xref: /openbmc/linux/crypto/pcrypt.c (revision 84764a41)
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/err.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/notifier.h>
28 #include <linux/kobject.h>
29 #include <linux/cpu.h>
30 #include <crypto/pcrypt.h>
31 
32 struct padata_pcrypt {
33 	struct padata_instance *pinst;
34 	struct workqueue_struct *wq;
35 
36 	/*
37 	 * Cpumask for callback CPUs. It should be
38 	 * equal to serial cpumask of corresponding padata instance,
39 	 * so it is updated when padata notifies us about serial
40 	 * cpumask change.
41 	 *
42 	 * cb_cpumask is protected by RCU. This fact prevents us from
43 	 * using cpumask_var_t directly because the actual type of
44 	 * cpumsak_var_t depends on kernel configuration(particularly on
45 	 * CONFIG_CPUMASK_OFFSTACK macro). Depending on the configuration
46 	 * cpumask_var_t may be either a pointer to the struct cpumask
47 	 * or a variable allocated on the stack. Thus we can not safely use
48 	 * cpumask_var_t with RCU operations such as rcu_assign_pointer or
49 	 * rcu_dereference. So cpumask_var_t is wrapped with struct
50 	 * pcrypt_cpumask which makes possible to use it with RCU.
51 	 */
52 	struct pcrypt_cpumask {
53 		cpumask_var_t mask;
54 	} *cb_cpumask;
55 	struct notifier_block nblock;
56 };
57 
58 static struct padata_pcrypt pencrypt;
59 static struct padata_pcrypt pdecrypt;
60 static struct kset           *pcrypt_kset;
61 
62 struct pcrypt_instance_ctx {
63 	struct crypto_spawn spawn;
64 	unsigned int tfm_count;
65 };
66 
67 struct pcrypt_aead_ctx {
68 	struct crypto_aead *child;
69 	unsigned int cb_cpu;
70 };
71 
72 static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
73 			      struct padata_pcrypt *pcrypt)
74 {
75 	unsigned int cpu_index, cpu, i;
76 	struct pcrypt_cpumask *cpumask;
77 
78 	cpu = *cb_cpu;
79 
80 	rcu_read_lock_bh();
81 	cpumask = rcu_dereference(pcrypt->cb_cpumask);
82 	if (cpumask_test_cpu(cpu, cpumask->mask))
83 			goto out;
84 
85 	if (!cpumask_weight(cpumask->mask))
86 			goto out;
87 
88 	cpu_index = cpu % cpumask_weight(cpumask->mask);
89 
90 	cpu = cpumask_first(cpumask->mask);
91 	for (i = 0; i < cpu_index; i++)
92 		cpu = cpumask_next(cpu, cpumask->mask);
93 
94 	*cb_cpu = cpu;
95 
96 out:
97 	rcu_read_unlock_bh();
98 	return padata_do_parallel(pcrypt->pinst, padata, cpu);
99 }
100 
101 static int pcrypt_aead_setkey(struct crypto_aead *parent,
102 			      const u8 *key, unsigned int keylen)
103 {
104 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
105 
106 	return crypto_aead_setkey(ctx->child, key, keylen);
107 }
108 
109 static int pcrypt_aead_setauthsize(struct crypto_aead *parent,
110 				   unsigned int authsize)
111 {
112 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
113 
114 	return crypto_aead_setauthsize(ctx->child, authsize);
115 }
116 
117 static void pcrypt_aead_serial(struct padata_priv *padata)
118 {
119 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
120 	struct aead_request *req = pcrypt_request_ctx(preq);
121 
122 	aead_request_complete(req->base.data, padata->info);
123 }
124 
125 static void pcrypt_aead_giv_serial(struct padata_priv *padata)
126 {
127 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
128 	struct aead_givcrypt_request *req = pcrypt_request_ctx(preq);
129 
130 	aead_request_complete(req->areq.base.data, padata->info);
131 }
132 
133 static void pcrypt_aead_done(struct crypto_async_request *areq, int err)
134 {
135 	struct aead_request *req = areq->data;
136 	struct pcrypt_request *preq = aead_request_ctx(req);
137 	struct padata_priv *padata = pcrypt_request_padata(preq);
138 
139 	padata->info = err;
140 	req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
141 
142 	padata_do_serial(padata);
143 }
144 
145 static void pcrypt_aead_enc(struct padata_priv *padata)
146 {
147 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
148 	struct aead_request *req = pcrypt_request_ctx(preq);
149 
150 	padata->info = crypto_aead_encrypt(req);
151 
152 	if (padata->info == -EINPROGRESS)
153 		return;
154 
155 	padata_do_serial(padata);
156 }
157 
158 static int pcrypt_aead_encrypt(struct aead_request *req)
159 {
160 	int err;
161 	struct pcrypt_request *preq = aead_request_ctx(req);
162 	struct aead_request *creq = pcrypt_request_ctx(preq);
163 	struct padata_priv *padata = pcrypt_request_padata(preq);
164 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
165 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
166 	u32 flags = aead_request_flags(req);
167 
168 	memset(padata, 0, sizeof(struct padata_priv));
169 
170 	padata->parallel = pcrypt_aead_enc;
171 	padata->serial = pcrypt_aead_serial;
172 
173 	aead_request_set_tfm(creq, ctx->child);
174 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
175 				  pcrypt_aead_done, req);
176 	aead_request_set_crypt(creq, req->src, req->dst,
177 			       req->cryptlen, req->iv);
178 	aead_request_set_assoc(creq, req->assoc, req->assoclen);
179 
180 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
181 	if (!err)
182 		return -EINPROGRESS;
183 
184 	return err;
185 }
186 
187 static void pcrypt_aead_dec(struct padata_priv *padata)
188 {
189 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
190 	struct aead_request *req = pcrypt_request_ctx(preq);
191 
192 	padata->info = crypto_aead_decrypt(req);
193 
194 	if (padata->info == -EINPROGRESS)
195 		return;
196 
197 	padata_do_serial(padata);
198 }
199 
200 static int pcrypt_aead_decrypt(struct aead_request *req)
201 {
202 	int err;
203 	struct pcrypt_request *preq = aead_request_ctx(req);
204 	struct aead_request *creq = pcrypt_request_ctx(preq);
205 	struct padata_priv *padata = pcrypt_request_padata(preq);
206 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
207 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
208 	u32 flags = aead_request_flags(req);
209 
210 	memset(padata, 0, sizeof(struct padata_priv));
211 
212 	padata->parallel = pcrypt_aead_dec;
213 	padata->serial = pcrypt_aead_serial;
214 
215 	aead_request_set_tfm(creq, ctx->child);
216 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
217 				  pcrypt_aead_done, req);
218 	aead_request_set_crypt(creq, req->src, req->dst,
219 			       req->cryptlen, req->iv);
220 	aead_request_set_assoc(creq, req->assoc, req->assoclen);
221 
222 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
223 	if (!err)
224 		return -EINPROGRESS;
225 
226 	return err;
227 }
228 
229 static void pcrypt_aead_givenc(struct padata_priv *padata)
230 {
231 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
232 	struct aead_givcrypt_request *req = pcrypt_request_ctx(preq);
233 
234 	padata->info = crypto_aead_givencrypt(req);
235 
236 	if (padata->info == -EINPROGRESS)
237 		return;
238 
239 	padata_do_serial(padata);
240 }
241 
242 static int pcrypt_aead_givencrypt(struct aead_givcrypt_request *req)
243 {
244 	int err;
245 	struct aead_request *areq = &req->areq;
246 	struct pcrypt_request *preq = aead_request_ctx(areq);
247 	struct aead_givcrypt_request *creq = pcrypt_request_ctx(preq);
248 	struct padata_priv *padata = pcrypt_request_padata(preq);
249 	struct crypto_aead *aead = aead_givcrypt_reqtfm(req);
250 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
251 	u32 flags = aead_request_flags(areq);
252 
253 	memset(padata, 0, sizeof(struct padata_priv));
254 
255 	padata->parallel = pcrypt_aead_givenc;
256 	padata->serial = pcrypt_aead_giv_serial;
257 
258 	aead_givcrypt_set_tfm(creq, ctx->child);
259 	aead_givcrypt_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
260 				   pcrypt_aead_done, areq);
261 	aead_givcrypt_set_crypt(creq, areq->src, areq->dst,
262 				areq->cryptlen, areq->iv);
263 	aead_givcrypt_set_assoc(creq, areq->assoc, areq->assoclen);
264 	aead_givcrypt_set_giv(creq, req->giv, req->seq);
265 
266 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
267 	if (!err)
268 		return -EINPROGRESS;
269 
270 	return err;
271 }
272 
273 static int pcrypt_aead_init_tfm(struct crypto_tfm *tfm)
274 {
275 	int cpu, cpu_index;
276 	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
277 	struct pcrypt_instance_ctx *ictx = crypto_instance_ctx(inst);
278 	struct pcrypt_aead_ctx *ctx = crypto_tfm_ctx(tfm);
279 	struct crypto_aead *cipher;
280 
281 	ictx->tfm_count++;
282 
283 	cpu_index = ictx->tfm_count % cpumask_weight(cpu_online_mask);
284 
285 	ctx->cb_cpu = cpumask_first(cpu_online_mask);
286 	for (cpu = 0; cpu < cpu_index; cpu++)
287 		ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
288 
289 	cipher = crypto_spawn_aead(crypto_instance_ctx(inst));
290 
291 	if (IS_ERR(cipher))
292 		return PTR_ERR(cipher);
293 
294 	ctx->child = cipher;
295 	tfm->crt_aead.reqsize = sizeof(struct pcrypt_request)
296 		+ sizeof(struct aead_givcrypt_request)
297 		+ crypto_aead_reqsize(cipher);
298 
299 	return 0;
300 }
301 
302 static void pcrypt_aead_exit_tfm(struct crypto_tfm *tfm)
303 {
304 	struct pcrypt_aead_ctx *ctx = crypto_tfm_ctx(tfm);
305 
306 	crypto_free_aead(ctx->child);
307 }
308 
309 static struct crypto_instance *pcrypt_alloc_instance(struct crypto_alg *alg)
310 {
311 	struct crypto_instance *inst;
312 	struct pcrypt_instance_ctx *ctx;
313 	int err;
314 
315 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
316 	if (!inst) {
317 		inst = ERR_PTR(-ENOMEM);
318 		goto out;
319 	}
320 
321 	err = -ENAMETOOLONG;
322 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
323 		     "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
324 		goto out_free_inst;
325 
326 	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
327 
328 	ctx = crypto_instance_ctx(inst);
329 	err = crypto_init_spawn(&ctx->spawn, alg, inst,
330 				CRYPTO_ALG_TYPE_MASK);
331 	if (err)
332 		goto out_free_inst;
333 
334 	inst->alg.cra_priority = alg->cra_priority + 100;
335 	inst->alg.cra_blocksize = alg->cra_blocksize;
336 	inst->alg.cra_alignmask = alg->cra_alignmask;
337 
338 out:
339 	return inst;
340 
341 out_free_inst:
342 	kfree(inst);
343 	inst = ERR_PTR(err);
344 	goto out;
345 }
346 
347 static struct crypto_instance *pcrypt_alloc_aead(struct rtattr **tb,
348 						 u32 type, u32 mask)
349 {
350 	struct crypto_instance *inst;
351 	struct crypto_alg *alg;
352 
353 	alg = crypto_get_attr_alg(tb, type, (mask & CRYPTO_ALG_TYPE_MASK));
354 	if (IS_ERR(alg))
355 		return ERR_CAST(alg);
356 
357 	inst = pcrypt_alloc_instance(alg);
358 	if (IS_ERR(inst))
359 		goto out_put_alg;
360 
361 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
362 	inst->alg.cra_type = &crypto_aead_type;
363 
364 	inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
365 	inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
366 	inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
367 
368 	inst->alg.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
369 
370 	inst->alg.cra_init = pcrypt_aead_init_tfm;
371 	inst->alg.cra_exit = pcrypt_aead_exit_tfm;
372 
373 	inst->alg.cra_aead.setkey = pcrypt_aead_setkey;
374 	inst->alg.cra_aead.setauthsize = pcrypt_aead_setauthsize;
375 	inst->alg.cra_aead.encrypt = pcrypt_aead_encrypt;
376 	inst->alg.cra_aead.decrypt = pcrypt_aead_decrypt;
377 	inst->alg.cra_aead.givencrypt = pcrypt_aead_givencrypt;
378 
379 out_put_alg:
380 	crypto_mod_put(alg);
381 	return inst;
382 }
383 
384 static struct crypto_instance *pcrypt_alloc(struct rtattr **tb)
385 {
386 	struct crypto_attr_type *algt;
387 
388 	algt = crypto_get_attr_type(tb);
389 	if (IS_ERR(algt))
390 		return ERR_CAST(algt);
391 
392 	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
393 	case CRYPTO_ALG_TYPE_AEAD:
394 		return pcrypt_alloc_aead(tb, algt->type, algt->mask);
395 	}
396 
397 	return ERR_PTR(-EINVAL);
398 }
399 
400 static void pcrypt_free(struct crypto_instance *inst)
401 {
402 	struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst);
403 
404 	crypto_drop_spawn(&ctx->spawn);
405 	kfree(inst);
406 }
407 
408 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
409 					unsigned long val, void *data)
410 {
411 	struct padata_pcrypt *pcrypt;
412 	struct pcrypt_cpumask *new_mask, *old_mask;
413 	struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
414 
415 	if (!(val & PADATA_CPU_SERIAL))
416 		return 0;
417 
418 	pcrypt = container_of(self, struct padata_pcrypt, nblock);
419 	new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
420 	if (!new_mask)
421 		return -ENOMEM;
422 	if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
423 		kfree(new_mask);
424 		return -ENOMEM;
425 	}
426 
427 	old_mask = pcrypt->cb_cpumask;
428 
429 	cpumask_copy(new_mask->mask, cpumask->cbcpu);
430 	rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
431 	synchronize_rcu_bh();
432 
433 	free_cpumask_var(old_mask->mask);
434 	kfree(old_mask);
435 	return 0;
436 }
437 
438 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
439 {
440 	int ret;
441 
442 	pinst->kobj.kset = pcrypt_kset;
443 	ret = kobject_add(&pinst->kobj, NULL, name);
444 	if (!ret)
445 		kobject_uevent(&pinst->kobj, KOBJ_ADD);
446 
447 	return ret;
448 }
449 
450 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
451 			      const char *name)
452 {
453 	int ret = -ENOMEM;
454 	struct pcrypt_cpumask *mask;
455 
456 	get_online_cpus();
457 
458 	pcrypt->wq = alloc_workqueue(name,
459 				     WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, 1);
460 	if (!pcrypt->wq)
461 		goto err;
462 
463 	pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
464 	if (!pcrypt->pinst)
465 		goto err_destroy_workqueue;
466 
467 	mask = kmalloc(sizeof(*mask), GFP_KERNEL);
468 	if (!mask)
469 		goto err_free_padata;
470 	if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
471 		kfree(mask);
472 		goto err_free_padata;
473 	}
474 
475 	cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
476 	rcu_assign_pointer(pcrypt->cb_cpumask, mask);
477 
478 	pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
479 	ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
480 	if (ret)
481 		goto err_free_cpumask;
482 
483 	ret = pcrypt_sysfs_add(pcrypt->pinst, name);
484 	if (ret)
485 		goto err_unregister_notifier;
486 
487 	put_online_cpus();
488 
489 	return ret;
490 
491 err_unregister_notifier:
492 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
493 err_free_cpumask:
494 	free_cpumask_var(mask->mask);
495 	kfree(mask);
496 err_free_padata:
497 	padata_free(pcrypt->pinst);
498 err_destroy_workqueue:
499 	destroy_workqueue(pcrypt->wq);
500 err:
501 	put_online_cpus();
502 
503 	return ret;
504 }
505 
506 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
507 {
508 	free_cpumask_var(pcrypt->cb_cpumask->mask);
509 	kfree(pcrypt->cb_cpumask);
510 
511 	padata_stop(pcrypt->pinst);
512 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
513 	destroy_workqueue(pcrypt->wq);
514 	padata_free(pcrypt->pinst);
515 }
516 
517 static struct crypto_template pcrypt_tmpl = {
518 	.name = "pcrypt",
519 	.alloc = pcrypt_alloc,
520 	.free = pcrypt_free,
521 	.module = THIS_MODULE,
522 };
523 
524 static int __init pcrypt_init(void)
525 {
526 	int err = -ENOMEM;
527 
528 	pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
529 	if (!pcrypt_kset)
530 		goto err;
531 
532 	err = pcrypt_init_padata(&pencrypt, "pencrypt");
533 	if (err)
534 		goto err_unreg_kset;
535 
536 	err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
537 	if (err)
538 		goto err_deinit_pencrypt;
539 
540 	padata_start(pencrypt.pinst);
541 	padata_start(pdecrypt.pinst);
542 
543 	return crypto_register_template(&pcrypt_tmpl);
544 
545 err_deinit_pencrypt:
546 	pcrypt_fini_padata(&pencrypt);
547 err_unreg_kset:
548 	kset_unregister(pcrypt_kset);
549 err:
550 	return err;
551 }
552 
553 static void __exit pcrypt_exit(void)
554 {
555 	pcrypt_fini_padata(&pencrypt);
556 	pcrypt_fini_padata(&pdecrypt);
557 
558 	kset_unregister(pcrypt_kset);
559 	crypto_unregister_template(&pcrypt_tmpl);
560 }
561 
562 module_init(pcrypt_init);
563 module_exit(pcrypt_exit);
564 
565 MODULE_LICENSE("GPL");
566 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
567 MODULE_DESCRIPTION("Parallel crypto wrapper");
568