[linux.git] / crypto / algif_skcipher.c

/*
 * algif_skcipher: User-space interface for skcipher algorithms
 *
 * This file provides the user-space API for symmetric key ciphers.
 *
 * Copyright (c) 2010 Herbert Xu <[email protected]>
 *
 * 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>
#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];
};

struct skcipher_ctx {
	struct list_head tsgl;
	struct af_alg_sgl rsgl;

	void *iv;

	struct af_alg_completion completion;

	unsigned used;

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

	struct ablkcipher_request req;
};

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

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

	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);
}

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)
			scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);

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

	return 0;
}

static void skcipher_pull_sgl(struct sock *sk, int used)
{
	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++) {
			int plen = min_t(int, used, sg[i].length);

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

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

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

			if (sg[i].length)
				return;

			put_page(sg_page(sg + i));
			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;

	skcipher_pull_sgl(sk, ctx->used);
}

static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
{
	long timeout;
	DEFINE_WAIT(wait);
	int err = -ERESTARTSYS;

	if (flags & MSG_DONTWAIT)
		return -EAGAIN;

	set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);

	for (;;) {
		if (signal_pending(current))
			break;
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
		timeout = MAX_SCHEDULE_TIMEOUT;
		if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
			err = 0;
			break;
		}
	}
	finish_wait(sk_sleep(sk), &wait);

	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);
	if (wq_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 skcipher_wait_for_data(struct sock *sk, unsigned flags)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	long timeout;
	DEFINE_WAIT(wait);
	int err = -ERESTARTSYS;

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

	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);

	for (;;) {
		if (signal_pending(current))
			break;
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
		timeout = MAX_SCHEDULE_TIMEOUT;
		if (sk_wait_event(sk, &timeout, ctx->used)) {
			err = 0;
			break;
		}
	}
	finish_wait(sk_sleep(sk), &wait);

	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);

	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);
	if (wq_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 skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
			    struct msghdr *msg, size_t size)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
	unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
	struct skcipher_sg_list *sgl;
	struct af_alg_control con = {};
	long copied = 0;
	bool enc = 0;
	bool init = 0;
	int err;
	int i;

	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;
	}

	err = -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);
	}

	while (size) {
		struct scatterlist *sg;
		unsigned long len = size;
		int plen;

		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);

			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 (!skcipher_writable(sk)) {
			err = skcipher_wait_for_wmem(sk, msg->msg_flags);
			if (err)
				goto unlock;
		}

		len = min_t(unsigned long, len, skcipher_sndbuf(sk));

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

		sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
		sg = sgl->sg;
		sg_unmark_end(sg + sgl->cur);
		do {
			i = sgl->cur;
			plen = min_t(int, len, PAGE_SIZE);

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

			err = memcpy_from_msg(page_address(sg_page(sg + i)),
					      msg, plen);
			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);

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

		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;

	if (flags & MSG_SENDPAGE_NOTLAST)
		flags |= MSG_MORE;

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

	if (!size)
		goto done;

	if (!skcipher_writable(sk)) {
		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);

	if (sgl->cur)
		sg_unmark_end(sgl->sg + sgl->cur - 1);

	sg_mark_end(sgl->sg + sgl->cur);
	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;
}

static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
			    struct msghdr *msg, size_t ignored, int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
		&ctx->req));
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	int err = -EAGAIN;
	int used;
	long copied = 0;

	lock_sock(sk);
	while (iov_iter_count(&msg->msg_iter)) {
		sgl = list_first_entry(&ctx->tsgl,
				       struct skcipher_sg_list, list);
		sg = sgl->sg;

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

		if (!ctx->used) {
			err = skcipher_wait_for_data(sk, flags);
			if (err)
				goto unlock;
		}

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

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

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

		err = -EINVAL;
		if (!used)
			goto free;

		ablkcipher_request_set_crypt(&ctx->req, sg,
					     ctx->rsgl.sg, used,
					     ctx->iv);

		err = af_alg_wait_for_completion(
				ctx->enc ?
					crypto_ablkcipher_encrypt(&ctx->req) :
					crypto_ablkcipher_decrypt(&ctx->req),
				&ctx->completion);

free:
		af_alg_free_sg(&ctx->rsgl);

		if (err)
			goto unlock;

		copied += used;
		skcipher_pull_sgl(sk, used);
		iov_iter_advance(&msg->msg_iter, used);
	}

	err = 0;

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

	return copied ?: err;
}


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,
};

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

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

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

static void skcipher_sock_destruct(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_ctx *ctx = ask->private;
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);

	skcipher_free_sgl(sk);
	sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
	sock_kfree_s(sk, ctx, ctx->len);
	af_alg_release_parent(sk);
}

static int skcipher_accept_parent(void *private, struct sock *sk)
{
	struct skcipher_ctx *ctx;
	struct alg_sock *ask = alg_sk(sk);
	unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);

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

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

	memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));

	INIT_LIST_HEAD(&ctx->tsgl);
	ctx->len = len;
	ctx->used = 0;
	ctx->more = 0;
	ctx->merge = 0;
	ctx->enc = 0;
	af_alg_init_completion(&ctx->completion);

	ask->private = ctx;

	ablkcipher_request_set_tfm(&ctx->req, private);
	ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
					af_alg_complete, &ctx->completion);

	sk->sk_destruct = skcipher_sock_destruct;

	return 0;
}

static const struct af_alg_type algif_type_skcipher = {
	.bind		=	skcipher_bind,
	.release	=	skcipher_release,
	.setkey		=	skcipher_setkey,
	.accept		=	skcipher_accept_parent,
	.ops		=	&algif_skcipher_ops,
	.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");
Commit	Line	Data
8ff59090 HX	1	/*
	2	* algif_skcipher: User-space interface for skcipher algorithms
	3	*
	4	* This file provides the user-space API for symmetric key ciphers.
	5	*
	6	* Copyright (c) 2010 Herbert Xu <[email protected]>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the Free
	10	* Software Foundation; either version 2 of the License, or (at your option)
	11	* any later version.
	12	*
	13	*/
	14
	15	#include <crypto/scatterwalk.h>
	16	#include <crypto/skcipher.h>
	17	#include <crypto/if_alg.h>
	18	#include <linux/init.h>
	19	#include <linux/list.h>
	20	#include <linux/kernel.h>
	21	#include <linux/mm.h>
	22	#include <linux/module.h>
	23	#include <linux/net.h>
	24	#include <net/sock.h>
	25
	26	struct skcipher_sg_list {
	27	struct list_head list;
	28
	29	int cur;
	30
	31	struct scatterlist sg[0];
	32	};
	33
	34	struct skcipher_ctx {
	35	struct list_head tsgl;
	36	struct af_alg_sgl rsgl;
	37
	38	void *iv;
	39
	40	struct af_alg_completion completion;
	41
	42	unsigned used;
	43
	44	unsigned int len;
	45	bool more;
	46	bool merge;
	47	bool enc;
	48
	49	struct ablkcipher_request req;
	50	};
	51
e2cffb5f	52	#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
8ff59090 HX	53	sizeof(struct scatterlist) - 1)
8ff59090 HX	54
0f6bb83c	55	static inline int skcipher_sndbuf(struct sock *sk)
8ff59090 HX	56	{
	57	struct alg_sock *ask = alg_sk(sk);
	58	struct skcipher_ctx *ctx = ask->private;
	59
0f6bb83c HX	60	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
	61	ctx->used, 0);
	62	}
	63
	64	static inline bool skcipher_writable(struct sock *sk)
	65	{
	66	return PAGE_SIZE <= skcipher_sndbuf(sk);
8ff59090 HX	67	}
	68
	69	static int skcipher_alloc_sgl(struct sock *sk)
	70	{
	71	struct alg_sock *ask = alg_sk(sk);
	72	struct skcipher_ctx *ctx = ask->private;
	73	struct skcipher_sg_list *sgl;
	74	struct scatterlist *sg = NULL;
	75
	76	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
	77	if (!list_empty(&ctx->tsgl))
	78	sg = sgl->sg;
	79
	80	if (!sg \|\| sgl->cur >= MAX_SGL_ENTS) {
	81	sgl = sock_kmalloc(sk, sizeof(*sgl) +
	82	sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
	83	GFP_KERNEL);
	84	if (!sgl)
	85	return -ENOMEM;
	86
	87	sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
	88	sgl->cur = 0;
	89
	90	if (sg)
	91	scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
	92
	93	list_add_tail(&sgl->list, &ctx->tsgl);
	94	}
	95
	96	return 0;
	97	}
	98
	99	static void skcipher_pull_sgl(struct sock *sk, int used)
	100	{
	101	struct alg_sock *ask = alg_sk(sk);
	102	struct skcipher_ctx *ctx = ask->private;
	103	struct skcipher_sg_list *sgl;
	104	struct scatterlist *sg;
	105	int i;
	106
	107	while (!list_empty(&ctx->tsgl)) {
	108	sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
	109	list);
	110	sg = sgl->sg;
	111
	112	for (i = 0; i < sgl->cur; i++) {
	113	int plen = min_t(int, used, sg[i].length);
	114
	115	if (!sg_page(sg + i))
	116	continue;
	117
	118	sg[i].length -= plen;
	119	sg[i].offset += plen;
	120
	121	used -= plen;
	122	ctx->used -= plen;
	123
	124	if (sg[i].length)
	125	return;
	126
	127	put_page(sg_page(sg + i));
	128	sg_assign_page(sg + i, NULL);
	129	}
	130
131	list_del(&sgl->list);
132	sock_kfree_s(sk, sgl,
133	sizeof(sgl) + sizeof(sgl->sg[0])
134	(MAX_SGL_ENTS + 1));
135	}
136
137	if (!ctx->used)
138	ctx->merge = 0;
139	}
140
141	static void skcipher_free_sgl(struct sock *sk)
142	{
143	struct alg_sock *ask = alg_sk(sk);
144	struct skcipher_ctx *ctx = ask->private;
145
146	skcipher_pull_sgl(sk, ctx->used);
147	}
148
149	static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
150	{
151	long timeout;
152	DEFINE_WAIT(wait);
153	int err = -ERESTARTSYS;
154
155	if (flags & MSG_DONTWAIT)
156	return -EAGAIN;
157
158	set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
159
160	for (;;) {
161	if (signal_pending(current))
162	break;
163	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
164	timeout = MAX_SCHEDULE_TIMEOUT;
165	if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
166	err = 0;
167	break;
168	}
169	}
170	finish_wait(sk_sleep(sk), &wait);
171
172	return err;
173	}
174
175	static void skcipher_wmem_wakeup(struct sock *sk)
176	{
177	struct socket_wq *wq;
178
179	if (!skcipher_writable(sk))
180	return;
181
182	rcu_read_lock();
183	wq = rcu_dereference(sk->sk_wq);
184	if (wq_has_sleeper(wq))
185	wake_up_interruptible_sync_poll(&wq->wait, POLLIN \|
186	POLLRDNORM \|
187	POLLRDBAND);
188	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
189	rcu_read_unlock();
190	}
191
192	static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
193	{
194	struct alg_sock *ask = alg_sk(sk);
195	struct skcipher_ctx *ctx = ask->private;
196	long timeout;
197	DEFINE_WAIT(wait);
198	int err = -ERESTARTSYS;
199
200	if (flags & MSG_DONTWAIT) {
201	return -EAGAIN;
202	}
203
204	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
205
206	for (;;) {
207	if (signal_pending(current))
208	break;
209	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
210	timeout = MAX_SCHEDULE_TIMEOUT;
211	if (sk_wait_event(sk, &timeout, ctx->used)) {
212	err = 0;
213	break;
214	}
215	}
216	finish_wait(sk_sleep(sk), &wait);
217
218	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
219
220	return err;
221	}
222
223	static void skcipher_data_wakeup(struct sock *sk)
224	{
225	struct alg_sock *ask = alg_sk(sk);
226	struct skcipher_ctx *ctx = ask->private;
227	struct socket_wq *wq;
228
229	if (!ctx->used)
230	return;
231
232	rcu_read_lock();
233	wq = rcu_dereference(sk->sk_wq);
234	if (wq_has_sleeper(wq))
235	wake_up_interruptible_sync_poll(&wq->wait, POLLOUT \|
236	POLLRDNORM \|
237	POLLRDBAND);
238	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
239	rcu_read_unlock();
240	}
241
242	static int skcipher_sendmsg(struct kiocb unused, struct socket sock,
243	struct msghdr *msg, size_t size)
244	{
245	struct sock *sk = sock->sk;
246	struct alg_sock *ask = alg_sk(sk);
247	struct skcipher_ctx *ctx = ask->private;
248	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
249	unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
250	struct skcipher_sg_list *sgl;
251	struct af_alg_control con = {};
252	long copied = 0;
253	bool enc = 0;
f26b7b80	254	bool init = 0;
8ff59090 HX	255	int err;
	256	int i;
	257
	258	if (msg->msg_controllen) {
	259	err = af_alg_cmsg_send(msg, &con);
	260	if (err)
	261	return err;
	262
f26b7b80	263	init = 1;
8ff59090 HX	264	switch (con.op) {
	265	case ALG_OP_ENCRYPT:
	266	enc = 1;
	267	break;
	268	case ALG_OP_DECRYPT:
	269	enc = 0;
	270	break;
	271	default:
	272	return -EINVAL;
	273	}
	274
	275	if (con.iv && con.iv->ivlen != ivsize)
	276	return -EINVAL;
	277	}
	278
	279	err = -EINVAL;
	280
	281	lock_sock(sk);
	282	if (!ctx->more && ctx->used)
	283	goto unlock;
	284
f26b7b80	285	if (init) {
8ff59090 HX	286	ctx->enc = enc;
	287	if (con.iv)
	288	memcpy(ctx->iv, con.iv->iv, ivsize);
	289	}
	290
8ff59090 HX	291	while (size) {
	292	struct scatterlist *sg;
	293	unsigned long len = size;
	294	int plen;
	295
	296	if (ctx->merge) {
	297	sgl = list_entry(ctx->tsgl.prev,
	298	struct skcipher_sg_list, list);
	299	sg = sgl->sg + sgl->cur - 1;
	300	len = min_t(unsigned long, len,
	301	PAGE_SIZE - sg->offset - sg->length);
	302
6ce8e9ce AV	303	err = memcpy_from_msg(page_address(sg_page(sg)) +
	304	sg->offset + sg->length,
	305	msg, len);
8ff59090 HX	306	if (err)
	307	goto unlock;
	308
	309	sg->length += len;
	310	ctx->merge = (sg->offset + sg->length) &
	311	(PAGE_SIZE - 1);
	312
	313	ctx->used += len;
	314	copied += len;
	315	size -= len;
8ff59090 HX	316	continue;
	317	}
	318
0f6bb83c	319	if (!skcipher_writable(sk)) {
8ff59090 HX	320	err = skcipher_wait_for_wmem(sk, msg->msg_flags);
	321	if (err)
	322	goto unlock;
8ff59090 HX	323	}
8ff59090 HX	324
0f6bb83c	325	len = min_t(unsigned long, len, skcipher_sndbuf(sk));
8ff59090 HX	326
	327	err = skcipher_alloc_sgl(sk);
	328	if (err)
	329	goto unlock;
	330
	331	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
	332	sg = sgl->sg;
0f477b65	333	sg_unmark_end(sg + sgl->cur);
8ff59090 HX	334	do {
	335	i = sgl->cur;
	336	plen = min_t(int, len, PAGE_SIZE);
	337
	338	sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
	339	err = -ENOMEM;
	340	if (!sg_page(sg + i))
	341	goto unlock;
	342
6ce8e9ce AV	343	err = memcpy_from_msg(page_address(sg_page(sg + i)),
6ce8e9ce AV	344	msg, plen);
8ff59090 HX	345	if (err) {
	346	__free_page(sg_page(sg + i));
	347	sg_assign_page(sg + i, NULL);
	348	goto unlock;
	349	}
	350
	351	sg[i].length = plen;
	352	len -= plen;
	353	ctx->used += plen;
	354	copied += plen;
	355	size -= plen;
8ff59090 HX	356	sgl->cur++;
	357	} while (len && sgl->cur < MAX_SGL_ENTS);
	358
0f477b65 TS	359	if (!size)
	360	sg_mark_end(sg + sgl->cur - 1);
	361
8ff59090 HX	362	ctx->merge = plen & (PAGE_SIZE - 1);
	363	}
	364
	365	err = 0;
	366
	367	ctx->more = msg->msg_flags & MSG_MORE;
8ff59090 HX	368
	369	unlock:
	370	skcipher_data_wakeup(sk);
	371	release_sock(sk);
	372
	373	return copied ?: err;
	374	}
	375
	376	static ssize_t skcipher_sendpage(struct socket sock, struct page page,
	377	int offset, size_t size, int flags)
	378	{
	379	struct sock *sk = sock->sk;
	380	struct alg_sock *ask = alg_sk(sk);
	381	struct skcipher_ctx *ctx = ask->private;
	382	struct skcipher_sg_list *sgl;
	383	int err = -EINVAL;
8ff59090	384
d3f7d56a SL	385	if (flags & MSG_SENDPAGE_NOTLAST)
	386	flags \|= MSG_MORE;
	387
8ff59090 HX	388	lock_sock(sk);
	389	if (!ctx->more && ctx->used)
	390	goto unlock;
	391
	392	if (!size)
	393	goto done;
	394
0f6bb83c	395	if (!skcipher_writable(sk)) {
8ff59090 HX	396	err = skcipher_wait_for_wmem(sk, flags);
	397	if (err)
	398	goto unlock;
8ff59090 HX	399	}
	400
	401	err = skcipher_alloc_sgl(sk);
	402	if (err)
	403	goto unlock;
	404
	405	ctx->merge = 0;
	406	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
	407
0f477b65 TS	408	if (sgl->cur)
	409	sg_unmark_end(sgl->sg + sgl->cur - 1);
	410
	411	sg_mark_end(sgl->sg + sgl->cur);
8ff59090 HX	412	get_page(page);
	413	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
	414	sgl->cur++;
	415	ctx->used += size;
	416
	417	done:
	418	ctx->more = flags & MSG_MORE;
8ff59090 HX	419
	420	unlock:
	421	skcipher_data_wakeup(sk);
	422	release_sock(sk);
	423
	424	return err ?: size;
	425	}
	426
	427	static int skcipher_recvmsg(struct kiocb unused, struct socket sock,
	428	struct msghdr *msg, size_t ignored, int flags)
	429	{
	430	struct sock *sk = sock->sk;
	431	struct alg_sock *ask = alg_sk(sk);
	432	struct skcipher_ctx *ctx = ask->private;
	433	unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
	434	&ctx->req));
	435	struct skcipher_sg_list *sgl;
	436	struct scatterlist *sg;
8ff59090 HX	437	int err = -EAGAIN;
	438	int used;
	439	long copied = 0;
	440
	441	lock_sock(sk);
1d10eb2f AV	442	while (iov_iter_count(&msg->msg_iter)) {
	443	sgl = list_first_entry(&ctx->tsgl,
	444	struct skcipher_sg_list, list);
	445	sg = sgl->sg;
8ff59090	446
1d10eb2f AV	447	while (!sg->length)
1d10eb2f AV	448	sg++;
8ff59090	449
9399f0c5	450	if (!ctx->used) {
1d10eb2f AV	451	err = skcipher_wait_for_data(sk, flags);
1d10eb2f AV	452	if (err)
bc97e57e	453	goto unlock;
1d10eb2f AV	454	}
1d10eb2f AV	455
9399f0c5	456	used = min_t(unsigned long, ctx->used, iov_iter_count(&msg->msg_iter));
1d10eb2f AV	457
	458	used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
	459	err = used;
	460	if (err < 0)
	461	goto unlock;
bc97e57e	462
1d10eb2f AV	463	if (ctx->more \|\| used < ctx->used)
1d10eb2f AV	464	used -= used % bs;
8ff59090	465
1d10eb2f AV	466	err = -EINVAL;
	467	if (!used)
	468	goto free;
8ff59090	469
1d10eb2f AV	470	ablkcipher_request_set_crypt(&ctx->req, sg,
	471	ctx->rsgl.sg, used,
	472	ctx->iv);
8ff59090	473
1d10eb2f	474	err = af_alg_wait_for_completion(
8ff59090 HX	475	ctx->enc ?
	476	crypto_ablkcipher_encrypt(&ctx->req) :
	477	crypto_ablkcipher_decrypt(&ctx->req),
	478	&ctx->completion);
	479
bc97e57e	480	free:
1d10eb2f	481	af_alg_free_sg(&ctx->rsgl);
8ff59090	482
1d10eb2f AV	483	if (err)
1d10eb2f AV	484	goto unlock;
8ff59090	485
1d10eb2f AV	486	copied += used;
	487	skcipher_pull_sgl(sk, used);
	488	iov_iter_advance(&msg->msg_iter, used);
8ff59090 HX	489	}
	490
	491	err = 0;
	492
	493	unlock:
	494	skcipher_wmem_wakeup(sk);
	495	release_sock(sk);
	496
	497	return copied ?: err;
	498	}
	499
	500
	501	static unsigned int skcipher_poll(struct file file, struct socket sock,
	502	poll_table *wait)
	503	{
	504	struct sock *sk = sock->sk;
	505	struct alg_sock *ask = alg_sk(sk);
	506	struct skcipher_ctx *ctx = ask->private;
	507	unsigned int mask;
	508
	509	sock_poll_wait(file, sk_sleep(sk), wait);
	510	mask = 0;
	511
	512	if (ctx->used)
	513	mask \|= POLLIN \| POLLRDNORM;
	514
	515	if (skcipher_writable(sk))
	516	mask \|= POLLOUT \| POLLWRNORM \| POLLWRBAND;
	517
	518	return mask;
	519	}
	520
	521	static struct proto_ops algif_skcipher_ops = {
	522	.family = PF_ALG,
	523
	524	.connect = sock_no_connect,
	525	.socketpair = sock_no_socketpair,
	526	.getname = sock_no_getname,
	527	.ioctl = sock_no_ioctl,
	528	.listen = sock_no_listen,
	529	.shutdown = sock_no_shutdown,
	530	.getsockopt = sock_no_getsockopt,
	531	.mmap = sock_no_mmap,
	532	.bind = sock_no_bind,
	533	.accept = sock_no_accept,
	534	.setsockopt = sock_no_setsockopt,
	535
	536	.release = af_alg_release,
	537	.sendmsg = skcipher_sendmsg,
	538	.sendpage = skcipher_sendpage,
	539	.recvmsg = skcipher_recvmsg,
	540	.poll = skcipher_poll,
	541	};
	542
	543	static void skcipher_bind(const char name, u32 type, u32 mask)
	544	{
	545	return crypto_alloc_ablkcipher(name, type, mask);
	546	}
	547
	548	static void skcipher_release(void *private)
	549	{
	550	crypto_free_ablkcipher(private);
	551	}
	552
553	static int skcipher_setkey(void private, const u8 key, unsigned int keylen)
554	{
555	return crypto_ablkcipher_setkey(private, key, keylen);
556	}
557
558	static void skcipher_sock_destruct(struct sock *sk)
559	{
560	struct alg_sock *ask = alg_sk(sk);
561	struct skcipher_ctx *ctx = ask->private;
562	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
563
564	skcipher_free_sgl(sk);
79e88659	565	sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
8ff59090 HX	566	sock_kfree_s(sk, ctx, ctx->len);
	567	af_alg_release_parent(sk);
	568	}
	569
	570	static int skcipher_accept_parent(void private, struct sock sk)
	571	{
	572	struct skcipher_ctx *ctx;
	573	struct alg_sock *ask = alg_sk(sk);
	574	unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);
	575
	576	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
	577	if (!ctx)
	578	return -ENOMEM;
	579
	580	ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private),
	581	GFP_KERNEL);
	582	if (!ctx->iv) {
	583	sock_kfree_s(sk, ctx, len);
	584	return -ENOMEM;
	585	}
	586
	587	memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));
	588
	589	INIT_LIST_HEAD(&ctx->tsgl);
	590	ctx->len = len;
	591	ctx->used = 0;
	592	ctx->more = 0;
	593	ctx->merge = 0;
	594	ctx->enc = 0;
	595	af_alg_init_completion(&ctx->completion);
	596
	597	ask->private = ctx;
	598
	599	ablkcipher_request_set_tfm(&ctx->req, private);
	600	ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
	601	af_alg_complete, &ctx->completion);
	602
	603	sk->sk_destruct = skcipher_sock_destruct;
	604
	605	return 0;
	606	}
	607
	608	static const struct af_alg_type algif_type_skcipher = {
	609	.bind = skcipher_bind,
	610	.release = skcipher_release,
	611	.setkey = skcipher_setkey,
	612	.accept = skcipher_accept_parent,
	613	.ops = &algif_skcipher_ops,
	614	.name = "skcipher",
	615	.owner = THIS_MODULE
	616	};
	617
	618	static int __init algif_skcipher_init(void)
	619	{
	620	return af_alg_register_type(&algif_type_skcipher);
	621	}
	622
	623	static void __exit algif_skcipher_exit(void)
	624	{
	625	int err = af_alg_unregister_type(&algif_type_skcipher);
	626	BUG_ON(err);
	627	}
	628
	629	module_init(algif_skcipher_init);
630	module_exit(algif_skcipher_exit);
631	MODULE_LICENSE("GPL");