crypto/pcrypt.c

   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 int pcrypt_init_instance(struct crypto_instance *inst,
 258                                 struct crypto_alg *alg)
 259 {
 260         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 261                      "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 262                 return -ENAMETOOLONG;
 263
 264         memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 265
 266         inst->alg.cra_priority = alg->cra_priority + 100;
 267         inst->alg.cra_blocksize = alg->cra_blocksize;
 268         inst->alg.cra_alignmask = alg->cra_alignmask;
 269
 270         return 0;
 271 }
 272
 273 static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
 274                               u32 type, u32 mask)
 275 {
 276         struct pcrypt_instance_ctx *ctx;
 277         struct aead_instance *inst;
 278         struct aead_alg *alg;
 279         const char *name;
 280         int err;
 281
 282         name = crypto_attr_alg_name(tb[1]);
 283         if (IS_ERR(name))
 284                 return PTR_ERR(name);
 285
 286         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 287         if (!inst)
 288                 return -ENOMEM;
 289
 290         ctx = aead_instance_ctx(inst);
 291         crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
 292
 293         err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
 294         if (err)
 295                 goto out_free_inst;
 296
 297         alg = crypto_spawn_aead_alg(&ctx->spawn);
 298         err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
 299         if (err)
 300                 goto out_drop_aead;
 301
 302         inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
 303         inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 304
 305         inst->alg.base.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
 306
 307         inst->alg.init = pcrypt_aead_init_tfm;
 308         inst->alg.exit = pcrypt_aead_exit_tfm;
 309
 310         inst->alg.setkey = pcrypt_aead_setkey;
 311         inst->alg.setauthsize = pcrypt_aead_setauthsize;
 312         inst->alg.encrypt = pcrypt_aead_encrypt;
 313         inst->alg.decrypt = pcrypt_aead_decrypt;
 314
 315         err = aead_register_instance(tmpl, inst);
 316         if (err)
 317                 goto out_drop_aead;
 318
 319 out:
 320         return err;
 321
 322 out_drop_aead:
 323         crypto_drop_aead(&ctx->spawn);
 324 out_free_inst:
 325         kfree(inst);
 326         goto out;
 327 }
 328
 329 static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb)
 330 {
 331         struct crypto_attr_type *algt;
 332
 333         algt = crypto_get_attr_type(tb);
 334         if (IS_ERR(algt))
 335                 return PTR_ERR(algt);
 336
 337         switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
 338         case CRYPTO_ALG_TYPE_AEAD:
 339                 return pcrypt_create_aead(tmpl, tb, algt->type, algt->mask);
 340         }
 341
 342         return -EINVAL;
 343 }
 344
 345 static void pcrypt_free(struct crypto_instance *inst)
 346 {
 347         struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst);
 348
 349         crypto_drop_aead(&ctx->spawn);
 350         kfree(inst);
 351 }
 352
 353 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
 354                                         unsigned long val, void *data)
 355 {
 356         struct padata_pcrypt *pcrypt;
 357         struct pcrypt_cpumask *new_mask, *old_mask;
 358         struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
 359
 360         if (!(val & PADATA_CPU_SERIAL))
 361                 return 0;
 362
 363         pcrypt = container_of(self, struct padata_pcrypt, nblock);
 364         new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
 365         if (!new_mask)
 366                 return -ENOMEM;
 367         if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
 368                 kfree(new_mask);
 369                 return -ENOMEM;
 370         }
 371
 372         old_mask = pcrypt->cb_cpumask;
 373
 374         cpumask_copy(new_mask->mask, cpumask->cbcpu);
 375         rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
 376         synchronize_rcu_bh();
 377
 378         free_cpumask_var(old_mask->mask);
 379         kfree(old_mask);
 380         return 0;
 381 }
 382
 383 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
 384 {
 385         int ret;
 386
 387         pinst->kobj.kset = pcrypt_kset;
 388         ret = kobject_add(&pinst->kobj, NULL, name);
 389         if (!ret)
 390                 kobject_uevent(&pinst->kobj, KOBJ_ADD);
 391
 392         return ret;
 393 }
 394
 395 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
 396                               const char *name)
 397 {
 398         int ret = -ENOMEM;
 399         struct pcrypt_cpumask *mask;
 400
 401         get_online_cpus();
 402
 403         pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
 404                                      1, name);
 405         if (!pcrypt->wq)
 406                 goto err;
 407
 408         pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
 409         if (!pcrypt->pinst)
 410                 goto err_destroy_workqueue;
 411
 412         mask = kmalloc(sizeof(*mask), GFP_KERNEL);
 413         if (!mask)
 414                 goto err_free_padata;
 415         if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
 416                 kfree(mask);
 417                 goto err_free_padata;
 418         }
 419
 420         cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
 421         rcu_assign_pointer(pcrypt->cb_cpumask, mask);
 422
 423         pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
 424         ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 425         if (ret)
 426                 goto err_free_cpumask;
 427
 428         ret = pcrypt_sysfs_add(pcrypt->pinst, name);
 429         if (ret)
 430                 goto err_unregister_notifier;
 431
 432         put_online_cpus();
 433
 434         return ret;
 435
 436 err_unregister_notifier:
 437         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 438 err_free_cpumask:
 439         free_cpumask_var(mask->mask);
 440         kfree(mask);
 441 err_free_padata:
 442         padata_free(pcrypt->pinst);
 443 err_destroy_workqueue:
 444         destroy_workqueue(pcrypt->wq);
 445 err:
 446         put_online_cpus();
 447
 448         return ret;
 449 }
 450
 451 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
 452 {
 453         free_cpumask_var(pcrypt->cb_cpumask->mask);
 454         kfree(pcrypt->cb_cpumask);
 455
 456         padata_stop(pcrypt->pinst);
 457         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 458         destroy_workqueue(pcrypt->wq);
 459         padata_free(pcrypt->pinst);
 460 }
 461
 462 static struct crypto_template pcrypt_tmpl = {
 463         .name = "pcrypt",
 464         .create = pcrypt_create,
 465         .free = pcrypt_free,
 466         .module = THIS_MODULE,
 467 };
 468
 469 static int __init pcrypt_init(void)
 470 {
 471         int err = -ENOMEM;
 472
 473         pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
 474         if (!pcrypt_kset)
 475                 goto err;
 476
 477         err = pcrypt_init_padata(&pencrypt, "pencrypt");
 478         if (err)
 479                 goto err_unreg_kset;
 480
 481         err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
 482         if (err)
 483                 goto err_deinit_pencrypt;
 484
 485         padata_start(pencrypt.pinst);
 486         padata_start(pdecrypt.pinst);
 487
 488         return crypto_register_template(&pcrypt_tmpl);
 489
 490 err_deinit_pencrypt:
 491         pcrypt_fini_padata(&pencrypt);
 492 err_unreg_kset:
 493         kset_unregister(pcrypt_kset);
 494 err:
 495         return err;
 496 }
 497
 498 static void __exit pcrypt_exit(void)
 499 {
 500         pcrypt_fini_padata(&pencrypt);
 501         pcrypt_fini_padata(&pdecrypt);
 502
 503         kset_unregister(pcrypt_kset);
 504         crypto_unregister_template(&pcrypt_tmpl);
 505 }
 506
 507 module_init(pcrypt_init);
 508 module_exit(pcrypt_exit);
 509
 510 MODULE_LICENSE("GPL");
 511 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
 512 MODULE_DESCRIPTION("Parallel crypto wrapper");
 513 MODULE_ALIAS_CRYPTO("pcrypt");