Windows: Enable dynamic selection between WinUSB and UsbDk backends

This commit unifies the two Windows backends into a single project and
enables the user to switch to the UsbDk backend, if available, using the
libusb_set_option() function. All contexts will use the WinUSB backend
by default for backwards compatibility.

With this change, the UsbDk-specific projects are no longer required.

Closes #309

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

1 files changed, 68 insertions, 29 deletions

diff --git a/libusb/os/windows_nt_common.h b/libusb/os/windows_nt_common.h
index d3ac6bc..e155b5d 100644
--- a/libusb/os/windows_nt_common.h
+++ b/libusb/os/windows_nt_common.h
@@ -26,45 +26,84 @@
 
 #pragma once
 
-// Missing from MinGW
-#if !defined(FACILITY_SETUPAPI)
-#define FACILITY_SETUPAPI	15
-#endif
-
-#include <pshpack1.h>
+#include "windows_nt_shared_types.h"
 
-typedef struct USB_CONFIGURATION_DESCRIPTOR {
-  UCHAR  bLength;
-  UCHAR  bDescriptorType;
-  USHORT wTotalLength;
-  UCHAR  bNumInterfaces;
-  UCHAR  bConfigurationValue;
-  UCHAR  iConfiguration;
-  UCHAR  bmAttributes;
-  UCHAR  MaxPower;
-} USB_CONFIGURATION_DESCRIPTOR, *PUSB_CONFIGURATION_DESCRIPTOR;
+ /* Windows versions */
+enum windows_version {
+	WINDOWS_UNDEFINED,
+	WINDOWS_2000,
+	WINDOWS_XP,
+	WINDOWS_2003,	// Also XP x64
+	WINDOWS_VISTA,
+	WINDOWS_7,
+	WINDOWS_8,
+	WINDOWS_8_1,
+	WINDOWS_10,
+	WINDOWS_11_OR_LATER
+};
 
-#include <poppack.h>
-
-typedef struct libusb_device_descriptor USB_DEVICE_DESCRIPTOR, *PUSB_DEVICE_DESCRIPTOR;
+extern enum windows_version windows_version;
 
 /* This call is only available from Vista */
 extern BOOL (WINAPI *pCancelIoEx)(HANDLE, LPOVERLAPPED);
 
-int windows_common_init(struct libusb_context *ctx);
-void windows_common_exit(void);
+struct windows_backend {
+	int (*init)(struct libusb_context *ctx);
+	void (*exit)(struct libusb_context *ctx);
+	int (*get_device_list)(struct libusb_context *ctx,
+		struct discovered_devs **discdevs);
+	int (*open)(struct libusb_device_handle *dev_handle);
+	void (*close)(struct libusb_device_handle *dev_handle);
+	int (*get_device_descriptor)(struct libusb_device *device, unsigned char *buffer);
+	int (*get_active_config_descriptor)(struct libusb_device *device,
+		unsigned char *buffer, size_t len);
+	int (*get_config_descriptor)(struct libusb_device *device,
+		uint8_t config_index, unsigned char *buffer, size_t len);
+	int (*get_config_descriptor_by_value)(struct libusb_device *device,
+		uint8_t bConfigurationValue, unsigned char **buffer);
+	int (*get_configuration)(struct libusb_device_handle *dev_handle, int *config);
+	int (*set_configuration)(struct libusb_device_handle *dev_handle, int config);
+	int (*claim_interface)(struct libusb_device_handle *dev_handle, int interface_number);
+	int (*release_interface)(struct libusb_device_handle *dev_handle, int interface_number);
+	int (*set_interface_altsetting)(struct libusb_device_handle *dev_handle,
+		int interface_number, int altsetting);
+	int (*clear_halt)(struct libusb_device_handle *dev_handle,
+		unsigned char endpoint);
+	int (*reset_device)(struct libusb_device_handle *dev_handle);
+	void (*destroy_device)(struct libusb_device *dev);
+	int (*submit_transfer)(struct usbi_transfer *itransfer);
+	int (*cancel_transfer)(struct usbi_transfer *itransfer);
+	void (*clear_transfer_priv)(struct usbi_transfer *itransfer);
+	int (*copy_transfer_data)(struct usbi_transfer *itransfer, uint32_t io_size);
+	int (*get_transfer_fd)(struct usbi_transfer *itransfer);
+	void (*get_overlapped_result)(struct usbi_transfer *itransfer,
+		DWORD *io_result, DWORD *io_size);
+};
 
-unsigned long htab_hash(const char *str);
-int windows_clock_gettime(int clk_id, struct timespec *tp);
+struct windows_context_priv {
+	const struct windows_backend *backend;
+};
 
-void windows_clear_transfer_priv(struct usbi_transfer *itransfer);
-int windows_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size);
-int windows_get_transfer_fd(struct usbi_transfer *itransfer);
-void windows_get_overlapped_result(struct usbi_transfer *itransfer, DWORD *io_result, DWORD *io_size);
+union windows_device_priv {
+	struct usbdk_device_priv usbdk_priv;
+	struct winusb_device_priv winusb_priv;
+};
 
+union windows_device_handle_priv {
+	struct usbdk_device_handle_priv usbdk_priv;
+	struct winusb_device_handle_priv winusb_priv;
+};
+
+union windows_transfer_priv {
+	struct usbdk_transfer_priv usbdk_priv;
+	struct winusb_transfer_priv winusb_priv;
+};
+
+extern const struct windows_backend usbdk_backend;
+extern const struct windows_backend winusb_backend;
+
+unsigned long htab_hash(const char *str);
 void windows_force_sync_completion(OVERLAPPED *overlapped, ULONG size);
-void windows_handle_callback(struct usbi_transfer *itransfer, uint32_t io_result, uint32_t io_size);
-int windows_handle_events(struct libusb_context *ctx, struct pollfd *fds, POLL_NFDS_TYPE nfds, int num_ready);
 
 #if defined(ENABLE_LOGGING)
 const char *windows_error_str(DWORD error_code);