// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/bio.h>

#if !defined(OPENSSL_NO_POSIX_IO)

#include <errno.h>

#include <string.h>

#if !defined(OPENSSL_WINDOWS)

#include <unistd.h>

#else

#include <io.h>

#endif

#include <openssl/err.h>

#include <openssl/mem.h>

#include "internal.h"

#include "../internal.h"

#if defined(OPENSSL_WINDOWS)

  #define BORINGSSL_CLOSE _close

  #define BORINGSSL_LSEEK _lseek

  #define BORINGSSL_READ _read

  #define BORINGSSL_WRITE _write

#else

  #define BORINGSSL_CLOSE close

  #define BORINGSSL_LSEEK lseek

  #define BORINGSSL_READ read

  #define BORINGSSL_WRITE write

#endif

BIO *BIO_new_fd(int fd, int close_flag) {

  BIO *ret = BIO_new(BIO_s_fd());

  if (ret == NULL) {

    return NULL;

  }

  BIO_set_fd(ret, fd, close_flag);

  return ret;

}

static int fd_new(BIO *bio) {

  // num is used to store the file descriptor.

  bio->num = -1;

  return 1;

}

static int fd_free(BIO *bio) {

  if (bio->shutdown) {

    if (bio->init) {

      BORINGSSL_CLOSE(bio->num);

    }

    bio->init = 0;

  }

  return 1;

}

static int fd_read(BIO *b, char *out, int outl) {

  int ret = 0;

  ret = (int)BORINGSSL_READ(b->num, out, outl);

  BIO_clear_retry_flags(b);

  if (ret <= 0) {

    if (bio_errno_should_retry(ret)) {

      BIO_set_retry_read(b);

    }

  }

  return ret;

}

static int fd_write(BIO *b, const char *in, int inl) {

  int ret = (int)BORINGSSL_WRITE(b->num, in, inl);

  BIO_clear_retry_flags(b);

  if (ret <= 0) {

    if (bio_errno_should_retry(ret)) {

      BIO_set_retry_write(b);

    }

  }

  return ret;

}

static long fd_ctrl(BIO *b, int cmd, long num, void *ptr) {

  switch (cmd) {

    case BIO_CTRL_RESET:

      num = 0;

      [[fallthrough]];

    case BIO_C_FILE_SEEK:

      if (b->init) {

        return (long)BORINGSSL_LSEEK(b->num, num, SEEK_SET);

      }

      return 0;

    case BIO_C_FILE_TELL:

    case BIO_CTRL_INFO:

      if (b->init) {

        return (long)BORINGSSL_LSEEK(b->num, 0, SEEK_CUR);

      }

      return 0;

    case BIO_C_SET_FD:

      fd_free(b);

      b->num = *static_cast<int *>(ptr);

      b->shutdown = static_cast<int>(num);

      b->init = 1;

      return 1;

    case BIO_C_GET_FD:

      if (b->init) {

        int *out = static_cast<int *>(ptr);

        if (out != nullptr) {

          *out = b->num;

        }

        return b->num;

      } else {

        return -1;

      }

    case BIO_CTRL_GET_CLOSE:

      return b->shutdown;

    case BIO_CTRL_SET_CLOSE:

      b->shutdown = static_cast<int>(num);

      return 1;

    case BIO_CTRL_FLUSH:

      return 1;

    default:

      return 0;

  }

}

static int fd_gets(BIO *bp, char *buf, int size) {

  if (size <= 0) {

    return 0;

  }

  char *ptr = buf;

  char *end = buf + size - 1;

  while (ptr < end && fd_read(bp, ptr, 1) > 0) {

    char c = ptr[0];

    ptr++;

    if (c == '\n') {

      break;

    }

  }

  ptr[0] = '\0';

  // The output length is bounded by |size|.

  return (int)(ptr - buf);

}

static const BIO_METHOD methods_fdp = {

    BIO_TYPE_FD, "file descriptor", fd_write,

    fd_read,     fd_gets,           fd_ctrl,

    fd_new,      fd_free,           /*callback_ctrl=*/nullptr,

};

const BIO_METHOD *BIO_s_fd(void) { return &methods_fdp; }

#endif  // OPENSSL_NO_POSIX_IO

int BIO_set_fd(BIO *bio, int fd, int close_flag) {

  return (int)BIO_int_ctrl(bio, BIO_C_SET_FD, close_flag, fd);

}

int BIO_get_fd(BIO *bio, int *out_fd) {

  return (int)BIO_ctrl(bio, BIO_C_GET_FD, 0, (char *) out_fd);

}