Release 4.11 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 <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/scatterwalk.h>
#include <crypto/skcipher.h>
#include <crypto/if_alg.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/sched/signal.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_tfm {
	
struct crypto_skcipher *skcipher;
	
bool has_key;
};


struct skcipher_ctx {
	
struct list_head tsgl;
	
struct af_alg_sgl rsgl;

	
void *iv;

	
struct af_alg_completion completion;

	
atomic_t inflight;
	
size_t used;

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

	
struct skcipher_request req;
};


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


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


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



static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
{
	struct skcipher_async_rsgl *rsgl, *tmp;
	struct scatterlist *sgl;
	struct scatterlist *sg;
	int i, n;

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

	kfree(sreq->tsg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tadeusz Struk
106
100.00%
1
100.00%
Total
106
100.00%
1
100.00%



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

	atomic_dec(sreq->inflight);
	skcipher_free_async_sgls(sreq);
	kzfree(sreq);
	iocb->ki_complete(iocb, err, err);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tadeusz Struk
52
86.67%
1
33.33%
Herbert Xu
5
8.33%
1
33.33%
Al Viro
3
5.00%
1
33.33%
Total
60
100.00%
3
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
56
100.00%
2
100.00%
Total
56
100.00%
2
100.00%



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
20
100.00%
2
100.00%
Total
20
100.00%
2
100.00%



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

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

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
177
99.44%
1
50.00%
Dan J Williams
1
0.56%
1
50.00%
Total
178
100.00%
2
100.00%



static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
{
	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++) {
			size_t plen = min_t(size_t, 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;
			if (put)
				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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
229
95.82%
1
33.33%
Tadeusz Struk
7
2.93%
1
33.33%
Corentin Labbe
3
1.26%
1
33.33%
Total
239
100.00%
3
100.00%



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, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
39
95.12%
1
50.00%
Tadeusz Struk
2
4.88%
1
50.00%
Total
41
100.00%
2
100.00%



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

	if (flags & MSG_DONTWAIT)
		return -EAGAIN;

	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);

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

	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
93
80.17%
1
33.33%
Américo Wang
21
18.10%
1
33.33%
Eric Dumazet
2
1.72%
1
33.33%
Total
116
100.00%
3
100.00%



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 (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();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
70
100.00%
2
100.00%
Total
70
100.00%
2
100.00%



static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct alg_sock *ask = alg_sk(sk);
	struct skcipher_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->used, &wait)) {
			err = 0;
			break;
		}
	}
	remove_wait_queue(sk_sleep(sk), &wait);

	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);

	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
117
81.82%
1
33.33%
Américo Wang
22
15.38%
1
33.33%
Eric Dumazet
4
2.80%
1
33.33%
Total
143
100.00%
3
100.00%



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 (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();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
88
100.00%
2
100.00%
Total
88
100.00%
2
100.00%



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 skcipher_ctx *ctx = ask->private;
	struct skcipher_tfm *skc = pask->private;
	struct crypto_skcipher *tfm = skc->skcipher;
	unsigned ivsize = crypto_skcipher_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;
		size_t 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;
		if (sgl->cur)
			sg_unmark_end(sg + sgl->cur - 1);
		do {
			i = sgl->cur;
			plen = min_t(size_t, 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
650
94.34%
5
55.56%
Tadeusz Struk
25
3.63%
1
11.11%
Stephan Mueller
10
1.45%
1
11.11%
Al Viro
2
0.29%
1
11.11%
Corentin Labbe
2
0.29%
1
11.11%
Total
689
100.00%
9
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Herbert Xu
214
84.25%
2
50.00%
Tadeusz Struk
30
11.81%
1
25.00%
Shawn Landden
10
3.94%
1
25.00%
Total
254
100.00%
4
100.00%



static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
{
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	int nents = 0;

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

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

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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tadeusz Struk
49
79.03%
1
50.00%
Herbert Xu
13
20.97%
1
50.00%
Total
62
100.00%
2
100.00%



static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
				  int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct sock *psk = ask->parent;
	struct alg_sock *pask = alg_sk(psk);
	struct skcipher_ctx *ctx = ask->private;
	struct skcipher_tfm *skc = pask->private;
	struct crypto_skcipher *tfm = skc->skcipher;
	struct skcipher_sg_list *sgl;
	struct scatterlist *sg;
	struct skcipher_async_req *sreq;
	struct skcipher_request *req;
	struct skcipher_async_rsgl *last_rsgl = NULL;
	unsigned int txbufs = 0, len = 0, tx_nents;
	unsigned int reqsize = crypto_skcipher_reqsize(tfm);
	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
	int err = -ENOMEM;
	bool mark = false;
	char *iv;

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

	req = &sreq->req;
	iv = (char *)(req + 1) + reqsize;
	sreq->iocb = msg->msg_iocb;
	INIT_LIST_HEAD(&sreq->list);
	sreq->inflight = &ctx->inflight;

	lock_sock(sk);
	tx_nents = skcipher_all_sg_nents(ctx);
	sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
	if (unlikely(!sreq->tsg))
		goto unlock;
	sg_init_table(sreq->tsg, tx_nents);
	memcpy(iv, ctx->iv, ivsize);
	skcipher_request_set_tfm(req, tfm);
	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
				      skcipher_async_cb, sreq);

	while (iov_iter_count(&msg->msg_iter)) {
		struct skcipher_async_rsgl *rsgl;
		int used;

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

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

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

		if (txbufs == tx_nents) {
			struct scatterlist *tmp;
			int x;
			/* Ran out of tx slots in async request
                         * need to expand */
			tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
				      GFP_KERNEL);
			if (!tmp) {
				err = -ENOMEM;
				goto free;
			}

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

		if (list_empty(&sreq->list)) {
			rsgl = &sreq->first_sgl;
			list_add_tail(&rsgl->list, &sreq->list);
		} else {
			rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
			if (!rsgl) {
				err = -ENOMEM;
				goto free