loopback_frame: apply an ethernet header for packet capture

* the packet capture expects frames, so loopback_frame should actually apply framing and deframing
for loopback packets.
* datalink: set the address for host routes
* device_interfaces: call the deframing if any in device_enqueue_buffer()
tested with ping 127.0.0.1 and ping6 ::1, while removing the local flag on both routes.

Change-Id: I2085735bdac3bb85908189a2e1acb2540818c7bd
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6451
Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

src/add-ons/kernel/network/datalink_protocols/loopback_frame/loopback_frame.cpp

@@ -35,6 +35,10 @@ status_t
 loopback_deframe(net_device* device, net_buffer* buffer)
 {
 	// there is not that much to do...
+	NetBufferHeaderRemover<ether_header> bufferHeader(buffer);
+	if (bufferHeader.Status() != B_OK)
+		return bufferHeader.Status();
+
 	return B_OK;
 }
 
@@ -102,6 +106,28 @@ loopback_frame_uninit(net_datalink_protocol* protocol)
 status_t
 loopback_frame_send_data(net_datalink_protocol* protocol, net_buffer* buffer)
 {
+	NetBufferPrepend<ether_header> bufferHeader(buffer);
+	if (bufferHeader.Status() != B_OK)
+		return bufferHeader.Status();
+
+	ether_header &header = bufferHeader.Data();
+
+	switch (buffer->interface_address->domain->family) {
+		case AF_INET:
+			header.type = B_HOST_TO_BENDIAN_INT16(ETHER_TYPE_IP);
+			break;
+		case AF_INET6:
+			header.type = B_HOST_TO_BENDIAN_INT16(ETHER_TYPE_IPV6);
+			break;
+		default:
+			header.type = 0;
+			break;
+	}
+
+	memset(header.source, 0, ETHER_ADDRESS_LENGTH);
+	memset(header.destination, 0, ETHER_ADDRESS_LENGTH);
+	bufferHeader.Sync();
+
 	return protocol->next->module->send_data(protocol->next, buffer);
 }
 

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

@@ -360,6 +360,14 @@ datalink_send_routed_data(struct net_route* route, net_buffer* buffer)
 		return ENETUNREACH;
 	}
 
+	if ((route->flags & RTF_HOST) != 0) {
+		TRACE("  host route\n");
+		// We set the interface address here, so the buffer is delivered
+		// directly to the domain in interfaces.cpp:device_consumer_thread()
+		address->AcquireReference();
+		set_interface_address(buffer->interface_address, address);
+	}
+
 	if ((route->flags & RTF_LOCAL) != 0) {
 		TRACE("  local route\n");
 

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

@@ -821,7 +821,13 @@ device_enqueue_buffer(net_device* device, net_buffer* buffer)
 	if (interface == NULL)
 		return B_DEVICE_NOT_FOUND;
 
-	status_t status = fifo_enqueue_buffer(&interface->receive_queue, buffer);
+	status_t status = interface->deframe_func(interface->device, buffer);
+	if (status != B_OK) {
+		gNetBufferModule.free(buffer);
+		return status;
+	}
+
+	status = fifo_enqueue_buffer(&interface->receive_queue, buffer);
 
 	put_device_interface(interface);
 	return status;