random: always use the PRNG, and use entropy sources to feed it

remove the yarrow module. the hardware modules can push entropy with queue_randomness().
virtio_rng will now push entropy every 300 seconds.
helps with #14937

Change-Id: If76c5deabf61dc616a0e051332f44b89deb6b8a1
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5824
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

headers/private/drivers/random.h

@@ -14,18 +14,12 @@
 
 typedef struct {
 	driver_module_info info;
+
+	status_t (*queue_randomness)(uint64 value);
 } random_for_controller_interface;
 
 
 #define RANDOM_FOR_CONTROLLER_MODULE_NAME "bus_managers/random/controller/driver_v1"
 
-// Bus manager interface used by Random controller drivers.
-typedef struct random_module_info {
-	driver_module_info info;
-
-	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/driver.cpp

@@ -34,7 +34,6 @@
 
 
 static mutex sRandomLock;
-static random_module_info *sRandomModule;
 static void *sRandomCookie;
 device_manager_info* gDeviceManager;
 
@@ -44,6 +43,15 @@ typedef struct {
 } random_driver_info;
 
 
+static status_t
+random_queue_randomness(uint64 value)
+{
+	MutexLocker locker(&sRandomLock);
+	RANDOM_ENQUEUE(value);
+	return B_OK;
+}
+
+
 //	#pragma mark - device module API
 
 
@@ -74,7 +82,7 @@ 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(sRandomCookie, _buffer, _numBytes);
+	return RANDOM_READ(sRandomCookie, _buffer, _numBytes);
 }
 
 
@@ -83,11 +91,7 @@ random_write(void *cookie, off_t position, const void *buffer, size_t *_numBytes
 {
 	TRACE("write(%Ld,, %ld)\n", position, *_numBytes);
 	MutexLocker locker(&sRandomLock);
-	if (sRandomModule->write == NULL) {
-		*_numBytes = 0;
-		return EINVAL;
-	}
-	return sRandomModule->write(sRandomCookie, buffer, _numBytes);
+	return RANDOM_WRITE(sRandomCookie, buffer, _numBytes);
 }
 
 
@@ -187,6 +191,7 @@ random_init_driver(device_node *node, void **cookie)
 		return B_NO_MEMORY;
 
 	mutex_init(&sRandomLock, "/dev/random lock");
+	RANDOM_INIT();
 
 	memset(info, 0, sizeof(*info));
 
@@ -202,6 +207,8 @@ random_uninit_driver(void *_cookie)
 {
 	CALLED();
 
+	RANDOM_UNINIT();
+
 	mutex_destroy(&sRandomLock);
 
 	random_driver_info* info = (random_driver_info*)_cookie;
@@ -220,38 +227,10 @@ random_register_child_devices(void* _cookie)
 		gDeviceManager->publish_device(info->node, "urandom",
 			RANDOM_DEVICE_MODULE_NAME);
 	}
-
-	// add the default Yarrow RNG
-	device_attr attrs[] = {
-		{ B_DEVICE_PRETTY_NAME, B_STRING_TYPE,
-			{ string: "Yarrow RNG" }},
-		{ B_DEVICE_FIXED_CHILD, B_STRING_TYPE,
-			{ string: RANDOM_FOR_CONTROLLER_MODULE_NAME }},
-		{ NULL }
-	};
-
-	device_node* node;
-	return gDeviceManager->register_node(info->node,
-		YARROW_RNG_SIM_MODULE_NAME, attrs, NULL, &node);
-}
-
-
-//	#pragma mark -
-
-
-status_t
-random_added_device(device_node *node)
-{
-	CALLED();
-
-	status_t status = gDeviceManager->get_driver(node,
-		(driver_module_info **)&sRandomModule, &sRandomCookie);
-
 	return status;
 }
 
 
-
 //	#pragma mark -
 
 
@@ -311,11 +290,13 @@ random_for_controller_interface sRandomForControllerModule = {
 		},
 
 		NULL, // supported devices
-		random_added_device,
+		NULL,
 		NULL,
 		NULL,
 		NULL
-	}
+	},
+
+	random_queue_randomness,
 };
 
 
@@ -323,6 +304,5 @@ module_info* modules[] = {
 	(module_info*)&sRandomDriver,
 	(module_info*)&sRandomDevice,
 	(module_info*)&sRandomForControllerModule,
-	(module_info*)&gYarrowRandomModule,
 	NULL
 };

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

@@ -286,10 +286,28 @@ kill_chrand(ch_randgen *randgen)
 
 
 //	#pragma mark -
-//	Random interface
 
 
-static status_t
+status_t
+yarrow_init()
+{
+	CALLED();
+	sRandomEnv = new_chrand(8);
+	if (sRandomEnv == NULL)
+		return B_NO_MEMORY;
+	return B_OK;
+}
+
+
+void
+yarrow_uninit()
+{
+	CALLED();
+	kill_chrand(sRandomEnv);
+}
+
+
+status_t
 yarrow_rng_read(void* cookie, void *_buffer, size_t *_numBytes)
 {
 	if (!IS_USER_ADDRESS(_buffer))
@@ -323,7 +341,7 @@ yarrow_rng_read(void* cookie, void *_buffer, size_t *_numBytes)
 }
 
 
-static status_t
+status_t
 yarrow_rng_write(void* cookie, const void *_buffer, size_t *_numBytes)
 {
 	OCTET *buffer = (OCTET*)_buffer;
@@ -342,54 +360,9 @@ yarrow_rng_write(void* cookie, const void *_buffer, size_t *_numBytes)
 }
 
 
-//	#pragma mark -
-
-
-static status_t
-yarrow_init_bus(device_node* node, void** bus_cookie)
+void
+yarrow_enqueue_randomness(const uint64 value)
 {
 	CALLED();
-	sRandomEnv = new_chrand(8);
-	if (sRandomEnv == NULL)
-		return B_NO_MEMORY;
-	return B_OK;
+	chseed(sRandomEnv, value);
 }
-
-
-static void
-yarrow_uninit_bus(void* bus_cookie)
-{
-	CALLED();
-	kill_chrand(sRandomEnv);
-}
-
-
-static void
-yarrow_bus_removed(void* bus_cookie)
-{
-	return;
-}
-
-
-//	#pragma mark -
-
-
-random_module_info gYarrowRandomModule = {
-	{
-		{
-			YARROW_RNG_SIM_MODULE_NAME,
-			0,
-			NULL
-		},
-
-		NULL, // supports_device,
-		NULL, // register_device,
-		yarrow_init_bus,
-		yarrow_uninit_bus,
-		NULL,	// register child devices
-		NULL,	// rescan
-		yarrow_bus_removed,
-	},
-	yarrow_rng_read,
-	yarrow_rng_write
-};

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

@@ -14,15 +14,23 @@
 #include "random.h"
 
 
-#define YARROW_RNG_SIM_MODULE_NAME "bus_managers/random/yarrow_rng/device/v1"
-
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+status_t yarrow_init();
+void yarrow_uninit();
+void yarrow_enqueue_randomness(const uint64 value);
 
-extern random_module_info gYarrowRandomModule;
+status_t yarrow_rng_read(void* cookie, void *_buffer, size_t *_numBytes);
+status_t yarrow_rng_write(void* cookie, const void *_buffer, size_t *_numBytes);
+
+
+#define RANDOM_INIT yarrow_init
+#define RANDOM_UNINIT yarrow_uninit
+#define RANDOM_ENQUEUE yarrow_enqueue_randomness
+#define RANDOM_READ yarrow_rng_read
+#define RANDOM_WRITE yarrow_rng_write
 
 
 #ifdef __cplusplus

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

@@ -24,24 +24,19 @@ get_feature_name(uint32 feature)
 
 VirtioRNGDevice::VirtioRNGDevice(device_node *node)
 	:
-	fNode(node),
 	fVirtio(NULL),
 	fVirtioDevice(NULL),
 	fStatus(B_NO_INIT),
-	fOffset(BUFFER_SIZE),
-	fExpectsInterrupt(false)
+	fExpectsInterrupt(false),
+	fDPCHandle(NULL)
 {
 	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);
+	device_node *virtioParent = gDeviceManager->get_parent_node(node);
 
 	gDeviceManager->get_driver(virtioParent, (driver_module_info **)&fVirtio,
 		(void **)&fVirtioDevice);
@@ -68,11 +63,31 @@ VirtioRNGDevice::VirtioRNGDevice(device_node *node)
 		ERROR("queue interrupt setup failed (%s)\n", strerror(fStatus));
 		return;
 	}
+
+	fStatus = gDPC->new_dpc_queue(&fDPCHandle, "virtio_rng timer",
+		B_LOW_PRIORITY);
+	if (fStatus != B_OK) {
+		ERROR("dpc setup failed (%s)\n", strerror(fStatus));
+		return;
+	}
+
+	if (fStatus == B_OK) {
+		fTimer.user_data = this;
+		fStatus = add_timer(&fTimer, &HandleTimerHook, 300 * 1000 * 1000, B_PERIODIC_TIMER);
+		if (fStatus != B_OK)
+			ERROR("timer setup failed (%s)\n", strerror(fStatus));
+	}
+
+	// trigger also now
+	gDPC->queue_dpc(fDPCHandle, HandleDPC, this);
 }
 
 
 VirtioRNGDevice::~VirtioRNGDevice()
 {
+	cancel_timer(&fTimer);
+	gDPC->delete_dpc_queue(fDPCHandle);
+
 }
 
 
@@ -84,46 +99,42 @@ VirtioRNGDevice::InitCheck()
 
 
 status_t
-VirtioRNGDevice::Read(void* _buffer, size_t* _numBytes)
+VirtioRNGDevice::_Enqueue()
 {
 	CALLED();
 
-	if (fOffset >= BUFFER_SIZE) {
-		{
-			InterruptsSpinLocker locker(fInterruptLock);
-			fExpectsInterrupt = true;
-			fInterruptCondition.Add(&fInterruptConditionEntry);
-		}
-		status_t result = fVirtio->queue_request(fVirtioQueue, NULL, &fEntry,
-			NULL);
-		if (result != B_OK) {
-			ERROR("queueing failed (%s)\n", strerror(result));
-			return result;
-		}
+	uint64 value = 0;
+	physical_entry entry;
+	get_memory_map(&value, sizeof(value), &entry, 1);
 
-		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));
-		}
+	{
+		InterruptsSpinLocker locker(fInterruptLock);
+		fExpectsInterrupt = true;
+		fInterruptCondition.Add(&fInterruptConditionEntry);
+	}
+	status_t result = fVirtio->queue_request(fVirtioQueue, NULL, &entry, NULL);
+	if (result != B_OK) {
+		ERROR("queueing failed (%s)\n", strerror(result));
+		return result;
 	}
 
-	if (fOffset < BUFFER_SIZE) {
-		size_t size = min_c(BUFFER_SIZE - fOffset, *_numBytes);
-		if (user_memcpy(_buffer, fBuffer + fOffset, size) != B_OK)
-			return B_BAD_ADDRESS;
-		fOffset += size;
-		*_numBytes = size;
-	} else
-		*_numBytes = 0;
-	return B_OK;
+	result = fInterruptConditionEntry.Wait(B_CAN_INTERRUPT);
+
+	{
+		InterruptsSpinLocker locker(fInterruptLock);
+		fExpectsInterrupt = false;
+	}
+
+	if (result == B_OK) {
+		if (value != 0) {
+			gRandom->queue_randomness(value);
+			TRACE("enqueue %" B_PRIx64 "\n", value);
+		}
+	} else if (result != B_OK && result != B_INTERRUPTED) {
+		ERROR("request failed (%s)\n", strerror(result));
+	}
+
+	return result;
 }
 
 
@@ -145,3 +156,22 @@ VirtioRNGDevice::_RequestInterrupt()
 	SpinLocker locker(fInterruptLock);
 	fInterruptCondition.NotifyAll();
 }
+
+
+/*static*/ int32
+VirtioRNGDevice::HandleTimerHook(struct timer* timer)
+{
+	VirtioRNGDevice* device = reinterpret_cast<VirtioRNGDevice*>(timer->user_data);
+
+	gDPC->queue_dpc(device->fDPCHandle, HandleDPC, device);
+	return B_HANDLED_INTERRUPT;
+}
+
+
+/*static*/ void
+VirtioRNGDevice::HandleDPC(void *arg)
+{
+	VirtioRNGDevice* device = reinterpret_cast<VirtioRNGDevice*>(arg);
+	device->_Enqueue();
+}
+

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

@@ -7,6 +7,7 @@
 
 
 #include <condition_variable.h>
+#include <dpc.h>
 #include <lock.h>
 #include "random.h"
 #include <virtio.h>
@@ -24,9 +25,7 @@
 
 extern device_manager_info* gDeviceManager;
 extern random_for_controller_interface *gRandom;
-
-
-#define BUFFER_SIZE 16
+extern dpc_module_info *gDPC;
 
 
 class VirtioRNGDevice {
@@ -36,15 +35,15 @@ public:
 
 			status_t			InitCheck();
 
-			status_t			Read(void* buffer, size_t* numBytes);
-
+protected:
+	static	int32				HandleTimerHook(struct timer* timer);
+	static	void				HandleDPC(void* arg);
 
 private:
 	static	void				_RequestCallback(void* driverCookie,
 									void *cookie);
 			void				_RequestInterrupt();
-
-			device_node*		fNode;
+			status_t			_Enqueue();
 
 			virtio_device_interface* fVirtio;
 			virtio_device*		fVirtioDevice;
@@ -53,14 +52,13 @@ private:
 			uint32				fFeatures;
 			::virtio_queue		fVirtioQueue;
 
-			physical_entry 		fEntry;
-			uint8				fBuffer[BUFFER_SIZE];
-			uint32				fOffset;
-
 			spinlock			fInterruptLock;
 			ConditionVariable	fInterruptCondition;
 			ConditionVariableEntry fInterruptConditionEntry;
 			bool				fExpectsInterrupt;
+
+			timer				fTimer;
+			void*				fDPCHandle;
 };
 
 

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

@@ -19,47 +19,7 @@
 
 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);
-}
+dpc_module_info *gDPC;
 
 
 //	#pragma mark -	Driver module interface
@@ -107,77 +67,39 @@ static status_t
 virtio_rng_init_driver(device_node *node, void **_cookie)
 {
 	CALLED();
-	*_cookie = node;
+	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 status_t
-virtio_rng_register_child_devices(void *cookie)
+static void
+virtio_rng_uninit_driver(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);
+	VirtioRNGDevice *device = (VirtioRNGDevice*)cookie;
+	delete device;
 }
 
 
-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
+		NULL
 	},
 	virtio_rng_supports_device,
 	virtio_rng_register_device,
 	virtio_rng_init_driver,
-	NULL,	// uninit_driver,
-	virtio_rng_register_child_devices,
+	virtio_rng_uninit_driver,
+	NULL,
 	NULL,	// rescan
 	NULL,	// device_removed
 };
@@ -186,12 +108,12 @@ static driver_module_info sVirtioRNGDriver = {
 module_dependency module_dependencies[] = {
 	{ B_DEVICE_MANAGER_MODULE_NAME, (module_info **)&gDeviceManager },
 	{ RANDOM_FOR_CONTROLLER_MODULE_NAME, (module_info **)&gRandom },
+	{ B_DPC_MODULE_NAME, (module_info **)&gDPC },
 	{}
 };
 
 
 module_info *modules[] = {
 	(module_info *)&sVirtioRNGDriver,
-	(module_info *)&sVirtioRNGDeviceInterface,
 	NULL
 };

src/system/kernel/device_manager/device_manager.cpp

@@ -1743,6 +1743,7 @@ device_node::_GetNextDriverPath(void*& cookie, KPath& _path)
 					_AddPath(*stack, "bus_managers");
 				} else if (!generic) {
 					_AddPath(*stack, "drivers");
+					_AddPath(*stack, "busses/virtio");
 				} else {
 					// For generic drivers, we only allow busses when the
 					// request is more specified
@@ -1756,7 +1757,6 @@ device_node::_GetNextDriverPath(void*& cookie, KPath& _path)
 					_AddPath(*stack, "busses/i2c");
 					_AddPath(*stack, "busses/scsi");
 					_AddPath(*stack, "busses/random");
-					_AddPath(*stack, "busses/virtio");
 					_AddPath(*stack, "bus_managers/pci");
 				}
 				break;