text: /*
   * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include <stdio.h>
  #include <errno.h>
  #include "bio_lcl.h"
  #include "internal/cryptlib.h"
  
  static int null_write(BIO *h, const char *buf, int num);
  static int null_read(BIO *h, char *buf, int size);
  static int null_puts(BIO *h, const char *str);
  static int null_gets(BIO *h, char *str, int size);
  static long null_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  static int null_new(BIO *h);
  static int null_free(BIO *data);
  static const BIO_METHOD null_method = {
      BIO_TYPE_NULL,
      "NULL",
      /* TODO: Convert to new style write function */
      bwrite_conv,
      null_write,
      /* TODO: Convert to new style read function */
      bread_conv,
      null_read,
      null_puts,
      null_gets,
      null_ctrl,
      null_new,
      null_free,
      NULL,
  };
  
  const BIO_METHOD *BIO_s_null(void)
  {
      return (&null_method);
  }
  
  static int null_new(BIO *bi)
  {
      bi->init = 1;
      bi->num = 0;
      bi->ptr = (NULL);
      return (1);
  }
  
  static int null_free(BIO *a)
  {
      if (a == NULL)
          return (0);
      return (1);
  }
  
  static int null_read(BIO *b, char *out, int outl)
  {
      return (0);
  }
  
  static int null_write(BIO *b, const char *in, int inl)
  {
      return (inl);
  }
  
  static long null_ctrl(BIO *b, int cmd, long num, void *ptr)
  {
      long ret = 1;
  
      switch (cmd) {
      case BIO_CTRL_RESET:
      case BIO_CTRL_EOF:
      case BIO_CTRL_SET:
      case BIO_CTRL_SET_CLOSE:
      case BIO_CTRL_FLUSH:
      case BIO_CTRL_DUP:
          ret = 1;
          break;
      case BIO_CTRL_GET_CLOSE:
      case BIO_CTRL_INFO:
      case BIO_CTRL_GET:
      case BIO_CTRL_PENDING:
      case BIO_CTRL_WPENDING:
      default:
          ret = 0;
          break;
      }
      return (ret);
  }
  
  static int null_gets(BIO *bp, char *buf, int size)
  {
      return (0);
  }
  
  static int null_puts(BIO *bp, const char *str)
  {
      if (str == NULL)
          return (0);
      return (strlen(str));
  }
  