355	return crypto_skcipher_setkey(private, key, keylen);
	356	}
	357
	358	static void skcipher_sock_destruct(struct sock *sk)
	359	{
	360	struct alg_sock *ask = alg_sk(sk);
	361	struct af_alg_ctx *ctx = ask->private;
	362	struct sock *psk = ask->parent;
	363	struct alg_sock *pask = alg_sk(psk);
	364	struct crypto_skcipher *tfm = pask->private;
	365
	366	af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
	367	sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
	368	if (ctx->state)
	369	sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));
	370	sock_kfree_s(sk, ctx, ctx->len);
	371	af_alg_release_parent(sk);
	372	}
	373
	374	static int skcipher_accept_parent_nokey(void private, struct sock sk)
	375	{
	376	struct af_alg_ctx *ctx;
	377	struct alg_sock *ask = alg_sk(sk);
	378	struct crypto_skcipher *tfm = private;
	379	unsigned int len = sizeof(*ctx);
	380
	381	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
	382	if (!ctx)
	383	return -ENOMEM;
	384	memset(ctx, 0, len);
	385
	386	ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm),
	387	GFP_KERNEL);
	388	if (!ctx->iv) {
	389	sock_kfree_s(sk, ctx, len);
	390	return -ENOMEM;
	391	}
	392	memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm));
	393
	394	INIT_LIST_HEAD(&ctx->tsgl_list);
	395	ctx->len = len;
	396	crypto_init_wait(&ctx->wait);
	397
	398	ask->private = ctx;
	399
	400	sk->sk_destruct = skcipher_sock_destruct;
	401
	402	return 0;
	403	}
	404
	405	static int skcipher_accept_parent(void private, struct sock sk)
	406	{
	407	struct crypto_skcipher *tfm = private;
	408
	409	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
	410	return -ENOKEY;
	411
	412	return skcipher_accept_parent_nokey(private, sk);
	413	}
	414
	415	static const struct af_alg_type algif_type_skcipher = {
	416	.bind = skcipher_bind,
	417	.release = skcipher_release,
	418	.setkey = skcipher_setkey,
	419	.accept = skcipher_accept_parent,
	420	.accept_nokey = skcipher_accept_parent_nokey,
	421	.ops = &algif_skcipher_ops,
	422	.ops_nokey = &algif_skcipher_ops_nokey,
	423	.name = "skcipher",
	424	.owner = THIS_MODULE
	425	};
	426
	427	static int __init algif_skcipher_init(void)
	428	{
	429	return af_alg_register_type(&algif_type_skcipher);
	430	}
	431
	432	static void __exit algif_skcipher_exit(void)
	433	{
	434	int err = af_alg_unregister_type(&algif_type_skcipher);
	435	BUG_ON(err);
	436	}
	437
	438	module_init(algif_skcipher_init);
	439	module_exit(algif_skcipher_exit);
	440	MODULE_DESCRIPTION("Userspace interface for skcipher algorithms");
	441	MODULE_LICENSE("GPL");