text: /*
   * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (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
   */
  
  #define OPENSSL_SUPPRESS_DEPRECATED
  
  #include <stdio.h>
  #include <errno.h>
  #include <openssl/crypto.h>
  #include "bio_local.h"
  
  /*
   * Helper macro for the callback to determine whether an operator expects a
   * len parameter or not
   */
  #define HAS_LEN_OPER(o) ((o) == BIO_CB_READ || (o) == BIO_CB_WRITE \
                           || (o) == BIO_CB_GETS)
  
  #ifndef OPENSSL_NO_DEPRECATED_3_0
  # define HAS_CALLBACK(b) ((b)->callback != NULL || (b)->callback_ex != NULL)
  #else
  # define HAS_CALLBACK(b) ((b)->callback_ex != NULL)
  #endif
  /*
   * Helper function to work out whether to call the new style callback or the old
   * one, and translate between the two.
   *
   * This has a long return type for consistency with the old callback. Similarly
   * for the "long" used for "inret"
   */
  static long bio_call_callback(BIO *b, int oper, const char *argp, size_t len,
                                int argi, long argl, long inret,
                                size_t *processed)
  {
      long ret = inret;
  #ifndef OPENSSL_NO_DEPRECATED_3_0
      int bareoper;
  
      if (b->callback_ex != NULL)
  #endif
          return b->callback_ex(b, oper, argp, len, argi, argl, inret, processed);
  
  #ifndef OPENSSL_NO_DEPRECATED_3_0
      /* Strip off any BIO_CB_RETURN flag */
      bareoper = oper & ~BIO_CB_RETURN;
  
      /*
       * We have an old style callback, so we will have to do nasty casts and
       * check for overflows.
       */
      if (HAS_LEN_OPER(bareoper)) {
          /* In this case |len| is set, and should be used instead of |argi| */
          if (len > INT_MAX)
              return -1;
  
          argi = (int)len;
      }
  
      if (inret > 0 && (oper & BIO_CB_RETURN) && bareoper != BIO_CB_CTRL) {
          if (*processed > INT_MAX)
              return -1;
          inret = *processed;
      }
  
      ret = b->callback(b, oper, argp, argi, argl, inret);
  
      if (ret > 0 && (oper & BIO_CB_RETURN) && bareoper != BIO_CB_CTRL) {
          *processed = (size_t)ret;
          ret = 1;
      }
  #endif
      return ret;
  }
  
  BIO *BIO_new_ex(OSSL_LIB_CTX *libctx, const BIO_METHOD *method)
  {
      BIO *bio = OPENSSL_zalloc(sizeof(*bio));
  
      if (bio == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
          return NULL;
      }
  
      bio->libctx = libctx;
      bio->method = method;
      bio->shutdown = 1;
      bio->references = 1;
  
      if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data))
          goto err;
  
      bio->lock = CRYPTO_THREAD_lock_new();
      if (bio->lock == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
          CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data);
          goto err;
      }
  
      if (method->create != NULL && !method->create(bio)) {
          ERR_raise(ERR_LIB_BIO, ERR_R_INIT_FAIL);
          CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data);
          CRYPTO_THREAD_lock_free(bio->lock);
          goto err;
      }
      if (method->create == NULL)
          bio->init = 1;
  
      return bio;
  
  err:
      OPENSSL_free(bio);
      return NULL;
  }
  
  BIO *BIO_new(const BIO_METHOD *method)
  {
      return BIO_new_ex(NULL, method);
  }
  
  int BIO_free(BIO *a)
  {
      int ret;
  
      if (a == NULL)
          return 0;
  
      if (CRYPTO_DOWN_REF(&a->references, &ret, a->lock) <= 0)
          return 0;
  
      REF_PRINT_COUNT("BIO", a);
      if (ret > 0)
          return 1;
      REF_ASSERT_ISNT(ret < 0);
  
      if (HAS_CALLBACK(a)) {
          ret = (int)bio_call_callback(a, BIO_CB_FREE, NULL, 0, 0, 0L, 1L, NULL);
          if (ret <= 0)
              return ret;
      }
  
      if ((a->method != NULL) && (a->method->destroy != NULL))
          a->method->destroy(a);
  
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, a, &a->ex_data);
  
      CRYPTO_THREAD_lock_free(a->lock);
  
      OPENSSL_free(a);
  
      return 1;
  }
  
  void BIO_set_data(BIO *a, void *ptr)
  {
      a->ptr = ptr;
  }
  
  void *BIO_get_data(BIO *a)
  {
      return a->ptr;
  }
  
  void BIO_set_init(BIO *a, int init)
  {
      a->init = init;
  }
  
  int BIO_get_init(BIO *a)
  {
      return a->init;
  }
  
  void BIO_set_shutdown(BIO *a, int shut)
  {
      a->shutdown = shut;
  }
  
  int BIO_get_shutdown(BIO *a)
  {
      return a->shutdown;
  }
  
  void BIO_vfree(BIO *a)
  {
      BIO_free(a);
  }
  
  int BIO_up_ref(BIO *a)
  {
      int i;
  
      if (CRYPTO_UP_REF(&a->references, &i, a->lock) <= 0)
          return 0;
  
      REF_PRINT_COUNT("BIO", a);
      REF_ASSERT_ISNT(i < 2);
      return i > 1;
  }
  
  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;
  }
  
  #ifndef OPENSSL_NO_DEPRECATED_3_0
  BIO_callback_fn BIO_get_callback(const BIO *b)
  {
      return b->callback;
  }
  
  void BIO_set_callback(BIO *b, BIO_callback_fn cb)
  {
      b->callback = cb;
  }
  #endif
  
  BIO_callback_fn_ex BIO_get_callback_ex(const BIO *b)
  {
      return b->callback_ex;
  }
  
  void BIO_set_callback_ex(BIO *b, BIO_callback_fn_ex cb)
  {
      b->callback_ex = 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;
  }
  
  /*
   * This is essentially the same as BIO_read_ex() except that it allows
   * 0 or a negative value to indicate failure (retryable or not) in the return.
   * This is for compatibility with the old style BIO_read(), where existing code
   * may make assumptions about the return value that it might get.
   */
  static int bio_read_intern(BIO *b, void *data, size_t dlen, size_t *readbytes)
  {
      int ret;
  
      if (b == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (b->method == NULL || b->method->bread == NULL) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (HAS_CALLBACK(b) &&
          ((ret = (int)bio_call_callback(b, BIO_CB_READ, data, dlen, 0, 0L, 1L,
                                         NULL)) <= 0))
          return ret;
  
      if (!b->init) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED);
          return -1;
      }
  
      ret = b->method->bread(b, data, dlen, readbytes);
  
      if (ret > 0)
          b->num_read += (uint64_t)*readbytes;
  
      if (HAS_CALLBACK(b))
          ret = (int)bio_call_callback(b, BIO_CB_READ | BIO_CB_RETURN, data,
                                       dlen, 0, 0L, ret, readbytes);
  
      /* Shouldn't happen */
      if (ret > 0 && *readbytes > dlen) {
          ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
          return -1;
      }
  
      return ret;
  }
  
  int BIO_read(BIO *b, void *data, int dlen)
  {
      size_t readbytes;
      int ret;
  
      if (dlen < 0)
          return 0;
  
      ret = bio_read_intern(b, data, (size_t)dlen, &readbytes);
  
      if (ret > 0) {
          /* *readbytes should always be <= dlen */
          ret = (int)readbytes;
      }
  
      return ret;
  }
  
  int BIO_read_ex(BIO *b, void *data, size_t dlen, size_t *readbytes)
  {
      return bio_read_intern(b, data, dlen, readbytes) > 0;
  }
  
  static int bio_write_intern(BIO *b, const void *data, size_t dlen,
                              size_t *written)
  {
      size_t local_written;
      int ret;
  
      if (written != NULL)
          *written = 0;
      /*
       * b == NULL is not an error but just means that zero bytes are written.
       * Do not raise an error here.
       */
      if (b == NULL)
          return 0;
  
      if (b->method == NULL || b->method->bwrite == NULL) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (HAS_CALLBACK(b) &&
          ((ret = (int)bio_call_callback(b, BIO_CB_WRITE, data, dlen, 0, 0L, 1L,
                                         NULL)) <= 0))
          return ret;
  
      if (!b->init) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED);
          return -1;
      }
  
      ret = b->method->bwrite(b, data, dlen, &local_written);
  
      if (ret > 0)
          b->num_write += (uint64_t)local_written;
  
      if (HAS_CALLBACK(b))
          ret = (int)bio_call_callback(b, BIO_CB_WRITE | BIO_CB_RETURN, data,
                                       dlen, 0, 0L, ret, &local_written);
  
      if (written != NULL)
          *written = local_written;
      return ret;
  }
  
  int BIO_write(BIO *b, const void *data, int dlen)
  {
      size_t written;
      int ret;
  
      if (dlen <= 0)
          return 0;
  
      ret = bio_write_intern(b, data, (size_t)dlen, &written);
  
      if (ret > 0) {
          /* written should always be <= dlen */
          ret = (int)written;
      }
  
      return ret;
  }
  
  int BIO_write_ex(BIO *b, const void *data, size_t dlen, size_t *written)
  {
      return bio_write_intern(b, data, dlen, written) >= 0;
  }
  
  int BIO_puts(BIO *b, const char *buf)
  {
      int ret;
      size_t written = 0;
  
      if (b == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (b->method == NULL || b->method->bputs == NULL) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (HAS_CALLBACK(b)) {
          ret = (int)bio_call_callback(b, BIO_CB_PUTS, buf, 0, 0, 0L, 1L, NULL);
          if (ret <= 0)
              return ret;
      }
  
      if (!b->init) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED);
          return -1;
      }
  
      ret = b->method->bputs(b, buf);
  
      if (ret > 0) {
          b->num_write += (uint64_t)ret;
          written = ret;
          ret = 1;
      }
  
      if (HAS_CALLBACK(b))
          ret = (int)bio_call_callback(b, BIO_CB_PUTS | BIO_CB_RETURN, buf, 0, 0,
                                       0L, ret, &written);
  
      if (ret > 0) {
          if (written > INT_MAX) {
              ERR_raise(ERR_LIB_BIO, BIO_R_LENGTH_TOO_LONG);
              ret = -1;
          } else {
              ret = (int)written;
          }
      }
  
      return ret;
  }
  
  int BIO_gets(BIO *b, char *buf, int size)
  {
      int ret;
      size_t readbytes = 0;
  
      if (b == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (b->method == NULL || b->method->bgets == NULL) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (size < 0) {
          ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT);
          return -1;
      }
  
      if (HAS_CALLBACK(b)) {
          ret = (int)bio_call_callback(b, BIO_CB_GETS, buf, size, 0, 0L, 1, NULL);
          if (ret <= 0)
              return ret;
      }
  
      if (!b->init) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED);
          return -1;
      }
  
      ret = b->method->bgets(b, buf, size);
  
      if (ret > 0) {
          readbytes = ret;
          ret = 1;
      }
  
      if (HAS_CALLBACK(b))
          ret = (int)bio_call_callback(b, BIO_CB_GETS | BIO_CB_RETURN, buf, size,
                                       0, 0L, ret, &readbytes);
  
      if (ret > 0) {
          /* Shouldn't happen */
          if (readbytes > (size_t)size)
              ret = -1;
          else
              ret = (int)readbytes;
      }
  
      return ret;
  }
  
  int BIO_get_line(BIO *bio, char *buf, int size)
  {
      int ret = 0;
      char *ptr = buf;
  
      if (buf == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (size <= 0) {
          ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT);
          return -1;
      }
      *buf = '\0';
  
      if (bio == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (!bio->init) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED);
          return -1;
      }
  
      while (size-- > 1 && (ret = BIO_read(bio, ptr, 1)) > 0)
          if (*ptr++ == '\n')
              break;
      *ptr = '\0';
      return ret > 0 || BIO_eof(bio) ? ptr - buf : ret;
  }
  
  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);
  }
  
  void *BIO_ptr_ctrl(BIO *b, int cmd, long larg)
  {
      void *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;
  
      if (b == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
      if (b->method == NULL || b->method->ctrl == NULL) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (HAS_CALLBACK(b)) {
          ret = bio_call_callback(b, BIO_CB_CTRL, parg, 0, cmd, larg, 1L, NULL);
          if (ret <= 0)
              return ret;
      }
  
      ret = b->method->ctrl(b, cmd, larg, parg);
  
      if (HAS_CALLBACK(b))
          ret = bio_call_callback(b, BIO_CB_CTRL | BIO_CB_RETURN, parg, 0, cmd,
                                  larg, ret, NULL);
  
      return ret;
  }
  
  long BIO_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
  {
      long ret;
  
      if (b == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -2;
      }
      if (b->method == NULL || b->method->callback_ctrl == NULL
              || cmd != BIO_CTRL_SET_CALLBACK) {
          ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_METHOD);
          return -2;
      }
  
      if (HAS_CALLBACK(b)) {
          ret = bio_call_callback(b, BIO_CB_CTRL, (void *)&fp, 0, cmd, 0, 1L,
                                  NULL);
          if (ret <= 0)
              return ret;
      }
  
      ret = b->method->callback_ctrl(b, cmd, fp);
  
      if (HAS_CALLBACK(b))
          ret = bio_call_callback(b, BIO_CB_CTRL | BIO_CB_RETURN, (void *)&fp, 0,
                                  cmd, 0, ret, NULL);
  
      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) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          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;
  }
  
  void BIO_set_retry_reason(BIO *bio, int reason)
  {
      bio->retry_reason = reason;
  }
  
  BIO *BIO_find_type(BIO *bio, int type)
  {
      int mt, mask;
  
      if (bio == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          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 == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return NULL;
      }
      return b->next_bio;
  }
  
  void BIO_set_next(BIO *b, BIO *next)
  {
      b->next_bio = next;
  }
  
  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;
  #ifndef OPENSSL_NO_DEPRECATED_3_0
          new_bio->callback = bio->callback;
  #endif
          new_bio->callback_ex = bio->callback_ex;
          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_set_ex_data(BIO *bio, int idx, void *data)
  {
      return CRYPTO_set_ex_data(&(bio->ex_data), idx, data);
  }
  
  void *BIO_get_ex_data(const BIO *bio, int idx)
  {
      return CRYPTO_get_ex_data(&(bio->ex_data), idx);
  }
  
  uint64_t BIO_number_read(BIO *bio)
  {
      if (bio)
          return bio->num_read;
      return 0;
  }
  
  uint64_t BIO_number_written(BIO *bio)
  {
      if (bio)
          return bio->num_write;
      return 0;
  }
  
  void bio_free_ex_data(BIO *bio)
  {
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_BIO, bio, &bio->ex_data);
  }
  
  void bio_cleanup(void)
  {
  #ifndef OPENSSL_NO_SOCK
      bio_sock_cleanup_int();
      CRYPTO_THREAD_lock_free(bio_lookup_lock);
      bio_lookup_lock = NULL;
  #endif
      CRYPTO_THREAD_lock_free(bio_type_lock);
      bio_type_lock = NULL;
  }
  
  /* Internal variant of the below BIO_wait() not calling BIOerr() */
  static int bio_wait(BIO *bio, time_t max_time, unsigned int nap_milliseconds)
  {
  #ifndef OPENSSL_NO_SOCK
      int fd;
  #endif
      long sec_diff;
  
      if (max_time == 0) /* no timeout */
          return 1;
  
  #ifndef OPENSSL_NO_SOCK
      if (BIO_get_fd(bio, &fd) > 0 && fd < FD_SETSIZE)
          return BIO_socket_wait(fd, BIO_should_read(bio), max_time);
  #endif
      /* fall back to polling since no sockets are available */
  
      sec_diff = (long)(max_time - time(NULL)); /* might overflow */
      if (sec_diff < 0)
          return 0; /* clearly timeout */
  
      /* now take a nap at most the given number of milliseconds */
      if (sec_diff == 0) { /* we are below the 1 seconds resolution of max_time */
          if (nap_milliseconds > 1000)
              nap_milliseconds = 1000;
      } else { /* for sec_diff > 0, take min(sec_diff * 1000, nap_milliseconds) */
          if ((unsigned long)sec_diff * 1000 < nap_milliseconds)
              nap_milliseconds = (unsigned int)sec_diff * 1000;
      }
      ossl_sleep(nap_milliseconds);
      return 1;
  }
  
  /*-
   * Wait on (typically socket-based) BIO at most until max_time.
   * Succeed immediately if max_time == 0.
   * If sockets are not available support polling: succeed after waiting at most
   * the number of nap_milliseconds in order to avoid a tight busy loop.
   * Call BIOerr(...) on timeout or error.
   * Returns -1 on error, 0 on timeout, and 1 on success.
   */
  int BIO_wait(BIO *bio, time_t max_time, unsigned int nap_milliseconds)
  {
      int rv = bio_wait(bio, max_time, nap_milliseconds);
  
      if (rv <= 0)
          ERR_raise(ERR_LIB_BIO,
                    rv == 0 ? BIO_R_TRANSFER_TIMEOUT : BIO_R_TRANSFER_ERROR);
      return rv;
  }
  
  /*
   * Connect via given BIO using BIO_do_connect() until success/timeout/error.
   * Parameter timeout == 0 means no timeout, < 0 means exactly one try.
   * For non-blocking and potentially even non-socket BIOs perform polling with
   * the given density: between polls sleep nap_milliseconds using BIO_wait()
   * in order to avoid a tight busy loop.
   * Returns -1 on error, 0 on timeout, and 1 on success.
   */
  int BIO_do_connect_retry(BIO *bio, int timeout, int nap_milliseconds)
  {
      int blocking = timeout <= 0;
      time_t max_time = timeout > 0 ? time(NULL) + timeout : 0;
      int rv;
  
      if (bio == NULL) {
          ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
  
      if (nap_milliseconds < 0)
          nap_milliseconds = 100;
      BIO_set_nbio(bio, !blocking);
  
   retry:
      ERR_set_mark();
      rv = BIO_do_connect(bio);
  
      if (rv <= 0) { /* could be timeout or retryable error or fatal error */
          int err = ERR_peek_last_error();
          int reason = ERR_GET_REASON(err);
          int do_retry = BIO_should_retry(bio); /* may be 1 only if !blocking */
  
          if (ERR_GET_LIB(err) == ERR_LIB_BIO) {
              switch (reason) {
              case ERR_R_SYS_LIB:
                  /*
                   * likely retryable system error occurred, which may be
                   * EAGAIN (resource temporarily unavailable) some 40 secs after
                   * calling getaddrinfo(): Temporary failure in name resolution
                   * or a premature ETIMEDOUT, some 30 seconds after connect()
                   */
              case BIO_R_CONNECT_ERROR:
              case BIO_R_NBIO_CONNECT_ERROR:
                  /* some likely retryable connection error occurred */
                  (void)BIO_reset(bio); /* often needed to avoid retry failure */
                  do_retry = 1;
                  break;
              default:
                  break;
              }
          }
          if (timeout >= 0 && do_retry) {
              ERR_pop_to_mark();
              /* will not actually wait if timeout == 0 (i.e., blocking BIO): */
              rv = bio_wait(bio, max_time, nap_milliseconds);
              if (rv > 0)
                  goto retry;
              ERR_raise(ERR_LIB_BIO,
                        rv == 0 ? BIO_R_CONNECT_TIMEOUT : BIO_R_CONNECT_ERROR);
          } else {
              ERR_clear_last_mark();
              rv = -1;
              if (err == 0) /* missing error queue entry */
                  /* workaround: general error */
                  ERR_raise(ERR_LIB_BIO, BIO_R_CONNECT_ERROR);
          }
      } else {
          ERR_clear_last_mark();
      }
  
      return rv;
  }
  