SDL/src/hidapi/SDL_hidapi.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/* Original hybrid wrapper for Linux by Valve Software. Their original notes:
 *
 * The libusb version doesn't support Bluetooth, but not all Linux
 * distributions allow access to /dev/hidraw*
 *
 * This merges the two, at a small performance cost, until distributions
 * have granted access to /dev/hidraw*
 */

#include "SDL_internal.h"

#include "SDL_hidapi_c.h"
#include "../joystick/usb_ids.h"
#include "../SDL_hints_c.h"

// Initial type declarations
#define HID_API_NO_EXPORT_DEFINE // do not export hidapi procedures
#include "hidapi/hidapi.h"

#ifndef SDL_HIDAPI_DISABLED

#ifdef SDL_LIBUSB_DYNAMIC
SDL_ELF_NOTE_DLOPEN(
    "hidabi-libusb",
    "Support for joysticks through libusb",
    SDL_ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
    SDL_LIBUSB_DYNAMIC
);
#endif

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
#include "../core/windows/SDL_windows.h"
#endif

#ifdef SDL_PLATFORM_MACOS
#include <CoreFoundation/CoreFoundation.h>
#include <mach/mach.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/hid/IOHIDDevice.h>
#include <IOKit/usb/USBSpec.h>
#include <AvailabilityMacros.h>
// Things named "Master" were renamed to "Main" in macOS 12.0's SDK.
#if MAC_OS_X_VERSION_MIN_REQUIRED < 120000
#define kIOMainPortDefault kIOMasterPortDefault
#endif
#endif

#include "../core/linux/SDL_udev.h"
#ifdef SDL_USE_LIBUDEV
#include <poll.h>
#endif

#ifdef HAVE_INOTIFY
#include <string.h> // strerror
#include <errno.h>  // errno
#include <fcntl.h>
#include <limits.h> // For the definition of NAME_MAX
#include <sys/inotify.h>
#endif

#if defined(SDL_USE_LIBUDEV) || defined(HAVE_INOTIFY)
#include <unistd.h>
#endif

#ifdef SDL_USE_LIBUDEV
typedef enum
{
    ENUMERATION_UNSET,
    ENUMERATION_LIBUDEV,
    ENUMERATION_FALLBACK
} LinuxEnumerationMethod;

static LinuxEnumerationMethod linux_enumeration_method = ENUMERATION_UNSET;
#endif

#ifdef HAVE_INOTIFY
static int inotify_fd = -1;
#endif

#ifdef SDL_USE_LIBUDEV
static const SDL_UDEV_Symbols *usyms = NULL;
#endif

static struct
{
    bool m_bInitialized;
    Uint32 m_unDeviceChangeCounter;
    bool m_bCanGetNotifications;
    Uint64 m_unLastDetect;

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
    SDL_ThreadID m_nThreadID;
    WNDCLASSEXA m_wndClass;
    HWND m_hwndMsg;
    HDEVNOTIFY m_hNotify;
    double m_flLastWin32MessageCheck;
#endif

#ifdef SDL_PLATFORM_MACOS
    IONotificationPortRef m_notificationPort;
    mach_port_t m_notificationMach;
#endif

#ifdef SDL_USE_LIBUDEV
    struct udev *m_pUdev;
    struct udev_monitor *m_pUdevMonitor;
    int m_nUdevFd;
#endif
} SDL_HIDAPI_discovery;

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
struct _DEV_BROADCAST_HDR
{
    DWORD dbch_size;
    DWORD dbch_devicetype;
    DWORD dbch_reserved;
};

typedef struct _DEV_BROADCAST_DEVICEINTERFACE_A
{
    DWORD dbcc_size;
    DWORD dbcc_devicetype;
    DWORD dbcc_reserved;
    GUID dbcc_classguid;
    char dbcc_name[1];
} DEV_BROADCAST_DEVICEINTERFACE_A, *PDEV_BROADCAST_DEVICEINTERFACE_A;

typedef struct _DEV_BROADCAST_HDR DEV_BROADCAST_HDR;
#define DBT_DEVICEARRIVAL          0x8000     // system detected a new device
#define DBT_DEVICEREMOVECOMPLETE   0x8004     // device was removed from the system
#define DBT_DEVTYP_DEVICEINTERFACE 0x00000005 // device interface class
#define DBT_DEVNODES_CHANGED       0x0007
#define DBT_CONFIGCHANGED          0x0018
#define DBT_DEVICETYPESPECIFIC     0x8005 // type specific event
#define DBT_DEVINSTSTARTED         0x8008 // device installed and started

#include <initguid.h>
DEFINE_GUID(GUID_DEVINTERFACE_USB_DEVICE, 0xA5DCBF10L, 0x6530, 0x11D2, 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED);

static LRESULT CALLBACK ControllerWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message) {
    case WM_DEVICECHANGE:
        switch (wParam) {
        case DBT_DEVICEARRIVAL:
        case DBT_DEVICEREMOVECOMPLETE:
            if (((DEV_BROADCAST_HDR *)lParam)->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
                ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
            }
            break;
        }
        return TRUE;
    }

    return DefWindowProc(hwnd, message, wParam, lParam);
}
#endif // defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)

#ifdef SDL_PLATFORM_MACOS
static void CallbackIOServiceFunc(void *context, io_iterator_t portIterator)
{
    // Must drain the iterator, or we won't receive new notifications
    io_object_t entry;
    while ((entry = IOIteratorNext(portIterator)) != 0) {
        IOObjectRelease(entry);
        ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
    }
}
#endif // SDL_PLATFORM_MACOS

#ifdef HAVE_INOTIFY
#ifdef HAVE_INOTIFY_INIT1
static int SDL_inotify_init1(void)
{
    return inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
}
#else
static int SDL_inotify_init1(void)
{
    int fd = inotify_init();
    if (fd < 0) {
        return -1;
    }
    fcntl(fd, F_SETFL, O_NONBLOCK);
    fcntl(fd, F_SETFD, FD_CLOEXEC);
    return fd;
}
#endif

static int StrHasPrefix(const char *string, const char *prefix)
{
    return SDL_strncmp(string, prefix, SDL_strlen(prefix)) == 0;
}

static int StrIsInteger(const char *string)
{
    const char *p;

    if (*string == '\0') {
        return 0;
    }

    for (p = string; *p != '\0'; p++) {
        if (*p < '0' || *p > '9') {
            return 0;
        }
    }

    return 1;
}
#endif // HAVE_INOTIFY

static void HIDAPI_InitializeDiscovery(void)
{
    SDL_HIDAPI_discovery.m_bInitialized = true;
    SDL_HIDAPI_discovery.m_unDeviceChangeCounter = 1;
    SDL_HIDAPI_discovery.m_bCanGetNotifications = false;
    SDL_HIDAPI_discovery.m_unLastDetect = 0;

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
    SDL_HIDAPI_discovery.m_nThreadID = SDL_GetCurrentThreadID();

    SDL_zero(SDL_HIDAPI_discovery.m_wndClass);
    SDL_HIDAPI_discovery.m_wndClass.hInstance = GetModuleHandle(NULL);
    SDL_HIDAPI_discovery.m_wndClass.lpszClassName = "SDL_HIDAPI_DEVICE_DETECTION";
    SDL_HIDAPI_discovery.m_wndClass.lpfnWndProc = ControllerWndProc; // This function is called by windows
    SDL_HIDAPI_discovery.m_wndClass.cbSize = sizeof(WNDCLASSEX);

    RegisterClassExA(&SDL_HIDAPI_discovery.m_wndClass);
    SDL_HIDAPI_discovery.m_hwndMsg = CreateWindowExA(0, "SDL_HIDAPI_DEVICE_DETECTION", NULL, 0, 0, 0, 0, 0, HWND_MESSAGE, NULL, NULL, NULL);

    {
        DEV_BROADCAST_DEVICEINTERFACE_A devBroadcast;

        SDL_zero(devBroadcast);
        devBroadcast.dbcc_size = sizeof(devBroadcast);
        devBroadcast.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
        devBroadcast.dbcc_classguid = GUID_DEVINTERFACE_USB_DEVICE;

        /* DEVICE_NOTIFY_ALL_INTERFACE_CLASSES is important, makes GUID_DEVINTERFACE_USB_DEVICE ignored,
         * but that seems to be necessary to get a notice after each individual usb input device actually
         * installs, rather than just as the composite device is seen.
         */
        SDL_HIDAPI_discovery.m_hNotify = RegisterDeviceNotification(SDL_HIDAPI_discovery.m_hwndMsg, &devBroadcast, DEVICE_NOTIFY_WINDOW_HANDLE | DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);
        SDL_HIDAPI_discovery.m_bCanGetNotifications = (SDL_HIDAPI_discovery.m_hNotify != 0);
    }
#endif // defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)

#ifdef SDL_PLATFORM_MACOS
    SDL_HIDAPI_discovery.m_notificationPort = IONotificationPortCreate(kIOMainPortDefault);
    if (SDL_HIDAPI_discovery.m_notificationPort) {
        {
            io_iterator_t portIterator = 0;
            io_object_t entry;
            IOReturn result = IOServiceAddMatchingNotification(
                SDL_HIDAPI_discovery.m_notificationPort,
                kIOFirstMatchNotification,
                IOServiceMatching(kIOHIDDeviceKey),
                CallbackIOServiceFunc, NULL, &portIterator);

            if (result == 0) {
                // Must drain the existing iterator, or we won't receive new notifications
                while ((entry = IOIteratorNext(portIterator)) != 0) {
                    IOObjectRelease(entry);
                }
            } else {
                IONotificationPortDestroy(SDL_HIDAPI_discovery.m_notificationPort);
                SDL_HIDAPI_discovery.m_notificationPort = nil;
            }
        }
        {
            io_iterator_t portIterator = 0;
            io_object_t entry;
            IOReturn result = IOServiceAddMatchingNotification(
                SDL_HIDAPI_discovery.m_notificationPort,
                kIOTerminatedNotification,
                IOServiceMatching(kIOHIDDeviceKey),
                CallbackIOServiceFunc, NULL, &portIterator);

            if (result == 0) {
                // Must drain the existing iterator, or we won't receive new notifications
                while ((entry = IOIteratorNext(portIterator)) != 0) {
                    IOObjectRelease(entry);
                }
            } else {
                IONotificationPortDestroy(SDL_HIDAPI_discovery.m_notificationPort);
                SDL_HIDAPI_discovery.m_notificationPort = nil;
            }
        }
    }

    SDL_HIDAPI_discovery.m_notificationMach = MACH_PORT_NULL;
    if (SDL_HIDAPI_discovery.m_notificationPort) {
        SDL_HIDAPI_discovery.m_notificationMach = IONotificationPortGetMachPort(SDL_HIDAPI_discovery.m_notificationPort);
    }

    SDL_HIDAPI_discovery.m_bCanGetNotifications = (SDL_HIDAPI_discovery.m_notificationMach != MACH_PORT_NULL);

#endif // SDL_PLATFORM_MACOS

#ifdef SDL_USE_LIBUDEV
    if (linux_enumeration_method == ENUMERATION_LIBUDEV) {
        SDL_HIDAPI_discovery.m_pUdev = NULL;
        SDL_HIDAPI_discovery.m_pUdevMonitor = NULL;
        SDL_HIDAPI_discovery.m_nUdevFd = -1;

        usyms = SDL_UDEV_GetUdevSyms();
        if (usyms != NULL) {
            SDL_HIDAPI_discovery.m_pUdev = usyms->udev_new();
            if (SDL_HIDAPI_discovery.m_pUdev != NULL) {
                SDL_HIDAPI_discovery.m_pUdevMonitor = usyms->udev_monitor_new_from_netlink(SDL_HIDAPI_discovery.m_pUdev, "udev");
                if (SDL_HIDAPI_discovery.m_pUdevMonitor != NULL) {
                    usyms->udev_monitor_enable_receiving(SDL_HIDAPI_discovery.m_pUdevMonitor);
                    SDL_HIDAPI_discovery.m_nUdevFd = usyms->udev_monitor_get_fd(SDL_HIDAPI_discovery.m_pUdevMonitor);
                    SDL_HIDAPI_discovery.m_bCanGetNotifications = true;
                }
            }
        }
    } else
#endif // SDL_USE_LIBUDEV
    {
#ifdef HAVE_INOTIFY
        inotify_fd = SDL_inotify_init1();

        if (inotify_fd < 0) {
            SDL_LogWarn(SDL_LOG_CATEGORY_INPUT,
                        "Unable to initialize inotify, falling back to polling: %s",
                        strerror(errno));
            return;
        }

        /* We need to watch for attribute changes in addition to
         * creation, because when a device is first created, it has
         * permissions that we can't read. When udev chmods it to
         * something that we maybe *can* read, we'll get an
         * IN_ATTRIB event to tell us. */
        if (inotify_add_watch(inotify_fd, "/dev",
                              IN_CREATE | IN_DELETE | IN_MOVE | IN_ATTRIB) < 0) {
            close(inotify_fd);
            inotify_fd = -1;
            SDL_LogWarn(SDL_LOG_CATEGORY_INPUT,
                        "Unable to add inotify watch, falling back to polling: %s",
                        strerror(errno));
            return;
        }

        SDL_HIDAPI_discovery.m_bCanGetNotifications = true;
#endif // HAVE_INOTIFY
    }
}

static void HIDAPI_UpdateDiscovery(void)
{
    if (!SDL_HIDAPI_discovery.m_bInitialized) {
        HIDAPI_InitializeDiscovery();
    }

    if (!SDL_HIDAPI_discovery.m_bCanGetNotifications) {
        const Uint32 SDL_HIDAPI_DETECT_INTERVAL_MS = 3000; // Update every 3 seconds
        Uint64 now = SDL_GetTicks();
        if (!SDL_HIDAPI_discovery.m_unLastDetect || now >= (SDL_HIDAPI_discovery.m_unLastDetect + SDL_HIDAPI_DETECT_INTERVAL_MS)) {
            ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
            SDL_HIDAPI_discovery.m_unLastDetect = now;
        }
        return;
    }

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
#if 0 // just let the usual SDL_PumpEvents loop dispatch these, fixing bug 4286. --ryan.
    // We'll only get messages on the same thread that created the window
    if (SDL_GetCurrentThreadID() == SDL_HIDAPI_discovery.m_nThreadID) {
        MSG msg;
        while (PeekMessage(&msg, SDL_HIDAPI_discovery.m_hwndMsg, 0, 0, PM_NOREMOVE)) {
            if (GetMessageA(&msg, SDL_HIDAPI_discovery.m_hwndMsg, 0, 0) != 0) {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }
    }
#endif
#endif // defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)

#ifdef SDL_PLATFORM_MACOS
    if (SDL_HIDAPI_discovery.m_notificationPort) {
        struct
        {
            mach_msg_header_t hdr;
            char payload[4096];
        } msg;
        while (mach_msg(&msg.hdr, MACH_RCV_MSG | MACH_RCV_TIMEOUT, 0, sizeof(msg), SDL_HIDAPI_discovery.m_notificationMach, 0, MACH_PORT_NULL) == KERN_SUCCESS) {
            IODispatchCalloutFromMessage(NULL, &msg.hdr, SDL_HIDAPI_discovery.m_notificationPort);
        }
    }
#endif

#ifdef SDL_USE_LIBUDEV
    if (linux_enumeration_method == ENUMERATION_LIBUDEV) {
        if (SDL_HIDAPI_discovery.m_nUdevFd >= 0) {
            /* Drain all notification events.
             * We don't expect a lot of device notifications so just
             * do a new discovery on any kind or number of notifications.
             * This could be made more restrictive if necessary.
             */
            for (;;) {
                struct pollfd PollUdev;
                struct udev_device *pUdevDevice;

                PollUdev.fd = SDL_HIDAPI_discovery.m_nUdevFd;
                PollUdev.events = POLLIN;
                if (poll(&PollUdev, 1, 0) != 1) {
                    break;
                }

                pUdevDevice = usyms->udev_monitor_receive_device(SDL_HIDAPI_discovery.m_pUdevMonitor);
                if (pUdevDevice) {
                    const char *action = NULL;
                    action = usyms->udev_device_get_action(pUdevDevice);
                    if (action == NULL || SDL_strcmp(action, "add") == 0 || SDL_strcmp(action, "remove") == 0) {
                        ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
                    }
                    usyms->udev_device_unref(pUdevDevice);
                }
            }
        }
    } else
#endif // SDL_USE_LIBUDEV
    {
#ifdef HAVE_INOTIFY
        if (inotify_fd >= 0) {
            union
            {
                struct inotify_event event;
                char storage[4096];
                char enough_for_inotify[sizeof(struct inotify_event) + NAME_MAX + 1];
            } buf;
            ssize_t bytes;
            size_t remain = 0;
            size_t len;

            bytes = read(inotify_fd, &buf, sizeof(buf));

            if (bytes > 0) {
                remain = (size_t)bytes;
            }

            while (remain > 0) {
                if (buf.event.len > 0) {
                    if (StrHasPrefix(buf.event.name, "hidraw") &&
                        StrIsInteger(buf.event.name + SDL_strlen("hidraw"))) {
                        ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
                        /* We found an hidraw change. We still continue to
                         * drain the inotify fd to avoid leaving old
                         * notifications in the queue. */
                    }
                }

                len = sizeof(struct inotify_event) + buf.event.len;
                remain -= len;

                if (remain != 0) {
                    SDL_memmove(&buf.storage[0], &buf.storage[len], remain);
                }
            }
        }
#endif // HAVE_INOTIFY
    }
}

static void HIDAPI_ShutdownDiscovery(void)
{
    if (!SDL_HIDAPI_discovery.m_bInitialized) {
        return;
    }

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
    if (SDL_HIDAPI_discovery.m_hNotify) {
        UnregisterDeviceNotification(SDL_HIDAPI_discovery.m_hNotify);
    }

    if (SDL_HIDAPI_discovery.m_hwndMsg) {
        DestroyWindow(SDL_HIDAPI_discovery.m_hwndMsg);
    }

    UnregisterClassA(SDL_HIDAPI_discovery.m_wndClass.lpszClassName, SDL_HIDAPI_discovery.m_wndClass.hInstance);
#endif

#ifdef SDL_PLATFORM_MACOS
    if (SDL_HIDAPI_discovery.m_notificationPort) {
        IONotificationPortDestroy(SDL_HIDAPI_discovery.m_notificationPort);
    }
#endif

#ifdef SDL_USE_LIBUDEV
    if (linux_enumeration_method == ENUMERATION_LIBUDEV) {
        if (usyms) {
            if (SDL_HIDAPI_discovery.m_pUdevMonitor) {
                usyms->udev_monitor_unref(SDL_HIDAPI_discovery.m_pUdevMonitor);
            }
            if (SDL_HIDAPI_discovery.m_pUdev) {
                usyms->udev_unref(SDL_HIDAPI_discovery.m_pUdev);
            }
            SDL_UDEV_ReleaseUdevSyms();
            usyms = NULL;
        }
    } else
#endif // SDL_USE_LIBUDEV
    {
#ifdef HAVE_INOTIFY
        if (inotify_fd >= 0) {
            close(inotify_fd);
            inotify_fd = -1;
        }
#endif
    }

    SDL_HIDAPI_discovery.m_bInitialized = false;
}

// Platform HIDAPI Implementation

#define HIDAPI_USING_SDL_RUNTIME
#define HIDAPI_IGNORE_DEVICE(BUS, VID, PID, USAGE_PAGE, USAGE) \
        SDL_HIDAPI_ShouldIgnoreDevice(BUS, VID, PID, USAGE_PAGE, USAGE)

struct PLATFORM_hid_device_;
typedef struct PLATFORM_hid_device_ PLATFORM_hid_device;

#define api_version                  PLATFORM_api_version
#define create_device_info_for_device PLATFORM_create_device_info_for_device
#define free_hid_device              PLATFORM_free_hid_device
#define hid_close                    PLATFORM_hid_close
#define hid_device                   PLATFORM_hid_device
#define hid_device_                  PLATFORM_hid_device_
#define hid_enumerate                PLATFORM_hid_enumerate
#define hid_error                    PLATFORM_hid_error
#define hid_exit                     PLATFORM_hid_exit
#define hid_free_enumeration         PLATFORM_hid_free_enumeration
#define hid_get_device_info          PLATFORM_hid_get_device_info
#define hid_get_feature_report       PLATFORM_hid_get_feature_report
#define hid_get_indexed_string       PLATFORM_hid_get_indexed_string
#define hid_get_input_report         PLATFORM_hid_get_input_report
#define hid_get_manufacturer_string  PLATFORM_hid_get_manufacturer_string
#define hid_get_product_string       PLATFORM_hid_get_product_string
#define hid_get_report_descriptor    PLATFORM_hid_get_report_descriptor
#define hid_get_serial_number_string PLATFORM_hid_get_serial_number_string
#define hid_init                     PLATFORM_hid_init
#define hid_open_path                PLATFORM_hid_open_path
#define hid_open                     PLATFORM_hid_open
#define hid_read                     PLATFORM_hid_read
#define hid_read_timeout             PLATFORM_hid_read_timeout
#define hid_send_feature_report      PLATFORM_hid_send_feature_report
#define hid_set_nonblocking          PLATFORM_hid_set_nonblocking
#define hid_version                  PLATFORM_hid_version
#define hid_version_str              PLATFORM_hid_version_str
#define hid_write                    PLATFORM_hid_write
#define input_report                 PLATFORM_input_report
#define make_path                    PLATFORM_make_path
#define new_hid_device               PLATFORM_new_hid_device
#define read_thread                  PLATFORM_read_thread
#define return_data                  PLATFORM_return_data

#ifdef SDL_PLATFORM_LINUX
#include "SDL_hidapi_linux.h"
#elif defined(SDL_PLATFORM_NETBSD)
#include "SDL_hidapi_netbsd.h"
#elif defined(SDL_PLATFORM_MACOS)
#include "SDL_hidapi_mac.h"
#elif defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
#include "SDL_hidapi_windows.h"
#elif defined(SDL_PLATFORM_ANDROID)
#include "SDL_hidapi_android.h"
#elif defined(SDL_PLATFORM_IOS) || defined(SDL_PLATFORM_TVOS)
#include "SDL_hidapi_ios.h"
#endif

#undef api_version
#undef create_device_info_for_device
#undef free_hid_device
#undef hid_close
#undef hid_device
#undef hid_device_
#undef hid_enumerate
#undef hid_error
#undef hid_exit
#undef hid_free_enumeration
#undef hid_get_device_info
#undef hid_get_feature_report
#undef hid_get_indexed_string
#undef hid_get_input_report
#undef hid_get_manufacturer_string
#undef hid_get_product_string
#undef hid_get_report_descriptor
#undef hid_get_serial_number_string
#undef hid_init
#undef hid_open
#undef hid_open_path
#undef hid_read
#undef hid_read_timeout
#undef hid_send_feature_report
#undef hid_set_nonblocking
#undef hid_version
#undef hid_version_str
#undef hid_write
#undef input_report
#undef make_path
#undef new_hid_device
#undef read_thread
#undef return_data

#ifdef SDL_JOYSTICK_HIDAPI_STEAMXBOX
#define HAVE_DRIVER_BACKEND 1
#endif

#ifdef HAVE_DRIVER_BACKEND

// DRIVER HIDAPI Implementation

struct DRIVER_hid_device_;
typedef struct DRIVER_hid_device_ DRIVER_hid_device;

#define hid_close                    DRIVER_hid_close
#define hid_device                   DRIVER_hid_device
#define hid_device_                  DRIVER_hid_device_
#define hid_enumerate                DRIVER_hid_enumerate
#define hid_error                    DRIVER_hid_error
#define hid_exit                     DRIVER_hid_exit
#define hid_free_enumeration         DRIVER_hid_free_enumeration
#define hid_get_device_info          DRIVER_hid_get_device_info
#define hid_get_feature_report       DRIVER_hid_get_feature_report
#define hid_get_indexed_string       DRIVER_hid_get_indexed_string
#define hid_get_input_report         DRIVER_hid_get_input_report
#define hid_get_manufacturer_string  DRIVER_hid_get_manufacturer_string
#define hid_get_product_string       DRIVER_hid_get_product_string
#define hid_get_report_descriptor    DRIVER_hid_get_report_descriptor
#define hid_get_serial_number_string DRIVER_hid_get_serial_number_string
#define hid_init                     DRIVER_hid_init
#define hid_open                     DRIVER_hid_open
#define hid_open_path                DRIVER_hid_open_path
#define hid_read                     DRIVER_hid_read
#define hid_read_timeout             DRIVER_hid_read_timeout
#define hid_send_feature_report      DRIVER_hid_send_feature_report
#define hid_set_nonblocking          DRIVER_hid_set_nonblocking
#define hid_write                    DRIVER_hid_write

#ifdef SDL_JOYSTICK_HIDAPI_STEAMXBOX
#include "SDL_hidapi_steamxbox.h"
#else
#error Need a driver hid.c for this platform!
#endif

#undef hid_close
#undef hid_device
#undef hid_device_
#undef hid_enumerate
#undef hid_error
#undef hid_exit
#undef hid_free_enumeration
#undef hid_get_device_info
#undef hid_get_feature_report
#undef hid_get_indexed_string
#undef hid_get_input_report
#undef hid_get_manufacturer_string
#undef hid_get_product_string
#undef hid_get_report_descriptor
#undef hid_get_serial_number_string
#undef hid_init
#undef hid_open
#undef hid_open_path
#undef hid_read
#undef hid_read_timeout
#undef hid_send_feature_report
#undef hid_set_nonblocking
#undef hid_write

#endif // HAVE_DRIVER_BACKEND

#ifdef HAVE_LIBUSB
// libusb HIDAPI Implementation

#include "../misc/SDL_libusb.h"

static SDL_LibUSBContext *libusb_ctx;

#define libusb_init                         libusb_ctx->init
#define libusb_exit                         libusb_ctx->exit
#define libusb_get_device_list              libusb_ctx->get_device_list
#define libusb_free_device_list             libusb_ctx->free_device_list
#define libusb_get_device_descriptor        libusb_ctx->get_device_descriptor
#define libusb_get_active_config_descriptor libusb_ctx->get_active_config_descriptor
#define libusb_get_config_descriptor        libusb_ctx->get_config_descriptor
#define libusb_free_config_descriptor       libusb_ctx->free_config_descriptor
#define libusb_get_bus_number               libusb_ctx->get_bus_number
#define libusb_get_port_numbers             libusb_ctx->get_port_numbers
#define libusb_get_device_address           libusb_ctx->get_device_address
#define libusb_open                         libusb_ctx->open
#define libusb_close                        libusb_ctx->close
#define libusb_get_device                   libusb_ctx->get_device
#define libusb_claim_interface              libusb_ctx->claim_interface
#define libusb_release_interface            libusb_ctx->release_interface
#define libusb_kernel_driver_active         libusb_ctx->kernel_driver_active
#define libusb_detach_kernel_driver         libusb_ctx->detach_kernel_driver
#define libusb_attach_kernel_driver         libusb_ctx->attach_kernel_driver
#define libusb_set_interface_alt_setting    libusb_ctx->set_interface_alt_setting
#define libusb_alloc_transfer               libusb_ctx->alloc_transfer
#define libusb_submit_transfer              libusb_ctx->submit_transfer
#define libusb_cancel_transfer              libusb_ctx->cancel_transfer
#define libusb_free_transfer                libusb_ctx->free_transfer
#define libusb_control_transfer             libusb_ctx->control_transfer
#define libusb_interrupt_transfer           libusb_ctx->interrupt_transfer
#define libusb_bulk_transfer                libusb_ctx->bulk_transfer
#define libusb_handle_events                libusb_ctx->handle_events
#define libusb_handle_events_completed      libusb_ctx->handle_events_completed
#define libusb_error_name                   libusb_ctx->error_name

struct LIBUSB_hid_device_;
typedef struct LIBUSB_hid_device_ LIBUSB_hid_device;

#define free_hid_device              LIBUSB_free_hid_device
#define hid_close                    LIBUSB_hid_close
#define hid_device                   LIBUSB_hid_device
#define hid_device_                  LIBUSB_hid_device_
#define hid_enumerate                LIBUSB_hid_enumerate
#define hid_error                    LIBUSB_hid_error
#define hid_exit                     LIBUSB_hid_exit
#define hid_free_enumeration         LIBUSB_hid_free_enumeration
#define hid_get_device_info          LIBUSB_hid_get_device_info
#define hid_get_feature_report       LIBUSB_hid_get_feature_report
#define hid_get_indexed_string       LIBUSB_hid_get_indexed_string
#define hid_get_input_report         LIBUSB_hid_get_input_report
#define hid_get_manufacturer_string  LIBUSB_hid_get_manufacturer_string
#define hid_get_product_string       LIBUSB_hid_get_product_string
#define hid_get_report_descriptor    LIBUSB_hid_get_report_descriptor
#define hid_get_serial_number_string LIBUSB_hid_get_serial_number_string
#define hid_init                     LIBUSB_hid_init
#define hid_open                     LIBUSB_hid_open
#define hid_open_path                LIBUSB_hid_open_path
#define hid_read                     LIBUSB_hid_read
#define hid_read_timeout             LIBUSB_hid_read_timeout
#define hid_send_feature_report      LIBUSB_hid_send_feature_report
#define hid_set_nonblocking          LIBUSB_hid_set_nonblocking
#define hid_write                    LIBUSB_hid_write
#define hid_version                  LIBUSB_hid_version
#define hid_version_str              LIBUSB_hid_version_str
#define input_report                 LIBUSB_input_report
#define make_path                    LIBUSB_make_path
#define new_hid_device               LIBUSB_new_hid_device
#define read_thread                  LIBUSB_read_thread
#define return_data                  LIBUSB_return_data

#include "SDL_hidapi_libusb.h"

#undef libusb_init
#undef libusb_exit
#undef libusb_get_device_list
#undef libusb_free_device_list
#undef libusb_get_device_descriptor
#undef libusb_get_active_config_descriptor
#undef libusb_get_config_descriptor
#undef libusb_free_config_descriptor
#undef libusb_get_bus_number
#undef libusb_get_port_numbers
#undef libusb_get_device_address
#undef libusb_open
#undef libusb_close
#undef libusb_get_device
#undef libusb_claim_interface
#undef libusb_release_interface
#undef libusb_kernel_driver_active
#undef libusb_detach_kernel_driver
#undef libusb_attach_kernel_driver
#undef libusb_set_interface_alt_setting
#undef libusb_alloc_transfer
#undef libusb_submit_transfer
#undef libusb_cancel_transfer
#undef libusb_free_transfer
#undef libusb_control_transfer
#undef libusb_interrupt_transfer
#undef libusb_bulk_transfer
#undef libusb_handle_events
#undef libusb_handle_events_completed
#undef libusb_error_name

#undef free_hid_device
#undef hid_close
#undef hid_device
#undef hid_device_
#undef hid_enumerate
#undef hid_error
#undef hid_exit
#undef hid_free_enumeration
#undef hid_get_device_info
#undef hid_get_feature_report
#undef hid_get_indexed_string
#undef hid_get_input_report
#undef hid_get_manufacturer_string
#undef hid_get_product_string
#undef hid_get_report_descriptor
#undef hid_get_serial_number_string
#undef hid_init
#undef hid_open
#undef hid_open_path
#undef hid_read
#undef hid_read_timeout
#undef hid_send_feature_report
#undef hid_set_nonblocking
#undef hid_write
#undef input_report
#undef make_path
#undef new_hid_device
#undef read_thread
#undef return_data

/* If the platform has any backend other than libusb, try to avoid using
 * libusb as the main backend for devices, since it detaches drivers and
 * therefore makes devices inaccessible to the rest of the OS.
 *
 * We do this by whitelisting devices we know to be accessible _exclusively_
 * via libusb; these are typically devices that look like HIDs but have a
 * quirk that requires direct access to the hardware.
 */
static const struct {
    Uint16 vendor;
    Uint16 product;
} SDL_libusb_whitelist[] = {
    { USB_VENDOR_NINTENDO, USB_PRODUCT_NINTENDO_GAMECUBE_ADAPTER },
    { USB_VENDOR_NINTENDO, USB_PRODUCT_NINTENDO_SWITCH2_GAMECUBE_CONTROLLER },
    { USB_VENDOR_NINTENDO, USB_PRODUCT_NINTENDO_SWITCH2_JOYCON_LEFT },
    { USB_VENDOR_NINTENDO, USB_PRODUCT_NINTENDO_SWITCH2_JOYCON_RIGHT },
    { USB_VENDOR_NINTENDO, USB_PRODUCT_NINTENDO_SWITCH2_PRO },
};

static bool IsInWhitelist(Uint16 vendor, Uint16 product)
{
    int i;
    for (i = 0; i < SDL_arraysize(SDL_libusb_whitelist); i += 1) {
        if (vendor == SDL_libusb_whitelist[i].vendor &&
            product == SDL_libusb_whitelist[i].product) {
            return true;
        }
    }
    return false;
}

#endif // HAVE_LIBUSB

#endif // !SDL_HIDAPI_DISABLED

#if defined(HAVE_PLATFORM_BACKEND) || defined(HAVE_DRIVER_BACKEND)
// We have another way to get HID devices, so use the whitelist to get devices where libusb is preferred
#define SDL_HINT_HIDAPI_LIBUSB_WHITELIST_DEFAULT true
#else
// libusb is the only way to get HID devices, so don't use the whitelist, get them all
#define SDL_HINT_HIDAPI_LIBUSB_WHITELIST_DEFAULT false
#endif // HAVE_PLATFORM_BACKEND || HAVE_DRIVER_BACKEND

static bool use_libusb_whitelist = SDL_HINT_HIDAPI_LIBUSB_WHITELIST_DEFAULT;

// Shared HIDAPI Implementation

struct hidapi_backend
{
    int (*hid_write)(void *device, const unsigned char *data, size_t length);
    int (*hid_read_timeout)(void *device, unsigned char *data, size_t length, int milliseconds);
    int (*hid_read)(void *device, unsigned char *data, size_t length);
    int (*hid_set_nonblocking)(void *device, int nonblock);
    int (*hid_send_feature_report)(void *device, const unsigned char *data, size_t length);
    int (*hid_get_feature_report)(void *device, unsigned char *data, size_t length);
    int (*hid_get_input_report)(void *device, unsigned char *data, size_t length);
    void (*hid_close)(void *device);
    int (*hid_get_manufacturer_string)(void *device, wchar_t *string, size_t maxlen);
    int (*hid_get_product_string)(void *device, wchar_t *string, size_t maxlen);
    int (*hid_get_serial_number_string)(void *device, wchar_t *string, size_t maxlen);
    int (*hid_get_indexed_string)(void *device, int string_index, wchar_t *string, size_t maxlen);
    struct hid_device_info *(*hid_get_device_info)(void *device);
    int (*hid_get_report_descriptor)(void *device, unsigned char *buf, size_t buf_size);
    const wchar_t *(*hid_error)(void *device);
};

#ifdef HAVE_PLATFORM_BACKEND
static const struct hidapi_backend PLATFORM_Backend = {
    (void *)PLATFORM_hid_write,
    (void *)PLATFORM_hid_read_timeout,
    (void *)PLATFORM_hid_read,
    (void *)PLATFORM_hid_set_nonblocking,
    (void *)PLATFORM_hid_send_feature_report,
    (void *)PLATFORM_hid_get_feature_report,
    (void *)PLATFORM_hid_get_input_report,
    (void *)PLATFORM_hid_close,
    (void *)PLATFORM_hid_get_manufacturer_string,
    (void *)PLATFORM_hid_get_product_string,
    (void *)PLATFORM_hid_get_serial_number_string,
    (void *)PLATFORM_hid_get_indexed_string,
    (void *)PLATFORM_hid_get_device_info,
    (void *)PLATFORM_hid_get_report_descriptor,
    (void *)PLATFORM_hid_error
};
#endif // HAVE_PLATFORM_BACKEND

#ifdef HAVE_DRIVER_BACKEND
static const struct hidapi_backend DRIVER_Backend = {
    (void *)DRIVER_hid_write,
    (void *)DRIVER_hid_read_timeout,
    (void *)DRIVER_hid_read,
    (void *)DRIVER_hid_set_nonblocking,
    (void *)DRIVER_hid_send_feature_report,
    (void *)DRIVER_hid_get_feature_report,
    (void *)DRIVER_hid_get_input_report,
    (void *)DRIVER_hid_close,
    (void *)DRIVER_hid_get_manufacturer_string,
    (void *)DRIVER_hid_get_product_string,
    (void *)DRIVER_hid_get_serial_number_string,
    (void *)DRIVER_hid_get_indexed_string,
    (void *)DRIVER_hid_get_device_info,
    (void *)DRIVER_hid_get_report_descriptor,
    (void *)DRIVER_hid_error
};
#endif // HAVE_DRIVER_BACKEND

#ifdef HAVE_LIBUSB
static const struct hidapi_backend LIBUSB_Backend = {
    (void *)LIBUSB_hid_write,
    (void *)LIBUSB_hid_read_timeout,
    (void *)LIBUSB_hid_read,
    (void *)LIBUSB_hid_set_nonblocking,
    (void *)LIBUSB_hid_send_feature_report,
    (void *)LIBUSB_hid_get_feature_report,
    (void *)LIBUSB_hid_get_input_report,
    (void *)LIBUSB_hid_close,
    (void *)LIBUSB_hid_get_manufacturer_string,
    (void *)LIBUSB_hid_get_product_string,
    (void *)LIBUSB_hid_get_serial_number_string,
    (void *)LIBUSB_hid_get_indexed_string,
    (void *)LIBUSB_hid_get_device_info,
    (void *)LIBUSB_hid_get_report_descriptor,
    (void *)LIBUSB_hid_error
};
#endif // HAVE_LIBUSB

struct SDL_hid_device
{
    void *device;
    const struct hidapi_backend *backend;
    SDL_hid_device_info info;
    SDL_PropertiesID props;
};

#if defined(HAVE_PLATFORM_BACKEND) || defined(HAVE_DRIVER_BACKEND) || defined(HAVE_LIBUSB)

static SDL_hid_device *CreateHIDDeviceWrapper(void *device, const struct hidapi_backend *backend)
{
    SDL_hid_device *wrapper = (SDL_hid_device *)SDL_calloc(1, sizeof(*wrapper));
    SDL_SetObjectValid(wrapper, SDL_OBJECT_TYPE_HIDAPI_DEVICE, true);
    wrapper->device = device;
    wrapper->backend = backend;
    SDL_zero(wrapper->info);
    return wrapper;
}

#endif // HAVE_PLATFORM_BACKEND || HAVE_DRIVER_BACKEND || HAVE_LIBUSB

static void DeleteHIDDeviceWrapper(SDL_hid_device *wrapper)
{
    SDL_SetObjectValid(wrapper, SDL_OBJECT_TYPE_HIDAPI_DEVICE, false);
    SDL_free(wrapper->info.path);
    SDL_free(wrapper->info.serial_number);
    SDL_free(wrapper->info.manufacturer_string);
    SDL_free(wrapper->info.product_string);
    SDL_free(wrapper);
}

#define CHECK_DEVICE_MAGIC(device, result)                          \
    if (!SDL_ObjectValid(device, SDL_OBJECT_TYPE_HIDAPI_DEVICE)) {  \
        SDL_SetError("Invalid device");                             \
        return result;                                              \
    }

#define COPY_IF_EXISTS(var)                \
    if (pSrc->var != NULL) {               \
        pDst->var = SDL_strdup(pSrc->var); \
    } else {                               \
        pDst->var = NULL;                  \
    }
#define WCOPY_IF_EXISTS(var)               \
    if (pSrc->var != NULL) {               \
        pDst->var = SDL_wcsdup(pSrc->var); \
    } else {                               \
        pDst->var = NULL;                  \
    }

static void CopyHIDDeviceInfo(struct hid_device_info *pSrc, struct SDL_hid_device_info *pDst)
{
    COPY_IF_EXISTS(path)
    pDst->vendor_id = pSrc->vendor_id;
    pDst->product_id = pSrc->product_id;
    WCOPY_IF_EXISTS(serial_number)
    pDst->release_number = pSrc->release_number;
    WCOPY_IF_EXISTS(manufacturer_string)
    WCOPY_IF_EXISTS(product_string)
    pDst->usage_page = pSrc->usage_page;
    pDst->usage = pSrc->usage;
    pDst->interface_number = pSrc->interface_number;
    pDst->interface_class = pSrc->interface_class;
    pDst->interface_subclass = pSrc->interface_subclass;
    pDst->interface_protocol = pSrc->interface_protocol;
    pDst->bus_type = (SDL_hid_bus_type)pSrc->bus_type;
    pDst->next = NULL;
}

#undef COPY_IF_EXISTS
#undef WCOPY_IF_EXISTS

static int SDL_hidapi_refcount = 0;
static bool SDL_hidapi_only_controllers;
static char *SDL_hidapi_ignored_devices = NULL;

static void SDLCALL OnlyControllersChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
    SDL_hidapi_only_controllers = SDL_GetStringBoolean(hint, true);
}

static void SDLCALL IgnoredDevicesChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
    SDL_free(SDL_hidapi_ignored_devices);
    if (hint && *hint) {
        SDL_hidapi_ignored_devices = SDL_strdup(hint);
    } else {
        SDL_hidapi_ignored_devices = NULL;
    }
}

bool SDL_HIDAPI_ShouldIgnoreDevice(int bus, Uint16 vendor_id, Uint16 product_id, Uint16 usage_page, Uint16 usage)
{
    // See if there are any devices we should skip in enumeration
    if (SDL_hidapi_only_controllers && usage_page) {
        if (vendor_id == USB_VENDOR_VALVE) {
            // Ignore the mouse/keyboard interface on Steam Controllers
            if (
#ifdef SDL_PLATFORM_WIN32
                // Check the usage page and usage on both USB and Bluetooth
#else
                // Only check the usage page and usage on USB
                bus == HID_API_BUS_USB &&
#endif
                usage_page == USB_USAGEPAGE_GENERIC_DESKTOP &&
                (usage == USB_USAGE_GENERIC_KEYBOARD || usage == USB_USAGE_GENERIC_MOUSE)) {
                return true;
            }
        } else if (vendor_id == USB_VENDOR_FLYDIGI_V1 && product_id == USB_PRODUCT_FLYDIGI_V1_GAMEPAD) {
            if (usage_page == USB_USAGEPAGE_VENDOR_FLYDIGI) {
                return false;
            }
            return true;
        } else if (vendor_id == USB_VENDOR_FLYDIGI_V2 &&
                    (product_id == USB_PRODUCT_FLYDIGI_V2_APEX || product_id == USB_PRODUCT_FLYDIGI_V2_VADER)) {
            if (usage_page == USB_USAGEPAGE_VENDOR_FLYDIGI) {
                return false;
            }
            return true;
        } else if (usage_page == USB_USAGEPAGE_GENERIC_DESKTOP &&
                   (usage == USB_USAGE_GENERIC_JOYSTICK || usage == USB_USAGE_GENERIC_GAMEPAD || usage == USB_USAGE_GENERIC_MULTIAXISCONTROLLER)) {
            // This is a controller
        } else {
            return true;
        }
    }
    if (SDL_hidapi_ignored_devices) {
        char vendor_match[16], product_match[16];
        SDL_snprintf(vendor_match, sizeof(vendor_match), "0x%.4x/0x0000", vendor_id);
        SDL_snprintf(product_match, sizeof(product_match), "0x%.4x/0x%.4x", vendor_id, product_id);
        if (SDL_strcasestr(SDL_hidapi_ignored_devices, vendor_match) ||
            SDL_strcasestr(SDL_hidapi_ignored_devices, product_match)) {
            return true;
        }
    }
    return false;
}

int SDL_hid_init(void)
{
    int attempts = 0, success = 0;

    if (SDL_hidapi_refcount > 0) {
        ++SDL_hidapi_refcount;
        return 0;
    }

    SDL_AddHintCallback(SDL_HINT_HIDAPI_ENUMERATE_ONLY_CONTROLLERS, OnlyControllersChanged, NULL);
    SDL_AddHintCallback(SDL_HINT_HIDAPI_IGNORE_DEVICES, IgnoredDevicesChanged, NULL);

#ifdef SDL_USE_LIBUDEV
    if (!SDL_GetHintBoolean(SDL_HINT_HIDAPI_UDEV, true)) {
        SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
                     "udev disabled by SDL_HINT_HIDAPI_UDEV");
        linux_enumeration_method = ENUMERATION_FALLBACK;
    } else if (SDL_GetSandbox() != SDL_SANDBOX_NONE) {
        SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
                     "Container detected, disabling HIDAPI udev integration");
        linux_enumeration_method = ENUMERATION_FALLBACK;
    } else {
        SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
                     "Using udev for HIDAPI joystick device discovery");
        linux_enumeration_method = ENUMERATION_LIBUDEV;
    }
#endif

    use_libusb_whitelist = SDL_GetHintBoolean(SDL_HINT_HIDAPI_LIBUSB_WHITELIST,
                                              SDL_HINT_HIDAPI_LIBUSB_WHITELIST_DEFAULT);
#ifdef HAVE_LIBUSB
    if (!SDL_GetHintBoolean(SDL_HINT_HIDAPI_LIBUSB, true)) {
        SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
                     "libusb disabled with SDL_HINT_HIDAPI_LIBUSB");
    } else {
        ++attempts;
        if (!SDL_InitLibUSB(&libusb_ctx)) {
            SDL_LogDebug(SDL_LOG_CATEGORY_INPUT, "Couldn't load libusb");
        } else if (LIBUSB_hid_init() < 0) {
            SDL_QuitLibUSB();
            libusb_ctx = NULL;
        } else {
            ++success;
        }
    }
#endif // HAVE_LIBUSB

#ifdef HAVE_PLATFORM_BACKEND
    ++attempts;
#ifdef SDL_PLATFORM_LINUX
    udev_ctx = SDL_UDEV_GetUdevSyms();
#endif // __LINUX __
    if (udev_ctx && PLATFORM_hid_init() == 0) {
        ++success;
    }
#endif // HAVE_PLATFORM_BACKEND

    if (attempts > 0 && success == 0) {
        return -1;
    }

#if defined(SDL_PLATFORM_MACOS) && !defined(SDL_HIDAPI_DISABLED)
    hid_darwin_set_open_exclusive(0);
#endif

    ++SDL_hidapi_refcount;
    return 0;
}

int SDL_hid_exit(void)
{
    int result = 0;

    if (SDL_hidapi_refcount == 0) {
        return 0;
    }
    --SDL_hidapi_refcount;
    if (SDL_hidapi_refcount > 0) {
        return 0;
    }
    SDL_hidapi_refcount = 0;

#ifndef SDL_HIDAPI_DISABLED
    HIDAPI_ShutdownDiscovery();
#endif

#ifdef HAVE_PLATFORM_BACKEND
    if (udev_ctx) {
        result |= PLATFORM_hid_exit();
    }
#ifdef SDL_PLATFORM_LINUX
    SDL_UDEV_ReleaseUdevSyms();
#endif // __LINUX __
#endif // HAVE_PLATFORM_BACKEND

#ifdef HAVE_LIBUSB
    if (libusb_ctx) {
        result |= LIBUSB_hid_exit();
        SDL_QuitLibUSB();
        libusb_ctx = NULL;
    }
#endif // HAVE_LIBUSB

    SDL_RemoveHintCallback(SDL_HINT_HIDAPI_ENUMERATE_ONLY_CONTROLLERS, OnlyControllersChanged, NULL);
    SDL_RemoveHintCallback(SDL_HINT_HIDAPI_IGNORE_DEVICES, IgnoredDevicesChanged, NULL);

    if (SDL_hidapi_ignored_devices) {
        SDL_free(SDL_hidapi_ignored_devices);
        SDL_hidapi_ignored_devices = NULL;
    }

    return result;
}

Uint32 SDL_hid_device_change_count(void)
{
    Uint32 counter = 0;

#ifndef SDL_HIDAPI_DISABLED
    if (SDL_hidapi_refcount == 0 && SDL_hid_init() < 0) {
        return 0;
    }

    HIDAPI_UpdateDiscovery();

    if (SDL_HIDAPI_discovery.m_unDeviceChangeCounter == 0) {
        // Counter wrapped!
        ++SDL_HIDAPI_discovery.m_unDeviceChangeCounter;
    }
    counter = SDL_HIDAPI_discovery.m_unDeviceChangeCounter;

#endif // !SDL_HIDAPI_DISABLED

    return counter;
}

static void AddDeviceToEnumeration(const char *driver_name, struct hid_device_info *dev, struct SDL_hid_device_info **devs, struct SDL_hid_device_info **last)
{
    struct SDL_hid_device_info *new_dev;

#ifdef DEBUG_HIDAPI
    SDL_Log("Adding %s device to enumeration: %ls %ls 0x%.4hx/0x%.4hx/%d",
            driver_name, dev->manufacturer_string, dev->product_string, dev->vendor_id, dev->product_id, dev->interface_number);
#else
    (void)driver_name;
#endif

    new_dev = (struct SDL_hid_device_info *)SDL_malloc(sizeof(struct SDL_hid_device_info));
    if (new_dev == NULL) {
        // Don't bother returning an error, get as many devices as possible
        return;
    }
    CopyHIDDeviceInfo(dev, new_dev);

    if ((*last) != NULL) {
        (*last)->next = new_dev;
    } else {
        *devs = new_dev;
    }
    *last = new_dev;
}

#if defined(HAVE_LIBUSB) || defined(HAVE_PLATFORM_BACKEND)
static void RemoveDeviceFromEnumeration(const char *driver_name, struct hid_device_info *dev, struct hid_device_info **devs, void (*free_device_info)(struct hid_device_info *))
{
    struct hid_device_info *last = NULL, *curr, *next;

    for (curr = *devs; curr; curr = next) {
        next = curr->next;

        if (dev->vendor_id == curr->vendor_id &&
            dev->product_id == curr->product_id &&
            (dev->interface_number < 0 || curr->interface_number < 0 || dev->interface_number == curr->interface_number)) {
#ifdef DEBUG_HIDAPI
            SDL_Log("Skipping %s device: %ls %ls 0x%.4hx/0x%.4hx/%d",
                    driver_name, curr->manufacturer_string, curr->product_string, curr->vendor_id, curr->product_id, curr->interface_number);
#else
            (void)driver_name;
#endif
            if (last) {
                last->next = next;
            } else {
                *devs = next;
            }

            curr->next = NULL;
            free_device_info(curr);
            continue;
        }
        last = curr;
    }
}
#endif // HAVE_LIBUSB || HAVE_PLATFORM_BACKEND

#ifdef HAVE_LIBUSB
static void RemoveNonWhitelistedDevicesFromEnumeration(struct hid_device_info **devs, void (*free_device_info)(struct hid_device_info *))
{
    struct hid_device_info *last = NULL, *curr, *next;

    for (curr = *devs; curr; curr = next) {
        next = curr->next;

        if (!IsInWhitelist(curr->vendor_id, curr->product_id)) {
#ifdef DEBUG_HIDAPI
            SDL_Log("Device was not in libusb whitelist, skipping: %ls %ls 0x%.4hx/0x%.4hx/%d",
                    curr->manufacturer_string, curr->product_string, curr->vendor_id, curr->product_id, curr->interface_number);
#endif
            if (last) {
                last->next = next;
            } else {
                *devs = next;
            }

            curr->next = NULL;
            free_device_info(curr);
            continue;
        }
        last = curr;
    }
}
#endif // HAVE_LIBUSB

struct SDL_hid_device_info *SDL_hid_enumerate(unsigned short vendor_id, unsigned short product_id)
{
    struct hid_device_info *driver_devs = NULL;
    struct hid_device_info *usb_devs = NULL;
    struct hid_device_info *raw_devs = NULL;
    struct hid_device_info *dev;
    struct SDL_hid_device_info *devs = NULL, *last = NULL;

    if (SDL_hidapi_refcount == 0 && SDL_hid_init() < 0) {
        return NULL;
    }

    // Collect the available devices
#ifdef HAVE_DRIVER_BACKEND
    driver_devs = DRIVER_hid_enumerate(vendor_id, product_id);
#endif

#ifdef HAVE_LIBUSB
    if (libusb_ctx) {
        usb_devs = LIBUSB_hid_enumerate(vendor_id, product_id);

        if (use_libusb_whitelist) {
            RemoveNonWhitelistedDevicesFromEnumeration(&usb_devs, LIBUSB_hid_free_enumeration);
        }
    }
#endif // HAVE_LIBUSB

#ifdef HAVE_PLATFORM_BACKEND
    if (udev_ctx) {
        raw_devs = PLATFORM_hid_enumerate(vendor_id, product_id);
    }
#endif

    // Highest priority are custom driver devices
    for (dev = driver_devs; dev; dev = dev->next) {
        AddDeviceToEnumeration("driver", dev, &devs, &last);
#ifdef HAVE_LIBUSB
        RemoveDeviceFromEnumeration("libusb", dev, &usb_devs, LIBUSB_hid_free_enumeration);
#endif
#ifdef HAVE_PLATFORM_BACKEND
        RemoveDeviceFromEnumeration("raw", dev, &raw_devs, PLATFORM_hid_free_enumeration);
#endif
    }

    // If whitelist is in effect, libusb has priority, otherwise raw devices do
    if (use_libusb_whitelist) {
        for (dev = usb_devs; dev; dev = dev->next) {
            AddDeviceToEnumeration("libusb", dev, &devs, &last);
#ifdef HAVE_PLATFORM_BACKEND
            RemoveDeviceFromEnumeration("raw", dev, &raw_devs, PLATFORM_hid_free_enumeration);
#endif
        }
        for (dev = raw_devs; dev; dev = dev->next) {
            AddDeviceToEnumeration("platform", dev, &devs, &last);
        }
    } else {
        for (dev = raw_devs; dev; dev = dev->next) {
            AddDeviceToEnumeration("raw", dev, &devs, &last);
#ifdef HAVE_LIBUSB
            RemoveDeviceFromEnumeration("libusb", dev, &usb_devs, LIBUSB_hid_free_enumeration);
#endif
        }
        for (dev = usb_devs; dev; dev = dev->next) {
            AddDeviceToEnumeration("libusb", dev, &devs, &last);
        }
    }

#ifdef HAVE_DRIVER_BACKEND
    DRIVER_hid_free_enumeration(driver_devs);
#endif
#ifdef HAVE_LIBUSB
    LIBUSB_hid_free_enumeration(usb_devs);
#endif
#ifdef HAVE_PLATFORM_BACKEND
    PLATFORM_hid_free_enumeration(raw_devs);
#endif

    return devs;
}

void SDL_hid_free_enumeration(struct SDL_hid_device_info *devs)
{
    while (devs) {
        struct SDL_hid_device_info *next = devs->next;
        SDL_free(devs->path);
        SDL_free(devs->serial_number);
        SDL_free(devs->manufacturer_string);
        SDL_free(devs->product_string);
        SDL_free(devs);
        devs = next;
    }
}

SDL_hid_device *SDL_hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
{
#if defined(HAVE_PLATFORM_BACKEND) || defined(HAVE_DRIVER_BACKEND) || defined(HAVE_LIBUSB)
    void *pDevice = NULL;

    if (SDL_hidapi_refcount == 0 && SDL_hid_init() < 0) {
        return NULL;
    }

#ifdef HAVE_PLATFORM_BACKEND
    if (udev_ctx) {
        pDevice = PLATFORM_hid_open(vendor_id, product_id, serial_number);
        if (pDevice != NULL) {
            return CreateHIDDeviceWrapper(pDevice, &PLATFORM_Backend);
        }
    }
#endif // HAVE_PLATFORM_BACKEND

#ifdef HAVE_DRIVER_BACKEND
    pDevice = DRIVER_hid_open(vendor_id, product_id, serial_number);
    if (pDevice != NULL) {
        return CreateHIDDeviceWrapper(pDevice, &DRIVER_Backend);
    }
#endif // HAVE_DRIVER_BACKEND

#ifdef HAVE_LIBUSB
    if (libusb_ctx) {
        pDevice = LIBUSB_hid_open(vendor_id, product_id, serial_number);
        if (pDevice != NULL) {
            SDL_hid_device *dev = CreateHIDDeviceWrapper(pDevice, &LIBUSB_Backend);
            SDL_SetPointerProperty(SDL_hid_get_properties(dev), SDL_PROP_HIDAPI_LIBUSB_DEVICE_HANDLE_POINTER, ((LIBUSB_hid_device *)pDevice)->device_handle);
            return dev;
        }
    }
#endif // HAVE_LIBUSB

#endif // HAVE_PLATFORM_BACKEND || HAVE_DRIVER_BACKEND || HAVE_LIBUSB

    return NULL;
}

SDL_hid_device *SDL_hid_open_path(const char *path)
{
#if defined(HAVE_PLATFORM_BACKEND) || defined(HAVE_DRIVER_BACKEND) || defined(HAVE_LIBUSB)
    void *pDevice = NULL;

    if (SDL_hidapi_refcount == 0 && SDL_hid_init() < 0) {
        return NULL;
    }

#ifdef HAVE_PLATFORM_BACKEND
    if (udev_ctx) {
        pDevice = PLATFORM_hid_open_path(path);
        if (pDevice != NULL) {
            return CreateHIDDeviceWrapper(pDevice, &PLATFORM_Backend);
        }
    }
#endif // HAVE_PLATFORM_BACKEND

#ifdef HAVE_DRIVER_BACKEND
    pDevice = DRIVER_hid_open_path(path);
    if (pDevice != NULL) {
        return CreateHIDDeviceWrapper(pDevice, &DRIVER_Backend);
    }
#endif // HAVE_DRIVER_BACKEND

#ifdef HAVE_LIBUSB
    if (libusb_ctx) {
        pDevice = LIBUSB_hid_open_path(path);
        if (pDevice != NULL) {
            SDL_hid_device *dev = CreateHIDDeviceWrapper(pDevice, &LIBUSB_Backend);
            SDL_SetPointerProperty(SDL_hid_get_properties(dev), SDL_PROP_HIDAPI_LIBUSB_DEVICE_HANDLE_POINTER, ((LIBUSB_hid_device *)pDevice)->device_handle);
            return dev;
        }
    }
#endif // HAVE_LIBUSB

#endif // HAVE_PLATFORM_BACKEND || HAVE_DRIVER_BACKEND || HAVE_LIBUSB

    return NULL;
}

SDL_PropertiesID SDL_hid_get_properties(SDL_hid_device *device)
{
    CHECK_DEVICE_MAGIC(device, 0);

    if (!device->props) {
        device->props = SDL_CreateProperties();
    }
    return device->props;
}

int SDL_hid_write(SDL_hid_device *device, const unsigned char *data, size_t length)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_write(device->device, data, length);
}

int SDL_hid_read_timeout(SDL_hid_device *device, unsigned char *data, size_t length, int milliseconds)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_read_timeout(device->device, data, length, milliseconds);
}

int SDL_hid_read(SDL_hid_device *device, unsigned char *data, size_t length)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_read(device->device, data, length);
}

int SDL_hid_set_nonblocking(SDL_hid_device *device, int nonblock)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_set_nonblocking(device->device, nonblock);
}

int SDL_hid_send_feature_report(SDL_hid_device *device, const unsigned char *data, size_t length)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_send_feature_report(device->device, data, length);
}

int SDL_hid_get_feature_report(SDL_hid_device *device, unsigned char *data, size_t length)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_feature_report(device->device, data, length);
}

int SDL_hid_get_input_report(SDL_hid_device *device, unsigned char *data, size_t length)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_input_report(device->device, data, length);
}

int SDL_hid_close(SDL_hid_device *device)
{
    CHECK_DEVICE_MAGIC(device, -1);

    device->backend->hid_close(device->device);
    SDL_DestroyProperties(device->props);
    DeleteHIDDeviceWrapper(device);
    return 0;
}

int SDL_hid_get_manufacturer_string(SDL_hid_device *device, wchar_t *string, size_t maxlen)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_manufacturer_string(device->device, string, maxlen);
}

int SDL_hid_get_product_string(SDL_hid_device *device, wchar_t *string, size_t maxlen)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_product_string(device->device, string, maxlen);
}

int SDL_hid_get_serial_number_string(SDL_hid_device *device, wchar_t *string, size_t maxlen)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_serial_number_string(device->device, string, maxlen);
}

int SDL_hid_get_indexed_string(SDL_hid_device *device, int string_index, wchar_t *string, size_t maxlen)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_indexed_string(device->device, string_index, string, maxlen);
}

SDL_hid_device_info *SDL_hid_get_device_info(SDL_hid_device *device)
{
    struct hid_device_info *info;

    CHECK_DEVICE_MAGIC(device, NULL);

    info = device->backend->hid_get_device_info(device->device);
    if (info) {
        CopyHIDDeviceInfo(info, &device->info);
        return &device->info;
    } else {
        return NULL;
    }
}

int SDL_hid_get_report_descriptor(SDL_hid_device *device, unsigned char *buf, size_t buf_size)
{
    CHECK_DEVICE_MAGIC(device, -1);

    return device->backend->hid_get_report_descriptor(device->device, buf, buf_size);
}

void SDL_hid_ble_scan(bool active)
{
#if !defined(SDL_HIDAPI_DISABLED) && (defined(SDL_PLATFORM_IOS) || defined(SDL_PLATFORM_TVOS))
    extern void hid_ble_scan(int bStart);
    hid_ble_scan(active);
#endif
}