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 static const struct crypto_type crypto_scomp_type;
33 static void * __percpu *scomp_src_scratches;
34 static void * __percpu *scomp_dst_scratches;
35 static int scomp_scratch_users;
36 static DEFINE_MUTEX(scomp_lock);
37 
38 #ifdef CONFIG_NET
crypto_scomp_report(struct sk_buff * skb,struct crypto_alg * alg)39 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
40 {
41 	struct crypto_report_comp rscomp;
42 
43 	strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
44 
45 	if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
46 		    sizeof(struct crypto_report_comp), &rscomp))
47 		goto nla_put_failure;
48 	return 0;
49 
50 nla_put_failure:
51 	return -EMSGSIZE;
52 }
53 #else
crypto_scomp_report(struct sk_buff * skb,struct crypto_alg * alg)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 
crypto_scomp_show(struct seq_file * m,struct crypto_alg * alg)63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
64 {
65 	seq_puts(m, "type         : scomp\n");
66 }
67 
crypto_scomp_free_scratches(void * __percpu * scratches)68 static void crypto_scomp_free_scratches(void * __percpu *scratches)
69 {
70 	int i;
71 
72 	if (!scratches)
73 		return;
74 
75 	for_each_possible_cpu(i)
76 		vfree(*per_cpu_ptr(scratches, i));
77 
78 	free_percpu(scratches);
79 }
80 
crypto_scomp_alloc_scratches(void)81 static void * __percpu *crypto_scomp_alloc_scratches(void)
82 {
83 	void * __percpu *scratches;
84 	int i;
85 
86 	scratches = alloc_percpu(void *);
87 	if (!scratches)
88 		return NULL;
89 
90 	for_each_possible_cpu(i) {
91 		void *scratch;
92 
93 		scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
94 		if (!scratch)
95 			goto error;
96 		*per_cpu_ptr(scratches, i) = scratch;
97 	}
98 
99 	return scratches;
100 
101 error:
102 	crypto_scomp_free_scratches(scratches);
103 	return NULL;
104 }
105 
crypto_scomp_free_all_scratches(void)106 static void crypto_scomp_free_all_scratches(void)
107 {
108 	if (!--scomp_scratch_users) {
109 		crypto_scomp_free_scratches(scomp_src_scratches);
110 		crypto_scomp_free_scratches(scomp_dst_scratches);
111 		scomp_src_scratches = NULL;
112 		scomp_dst_scratches = NULL;
113 	}
114 }
115 
crypto_scomp_alloc_all_scratches(void)116 static int crypto_scomp_alloc_all_scratches(void)
117 {
118 	if (!scomp_scratch_users++) {
119 		scomp_src_scratches = crypto_scomp_alloc_scratches();
120 		if (!scomp_src_scratches)
121 			return -ENOMEM;
122 		scomp_dst_scratches = crypto_scomp_alloc_scratches();
123 		if (!scomp_dst_scratches) {
124 			crypto_scomp_free_scratches(scomp_src_scratches);
125 			scomp_src_scratches = NULL;
126 			return -ENOMEM;
127 		}
128 	}
129 	return 0;
130 }
131 
crypto_scomp_init_tfm(struct crypto_tfm * tfm)132 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
133 {
134 	int ret;
135 
136 	mutex_lock(&scomp_lock);
137 	ret = crypto_scomp_alloc_all_scratches();
138 	mutex_unlock(&scomp_lock);
139 
140 	return ret;
141 }
142 
scomp_acomp_comp_decomp(struct acomp_req * req,int dir)143 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
144 {
145 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
146 	void **tfm_ctx = acomp_tfm_ctx(tfm);
147 	struct crypto_scomp *scomp = *tfm_ctx;
148 	void **ctx = acomp_request_ctx(req);
149 	const int cpu = get_cpu();
150 	u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
151 	u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
152 	int ret;
153 
154 	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
155 		ret = -EINVAL;
156 		goto out;
157 	}
158 
159 	if (req->dst && !req->dlen) {
160 		ret = -EINVAL;
161 		goto out;
162 	}
163 
164 	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
165 		req->dlen = SCOMP_SCRATCH_SIZE;
166 
167 	scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
168 	if (dir)
169 		ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
170 					    scratch_dst, &req->dlen, *ctx);
171 	else
172 		ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
173 					      scratch_dst, &req->dlen, *ctx);
174 	if (!ret) {
175 		if (!req->dst) {
176 			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
177 			if (!req->dst)
178 				goto out;
179 		}
180 		scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
181 					 1);
182 	}
183 out:
184 	put_cpu();
185 	return ret;
186 }
187 
scomp_acomp_compress(struct acomp_req * req)188 static int scomp_acomp_compress(struct acomp_req *req)
189 {
190 	return scomp_acomp_comp_decomp(req, 1);
191 }
192 
scomp_acomp_decompress(struct acomp_req * req)193 static int scomp_acomp_decompress(struct acomp_req *req)
194 {
195 	return scomp_acomp_comp_decomp(req, 0);
196 }
197 
crypto_exit_scomp_ops_async(struct crypto_tfm * tfm)198 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
199 {
200 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
201 
202 	crypto_free_scomp(*ctx);
203 
204 	mutex_lock(&scomp_lock);
205 	crypto_scomp_free_all_scratches();
206 	mutex_unlock(&scomp_lock);
207 }
208 
crypto_init_scomp_ops_async(struct crypto_tfm * tfm)209 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
210 {
211 	struct crypto_alg *calg = tfm->__crt_alg;
212 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
213 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
214 	struct crypto_scomp *scomp;
215 
216 	if (!crypto_mod_get(calg))
217 		return -EAGAIN;
218 
219 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
220 	if (IS_ERR(scomp)) {
221 		crypto_mod_put(calg);
222 		return PTR_ERR(scomp);
223 	}
224 
225 	*ctx = scomp;
226 	tfm->exit = crypto_exit_scomp_ops_async;
227 
228 	crt->compress = scomp_acomp_compress;
229 	crt->decompress = scomp_acomp_decompress;
230 	crt->dst_free = sgl_free;
231 	crt->reqsize = sizeof(void *);
232 
233 	return 0;
234 }
235 
crypto_acomp_scomp_alloc_ctx(struct acomp_req * req)236 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
237 {
238 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
239 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
240 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
241 	struct crypto_scomp *scomp = *tfm_ctx;
242 	void *ctx;
243 
244 	ctx = crypto_scomp_alloc_ctx(scomp);
245 	if (IS_ERR(ctx)) {
246 		kfree(req);
247 		return NULL;
248 	}
249 
250 	*req->__ctx = ctx;
251 
252 	return req;
253 }
254 
crypto_acomp_scomp_free_ctx(struct acomp_req * req)255 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
256 {
257 	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
258 	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
259 	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
260 	struct crypto_scomp *scomp = *tfm_ctx;
261 	void *ctx = *req->__ctx;
262 
263 	if (ctx)
264 		crypto_scomp_free_ctx(scomp, ctx);
265 }
266 
267 static const struct crypto_type crypto_scomp_type = {
268 	.extsize = crypto_alg_extsize,
269 	.init_tfm = crypto_scomp_init_tfm,
270 #ifdef CONFIG_PROC_FS
271 	.show = crypto_scomp_show,
272 #endif
273 	.report = crypto_scomp_report,
274 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
275 	.maskset = CRYPTO_ALG_TYPE_MASK,
276 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
277 	.tfmsize = offsetof(struct crypto_scomp, base),
278 };
279 
crypto_register_scomp(struct scomp_alg * alg)280 int crypto_register_scomp(struct scomp_alg *alg)
281 {
282 	struct crypto_alg *base = &alg->base;
283 
284 	base->cra_type = &crypto_scomp_type;
285 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
286 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
287 
288 	return crypto_register_alg(base);
289 }
290 EXPORT_SYMBOL_GPL(crypto_register_scomp);
291 
crypto_unregister_scomp(struct scomp_alg * alg)292 int crypto_unregister_scomp(struct scomp_alg *alg)
293 {
294 	return crypto_unregister_alg(&alg->base);
295 }
296 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
297 
crypto_register_scomps(struct scomp_alg * algs,int count)298 int crypto_register_scomps(struct scomp_alg *algs, int count)
299 {
300 	int i, ret;
301 
302 	for (i = 0; i < count; i++) {
303 		ret = crypto_register_scomp(&algs[i]);
304 		if (ret)
305 			goto err;
306 	}
307 
308 	return 0;
309 
310 err:
311 	for (--i; i >= 0; --i)
312 		crypto_unregister_scomp(&algs[i]);
313 
314 	return ret;
315 }
316 EXPORT_SYMBOL_GPL(crypto_register_scomps);
317 
crypto_unregister_scomps(struct scomp_alg * algs,int count)318 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
319 {
320 	int i;
321 
322 	for (i = count - 1; i >= 0; --i)
323 		crypto_unregister_scomp(&algs[i]);
324 }
325 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
326 
327 MODULE_LICENSE("GPL");
328 MODULE_DESCRIPTION("Synchronous compression type");
329