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
 134         padata_do_serial(padata);
 135 }
 136
 137 static void pcrypt_aead_enc(struct padata_priv *padata)
 138 {
 139         struct pcrypt_request *preq = pcrypt_padata_request(padata);
 140         struct aead_request *req = pcrypt_request_ctx(preq);
 141
 142         padata->info = crypto_aead_encrypt(req);
 143
 144         if (padata->info == -EINPROGRESS)
 145                 return;
 146
 147         padata_do_serial(padata);
 148 }
 149
 150 static int pcrypt_aead_encrypt(struct aead_request *req)
 151 {
 152         int err;
 153         struct pcrypt_request *preq = aead_request_ctx(req);
 154         struct aead_request *creq = pcrypt_request_ctx(preq);
 155         struct padata_priv *padata = pcrypt_request_padata(preq);
 156         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 157         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
 158         u32 flags = aead_request_flags(req);
 159
 160         memset(padata, 0, sizeof(struct padata_priv));
 161
 162         padata->parallel = pcrypt_aead_enc;
 163         padata->serial = pcrypt_aead_serial;
 164
 165         aead_request_set_tfm(creq, ctx->child);
 166         aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 167                                   pcrypt_aead_done, req);
 168         aead_request_set_crypt(creq, req->src, req->dst,
 169                                req->cryptlen, req->iv);
 170         aead_request_set_ad(creq, req->assoclen);
 171
 172         err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
 173         if (!err)
 174                 return -EINPROGRESS;
 175
 176         return err;
 177 }
 178
 179 static void pcrypt_aead_dec(struct padata_priv *padata)
 180 {
 181         struct pcrypt_request *preq = pcrypt_padata_request(padata);
 182         struct aead_request *req = pcrypt_request_ctx(preq);
 183
 184         padata->info = crypto_aead_decrypt(req);
 185
 186         if (padata->info == -EINPROGRESS)
 187                 return;
 188
 189         padata_do_serial(padata);
 190 }
 191
 192 static int pcrypt_aead_decrypt(struct aead_request *req)
 193 {
 194         int err;
 195         struct pcrypt_request *preq = aead_request_ctx(req);
 196         struct aead_request *creq = pcrypt_request_ctx(preq);
 197         struct padata_priv *padata = pcrypt_request_padata(preq);
 198         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 199         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
 200         u32 flags = aead_request_flags(req);
 201
 202         memset(padata, 0, sizeof(struct padata_priv));
 203
 204         padata->parallel = pcrypt_aead_dec;
 205         padata->serial = pcrypt_aead_serial;
 206
 207         aead_request_set_tfm(creq, ctx->child);
 208         aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 209                                   pcrypt_aead_done, req);
 210         aead_request_set_crypt(creq, req->src, req->dst,
 211                                req->cryptlen, req->iv);
 212         aead_request_set_ad(creq, req->assoclen);
 213
 214         err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
 215         if (!err)
 216                 return -EINPROGRESS;
 217
 218         return err;
 219 }
 220
 221 static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
 222 {
 223         int cpu, cpu_index;
 224         struct aead_instance *inst = aead_alg_instance(tfm);
 225         struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
 226         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
 227         struct crypto_aead *cipher;
 228
 229         cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
 230                     cpumask_weight(cpu_online_mask);
 231
 232         ctx->cb_cpu = cpumask_first(cpu_online_mask);
 233         for (cpu = 0; cpu < cpu_index; cpu++)
 234                 ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
 235
 236         cipher = crypto_spawn_aead(&ictx->spawn);
 237
 238         if (IS_ERR(cipher))
 239                 return PTR_ERR(cipher);
 240
 241         ctx->child = cipher;
 242         crypto_aead_set_reqsize(tfm, sizeof(struct pcrypt_request) +
 243                                      sizeof(struct aead_request) +
 244                                      crypto_aead_reqsize(cipher));
 245
 246         return 0;
 247 }
 248
 249 static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm)
 250 {
 251         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
 252
 253         crypto_free_aead(ctx->child);
 254 }
 255
 256 static void pcrypt_free(struct aead_instance *inst)
 257 {
 258         struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst);
 259
 260         crypto_drop_aead(&ctx->spawn);
 261         kfree(inst);
 262 }
 263
 264 static int pcrypt_init_instance(struct crypto_instance *inst,
 265                                 struct crypto_alg *alg)
 266 {
 267         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 268                      "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 269                 return -ENAMETOOLONG;
 270
 271         memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 272
 273         inst->alg.cra_priority = alg->cra_priority + 100;
 274         inst->alg.cra_blocksize = alg->cra_blocksize;
 275         inst->alg.cra_alignmask = alg->cra_alignmask;
 276
 277         return 0;
 278 }
 279
 280 static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
 281                               u32 type, u32 mask)
 282 {
 283         struct pcrypt_instance_ctx *ctx;
 284         struct crypto_attr_type *algt;
 285         struct aead_instance *inst;
 286         struct aead_alg *alg;
 287         const char *name;
 288         int err;
 289
 290         algt = crypto_get_attr_type(tb);
 291         if (IS_ERR(algt))
 292                 return PTR_ERR(algt);
 293
 294         name = crypto_attr_alg_name(tb[1]);
 295         if (IS_ERR(name))
 296                 return PTR_ERR(name);
 297
 298         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 299         if (!inst)
 300                 return -ENOMEM;
 301
 302         ctx = aead_instance_ctx(inst);
 303         crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
 304
 305         err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
 306         if (err)
 307                 goto out_free_inst;
 308
 309         alg = crypto_spawn_aead_alg(&ctx->spawn);
 310         err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
 311         if (err)
 312                 goto out_drop_aead;
 313
 314         inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC;
 315
 316         inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
 317         inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 318
 319         inst->alg.base.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
 320
 321         inst->alg.init = pcrypt_aead_init_tfm;
 322         inst->alg.exit = pcrypt_aead_exit_tfm;
 323
 324         inst->alg.setkey = pcrypt_aead_setkey;
 325         inst->alg.setauthsize = pcrypt_aead_setauthsize;
 326         inst->alg.encrypt = pcrypt_aead_encrypt;
 327         inst->alg.decrypt = pcrypt_aead_decrypt;
 328
 329         inst->free = pcrypt_free;
 330
 331         err = aead_register_instance(tmpl, inst);
 332         if (err)
 333                 goto out_drop_aead;
 334
 335 out:
 336         return err;
 337
 338 out_drop_aead:
 339         crypto_drop_aead(&ctx->spawn);
 340 out_free_inst:
 341         kfree(inst);
 342         goto out;
 343 }
 344
 345 static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb)
 346 {
 347         struct crypto_attr_type *algt;
 348
 349         algt = crypto_get_attr_type(tb);
 350         if (IS_ERR(algt))
 351                 return PTR_ERR(algt);
 352
 353         switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
 354         case CRYPTO_ALG_TYPE_AEAD:
 355                 return pcrypt_create_aead(tmpl, tb, algt->type, algt->mask);
 356         }
 357
 358         return -EINVAL;
 359 }
 360
 361 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
 362                                         unsigned long val, void *data)
 363 {
 364         struct padata_pcrypt *pcrypt;
 365         struct pcrypt_cpumask *new_mask, *old_mask;
 366         struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
 367
 368         if (!(val & PADATA_CPU_SERIAL))
 369                 return 0;
 370
 371         pcrypt = container_of(self, struct padata_pcrypt, nblock);
 372         new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
 373         if (!new_mask)
 374                 return -ENOMEM;
 375         if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
 376                 kfree(new_mask);
 377                 return -ENOMEM;
 378         }
 379
 380         old_mask = pcrypt->cb_cpumask;
 381
 382         cpumask_copy(new_mask->mask, cpumask->cbcpu);
 383         rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
 384         synchronize_rcu_bh();
 385
 386         free_cpumask_var(old_mask->mask);
 387         kfree(old_mask);
 388         return 0;
 389 }
 390
 391 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
 392 {
 393         int ret;
 394
 395         pinst->kobj.kset = pcrypt_kset;
 396         ret = kobject_add(&pinst->kobj, NULL, "%s", name);
 397         if (!ret)
 398                 kobject_uevent(&pinst->kobj, KOBJ_ADD);
 399
 400         return ret;
 401 }
 402
 403 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
 404                               const char *name)
 405 {
 406         int ret = -ENOMEM;
 407         struct pcrypt_cpumask *mask;
 408
 409         get_online_cpus();
 410
 411         pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
 412                                      1, name);
 413         if (!pcrypt->wq)
 414                 goto err;
 415
 416         pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
 417         if (!pcrypt->pinst)
 418                 goto err_destroy_workqueue;
 419
 420         mask = kmalloc(sizeof(*mask), GFP_KERNEL);
 421         if (!mask)
 422                 goto err_free_padata;
 423         if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
 424                 kfree(mask);
 425                 goto err_free_padata;
 426         }
 427
 428         cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
 429         rcu_assign_pointer(pcrypt->cb_cpumask, mask);
 430
 431         pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
 432         ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 433         if (ret)
 434                 goto err_free_cpumask;
 435
 436         ret = pcrypt_sysfs_add(pcrypt->pinst, name);
 437         if (ret)
 438                 goto err_unregister_notifier;
 439
 440         put_online_cpus();
 441
 442         return ret;
 443
 444 err_unregister_notifier:
 445         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 446 err_free_cpumask:
 447         free_cpumask_var(mask->mask);
 448         kfree(mask);
 449 err_free_padata:
 450         padata_free(pcrypt->pinst);
 451 err_destroy_workqueue:
 452         destroy_workqueue(pcrypt->wq);
 453 err:
 454         put_online_cpus();
 455
 456         return ret;
 457 }
 458
 459 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
 460 {
 461         free_cpumask_var(pcrypt->cb_cpumask->mask);
 462         kfree(pcrypt->cb_cpumask);
 463
 464         padata_stop(pcrypt->pinst);
 465         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 466         destroy_workqueue(pcrypt->wq);
 467         padata_free(pcrypt->pinst);
 468 }
 469
 470 static struct crypto_template pcrypt_tmpl = {
 471         .name = "pcrypt",
 472         .create = pcrypt_create,
 473         .module = THIS_MODULE,
 474 };
 475
 476 static int __init pcrypt_init(void)
 477 {
 478         int err = -ENOMEM;
 479
 480         pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
 481         if (!pcrypt_kset)
 482                 goto err;
 483
 484         err = pcrypt_init_padata(&pencrypt, "pencrypt");
 485         if (err)
 486                 goto err_unreg_kset;
 487
 488         err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
 489         if (err)
 490                 goto err_deinit_pencrypt;
 491
 492         padata_start(pencrypt.pinst);
 493         padata_start(pdecrypt.pinst);
 494
 495         return crypto_register_template(&pcrypt_tmpl);
 496
 497 err_deinit_pencrypt:
 498         pcrypt_fini_padata(&pencrypt);
 499 err_unreg_kset:
 500         kset_unregister(pcrypt_kset);
 501 err:
 502         return err;
 503 }
 504
 505 static void __exit pcrypt_exit(void)
 506 {
 507         crypto_unregister_template(&pcrypt_tmpl);
 508
 509         pcrypt_fini_padata(&pencrypt);
 510         pcrypt_fini_padata(&pdecrypt);
 511
 512         kset_unregister(pcrypt_kset);
 513 }
 514
 515 module_init(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");