crypto/pcrypt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * pcrypt - Parallel crypto wrapper.
   4  *
   5  * Copyright (C) 2009 secunet Security Networks AG
   6  * Copyright (C) 2009 Steffen Klassert <steffen.klassert@secunet.com>
   7  */
   8
   9 #include <crypto/algapi.h>
  10 #include <crypto/internal/aead.h>
  11 #include <linux/atomic.h>
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/notifier.h>
  17 #include <linux/kobject.h>
  18 #include <linux/cpu.h>
  19 #include <crypto/pcrypt.h>
  20
  21 struct padata_pcrypt {
  22         struct padata_instance *pinst;
  23         struct workqueue_struct *wq;
  24
  25         /*
  26          * Cpumask for callback CPUs. It should be
  27          * equal to serial cpumask of corresponding padata instance,
  28          * so it is updated when padata notifies us about serial
  29          * cpumask change.
  30          *
  31          * cb_cpumask is protected by RCU. This fact prevents us from
  32          * using cpumask_var_t directly because the actual type of
  33          * cpumsak_var_t depends on kernel configuration(particularly on
  34          * CONFIG_CPUMASK_OFFSTACK macro). Depending on the configuration
  35          * cpumask_var_t may be either a pointer to the struct cpumask
  36          * or a variable allocated on the stack. Thus we can not safely use
  37          * cpumask_var_t with RCU operations such as rcu_assign_pointer or
  38          * rcu_dereference. So cpumask_var_t is wrapped with struct
  39          * pcrypt_cpumask which makes possible to use it with RCU.
  40          */
  41         struct pcrypt_cpumask {
  42                 cpumask_var_t mask;
  43         } *cb_cpumask;
  44         struct notifier_block nblock;
  45 };
  46
  47 static struct padata_pcrypt pencrypt;
  48 static struct padata_pcrypt pdecrypt;
  49 static struct kset           *pcrypt_kset;
  50
  51 struct pcrypt_instance_ctx {
  52         struct crypto_aead_spawn spawn;
  53         atomic_t tfm_count;
  54 };
  55
  56 struct pcrypt_aead_ctx {
  57         struct crypto_aead *child;
  58         unsigned int cb_cpu;
  59 };
  60
  61 static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
  62                               struct padata_pcrypt *pcrypt)
  63 {
  64         unsigned int cpu_index, cpu, i;
  65         struct pcrypt_cpumask *cpumask;
  66
  67         cpu = *cb_cpu;
  68
  69         rcu_read_lock_bh();
  70         cpumask = rcu_dereference_bh(pcrypt->cb_cpumask);
  71         if (cpumask_test_cpu(cpu, cpumask->mask))
  72                         goto out;
  73
  74         if (!cpumask_weight(cpumask->mask))
  75                         goto out;
  76
  77         cpu_index = cpu % cpumask_weight(cpumask->mask);
  78
  79         cpu = cpumask_first(cpumask->mask);
  80         for (i = 0; i < cpu_index; i++)
  81                 cpu = cpumask_next(cpu, cpumask->mask);
  82
  83         *cb_cpu = cpu;
  84
  85 out:
  86         rcu_read_unlock_bh();
  87         return padata_do_parallel(pcrypt->pinst, padata, cpu);
  88 }
  89
  90 static int pcrypt_aead_setkey(struct crypto_aead *parent,
  91                               const u8 *key, unsigned int keylen)
  92 {
  93         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
  94
  95         return crypto_aead_setkey(ctx->child, key, keylen);
  96 }
  97
  98 static int pcrypt_aead_setauthsize(struct crypto_aead *parent,
  99                                    unsigned int authsize)
 100 {
 101         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
 102
 103         return crypto_aead_setauthsize(ctx->child, authsize);
 104 }
 105
 106 static void pcrypt_aead_serial(struct padata_priv *padata)
 107 {
 108         struct pcrypt_request *preq = pcrypt_padata_request(padata);
 109         struct aead_request *req = pcrypt_request_ctx(preq);
 110
 111         aead_request_complete(req->base.data, padata->info);
 112 }
 113
 114 static void pcrypt_aead_done(struct crypto_async_request *areq, int err)
 115 {
 116         struct aead_request *req = areq->data;
 117         struct pcrypt_request *preq = aead_request_ctx(req);
 118         struct padata_priv *padata = pcrypt_request_padata(preq);
 119
 120         padata->info = err;
 121         req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 122
 123         padata_do_serial(padata);
 124 }
 125
 126 static void pcrypt_aead_enc(struct padata_priv *padata)
 127 {
 128         struct pcrypt_request *preq = pcrypt_padata_request(padata);
 129         struct aead_request *req = pcrypt_request_ctx(preq);
 130
 131         padata->info = crypto_aead_encrypt(req);
 132
 133         if (padata->info == -EINPROGRESS)
 134                 return;
 135
 136         padata_do_serial(padata);
 137 }
 138
 139 static int pcrypt_aead_encrypt(struct aead_request *req)
 140 {
 141         int err;
 142         struct pcrypt_request *preq = aead_request_ctx(req);
 143         struct aead_request *creq = pcrypt_request_ctx(preq);
 144         struct padata_priv *padata = pcrypt_request_padata(preq);
 145         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 146         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
 147         u32 flags = aead_request_flags(req);
 148
 149         memset(padata, 0, sizeof(struct padata_priv));
 150
 151         padata->parallel = pcrypt_aead_enc;
 152         padata->serial = pcrypt_aead_serial;
 153
 154         aead_request_set_tfm(creq, ctx->child);
 155         aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 156                                   pcrypt_aead_done, req);
 157         aead_request_set_crypt(creq, req->src, req->dst,
 158                                req->cryptlen, req->iv);
 159         aead_request_set_ad(creq, req->assoclen);
 160
 161         err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
 162         if (!err)
 163                 return -EINPROGRESS;
 164
 165         return err;
 166 }
 167
 168 static void pcrypt_aead_dec(struct padata_priv *padata)
 169 {
 170         struct pcrypt_request *preq = pcrypt_padata_request(padata);
 171         struct aead_request *req = pcrypt_request_ctx(preq);
 172
 173         padata->info = crypto_aead_decrypt(req);
 174
 175         if (padata->info == -EINPROGRESS)
 176                 return;
 177
 178         padata_do_serial(padata);
 179 }
 180
 181 static int pcrypt_aead_decrypt(struct aead_request *req)
 182 {
 183         int err;
 184         struct pcrypt_request *preq = aead_request_ctx(req);
 185         struct aead_request *creq = pcrypt_request_ctx(preq);
 186         struct padata_priv *padata = pcrypt_request_padata(preq);
 187         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 188         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
 189         u32 flags = aead_request_flags(req);
 190
 191         memset(padata, 0, sizeof(struct padata_priv));
 192
 193         padata->parallel = pcrypt_aead_dec;
 194         padata->serial = pcrypt_aead_serial;
 195
 196         aead_request_set_tfm(creq, ctx->child);
 197         aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 198                                   pcrypt_aead_done, req);
 199         aead_request_set_crypt(creq, req->src, req->dst,
 200                                req->cryptlen, req->iv);
 201         aead_request_set_ad(creq, req->assoclen);
 202
 203         err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
 204         if (!err)
 205                 return -EINPROGRESS;
 206
 207         return err;
 208 }
 209
 210 static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
 211 {
 212         int cpu, cpu_index;
 213         struct aead_instance *inst = aead_alg_instance(tfm);
 214         struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
 215         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
 216         struct crypto_aead *cipher;
 217
 218         cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
 219                     cpumask_weight(cpu_online_mask);
 220
 221         ctx->cb_cpu = cpumask_first(cpu_online_mask);
 222         for (cpu = 0; cpu < cpu_index; cpu++)
 223                 ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
 224
 225         cipher = crypto_spawn_aead(&ictx->spawn);
 226
 227         if (IS_ERR(cipher))
 228                 return PTR_ERR(cipher);
 229
 230         ctx->child = cipher;
 231         crypto_aead_set_reqsize(tfm, sizeof(struct pcrypt_request) +
 232                                      sizeof(struct aead_request) +
 233                                      crypto_aead_reqsize(cipher));
 234
 235         return 0;
 236 }
 237
 238 static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm)
 239 {
 240         struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
 241
 242         crypto_free_aead(ctx->child);
 243 }
 244
 245 static void pcrypt_free(struct aead_instance *inst)
 246 {
 247         struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst);
 248
 249         crypto_drop_aead(&ctx->spawn);
 250         kfree(inst);
 251 }
 252
 253 static int pcrypt_init_instance(struct crypto_instance *inst,
 254                                 struct crypto_alg *alg)
 255 {
 256         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 257                      "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 258                 return -ENAMETOOLONG;
 259
 260         memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 261
 262         inst->alg.cra_priority = alg->cra_priority + 100;
 263         inst->alg.cra_blocksize = alg->cra_blocksize;
 264         inst->alg.cra_alignmask = alg->cra_alignmask;
 265
 266         return 0;
 267 }
 268
 269 static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
 270                               u32 type, u32 mask)
 271 {
 272         struct pcrypt_instance_ctx *ctx;
 273         struct crypto_attr_type *algt;
 274         struct aead_instance *inst;
 275         struct aead_alg *alg;
 276         const char *name;
 277         int err;
 278
 279         algt = crypto_get_attr_type(tb);
 280         if (IS_ERR(algt))
 281                 return PTR_ERR(algt);
 282
 283         name = crypto_attr_alg_name(tb[1]);
 284         if (IS_ERR(name))
 285                 return PTR_ERR(name);
 286
 287         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 288         if (!inst)
 289                 return -ENOMEM;
 290
 291         ctx = aead_instance_ctx(inst);
 292         crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
 293
 294         err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
 295         if (err)
 296                 goto out_free_inst;
 297
 298         alg = crypto_spawn_aead_alg(&ctx->spawn);
 299         err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
 300         if (err)
 301                 goto out_drop_aead;
 302
 303         inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC;
 304
 305         inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
 306         inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 307
 308         inst->alg.base.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
 309
 310         inst->alg.init = pcrypt_aead_init_tfm;
 311         inst->alg.exit = pcrypt_aead_exit_tfm;
 312
 313         inst->alg.setkey = pcrypt_aead_setkey;
 314         inst->alg.setauthsize = pcrypt_aead_setauthsize;
 315         inst->alg.encrypt = pcrypt_aead_encrypt;
 316         inst->alg.decrypt = pcrypt_aead_decrypt;
 317
 318         inst->free = pcrypt_free;
 319
 320         err = aead_register_instance(tmpl, inst);
 321         if (err)
 322                 goto out_drop_aead;
 323
 324 out:
 325         return err;
 326
 327 out_drop_aead:
 328         crypto_drop_aead(&ctx->spawn);
 329 out_free_inst:
 330         kfree(inst);
 331         goto out;
 332 }
 333
 334 static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb)
 335 {
 336         struct crypto_attr_type *algt;
 337
 338         algt = crypto_get_attr_type(tb);
 339         if (IS_ERR(algt))
 340                 return PTR_ERR(algt);
 341
 342         switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
 343         case CRYPTO_ALG_TYPE_AEAD:
 344                 return pcrypt_create_aead(tmpl, tb, algt->type, algt->mask);
 345         }
 346
 347         return -EINVAL;
 348 }
 349
 350 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
 351                                         unsigned long val, void *data)
 352 {
 353         struct padata_pcrypt *pcrypt;
 354         struct pcrypt_cpumask *new_mask, *old_mask;
 355         struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
 356
 357         if (!(val & PADATA_CPU_SERIAL))
 358                 return 0;
 359
 360         pcrypt = container_of(self, struct padata_pcrypt, nblock);
 361         new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
 362         if (!new_mask)
 363                 return -ENOMEM;
 364         if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
 365                 kfree(new_mask);
 366                 return -ENOMEM;
 367         }
 368
 369         old_mask = pcrypt->cb_cpumask;
 370
 371         cpumask_copy(new_mask->mask, cpumask->cbcpu);
 372         rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
 373         synchronize_rcu();
 374
 375         free_cpumask_var(old_mask->mask);
 376         kfree(old_mask);
 377         return 0;
 378 }
 379
 380 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
 381 {
 382         int ret;
 383
 384         pinst->kobj.kset = pcrypt_kset;
 385         ret = kobject_add(&pinst->kobj, NULL, "%s", name);
 386         if (!ret)
 387                 kobject_uevent(&pinst->kobj, KOBJ_ADD);
 388
 389         return ret;
 390 }
 391
 392 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
 393                               const char *name)
 394 {
 395         int ret = -ENOMEM;
 396         struct pcrypt_cpumask *mask;
 397
 398         get_online_cpus();
 399
 400         pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
 401                                      1, name);
 402         if (!pcrypt->wq)
 403                 goto err;
 404
 405         pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
 406         if (!pcrypt->pinst)
 407                 goto err_destroy_workqueue;
 408
 409         mask = kmalloc(sizeof(*mask), GFP_KERNEL);
 410         if (!mask)
 411                 goto err_free_padata;
 412         if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
 413                 kfree(mask);
 414                 goto err_free_padata;
 415         }
 416
 417         cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
 418         rcu_assign_pointer(pcrypt->cb_cpumask, mask);
 419
 420         pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
 421         ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 422         if (ret)
 423                 goto err_free_cpumask;
 424
 425         ret = pcrypt_sysfs_add(pcrypt->pinst, name);
 426         if (ret)
 427                 goto err_unregister_notifier;
 428
 429         put_online_cpus();
 430
 431         return ret;
 432
 433 err_unregister_notifier:
 434         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 435 err_free_cpumask:
 436         free_cpumask_var(mask->mask);
 437         kfree(mask);
 438 err_free_padata:
 439         padata_free(pcrypt->pinst);
 440 err_destroy_workqueue:
 441         destroy_workqueue(pcrypt->wq);
 442 err:
 443         put_online_cpus();
 444
 445         return ret;
 446 }
 447
 448 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
 449 {
 450         free_cpumask_var(pcrypt->cb_cpumask->mask);
 451         kfree(pcrypt->cb_cpumask);
 452
 453         padata_stop(pcrypt->pinst);
 454         padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
 455         destroy_workqueue(pcrypt->wq);
 456         padata_free(pcrypt->pinst);
 457 }
 458
 459 static struct crypto_template pcrypt_tmpl = {
 460         .name = "pcrypt",
 461         .create = pcrypt_create,
 462         .module = THIS_MODULE,
 463 };
 464
 465 static int __init pcrypt_init(void)
 466 {
 467         int err = -ENOMEM;
 468
 469         pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
 470         if (!pcrypt_kset)
 471                 goto err;
 472
 473         err = pcrypt_init_padata(&pencrypt, "pencrypt");
 474         if (err)
 475                 goto err_unreg_kset;
 476
 477         err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
 478         if (err)
 479                 goto err_deinit_pencrypt;
 480
 481         padata_start(pencrypt.pinst);
 482         padata_start(pdecrypt.pinst);
 483
 484         return crypto_register_template(&pcrypt_tmpl);
 485
 486 err_deinit_pencrypt:
 487         pcrypt_fini_padata(&pencrypt);
 488 err_unreg_kset:
 489         kset_unregister(pcrypt_kset);
 490 err:
 491         return err;
 492 }
 493
 494 static void __exit pcrypt_exit(void)
 495 {
 496         pcrypt_fini_padata(&pencrypt);
 497         pcrypt_fini_padata(&pdecrypt);
 498
 499         kset_unregister(pcrypt_kset);
 500         crypto_unregister_template(&pcrypt_tmpl);
 501 }
 502
 503 subsys_initcall(pcrypt_init);
 504 module_exit(pcrypt_exit);
 505
 506 MODULE_LICENSE("GPL");
 507 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
 508 MODULE_DESCRIPTION("Parallel crypto wrapper");
 509 MODULE_ALIAS_CRYPTO("pcrypt");