source: mainline/uspace/lib/usbvirt/src/stdreq.c@ a943106

#include "private.h"
#include <usb/request.h>
#include <assert.h>
#include <errno.h>

void usbvirt_control_reply_helper(const usb_device_request_setup_packet_t *setup_packet,
    uint8_t *data, size_t *act_size,
    void *actual_data, size_t actual_data_size)
{
        size_t expected_size = setup_packet->length;
        if (expected_size < actual_data_size) {
                actual_data_size = expected_size;
        }

        memcpy(data, actual_data, actual_data_size);

        if (act_size != NULL) {
                *act_size = actual_data_size;
        }
}

/** GET_DESCRIPTOR handler. */
static int req_get_descriptor(usbvirt_device_t *device,
    const usb_device_request_setup_packet_t *setup_packet, uint8_t *data, size_t *act_size)
{
        uint8_t type = setup_packet->value_high;
        uint8_t index = setup_packet->value_low;

        /*
         * Standard device descriptor.
         */
        if ((type == USB_DESCTYPE_DEVICE) && (index == 0)) {
                if (device->descriptors && device->descriptors->device) {
                        usbvirt_control_reply_helper(setup_packet, data, act_size,
                            device->descriptors->device,
                            device->descriptors->device->length);
                        return EOK;
                } else {
                        return EFORWARD;
                }
        }

        /*
         * Configuration descriptor together with interface, endpoint and
         * class-specific descriptors.
         */
        if (type == USB_DESCTYPE_CONFIGURATION) {
                if (!device->descriptors) {
                        return EFORWARD;
                }
                if (index >= device->descriptors->configuration_count) {
                        return EFORWARD;
                }
                /* Copy the data. */
                usbvirt_device_configuration_t *config = &device->descriptors
                    ->configuration[index];
                uint8_t *all_data = malloc(config->descriptor->total_length);
                if (all_data == NULL) {
                        return ENOMEM;
                }

                uint8_t *ptr = all_data;
                memcpy(ptr, config->descriptor, config->descriptor->length);
                ptr += config->descriptor->length;
                size_t i;
                for (i = 0; i < config->extra_count; i++) {
                        usbvirt_device_configuration_extras_t *extra
                            = &config->extra[i];
                        memcpy(ptr, extra->data, extra->length);
                        ptr += extra->length;
                }

                usbvirt_control_reply_helper(setup_packet, data, act_size,
                    all_data, config->descriptor->total_length);

                free(all_data);

                return EOK;
        }

        return EFORWARD;
}

static int req_set_address(usbvirt_device_t *device,
    const usb_device_request_setup_packet_t *setup_packet, uint8_t *data, size_t *act_size)
{
        uint16_t new_address = setup_packet->value;
        uint16_t zero1 = setup_packet->index;
        uint16_t zero2 = setup_packet->length;

        if ((zero1 != 0) || (zero2 != 0)) {
                return EINVAL;
        }

        if (new_address > 127) {
                return EINVAL;
        }

        device->address = new_address;

        return EOK;
}

static int req_set_configuration(usbvirt_device_t *device,
    const usb_device_request_setup_packet_t *setup_packet, uint8_t *data, size_t *act_size)
{
        uint16_t configuration_value = setup_packet->value;
        uint16_t zero1 = setup_packet->index;
        uint16_t zero2 = setup_packet->length;

        if ((zero1 != 0) || (zero2 != 0)) {
                return EINVAL;
        }

        /*
         * Configuration value is 1 byte information.
         */
        if (configuration_value > 255) {
                return EINVAL;
        }

        /*
         * Do nothing when in default state. According to specification,
         * this is not specified.
         */
        if (device->state == USBVIRT_STATE_DEFAULT) {
                return EOK;
        }

        usbvirt_device_state_t new_state;
        if (configuration_value == 0) {
                new_state = USBVIRT_STATE_ADDRESS;
        } else {
                // FIXME: check that this configuration exists
                new_state = USBVIRT_STATE_CONFIGURED;
        }

        if (device->ops && device->ops->state_changed) {
                device->ops->state_changed(device, device->state, new_state);
        }
        device->state = new_state;

        return EOK;
}

usbvirt_control_request_handler_t library_handlers[] = {
        {
                .req_direction = USB_DIRECTION_OUT,
                .req_recipient = USB_REQUEST_RECIPIENT_DEVICE,
                .req_type = USB_REQUEST_TYPE_STANDARD,
                .request = USB_DEVREQ_SET_ADDRESS,
                .name = "SetAddress",
                .callback = req_set_address
        },
        {
                .req_direction = USB_DIRECTION_IN,
                .req_recipient = USB_REQUEST_RECIPIENT_DEVICE,
                .req_type = USB_REQUEST_TYPE_STANDARD,
                .request = USB_DEVREQ_GET_DESCRIPTOR,
                .name = "GetDescriptor",
                .callback = req_get_descriptor
        },
        {
                .req_direction = USB_DIRECTION_OUT,
                .req_recipient = USB_REQUEST_RECIPIENT_DEVICE,
                .req_type = USB_REQUEST_TYPE_STANDARD,
                .request = USB_DEVREQ_SET_CONFIGURATION,
                .name = "SetConfiguration",
                .callback = req_set_configuration
        },

        { .callback = NULL }
};