usb_class.h File Reference

Class layer - functions, interfaces, and the usbip_device_class vtable. More...

#include <stdarg.h>
#include "usbip-device.h"

Data Structures
struct	usbip_device_class
	A reusable device class: the descriptors it declares, the callbacks that drive it, and the size of its per-instance state. More...

Macros
#define	USB_DT_CS_INTERFACE
	Class-specific descriptor type codes - CDC, UAC and UVC all use these two values.
#define	USB_DT_CS_ENDPOINT
	class-specific endpoint descriptor

Typedefs
typedef struct usbip_function	usbip_function
	A function: one class instance (>=1 iface)
typedef struct usbip_interface	usbip_interface
	One USB interface (one bInterfaceNumber)
typedef int(*	usbip_function_control_fn) (usbip_function *func, const usb_setup *setup, uint8_t *buf, uint16_t len)
	Class/vendor control handler.

Functions
usbip_function *	usbip_device_add_function (usbip_device *dev)
	Low-level: add a bare function you configure yourself, descriptor by descriptor.
int	usbip_function_add_descriptor (usbip_function *func, const void *descriptor)
	Append a typed descriptor (interface / endpoint / HID / class-specific) to a function, in wire order.
usbip_ep *	usbip_function_add_endpoint (usbip_function *func, const void *ep_descriptor)
	Append an endpoint descriptor and return the pipe it created.
uint8_t	usbip_function_reserve_endpoint (usbip_function *func, uint8_t want_addr)
	Claim an endpoint address now, for an endpoint declared later.
usbip_ep *	usbip_function_endpoint (usbip_function *func, uint8_t addr)
	Fetch one of this function's endpoint pipes by address.
void	usbip_function_on_control (usbip_function *func, usbip_function_control_fn cb)
	Install the class/vendor control handler for an interface.
int	usbip_function_enable_msos (usbip_function *func, const char *compatible, const char *guid)
	Advertise Microsoft OS descriptors for one function of a composite device.
int	usbip_function_enable_winusb (usbip_function *func, const char *guid)
	usbip_function_enable_msos() with the "WINUSB" Compatible ID.
usbip_function *	usbip_device_add_class (usbip_device *dev, const usbip_device_class *cls, const void *params)
	Instantiate a reusable device class onto a device, adding one function.
void *	usbip_function_state (usbip_function *func)
	The function's per-instance state block (sized by usbip_device_class::state_size).
usbip_device *	usbip_function_device (usbip_function *func)
	The device a function belongs to - for device-level setup from a class build (e.g.
int	usbip_function_base_ifnum (usbip_function *func)
	The bInterfaceNumber of this function's first interface.
int	usbip_function_instance (usbip_function *func)
	Which instance of its own class this function is, counting from 0 in add order.
usbip_interface *	usbip_function_add_interface (usbip_function *func, uint8_t cls, uint8_t sub, uint8_t proto)
	Add a USB interface (a fresh bInterfaceNumber, alternate setting 0) to a function.
int	usbip_interface_add_altsetting (usbip_interface *iface, uint8_t alt)
	Add an alternate setting to an interface (same bInterfaceNumber, new bAlternateSetting).
int	usbip_interface_add_descriptor (usbip_interface *iface, const void *descriptor)
	Append a class-specific descriptor to an interface's current alternate setting.
usbip_ep *	usbip_interface_add_endpoint (usbip_interface *iface, const void *ep_descriptor)
	Append an endpoint to an interface's current alternate setting.
int	usbip_interface_number (usbip_interface *iface)
	An interface's bInterfaceNumber.
void	usbip_interface_set_string (usbip_interface *iface, uint8_t istr)
	Set the iInterface string index on the interface's current alternate setting.
void	usbip_function_associate (usbip_function *func, uint8_t count, uint8_t cls, uint8_t sub, uint8_t proto, uint8_t iFunction)
	Emit an Interface Association Descriptor grouping this function's interfaces (opt-in).
void	usbip_class_vlog (void(*emit)(void *user, const char *text), void *user, const char *prefix, const char *fmt, va_list ap)
	Format a log line and hand it to a class module's on_event-style callback.

Detailed Description

Class layer - functions, interfaces, and the usbip_device_class vtable.

Composes a device out of functions (one class instance each, owning one or more interfaces), mirroring the Linux gadget composite framework. Built entirely on the public device-core API (usbip_device.h): descriptor groups, per-interface control/set-alt registration, and per-endpoint data callbacks. The core never references this layer, so a device can also be authored against the core alone.

Conventions: functions return USB_SUCCESS (0) on success and a negative USB_ERROR code on failure; constructors return a pointer or NULL. The prefix names the receiver of the first parameter (usbip_function_*, usbip_interface_*).