xref: /openbmc/linux/crypto/scompress.c (revision cb1aaebe)
1 /*
2  * Synchronous Compression operations
3  *
4  * Copyright 2015 LG Electronics Inc.
5  * Copyright (c) 2016, Intel Corporation
6  * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the Free
10  * Software Foundation; either version 2 of the License, or (at your option)
11  * any later version.
12  *
13  */
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/seq_file.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/crypto.h>
21 #include <linux/compiler.h>
22 #include <linux/vmalloc.h>
23 #include <crypto/algapi.h>
24 #include <linux/cryptouser.h>
25 #include <net/netlink.h>
26 #include <linux/scatterlist.h>
27 #include <crypto/scatterwalk.h>
28 #include <crypto/internal/acompress.h>
29 #include <crypto/internal/scompress.h>
30 #include "internal.h"
31 
32 struct scomp_scratch {
33 	spinlock_t	lock;
34 	void		*src;
35 	void		*dst;
36 };
37 
38 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
39 	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
40 };
41 
42 static const struct crypto_type crypto_scomp_type;
43 static int scomp_scratch_users;
44 static DEFINE_MUTEX(scomp_lock);
45 
46 #ifdef CONFIG_NET
47 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
48 {
49 	struct crypto_report_comp rscomp;
50 
51 	memset(&rscomp, 0, sizeof(rscomp));
52 
53 	strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
54 
55 	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
56 		       sizeof(rscomp), &rscomp);
57 }
58 #else
59 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
60 {
61 	return -ENOSYS;
62 }
63 #endif
64 
65 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
66 	__maybe_unused;
67 
68 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
69 {
70 	seq_puts(m, "type         : scomp\n");
71 }
72 
73 static void crypto_scomp_free_scratches(void)
74 {
75 	struct scomp_scratch *scratch;
76 	int i;
77 
78 	for_each_possible_cpu(i) {
79 		scratch = per_cpu_ptr(&scomp_scratch, i);
80 
81 		vfree(scratch->src);
82 		vfree(scratch->dst);
83 		scratch->src = NULL;
84 		scratch->dst = NULL;
85 	}
86 }
87 
88 static int crypto_scomp_alloc_scratches(void)
89 {
90 	struct scomp_scratch *scratch;
91 	int i;
92 
93 	for_each_possible_cpu(i) {
94 		void *mem;
95 
96 		scratch = per_cpu_ptr(&scomp_scratch, i);
97 
98 		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
99 		if (!mem)
100 			goto error;
101 		scratch->src = mem;
102 		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
103 		if (!mem)
104 			goto error;
105 		scratch->dst = mem;
106 	}
107 	return 0;
108 error:
109 	crypto_scomp_free_scratches();
110 	return -ENOMEM;
111 }
112 
113 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
114 {
115 	int ret = 0;
116 
117 	mutex_lock(&scomp_lock);
118 	if (!scomp_scratch_users++)
119 		ret = crypto_scomp_alloc_scratches();
120 	mutex_unlock(&scomp_lock);
121 
122 	return ret;
123 }
124 
125 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
126 {
127 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
128 	void **tfm_ctx = acomp_tfm_ctx(tfm);
129 	struct crypto_scomp *scomp = *tfm_ctx;
130 	void **ctx = acomp_request_ctx(req);
131 	struct scomp_scratch *scratch;
132 	int ret;
133 
134 	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
135 		return -EINVAL;
136 
137 	if (req->dst && !req->dlen)
138 		return -EINVAL;
139 
140 	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
141 		req->dlen = SCOMP_SCRATCH_SIZE;
142 
143 	scratch = raw_cpu_ptr(&scomp_scratch);
144 	spin_lock(&scratch->lock);
145 
146 	scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
147 	if (dir)
148 		ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
149 					    scratch->dst, &req->dlen, *ctx);
150 	else
151 		ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
152 					      scratch->dst, &req->dlen, *ctx);
153 	if (!ret) {
154 		if (!req->dst) {
155 			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
156 			if (!req->dst) {
157 				ret = -ENOMEM;
158 				goto out;
159 			}
160 		}
161 		scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
162 					 1);
163 	}
164 out:
165 	spin_unlock(&scratch->lock);
166 	return ret;
167 }
168 
169 static int scomp_acomp_compress(struct acomp_req *req)
170 {
171 	return scomp_acomp_comp_decomp(req, 1);
172 }
173 
174 static int scomp_acomp_decompress(struct acomp_req *req)
175 {
176 	return scomp_acomp_comp_decomp(req, 0);
177 }
178 
179 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
180 {
181 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
182 
183 	crypto_free_scomp(*ctx);
184 
185 	mutex_lock(&scomp_lock);
186 	if (!--scomp_scratch_users)
187 		crypto_scomp_free_scratches();
188 	mutex_unlock(&scomp_lock);
189 }
190 
191 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
192 {
193 	struct crypto_alg *calg = tfm->__crt_alg;
194 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
195 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
196 	struct crypto_scomp *scomp;
197 
198 	if (!crypto_mod_get(calg))
199 		return -EAGAIN;
200 
201 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
202 	if (IS_ERR(scomp)) {
203 		crypto_mod_put(calg);
204 		return PTR_ERR(scomp);
205 	}
206 
207 	*ctx = scomp;
208 	tfm->exit = crypto_exit_scomp_ops_async;
209 
210 	crt->compress = scomp_acomp_compress;
211 	crt->decompress = scomp_acomp_decompress;
212 	crt->dst_free = sgl_free;
213 	crt->reqsize = sizeof(void *);
214 
215 	return 0;
216 }
217 
218 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
219 {
220 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
221 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
222 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
223 	struct crypto_scomp *scomp = *tfm_ctx;
224 	void *ctx;
225 
226 	ctx = crypto_scomp_alloc_ctx(scomp);
227 	if (IS_ERR(ctx)) {
228 		kfree(req);
229 		return NULL;
230 	}
231 
232 	*req->__ctx = ctx;
233 
234 	return req;
235 }
236 
237 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
238 {
239 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
240 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
241 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
242 	struct crypto_scomp *scomp = *tfm_ctx;
243 	void *ctx = *req->__ctx;
244 
245 	if (ctx)
246 		crypto_scomp_free_ctx(scomp, ctx);
247 }
248 
249 static const struct crypto_type crypto_scomp_type = {
250 	.extsize = crypto_alg_extsize,
251 	.init_tfm = crypto_scomp_init_tfm,
252 #ifdef CONFIG_PROC_FS
253 	.show = crypto_scomp_show,
254 #endif
255 	.report = crypto_scomp_report,
256 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
257 	.maskset = CRYPTO_ALG_TYPE_MASK,
258 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
259 	.tfmsize = offsetof(struct crypto_scomp, base),
260 };
261 
262 int crypto_register_scomp(struct scomp_alg *alg)
263 {
264 	struct crypto_alg *base = &alg->base;
265 
266 	base->cra_type = &crypto_scomp_type;
267 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
268 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
269 
270 	return crypto_register_alg(base);
271 }
272 EXPORT_SYMBOL_GPL(crypto_register_scomp);
273 
274 int crypto_unregister_scomp(struct scomp_alg *alg)
275 {
276 	return crypto_unregister_alg(&alg->base);
277 }
278 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
279 
280 int crypto_register_scomps(struct scomp_alg *algs, int count)
281 {
282 	int i, ret;
283 
284 	for (i = 0; i < count; i++) {
285 		ret = crypto_register_scomp(&algs[i]);
286 		if (ret)
287 			goto err;
288 	}
289 
290 	return 0;
291 
292 err:
293 	for (--i; i >= 0; --i)
294 		crypto_unregister_scomp(&algs[i]);
295 
296 	return ret;
297 }
298 EXPORT_SYMBOL_GPL(crypto_register_scomps);
299 
300 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
301 {
302 	int i;
303 
304 	for (i = count - 1; i >= 0; --i)
305 		crypto_unregister_scomp(&algs[i]);
306 }
307 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
308 
309 MODULE_LICENSE("GPL");
310 MODULE_DESCRIPTION("Synchronous compression type");
311