crypto/algif_aead.c - kernel/msm-4.19 - Gitiles

 /*
  * algif_aead: User-space interface for AEAD algorithms
  *
  * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>
  *
  * This file provides the user-space API for AEAD ciphers.
  *
  * This file is derived from algif_skcipher.c.
  *
  * 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/internal/aead.h>
 #include <crypto/scatterwalk.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>

 struct aead_sg_list {
 	unsigned int cur;
 	struct scatterlist sg[ALG_MAX_PAGES];
 };

 struct aead_async_rsgl {
 	struct af_alg_sgl sgl;
 	struct list_head list;
 };

 struct aead_async_req {
 	struct scatterlist *tsgl;
 	struct aead_async_rsgl first_rsgl;
 	struct list_head list;
 	struct kiocb *iocb;
 	unsigned int tsgls;
 	char iv[];
 };

 struct aead_ctx {
 	struct aead_sg_list tsgl;
 	struct aead_async_rsgl first_rsgl;
 	struct list_head list;

 	void *iv;

 	struct af_alg_completion completion;

 	unsigned long used;

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

 	size_t aead_assoclen;
 	struct aead_request aead_req;
 };

 static inline int aead_sndbuf(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;

 	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
 			  ctx->used, 0);
 }

 static inline bool aead_writable(struct sock *sk)
 {
 	return PAGE_SIZE <= aead_sndbuf(sk);
 }

 static inline bool aead_sufficient_data(struct aead_ctx *ctx)
 {
 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));

 	return ctx->used >= ctx->aead_assoclen + as;
 }

 static void aead_reset_ctx(struct aead_ctx *ctx)
 {
 	struct aead_sg_list *sgl = &ctx->tsgl;

 	sg_init_table(sgl->sg, ALG_MAX_PAGES);
 	sgl->cur = 0;
 	ctx->used = 0;
 	ctx->more = 0;
 	ctx->merge = 0;
 }

 static void aead_put_sgl(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	struct aead_sg_list *sgl = &ctx->tsgl;
 	struct scatterlist *sg = sgl->sg;
 	unsigned int i;

 	for (i = 0; i < sgl->cur; i++) {
 		if (!sg_page(sg + i))
 			continue;

 		put_page(sg_page(sg + i));
 		sg_assign_page(sg + i, NULL);
 	}
 	aead_reset_ctx(ctx);
 }

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

 	if (!aead_writable(sk))
 		return;

 	rcu_read_lock();
 	wq = rcu_dereference(sk->sk_wq);
 	if (skwq_has_sleeper(wq))
 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 							   POLLRDNORM |
 							   POLLRDBAND);
 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 	rcu_read_unlock();
 }

 static int aead_wait_for_data(struct sock *sk, unsigned flags)
 {
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	long timeout;
 	int err = -ERESTARTSYS;

 	if (flags & MSG_DONTWAIT)
 		return -EAGAIN;

 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 	add_wait_queue(sk_sleep(sk), &wait);
 	for (;;) {
 		if (signal_pending(current))
 			break;
 		timeout = MAX_SCHEDULE_TIMEOUT;
 		if (sk_wait_event(sk, &timeout, !ctx->more, &wait)) {
 			err = 0;
 			break;
 		}
 	}
 	remove_wait_queue(sk_sleep(sk), &wait);

 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);

 	return err;
 }

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

 	if (ctx->more)
 		return;
 	if (!ctx->used)
 		return;

 	rcu_read_lock();
 	wq = rcu_dereference(sk->sk_wq);
 	if (skwq_has_sleeper(wq))
 		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 							   POLLRDNORM |
 							   POLLRDBAND);
 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 	rcu_read_unlock();
 }

 static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	unsigned ivsize =
 		crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
 	struct aead_sg_list *sgl = &ctx->tsgl;
 	struct af_alg_control con = {};
 	long copied = 0;
 	bool enc = 0;
 	bool init = 0;
 	int err = -EINVAL;

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

 		init = 1;
 		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;
 	}

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

 	if (init) {
 		ctx->enc = enc;
 		if (con.iv)
 			memcpy(ctx->iv, con.iv->iv, ivsize);

 		ctx->aead_assoclen = con.aead_assoclen;
 	}

 	while (size) {
 		size_t len = size;
 		struct scatterlist *sg = NULL;

 		/* use the existing memory in an allocated page */
 		if (ctx->merge) {
 			sg = sgl->sg + sgl->cur - 1;
 			len = min_t(unsigned long, len,
 				    PAGE_SIZE - sg->offset - sg->length);
 			err = memcpy_from_msg(page_address(sg_page(sg)) +
 					      sg->offset + sg->length,
 					      msg, len);
 			if (err)
 				goto unlock;

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

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

 		if (!aead_writable(sk)) {
 			/* user space sent too much data */
 			aead_put_sgl(sk);
 			err = -EMSGSIZE;
 			goto unlock;
 		}

 		/* allocate a new page */
 		len = min_t(unsigned long, size, aead_sndbuf(sk));
 		while (len) {
 			size_t plen = 0;

 			if (sgl->cur >= ALG_MAX_PAGES) {
 				aead_put_sgl(sk);
 				err = -E2BIG;
 				goto unlock;
 			}

 			sg = sgl->sg + sgl->cur;
 			plen = min_t(size_t, len, PAGE_SIZE);

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

 			err = memcpy_from_msg(page_address(sg_page(sg)),
 					      msg, plen);
 			if (err) {
 				__free_page(sg_page(sg));
 				sg_assign_page(sg, NULL);
 				goto unlock;
 			}

 			sg->offset = 0;
 			sg->length = plen;
 			len -= plen;
 			ctx->used += plen;
 			copied += plen;
 			sgl->cur++;
 			size -= plen;
 			ctx->merge = plen & (PAGE_SIZE - 1);
 		}
 	}

 	err = 0;

 	ctx->more = msg->msg_flags & MSG_MORE;
 	if (!ctx->more && !aead_sufficient_data(ctx)) {
 		aead_put_sgl(sk);
 		err = -EMSGSIZE;
 	}

 unlock:
 	aead_data_wakeup(sk);
 	release_sock(sk);

 	return err ?: copied;
 }

 static ssize_t aead_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 aead_ctx *ctx = ask->private;
 	struct aead_sg_list *sgl = &ctx->tsgl;
 	int err = -EINVAL;

 	if (flags & MSG_SENDPAGE_NOTLAST)
 		flags |= MSG_MORE;

 	if (sgl->cur >= ALG_MAX_PAGES)
 		return -E2BIG;

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

 	if (!size)
 		goto done;

 	if (!aead_writable(sk)) {
 		/* user space sent too much data */
 		aead_put_sgl(sk);
 		err = -EMSGSIZE;
 		goto unlock;
 	}

 	ctx->merge = 0;

 	get_page(page);
 	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 	sgl->cur++;
 	ctx->used += size;

 	err = 0;

 done:
 	ctx->more = flags & MSG_MORE;
 	if (!ctx->more && !aead_sufficient_data(ctx)) {
 		aead_put_sgl(sk);
 		err = -EMSGSIZE;
 	}

 unlock:
 	aead_data_wakeup(sk);
 	release_sock(sk);

 	return err ?: size;
 }

 #define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \
 		((char *)req + sizeof(struct aead_request) + \
 		 crypto_aead_reqsize(tfm))

  #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \
 	crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \
 	sizeof(struct aead_request)

 static void aead_async_cb(struct crypto_async_request *_req, int err)
 {
 	struct sock *sk = _req->data;
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
 	struct aead_request *req = aead_request_cast(_req);
 	struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);
 	struct scatterlist *sg = areq->tsgl;
 	struct aead_async_rsgl *rsgl;
 	struct kiocb *iocb = areq->iocb;
 	unsigned int i, reqlen = GET_REQ_SIZE(tfm);

 	list_for_each_entry(rsgl, &areq->list, list) {
 		af_alg_free_sg(&rsgl->sgl);
 		if (rsgl != &areq->first_rsgl)
 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 	}

 	for (i = 0; i < areq->tsgls; i++)
 		put_page(sg_page(sg + i));

 	sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
 	sock_kfree_s(sk, req, reqlen);
 	__sock_put(sk);
 	iocb->ki_complete(iocb, err, err);
 }

 static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg,
 			      int flags)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
 	struct aead_async_req *areq;
 	struct aead_request *req = NULL;
 	struct aead_sg_list *sgl = &ctx->tsgl;
 	struct aead_async_rsgl *last_rsgl = NULL, *rsgl;
 	unsigned int as = crypto_aead_authsize(tfm);
 	unsigned int i, reqlen = GET_REQ_SIZE(tfm);
 	int err = -ENOMEM;
 	unsigned long used;
 	size_t outlen;
 	size_t usedpages = 0;

 	lock_sock(sk);
 	if (ctx->more) {
 		err = aead_wait_for_data(sk, flags);
 		if (err)
 			goto unlock;
 	}

 	used = ctx->used;
 	outlen = used;

 	if (!aead_sufficient_data(ctx))
 		goto unlock;

 	req = sock_kmalloc(sk, reqlen, GFP_KERNEL);
 	if (unlikely(!req))
 		goto unlock;

 	areq = GET_ASYM_REQ(req, tfm);
 	memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));
 	INIT_LIST_HEAD(&areq->list);
 	areq->iocb = msg->msg_iocb;
 	memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));
 	aead_request_set_tfm(req, tfm);
 	aead_request_set_ad(req, ctx->aead_assoclen);
 	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 				  aead_async_cb, sk);
 	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);

 	/* take over all tx sgls from ctx */
 	areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * sgl->cur,
 				  GFP_KERNEL);
 	if (unlikely(!areq->tsgl))
 		goto free;

 	sg_init_table(areq->tsgl, sgl->cur);
 	for (i = 0; i < sgl->cur; i++)
 		sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]),
 			    sgl->sg[i].length, sgl->sg[i].offset);

 	areq->tsgls = sgl->cur;

 	/* create rx sgls */
 	while (iov_iter_count(&msg->msg_iter)) {
 		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
 				      (outlen - usedpages));

 		if (list_empty(&areq->list)) {
 			rsgl = &areq->first_rsgl;

 		} else {
 			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
 			if (unlikely(!rsgl)) {
 				err = -ENOMEM;
 				goto free;
 			}
 		}
 		rsgl->sgl.npages = 0;
 		list_add_tail(&rsgl->list, &areq->list);

 		/* make one iovec available as scatterlist */
 		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
 		if (err < 0)
 			goto free;

 		usedpages += err;

 		/* chain the new scatterlist with previous one */
 		if (last_rsgl)
 			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);

 		last_rsgl = rsgl;

 		/* we do not need more iovecs as we have sufficient memory */
 		if (outlen <= usedpages)
 			break;

 		iov_iter_advance(&msg->msg_iter, err);
 	}
 	err = -EINVAL;
 	/* ensure output buffer is sufficiently large */
 	if (usedpages < outlen)
 		goto free;

 	aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used,
 			       areq->iv);
 	err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
 	if (err) {
 		if (err == -EINPROGRESS) {
 			sock_hold(sk);
 			err = -EIOCBQUEUED;
 			aead_reset_ctx(ctx);
 			goto unlock;
 		} else if (err == -EBADMSG) {
 			aead_put_sgl(sk);
 		}
 		goto free;
 	}
 	aead_put_sgl(sk);

 free:
 	list_for_each_entry(rsgl, &areq->list, list) {
 		af_alg_free_sg(&rsgl->sgl);
 		if (rsgl != &areq->first_rsgl)
 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 	}
 	if (areq->tsgl)
 		sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
 	if (req)
 		sock_kfree_s(sk, req, reqlen);
 unlock:
 	aead_wmem_wakeup(sk);
 	release_sock(sk);
 	return err ? err : outlen;
 }

 static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
 	struct aead_sg_list *sgl = &ctx->tsgl;
 	struct aead_async_rsgl *last_rsgl = NULL;
 	struct aead_async_rsgl *rsgl, *tmp;
 	int err = -EINVAL;
 	unsigned long used = 0;
 	size_t outlen = 0;
 	size_t usedpages = 0;

 	lock_sock(sk);

 	/*
 	 * AEAD memory structure: For encryption, the tag is appended to the
 	 * ciphertext which implies that the memory allocated for the ciphertext
 	 * must be increased by the tag length. For decryption, the tag
 	 * is expected to be concatenated to the ciphertext. The plaintext
 	 * therefore has a memory size of the ciphertext minus the tag length.
 	 *
 	 * The memory structure for cipher operation has the following
 	 * structure:
 	 *	AEAD encryption input:  assoc data || plaintext
 	 *	AEAD encryption output: cipherntext || auth tag
 	 *	AEAD decryption input:  assoc data || ciphertext || auth tag
 	 *	AEAD decryption output: plaintext
 	 */

 	if (ctx->more) {
 		err = aead_wait_for_data(sk, flags);
 		if (err)
 			goto unlock;
 	}

 	used = ctx->used;

 	/*
 	 * Make sure sufficient data is present -- note, the same check is
 	 * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
 	 * shall provide an information to the data sender that something is
 	 * wrong, but they are irrelevant to maintain the kernel integrity.
 	 * We need this check here too in case user space decides to not honor
 	 * the error message in sendmsg/sendpage and still call recvmsg. This
 	 * check here protects the kernel integrity.
 	 */
 	if (!aead_sufficient_data(ctx))
 		goto unlock;

 	outlen = used;

 	/*
 	 * The cipher operation input data is reduced by the associated data
 	 * length as this data is processed separately later on.
 	 */
 	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);

 	/* convert iovecs of output buffers into scatterlists */
 	while (iov_iter_count(&msg->msg_iter)) {
 		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
 				      (outlen - usedpages));

 		if (list_empty(&ctx->list)) {
 			rsgl = &ctx->first_rsgl;
 		} else {
 			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
 			if (unlikely(!rsgl)) {
 				err = -ENOMEM;
 				goto unlock;
 			}
 		}
 		rsgl->sgl.npages = 0;
 		list_add_tail(&rsgl->list, &ctx->list);

 		/* make one iovec available as scatterlist */
 		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
 		if (err < 0)
 			goto unlock;
 		usedpages += err;
 		/* chain the new scatterlist with previous one */
 		if (last_rsgl)
 			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);

 		last_rsgl = rsgl;

 		/* we do not need more iovecs as we have sufficient memory */
 		if (outlen <= usedpages)
 			break;
 		iov_iter_advance(&msg->msg_iter, err);
 	}

 	err = -EINVAL;
 	/* ensure output buffer is sufficiently large */
 	if (usedpages < outlen)
 		goto unlock;

 	sg_mark_end(sgl->sg + sgl->cur - 1);
 	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
 			       used, ctx->iv);
 	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);

 	err = af_alg_wait_for_completion(ctx->enc ?
 					 crypto_aead_encrypt(&ctx->aead_req) :
 					 crypto_aead_decrypt(&ctx->aead_req),
 					 &ctx->completion);

 	if (err) {
 		/* EBADMSG implies a valid cipher operation took place */
 		if (err == -EBADMSG)
 			aead_put_sgl(sk);

 		goto unlock;
 	}

 	aead_put_sgl(sk);
 	err = 0;

 unlock:
 	list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) {
 		af_alg_free_sg(&rsgl->sgl);
 		if (rsgl != &ctx->first_rsgl)
 			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 		list_del(&rsgl->list);
 	}
 	INIT_LIST_HEAD(&ctx->list);
 	aead_wmem_wakeup(sk);
 	release_sock(sk);

 	return err ? err : outlen;
 }

 static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
 			int flags)
 {
 	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
 		aead_recvmsg_async(sock, msg, flags) :
 		aead_recvmsg_sync(sock, msg, flags);
 }

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

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

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

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

 	return mask;
 }

 static struct proto_ops algif_aead_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	=	aead_sendmsg,
 	.sendpage	=	aead_sendpage,
 	.recvmsg	=	aead_recvmsg,
 	.poll		=	aead_poll,
 };

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

 static void aead_release(void *private)
 {
 	crypto_free_aead(private);
 }

 static int aead_setauthsize(void *private, unsigned int authsize)
 {
 	return crypto_aead_setauthsize(private, authsize);
 }

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

 static void aead_sock_destruct(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	struct aead_ctx *ctx = ask->private;
 	unsigned int ivlen = crypto_aead_ivsize(
 				crypto_aead_reqtfm(&ctx->aead_req));

 	WARN_ON(atomic_read(&sk->sk_refcnt) != 0);
 	aead_put_sgl(sk);
 	sock_kzfree_s(sk, ctx->iv, ivlen);
 	sock_kfree_s(sk, ctx, ctx->len);
 	af_alg_release_parent(sk);
 }

 static int aead_accept_parent(void *private, struct sock *sk)
 {
 	struct aead_ctx *ctx;
 	struct alg_sock *ask = alg_sk(sk);
 	unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private);
 	unsigned int ivlen = crypto_aead_ivsize(private);

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

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

 	ctx->len = len;
 	ctx->used = 0;
 	ctx->more = 0;
 	ctx->merge = 0;
 	ctx->enc = 0;
 	ctx->tsgl.cur = 0;
 	ctx->aead_assoclen = 0;
 	af_alg_init_completion(&ctx->completion);
 	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
 	INIT_LIST_HEAD(&ctx->list);

 	ask->private = ctx;

 	aead_request_set_tfm(&ctx->aead_req, private);
 	aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 				  af_alg_complete, &ctx->completion);

 	sk->sk_destruct = aead_sock_destruct;

 	return 0;
 }

 static const struct af_alg_type algif_type_aead = {
 	.bind		=	aead_bind,
 	.release	=	aead_release,
 	.setkey		=	aead_setkey,
 	.setauthsize	=	aead_setauthsize,
 	.accept		=	aead_accept_parent,
 	.ops		=	&algif_aead_ops,
 	.name		=	"aead",
 	.owner		=	THIS_MODULE
 };

 static int __init algif_aead_init(void)
 {
 	return af_alg_register_type(&algif_type_aead);
 }

 static void __exit algif_aead_exit(void)
 {
 	int err = af_alg_unregister_type(&algif_type_aead);
 	BUG_ON(err);
 }

 module_init(algif_aead_init);
 module_exit(algif_aead_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
 MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");
	/*
	* algif_aead: User-space interface for AEAD algorithms
	*
	* Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>
	*
	* This file provides the user-space API for AEAD ciphers.
	*
	* This file is derived from algif_skcipher.c.
	*
	* 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/internal/aead.h>
	#include <crypto/scatterwalk.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>

	struct aead_sg_list {
	unsigned int cur;
	struct scatterlist sg[ALG_MAX_PAGES];
	};

	struct aead_async_rsgl {
	struct af_alg_sgl sgl;
	struct list_head list;
	};

	struct aead_async_req {
	struct scatterlist *tsgl;
	struct aead_async_rsgl first_rsgl;
	struct list_head list;
	struct kiocb *iocb;
	unsigned int tsgls;
	char iv[];
	};

	struct aead_ctx {
	struct aead_sg_list tsgl;
	struct aead_async_rsgl first_rsgl;
	struct list_head list;

	void *iv;

	struct af_alg_completion completion;

	unsigned long used;

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

	size_t aead_assoclen;
	struct aead_request aead_req;
	};

	static inline int aead_sndbuf(struct sock *sk)
	{
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;

	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
	ctx->used, 0);
	}

	static inline bool aead_writable(struct sock *sk)
	{
	return PAGE_SIZE <= aead_sndbuf(sk);
	}

	static inline bool aead_sufficient_data(struct aead_ctx *ctx)
	{
	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));

	return ctx->used >= ctx->aead_assoclen + as;
	}

	static void aead_reset_ctx(struct aead_ctx *ctx)
	{
	struct aead_sg_list *sgl = &ctx->tsgl;

	sg_init_table(sgl->sg, ALG_MAX_PAGES);
	sgl->cur = 0;
	ctx->used = 0;
	ctx->more = 0;
	ctx->merge = 0;
	}

	static void aead_put_sgl(struct sock *sk)
	{
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	struct aead_sg_list *sgl = &ctx->tsgl;
	struct scatterlist *sg = sgl->sg;
	unsigned int i;

	for (i = 0; i < sgl->cur; i++) {
	if (!sg_page(sg + i))
	continue;

	put_page(sg_page(sg + i));
	sg_assign_page(sg + i, NULL);
	}
	aead_reset_ctx(ctx);
	}

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

	if (!aead_writable(sk))
	return;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
	if (skwq_has_sleeper(wq))
	wake_up_interruptible_sync_poll(&wq->wait, POLLIN \|
	POLLRDNORM \|
	POLLRDBAND);
	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
	rcu_read_unlock();
	}

	static int aead_wait_for_data(struct sock *sk, unsigned flags)
	{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	long timeout;
	int err = -ERESTARTSYS;

	if (flags & MSG_DONTWAIT)
	return -EAGAIN;

	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
	add_wait_queue(sk_sleep(sk), &wait);
	for (;;) {
	if (signal_pending(current))
	break;
	timeout = MAX_SCHEDULE_TIMEOUT;
	if (sk_wait_event(sk, &timeout, !ctx->more, &wait)) {
	err = 0;
	break;
	}
	}
	remove_wait_queue(sk_sleep(sk), &wait);

	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);

	return err;
	}

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

	if (ctx->more)
	return;
	if (!ctx->used)
	return;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
	if (skwq_has_sleeper(wq))
	wake_up_interruptible_sync_poll(&wq->wait, POLLOUT \|
	POLLRDNORM \|
	POLLRDBAND);
	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	rcu_read_unlock();
	}

	static int aead_sendmsg(struct socket sock, struct msghdr msg, size_t size)
	{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	unsigned ivsize =
	crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
	struct aead_sg_list *sgl = &ctx->tsgl;
	struct af_alg_control con = {};
	long copied = 0;
	bool enc = 0;
	bool init = 0;
	int err = -EINVAL;

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

	init = 1;
	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;
	}

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

	if (init) {
	ctx->enc = enc;
	if (con.iv)
	memcpy(ctx->iv, con.iv->iv, ivsize);

	ctx->aead_assoclen = con.aead_assoclen;
	}

	while (size) {
	size_t len = size;
	struct scatterlist *sg = NULL;

	/* use the existing memory in an allocated page */
	if (ctx->merge) {
	sg = sgl->sg + sgl->cur - 1;
	len = min_t(unsigned long, len,
	PAGE_SIZE - sg->offset - sg->length);
	err = memcpy_from_msg(page_address(sg_page(sg)) +
	sg->offset + sg->length,
	msg, len);
	if (err)
	goto unlock;

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

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

	if (!aead_writable(sk)) {
	/* user space sent too much data */
	aead_put_sgl(sk);
	err = -EMSGSIZE;
	goto unlock;
	}

	/* allocate a new page */
	len = min_t(unsigned long, size, aead_sndbuf(sk));
	while (len) {
	size_t plen = 0;

	if (sgl->cur >= ALG_MAX_PAGES) {
	aead_put_sgl(sk);
	err = -E2BIG;
	goto unlock;
	}

	sg = sgl->sg + sgl->cur;
	plen = min_t(size_t, len, PAGE_SIZE);

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

	err = memcpy_from_msg(page_address(sg_page(sg)),
	msg, plen);
	if (err) {
	__free_page(sg_page(sg));
	sg_assign_page(sg, NULL);
	goto unlock;
	}

	sg->offset = 0;
	sg->length = plen;
	len -= plen;
	ctx->used += plen;
	copied += plen;
	sgl->cur++;
	size -= plen;
	ctx->merge = plen & (PAGE_SIZE - 1);
	}
	}

	err = 0;

	ctx->more = msg->msg_flags & MSG_MORE;
	if (!ctx->more && !aead_sufficient_data(ctx)) {
	aead_put_sgl(sk);
	err = -EMSGSIZE;
	}

	unlock:
	aead_data_wakeup(sk);
	release_sock(sk);

	return err ?: copied;
	}

	static ssize_t aead_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 aead_ctx *ctx = ask->private;
	struct aead_sg_list *sgl = &ctx->tsgl;
	int err = -EINVAL;

	if (flags & MSG_SENDPAGE_NOTLAST)
	flags \|= MSG_MORE;

	if (sgl->cur >= ALG_MAX_PAGES)
	return -E2BIG;

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

	if (!size)
	goto done;

	if (!aead_writable(sk)) {
	/* user space sent too much data */
	aead_put_sgl(sk);
	err = -EMSGSIZE;
	goto unlock;
	}

	ctx->merge = 0;

	get_page(page);
	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
	sgl->cur++;
	ctx->used += size;

	err = 0;

	done:
	ctx->more = flags & MSG_MORE;
	if (!ctx->more && !aead_sufficient_data(ctx)) {
	aead_put_sgl(sk);
	err = -EMSGSIZE;
	}

	unlock:
	aead_data_wakeup(sk);
	release_sock(sk);

	return err ?: size;
	}

	#define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \
	((char *)req + sizeof(struct aead_request) + \
	crypto_aead_reqsize(tfm))

	#define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \
	crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \
	sizeof(struct aead_request)

	static void aead_async_cb(struct crypto_async_request *_req, int err)
	{
	struct sock *sk = _req->data;
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
	struct aead_request *req = aead_request_cast(_req);
	struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);
	struct scatterlist *sg = areq->tsgl;
	struct aead_async_rsgl *rsgl;
	struct kiocb *iocb = areq->iocb;
	unsigned int i, reqlen = GET_REQ_SIZE(tfm);

	list_for_each_entry(rsgl, &areq->list, list) {
	af_alg_free_sg(&rsgl->sgl);
	if (rsgl != &areq->first_rsgl)
	sock_kfree_s(sk, rsgl, sizeof(*rsgl));
	}

	for (i = 0; i < areq->tsgls; i++)
	put_page(sg_page(sg + i));

	sock_kfree_s(sk, areq->tsgl, sizeof(areq->tsgl) areq->tsgls);
	sock_kfree_s(sk, req, reqlen);
	__sock_put(sk);
	iocb->ki_complete(iocb, err, err);
	}

	static int aead_recvmsg_async(struct socket sock, struct msghdr msg,
	int flags)
	{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
	struct aead_async_req *areq;
	struct aead_request *req = NULL;
	struct aead_sg_list *sgl = &ctx->tsgl;
	struct aead_async_rsgl last_rsgl = NULL, rsgl;
	unsigned int as = crypto_aead_authsize(tfm);
	unsigned int i, reqlen = GET_REQ_SIZE(tfm);
	int err = -ENOMEM;
	unsigned long used;
	size_t outlen;
	size_t usedpages = 0;

	lock_sock(sk);
	if (ctx->more) {
	err = aead_wait_for_data(sk, flags);
	if (err)
	goto unlock;
	}

	used = ctx->used;
	outlen = used;

	if (!aead_sufficient_data(ctx))
	goto unlock;

	req = sock_kmalloc(sk, reqlen, GFP_KERNEL);
	if (unlikely(!req))
	goto unlock;

	areq = GET_ASYM_REQ(req, tfm);
	memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));
	INIT_LIST_HEAD(&areq->list);
	areq->iocb = msg->msg_iocb;
	memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));
	aead_request_set_tfm(req, tfm);
	aead_request_set_ad(req, ctx->aead_assoclen);
	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
	aead_async_cb, sk);
	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);

	/* take over all tx sgls from ctx */
	areq->tsgl = sock_kmalloc(sk, sizeof(areq->tsgl) sgl->cur,
	GFP_KERNEL);
	if (unlikely(!areq->tsgl))
	goto free;

	sg_init_table(areq->tsgl, sgl->cur);
	for (i = 0; i < sgl->cur; i++)
	sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]),
	sgl->sg[i].length, sgl->sg[i].offset);

	areq->tsgls = sgl->cur;

	/* create rx sgls */
	while (iov_iter_count(&msg->msg_iter)) {
	size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
	(outlen - usedpages));

	if (list_empty(&areq->list)) {
	rsgl = &areq->first_rsgl;

	} else {
	rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
	if (unlikely(!rsgl)) {
	err = -ENOMEM;
	goto free;
	}
	}
	rsgl->sgl.npages = 0;
	list_add_tail(&rsgl->list, &areq->list);

	/* make one iovec available as scatterlist */
	err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
	if (err < 0)
	goto free;

	usedpages += err;

	/* chain the new scatterlist with previous one */
	if (last_rsgl)
	af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);

	last_rsgl = rsgl;

	/* we do not need more iovecs as we have sufficient memory */
	if (outlen <= usedpages)
	break;

	iov_iter_advance(&msg->msg_iter, err);
	}
	err = -EINVAL;
	/* ensure output buffer is sufficiently large */
	if (usedpages < outlen)
	goto free;

	aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used,
	areq->iv);
	err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
	if (err) {
	if (err == -EINPROGRESS) {
	sock_hold(sk);
	err = -EIOCBQUEUED;
	aead_reset_ctx(ctx);
	goto unlock;
	} else if (err == -EBADMSG) {
	aead_put_sgl(sk);
	}
	goto free;
	}
	aead_put_sgl(sk);

	free:
	list_for_each_entry(rsgl, &areq->list, list) {
	af_alg_free_sg(&rsgl->sgl);
	if (rsgl != &areq->first_rsgl)
	sock_kfree_s(sk, rsgl, sizeof(*rsgl));
	}
	if (areq->tsgl)
	sock_kfree_s(sk, areq->tsgl, sizeof(areq->tsgl) areq->tsgls);
	if (req)
	sock_kfree_s(sk, req, reqlen);
	unlock:
	aead_wmem_wakeup(sk);
	release_sock(sk);
	return err ? err : outlen;
	}

	static int aead_recvmsg_sync(struct socket sock, struct msghdr msg, int flags)
	{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
	struct aead_sg_list *sgl = &ctx->tsgl;
	struct aead_async_rsgl *last_rsgl = NULL;
	struct aead_async_rsgl rsgl, tmp;
	int err = -EINVAL;
	unsigned long used = 0;
	size_t outlen = 0;
	size_t usedpages = 0;

	lock_sock(sk);

	/*
	* AEAD memory structure: For encryption, the tag is appended to the
	* ciphertext which implies that the memory allocated for the ciphertext
	* must be increased by the tag length. For decryption, the tag
	* is expected to be concatenated to the ciphertext. The plaintext
	* therefore has a memory size of the ciphertext minus the tag length.
	*
	* The memory structure for cipher operation has the following
	* structure:
	* AEAD encryption input: assoc data \|\| plaintext
	* AEAD encryption output: cipherntext \|\| auth tag
	* AEAD decryption input: assoc data \|\| ciphertext \|\| auth tag
	* AEAD decryption output: plaintext
	*/

	if (ctx->more) {
	err = aead_wait_for_data(sk, flags);
	if (err)
	goto unlock;
	}

	used = ctx->used;

	/*
	* Make sure sufficient data is present -- note, the same check is
	* is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
	* shall provide an information to the data sender that something is
	* wrong, but they are irrelevant to maintain the kernel integrity.
	* We need this check here too in case user space decides to not honor
	* the error message in sendmsg/sendpage and still call recvmsg. This
	* check here protects the kernel integrity.
	*/
	if (!aead_sufficient_data(ctx))
	goto unlock;

	outlen = used;

	/*
	* The cipher operation input data is reduced by the associated data
	* length as this data is processed separately later on.
	*/
	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);

	/* convert iovecs of output buffers into scatterlists */
	while (iov_iter_count(&msg->msg_iter)) {
	size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
	(outlen - usedpages));

	if (list_empty(&ctx->list)) {
	rsgl = &ctx->first_rsgl;
	} else {
	rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
	if (unlikely(!rsgl)) {
	err = -ENOMEM;
	goto unlock;
	}
	}
	rsgl->sgl.npages = 0;
	list_add_tail(&rsgl->list, &ctx->list);

	/* make one iovec available as scatterlist */
	err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
	if (err < 0)
	goto unlock;
	usedpages += err;
	/* chain the new scatterlist with previous one */
	if (last_rsgl)
	af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);

	last_rsgl = rsgl;

	/* we do not need more iovecs as we have sufficient memory */
	if (outlen <= usedpages)
	break;
	iov_iter_advance(&msg->msg_iter, err);
	}

	err = -EINVAL;
	/* ensure output buffer is sufficiently large */
	if (usedpages < outlen)
	goto unlock;

	sg_mark_end(sgl->sg + sgl->cur - 1);
	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
	used, ctx->iv);
	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);

	err = af_alg_wait_for_completion(ctx->enc ?
	crypto_aead_encrypt(&ctx->aead_req) :
	crypto_aead_decrypt(&ctx->aead_req),
	&ctx->completion);

	if (err) {
	/* EBADMSG implies a valid cipher operation took place */
	if (err == -EBADMSG)
	aead_put_sgl(sk);

	goto unlock;
	}

	aead_put_sgl(sk);
	err = 0;

	unlock:
	list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) {
	af_alg_free_sg(&rsgl->sgl);
	if (rsgl != &ctx->first_rsgl)
	sock_kfree_s(sk, rsgl, sizeof(*rsgl));
	list_del(&rsgl->list);
	}
	INIT_LIST_HEAD(&ctx->list);
	aead_wmem_wakeup(sk);
	release_sock(sk);

	return err ? err : outlen;
	}

	static int aead_recvmsg(struct socket sock, struct msghdr msg, size_t ignored,
	int flags)
	{
	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
	aead_recvmsg_async(sock, msg, flags) :
	aead_recvmsg_sync(sock, msg, flags);
	}

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

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

	if (!ctx->more)
	mask \|= POLLIN \| POLLRDNORM;

	if (aead_writable(sk))
	mask \|= POLLOUT \| POLLWRNORM \| POLLWRBAND;

	return mask;
	}

	static struct proto_ops algif_aead_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 = aead_sendmsg,
	.sendpage = aead_sendpage,
	.recvmsg = aead_recvmsg,
	.poll = aead_poll,
	};

	static void aead_bind(const char name, u32 type, u32 mask)
	{
	return crypto_alloc_aead(name, type, mask);
	}

	static void aead_release(void *private)
	{
	crypto_free_aead(private);
	}

	static int aead_setauthsize(void *private, unsigned int authsize)
	{
	return crypto_aead_setauthsize(private, authsize);
	}

	static int aead_setkey(void private, const u8 key, unsigned int keylen)
	{
	return crypto_aead_setkey(private, key, keylen);
	}

	static void aead_sock_destruct(struct sock *sk)
	{
	struct alg_sock *ask = alg_sk(sk);
	struct aead_ctx *ctx = ask->private;
	unsigned int ivlen = crypto_aead_ivsize(
	crypto_aead_reqtfm(&ctx->aead_req));

	WARN_ON(atomic_read(&sk->sk_refcnt) != 0);
	aead_put_sgl(sk);
	sock_kzfree_s(sk, ctx->iv, ivlen);
	sock_kfree_s(sk, ctx, ctx->len);
	af_alg_release_parent(sk);
	}

	static int aead_accept_parent(void private, struct sock sk)
	{
	struct aead_ctx *ctx;
	struct alg_sock *ask = alg_sk(sk);
	unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private);
	unsigned int ivlen = crypto_aead_ivsize(private);

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

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

	ctx->len = len;
	ctx->used = 0;
	ctx->more = 0;
	ctx->merge = 0;
	ctx->enc = 0;
	ctx->tsgl.cur = 0;
	ctx->aead_assoclen = 0;
	af_alg_init_completion(&ctx->completion);
	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
	INIT_LIST_HEAD(&ctx->list);

	ask->private = ctx;

	aead_request_set_tfm(&ctx->aead_req, private);
	aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
	af_alg_complete, &ctx->completion);

	sk->sk_destruct = aead_sock_destruct;

	return 0;
	}

	static const struct af_alg_type algif_type_aead = {
	.bind = aead_bind,
	.release = aead_release,
	.setkey = aead_setkey,
	.setauthsize = aead_setauthsize,
	.accept = aead_accept_parent,
	.ops = &algif_aead_ops,
	.name = "aead",
	.owner = THIS_MODULE
	};

	static int __init algif_aead_init(void)
	{
	return af_alg_register_type(&algif_type_aead);
	}

	static void __exit algif_aead_exit(void)
	{
	int err = af_alg_unregister_type(&algif_type_aead);
	BUG_ON(err);
	}

	module_init(algif_aead_init);
	module_exit(algif_aead_exit);
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
	MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");