drivers/staging/lustre/lnet/libcfs/linux/linux-crypto.c

   1 /* GPL HEADER START
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License version 2 for more details (a copy is included
  13  * in the LICENSE file that accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * version 2 along with this program; If not, see http://www.gnu.org/licenses
  17  *
  18  * Please  visit http://www.xyratex.com/contact if you need additional
  19  * information or have any questions.
  20  *
  21  * GPL HEADER END
  22  */
  23
  24 /*
  25  * Copyright 2012 Xyratex Technology Limited
  26  *
  27  * Copyright (c) 2012, Intel Corporation.
  28  */
  29
  30 #include <crypto/hash.h>
  31 #include <linux/scatterlist.h>
  32 #include "../../../include/linux/libcfs/libcfs.h"
  33 #include "../../../include/linux/libcfs/libcfs_crypto.h"
  34 #include "linux-crypto.h"
  35
  36 /**
  37  *  Array of hash algorithm speed in MByte per second
  38  */
  39 static int cfs_crypto_hash_speeds[CFS_HASH_ALG_MAX];
  40
  41 /**
  42  * Initialize the state descriptor for the specified hash algorithm.
  43  *
  44  * An internal routine to allocate the hash-specific state in \a hdesc for
  45  * use with cfs_crypto_hash_digest() to compute the hash of a single message,
  46  * though possibly in multiple chunks.  The descriptor internal state should
  47  * be freed with cfs_crypto_hash_final().
  48  *
  49  * \param[in]     hash_alg      hash algorithm id (CFS_HASH_ALG_*)
  50  * \param[out]    type          pointer to the hash description in hash_types[]
  51  *                              array
  52  * \param[in,out] hdesc         hash state descriptor to be initialized
  53  * \param[in]     key           initial hash value/state, NULL to use default
  54  *                              value
  55  * \param[in]     key_len       length of \a key
  56  *
  57  * \retval                      0 on success
  58  * \retval                      negative errno on failure
  59  */
  60 static int cfs_crypto_hash_alloc(enum cfs_crypto_hash_alg hash_alg,
  61                                  const struct cfs_crypto_hash_type **type,
  62                                  struct ahash_request **req,
  63                                  unsigned char *key,
  64                                  unsigned int key_len)
  65 {
  66         struct crypto_ahash *tfm;
  67         int     err = 0;
  68
  69         *type = cfs_crypto_hash_type(hash_alg);
  70
  71         if (!*type) {
  72                 CWARN("Unsupported hash algorithm id = %d, max id is %d\n",
  73                       hash_alg, CFS_HASH_ALG_MAX);
  74                 return -EINVAL;
  75         }
  76         tfm = crypto_alloc_ahash((*type)->cht_name, 0, CRYPTO_ALG_ASYNC);
  77
  78         if (IS_ERR(tfm)) {
  79                 CDEBUG(D_INFO, "Failed to alloc crypto hash %s\n",
  80                        (*type)->cht_name);
  81                 return PTR_ERR(tfm);
  82         }
  83
  84         *req = ahash_request_alloc(tfm, GFP_KERNEL);
  85         if (!*req) {
  86                 CDEBUG(D_INFO, "Failed to alloc ahash_request for %s\n",
  87                        (*type)->cht_name);
  88                 crypto_free_ahash(tfm);
  89                 return -ENOMEM;
  90         }
  91
  92         ahash_request_set_callback(*req, 0, NULL, NULL);
  93
  94         if (key)
  95                 err = crypto_ahash_setkey(tfm, key, key_len);
  96         else if ((*type)->cht_key != 0)
  97                 err = crypto_ahash_setkey(tfm,
  98                                          (unsigned char *)&((*type)->cht_key),
  99                                          (*type)->cht_size);
 100
 101         if (err != 0) {
 102                 ahash_request_free(*req);
 103                 crypto_free_ahash(tfm);
 104                 return err;
 105         }
 106
 107         CDEBUG(D_INFO, "Using crypto hash: %s (%s) speed %d MB/s\n",
 108                crypto_ahash_alg_name(tfm), crypto_ahash_driver_name(tfm),
 109                cfs_crypto_hash_speeds[hash_alg]);
 110
 111         err = crypto_ahash_init(*req);
 112         if (err) {
 113                 ahash_request_free(*req);
 114                 crypto_free_ahash(tfm);
 115         }
 116         return err;
 117 }
 118
 119 /**
 120  * Calculate hash digest for the passed buffer.
 121  *
 122  * This should be used when computing the hash on a single contiguous buffer.
 123  * It combines the hash initialization, computation, and cleanup.
 124  *
 125  * \param[in]     hash_alg      id of hash algorithm (CFS_HASH_ALG_*)
 126  * \param[in]     buf           data buffer on which to compute hash
 127  * \param[in]     buf_len       length of \a buf in bytes
 128  * \param[in]     key           initial value/state for algorithm,
 129  *                              if \a key = NULL use default initial value
 130  * \param[in]     key_len       length of \a key in bytes
 131  * \param[out]    hash          pointer to computed hash value,
 132  *                              if \a hash = NULL then \a hash_len is to digest
 133  *                              size in bytes, retval -ENOSPC
 134  * \param[in,out] hash_len      size of \a hash buffer
 135  *
 136  * \retval -EINVAL              \a buf, \a buf_len, \a hash_len,
 137  *                              \a hash_alg invalid
 138  * \retval -ENOENT              \a hash_alg is unsupported
 139  * \retval -ENOSPC              \a hash is NULL, or \a hash_len less than
 140  *                              digest size
 141  * \retval                      0 for success
 142  * \retval                      negative errno for other errors from lower
 143  *                              layers.
 144  */
 145 int cfs_crypto_hash_digest(enum cfs_crypto_hash_alg hash_alg,
 146                            const void *buf, unsigned int buf_len,
 147                            unsigned char *key, unsigned int key_len,
 148                            unsigned char *hash, unsigned int *hash_len)
 149 {
 150         struct scatterlist      sl;
 151         struct ahash_request *req;
 152         int                     err;
 153         const struct cfs_crypto_hash_type       *type;
 154
 155         if (!buf || buf_len == 0 || !hash_len)
 156                 return -EINVAL;
 157
 158         err = cfs_crypto_hash_alloc(hash_alg, &type, &req, key, key_len);
 159         if (err != 0)
 160                 return err;
 161
 162         if (!hash || *hash_len < type->cht_size) {
 163                 *hash_len = type->cht_size;
 164                 crypto_free_ahash(crypto_ahash_reqtfm(req));
 165                 ahash_request_free(req);
 166                 return -ENOSPC;
 167         }
 168         sg_init_one(&sl, buf, buf_len);
 169
 170         ahash_request_set_crypt(req, &sl, hash, sl.length);
 171         err = crypto_ahash_digest(req);
 172         crypto_free_ahash(crypto_ahash_reqtfm(req));
 173         ahash_request_free(req);
 174
 175         return err;
 176 }
 177 EXPORT_SYMBOL(cfs_crypto_hash_digest);
 178
 179 /**
 180  * Allocate and initialize desriptor for hash algorithm.
 181  *
 182  * This should be used to initialize a hash descriptor for multiple calls
 183  * to a single hash function when computing the hash across multiple
 184  * separate buffers or pages using cfs_crypto_hash_update{,_page}().
 185  *
 186  * The hash descriptor should be freed with cfs_crypto_hash_final().
 187  *
 188  * \param[in] hash_alg  algorithm id (CFS_HASH_ALG_*)
 189  * \param[in] key       initial value/state for algorithm, if \a key = NULL
 190  *                      use default initial value
 191  * \param[in] key_len   length of \a key in bytes
 192  *
 193  * \retval              pointer to descriptor of hash instance
 194  * \retval              ERR_PTR(errno) in case of error
 195  */
 196 struct cfs_crypto_hash_desc *
 197 cfs_crypto_hash_init(enum cfs_crypto_hash_alg hash_alg,
 198                      unsigned char *key, unsigned int key_len)
 199 {
 200         struct ahash_request *req;
 201         int                  err;
 202         const struct cfs_crypto_hash_type       *type;
 203
 204         err = cfs_crypto_hash_alloc(hash_alg, &type, &req, key, key_len);
 205
 206         if (err)
 207                 return ERR_PTR(err);
 208         return (struct cfs_crypto_hash_desc *)req;
 209 }
 210 EXPORT_SYMBOL(cfs_crypto_hash_init);
 211
 212 /**
 213  * Update hash digest computed on data within the given \a page
 214  *
 215  * \param[in] hdesc     hash state descriptor
 216  * \param[in] page      data page on which to compute the hash
 217  * \param[in] offset    offset within \a page at which to start hash
 218  * \param[in] len       length of data on which to compute hash
 219  *
 220  * \retval              0 for success
 221  * \retval              negative errno on failure
 222  */
 223 int cfs_crypto_hash_update_page(struct cfs_crypto_hash_desc *hdesc,
 224                                 struct page *page, unsigned int offset,
 225                                 unsigned int len)
 226 {
 227         struct ahash_request *req = (void *)hdesc;
 228         struct scatterlist sl;
 229
 230         sg_init_table(&sl, 1);
 231         sg_set_page(&sl, page, len, offset & ~PAGE_MASK);
 232
 233         ahash_request_set_crypt(req, &sl, NULL, sl.length);
 234         return crypto_ahash_update(req);
 235 }
 236 EXPORT_SYMBOL(cfs_crypto_hash_update_page);
 237
 238 /**
 239  * Update hash digest computed on the specified data
 240  *
 241  * \param[in] hdesc     hash state descriptor
 242  * \param[in] buf       data buffer on which to compute the hash
 243  * \param[in] buf_len   length of \buf on which to compute hash
 244  *
 245  * \retval              0 for success
 246  * \retval              negative errno on failure
 247  */
 248 int cfs_crypto_hash_update(struct cfs_crypto_hash_desc *hdesc,
 249                            const void *buf, unsigned int buf_len)
 250 {
 251         struct ahash_request *req = (void *)hdesc;
 252         struct scatterlist sl;
 253
 254         sg_init_one(&sl, buf, buf_len);
 255
 256         ahash_request_set_crypt(req, &sl, NULL, sl.length);
 257         return crypto_ahash_update(req);
 258 }
 259 EXPORT_SYMBOL(cfs_crypto_hash_update);
 260
 261 /**
 262  * Finish hash calculation, copy hash digest to buffer, clean up hash descriptor
 263  *
 264  * \param[in]     hdesc         hash descriptor
 265  * \param[out]    hash          pointer to hash buffer to store hash digest
 266  * \param[in,out] hash_len      pointer to hash buffer size, if \a hdesc = NULL
 267  *                              only free \a hdesc instead of computing the hash
 268  *
 269  * \retval      0 for success
 270  * \retval      -EOVERFLOW if hash_len is too small for the hash digest
 271  * \retval      negative errno for other errors from lower layers
 272  */
 273 int cfs_crypto_hash_final(struct cfs_crypto_hash_desc *hdesc,
 274                           unsigned char *hash, unsigned int *hash_len)
 275 {
 276         int     err;
 277         struct ahash_request *req = (void *)hdesc;
 278         int size = crypto_ahash_digestsize(crypto_ahash_reqtfm(req));
 279
 280         if (!hash || !hash_len) {
 281                 err = 0;
 282                 goto free_ahash;
 283         }
 284         if (*hash_len < size) {
 285                 err = -EOVERFLOW;
 286                 goto free_ahash;
 287         }
 288
 289         ahash_request_set_crypt(req, NULL, hash, 0);
 290         err = crypto_ahash_final(req);
 291         if (!err)
 292                 *hash_len = size;
 293 free_ahash:
 294         crypto_free_ahash(crypto_ahash_reqtfm(req));
 295         ahash_request_free(req);
 296         return err;
 297 }
 298 EXPORT_SYMBOL(cfs_crypto_hash_final);
 299
 300 /**
 301  * Compute the speed of specified hash function
 302  *
 303  * Run a speed test on the given hash algorithm on buffer of the given size.
 304  * The speed is stored internally in the cfs_crypto_hash_speeds[] array, and
 305  * is available through the cfs_crypto_hash_speed() function.
 306  *
 307  * \param[in] hash_alg  hash algorithm id (CFS_HASH_ALG_*)
 308  * \param[in] buf       data buffer on which to compute the hash
 309  * \param[in] buf_len   length of \buf on which to compute hash
 310  */
 311 static void cfs_crypto_performance_test(enum cfs_crypto_hash_alg hash_alg)
 312 {
 313         int buf_len = max(PAGE_SIZE, 1048576UL);
 314         void *buf;
 315         unsigned long              start, end;
 316         int                          bcount, err = 0;
 317         struct page *page;
 318         unsigned char hash[CFS_CRYPTO_HASH_DIGESTSIZE_MAX];
 319         unsigned int hash_len = sizeof(hash);
 320
 321         page = alloc_page(GFP_KERNEL);
 322         if (!page) {
 323                 err = -ENOMEM;
 324                 goto out_err;
 325         }
 326
 327         buf = kmap(page);
 328         memset(buf, 0xAD, PAGE_SIZE);
 329         kunmap(page);
 330
 331         for (start = jiffies, end = start + msecs_to_jiffies(MSEC_PER_SEC),
 332              bcount = 0; time_before(jiffies, end); bcount++) {
 333                 struct cfs_crypto_hash_desc *hdesc;
 334                 int i;
 335
 336                 hdesc = cfs_crypto_hash_init(hash_alg, NULL, 0);
 337                 if (IS_ERR(hdesc)) {
 338                         err = PTR_ERR(hdesc);
 339                         break;
 340                 }
 341
 342                 for (i = 0; i < buf_len / PAGE_SIZE; i++) {
 343                         err = cfs_crypto_hash_update_page(hdesc, page, 0,
 344                                                           PAGE_SIZE);
 345                         if (err)
 346                                 break;
 347                 }
 348
 349                 err = cfs_crypto_hash_final(hdesc, hash, &hash_len);
 350                 if (err)
 351                         break;
 352         }
 353         end = jiffies;
 354         __free_page(page);
 355 out_err:
 356         if (err) {
 357                 cfs_crypto_hash_speeds[hash_alg] = err;
 358                 CDEBUG(D_INFO, "Crypto hash algorithm %s test error: rc = %d\n",
 359                        cfs_crypto_hash_name(hash_alg), err);
 360         } else {
 361                 unsigned long   tmp;
 362
 363                 tmp = ((bcount * buf_len / jiffies_to_msecs(end - start)) *
 364                        1000) / (1024 * 1024);
 365                 cfs_crypto_hash_speeds[hash_alg] = (int)tmp;
 366                 CDEBUG(D_CONFIG, "Crypto hash algorithm %s speed = %d MB/s\n",
 367                        cfs_crypto_hash_name(hash_alg),
 368                        cfs_crypto_hash_speeds[hash_alg]);
 369         }
 370 }
 371
 372 /**
 373  * hash speed in Mbytes per second for valid hash algorithm
 374  *
 375  * Return the performance of the specified \a hash_alg that was previously
 376  * computed using cfs_crypto_performance_test().
 377  *
 378  * \param[in] hash_alg  hash algorithm id (CFS_HASH_ALG_*)
 379  *
 380  * \retval              positive speed of the hash function in MB/s
 381  * \retval              -ENOENT if \a hash_alg is unsupported
 382  * \retval              negative errno if \a hash_alg speed is unavailable
 383  */
 384 int cfs_crypto_hash_speed(enum cfs_crypto_hash_alg hash_alg)
 385 {
 386         if (hash_alg < CFS_HASH_ALG_MAX)
 387                 return cfs_crypto_hash_speeds[hash_alg];
 388         return -ENOENT;
 389 }
 390 EXPORT_SYMBOL(cfs_crypto_hash_speed);
 391
 392 /**
 393  * Run the performance test for all hash algorithms.
 394  *
 395  * Run the cfs_crypto_performance_test() benchmark for all of the available
 396  * hash functions using a 1MB buffer size.  This is a reasonable buffer size
 397  * for Lustre RPCs, even if the actual RPC size is larger or smaller.
 398  *
 399  * Since the setup cost and computation speed of various hash algorithms is
 400  * a function of the buffer size (and possibly internal contention of offload
 401  * engines), this speed only represents an estimate of the actual speed under
 402  * actual usage, but is reasonable for comparing available algorithms.
 403  *
 404  * The actual speeds are available via cfs_crypto_hash_speed() for later
 405  * comparison.
 406  *
 407  * \retval      0 on success
 408  * \retval      -ENOMEM if no memory is available for test buffer
 409  */
 410 static int cfs_crypto_test_hashes(void)
 411 {
 412         enum cfs_crypto_hash_alg hash_alg;
 413
 414         for (hash_alg = 0; hash_alg < CFS_HASH_ALG_MAX; hash_alg++)
 415                 cfs_crypto_performance_test(hash_alg);
 416
 417         return 0;
 418 }
 419
 420 static int adler32;
 421
 422 /**
 423  * Register available hash functions
 424  *
 425  * \retval      0
 426  */
 427 int cfs_crypto_register(void)
 428 {
 429         request_module("crc32c");
 430
 431         adler32 = cfs_crypto_adler32_register();
 432
 433         /* check all algorithms and do performance test */
 434         cfs_crypto_test_hashes();
 435         return 0;
 436 }
 437
 438 /**
 439  * Unregister previously registered hash functions
 440  */
 441 void cfs_crypto_unregister(void)
 442 {
 443         if (adler32 == 0)
 444                 cfs_crypto_adler32_unregister();
 445 }