Get all the UsbConfigDescriptor for the device configuration

device/usb/usb_device_impl.cc

Index: device/usb/usb_device_impl.cc
diff --git a/device/usb/usb_device_impl.cc b/device/usb/usb_device_impl.cc
index 114e6acaa568fec23630556cd6347d1519aec033..e71e16ce2d78c72916c1b47bd3c1d46279c87c7a 100644
--- a/device/usb/usb_device_impl.cc
+++ b/device/usb/usb_device_impl.cc
@@ -89,6 +89,61 @@ UsbUsageType GetUsageType(const libusb_endpoint_descriptor* descriptor) {
   }
 }
 
+void ConvertConfigDescriptor(const libusb_config_descriptor* platform_config,
+                             UsbConfigDescriptor* configuration) {
+  configuration->configuration_value = platform_config->bConfigurationValue;
+  configuration->self_powered = (platform_config->bmAttributes & 0x40) != 0;
+  configuration->remote_wakeup = (platform_config->bmAttributes & 0x20) != 0;
+  configuration->maximum_power = platform_config->MaxPower * 2;
+
+  for (size_t i = 0; i < platform_config->bNumInterfaces; ++i) {
+    const struct libusb_interface* platform_interface =
+        &platform_config->interface[i];
+    for (int j = 0; j < platform_interface->num_altsetting; ++j) {
+      const struct libusb_interface_descriptor* platform_alt_setting =
+          &platform_interface->altsetting[j];
+      UsbInterfaceDescriptor interface;
+
+      interface.interface_number = platform_alt_setting->bInterfaceNumber;
+      interface.alternate_setting = platform_alt_setting->bAlternateSetting;
+      interface.interface_class = platform_alt_setting->bInterfaceClass;
+      interface.interface_subclass = platform_alt_setting->bInterfaceSubClass;
+      interface.interface_protocol = platform_alt_setting->bInterfaceProtocol;
+
+      interface.endpoints.reserve(platform_alt_setting->bNumEndpoints);
+      for (size_t k = 0; k < platform_alt_setting->bNumEndpoints; ++k) {
+        const struct libusb_endpoint_descriptor* platform_endpoint =
+            &platform_alt_setting->endpoint[k];
+        UsbEndpointDescriptor endpoint;
+
+        endpoint.address = platform_endpoint->bEndpointAddress;
+        endpoint.direction = GetDirection(platform_endpoint);
+        endpoint.maximum_packet_size = platform_endpoint->wMaxPacketSize;
+        endpoint.synchronization_type =
+            GetSynchronizationType(platform_endpoint);
+        endpoint.transfer_type = GetTransferType(platform_endpoint);
+        endpoint.usage_type = GetUsageType(platform_endpoint);
+        endpoint.polling_interval = platform_endpoint->bInterval;
+        endpoint.extra_data = std::vector<uint8_t>(
+            platform_endpoint->extra,
+            platform_endpoint->extra + platform_endpoint->extra_length);
+
+        interface.endpoints.push_back(endpoint);
+      }
+
+      interface.extra_data = std::vector<uint8_t>(
+          platform_alt_setting->extra,
+          platform_alt_setting->extra + platform_alt_setting->extra_length);
+
+      configuration->interfaces.push_back(interface);
+    }
+  }
+
+  configuration->extra_data = std::vector<uint8_t>(
+      platform_config->extra,
+      platform_config->extra + platform_config->extra_length);
+}
+
 }  // namespace
 
 UsbDeviceImpl::UsbDeviceImpl(
@@ -108,7 +163,8 @@ UsbDeviceImpl::UsbDeviceImpl(
       blocking_task_runner_(blocking_task_runner) {
   CHECK(platform_device) << "platform_device cannot be NULL";
   libusb_ref_device(platform_device);
-  RefreshConfiguration();
+  ReadAllConfigurations();
+  RefreshActiveConfiguration();
 }
 
 UsbDeviceImpl::~UsbDeviceImpl() {
@@ -159,9 +215,9 @@ bool UsbDeviceImpl::Close(scoped_refptr<UsbDeviceHandle> handle) {
   return false;
 }
 
-const UsbConfigDescriptor* UsbDeviceImpl::GetConfiguration() {
+const UsbConfigDescriptor* UsbDeviceImpl::GetActiveConfiguration() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  return configuration_.get();
+  return active_configuration_;
 }
 
 void UsbDeviceImpl::OnDisconnect() {
@@ -177,7 +233,33 @@ void UsbDeviceImpl::OnDisconnect() {
   }
 }
 
-void UsbDeviceImpl::RefreshConfiguration() {
+void UsbDeviceImpl::ReadAllConfigurations() {
+  libusb_device_descriptor device_descriptor;
+  int rv = libusb_get_device_descriptor(platform_device_, &device_descriptor);
+  if (rv == LIBUSB_SUCCESS) {
+    uint8_t num_configurations = device_descriptor.bNumConfigurations;
+    configurations_.reserve(num_configurations);
+    for (uint8_t i = 0; i < num_configurations; ++i) {
+      libusb_config_descriptor* platform_config;
+      rv = libusb_get_config_descriptor(platform_device_, i, &platform_config);
+      if (rv != LIBUSB_SUCCESS) {
+        USB_LOG(EVENT) << "Failed to get config descriptor: "
+                       << ConvertPlatformUsbErrorToString(rv);
+        continue;
+      }
+
+      UsbConfigDescriptor config_descriptor;
+      ConvertConfigDescriptor(platform_config, &config_descriptor);
+      configurations_.push_back(config_descriptor);
+      libusb_free_config_descriptor(platform_config);
+    }
+  } else {
+    USB_LOG(EVENT) << "Failed to get device descriptor: "
+                   << ConvertPlatformUsbErrorToString(rv);
+  }
+}
+
+void UsbDeviceImpl::RefreshActiveConfiguration() {
   libusb_config_descriptor* platform_config;
   int rv =
       libusb_get_active_config_descriptor(platform_device_, &platform_config);
@@ -187,58 +269,14 @@ void UsbDeviceImpl::RefreshConfiguration() {
     return;
   }
 
-  configuration_.reset(new UsbConfigDescriptor());
-  configuration_->configuration_value = platform_config->bConfigurationValue;
-  configuration_->self_powered = (platform_config->bmAttributes & 0x40) != 0;
-  configuration_->remote_wakeup = (platform_config->bmAttributes & 0x20) != 0;
-  configuration_->maximum_power = platform_config->MaxPower * 2;
-
-  for (size_t i = 0; i < platform_config->bNumInterfaces; ++i) {
-    const struct libusb_interface* platform_interface =
-        &platform_config->interface[i];
-    for (int j = 0; j < platform_interface->num_altsetting; ++j) {
-      const struct libusb_interface_descriptor* platform_alt_setting =
-          &platform_interface->altsetting[j];
-      UsbInterfaceDescriptor interface;
-
-      interface.interface_number = platform_alt_setting->bInterfaceNumber;
-      interface.alternate_setting = platform_alt_setting->bAlternateSetting;
-      interface.interface_class = platform_alt_setting->bInterfaceClass;
-      interface.interface_subclass = platform_alt_setting->bInterfaceSubClass;
-      interface.interface_protocol = platform_alt_setting->bInterfaceProtocol;
-
-      for (size_t k = 0; k < platform_alt_setting->bNumEndpoints; ++k) {
-        const struct libusb_endpoint_descriptor* platform_endpoint =
-            &platform_alt_setting->endpoint[k];
-        UsbEndpointDescriptor endpoint;
-
-        endpoint.address = platform_endpoint->bEndpointAddress;
-        endpoint.direction = GetDirection(platform_endpoint);
-        endpoint.maximum_packet_size = platform_endpoint->wMaxPacketSize;
-        endpoint.synchronization_type =
-            GetSynchronizationType(platform_endpoint);
-        endpoint.transfer_type = GetTransferType(platform_endpoint);
-        endpoint.usage_type = GetUsageType(platform_endpoint);
-        endpoint.polling_interval = platform_endpoint->bInterval;
-        endpoint.extra_data = std::vector<uint8_t>(
-            platform_endpoint->extra,
-            platform_endpoint->extra + platform_endpoint->extra_length);
-
-        interface.endpoints.push_back(endpoint);
-      }
-
-      interface.extra_data = std::vector<uint8_t>(
-          platform_alt_setting->extra,
-          platform_alt_setting->extra + platform_alt_setting->extra_length);
-
-      configuration_->interfaces.push_back(interface);
+  active_configuration_ = nullptr;
+  for (const auto& config : configurations_) {
+    if (config.configuration_value == platform_config->bConfigurationValue) {
+      active_configuration_ = &config;
+      break;
     }
   }
 
-  configuration_->extra_data = std::vector<uint8_t>(
-      platform_config->extra,
-      platform_config->extra + platform_config->extra_length);
-
   libusb_free_config_descriptor(platform_config);
 }