xref: /linux/crypto/scompress.c (revision aa23aa55166c2865ac430168c4b9d405cf8c6980)
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 
27 struct scomp_scratch {
28 	spinlock_t	lock;
29 	void		*src;
30 	void		*dst;
31 };
32 
33 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
34 	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
35 };
36 
37 static const struct crypto_type crypto_scomp_type;
38 static int scomp_scratch_users;
39 static DEFINE_MUTEX(scomp_lock);
40 
41 #ifdef CONFIG_NET
42 static 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
54 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
55 {
56 	return -ENOSYS;
57 }
58 #endif
59 
60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
61 	__maybe_unused;
62 
63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
64 {
65 	seq_puts(m, "type         : scomp\n");
66 }
67 
68 static 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 
83 static 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;
103 error:
104 	crypto_scomp_free_scratches();
105 	return -ENOMEM;
106 }
107 
108 static 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 
120 static 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 	int ret;
128 
129 	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
130 		return -EINVAL;
131 
132 	if (req->dst && !req->dlen)
133 		return -EINVAL;
134 
135 	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
136 		req->dlen = SCOMP_SCRATCH_SIZE;
137 
138 	scratch = raw_cpu_ptr(&scomp_scratch);
139 	spin_lock(&scratch->lock);
140 
141 	scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
142 	if (dir)
143 		ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
144 					    scratch->dst, &req->dlen, *ctx);
145 	else
146 		ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
147 					      scratch->dst, &req->dlen, *ctx);
148 	if (!ret) {
149 		if (!req->dst) {
150 			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
151 			if (!req->dst) {
152 				ret = -ENOMEM;
153 				goto out;
154 			}
155 		}
156 		scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
157 					 1);
158 	}
159 out:
160 	spin_unlock(&scratch->lock);
161 	return ret;
162 }
163 
164 static int scomp_acomp_compress(struct acomp_req *req)
165 {
166 	return scomp_acomp_comp_decomp(req, 1);
167 }
168 
169 static int scomp_acomp_decompress(struct acomp_req *req)
170 {
171 	return scomp_acomp_comp_decomp(req, 0);
172 }
173 
174 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
175 {
176 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
177 
178 	crypto_free_scomp(*ctx);
179 
180 	mutex_lock(&scomp_lock);
181 	if (!--scomp_scratch_users)
182 		crypto_scomp_free_scratches();
183 	mutex_unlock(&scomp_lock);
184 }
185 
186 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
187 {
188 	struct crypto_alg *calg = tfm->__crt_alg;
189 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
190 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
191 	struct crypto_scomp *scomp;
192 
193 	if (!crypto_mod_get(calg))
194 		return -EAGAIN;
195 
196 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
197 	if (IS_ERR(scomp)) {
198 		crypto_mod_put(calg);
199 		return PTR_ERR(scomp);
200 	}
201 
202 	*ctx = scomp;
203 	tfm->exit = crypto_exit_scomp_ops_async;
204 
205 	crt->compress = scomp_acomp_compress;
206 	crt->decompress = scomp_acomp_decompress;
207 	crt->dst_free = sgl_free;
208 	crt->reqsize = sizeof(void *);
209 
210 	return 0;
211 }
212 
213 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
214 {
215 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
216 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
217 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
218 	struct crypto_scomp *scomp = *tfm_ctx;
219 	void *ctx;
220 
221 	ctx = crypto_scomp_alloc_ctx(scomp);
222 	if (IS_ERR(ctx)) {
223 		kfree(req);
224 		return NULL;
225 	}
226 
227 	*req->__ctx = ctx;
228 
229 	return req;
230 }
231 
232 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
233 {
234 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
235 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
236 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
237 	struct crypto_scomp *scomp = *tfm_ctx;
238 	void *ctx = *req->__ctx;
239 
240 	if (ctx)
241 		crypto_scomp_free_ctx(scomp, ctx);
242 }
243 
244 static const struct crypto_type crypto_scomp_type = {
245 	.extsize = crypto_alg_extsize,
246 	.init_tfm = crypto_scomp_init_tfm,
247 #ifdef CONFIG_PROC_FS
248 	.show = crypto_scomp_show,
249 #endif
250 	.report = crypto_scomp_report,
251 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
252 	.maskset = CRYPTO_ALG_TYPE_MASK,
253 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
254 	.tfmsize = offsetof(struct crypto_scomp, base),
255 };
256 
257 int crypto_register_scomp(struct scomp_alg *alg)
258 {
259 	struct crypto_alg *base = &alg->base;
260 
261 	base->cra_type = &crypto_scomp_type;
262 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
263 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
264 
265 	return crypto_register_alg(base);
266 }
267 EXPORT_SYMBOL_GPL(crypto_register_scomp);
268 
269 int crypto_unregister_scomp(struct scomp_alg *alg)
270 {
271 	return crypto_unregister_alg(&alg->base);
272 }
273 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
274 
275 int crypto_register_scomps(struct scomp_alg *algs, int count)
276 {
277 	int i, ret;
278 
279 	for (i = 0; i < count; i++) {
280 		ret = crypto_register_scomp(&algs[i]);
281 		if (ret)
282 			goto err;
283 	}
284 
285 	return 0;
286 
287 err:
288 	for (--i; i >= 0; --i)
289 		crypto_unregister_scomp(&algs[i]);
290 
291 	return ret;
292 }
293 EXPORT_SYMBOL_GPL(crypto_register_scomps);
294 
295 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
296 {
297 	int i;
298 
299 	for (i = count - 1; i >= 0; --i)
300 		crypto_unregister_scomp(&algs[i]);
301 }
302 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
303 
304 MODULE_LICENSE("GPL");
305 MODULE_DESCRIPTION("Synchronous compression type");
306