webusb.c

/*
 * Copyright (c) 2016, Devan Lai
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose with or without fee is hereby granted, provided
 * that the above copyright notice and this permission notice
 * appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <string.h>

#include "usb21_standard.h"
#include "util.h"
#include "webusb.h"

const struct webusb_platform_descriptor webusb_platform_capability_descriptor =
    {.bLength = WEBUSB_PLATFORM_DESCRIPTOR_SIZE,
     .bDescriptorType = USB_DT_DEVICE_CAPABILITY,
     .bDevCapabilityType = USB_DC_PLATFORM,
     .bReserved = 0,
     .platformCapabilityUUID = WEBUSB_UUID,
     .bcdVersion = 0x0100,
     .bVendorCode = WEBUSB_VENDOR_CODE,
     .iLandingPage = 1};

static const char* webusb_https_url;

static enum usbd_request_return_codes webusb_control_vendor_request(
    usbd_device* usbd_dev, struct usb_setup_data* req, uint8_t** buf,
    uint16_t* len, usbd_control_complete_callback* complete) {
  (void)complete;
  (void)usbd_dev;

  wait_random();

  if (req->bRequest != WEBUSB_VENDOR_CODE) {
    return USBD_REQ_NEXT_CALLBACK;
  }

  int status = USBD_REQ_NOTSUPP;
  switch (req->wIndex) {
    case WEBUSB_REQ_GET_URL: {
      struct webusb_url_descriptor* url = (struct webusb_url_descriptor*)(*buf);
      uint16_t index = req->wValue;
      if (index == 0) {
        return USBD_REQ_NOTSUPP;
      }

      if (index == 1) {
        size_t url_len = strlen(webusb_https_url);
        url->bLength = WEBUSB_DT_URL_DESCRIPTOR_SIZE + url_len;
        url->bDescriptorType = WEBUSB_DT_URL;
        url->bScheme = WEBUSB_URL_SCHEME_HTTPS;
        memcpy(&url->URL, webusb_https_url, url_len);
        *len = MIN_8bits(*len, url->bLength);
        status = USBD_REQ_HANDLED;
      } else {
        // TODO: stall instead?
        status = USBD_REQ_NOTSUPP;
      }
      break;
    }
    default: {
      status = USBD_REQ_NOTSUPP;
      break;
    }
  }

  return status;
}

static void webusb_set_config(usbd_device* usbd_dev, uint16_t wValue) {
  (void)wValue;
  usbd_register_control_callback(usbd_dev,
                                 USB_REQ_TYPE_VENDOR | USB_REQ_TYPE_DEVICE,
                                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
                                 webusb_control_vendor_request);
}

void webusb_setup(usbd_device* usbd_dev, const char* https_url) {
  webusb_https_url = https_url;

  usbd_register_set_config_callback(usbd_dev, webusb_set_config);
}