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