aboutsummaryrefslogtreecommitdiff
path: root/crypto/scompress.c
blob: 6b048b36312dac5f97b47e56765fc7ed9d686aa5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
/*
 * Synchronous Compression operations
 *
 * Copyright 2015 LG Electronics Inc.
 * Copyright (c) 2016, Intel Corporation
 * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
 *
 * 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 <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <linux/compiler.h>
#include <linux/vmalloc.h>
#include <crypto/algapi.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/acompress.h>
#include <crypto/internal/scompress.h>
#include "internal.h"

static const struct crypto_type crypto_scomp_type;
static void * __percpu *scomp_src_scratches;
static void * __percpu *scomp_dst_scratches;
static int scomp_scratch_users;
static DEFINE_MUTEX(scomp_lock);

#ifdef CONFIG_NET
static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_comp rscomp;

	strncpy(rscomp.type, "scomp", sizeof(rscomp.type));

	if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
		    sizeof(struct crypto_report_comp), &rscomp))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}
#else
static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
	__maybe_unused;

static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
{
	seq_puts(m, "type         : scomp\n");
}

static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
{
	return 0;
}

static void crypto_scomp_free_scratches(void * __percpu *scratches)
{
	int i;

	if (!scratches)
		return;

	for_each_possible_cpu(i)
		vfree(*per_cpu_ptr(scratches, i));

	free_percpu(scratches);
}

static void * __percpu *crypto_scomp_alloc_scratches(void)
{
	void * __percpu *scratches;
	int i;

	scratches = alloc_percpu(void *);
	if (!scratches)
		return NULL;

	for_each_possible_cpu(i) {
		void *scratch;

		scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
		if (!scratch)
			goto error;
		*per_cpu_ptr(scratches, i) = scratch;
	}

	return scratches;

error:
	crypto_scomp_free_scratches(scratches);
	return NULL;
}

static void crypto_scomp_free_all_scratches(void)
{
	if (!--scomp_scratch_users) {
		crypto_scomp_free_scratches(scomp_src_scratches);
		crypto_scomp_free_scratches(scomp_dst_scratches);
		scomp_src_scratches = NULL;
		scomp_dst_scratches = NULL;
	}
}

static int crypto_scomp_alloc_all_scratches(void)
{
	if (!scomp_scratch_users++) {
		scomp_src_scratches = crypto_scomp_alloc_scratches();
		if (!scomp_src_scratches)
			return -ENOMEM;
		scomp_dst_scratches = crypto_scomp_alloc_scratches();
		if (!scomp_dst_scratches)
			return -ENOMEM;
	}
	return 0;
}

static void crypto_scomp_sg_free(struct scatterlist *sgl)
{
	int i, n;
	struct page *page;

	if (!sgl)
		return;

	n = sg_nents(sgl);
	for_each_sg(sgl, sgl, n, i) {
		page = sg_page(sgl);
		if (page)
			__free_page(page);
	}

	kfree(sgl);
}

static struct scatterlist *crypto_scomp_sg_alloc(size_t size, gfp_t gfp)
{
	struct scatterlist *sgl;
	struct page *page;
	int i, n;

	n = ((size - 1) >> PAGE_SHIFT) + 1;

	sgl = kmalloc_array(n, sizeof(struct scatterlist), gfp);
	if (!sgl)
		return NULL;

	sg_init_table(sgl, n);

	for (i = 0; i < n; i++) {
		page = alloc_page(gfp);
		if (!page)
			goto err;
		sg_set_page(sgl + i, page, PAGE_SIZE, 0);
	}

	return sgl;

err:
	sg_mark_end(sgl + i);
	crypto_scomp_sg_free(sgl);
	return NULL;
}

static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
{
	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
	void **tfm_ctx = acomp_tfm_ctx(tfm);
	struct crypto_scomp *scomp = *tfm_ctx;
	void **ctx = acomp_request_ctx(req);
	const int cpu = get_cpu();
	u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
	u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
	int ret;

	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
		ret = -EINVAL;
		goto out;
	}

	if (req->dst && !req->dlen) {
		ret = -EINVAL;
		goto out;
	}

	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
		req->dlen = SCOMP_SCRATCH_SIZE;

	scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
	if (dir)
		ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
					    scratch_dst, &req->dlen, *ctx);
	else
		ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
					      scratch_dst, &req->dlen, *ctx);
	if (!ret) {
		if (!req->dst) {
			req->dst = crypto_scomp_sg_alloc(req->dlen,
				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
				   GFP_KERNEL : GFP_ATOMIC);
			if (!req->dst)
				goto out;
		}
		scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
					 1);
	}
out:
	put_cpu();
	return ret;
}

static int scomp_acomp_compress(struct acomp_req *req)
{
	return scomp_acomp_comp_decomp(req, 1);
}

static int scomp_acomp_decompress(struct acomp_req *req)
{
	return scomp_acomp_comp_decomp(req, 0);
}

static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
{
	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);

	crypto_free_scomp(*ctx);
}

int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
{
	struct crypto_alg *calg = tfm->__crt_alg;
	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
	struct crypto_scomp *scomp;

	if (!crypto_mod_get(calg))
		return -EAGAIN;

	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
	if (IS_ERR(scomp)) {
		crypto_mod_put(calg);
		return PTR_ERR(scomp);
	}

	*ctx = scomp;
	tfm->exit = crypto_exit_scomp_ops_async;

	crt->compress = scomp_acomp_compress;
	crt->decompress = scomp_acomp_decompress;
	crt->dst_free = crypto_scomp_sg_free;
	crt->reqsize = sizeof(void *);

	return 0;
}

struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
{
	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
	struct crypto_scomp *scomp = *tfm_ctx;
	void *ctx;

	ctx = crypto_scomp_alloc_ctx(scomp);
	if (IS_ERR(ctx)) {
		kfree(req);
		return NULL;
	}

	*req->__ctx = ctx;

	return req;
}

void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
{
	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
	struct crypto_scomp *scomp = *tfm_ctx;
	void *ctx = *req->__ctx;

	if (ctx)
		crypto_scomp_free_ctx(scomp, ctx);
}

static const struct crypto_type crypto_scomp_type = {
	.extsize = crypto_alg_extsize,
	.init_tfm = crypto_scomp_init_tfm,
#ifdef CONFIG_PROC_FS
	.show = crypto_scomp_show,
#endif
	.report = crypto_scomp_report,
	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
	.maskset = CRYPTO_ALG_TYPE_MASK,
	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
	.tfmsize = offsetof(struct crypto_scomp, base),
};

int crypto_register_scomp(struct scomp_alg *alg)
{
	struct crypto_alg *base = &alg->base;
	int ret = -ENOMEM;

	mutex_lock(&scomp_lock);
	if (crypto_scomp_alloc_all_scratches())
		goto error;

	base->cra_type = &crypto_scomp_type;
	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;

	ret = crypto_register_alg(base);
	if (ret)
		goto error;

	mutex_unlock(&scomp_lock);
	return ret;

error:
	crypto_scomp_free_all_scratches();
	mutex_unlock(&scomp_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_scomp);

int crypto_unregister_scomp(struct scomp_alg *alg)
{
	int ret;

	mutex_lock(&scomp_lock);
	ret = crypto_unregister_alg(&alg->base);
	crypto_scomp_free_all_scratches();
	mutex_unlock(&scomp_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(crypto_unregister_scomp);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Synchronous compression type");