random: add a Virtio RNG module

* The default module is replaced by the Virtio RNG module when found.
* This can have the undesired effect of rendering /dev/urandom slow.
* Tested with the following QEmu command line option:
-device virtio-rng-pci,rng=rng0 -object rng-random,filename=/dev/random,id=rng0
* moved random.h to private/drivers headers.

headers/private/drivers/random.h

@@ -23,11 +23,9 @@ typedef struct {
 typedef struct random_module_info {
 	driver_module_info info;
 
-	status_t (*init)();
-	void (*uninit)();
-	status_t (*read)(void *_buffer, size_t *_numBytes);
-	status_t (*write)(const void *_buffer, size_t *_numBytes);
-} random_sim_interface;
+	status_t (*read)(void* cookie, void *_buffer, size_t *_numBytes);
+	status_t (*write)(void* cookie, const void *_buffer, size_t *_numBytes);
+} random_module_info;
 
 
 #endif /* _RANDOM_H */

src/add-ons/kernel/bus_managers/random/Jamfile

@@ -1,5 +1,6 @@
 SubDir HAIKU_TOP src add-ons kernel bus_managers random ;
 
+UsePrivateHeaders drivers ;
 UsePrivateKernelHeaders ;
 
 KernelAddon random :

src/add-ons/kernel/bus_managers/random/driver.cpp

@@ -32,7 +32,8 @@
 
 
 static mutex sRandomLock;
-static random_sim_interface *sRandomModule;
+static random_module_info *sRandomModule;
+static void *sRandomCookie;
 device_manager_info* gDeviceManager;
 
 
@@ -73,7 +74,7 @@ random_read(void *cookie, off_t position, void *_buffer, size_t *_numBytes)
 	TRACE("read(%Ld,, %ld)\n", position, *_numBytes);
 
 	MutexLocker locker(&sRandomLock);
-	return sRandomModule->read(_buffer, _numBytes);
+	return sRandomModule->read(sRandomCookie, _buffer, _numBytes);
 }
 
 
@@ -82,7 +83,11 @@ random_write(void *cookie, off_t position, const void *buffer, size_t *_numBytes
 {
 	TRACE("write(%Ld,, %ld)\n", position, *_numBytes);
 	MutexLocker locker(&sRandomLock);
-	return sRandomModule->write(buffer, _numBytes);
+	if (sRandomModule->write == NULL) {
+		*_numBytes = 0;
+		return EINVAL;
+	}
+	return sRandomModule->write(sRandomCookie, buffer, _numBytes);
 }
 
 
@@ -244,10 +249,8 @@ random_added_device(device_node *node)
 {
 	CALLED();
 
-	void *cookie;
-
 	status_t status = gDeviceManager->get_driver(node,
-		(driver_module_info **)&sRandomModule, &cookie);
+		(driver_module_info **)&sRandomModule, &sRandomCookie);
 
 	return status;
 }

src/add-ons/kernel/bus_managers/random/yarrow_rng.cpp

@@ -290,24 +290,7 @@ kill_chrand(ch_randgen *randgen)
 
 
 static status_t
-yarrow_rng_init()
-{
-	sRandomEnv = new_chrand(8);
-	if (sRandomEnv == NULL)
-		return B_NO_MEMORY;
-	return B_OK;
-}
-
-
-static void
-yarrow_rng_uninit()
-{
-	kill_chrand(sRandomEnv);
-}
-
-
-static status_t
-yarrow_rng_read(void *_buffer, size_t *_numBytes)
+yarrow_rng_read(void* cookie, void *_buffer, size_t *_numBytes)
 {
 	sRandomCount += *_numBytes;
 
@@ -333,7 +316,7 @@ yarrow_rng_read(void *_buffer, size_t *_numBytes)
 
 
 static status_t
-yarrow_rng_write(const void *buffer, size_t *_numBytes)
+yarrow_rng_write(void* cookie, const void *buffer, size_t *_numBytes)
 {
 	OCTET* data = (OCTET*)buffer;
 	for (size_t i = 0; i < *_numBytes / sizeof(OCTET); i++) {
@@ -351,7 +334,10 @@ static status_t
 yarrow_init_bus(device_node* node, void** bus_cookie)
 {
 	CALLED();
-	return yarrow_rng_init();
+	sRandomEnv = new_chrand(8);
+	if (sRandomEnv == NULL)
+		return B_NO_MEMORY;
+	return B_OK;
 }
 
 
@@ -359,7 +345,7 @@ static void
 yarrow_uninit_bus(void* bus_cookie)
 {
 	CALLED();
-	yarrow_rng_uninit();
+	kill_chrand(sRandomEnv);
 }
 
 
@@ -389,8 +375,6 @@ random_module_info gYarrowRandomModule = {
 		NULL,	// rescan
 		yarrow_bus_removed,
 	},
-	yarrow_rng_init,
-	yarrow_rng_uninit,
 	yarrow_rng_read,
 	yarrow_rng_write
 };

src/add-ons/kernel/busses/Jamfile

@@ -8,6 +8,7 @@ if $(HAIKU_ATA_STACK) = 1 {
 }
 
 SubInclude HAIKU_TOP src add-ons kernel busses agp_gart ;
+SubInclude HAIKU_TOP src add-ons kernel busses random ;
 SubInclude HAIKU_TOP src add-ons kernel busses scsi ;
 SubInclude HAIKU_TOP src add-ons kernel busses usb ;
 SubInclude HAIKU_TOP src add-ons kernel busses virtio ;

src/add-ons/kernel/busses/random/Jamfile

@@ -0,0 +1,9 @@
+SubDir HAIKU_TOP src add-ons kernel busses random ;
+
+UsePrivateHeaders drivers virtio ;
+UsePrivateKernelHeaders ;
+
+KernelAddon virtio_rng :
+	virtio_rng.cpp
+	VirtioRNGDevice.cpp
+;

src/add-ons/kernel/busses/random/VirtioRNGDevice.cpp

@@ -0,0 +1,134 @@
+/*
+ * Copyright 2013, Jérôme Duval, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "VirtioRNGPrivate.h"
+
+#include <new>
+#include <stdlib.h>
+#include <string.h>
+
+#include <util/AutoLock.h>
+
+
+const char *
+get_feature_name(uint32 feature)
+{
+	switch (feature) {
+	}
+	return NULL;
+}
+
+
+VirtioRNGDevice::VirtioRNGDevice(device_node *node)
+	:
+	fNode(node),
+	fVirtio(NULL),
+	fVirtioDevice(NULL),
+	fStatus(B_NO_INIT),
+	fOffset(BUFFER_SIZE)
+{
+	CALLED();
+
+	B_INITIALIZE_SPINLOCK(&fInterruptLock);
+	fInterruptCondition.Init(this, "virtio rng transfer");
+
+	get_memory_map(fBuffer, BUFFER_SIZE, &fEntry, 1);
+
+	// get the Virtio device from our parent's parent
+	device_node *parent = gDeviceManager->get_parent_node(node);
+	device_node *virtioParent = gDeviceManager->get_parent_node(parent);
+	gDeviceManager->put_node(parent);
+
+	gDeviceManager->get_driver(virtioParent, (driver_module_info **)&fVirtio,
+		(void **)&fVirtioDevice);
+	gDeviceManager->put_node(virtioParent);
+
+	fVirtio->negociate_features(fVirtioDevice,
+		0, &fFeatures, &get_feature_name);
+
+	fStatus = fVirtio->alloc_queues(fVirtioDevice, 1, &fVirtioQueue);
+	if (fStatus != B_OK) {
+		ERROR("queue allocation failed (%s)\n", strerror(fStatus));
+		return;
+	}
+
+	fStatus = fVirtio->setup_interrupt(fVirtioDevice, NULL, this);
+	if (fStatus != B_OK) {
+		ERROR("interrupt setup failed (%s)\n", strerror(fStatus));
+		return;
+	}
+}
+
+
+VirtioRNGDevice::~VirtioRNGDevice()
+{
+}
+
+
+status_t
+VirtioRNGDevice::InitCheck()
+{
+	return fStatus;
+}
+
+
+status_t
+VirtioRNGDevice::Read(void* _buffer, size_t* _numBytes)
+{
+	CALLED();
+
+	if (fOffset >= BUFFER_SIZE) {
+		{
+			InterruptsSpinLocker locker(fInterruptLock);
+			fExpectsInterrupt = true;
+			fInterruptCondition.Add(&fInterruptConditionEntry);
+		}
+		status_t result = fVirtio->queue_request(fVirtioQueue, NULL, &fEntry,
+			_RequestCallback, this);
+		if (result != B_OK) {
+			ERROR("queueing failed (%s)\n", strerror(result));
+			return result;
+		}
+
+		result = fInterruptConditionEntry.Wait(B_CAN_INTERRUPT);
+
+		{
+			InterruptsSpinLocker locker(fInterruptLock);
+			fExpectsInterrupt = false;
+		}
+
+		if (result == B_OK) {
+			fOffset = 0;
+		} else if (result != B_INTERRUPTED) {
+			ERROR("request failed (%s)\n", strerror(result));
+		}
+	}
+
+	if (fOffset < BUFFER_SIZE) {
+		size_t size = min_c(BUFFER_SIZE - fOffset, *_numBytes);
+		memcpy(_buffer, fBuffer + fOffset, size);
+		fOffset += size;
+		*_numBytes = size;
+	} else
+		*_numBytes = 0;
+	return B_OK;
+}
+
+
+void
+VirtioRNGDevice::_RequestCallback(void* driverCookie, void* cookie)
+{
+	VirtioRNGDevice* device = (VirtioRNGDevice*)driverCookie;
+	device->_RequestInterrupt();
+}
+
+
+void
+VirtioRNGDevice::_RequestInterrupt()
+{
+	SpinLocker locker(fInterruptLock);
+	fInterruptCondition.NotifyAll();
+}

src/add-ons/kernel/busses/random/VirtioRNGPrivate.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2013, Jérôme Duval, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef VIRTIO_RNG_PRIVATE_H
+#define VIRTIO_RNG_PRIVATE_H
+
+
+#include <condition_variable.h>
+#include <lock.h>
+#include "random.h"
+#include <virtio.h>
+
+
+//#define TRACE_VIRTIO_RNG
+#ifdef TRACE_VIRTIO_RNG
+#	define TRACE(x...) dprintf("virtio_rng: " x)
+#else
+#	define TRACE(x...) ;
+#endif
+#define ERROR(x...)			dprintf("\33[33mvirtio_rng:\33[0m " x)
+#define CALLED() 			TRACE("CALLED %s\n", __PRETTY_FUNCTION__)
+
+
+extern device_manager_info* gDeviceManager;
+extern random_for_controller_interface *gRandom;
+
+
+#define BUFFER_SIZE 16
+
+
+class VirtioRNGDevice {
+public:
+								VirtioRNGDevice(device_node* node);
+								~VirtioRNGDevice();
+
+			status_t			InitCheck();
+
+			status_t			Read(void* buffer, size_t* numBytes);
+
+
+private:
+	static	void				_RequestCallback(void* driverCookie,
+									void *cookie);
+			void				_RequestInterrupt();
+
+			device_node*		fNode;
+
+			virtio_device_interface* fVirtio;
+			virtio_device*		fVirtioDevice;
+
+			status_t			fStatus;
+			uint32				fFeatures;
+			::virtio_queue		fVirtioQueue;
+
+			physical_entry 		fEntry;
+			uint8				fBuffer[BUFFER_SIZE];
+			uint32				fOffset;
+
+			spinlock			fInterruptLock;
+			ConditionVariable	fInterruptCondition;
+			ConditionVariableEntry fInterruptConditionEntry;
+			bool				fExpectsInterrupt;
+};
+
+
+#endif // VIRTIO_RNG_PRIVATE_H

src/add-ons/kernel/busses/random/virtio_rng.cpp

@@ -0,0 +1,197 @@
+/*
+ * Copyright 2013, Jérôme Duval, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "VirtioRNGPrivate.h"
+
+#include <new>
+#include <stdlib.h>
+#include <string.h>
+
+
+#define VIRTIO_RNG_CONTROLLER_PRETTY_NAME "Virtio RNG Device"
+
+#define VIRTIO_RNG_DRIVER_MODULE_NAME "busses/random/virtio_rng/driver_v1"
+#define VIRTIO_RNG_DEVICE_MODULE_NAME "busses/random/virtio_rng/device_v1"
+
+
+device_manager_info *gDeviceManager;
+random_for_controller_interface *gRandom;
+
+
+//	#pragma mark - Random module interface
+
+
+static status_t
+sim_init_bus(device_node *node, void **_cookie)
+{
+	CALLED();
+
+	VirtioRNGDevice *device =  new(std::nothrow)
+		VirtioRNGDevice(node);
+	if (device == NULL)
+		return B_NO_MEMORY;
+	status_t status = device->InitCheck();
+	if (status < B_OK) {
+		delete device;
+		return status;
+	}
+
+	*_cookie = device;
+	return B_OK;
+}
+
+
+static void
+sim_uninit_bus(void *cookie)
+{
+	CALLED();
+	VirtioRNGDevice *device = (VirtioRNGDevice*)cookie;
+
+	delete device;
+}
+
+
+static status_t
+sim_read(void* cookie, void *_buffer, size_t *_numBytes)
+{
+	VirtioRNGDevice *device = (VirtioRNGDevice*)cookie;
+	return device->Read(_buffer, _numBytes);
+}
+
+
+//	#pragma mark -	Driver module interface
+
+
+static float
+virtio_rng_supports_device(device_node *parent)
+{
+	const char *bus;
+	uint16 deviceType;
+
+	// make sure parent is really the Virtio bus manager
+	if (gDeviceManager->get_attr_string(parent, B_DEVICE_BUS, &bus, false))
+		return -1;
+
+	if (strcmp(bus, "virtio"))
+		return 0.0;
+
+	// check whether it's really a Virtio Entropy Device
+	if (gDeviceManager->get_attr_uint16(parent, VIRTIO_DEVICE_TYPE_ITEM,
+			&deviceType, true) != B_OK || deviceType != VIRTIO_DEVICE_ID_ENTROPY)
+		return 0.0;
+
+	TRACE("Virtio RNG device found!\n");
+
+	return 0.6f;
+}
+
+
+static status_t
+virtio_rng_register_device(device_node *parent)
+{
+	CALLED();
+
+	device_attr attrs[] = {
+		{ NULL }
+	};
+
+	return gDeviceManager->register_node(parent, VIRTIO_RNG_DRIVER_MODULE_NAME,
+		attrs, NULL, NULL);
+}
+
+
+static status_t
+virtio_rng_init_driver(device_node *node, void **_cookie)
+{
+	CALLED();
+	*_cookie = node;
+	return B_OK;
+}
+
+
+static status_t
+virtio_rng_register_child_devices(void *cookie)
+{
+	CALLED();
+	device_node *node = (device_node *)cookie;
+
+	device_attr attrs[] = {
+		{ B_DEVICE_FIXED_CHILD, B_STRING_TYPE,
+			{ string: RANDOM_FOR_CONTROLLER_MODULE_NAME }},
+		{ B_DEVICE_PRETTY_NAME, B_STRING_TYPE,
+			{ string: VIRTIO_RNG_CONTROLLER_PRETTY_NAME }},
+		{ NULL }
+	};
+
+	return gDeviceManager->register_node(node,
+		VIRTIO_RNG_DEVICE_MODULE_NAME, attrs, NULL, NULL);
+}
+
+
+static status_t
+std_ops(int32 op, ...)
+{
+	switch (op) {
+		case B_MODULE_INIT:
+		case B_MODULE_UNINIT:
+			return B_OK;
+
+		default:
+			return B_ERROR;
+	}
+}
+
+
+static random_module_info sVirtioRNGDeviceInterface = {
+	{
+		{
+			VIRTIO_RNG_DEVICE_MODULE_NAME,
+			0,
+			std_ops
+		},
+		NULL,	// supported devices
+		NULL,	// register node
+		sim_init_bus,
+		sim_uninit_bus,
+		NULL,	// register child devices
+		NULL,	// rescan
+		NULL	// bus_removed
+	},
+
+	sim_read,
+	NULL	// write
+
+};
+
+
+static driver_module_info sVirtioRNGDriver = {
+	{
+		VIRTIO_RNG_DRIVER_MODULE_NAME,
+		0,
+		std_ops
+	},
+	virtio_rng_supports_device,
+	virtio_rng_register_device,
+	virtio_rng_init_driver,
+	NULL,	// uninit_driver,
+	virtio_rng_register_child_devices,
+	NULL,	// rescan
+	NULL,	// device_removed
+};
+
+
+module_dependency module_dependencies[] = {
+	{ B_DEVICE_MANAGER_MODULE_NAME, (module_info **)&gDeviceManager },
+	{ RANDOM_FOR_CONTROLLER_MODULE_NAME, (module_info **)&gRandom },
+	{}
+};
+
+
+module_info *modules[] = {
+	(module_info *)&sVirtioRNGDriver,
+	(module_info *)&sVirtioRNGDeviceInterface,
+	NULL
+};