xref: /linux/crypto/scompress.c (revision 31ca5d49264ba6197aa48a926f6a035ed08b3715)
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 	int ret;
121 
122 	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
123 		return -EINVAL;
124 
125 	if (req->dst && !req->dlen)
126 		return -EINVAL;
127 
128 	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
129 		req->dlen = SCOMP_SCRATCH_SIZE;
130 
131 	scratch = raw_cpu_ptr(&scomp_scratch);
132 	spin_lock(&scratch->lock);
133 
134 	scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
135 	if (dir)
136 		ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
137 					    scratch->dst, &req->dlen, *ctx);
138 	else
139 		ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
140 					      scratch->dst, &req->dlen, *ctx);
141 	if (!ret) {
142 		if (!req->dst) {
143 			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
144 			if (!req->dst) {
145 				ret = -ENOMEM;
146 				goto out;
147 			}
148 		}
149 		scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
150 					 1);
151 	}
152 out:
153 	spin_unlock(&scratch->lock);
154 	return ret;
155 }
156 
157 static int scomp_acomp_compress(struct acomp_req *req)
158 {
159 	return scomp_acomp_comp_decomp(req, 1);
160 }
161 
162 static int scomp_acomp_decompress(struct acomp_req *req)
163 {
164 	return scomp_acomp_comp_decomp(req, 0);
165 }
166 
167 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
168 {
169 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
170 
171 	crypto_free_scomp(*ctx);
172 
173 	mutex_lock(&scomp_lock);
174 	if (!--scomp_scratch_users)
175 		crypto_scomp_free_scratches();
176 	mutex_unlock(&scomp_lock);
177 }
178 
179 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
180 {
181 	struct crypto_alg *calg = tfm->__crt_alg;
182 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
183 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
184 	struct crypto_scomp *scomp;
185 
186 	if (!crypto_mod_get(calg))
187 		return -EAGAIN;
188 
189 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
190 	if (IS_ERR(scomp)) {
191 		crypto_mod_put(calg);
192 		return PTR_ERR(scomp);
193 	}
194 
195 	*ctx = scomp;
196 	tfm->exit = crypto_exit_scomp_ops_async;
197 
198 	crt->compress = scomp_acomp_compress;
199 	crt->decompress = scomp_acomp_decompress;
200 	crt->dst_free = sgl_free;
201 	crt->reqsize = sizeof(void *);
202 
203 	return 0;
204 }
205 
206 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
207 {
208 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
209 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
210 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
211 	struct crypto_scomp *scomp = *tfm_ctx;
212 	void *ctx;
213 
214 	ctx = crypto_scomp_alloc_ctx(scomp);
215 	if (IS_ERR(ctx)) {
216 		kfree(req);
217 		return NULL;
218 	}
219 
220 	*req->__ctx = ctx;
221 
222 	return req;
223 }
224 
225 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
226 {
227 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
228 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
229 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
230 	struct crypto_scomp *scomp = *tfm_ctx;
231 	void *ctx = *req->__ctx;
232 
233 	if (ctx)
234 		crypto_scomp_free_ctx(scomp, ctx);
235 }
236 
237 static const struct crypto_type crypto_scomp_type = {
238 	.extsize = crypto_alg_extsize,
239 	.init_tfm = crypto_scomp_init_tfm,
240 #ifdef CONFIG_PROC_FS
241 	.show = crypto_scomp_show,
242 #endif
243 #if IS_ENABLED(CONFIG_CRYPTO_USER)
244 	.report = crypto_scomp_report,
245 #endif
246 #ifdef CONFIG_CRYPTO_STATS
247 	.report_stat = crypto_acomp_report_stat,
248 #endif
249 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
250 	.maskset = CRYPTO_ALG_TYPE_MASK,
251 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
252 	.tfmsize = offsetof(struct crypto_scomp, base),
253 };
254 
255 int crypto_register_scomp(struct scomp_alg *alg)
256 {
257 	struct crypto_alg *base = &alg->calg.base;
258 
259 	comp_prepare_alg(&alg->calg);
260 
261 	base->cra_type = &crypto_scomp_type;
262 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
263 
264 	return crypto_register_alg(base);
265 }
266 EXPORT_SYMBOL_GPL(crypto_register_scomp);
267 
268 void crypto_unregister_scomp(struct scomp_alg *alg)
269 {
270 	crypto_unregister_alg(&alg->base);
271 }
272 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
273 
274 int crypto_register_scomps(struct scomp_alg *algs, int count)
275 {
276 	int i, ret;
277 
278 	for (i = 0; i < count; i++) {
279 		ret = crypto_register_scomp(&algs[i]);
280 		if (ret)
281 			goto err;
282 	}
283 
284 	return 0;
285 
286 err:
287 	for (--i; i >= 0; --i)
288 		crypto_unregister_scomp(&algs[i]);
289 
290 	return ret;
291 }
292 EXPORT_SYMBOL_GPL(crypto_register_scomps);
293 
294 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
295 {
296 	int i;
297 
298 	for (i = count - 1; i >= 0; --i)
299 		crypto_unregister_scomp(&algs[i]);
300 }
301 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
302 
303 MODULE_LICENSE("GPL");
304 MODULE_DESCRIPTION("Synchronous compression type");
305