dolphin/Source/Core/Common/CDUtils.cpp

// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

// Most of the code in this file was shamelessly ripped from libcdio With minor adjustments

#include <algorithm>
#include <cstdlib>
#include <string>
#include <vector>

#include <fmt/format.h>

#include "Common/CDUtils.h"
#include "Common/Common.h"
#include "Common/CommonTypes.h"
#include "Common/StringUtil.h"

#ifdef _WIN32
#include <windows.h>
#elif __APPLE__
#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOBSD.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/storage/IOCDMedia.h>
#include <IOKit/storage/IOMedia.h>
#include <paths.h>
#else
#include <climits>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#endif  // WIN32

#ifdef __linux__
#include <linux/cdrom.h>
#endif

namespace Common
{
#ifdef _WIN32
// takes a root drive path, returns true if it is a cdrom drive
static bool IsCDROM(const TCHAR* drive)
{
  return (DRIVE_CDROM == GetDriveType(drive));
}

// Returns a vector with the device names
std::vector<std::string> GetCDDevices()
{
  std::vector<std::string> drives;

  const DWORD buffsize = GetLogicalDriveStrings(0, nullptr);
  std::vector<TCHAR> buff(buffsize);
  if (GetLogicalDriveStrings(buffsize, buff.data()) == buffsize - 1)
  {
    auto drive = buff.data();
    while (*drive)
    {
      if (IsCDROM(drive))
      {
        std::string str(TStrToUTF8(drive));
        str.pop_back();  // we don't want the final backslash
        drives.push_back(std::move(str));
      }

      // advance to next drive
      while (*drive++)
      {
      }
    }
  }
  return drives;
}
#elif defined __APPLE__
// Returns a pointer to an array of strings with the device names
std::vector<std::string> GetCDDevices()
{
  io_object_t next_media;
  mach_port_t master_port;
  kern_return_t kern_result;
  io_iterator_t media_iterator;
  CFMutableDictionaryRef classes_to_match;
  std::vector<std::string> drives;

  kern_result = IOMasterPort(MACH_PORT_NULL, &master_port);
  if (kern_result != KERN_SUCCESS)
    return drives;

  classes_to_match = IOServiceMatching(kIOCDMediaClass);
  if (classes_to_match == nullptr)
    return drives;

  CFDictionarySetValue(classes_to_match, CFSTR(kIOMediaEjectableKey), kCFBooleanTrue);

  kern_result = IOServiceGetMatchingServices(master_port, classes_to_match, &media_iterator);
  if (kern_result != KERN_SUCCESS)
    return drives;

  next_media = IOIteratorNext(media_iterator);
  if (next_media != 0)
  {
    CFTypeRef str_bsd_path;

    do
    {
      str_bsd_path =
          IORegistryEntryCreateCFProperty(next_media, CFSTR(kIOBSDNameKey), kCFAllocatorDefault, 0);
      if (str_bsd_path == nullptr)
      {
        IOObjectRelease(next_media);
        continue;
      }

      if (CFGetTypeID(str_bsd_path) == CFStringGetTypeID())
      {
        size_t buf_size = CFStringGetLength((CFStringRef)str_bsd_path) * 4 + 1;
        char* buf = new char[buf_size];

        if (CFStringGetCString((CFStringRef)str_bsd_path, buf, buf_size, kCFStringEncodingUTF8))
        {
          // Below, by appending 'r' to the BSD node name, we indicate
          // a raw disk. Raw disks receive I/O requests directly and
          // don't go through a buffer cache.
          drives.push_back(std::string(_PATH_DEV "r") + buf);
        }

        delete[] buf;
      }
      CFRelease(str_bsd_path);
      IOObjectRelease(next_media);
    } while ((next_media = IOIteratorNext(media_iterator)) != 0);
  }
  IOObjectRelease(media_iterator);
  return drives;
}
#else
// checklist: /dev/cdrom, /dev/dvd /dev/hd?, /dev/scd? /dev/sr?
struct CheckListEntry
{
  const char* format;
  unsigned int num_min;
  unsigned int num_max;
};

constexpr CheckListEntry checklist[] = {
#ifdef __linux__
    {"/dev/cdrom", 0, 0},  {"/dev/dvd", 0, 0},   {"/dev/hd{}", 'a', 'z'},
    {"/dev/scd{}", 0, 27}, {"/dev/sr{}", 0, 27},
#else
    {"/dev/acd{}", 0, 27},
    {"/dev/cd{}", 0, 27},
#endif
    {nullptr, 0, 0},
};

// Returns true if a device is a block or char device and not a symbolic link
static bool IsDevice(const std::string& source_name)
{
  struct stat buf;
  if (0 != lstat(source_name.c_str(), &buf))
    return false;

  return ((S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode)) && !S_ISLNK(buf.st_mode));
}

// Check a device to see if it is a DVD/CD-ROM drive
static bool IsCDROM(const std::string& drive)
{
  // Check if the device exists
  if (!IsDevice(drive))
    return false;

  bool is_cd = false;
  // If it does exist, verify that it is a cdrom/dvd drive
  int cdfd = open(drive.c_str(), (O_RDONLY | O_NONBLOCK), 0);
  if (cdfd >= 0)
  {
#ifdef __linux__
    if (ioctl(cdfd, CDROM_GET_CAPABILITY, 0) != -1)
#endif
      is_cd = true;
    close(cdfd);
  }
  return is_cd;
}

// Returns a pointer to an array of strings with the device names
std::vector<std::string> GetCDDevices()
{
  std::vector<std::string> drives;
  // Scan the system for DVD/CD-ROM drives.
  for (unsigned int i = 0; checklist[i].format; ++i)
  {
    for (unsigned int j = checklist[i].num_min; j <= checklist[i].num_max; ++j)
    {
      std::string drive = fmt::format(checklist[i].format, j);
      if (IsCDROM(drive))
      {
        drives.push_back(std::move(drive));
      }
    }
  }
  return drives;
}
#endif

// Returns true if device is a cdrom/dvd drive
bool IsCDROMDevice(std::string device)
{
#ifndef _WIN32
  // Resolve symbolic links. This allows symbolic links to valid
  // drives to be passed from the command line with the -e flag.
  char resolved_path[PATH_MAX];
  char* devname = realpath(device.c_str(), resolved_path);
  if (!devname)
    return false;
  device = devname;
#endif

  std::vector<std::string> devices = GetCDDevices();
  for (const std::string& d : devices)
  {
    if (d == device)
      return true;
  }
  return false;
}
}  // namespace Common