xref: /linux/crypto/scompress.c (revision 40d269c000bda9fcd276a0412a9cebd3f6e344c5)
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 
10 #include <crypto/internal/acompress.h>
11 #include <crypto/internal/scompress.h>
12 #include <crypto/scatterwalk.h>
13 #include <linux/cryptouser.h>
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/scatterlist.h>
18 #include <linux/seq_file.h>
19 #include <linux/slab.h>
20 #include <linux/string.h>
21 #include <linux/vmalloc.h>
22 #include <net/netlink.h>
23 
24 #include "compress.h"
25 
26 struct scomp_scratch {
27 	spinlock_t	lock;
28 	void		*src;
29 	void		*dst;
30 };
31 
32 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
33 	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
34 };
35 
36 static const struct crypto_type crypto_scomp_type;
37 static int scomp_scratch_users;
38 static DEFINE_MUTEX(scomp_lock);
39 
40 static int __maybe_unused crypto_scomp_report(
41 	struct sk_buff *skb, struct crypto_alg *alg)
42 {
43 	struct crypto_report_comp rscomp;
44 
45 	memset(&rscomp, 0, sizeof(rscomp));
46 
47 	strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
48 
49 	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
50 		       sizeof(rscomp), &rscomp);
51 }
52 
53 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
54 	__maybe_unused;
55 
56 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
57 {
58 	seq_puts(m, "type         : scomp\n");
59 }
60 
61 static void crypto_scomp_free_scratches(void)
62 {
63 	struct scomp_scratch *scratch;
64 	int i;
65 
66 	for_each_possible_cpu(i) {
67 		scratch = per_cpu_ptr(&scomp_scratch, i);
68 
69 		vfree(scratch->src);
70 		vfree(scratch->dst);
71 		scratch->src = NULL;
72 		scratch->dst = NULL;
73 	}
74 }
75 
76 static int crypto_scomp_alloc_scratches(void)
77 {
78 	struct scomp_scratch *scratch;
79 	int i;
80 
81 	for_each_possible_cpu(i) {
82 		void *mem;
83 
84 		scratch = per_cpu_ptr(&scomp_scratch, i);
85 
86 		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
87 		if (!mem)
88 			goto error;
89 		scratch->src = mem;
90 		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
91 		if (!mem)
92 			goto error;
93 		scratch->dst = mem;
94 	}
95 	return 0;
96 error:
97 	crypto_scomp_free_scratches();
98 	return -ENOMEM;
99 }
100 
101 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
102 {
103 	int ret = 0;
104 
105 	mutex_lock(&scomp_lock);
106 	if (!scomp_scratch_users++)
107 		ret = crypto_scomp_alloc_scratches();
108 	mutex_unlock(&scomp_lock);
109 
110 	return ret;
111 }
112 
113 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
114 {
115 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
116 	void **tfm_ctx = acomp_tfm_ctx(tfm);
117 	struct crypto_scomp *scomp = *tfm_ctx;
118 	void **ctx = acomp_request_ctx(req);
119 	struct scomp_scratch *scratch;
120 	void *src, *dst;
121 	unsigned int dlen;
122 	int ret;
123 
124 	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
125 		return -EINVAL;
126 
127 	if (req->dst && !req->dlen)
128 		return -EINVAL;
129 
130 	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
131 		req->dlen = SCOMP_SCRATCH_SIZE;
132 
133 	dlen = req->dlen;
134 
135 	scratch = raw_cpu_ptr(&scomp_scratch);
136 	spin_lock(&scratch->lock);
137 
138 	if (sg_nents(req->src) == 1 && !PageHighMem(sg_page(req->src))) {
139 		src = page_to_virt(sg_page(req->src)) + req->src->offset;
140 	} else {
141 		scatterwalk_map_and_copy(scratch->src, req->src, 0,
142 					 req->slen, 0);
143 		src = scratch->src;
144 	}
145 
146 	if (req->dst && sg_nents(req->dst) == 1 && !PageHighMem(sg_page(req->dst)))
147 		dst = page_to_virt(sg_page(req->dst)) + req->dst->offset;
148 	else
149 		dst = scratch->dst;
150 
151 	if (dir)
152 		ret = crypto_scomp_compress(scomp, src, req->slen,
153 					    dst, &req->dlen, *ctx);
154 	else
155 		ret = crypto_scomp_decompress(scomp, src, req->slen,
156 					      dst, &req->dlen, *ctx);
157 	if (!ret) {
158 		if (!req->dst) {
159 			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
160 			if (!req->dst) {
161 				ret = -ENOMEM;
162 				goto out;
163 			}
164 		} else if (req->dlen > dlen) {
165 			ret = -ENOSPC;
166 			goto out;
167 		}
168 		if (dst == scratch->dst) {
169 			scatterwalk_map_and_copy(scratch->dst, req->dst, 0,
170 						 req->dlen, 1);
171 		} else {
172 			int nr_pages = DIV_ROUND_UP(req->dst->offset + req->dlen, PAGE_SIZE);
173 			int i;
174 			struct page *dst_page = sg_page(req->dst);
175 
176 			for (i = 0; i < nr_pages; i++)
177 				flush_dcache_page(dst_page + i);
178 		}
179 	}
180 out:
181 	spin_unlock(&scratch->lock);
182 	return ret;
183 }
184 
185 static int scomp_acomp_compress(struct acomp_req *req)
186 {
187 	return scomp_acomp_comp_decomp(req, 1);
188 }
189 
190 static int scomp_acomp_decompress(struct acomp_req *req)
191 {
192 	return scomp_acomp_comp_decomp(req, 0);
193 }
194 
195 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
196 {
197 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
198 
199 	crypto_free_scomp(*ctx);
200 
201 	mutex_lock(&scomp_lock);
202 	if (!--scomp_scratch_users)
203 		crypto_scomp_free_scratches();
204 	mutex_unlock(&scomp_lock);
205 }
206 
207 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
208 {
209 	struct crypto_alg *calg = tfm->__crt_alg;
210 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
211 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
212 	struct crypto_scomp *scomp;
213 
214 	if (!crypto_mod_get(calg))
215 		return -EAGAIN;
216 
217 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
218 	if (IS_ERR(scomp)) {
219 		crypto_mod_put(calg);
220 		return PTR_ERR(scomp);
221 	}
222 
223 	*ctx = scomp;
224 	tfm->exit = crypto_exit_scomp_ops_async;
225 
226 	crt->compress = scomp_acomp_compress;
227 	crt->decompress = scomp_acomp_decompress;
228 	crt->dst_free = sgl_free;
229 	crt->reqsize = sizeof(void *);
230 
231 	return 0;
232 }
233 
234 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
235 {
236 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
237 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
238 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
239 	struct crypto_scomp *scomp = *tfm_ctx;
240 	void *ctx;
241 
242 	ctx = crypto_scomp_alloc_ctx(scomp);
243 	if (IS_ERR(ctx)) {
244 		kfree(req);
245 		return NULL;
246 	}
247 
248 	*req->__ctx = ctx;
249 
250 	return req;
251 }
252 
253 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
254 {
255 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
256 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
257 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
258 	struct crypto_scomp *scomp = *tfm_ctx;
259 	void *ctx = *req->__ctx;
260 
261 	if (ctx)
262 		crypto_scomp_free_ctx(scomp, ctx);
263 }
264 
265 static const struct crypto_type crypto_scomp_type = {
266 	.extsize = crypto_alg_extsize,
267 	.init_tfm = crypto_scomp_init_tfm,
268 #ifdef CONFIG_PROC_FS
269 	.show = crypto_scomp_show,
270 #endif
271 #if IS_ENABLED(CONFIG_CRYPTO_USER)
272 	.report = crypto_scomp_report,
273 #endif
274 #ifdef CONFIG_CRYPTO_STATS
275 	.report_stat = crypto_acomp_report_stat,
276 #endif
277 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
278 	.maskset = CRYPTO_ALG_TYPE_MASK,
279 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
280 	.tfmsize = offsetof(struct crypto_scomp, base),
281 };
282 
283 int crypto_register_scomp(struct scomp_alg *alg)
284 {
285 	struct crypto_alg *base = &alg->calg.base;
286 
287 	comp_prepare_alg(&alg->calg);
288 
289 	base->cra_type = &crypto_scomp_type;
290 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
291 
292 	return crypto_register_alg(base);
293 }
294 EXPORT_SYMBOL_GPL(crypto_register_scomp);
295 
296 void crypto_unregister_scomp(struct scomp_alg *alg)
297 {
298 	crypto_unregister_alg(&alg->base);
299 }
300 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
301 
302 int crypto_register_scomps(struct scomp_alg *algs, int count)
303 {
304 	int i, ret;
305 
306 	for (i = 0; i < count; i++) {
307 		ret = crypto_register_scomp(&algs[i]);
308 		if (ret)
309 			goto err;
310 	}
311 
312 	return 0;
313 
314 err:
315 	for (--i; i >= 0; --i)
316 		crypto_unregister_scomp(&algs[i]);
317 
318 	return ret;
319 }
320 EXPORT_SYMBOL_GPL(crypto_register_scomps);
321 
322 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
323 {
324 	int i;
325 
326 	for (i = count - 1; i >= 0; --i)
327 		crypto_unregister_scomp(&algs[i]);
328 }
329 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
330 
331 MODULE_LICENSE("GPL");
332 MODULE_DESCRIPTION("Synchronous compression type");
333