security/integrity/ima/ima_crypto.c

   1 /*
   2  * Copyright (C) 2005,2006,2007,2008 IBM Corporation
   3  *
   4  * Authors:
   5  * Mimi Zohar <zohar@us.ibm.com>
   6  * Kylene Hall <kjhall@us.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, version 2 of the License.
  11  *
  12  * File: ima_crypto.c
  13  *      Calculates md5/sha1 file hash, template hash, boot-aggreate hash
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/kernel.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/ratelimit.h>
  21 #include <linux/file.h>
  22 #include <linux/crypto.h>
  23 #include <linux/scatterlist.h>
  24 #include <linux/err.h>
  25 #include <linux/slab.h>
  26 #include <crypto/hash.h>
  27
  28 #include "ima.h"
  29
  30 struct ahash_completion {
  31         struct completion completion;
  32         int err;
  33 };
  34
  35 /* minimum file size for ahash use */
  36 static unsigned long ima_ahash_minsize;
  37 module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
  38 MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use");
  39
  40 /* default is 0 - 1 page. */
  41 static int ima_maxorder;
  42 static unsigned int ima_bufsize = PAGE_SIZE;
  43
  44 static int param_set_bufsize(const char *val, const struct kernel_param *kp)
  45 {
  46         unsigned long long size;
  47         int order;
  48
  49         size = memparse(val, NULL);
  50         order = get_order(size);
  51         if (order >= MAX_ORDER)
  52                 return -EINVAL;
  53         ima_maxorder = order;
  54         ima_bufsize = PAGE_SIZE << order;
  55         return 0;
  56 }
  57
  58 static const struct kernel_param_ops param_ops_bufsize = {
  59         .set = param_set_bufsize,
  60         .get = param_get_uint,
  61 };
  62 #define param_check_bufsize(name, p) __param_check(name, p, unsigned int)
  63
  64 module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644);
  65 MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size");
  66
  67 static struct crypto_shash *ima_shash_tfm;
  68 static struct crypto_ahash *ima_ahash_tfm;
  69
  70 int __init ima_init_crypto(void)
  71 {
  72         long rc;
  73
  74         ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
  75         if (IS_ERR(ima_shash_tfm)) {
  76                 rc = PTR_ERR(ima_shash_tfm);
  77                 pr_err("Can not allocate %s (reason: %ld)\n",
  78                        hash_algo_name[ima_hash_algo], rc);
  79                 return rc;
  80         }
  81         pr_info("Allocated hash algorithm: %s\n",
  82                 hash_algo_name[ima_hash_algo]);
  83         return 0;
  84 }
  85
  86 static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
  87 {
  88         struct crypto_shash *tfm = ima_shash_tfm;
  89         int rc;
  90
  91         if (algo < 0 || algo >= HASH_ALGO__LAST)
  92                 algo = ima_hash_algo;
  93
  94         if (algo != ima_hash_algo) {
  95                 tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
  96                 if (IS_ERR(tfm)) {
  97                         rc = PTR_ERR(tfm);
  98                         pr_err("Can not allocate %s (reason: %d)\n",
  99                                hash_algo_name[algo], rc);
 100                 }
 101         }
 102         return tfm;
 103 }
 104
 105 static void ima_free_tfm(struct crypto_shash *tfm)
 106 {
 107         if (tfm != ima_shash_tfm)
 108                 crypto_free_shash(tfm);
 109 }
 110
 111 /**
 112  * ima_alloc_pages() - Allocate contiguous pages.
 113  * @max_size:       Maximum amount of memory to allocate.
 114  * @allocated_size: Returned size of actual allocation.
 115  * @last_warn:      Should the min_size allocation warn or not.
 116  *
 117  * Tries to do opportunistic allocation for memory first trying to allocate
 118  * max_size amount of memory and then splitting that until zero order is
 119  * reached. Allocation is tried without generating allocation warnings unless
 120  * last_warn is set. Last_warn set affects only last allocation of zero order.
 121  *
 122  * By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL)
 123  *
 124  * Return pointer to allocated memory, or NULL on failure.
 125  */
 126 static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size,
 127                              int last_warn)
 128 {
 129         void *ptr;
 130         int order = ima_maxorder;
 131         gfp_t gfp_mask = __GFP_RECLAIM | __GFP_NOWARN | __GFP_NORETRY;
 132
 133         if (order)
 134                 order = min(get_order(max_size), order);
 135
 136         for (; order; order--) {
 137                 ptr = (void *)__get_free_pages(gfp_mask, order);
 138                 if (ptr) {
 139                         *allocated_size = PAGE_SIZE << order;
 140                         return ptr;
 141                 }
 142         }
 143
 144         /* order is zero - one page */
 145
 146         gfp_mask = GFP_KERNEL;
 147
 148         if (!last_warn)
 149                 gfp_mask |= __GFP_NOWARN;
 150
 151         ptr = (void *)__get_free_pages(gfp_mask, 0);
 152         if (ptr) {
 153                 *allocated_size = PAGE_SIZE;
 154                 return ptr;
 155         }
 156
 157         *allocated_size = 0;
 158         return NULL;
 159 }
 160
 161 /**
 162  * ima_free_pages() - Free pages allocated by ima_alloc_pages().
 163  * @ptr:  Pointer to allocated pages.
 164  * @size: Size of allocated buffer.
 165  */
 166 static void ima_free_pages(void *ptr, size_t size)
 167 {
 168         if (!ptr)
 169                 return;
 170         free_pages((unsigned long)ptr, get_order(size));
 171 }
 172
 173 static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo)
 174 {
 175         struct crypto_ahash *tfm = ima_ahash_tfm;
 176         int rc;
 177
 178         if (algo < 0 || algo >= HASH_ALGO__LAST)
 179                 algo = ima_hash_algo;
 180
 181         if (algo != ima_hash_algo || !tfm) {
 182                 tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0);
 183                 if (!IS_ERR(tfm)) {
 184                         if (algo == ima_hash_algo)
 185                                 ima_ahash_tfm = tfm;
 186                 } else {
 187                         rc = PTR_ERR(tfm);
 188                         pr_err("Can not allocate %s (reason: %d)\n",
 189                                hash_algo_name[algo], rc);
 190                 }
 191         }
 192         return tfm;
 193 }
 194
 195 static void ima_free_atfm(struct crypto_ahash *tfm)
 196 {
 197         if (tfm != ima_ahash_tfm)
 198                 crypto_free_ahash(tfm);
 199 }
 200
 201 static void ahash_complete(struct crypto_async_request *req, int err)
 202 {
 203         struct ahash_completion *res = req->data;
 204
 205         if (err == -EINPROGRESS)
 206                 return;
 207         res->err = err;
 208         complete(&res->completion);
 209 }
 210
 211 static int ahash_wait(int err, struct ahash_completion *res)
 212 {
 213         switch (err) {
 214         case 0:
 215                 break;
 216         case -EINPROGRESS:
 217         case -EBUSY:
 218                 wait_for_completion(&res->completion);
 219                 reinit_completion(&res->completion);
 220                 err = res->err;
 221                 /* fall through */
 222         default:
 223                 pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
 224         }
 225
 226         return err;
 227 }
 228
 229 static int ima_calc_file_hash_atfm(struct file *file,
 230                                    struct ima_digest_data *hash,
 231                                    struct crypto_ahash *tfm)
 232 {
 233         loff_t i_size, offset;
 234         char *rbuf[2] = { NULL, };
 235         int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0;
 236         struct ahash_request *req;
 237         struct scatterlist sg[1];
 238         struct ahash_completion res;
 239         size_t rbuf_size[2];
 240
 241         hash->length = crypto_ahash_digestsize(tfm);
 242
 243         req = ahash_request_alloc(tfm, GFP_KERNEL);
 244         if (!req)
 245                 return -ENOMEM;
 246
 247         init_completion(&res.completion);
 248         ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 249                                    CRYPTO_TFM_REQ_MAY_SLEEP,
 250                                    ahash_complete, &res);
 251
 252         rc = ahash_wait(crypto_ahash_init(req), &res);
 253         if (rc)
 254                 goto out1;
 255
 256         i_size = i_size_read(file_inode(file));
 257
 258         if (i_size == 0)
 259                 goto out2;
 260
 261         /*
 262          * Try to allocate maximum size of memory.
 263          * Fail if even a single page cannot be allocated.
 264          */
 265         rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1);
 266         if (!rbuf[0]) {
 267                 rc = -ENOMEM;
 268                 goto out1;
 269         }
 270
 271         /* Only allocate one buffer if that is enough. */
 272         if (i_size > rbuf_size[0]) {
 273                 /*
 274                  * Try to allocate secondary buffer. If that fails fallback to
 275                  * using single buffering. Use previous memory allocation size
 276                  * as baseline for possible allocation size.
 277                  */
 278                 rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0],
 279                                           &rbuf_size[1], 0);
 280         }
 281
 282         if (!(file->f_mode & FMODE_READ)) {
 283                 file->f_mode |= FMODE_READ;
 284                 read = 1;
 285         }
 286
 287         for (offset = 0; offset < i_size; offset += rbuf_len) {
 288                 if (!rbuf[1] && offset) {
 289                         /* Not using two buffers, and it is not the first
 290                          * read/request, wait for the completion of the
 291                          * previous ahash_update() request.
 292                          */
 293                         rc = ahash_wait(ahash_rc, &res);
 294                         if (rc)
 295                                 goto out3;
 296                 }
 297                 /* read buffer */
 298                 rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
 299                 rc = integrity_kernel_read(file, offset, rbuf[active],
 300                                            rbuf_len);
 301                 if (rc != rbuf_len) {
 302                         if (rc >= 0)
 303                                 rc = -EINVAL;
 304                         goto out3;
 305                 }
 306
 307                 if (rbuf[1] && offset) {
 308                         /* Using two buffers, and it is not the first
 309                          * read/request, wait for the completion of the
 310                          * previous ahash_update() request.
 311                          */
 312                         rc = ahash_wait(ahash_rc, &res);
 313                         if (rc)
 314                                 goto out3;
 315                 }
 316
 317                 sg_init_one(&sg[0], rbuf[active], rbuf_len);
 318                 ahash_request_set_crypt(req, sg, NULL, rbuf_len);
 319
 320                 ahash_rc = crypto_ahash_update(req);
 321
 322                 if (rbuf[1])
 323                         active = !active; /* swap buffers, if we use two */
 324         }
 325         /* wait for the last update request to complete */
 326         rc = ahash_wait(ahash_rc, &res);
 327 out3:
 328         if (read)
 329                 file->f_mode &= ~FMODE_READ;
 330         ima_free_pages(rbuf[0], rbuf_size[0]);
 331         ima_free_pages(rbuf[1], rbuf_size[1]);
 332 out2:
 333         if (!rc) {
 334                 ahash_request_set_crypt(req, NULL, hash->digest, 0);
 335                 rc = ahash_wait(crypto_ahash_final(req), &res);
 336         }
 337 out1:
 338         ahash_request_free(req);
 339         return rc;
 340 }
 341
 342 static int ima_calc_file_ahash(struct file *file, struct ima_digest_data *hash)
 343 {
 344         struct crypto_ahash *tfm;
 345         int rc;
 346
 347         tfm = ima_alloc_atfm(hash->algo);
 348         if (IS_ERR(tfm))
 349                 return PTR_ERR(tfm);
 350
 351         rc = ima_calc_file_hash_atfm(file, hash, tfm);
 352
 353         ima_free_atfm(tfm);
 354
 355         return rc;
 356 }
 357
 358 static int ima_calc_file_hash_tfm(struct file *file,
 359                                   struct ima_digest_data *hash,
 360                                   struct crypto_shash *tfm)
 361 {
 362         loff_t i_size, offset = 0;
 363         char *rbuf;
 364         int rc, read = 0;
 365         SHASH_DESC_ON_STACK(shash, tfm);
 366
 367         shash->tfm = tfm;
 368         shash->flags = 0;
 369
 370         hash->length = crypto_shash_digestsize(tfm);
 371
 372         rc = crypto_shash_init(shash);
 373         if (rc != 0)
 374                 return rc;
 375
 376         i_size = i_size_read(file_inode(file));
 377
 378         if (i_size == 0)
 379                 goto out;
 380
 381         rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 382         if (!rbuf)
 383                 return -ENOMEM;
 384
 385         if (!(file->f_mode & FMODE_READ)) {
 386                 file->f_mode |= FMODE_READ;
 387                 read = 1;
 388         }
 389
 390         while (offset < i_size) {
 391                 int rbuf_len;
 392
 393                 rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE);
 394                 if (rbuf_len < 0) {
 395                         rc = rbuf_len;
 396                         break;
 397                 }
 398                 if (rbuf_len == 0)
 399                         break;
 400                 offset += rbuf_len;
 401
 402                 rc = crypto_shash_update(shash, rbuf, rbuf_len);
 403                 if (rc)
 404                         break;
 405         }
 406         if (read)
 407                 file->f_mode &= ~FMODE_READ;
 408         kfree(rbuf);
 409 out:
 410         if (!rc)
 411                 rc = crypto_shash_final(shash, hash->digest);
 412         return rc;
 413 }
 414
 415 static int ima_calc_file_shash(struct file *file, struct ima_digest_data *hash)
 416 {
 417         struct crypto_shash *tfm;
 418         int rc;
 419
 420         tfm = ima_alloc_tfm(hash->algo);
 421         if (IS_ERR(tfm))
 422                 return PTR_ERR(tfm);
 423
 424         rc = ima_calc_file_hash_tfm(file, hash, tfm);
 425
 426         ima_free_tfm(tfm);
 427
 428         return rc;
 429 }
 430
 431 /*
 432  * ima_calc_file_hash - calculate file hash
 433  *
 434  * Asynchronous hash (ahash) allows using HW acceleration for calculating
 435  * a hash. ahash performance varies for different data sizes on different
 436  * crypto accelerators. shash performance might be better for smaller files.
 437  * The 'ima.ahash_minsize' module parameter allows specifying the best
 438  * minimum file size for using ahash on the system.
 439  *
 440  * If the ima.ahash_minsize parameter is not specified, this function uses
 441  * shash for the hash calculation.  If ahash fails, it falls back to using
 442  * shash.
 443  */
 444 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 445 {
 446         loff_t i_size;
 447         int rc;
 448
 449         /*
 450          * For consistency, fail file's opened with the O_DIRECT flag on
 451          * filesystems mounted with/without DAX option.
 452          */
 453         if (file->f_flags & O_DIRECT) {
 454                 hash->length = hash_digest_size[ima_hash_algo];
 455                 hash->algo = ima_hash_algo;
 456                 return -EINVAL;
 457         }
 458
 459         i_size = i_size_read(file_inode(file));
 460
 461         if (ima_ahash_minsize && i_size >= ima_ahash_minsize) {
 462                 rc = ima_calc_file_ahash(file, hash);
 463                 if (!rc)
 464                         return 0;
 465         }
 466
 467         return ima_calc_file_shash(file, hash);
 468 }
 469
 470 /*
 471  * Calculate the hash of template data
 472  */
 473 static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 474                                          struct ima_template_desc *td,
 475                                          int num_fields,
 476                                          struct ima_digest_data *hash,
 477                                          struct crypto_shash *tfm)
 478 {
 479         SHASH_DESC_ON_STACK(shash, tfm);
 480         int rc, i;
 481
 482         shash->tfm = tfm;
 483         shash->flags = 0;
 484
 485         hash->length = crypto_shash_digestsize(tfm);
 486
 487         rc = crypto_shash_init(shash);
 488         if (rc != 0)
 489                 return rc;
 490
 491         for (i = 0; i < num_fields; i++) {
 492                 u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
 493                 u8 *data_to_hash = field_data[i].data;
 494                 u32 datalen = field_data[i].len;
 495
 496                 if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
 497                         rc = crypto_shash_update(shash,
 498                                                 (const u8 *) &field_data[i].len,
 499                                                 sizeof(field_data[i].len));
 500                         if (rc)
 501                                 break;
 502                 } else if (strcmp(td->fields[i]->field_id, "n") == 0) {
 503                         memcpy(buffer, data_to_hash, datalen);
 504                         data_to_hash = buffer;
 505                         datalen = IMA_EVENT_NAME_LEN_MAX + 1;
 506                 }
 507                 rc = crypto_shash_update(shash, data_to_hash, datalen);
 508                 if (rc)
 509                         break;
 510         }
 511
 512         if (!rc)
 513                 rc = crypto_shash_final(shash, hash->digest);
 514
 515         return rc;
 516 }
 517
 518 int ima_calc_field_array_hash(struct ima_field_data *field_data,
 519                               struct ima_template_desc *desc, int num_fields,
 520                               struct ima_digest_data *hash)
 521 {
 522         struct crypto_shash *tfm;
 523         int rc;
 524
 525         tfm = ima_alloc_tfm(hash->algo);
 526         if (IS_ERR(tfm))
 527                 return PTR_ERR(tfm);
 528
 529         rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields,
 530                                            hash, tfm);
 531
 532         ima_free_tfm(tfm);
 533
 534         return rc;
 535 }
 536
 537 static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
 538                                   struct ima_digest_data *hash,
 539                                   struct crypto_ahash *tfm)
 540 {
 541         struct ahash_request *req;
 542         struct scatterlist sg;
 543         struct ahash_completion res;
 544         int rc, ahash_rc = 0;
 545
 546         hash->length = crypto_ahash_digestsize(tfm);
 547
 548         req = ahash_request_alloc(tfm, GFP_KERNEL);
 549         if (!req)
 550                 return -ENOMEM;
 551
 552         init_completion(&res.completion);
 553         ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 554                                    CRYPTO_TFM_REQ_MAY_SLEEP,
 555                                    ahash_complete, &res);
 556
 557         rc = ahash_wait(crypto_ahash_init(req), &res);
 558         if (rc)
 559                 goto out;
 560
 561         sg_init_one(&sg, buf, len);
 562         ahash_request_set_crypt(req, &sg, NULL, len);
 563
 564         ahash_rc = crypto_ahash_update(req);
 565
 566         /* wait for the update request to complete */
 567         rc = ahash_wait(ahash_rc, &res);
 568         if (!rc) {
 569                 ahash_request_set_crypt(req, NULL, hash->digest, 0);
 570                 rc = ahash_wait(crypto_ahash_final(req), &res);
 571         }
 572 out:
 573         ahash_request_free(req);
 574         return rc;
 575 }
 576
 577 static int calc_buffer_ahash(const void *buf, loff_t len,
 578                              struct ima_digest_data *hash)
 579 {
 580         struct crypto_ahash *tfm;
 581         int rc;
 582
 583         tfm = ima_alloc_atfm(hash->algo);
 584         if (IS_ERR(tfm))
 585                 return PTR_ERR(tfm);
 586
 587         rc = calc_buffer_ahash_atfm(buf, len, hash, tfm);
 588
 589         ima_free_atfm(tfm);
 590
 591         return rc;
 592 }
 593
 594 static int calc_buffer_shash_tfm(const void *buf, loff_t size,
 595                                 struct ima_digest_data *hash,
 596                                 struct crypto_shash *tfm)
 597 {
 598         SHASH_DESC_ON_STACK(shash, tfm);
 599         unsigned int len;
 600         int rc;
 601
 602         shash->tfm = tfm;
 603         shash->flags = 0;
 604
 605         hash->length = crypto_shash_digestsize(tfm);
 606
 607         rc = crypto_shash_init(shash);
 608         if (rc != 0)
 609                 return rc;
 610
 611         while (size) {
 612                 len = size < PAGE_SIZE ? size : PAGE_SIZE;
 613                 rc = crypto_shash_update(shash, buf, len);
 614                 if (rc)
 615                         break;
 616                 buf += len;
 617                 size -= len;
 618         }
 619
 620         if (!rc)
 621                 rc = crypto_shash_final(shash, hash->digest);
 622         return rc;
 623 }
 624
 625 static int calc_buffer_shash(const void *buf, loff_t len,
 626                              struct ima_digest_data *hash)
 627 {
 628         struct crypto_shash *tfm;
 629         int rc;
 630
 631         tfm = ima_alloc_tfm(hash->algo);
 632         if (IS_ERR(tfm))
 633                 return PTR_ERR(tfm);
 634
 635         rc = calc_buffer_shash_tfm(buf, len, hash, tfm);
 636
 637         ima_free_tfm(tfm);
 638         return rc;
 639 }
 640
 641 int ima_calc_buffer_hash(const void *buf, loff_t len,
 642                          struct ima_digest_data *hash)
 643 {
 644         int rc;
 645
 646         if (ima_ahash_minsize && len >= ima_ahash_minsize) {
 647                 rc = calc_buffer_ahash(buf, len, hash);
 648                 if (!rc)
 649                         return 0;
 650         }
 651
 652         return calc_buffer_shash(buf, len, hash);
 653 }
 654
 655 static void __init ima_pcrread(int idx, u8 *pcr)
 656 {
 657         if (!ima_used_chip)
 658                 return;
 659
 660         if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
 661                 pr_err("Error Communicating to TPM chip\n");
 662 }
 663
 664 /*
 665  * Calculate the boot aggregate hash
 666  */
 667 static int __init ima_calc_boot_aggregate_tfm(char *digest,
 668                                               struct crypto_shash *tfm)
 669 {
 670         u8 pcr_i[TPM_DIGEST_SIZE];
 671         int rc, i;
 672         SHASH_DESC_ON_STACK(shash, tfm);
 673
 674         shash->tfm = tfm;
 675         shash->flags = 0;
 676
 677         rc = crypto_shash_init(shash);
 678         if (rc != 0)
 679                 return rc;
 680
 681         /* cumulative sha1 over tpm registers 0-7 */
 682         for (i = TPM_PCR0; i < TPM_PCR8; i++) {
 683                 ima_pcrread(i, pcr_i);
 684                 /* now accumulate with current aggregate */
 685                 rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
 686         }
 687         if (!rc)
 688                 crypto_shash_final(shash, digest);
 689         return rc;
 690 }
 691
 692 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
 693 {
 694         struct crypto_shash *tfm;
 695         int rc;
 696
 697         tfm = ima_alloc_tfm(hash->algo);
 698         if (IS_ERR(tfm))
 699                 return PTR_ERR(tfm);
 700
 701         hash->length = crypto_shash_digestsize(tfm);
 702         rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);
 703
 704         ima_free_tfm(tfm);
 705
 706         return rc;
 707 }