xref: /kernel/linux/linux-5.10/crypto/scompress.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Synchronous Compression operations
4 *
5 * Copyright 2015 LG Electronics Inc.
6 * Copyright (c) 2016, Intel Corporation
7 * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
8 */
9#include <linux/errno.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/seq_file.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <linux/crypto.h>
16#include <linux/compiler.h>
17#include <linux/vmalloc.h>
18#include <crypto/algapi.h>
19#include <linux/cryptouser.h>
20#include <net/netlink.h>
21#include <linux/scatterlist.h>
22#include <crypto/scatterwalk.h>
23#include <crypto/internal/acompress.h>
24#include <crypto/internal/scompress.h>
25#include "internal.h"
26
27struct scomp_scratch {
28	spinlock_t	lock;
29	void		*src;
30	void		*dst;
31};
32
33static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
34	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
35};
36
37static const struct crypto_type crypto_scomp_type;
38static int scomp_scratch_users;
39static DEFINE_MUTEX(scomp_lock);
40
41#ifdef CONFIG_NET
42static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
43{
44	struct crypto_report_comp rscomp;
45
46	memset(&rscomp, 0, sizeof(rscomp));
47
48	strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
49
50	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
51		       sizeof(rscomp), &rscomp);
52}
53#else
54static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
55{
56	return -ENOSYS;
57}
58#endif
59
60static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
61	__maybe_unused;
62
63static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
64{
65	seq_puts(m, "type         : scomp\n");
66}
67
68static void crypto_scomp_free_scratches(void)
69{
70	struct scomp_scratch *scratch;
71	int i;
72
73	for_each_possible_cpu(i) {
74		scratch = per_cpu_ptr(&scomp_scratch, i);
75
76		vfree(scratch->src);
77		vfree(scratch->dst);
78		scratch->src = NULL;
79		scratch->dst = NULL;
80	}
81}
82
83static int crypto_scomp_alloc_scratches(void)
84{
85	struct scomp_scratch *scratch;
86	int i;
87
88	for_each_possible_cpu(i) {
89		void *mem;
90
91		scratch = per_cpu_ptr(&scomp_scratch, i);
92
93		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
94		if (!mem)
95			goto error;
96		scratch->src = mem;
97		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
98		if (!mem)
99			goto error;
100		scratch->dst = mem;
101	}
102	return 0;
103error:
104	crypto_scomp_free_scratches();
105	return -ENOMEM;
106}
107
108static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
109{
110	int ret = 0;
111
112	mutex_lock(&scomp_lock);
113	if (!scomp_scratch_users++)
114		ret = crypto_scomp_alloc_scratches();
115	mutex_unlock(&scomp_lock);
116
117	return ret;
118}
119
120static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
121{
122	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
123	void **tfm_ctx = acomp_tfm_ctx(tfm);
124	struct crypto_scomp *scomp = *tfm_ctx;
125	void **ctx = acomp_request_ctx(req);
126	struct scomp_scratch *scratch;
127	unsigned int dlen;
128	int ret;
129
130	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
131		return -EINVAL;
132
133	if (req->dst && !req->dlen)
134		return -EINVAL;
135
136	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
137		req->dlen = SCOMP_SCRATCH_SIZE;
138
139	dlen = req->dlen;
140
141	scratch = raw_cpu_ptr(&scomp_scratch);
142	spin_lock(&scratch->lock);
143
144	scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
145	if (dir)
146		ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
147					    scratch->dst, &req->dlen, *ctx);
148	else
149		ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
150					      scratch->dst, &req->dlen, *ctx);
151	if (!ret) {
152		if (!req->dst) {
153			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
154			if (!req->dst) {
155				ret = -ENOMEM;
156				goto out;
157			}
158		} else if (req->dlen > dlen) {
159			ret = -ENOSPC;
160			goto out;
161		}
162		scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
163					 1);
164	}
165out:
166	spin_unlock(&scratch->lock);
167	return ret;
168}
169
170static int scomp_acomp_compress(struct acomp_req *req)
171{
172	return scomp_acomp_comp_decomp(req, 1);
173}
174
175static int scomp_acomp_decompress(struct acomp_req *req)
176{
177	return scomp_acomp_comp_decomp(req, 0);
178}
179
180static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
181{
182	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
183
184	crypto_free_scomp(*ctx);
185
186	mutex_lock(&scomp_lock);
187	if (!--scomp_scratch_users)
188		crypto_scomp_free_scratches();
189	mutex_unlock(&scomp_lock);
190}
191
192int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
193{
194	struct crypto_alg *calg = tfm->__crt_alg;
195	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
196	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
197	struct crypto_scomp *scomp;
198
199	if (!crypto_mod_get(calg))
200		return -EAGAIN;
201
202	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
203	if (IS_ERR(scomp)) {
204		crypto_mod_put(calg);
205		return PTR_ERR(scomp);
206	}
207
208	*ctx = scomp;
209	tfm->exit = crypto_exit_scomp_ops_async;
210
211	crt->compress = scomp_acomp_compress;
212	crt->decompress = scomp_acomp_decompress;
213	crt->dst_free = sgl_free;
214	crt->reqsize = sizeof(void *);
215
216	return 0;
217}
218
219struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
220{
221	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
222	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
223	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
224	struct crypto_scomp *scomp = *tfm_ctx;
225	void *ctx;
226
227	ctx = crypto_scomp_alloc_ctx(scomp);
228	if (IS_ERR(ctx)) {
229		kfree(req);
230		return NULL;
231	}
232
233	*req->__ctx = ctx;
234
235	return req;
236}
237
238void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
239{
240	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
241	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
242	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
243	struct crypto_scomp *scomp = *tfm_ctx;
244	void *ctx = *req->__ctx;
245
246	if (ctx)
247		crypto_scomp_free_ctx(scomp, ctx);
248}
249
250static const struct crypto_type crypto_scomp_type = {
251	.extsize = crypto_alg_extsize,
252	.init_tfm = crypto_scomp_init_tfm,
253#ifdef CONFIG_PROC_FS
254	.show = crypto_scomp_show,
255#endif
256	.report = crypto_scomp_report,
257	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
258	.maskset = CRYPTO_ALG_TYPE_MASK,
259	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
260	.tfmsize = offsetof(struct crypto_scomp, base),
261};
262
263int crypto_register_scomp(struct scomp_alg *alg)
264{
265	struct crypto_alg *base = &alg->base;
266
267	base->cra_type = &crypto_scomp_type;
268	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
269	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
270
271	return crypto_register_alg(base);
272}
273EXPORT_SYMBOL_GPL(crypto_register_scomp);
274
275void crypto_unregister_scomp(struct scomp_alg *alg)
276{
277	crypto_unregister_alg(&alg->base);
278}
279EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
280
281int crypto_register_scomps(struct scomp_alg *algs, int count)
282{
283	int i, ret;
284
285	for (i = 0; i < count; i++) {
286		ret = crypto_register_scomp(&algs[i]);
287		if (ret)
288			goto err;
289	}
290
291	return 0;
292
293err:
294	for (--i; i >= 0; --i)
295		crypto_unregister_scomp(&algs[i]);
296
297	return ret;
298}
299EXPORT_SYMBOL_GPL(crypto_register_scomps);
300
301void crypto_unregister_scomps(struct scomp_alg *algs, int count)
302{
303	int i;
304
305	for (i = count - 1; i >= 0; --i)
306		crypto_unregister_scomp(&algs[i]);
307}
308EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
309
310MODULE_LICENSE("GPL");
311MODULE_DESCRIPTION("Synchronous compression type");
312