sdk/lib/fdio/fd.cc

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <lib/fdio/fd.h>
#include <lib/fdio/fdio.h>
#include <lib/fdio/unsafe.h>
#include <zircon/assert.h>

#include <fbl/auto_lock.h>

#include "internal.h"

__EXPORT
zx_status_t fdio_fd_create(zx_handle_t handle, int* fd_out) {
  fdio_t* io = nullptr;
  zx_status_t status = fdio_create(handle, &io);
  if (status != ZX_OK) {
    return status;
  }
  int fd = fdio_bind_to_fd(io, -1, 0);
  if (fd < 0) {
    io->release();
    return ZX_ERR_BAD_STATE;
  }
  *fd_out = fd;
  return ZX_OK;
}

__EXPORT
zx_status_t fdio_cwd_clone(zx_handle_t* out_handle) {
  fdio_t* cwd = []() {
    fbl::AutoLock lock(&fdio_lock);
    return fdio_cwd_handle;
  }();
  return cwd->clone(out_handle);
}

__EXPORT
zx_status_t fdio_fd_clone(int fd, zx_handle_t* out_handle) {
  fdio_t* io;
  if ((io = fdio_unsafe_fd_to_io(fd)) == nullptr) {
    return ZX_ERR_INVALID_ARGS;
  }
  // TODO(fxbug.dev/30920): implement/honor close-on-exec flag
  zx_status_t status = io->clone(out_handle);
  io->release();
  return status;
}

__EXPORT
zx_status_t fdio_fd_transfer(int fd, zx_handle_t* out_handle) {
  fdio_t* io;
  zx_status_t status = fdio_unbind_from_fd(fd, &io);
  if (status != ZX_OK) {
    return status;
  }
  // Unwrapping here is safe, because |fdio_unbind_from_fd| will only succeed
  // if we have the last unique reference to |io|.
  status = io->unwrap(out_handle);
  io->release();
  return status;
}