usb_drv: generate a device list report

The report lists all connected devices and gets updated when devices are
added or removed.

Example report:

<devices>
    <device vendor_id="0x17ef" product_id="0x4816"/>
    <device vendor_id="0x0a5c" product_id="0x217f"/>
    <device vendor_id="0x8087" product_id="0x0020"/>
    <device vendor_id="0x8087" product_id="0x0020"/>
    <device vendor_id="0x1d6b" product_id="0x0002"/>
    <device vendor_id="0x1d6b" product_id="0x0002"/>
</devices>

There is no distinction yet for multiple devices of the same type.

The report is named "devices" and an example policy for 'report_rom' would
look like:

<policy label="vbox -> usb_devices" report="usb_drv -> devices"/>

The report only gets generated if enabled in the 'usb_drv' configuration:

<config>
    <raw>
        <report devices="yes"/>
    </raw>
</config>

Fixes #1506

repos/dde_linux/README

@@ -178,3 +178,35 @@ component can control the wireless driver. An example therefore is the Qt
 based component in 'src/app/qt_wifi_connect'.
 
 Currently only WPA/WPA2 protection using a pre-shared key is supported.
+
+RAW
+~~~
+
+Allows raw access to USB devices via the 'Usb' session interface.
+
+Configuration snippet:
+
+!<start name="usb_drv">
+!  <resource name="RAM" quantum="8M"/>
+!  <provides><service name="Usb"/></provides>
+!  <config uhci="yes" ehci="yes" xhci="yes">
+!    <raw>
+!        <report devices="yes"/>
+!    </raw>
+!  </config>
+!</start>
+
+The optional 'devices' report lists the connected devices and gets updated when devices are added or removed.
+
+Example report:
+
+<devices>
+    <device vendor_id="0x17ef" product_id="0x4816"/>
+    <device vendor_id="0x0a5c" product_id="0x217f"/>
+    <device vendor_id="0x8087" product_id="0x0020"/>
+    <device vendor_id="0x8087" product_id="0x0020"/>
+    <device vendor_id="0x1d6b" product_id="0x0002"/>
+    <device vendor_id="0x1d6b" product_id="0x0002"/>
+</devices>
+
+There is no distinction yet for multiple devices of the same type.

repos/dde_linux/src/lib/usb/dummies.c

@@ -241,12 +241,8 @@ int kthread_stop(struct task_struct *k) { TRACE; return 0; }
  ** linux/notifier.h **
  **********************/
 
-int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
-                                     struct notifier_block *nb) { TRACE; return 0; }
 int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
                                        struct notifier_block *nb) { TRACE; return 0; }
-int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
-                                 unsigned long val, void *v) { TRACE; return 0; }
 int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
                                    struct notifier_block *nb) { TRACE; return 0; }
 int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,

repos/dde_linux/src/lib/usb/include/lx_emul.h

@@ -1337,6 +1337,13 @@ enum {
 
 struct notifier_block {
 	int (*notifier_call)(struct notifier_block *, unsigned long, void *);
+	struct notifier_block *next;
+	int                    priority;
+};
+
+struct raw_notifier_head
+{
+	struct notifier_block *head;
 };
 
 struct atomic_notifier_head {

repos/dde_linux/src/lib/usb/include/platform.h

@@ -43,6 +43,9 @@ struct Services
 	unsigned long screen_width  = 0;
 	unsigned long screen_height = 0;
 
+	/* report generation */
+	bool raw_report_device_list = false;
+
 	Services()
 	{
 		using namespace Genode;
@@ -79,8 +82,13 @@ struct Services
 		}
 
 		try {
-			config()->xml_node().sub_node("raw");
+			Genode::Xml_node node_raw = config()->xml_node().sub_node("raw");
 			raw = true;
+
+			try {
+				Genode::Xml_node node_report = node_raw.sub_node("report");
+				raw_report_device_list = node_report.attribute("devices").has_value("yes");
+			} catch (...) { }
 		} catch (Xml_node::Nonexistent_sub_node) {
 			PDBG("No <raw> config node found - not starting external USB service");
 		}

repos/dde_linux/src/lib/usb/include/signal.h

@@ -100,7 +100,7 @@ namespace Nic
 
 namespace Raw
 {
-	void init(Server::Entrypoint &ep);
+	void init(Server::Entrypoint &ep, bool report_device_list);
 }
 
 #endif /* _SIGNAL_H_ */

repos/dde_linux/src/lib/usb/lx_emul.cc

@@ -1299,3 +1299,61 @@ int utf16s_to_utf8s(const wchar_t *pwcs, int len,
 
 	return 2 * length;
 }
+
+/**********************
+ ** linux/notifier.h **
+ **********************/
+
+int raw_notifier_chain_register(struct raw_notifier_head *nh,
+                                struct notifier_block *n)
+{
+	struct notifier_block *nl = nh->head;
+	struct notifier_block *pr = 0;
+	while (nl) {
+		if (n->priority > nl->priority)
+			break;
+		pr = nl;
+		nl = nl->next;
+	}
+
+	n->next = nl;
+	if (pr)
+		pr->next = n;
+	else
+		nh->head = n;
+
+	return 0;
+}
+
+
+int raw_notifier_call_chain(struct raw_notifier_head *nh,
+                            unsigned long val, void *v)
+{
+	int ret = NOTIFY_DONE;
+	struct notifier_block *nb = nh->head;
+
+	while (nb) {
+
+		ret = nb->notifier_call(nb, val, v);
+		if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
+			break;
+
+		nb = nb->next;
+	}
+
+	return ret;
+}
+
+
+int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
+                                     struct notifier_block *n)
+{
+	return raw_notifier_chain_register((struct raw_notifier_head *)nh, n);
+}
+
+
+int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
+                                 unsigned long val, void *v)
+{
+	return raw_notifier_call_chain((struct raw_notifier_head *)nh, val, v);
+}

repos/dde_linux/src/lib/usb/main.cc

@@ -59,6 +59,14 @@ static void init(Services *services)
 	/* start jiffies */
 	dde_kit_timer_init(0, 0);
 
+	/*
+	 * The RAW driver is initialized first to make sure that it doesn't miss
+	 * notifications about added devices.
+	 */
+	if (services->raw)
+		/* low level interface */
+		module_raw_driver_init();
+
 	/* USB */
 	subsys_usb_init();
 
@@ -82,10 +90,6 @@ static void init(Services *services)
 	/* storage */
 	if (services->stor)
 		module_usb_storage_driver_init();
-
-	if (services->raw)
-		/* low level interface */
-		module_raw_driver_init();
 }
 
 
@@ -103,7 +107,7 @@ void start_usb_driver(Server::Entrypoint &ep)
 	Nic::init(ep);
 
 	if (services.raw)
-		Raw::init(ep);
+		Raw::init(ep, services.raw_report_device_list);
 
 	Routine::add(0, 0, "Main", true);
 	Routine::make_main_current();

repos/dde_linux/src/lib/usb/raw/raw.cc

@@ -13,6 +13,7 @@
 
 #include <base/env.h>
 #include <base/printf.h>
+#include <os/reporter.h>
 #include <root/component.h>
 #include <usb_session/rpc_object.h>
 #include <util/list.h>
@@ -43,13 +44,6 @@ struct Device : List<Device>::Element
 {
 	usb_device *udev;
 
-	Device(usb_device *udev) : udev(udev)
-	{
-		list()->insert(this);
-	}
-
-	~Device() { list()->remove(this); }
-
 	static List<Device> *list()
 	{
 		static List<Device> _l;
@@ -66,6 +60,50 @@ struct Device : List<Device>::Element
 		return nullptr;
 	}
 
+	static Genode::Reporter &device_list_reporter()
+	{
+		static Genode::Reporter _r("devices", 512*1024);
+		return _r;
+	}
+
+	static void report_device_list()
+	{
+		Genode::Reporter::Xml_generator xml(device_list_reporter(), [&] ()
+		{
+
+			for (Device *d = list()->first(); d; d = d->next()) {
+				xml.node("device", [&] ()
+				{
+					char buf[7];
+
+					Genode::snprintf(buf, sizeof(buf), "0x%4x",
+					                 d->udev->descriptor.idVendor);
+					xml.attribute("vendor_id", buf);
+
+					Genode::snprintf(buf, sizeof(buf), "0x%4x",
+					                 d->udev->descriptor.idProduct);
+					xml.attribute("product_id", buf);
+				});
+			}
+		});
+	}
+
+	Device(usb_device *udev) : udev(udev)
+	{
+		list()->insert(this);
+
+		if (device_list_reporter().is_enabled())
+			report_device_list();
+	}
+
+	~Device()
+	{
+		list()->remove(this);
+
+		if (device_list_reporter().is_enabled())
+			report_device_list();
+	}
+
 	usb_interface *interface(unsigned index)
 	{
 		usb_interface *iface = udev->actconfig->interface[index];
@@ -387,9 +425,6 @@ class Usb::Worker
 			_wait_event(_device);
 			_wait_event(_device->udev->actconfig);
 
-			/* set raw driver */
-			_device->udev->dev.driver = &raw_driver.drvwrap.driver;
-
 			if (_sigh_ready.valid())
 				Signal_transmitter(_sigh_ready).submit(1);
 
@@ -510,6 +545,11 @@ class Usb::Session_component : public Session_rpc_object,
 			_tx.sigh_packet_avail(_packet_avail);
 		}
 
+		~Session_component()
+		{
+			_worker.stop();
+		}
+
 		/***********************
 		 ** Session interface **
 		 ***********************/
@@ -677,6 +717,12 @@ class Usb::Root : public Genode::Root_component<Session_component>
 			return session;
 		}
 
+		void _destroy_session(Session_component *session)
+		{
+			::Session::list()->remove(session);
+			Genode::Root_component<Session_component>::_destroy_session(session);
+		}
+
 	public:
 
 		Root(Server::Entrypoint &session_ep,
@@ -686,8 +732,9 @@ class Usb::Root : public Genode::Root_component<Session_component>
 };
 
 
-void Raw::init(Server::Entrypoint &ep)
+void Raw::init(Server::Entrypoint &ep, bool report_device_list)
 {
+	Device::device_list_reporter().enabled(report_device_list);
 	static Usb::Root root(ep, env()->heap());
 	Genode::env()->parent()->announce(ep.rpc_ep().manage(&root));
 }
@@ -697,18 +744,36 @@ void Raw::init(Server::Entrypoint &ep)
  ** C interface **
  *****************/
 
-void raw_register_device(struct usb_device *udev)
+int raw_notify(struct notifier_block *nb, unsigned long action, void *data)
 {
-	::Session::list()->state_change(Usb::Session_component::DEVICE_ADD,
+	struct usb_device *udev = (struct usb_device*)data;
-	                                new (env()->heap()) Device(udev));
+
+	switch (action) {
+
+		case USB_DEVICE_ADD:
+		{
+			::Session::list()->state_change(Usb::Session_component::DEVICE_ADD,
+                                			new (env()->heap()) Device(udev));
+			break;
+		}
+
+		case USB_DEVICE_REMOVE:
+		{
+			Device *dev = Device::device(udev->descriptor.idVendor,
+	                             	 	 udev->descriptor.idProduct);
+			if (dev) {
+				::Session::list()->state_change(Usb::Session_component::DEVICE_REMOVE, dev);
+				destroy(env()->heap(), dev);
+			}
+			break;
+		}
+
+		case USB_BUS_ADD:
+			break;
+
+		case USB_BUS_REMOVE:
+			break;
+    } 
+
+    return NOTIFY_OK;
 }
-
-
-void raw_unregister_device(struct usb_device *udev)
-{
-	Device *dev = Device::device(udev->descriptor.idVendor,
-	                             udev->descriptor.idProduct);
-	if (dev)
-		::Session::list()->state_change(Usb::Session_component::DEVICE_REMOVE, dev);
-}
-

repos/dde_linux/src/lib/usb/raw/raw.h

@@ -7,8 +7,6 @@ struct usb_driver;
 extern struct usb_device_driver raw_driver;
 extern struct usb_driver        raw_intf_driver;
 
-void raw_register_device(struct usb_device *udev);
+int raw_notify(struct notifier_block *nb, unsigned long action, void *data);
-void raw_unregister_device(struct usb_device *udev);
-
 
 #endif /* _RAW_H_ */

repos/dde_linux/src/lib/usb/raw/raw_driver.c

@@ -19,15 +19,12 @@ static int raw_probe(struct usb_device *udev)
 	printk("RAW: vendor: %x product: %x dev %p\n", 
 	       udev->descriptor.idVendor, udev->descriptor.idProduct, udev);
 
-	raw_register_device(udev);
-
 	return -ENODEV;
 }
 
 static void  raw_disconnect(struct usb_device *udev)
 {
 	printk("driver disconnect called\n");
-	raw_unregister_device(udev);
 }
 
 
@@ -67,6 +64,12 @@ struct usb_driver raw_intf_driver =
 };
 
 
+struct notifier_block usb_nb =
+{
+	.notifier_call = raw_notify
+};
+
+
 static int raw_driver_init(void)
 {
 	int err;
@@ -81,6 +84,10 @@ static int raw_driver_init(void)
 
 	printk("RAW: interface driver registered\n");
 
+	usb_register_notify(&usb_nb);
+
+	printk("RAW: notify function registered\n");
+
 	return 0;
 }