crypto/openssl-0.9.7e/crypto/bio/bss_bio.c

   1 /* crypto/bio/bss_bio.c  -*- Mode: C; c-file-style: "eay" -*- */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55
  56 /* Special method for a BIO where the other endpoint is also a BIO
  57  * of this kind, handled by the same thread (i.e. the "peer" is actually
  58  * ourselves, wearing a different hat).
  59  * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces
  60  * for which no specific BIO method is available.
  61  * See ssl/ssltest.c for some hints on how this can be used. */
  62
  63 /* BIO_DEBUG implies BIO_PAIR_DEBUG */
  64 #ifdef BIO_DEBUG
  65 # ifndef BIO_PAIR_DEBUG
  66 #  define BIO_PAIR_DEBUG
  67 # endif
  68 #endif
  69
  70 /* disable assert() unless BIO_PAIR_DEBUG has been defined */
  71 #ifndef BIO_PAIR_DEBUG
  72 # ifndef NDEBUG
  73 #  define NDEBUG
  74 # endif
  75 #endif
  76
  77 #include <assert.h>
  78 #include <limits.h>
  79 #include <stdlib.h>
  80 #include <string.h>
  81
  82 #include <openssl/bio.h>
  83 #include <openssl/err.h>
  84 #include <openssl/crypto.h>
  85
  86 #include "e_os.h"
  87
  88 /* VxWorks defines SSIZE_MAX with an empty value causing compile errors */
  89 #if defined(OPENSSL_SYS_VXWORKS)
  90 # undef SSIZE_MAX
  91 #endif
  92 #ifndef SSIZE_MAX
  93 # define SSIZE_MAX INT_MAX
  94 #endif
  95
  96 static int bio_new(BIO *bio);
  97 static int bio_free(BIO *bio);
  98 static int bio_read(BIO *bio, char *buf, int size);
  99 static int bio_write(BIO *bio, const char *buf, int num);
 100 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr);
 101 static int bio_puts(BIO *bio, const char *str);
 102
 103 static int bio_make_pair(BIO *bio1, BIO *bio2);
 104 static void bio_destroy_pair(BIO *bio);
 105
 106 static BIO_METHOD methods_biop =
 107 {
 108         BIO_TYPE_BIO,
 109         "BIO pair",
 110         bio_write,
 111         bio_read,
 112         bio_puts,
 113         NULL /* no bio_gets */,
 114         bio_ctrl,
 115         bio_new,
 116         bio_free,
 117         NULL /* no bio_callback_ctrl */
 118 };
 119
 120 BIO_METHOD *BIO_s_bio(void)
 121         {
 122         return &methods_biop;
 123         }
 124
 125 struct bio_bio_st
 126 {
 127         BIO *peer;     /* NULL if buf == NULL.
 128                         * If peer != NULL, then peer->ptr is also a bio_bio_st,
 129                         * and its "peer" member points back to us.
 130                         * peer != NULL iff init != 0 in the BIO. */
 131
 132         /* This is for what we write (i.e. reading uses peer's struct): */
 133         int closed;     /* valid iff peer != NULL */
 134         size_t len;     /* valid iff buf != NULL; 0 if peer == NULL */
 135         size_t offset;  /* valid iff buf != NULL; 0 if len == 0 */
 136         size_t size;
 137         char *buf;      /* "size" elements (if != NULL) */
 138
 139         size_t request; /* valid iff peer != NULL; 0 if len != 0,
 140                          * otherwise set by peer to number of bytes
 141                          * it (unsuccessfully) tried to read,
 142                          * never more than buffer space (size-len) warrants. */
 143 };
 144
 145 static int bio_new(BIO *bio)
 146         {
 147         struct bio_bio_st *b;
 148
 149         b = OPENSSL_malloc(sizeof *b);
 150         if (b == NULL)
 151                 return 0;
 152
 153         b->peer = NULL;
 154         b->size = 17*1024; /* enough for one TLS record (just a default) */
 155         b->buf = NULL;
 156
 157         bio->ptr = b;
 158         return 1;
 159         }
 160
 161
 162 static int bio_free(BIO *bio)
 163         {
 164         struct bio_bio_st *b;
 165
 166         if (bio == NULL)
 167                 return 0;
 168         b = bio->ptr;
 169
 170         assert(b != NULL);
 171
 172         if (b->peer)
 173                 bio_destroy_pair(bio);
 174
 175         if (b->buf != NULL)
 176                 {
 177                 OPENSSL_free(b->buf);
 178                 }
 179
 180         OPENSSL_free(b);
 181
 182         return 1;
 183         }
 184
 185
 186
 187 static int bio_read(BIO *bio, char *buf, int size_)
 188         {
 189         size_t size = size_;
 190         size_t rest;
 191         struct bio_bio_st *b, *peer_b;
 192
 193         BIO_clear_retry_flags(bio);
 194
 195         if (!bio->init)
 196                 return 0;
 197
 198         b = bio->ptr;
 199         assert(b != NULL);
 200         assert(b->peer != NULL);
 201         peer_b = b->peer->ptr;
 202         assert(peer_b != NULL);
 203         assert(peer_b->buf != NULL);
 204
 205         peer_b->request = 0; /* will be set in "retry_read" situation */
 206
 207         if (buf == NULL || size == 0)
 208                 return 0;
 209
 210         if (peer_b->len == 0)
 211                 {
 212                 if (peer_b->closed)
 213                         return 0; /* writer has closed, and no data is left */
 214                 else
 215                         {
 216                         BIO_set_retry_read(bio); /* buffer is empty */
 217                         if (size <= peer_b->size)
 218                                 peer_b->request = size;
 219                         else
 220                                 /* don't ask for more than the peer can
 221                                  * deliver in one write */
 222                                 peer_b->request = peer_b->size;
 223                         return -1;
 224                         }
 225                 }
 226
 227         /* we can read */
 228         if (peer_b->len < size)
 229                 size = peer_b->len;
 230
 231         /* now read "size" bytes */
 232
 233         rest = size;
 234
 235         assert(rest > 0);
 236         do /* one or two iterations */
 237                 {
 238                 size_t chunk;
 239
 240                 assert(rest <= peer_b->len);
 241                 if (peer_b->offset + rest <= peer_b->size)
 242                         chunk = rest;
 243                 else
 244                         /* wrap around ring buffer */
 245                         chunk = peer_b->size - peer_b->offset;
 246                 assert(peer_b->offset + chunk <= peer_b->size);
 247
 248                 memcpy(buf, peer_b->buf + peer_b->offset, chunk);
 249
 250                 peer_b->len -= chunk;
 251                 if (peer_b->len)
 252                         {
 253                         peer_b->offset += chunk;
 254                         assert(peer_b->offset <= peer_b->size);
 255                         if (peer_b->offset == peer_b->size)
 256                                 peer_b->offset = 0;
 257                         buf += chunk;
 258                         }
 259                 else
 260                         {
 261                         /* buffer now empty, no need to advance "buf" */
 262                         assert(chunk == rest);
 263                         peer_b->offset = 0;
 264                         }
 265                 rest -= chunk;
 266                 }
 267         while (rest);
 268
 269         return size;
 270         }
 271
 272 /* non-copying interface: provide pointer to available data in buffer
 273  *    bio_nread0:  return number of available bytes
 274  *    bio_nread:   also advance index
 275  * (example usage:  bio_nread0(), read from buffer, bio_nread()
 276  *  or just         bio_nread(), read from buffer)
 277  */
 278 /* WARNING: The non-copying interface is largely untested as of yet
 279  * and may contain bugs. */
 280 static ssize_t bio_nread0(BIO *bio, char **buf)
 281         {
 282         struct bio_bio_st *b, *peer_b;
 283         ssize_t num;
 284
 285         BIO_clear_retry_flags(bio);
 286
 287         if (!bio->init)
 288                 return 0;
 289
 290         b = bio->ptr;
 291         assert(b != NULL);
 292         assert(b->peer != NULL);
 293         peer_b = b->peer->ptr;
 294         assert(peer_b != NULL);
 295         assert(peer_b->buf != NULL);
 296
 297         peer_b->request = 0;
 298
 299         if (peer_b->len == 0)
 300                 {
 301                 char dummy;
 302
 303                 /* avoid code duplication -- nothing available for reading */
 304                 return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
 305                 }
 306
 307         num = peer_b->len;
 308         if (peer_b->size < peer_b->offset + num)
 309                 /* no ring buffer wrap-around for non-copying interface */
 310                 num = peer_b->size - peer_b->offset;
 311         assert(num > 0);
 312
 313         if (buf != NULL)
 314                 *buf = peer_b->buf + peer_b->offset;
 315         return num;
 316         }
 317
 318 static ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
 319         {
 320         struct bio_bio_st *b, *peer_b;
 321         ssize_t num, available;
 322
 323         if (num_ > SSIZE_MAX)
 324                 num = SSIZE_MAX;
 325         else
 326                 num = (ssize_t)num_;
 327
 328         available = bio_nread0(bio, buf);
 329         if (num > available)
 330                 num = available;
 331         if (num <= 0)
 332                 return num;
 333
 334         b = bio->ptr;
 335         peer_b = b->peer->ptr;
 336
 337         peer_b->len -= num;
 338         if (peer_b->len)
 339                 {
 340                 peer_b->offset += num;
 341                 assert(peer_b->offset <= peer_b->size);
 342                 if (peer_b->offset == peer_b->size)
 343                         peer_b->offset = 0;
 344                 }
 345         else
 346                 peer_b->offset = 0;
 347
 348         return num;
 349         }
 350
 351
 352 static int bio_write(BIO *bio, const char *buf, int num_)
 353         {
 354         size_t num = num_;
 355         size_t rest;
 356         struct bio_bio_st *b;
 357
 358         BIO_clear_retry_flags(bio);
 359
 360         if (!bio->init || buf == NULL || num == 0)
 361                 return 0;
 362
 363         b = bio->ptr;
 364         assert(b != NULL);
 365         assert(b->peer != NULL);
 366         assert(b->buf != NULL);
 367
 368         b->request = 0;
 369         if (b->closed)
 370                 {
 371                 /* we already closed */
 372                 BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
 373                 return -1;
 374                 }
 375
 376         assert(b->len <= b->size);
 377
 378         if (b->len == b->size)
 379                 {
 380                 BIO_set_retry_write(bio); /* buffer is full */
 381                 return -1;
 382                 }
 383
 384         /* we can write */
 385         if (num > b->size - b->len)
 386                 num = b->size - b->len;
 387
 388         /* now write "num" bytes */
 389
 390         rest = num;
 391
 392         assert(rest > 0);
 393         do /* one or two iterations */
 394                 {
 395                 size_t write_offset;
 396                 size_t chunk;
 397
 398                 assert(b->len + rest <= b->size);
 399
 400                 write_offset = b->offset + b->len;
 401                 if (write_offset >= b->size)
 402                         write_offset -= b->size;
 403                 /* b->buf[write_offset] is the first byte we can write to. */
 404
 405                 if (write_offset + rest <= b->size)
 406                         chunk = rest;
 407                 else
 408                         /* wrap around ring buffer */
 409                         chunk = b->size - write_offset;
 410
 411                 memcpy(b->buf + write_offset, buf, chunk);
 412
 413                 b->len += chunk;
 414
 415                 assert(b->len <= b->size);
 416
 417                 rest -= chunk;
 418                 buf += chunk;
 419                 }
 420         while (rest);
 421
 422         return num;
 423         }
 424
 425 /* non-copying interface: provide pointer to region to write to
 426  *   bio_nwrite0:  check how much space is available
 427  *   bio_nwrite:   also increase length
 428  * (example usage:  bio_nwrite0(), write to buffer, bio_nwrite()
 429  *  or just         bio_nwrite(), write to buffer)
 430  */
 431 static ssize_t bio_nwrite0(BIO *bio, char **buf)
 432         {
 433         struct bio_bio_st *b;
 434         size_t num;
 435         size_t write_offset;
 436
 437         BIO_clear_retry_flags(bio);
 438
 439         if (!bio->init)
 440                 return 0;
 441
 442         b = bio->ptr;
 443         assert(b != NULL);
 444         assert(b->peer != NULL);
 445         assert(b->buf != NULL);
 446
 447         b->request = 0;
 448         if (b->closed)
 449                 {
 450                 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
 451                 return -1;
 452                 }
 453
 454         assert(b->len <= b->size);
 455
 456         if (b->len == b->size)
 457                 {
 458                 BIO_set_retry_write(bio);
 459                 return -1;
 460                 }
 461
 462         num = b->size - b->len;
 463         write_offset = b->offset + b->len;
 464         if (write_offset >= b->size)
 465                 write_offset -= b->size;
 466         if (write_offset + num > b->size)
 467                 /* no ring buffer wrap-around for non-copying interface
 468                  * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
 469                  * BIO_nwrite may have to be called twice) */
 470                 num = b->size - write_offset;
 471
 472         if (buf != NULL)
 473                 *buf = b->buf + write_offset;
 474         assert(write_offset + num <= b->size);
 475
 476         return num;
 477         }
 478
 479 static ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
 480         {
 481         struct bio_bio_st *b;
 482         ssize_t num, space;
 483
 484         if (num_ > SSIZE_MAX)
 485                 num = SSIZE_MAX;
 486         else
 487                 num = (ssize_t)num_;
 488
 489         space = bio_nwrite0(bio, buf);
 490         if (num > space)
 491                 num = space;
 492         if (num <= 0)
 493                 return num;
 494         b = bio->ptr;
 495         assert(b != NULL);
 496         b->len += num;
 497         assert(b->len <= b->size);
 498
 499         return num;
 500         }
 501
 502
 503 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
 504         {
 505         long ret;
 506         struct bio_bio_st *b = bio->ptr;
 507
 508         assert(b != NULL);
 509
 510         switch (cmd)
 511                 {
 512         /* specific CTRL codes */
 513
 514         case BIO_C_SET_WRITE_BUF_SIZE:
 515                 if (b->peer)
 516                         {
 517                         BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
 518                         ret = 0;
 519                         }
 520                 else if (num == 0)
 521                         {
 522                         BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
 523                         ret = 0;
 524                         }
 525                 else
 526                         {
 527                         size_t new_size = num;
 528
 529                         if (b->size != new_size)
 530                                 {
 531                                 if (b->buf)
 532                                         {
 533                                         OPENSSL_free(b->buf);
 534                                         b->buf = NULL;
 535                                         }
 536                                 b->size = new_size;
 537                                 }
 538                         ret = 1;
 539                         }
 540                 break;
 541
 542         case BIO_C_GET_WRITE_BUF_SIZE:
 543                 ret = (long) b->size;
 544                 break;
 545
 546         case BIO_C_MAKE_BIO_PAIR:
 547                 {
 548                 BIO *other_bio = ptr;
 549
 550                 if (bio_make_pair(bio, other_bio))
 551                         ret = 1;
 552                 else
 553                         ret = 0;
 554                 }
 555                 break;
 556
 557         case BIO_C_DESTROY_BIO_PAIR:
 558                 /* Affects both BIOs in the pair -- call just once!
 559                  * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
 560                 bio_destroy_pair(bio);
 561                 ret = 1;
 562                 break;
 563
 564         case BIO_C_GET_WRITE_GUARANTEE:
 565                 /* How many bytes can the caller feed to the next write
 566                  * without having to keep any? */
 567                 if (b->peer == NULL || b->closed)
 568                         ret = 0;
 569                 else
 570                         ret = (long) b->size - b->len;
 571                 break;
 572
 573         case BIO_C_GET_READ_REQUEST:
 574                 /* If the peer unsuccessfully tried to read, how many bytes
 575                  * were requested?  (As with BIO_CTRL_PENDING, that number
 576                  * can usually be treated as boolean.) */
 577                 ret = (long) b->request;
 578                 break;
 579
 580         case BIO_C_RESET_READ_REQUEST:
 581                 /* Reset request.  (Can be useful after read attempts
 582                  * at the other side that are meant to be non-blocking,
 583                  * e.g. when probing SSL_read to see if any data is
 584                  * available.) */
 585                 b->request = 0;
 586                 ret = 1;
 587                 break;
 588
 589         case BIO_C_SHUTDOWN_WR:
 590                 /* similar to shutdown(..., SHUT_WR) */
 591                 b->closed = 1;
 592                 ret = 1;
 593                 break;
 594
 595         case BIO_C_NREAD0:
 596                 /* prepare for non-copying read */
 597                 ret = (long) bio_nread0(bio, ptr);
 598                 break;
 599
 600         case BIO_C_NREAD:
 601                 /* non-copying read */
 602                 ret = (long) bio_nread(bio, ptr, (size_t) num);
 603                 break;
 604
 605         case BIO_C_NWRITE0:
 606                 /* prepare for non-copying write */
 607                 ret = (long) bio_nwrite0(bio, ptr);
 608                 break;
 609
 610         case BIO_C_NWRITE:
 611                 /* non-copying write */
 612                 ret = (long) bio_nwrite(bio, ptr, (size_t) num);
 613                 break;
 614
 615
 616         /* standard CTRL codes follow */
 617
 618         case BIO_CTRL_RESET:
 619                 if (b->buf != NULL)
 620                         {
 621                         b->len = 0;
 622                         b->offset = 0;
 623                         }
 624                 ret = 0;
 625                 break;
 626
 627         case BIO_CTRL_GET_CLOSE:
 628                 ret = bio->shutdown;
 629                 break;
 630
 631         case BIO_CTRL_SET_CLOSE:
 632                 bio->shutdown = (int) num;
 633                 ret = 1;
 634                 break;
 635
 636         case BIO_CTRL_PENDING:
 637                 if (b->peer != NULL)
 638                         {
 639                         struct bio_bio_st *peer_b = b->peer->ptr;
 640
 641                         ret = (long) peer_b->len;
 642                         }
 643                 else
 644                         ret = 0;
 645                 break;
 646
 647         case BIO_CTRL_WPENDING:
 648                 if (b->buf != NULL)
 649                         ret = (long) b->len;
 650                 else
 651                         ret = 0;
 652                 break;
 653
 654         case BIO_CTRL_DUP:
 655                 /* See BIO_dup_chain for circumstances we have to expect. */
 656                 {
 657                 BIO *other_bio = ptr;
 658                 struct bio_bio_st *other_b;
 659
 660                 assert(other_bio != NULL);
 661                 other_b = other_bio->ptr;
 662                 assert(other_b != NULL);
 663
 664                 assert(other_b->buf == NULL); /* other_bio is always fresh */
 665
 666                 other_b->size = b->size;
 667                 }
 668
 669                 ret = 1;
 670                 break;
 671
 672         case BIO_CTRL_FLUSH:
 673                 ret = 1;
 674                 break;
 675
 676         case BIO_CTRL_EOF:
 677                 {
 678                 BIO *other_bio = ptr;
 679
 680                 if (other_bio)
 681                         {
 682                         struct bio_bio_st *other_b = other_bio->ptr;
 683
 684                         assert(other_b != NULL);
 685                         ret = other_b->len == 0 && other_b->closed;
 686                         }
 687                 else
 688                         ret = 1;
 689                 }
 690                 break;
 691
 692         default:
 693                 ret = 0;
 694                 }
 695         return ret;
 696         }
 697
 698 static int bio_puts(BIO *bio, const char *str)
 699         {
 700         return bio_write(bio, str, strlen(str));
 701         }
 702
 703
 704 static int bio_make_pair(BIO *bio1, BIO *bio2)
 705         {
 706         struct bio_bio_st *b1, *b2;
 707
 708         assert(bio1 != NULL);
 709         assert(bio2 != NULL);
 710
 711         b1 = bio1->ptr;
 712         b2 = bio2->ptr;
 713
 714         if (b1->peer != NULL || b2->peer != NULL)
 715                 {
 716                 BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
 717                 return 0;
 718                 }
 719
 720         if (b1->buf == NULL)
 721                 {
 722                 b1->buf = OPENSSL_malloc(b1->size);
 723                 if (b1->buf == NULL)
 724                         {
 725                         BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
 726                         return 0;
 727                         }
 728                 b1->len = 0;
 729                 b1->offset = 0;
 730                 }
 731
 732         if (b2->buf == NULL)
 733                 {
 734                 b2->buf = OPENSSL_malloc(b2->size);
 735                 if (b2->buf == NULL)
 736                         {
 737                         BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
 738                         return 0;
 739                         }
 740                 b2->len = 0;
 741                 b2->offset = 0;
 742                 }
 743
 744         b1->peer = bio2;
 745         b1->closed = 0;
 746         b1->request = 0;
 747         b2->peer = bio1;
 748         b2->closed = 0;
 749         b2->request = 0;
 750
 751         bio1->init = 1;
 752         bio2->init = 1;
 753
 754         return 1;
 755         }
 756
 757 static void bio_destroy_pair(BIO *bio)
 758         {
 759         struct bio_bio_st *b = bio->ptr;
 760
 761         if (b != NULL)
 762                 {
 763                 BIO *peer_bio = b->peer;
 764
 765                 if (peer_bio != NULL)
 766                         {
 767                         struct bio_bio_st *peer_b = peer_bio->ptr;
 768
 769                         assert(peer_b != NULL);
 770                         assert(peer_b->peer == bio);
 771
 772                         peer_b->peer = NULL;
 773                         peer_bio->init = 0;
 774                         assert(peer_b->buf != NULL);
 775                         peer_b->len = 0;
 776                         peer_b->offset = 0;
 777
 778                         b->peer = NULL;
 779                         bio->init = 0;
 780                         assert(b->buf != NULL);
 781                         b->len = 0;
 782                         b->offset = 0;
 783                         }
 784                 }
 785         }
 786
 787
 788 /* Exported convenience functions */
 789 int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
 790         BIO **bio2_p, size_t writebuf2)
 791          {
 792          BIO *bio1 = NULL, *bio2 = NULL;
 793          long r;
 794          int ret = 0;
 795
 796          bio1 = BIO_new(BIO_s_bio());
 797          if (bio1 == NULL)
 798                  goto err;
 799          bio2 = BIO_new(BIO_s_bio());
 800          if (bio2 == NULL)
 801                  goto err;
 802
 803          if (writebuf1)
 804                  {
 805                  r = BIO_set_write_buf_size(bio1, writebuf1);
 806                  if (!r)
 807                          goto err;
 808                  }
 809          if (writebuf2)
 810                  {
 811                  r = BIO_set_write_buf_size(bio2, writebuf2);
 812                  if (!r)
 813                          goto err;
 814                  }
 815
 816          r = BIO_make_bio_pair(bio1, bio2);
 817          if (!r)
 818                  goto err;
 819          ret = 1;
 820
 821  err:
 822          if (ret == 0)
 823                  {
 824                  if (bio1)
 825                          {
 826                          BIO_free(bio1);
 827                          bio1 = NULL;
 828                          }
 829                  if (bio2)
 830                          {
 831                          BIO_free(bio2);
 832                          bio2 = NULL;
 833                          }
 834                  }
 835
 836          *bio1_p = bio1;
 837          *bio2_p = bio2;
 838          return ret;
 839          }
 840
 841 size_t BIO_ctrl_get_write_guarantee(BIO *bio)
 842         {
 843         return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
 844         }
 845
 846 size_t BIO_ctrl_get_read_request(BIO *bio)
 847         {
 848         return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
 849         }
 850
 851 int BIO_ctrl_reset_read_request(BIO *bio)
 852         {
 853         return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
 854         }
 855
 856
 857 /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
 858  * (conceivably some other BIOs could allow non-copying reads and writes too.)
 859  */
 860 int BIO_nread0(BIO *bio, char **buf)
 861         {
 862         long ret;
 863
 864         if (!bio->init)
 865                 {
 866                 BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
 867                 return -2;
 868                 }
 869
 870         ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
 871         if (ret > INT_MAX)
 872                 return INT_MAX;
 873         else
 874                 return (int) ret;
 875         }
 876
 877 int BIO_nread(BIO *bio, char **buf, int num)
 878         {
 879         int ret;
 880
 881         if (!bio->init)
 882                 {
 883                 BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
 884                 return -2;
 885                 }
 886
 887         ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
 888         if (ret > 0)
 889                 bio->num_read += ret;
 890         return ret;
 891         }
 892
 893 int BIO_nwrite0(BIO *bio, char **buf)
 894         {
 895         long ret;
 896
 897         if (!bio->init)
 898                 {
 899                 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
 900                 return -2;
 901                 }
 902
 903         ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
 904         if (ret > INT_MAX)
 905                 return INT_MAX;
 906         else
 907                 return (int) ret;
 908         }
 909
 910 int BIO_nwrite(BIO *bio, char **buf, int num)
 911         {
 912         int ret;
 913
 914         if (!bio->init)
 915                 {
 916                 BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
 917                 return -2;
 918                 }
 919
 920         ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
 921         if (ret > 0)
 922                 bio->num_read += ret;
 923         return ret;
 924         }