xref: /openbmc/linux/crypto/pcrypt.c (revision 59bd9ded)
1 /*
2  * pcrypt - Parallel crypto wrapper.
3  *
4  * Copyright (C) 2009 secunet Security Networks AG
5  * Copyright (C) 2009 Steffen Klassert <steffen.klassert@secunet.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <crypto/algapi.h>
22 #include <crypto/internal/aead.h>
23 #include <linux/atomic.h>
24 #include <linux/err.h>
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/notifier.h>
29 #include <linux/kobject.h>
30 #include <linux/cpu.h>
31 #include <crypto/pcrypt.h>
32 
33 struct padata_pcrypt {
34 	struct padata_instance *pinst;
35 	struct workqueue_struct *wq;
36 
37 	/*
38 	 * Cpumask for callback CPUs. It should be
39 	 * equal to serial cpumask of corresponding padata instance,
40 	 * so it is updated when padata notifies us about serial
41 	 * cpumask change.
42 	 *
43 	 * cb_cpumask is protected by RCU. This fact prevents us from
44 	 * using cpumask_var_t directly because the actual type of
45 	 * cpumsak_var_t depends on kernel configuration(particularly on
46 	 * CONFIG_CPUMASK_OFFSTACK macro). Depending on the configuration
47 	 * cpumask_var_t may be either a pointer to the struct cpumask
48 	 * or a variable allocated on the stack. Thus we can not safely use
49 	 * cpumask_var_t with RCU operations such as rcu_assign_pointer or
50 	 * rcu_dereference. So cpumask_var_t is wrapped with struct
51 	 * pcrypt_cpumask which makes possible to use it with RCU.
52 	 */
53 	struct pcrypt_cpumask {
54 		cpumask_var_t mask;
55 	} *cb_cpumask;
56 	struct notifier_block nblock;
57 };
58 
59 static struct padata_pcrypt pencrypt;
60 static struct padata_pcrypt pdecrypt;
61 static struct kset           *pcrypt_kset;
62 
63 struct pcrypt_instance_ctx {
64 	struct crypto_aead_spawn spawn;
65 	atomic_t tfm_count;
66 };
67 
68 struct pcrypt_aead_ctx {
69 	struct crypto_aead *child;
70 	unsigned int cb_cpu;
71 };
72 
73 static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
74 			      struct padata_pcrypt *pcrypt)
75 {
76 	unsigned int cpu_index, cpu, i;
77 	struct pcrypt_cpumask *cpumask;
78 
79 	cpu = *cb_cpu;
80 
81 	rcu_read_lock_bh();
82 	cpumask = rcu_dereference_bh(pcrypt->cb_cpumask);
83 	if (cpumask_test_cpu(cpu, cpumask->mask))
84 			goto out;
85 
86 	if (!cpumask_weight(cpumask->mask))
87 			goto out;
88 
89 	cpu_index = cpu % cpumask_weight(cpumask->mask);
90 
91 	cpu = cpumask_first(cpumask->mask);
92 	for (i = 0; i < cpu_index; i++)
93 		cpu = cpumask_next(cpu, cpumask->mask);
94 
95 	*cb_cpu = cpu;
96 
97 out:
98 	rcu_read_unlock_bh();
99 	return padata_do_parallel(pcrypt->pinst, padata, cpu);
100 }
101 
102 static int pcrypt_aead_setkey(struct crypto_aead *parent,
103 			      const u8 *key, unsigned int keylen)
104 {
105 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
106 
107 	return crypto_aead_setkey(ctx->child, key, keylen);
108 }
109 
110 static int pcrypt_aead_setauthsize(struct crypto_aead *parent,
111 				   unsigned int authsize)
112 {
113 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
114 
115 	return crypto_aead_setauthsize(ctx->child, authsize);
116 }
117 
118 static void pcrypt_aead_serial(struct padata_priv *padata)
119 {
120 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
121 	struct aead_request *req = pcrypt_request_ctx(preq);
122 
123 	aead_request_complete(req->base.data, padata->info);
124 }
125 
126 static void pcrypt_aead_done(struct crypto_async_request *areq, int err)
127 {
128 	struct aead_request *req = areq->data;
129 	struct pcrypt_request *preq = aead_request_ctx(req);
130 	struct padata_priv *padata = pcrypt_request_padata(preq);
131 
132 	padata->info = err;
133 	req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
134 
135 	padata_do_serial(padata);
136 }
137 
138 static void pcrypt_aead_enc(struct padata_priv *padata)
139 {
140 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
141 	struct aead_request *req = pcrypt_request_ctx(preq);
142 
143 	padata->info = crypto_aead_encrypt(req);
144 
145 	if (padata->info == -EINPROGRESS)
146 		return;
147 
148 	padata_do_serial(padata);
149 }
150 
151 static int pcrypt_aead_encrypt(struct aead_request *req)
152 {
153 	int err;
154 	struct pcrypt_request *preq = aead_request_ctx(req);
155 	struct aead_request *creq = pcrypt_request_ctx(preq);
156 	struct padata_priv *padata = pcrypt_request_padata(preq);
157 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
158 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
159 	u32 flags = aead_request_flags(req);
160 
161 	memset(padata, 0, sizeof(struct padata_priv));
162 
163 	padata->parallel = pcrypt_aead_enc;
164 	padata->serial = pcrypt_aead_serial;
165 
166 	aead_request_set_tfm(creq, ctx->child);
167 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
168 				  pcrypt_aead_done, req);
169 	aead_request_set_crypt(creq, req->src, req->dst,
170 			       req->cryptlen, req->iv);
171 	aead_request_set_ad(creq, req->assoclen);
172 
173 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
174 	if (!err)
175 		return -EINPROGRESS;
176 
177 	return err;
178 }
179 
180 static void pcrypt_aead_dec(struct padata_priv *padata)
181 {
182 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
183 	struct aead_request *req = pcrypt_request_ctx(preq);
184 
185 	padata->info = crypto_aead_decrypt(req);
186 
187 	if (padata->info == -EINPROGRESS)
188 		return;
189 
190 	padata_do_serial(padata);
191 }
192 
193 static int pcrypt_aead_decrypt(struct aead_request *req)
194 {
195 	int err;
196 	struct pcrypt_request *preq = aead_request_ctx(req);
197 	struct aead_request *creq = pcrypt_request_ctx(preq);
198 	struct padata_priv *padata = pcrypt_request_padata(preq);
199 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
200 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
201 	u32 flags = aead_request_flags(req);
202 
203 	memset(padata, 0, sizeof(struct padata_priv));
204 
205 	padata->parallel = pcrypt_aead_dec;
206 	padata->serial = pcrypt_aead_serial;
207 
208 	aead_request_set_tfm(creq, ctx->child);
209 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
210 				  pcrypt_aead_done, req);
211 	aead_request_set_crypt(creq, req->src, req->dst,
212 			       req->cryptlen, req->iv);
213 	aead_request_set_ad(creq, req->assoclen);
214 
215 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
216 	if (!err)
217 		return -EINPROGRESS;
218 
219 	return err;
220 }
221 
222 static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
223 {
224 	int cpu, cpu_index;
225 	struct aead_instance *inst = aead_alg_instance(tfm);
226 	struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
227 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
228 	struct crypto_aead *cipher;
229 
230 	cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
231 		    cpumask_weight(cpu_online_mask);
232 
233 	ctx->cb_cpu = cpumask_first(cpu_online_mask);
234 	for (cpu = 0; cpu < cpu_index; cpu++)
235 		ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
236 
237 	cipher = crypto_spawn_aead(&ictx->spawn);
238 
239 	if (IS_ERR(cipher))
240 		return PTR_ERR(cipher);
241 
242 	ctx->child = cipher;
243 	crypto_aead_set_reqsize(tfm, sizeof(struct pcrypt_request) +
244 				     sizeof(struct aead_request) +
245 				     crypto_aead_reqsize(cipher));
246 
247 	return 0;
248 }
249 
250 static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm)
251 {
252 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
253 
254 	crypto_free_aead(ctx->child);
255 }
256 
257 static void pcrypt_free(struct aead_instance *inst)
258 {
259 	struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst);
260 
261 	crypto_drop_aead(&ctx->spawn);
262 	kfree(inst);
263 }
264 
265 static int pcrypt_init_instance(struct crypto_instance *inst,
266 				struct crypto_alg *alg)
267 {
268 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
269 		     "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
270 		return -ENAMETOOLONG;
271 
272 	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
273 
274 	inst->alg.cra_priority = alg->cra_priority + 100;
275 	inst->alg.cra_blocksize = alg->cra_blocksize;
276 	inst->alg.cra_alignmask = alg->cra_alignmask;
277 
278 	return 0;
279 }
280 
281 static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
282 			      u32 type, u32 mask)
283 {
284 	struct pcrypt_instance_ctx *ctx;
285 	struct crypto_attr_type *algt;
286 	struct aead_instance *inst;
287 	struct aead_alg *alg;
288 	const char *name;
289 	int err;
290 
291 	algt = crypto_get_attr_type(tb);
292 	if (IS_ERR(algt))
293 		return PTR_ERR(algt);
294 
295 	name = crypto_attr_alg_name(tb[1]);
296 	if (IS_ERR(name))
297 		return PTR_ERR(name);
298 
299 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
300 	if (!inst)
301 		return -ENOMEM;
302 
303 	ctx = aead_instance_ctx(inst);
304 	crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
305 
306 	err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
307 	if (err)
308 		goto out_free_inst;
309 
310 	alg = crypto_spawn_aead_alg(&ctx->spawn);
311 	err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
312 	if (err)
313 		goto out_drop_aead;
314 
315 	inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC;
316 
317 	inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
318 	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
319 
320 	inst->alg.base.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
321 
322 	inst->alg.init = pcrypt_aead_init_tfm;
323 	inst->alg.exit = pcrypt_aead_exit_tfm;
324 
325 	inst->alg.setkey = pcrypt_aead_setkey;
326 	inst->alg.setauthsize = pcrypt_aead_setauthsize;
327 	inst->alg.encrypt = pcrypt_aead_encrypt;
328 	inst->alg.decrypt = pcrypt_aead_decrypt;
329 
330 	inst->free = pcrypt_free;
331 
332 	err = aead_register_instance(tmpl, inst);
333 	if (err)
334 		goto out_drop_aead;
335 
336 out:
337 	return err;
338 
339 out_drop_aead:
340 	crypto_drop_aead(&ctx->spawn);
341 out_free_inst:
342 	kfree(inst);
343 	goto out;
344 }
345 
346 static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb)
347 {
348 	struct crypto_attr_type *algt;
349 
350 	algt = crypto_get_attr_type(tb);
351 	if (IS_ERR(algt))
352 		return PTR_ERR(algt);
353 
354 	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
355 	case CRYPTO_ALG_TYPE_AEAD:
356 		return pcrypt_create_aead(tmpl, tb, algt->type, algt->mask);
357 	}
358 
359 	return -EINVAL;
360 }
361 
362 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
363 					unsigned long val, void *data)
364 {
365 	struct padata_pcrypt *pcrypt;
366 	struct pcrypt_cpumask *new_mask, *old_mask;
367 	struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
368 
369 	if (!(val & PADATA_CPU_SERIAL))
370 		return 0;
371 
372 	pcrypt = container_of(self, struct padata_pcrypt, nblock);
373 	new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
374 	if (!new_mask)
375 		return -ENOMEM;
376 	if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
377 		kfree(new_mask);
378 		return -ENOMEM;
379 	}
380 
381 	old_mask = pcrypt->cb_cpumask;
382 
383 	cpumask_copy(new_mask->mask, cpumask->cbcpu);
384 	rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
385 	synchronize_rcu();
386 
387 	free_cpumask_var(old_mask->mask);
388 	kfree(old_mask);
389 	return 0;
390 }
391 
392 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
393 {
394 	int ret;
395 
396 	pinst->kobj.kset = pcrypt_kset;
397 	ret = kobject_add(&pinst->kobj, NULL, "%s", name);
398 	if (!ret)
399 		kobject_uevent(&pinst->kobj, KOBJ_ADD);
400 
401 	return ret;
402 }
403 
404 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
405 			      const char *name)
406 {
407 	int ret = -ENOMEM;
408 	struct pcrypt_cpumask *mask;
409 
410 	get_online_cpus();
411 
412 	pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
413 				     1, name);
414 	if (!pcrypt->wq)
415 		goto err;
416 
417 	pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
418 	if (!pcrypt->pinst)
419 		goto err_destroy_workqueue;
420 
421 	mask = kmalloc(sizeof(*mask), GFP_KERNEL);
422 	if (!mask)
423 		goto err_free_padata;
424 	if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
425 		kfree(mask);
426 		goto err_free_padata;
427 	}
428 
429 	cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
430 	rcu_assign_pointer(pcrypt->cb_cpumask, mask);
431 
432 	pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
433 	ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
434 	if (ret)
435 		goto err_free_cpumask;
436 
437 	ret = pcrypt_sysfs_add(pcrypt->pinst, name);
438 	if (ret)
439 		goto err_unregister_notifier;
440 
441 	put_online_cpus();
442 
443 	return ret;
444 
445 err_unregister_notifier:
446 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
447 err_free_cpumask:
448 	free_cpumask_var(mask->mask);
449 	kfree(mask);
450 err_free_padata:
451 	padata_free(pcrypt->pinst);
452 err_destroy_workqueue:
453 	destroy_workqueue(pcrypt->wq);
454 err:
455 	put_online_cpus();
456 
457 	return ret;
458 }
459 
460 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
461 {
462 	free_cpumask_var(pcrypt->cb_cpumask->mask);
463 	kfree(pcrypt->cb_cpumask);
464 
465 	padata_stop(pcrypt->pinst);
466 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
467 	destroy_workqueue(pcrypt->wq);
468 	padata_free(pcrypt->pinst);
469 }
470 
471 static struct crypto_template pcrypt_tmpl = {
472 	.name = "pcrypt",
473 	.create = pcrypt_create,
474 	.module = THIS_MODULE,
475 };
476 
477 static int __init pcrypt_init(void)
478 {
479 	int err = -ENOMEM;
480 
481 	pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
482 	if (!pcrypt_kset)
483 		goto err;
484 
485 	err = pcrypt_init_padata(&pencrypt, "pencrypt");
486 	if (err)
487 		goto err_unreg_kset;
488 
489 	err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
490 	if (err)
491 		goto err_deinit_pencrypt;
492 
493 	padata_start(pencrypt.pinst);
494 	padata_start(pdecrypt.pinst);
495 
496 	return crypto_register_template(&pcrypt_tmpl);
497 
498 err_deinit_pencrypt:
499 	pcrypt_fini_padata(&pencrypt);
500 err_unreg_kset:
501 	kset_unregister(pcrypt_kset);
502 err:
503 	return err;
504 }
505 
506 static void __exit pcrypt_exit(void)
507 {
508 	pcrypt_fini_padata(&pencrypt);
509 	pcrypt_fini_padata(&pdecrypt);
510 
511 	kset_unregister(pcrypt_kset);
512 	crypto_unregister_template(&pcrypt_tmpl);
513 }
514 
515 subsys_initcall(pcrypt_init);
516 module_exit(pcrypt_exit);
517 
518 MODULE_LICENSE("GPL");
519 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
520 MODULE_DESCRIPTION("Parallel crypto wrapper");
521 MODULE_ALIAS_CRYPTO("pcrypt");
522