text: /* crypto/bio/bio_lib.c */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  #include <errno.h>
  #include <openssl/crypto.h>
  #include "cryptlib.h"
  #include <openssl/bio.h>
  #include <openssl/stack.h>
  
  BIO *BIO_new(BIO_METHOD *method)
  {
      BIO *ret = NULL;
  
      ret = (BIO *)OPENSSL_malloc(sizeof(BIO));
      if (ret == NULL) {
          BIOerr(BIO_F_BIO_NEW, ERR_R_MALLOC_FAILURE);
          return (NULL);
      }
      if (!BIO_set(ret, method)) {
          OPENSSL_free(ret);
          ret = NULL;
      }
      return (ret);
  }
  
  int BIO_set(BIO *bio, BIO_METHOD *method)
  {
      bio->method = method;
      bio->callback = NULL;
      bio->cb_arg = NULL;
      bio->init = 0;
      bio->shutdown = 1;
      bio->flags = 0;
      bio->retry_reason = 0;
      bio->num = 0;
      bio->ptr = NULL;
      bio->prev_bio = NULL;
      bio->next_bio = NULL;
      bio->references = 1;
      bio->num_read = 0L;
      bio->num_write = 0L;
      CRYPTO_new_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data);
      if (method->create != NULL)
          if (!method->create(bio)) {
              CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data);
              return (0);
          }
      return (1);
  }
  
  int BIO_free(BIO *a)
  {
      int i;
  
      if (a == NULL)
          return (0);
  
      i = CRYPTO_add(&a->references, -1, CRYPTO_LOCK_BIO);
  #ifdef REF_PRINT
      REF_PRINT("BIO", a);
  #endif
      if (i > 0)
          return (1);
  #ifdef REF_CHECK
      if (i < 0) {
          fprintf(stderr, "BIO_free, bad reference count\n");
          abort();
      }
  #endif
      if ((a->callback != NULL) &&
          ((i = (int)a->callback(a, BIO_CB_FREE, NULL, 0, 0L, 1L)) <= 0))
          return (i);
  
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, a, &a->ex_data);
  
      if ((a->method != NULL) && (a->method->destroy != NULL))
          a->method->destroy(a);
      OPENSSL_free(a);
      return (1);
  }
  
  void BIO_vfree(BIO *a)
  {
      BIO_free(a);
  }
  
  void BIO_clear_flags(BIO *b, int flags)
  {
      b->flags &= ~flags;
  }
  
  int BIO_test_flags(const BIO *b, int flags)
  {
      return (b->flags & flags);
  }
  
  void BIO_set_flags(BIO *b, int flags)
  {
      b->flags |= flags;
  }
  
  long (*BIO_get_callback(const BIO *b)) (struct bio_st *, int, const char *,
                                          int, long, long) {
      return b->callback;
  }
  
  void BIO_set_callback(BIO *b,
                        long (*cb) (struct bio_st *, int, const char *, int,
                                    long, long))
  {
      b->callback = cb;
  }
  
  void BIO_set_callback_arg(BIO *b, char *arg)
  {
      b->cb_arg = arg;
  }
  
  char *BIO_get_callback_arg(const BIO *b)
  {
      return b->cb_arg;
  }
  
  const char *BIO_method_name(const BIO *b)
  {
      return b->method->name;
  }
  
  int BIO_method_type(const BIO *b)
  {
      return b->method->type;
  }
  
  int BIO_read(BIO *b, void *out, int outl)
  {
      int i;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if ((b == NULL) || (b->method == NULL) || (b->method->bread == NULL)) {
          BIOerr(BIO_F_BIO_READ, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      cb = b->callback;
      if ((cb != NULL) &&
          ((i = (int)cb(b, BIO_CB_READ, out, outl, 0L, 1L)) <= 0))
          return (i);
  
      if (!b->init) {
          BIOerr(BIO_F_BIO_READ, BIO_R_UNINITIALIZED);
          return (-2);
      }
  
      i = b->method->bread(b, out, outl);
  
      if (i > 0)
          b->num_read += (unsigned long)i;
  
      if (cb != NULL)
          i = (int)cb(b, BIO_CB_READ | BIO_CB_RETURN, out, outl, 0L, (long)i);
      return (i);
  }
  
  int BIO_write(BIO *b, const void *in, int inl)
  {
      int i;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if (b == NULL)
          return (0);
  
      cb = b->callback;
      if ((b->method == NULL) || (b->method->bwrite == NULL)) {
          BIOerr(BIO_F_BIO_WRITE, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      if ((cb != NULL) &&
          ((i = (int)cb(b, BIO_CB_WRITE, in, inl, 0L, 1L)) <= 0))
          return (i);
  
      if (!b->init) {
          BIOerr(BIO_F_BIO_WRITE, BIO_R_UNINITIALIZED);
          return (-2);
      }
  
      i = b->method->bwrite(b, in, inl);
  
      if (i > 0)
          b->num_write += (unsigned long)i;
  
      if (cb != NULL)
          i = (int)cb(b, BIO_CB_WRITE | BIO_CB_RETURN, in, inl, 0L, (long)i);
      return (i);
  }
  
  int BIO_puts(BIO *b, const char *in)
  {
      int i;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if ((b == NULL) || (b->method == NULL) || (b->method->bputs == NULL)) {
          BIOerr(BIO_F_BIO_PUTS, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      cb = b->callback;
  
      if ((cb != NULL) && ((i = (int)cb(b, BIO_CB_PUTS, in, 0, 0L, 1L)) <= 0))
          return (i);
  
      if (!b->init) {
          BIOerr(BIO_F_BIO_PUTS, BIO_R_UNINITIALIZED);
          return (-2);
      }
  
      i = b->method->bputs(b, in);
  
      if (i > 0)
          b->num_write += (unsigned long)i;
  
      if (cb != NULL)
          i = (int)cb(b, BIO_CB_PUTS | BIO_CB_RETURN, in, 0, 0L, (long)i);
      return (i);
  }
  
  int BIO_gets(BIO *b, char *in, int inl)
  {
      int i;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if ((b == NULL) || (b->method == NULL) || (b->method->bgets == NULL)) {
          BIOerr(BIO_F_BIO_GETS, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      cb = b->callback;
  
      if ((cb != NULL) && ((i = (int)cb(b, BIO_CB_GETS, in, inl, 0L, 1L)) <= 0))
          return (i);
  
      if (!b->init) {
          BIOerr(BIO_F_BIO_GETS, BIO_R_UNINITIALIZED);
          return (-2);
      }
  
      i = b->method->bgets(b, in, inl);
  
      if (cb != NULL)
          i = (int)cb(b, BIO_CB_GETS | BIO_CB_RETURN, in, inl, 0L, (long)i);
      return (i);
  }
  
  int BIO_indent(BIO *b, int indent, int max)
  {
      if (indent < 0)
          indent = 0;
      if (indent > max)
          indent = max;
      while (indent--)
          if (BIO_puts(b, " ") != 1)
              return 0;
      return 1;
  }
  
  long BIO_int_ctrl(BIO *b, int cmd, long larg, int iarg)
  {
      int i;
  
      i = iarg;
      return (BIO_ctrl(b, cmd, larg, (char *)&i));
  }
  
  char *BIO_ptr_ctrl(BIO *b, int cmd, long larg)
  {
      char *p = NULL;
  
      if (BIO_ctrl(b, cmd, larg, (char *)&p) <= 0)
          return (NULL);
      else
          return (p);
  }
  
  long BIO_ctrl(BIO *b, int cmd, long larg, void *parg)
  {
      long ret;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if (b == NULL)
          return (0);
  
      if ((b->method == NULL) || (b->method->ctrl == NULL)) {
          BIOerr(BIO_F_BIO_CTRL, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      cb = b->callback;
  
      if ((cb != NULL) &&
          ((ret = cb(b, BIO_CB_CTRL, parg, cmd, larg, 1L)) <= 0))
          return (ret);
  
      ret = b->method->ctrl(b, cmd, larg, parg);
  
      if (cb != NULL)
          ret = cb(b, BIO_CB_CTRL | BIO_CB_RETURN, parg, cmd, larg, ret);
      return (ret);
  }
  
  long BIO_callback_ctrl(BIO *b, int cmd,
                         void (*fp) (struct bio_st *, int, const char *, int,
                                     long, long))
  {
      long ret;
      long (*cb) (BIO *, int, const char *, int, long, long);
  
      if (b == NULL)
          return (0);
  
      if ((b->method == NULL) || (b->method->callback_ctrl == NULL)) {
          BIOerr(BIO_F_BIO_CALLBACK_CTRL, BIO_R_UNSUPPORTED_METHOD);
          return (-2);
      }
  
      cb = b->callback;
  
      if ((cb != NULL) &&
          ((ret = cb(b, BIO_CB_CTRL, (void *)&fp, cmd, 0, 1L)) <= 0))
          return (ret);
  
      ret = b->method->callback_ctrl(b, cmd, fp);
  
      if (cb != NULL)
          ret = cb(b, BIO_CB_CTRL | BIO_CB_RETURN, (void *)&fp, cmd, 0, ret);
      return (ret);
  }
  
  /*
   * It is unfortunate to duplicate in functions what the BIO_(w)pending macros
   * do; but those macros have inappropriate return type, and for interfacing
   * from other programming languages, C macros aren't much of a help anyway.
   */
  size_t BIO_ctrl_pending(BIO *bio)
  {
      return BIO_ctrl(bio, BIO_CTRL_PENDING, 0, NULL);
  }
  
  size_t BIO_ctrl_wpending(BIO *bio)
  {
      return BIO_ctrl(bio, BIO_CTRL_WPENDING, 0, NULL);
  }
  
  /* put the 'bio' on the end of b's list of operators */
  BIO *BIO_push(BIO *b, BIO *bio)
  {
      BIO *lb;
  
      if (b == NULL)
          return (bio);
      lb = b;
      while (lb->next_bio != NULL)
          lb = lb->next_bio;
      lb->next_bio = bio;
      if (bio != NULL)
          bio->prev_bio = lb;
      /* called to do internal processing */
      BIO_ctrl(b, BIO_CTRL_PUSH, 0, lb);
      return (b);
  }
  
  /* Remove the first and return the rest */
  BIO *BIO_pop(BIO *b)
  {
      BIO *ret;
  
      if (b == NULL)
          return (NULL);
      ret = b->next_bio;
  
      BIO_ctrl(b, BIO_CTRL_POP, 0, b);
  
      if (b->prev_bio != NULL)
          b->prev_bio->next_bio = b->next_bio;
      if (b->next_bio != NULL)
          b->next_bio->prev_bio = b->prev_bio;
  
      b->next_bio = NULL;
      b->prev_bio = NULL;
      return (ret);
  }
  
  BIO *BIO_get_retry_BIO(BIO *bio, int *reason)
  {
      BIO *b, *last;
  
      b = last = bio;
      for (;;) {
          if (!BIO_should_retry(b))
              break;
          last = b;
          b = b->next_bio;
          if (b == NULL)
              break;
      }
      if (reason != NULL)
          *reason = last->retry_reason;
      return (last);
  }
  
  int BIO_get_retry_reason(BIO *bio)
  {
      return (bio->retry_reason);
  }
  
  BIO *BIO_find_type(BIO *bio, int type)
  {
      int mt, mask;
  
      if (!bio)
          return NULL;
      mask = type & 0xff;
      do {
          if (bio->method != NULL) {
              mt = bio->method->type;
  
              if (!mask) {
                  if (mt & type)
                      return (bio);
              } else if (mt == type)
                  return (bio);
          }
          bio = bio->next_bio;
      } while (bio != NULL);
      return (NULL);
  }
  
  BIO *BIO_next(BIO *b)
  {
      if (!b)
          return NULL;
      return b->next_bio;
  }
  
  void BIO_free_all(BIO *bio)
  {
      BIO *b;
      int ref;
  
      while (bio != NULL) {
          b = bio;
          ref = b->references;
          bio = bio->next_bio;
          BIO_free(b);
          /* Since ref count > 1, don't free anyone else. */
          if (ref > 1)
              break;
      }
  }
  
  BIO *BIO_dup_chain(BIO *in)
  {
      BIO *ret = NULL, *eoc = NULL, *bio, *new_bio;
  
      for (bio = in; bio != NULL; bio = bio->next_bio) {
          if ((new_bio = BIO_new(bio->method)) == NULL)
              goto err;
          new_bio->callback = bio->callback;
          new_bio->cb_arg = bio->cb_arg;
          new_bio->init = bio->init;
          new_bio->shutdown = bio->shutdown;
          new_bio->flags = bio->flags;
  
          /* This will let SSL_s_sock() work with stdin/stdout */
          new_bio->num = bio->num;
  
          if (!BIO_dup_state(bio, (char *)new_bio)) {
              BIO_free(new_bio);
              goto err;
          }
  
          /* copy app data */
          if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_BIO, &new_bio->ex_data,
                                  &bio->ex_data)) {
              BIO_free(new_bio);
              goto err;
          }
  
          if (ret == NULL) {
              eoc = new_bio;
              ret = eoc;
          } else {
              BIO_push(eoc, new_bio);
              eoc = new_bio;
          }
      }
      return (ret);
   err:
      BIO_free_all(ret);
  
      return (NULL);
  }
  
  void BIO_copy_next_retry(BIO *b)
  {
      BIO_set_flags(b, BIO_get_retry_flags(b->next_bio));
      b->retry_reason = b->next_bio->retry_reason;
  }
  
  int BIO_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                           CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
  {
      return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_BIO, argl, argp,
                                     new_func, dup_func, free_func);
  }
  
  int BIO_set_ex_data(BIO *bio, int idx, void *data)
  {
      return (CRYPTO_set_ex_data(&(bio->ex_data), idx, data));
  }
  
  void *BIO_get_ex_data(BIO *bio, int idx)
  {
      return (CRYPTO_get_ex_data(&(bio->ex_data), idx));
  }
  
  unsigned long BIO_number_read(BIO *bio)
  {
      if (bio)
          return bio->num_read;
      return 0;
  }
  
  unsigned long BIO_number_written(BIO *bio)
  {
      if (bio)
          return bio->num_write;
      return 0;
  }
  
  IMPLEMENT_STACK_OF(BIO)
  