crypto/algif_skcipher.c - linux - Git at Google

 // 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_LICENSE("GPL");
	// 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_LICENSE("GPL");