loop: no longer requires a reader thread, it delivers directly to the device's receive queue

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21215 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/net/net_stack.h

@@ -101,6 +101,9 @@ struct net_stack_module_info {
 	status_t (*device_link_changed)(struct net_device *device);
 	status_t (*device_removed)(struct net_device *device);
 
+	status_t (*device_enqueue_buffer)(struct net_device *device,
+				struct net_buffer *buffer);
+
 	// Utility Functions
 
 	// notification

src/add-ons/kernel/network/devices/loopback/loopback.cpp

@@ -22,7 +22,6 @@
 
 
 struct loopback_device : net_device {
-	net_fifo	fifo;
 };
 
 
@@ -30,34 +29,6 @@ struct net_buffer_module_info *gBufferModule;
 static struct net_stack_module_info *sStackModule;
 
 
-/*!
-	Swaps \a size bytes of the memory pointed to by \a and \b with each other.
-*/
-void
-swap_memory(void *a, void *b, size_t size)
-{
-	uint32 *a4 = (uint32 *)a;
-	uint32 *b4 = (uint32 *)b;
-	while (size > 4) {
-		uint32 temp = *a4;
-		*(a4++) = *b4;
-		*(b4++) = temp;
-
-		size -= 4;
-	}
-
-	uint8 *a1 = (uint8 *)a4;
-	uint8 *b1 = (uint8 *)b4;
-	while (size > 0) {
-		uint8 temp = *a1;
-		*(a1++) = *b1;
-		*(b1++) = temp;
-
-		size--;
-	}
-}
-
-
 //	#pragma mark -
 
 
@@ -116,18 +87,15 @@ loopback_uninit(net_device *_device)
 
 
 status_t
-loopback_up(net_device *_device)
+loopback_up(net_device *device)
 {
-	loopback_device *device = (loopback_device *)_device;
-	return sStackModule->init_fifo(&device->fifo, "loopback fifo", 65536);
+	return B_OK;
 }
 
 
 void
-loopback_down(net_device *_device)
+loopback_down(net_device *device)
 {
-	loopback_device *device = (loopback_device *)_device;
-	sStackModule->uninit_fifo(&device->fifo);
 }
 
 
@@ -140,36 +108,18 @@ loopback_control(net_device *device, int32 op, void *argument,
 
 
 status_t
-loopback_send_data(net_device *_device, net_buffer *buffer)
+loopback_send_data(net_device *device, net_buffer *buffer)
 {
-	loopback_device *device = (loopback_device *)_device;
-	return sStackModule->fifo_enqueue_buffer(&device->fifo, buffer);
-}
-
-
-status_t
-loopback_receive_data(net_device *_device, net_buffer **_buffer)
-{
-	loopback_device *device = (loopback_device *)_device;
-	net_buffer *buffer;
-
-	status_t status = sStackModule->fifo_dequeue_buffer(&device->fifo, 0, 0, &buffer);
-	if (status < B_OK)
-		return status;
-
-	// swap network addresses before delivering
 	gBufferModule->swap_addresses(buffer);
 
-	*_buffer = buffer;
-	return B_OK;
+	return sStackModule->device_enqueue_buffer(device, buffer);
 }
 
 
 status_t
 loopback_set_mtu(net_device *device, size_t mtu)
 {
-	if (mtu > 65536
-		|| mtu < 16)
+	if (mtu > 65536 || mtu < 16)
 		return B_BAD_VALUE;
 
 	device->mtu = mtu;
@@ -231,7 +181,7 @@ net_device_module_info sLoopbackModule = {
 	loopback_down,
 	loopback_control,
 	loopback_send_data,
-	loopback_receive_data,
+	NULL, // receive_data
 	loopback_set_mtu,
 	loopback_set_promiscuous,
 	loopback_set_media,

src/add-ons/kernel/network/stack/datalink.cpp

@@ -555,17 +555,22 @@ interface_protocol_up(net_datalink_protocol *_protocol)
 	if (status < B_OK)
 		return status;
 
-	// give the thread a nice name
-	char name[B_OS_NAME_LENGTH];
-	snprintf(name, sizeof(name), "%s reader", device->name);
+	if (device->module->receive_data != NULL) {
+		// give the thread a nice name
+		char name[B_OS_NAME_LENGTH];
+		snprintf(name, sizeof(name), "%s reader", device->name);
 
-	deviceInterface->reader_thread = spawn_kernel_thread(device_reader_thread, name,
-		B_REAL_TIME_DISPLAY_PRIORITY - 10, deviceInterface);
-	if (deviceInterface->reader_thread < B_OK)
-		return deviceInterface->reader_thread;
+		deviceInterface->reader_thread =
+			spawn_kernel_thread(device_reader_thread, name,
+				B_REAL_TIME_DISPLAY_PRIORITY - 10, deviceInterface);
+		if (deviceInterface->reader_thread < B_OK)
+			return deviceInterface->reader_thread;
+	}
 
 	device->flags |= IFF_UP;
-	resume_thread(deviceInterface->reader_thread);
+
+	if (device->module->receive_data != NULL)
+		resume_thread(deviceInterface->reader_thread);
 
 	deviceInterface->up_count = 1;
 	return B_OK;

src/add-ons/kernel/network/stack/interfaces.cpp

@@ -551,19 +551,22 @@ down_device_interface(net_device_interface *interface)
 
 	notify_device_monitors(interface, B_DEVICE_GOING_DOWN);
 
-	thread_id reader_thread = interface->reader_thread;
+	if (device->module->receive_data != NULL) {
+		thread_id reader_thread = interface->reader_thread;
 
-	// TODO when setting the interface down, should we clear the receive queue?
+		// TODO when setting the interface down,
+		//      should we clear the receive queue?
 
-	// one of the callers must hold a reference to the net_device_interface
-	// usually it is one of the net_interfaces.
-	recursive_lock_unlock(&interface->rx_lock);
+		// one of the callers must hold a reference to the net_device_interface
+		// usually it is one of the net_interfaces.
+		recursive_lock_unlock(&interface->rx_lock);
 
-	// make sure the reader thread is gone before shutting down the interface
-	status_t status;
-	wait_for_thread(reader_thread, &status);
+		// make sure the reader thread is gone before shutting down the interface
+		status_t status;
+		wait_for_thread(reader_thread, &status);
 
-	recursive_lock_lock(&interface->rx_lock);
+		recursive_lock_lock(&interface->rx_lock);
+	}
 }
 
 
@@ -804,6 +807,21 @@ device_removed(net_device *device)
 }
 
 
+status_t
+device_enqueue_buffer(net_device *device, net_buffer *buffer)
+{
+	net_device_interface *interface = get_device_interface(device->index);
+
+	if (interface == NULL)
+		return ENODEV;
+
+	status_t status = fifo_enqueue_buffer(&interface->receive_queue, buffer);
+
+	put_device_interface(interface);
+	return status;
+}
+
+
 //	#pragma mark -
 
 

src/add-ons/kernel/network/stack/interfaces.h

@@ -97,5 +97,6 @@ status_t unregister_device_monitor(struct net_device *device,
 	struct net_device_monitor *monitor);
 status_t device_link_changed(net_device *device);
 status_t device_removed(net_device *device);
+status_t device_enqueue_buffer(net_device *device, net_buffer *buffer);
 
 #endif	// INTERFACES_H

src/add-ons/kernel/network/stack/stack.cpp

@@ -923,6 +923,7 @@ net_stack_module_info gNetStackModule = {
 	unregister_device_monitor,
 	device_link_changed,
 	device_removed,
+	device_enqueue_buffer,
 
 	notify_socket,