Fix 0 byte string sending and check for lengths

Embed vendor information into build parameters & defines so SlimeVR vendors can maintain their own firmware updates without adding new boards

Bump protocol version to 21

platformio-tools.ini

@@ -20,6 +20,11 @@ board = esp12e
 build_flags =
   ${env.build_flags}
   -D BOARD=BOARD_SLIMEVR
+  -D VENDOR_NAME='"SlimeVR"'
+  -D VENDOR_URL='"https://slimevr.dev"'
+  -D PRODUCT_NAME='"SlimeVR Tracker"'
+  -D UPDATE_ADDRESS='"SlimeVR/SlimeVR-Tracker-ESP"'
+  -D UPDATE_NAME='"BOARD_SLIMEVR-firmware"'
 
 [env:BOARD_SLIMEVR_V1_2]
 platform = espressif8266 @ 4.2.1
@@ -27,6 +32,11 @@ board = esp12e
 build_flags =
   ${env.build_flags}
   -D BOARD=BOARD_SLIMEVR_V1_2
+  -D VENDOR_NAME='"SlimeVR"'
+  -D VENDOR_URL='"https://slimevr.dev"'
+  -D PRODUCT_NAME='"SlimeVR Tracker v1.2"'
+  -D UPDATE_ADDRESS='"SlimeVR/SlimeVR-Tracker-ESP"'
+  -D UPDATE_NAME='"BOARD_SLIMEVR_V1_2-firmware"'
 
 [env:BOARD_SLIMEVR_DEV]
 platform = espressif8266 @ 4.2.1
@@ -34,6 +44,8 @@ board = esp12e
 build_flags =
   ${env.build_flags}
   -D BOARD=BOARD_SLIMEVR_DEV
+  -D VENDOR_NAME='"SlimeVR"'
+  -D PRODUCT_NAME='"SlimeVR Tracker (dev)"'
 
 [env:BOARD_GLOVE_IMU_SLIMEVR_DEV]
 platform = espressif32 @ 6.7.0
@@ -44,6 +56,7 @@ build_flags =
   ${env.build_flags}
   -DESP32C3
   -D BOARD=BOARD_GLOVE_IMU_SLIMEVR_DEV
+  -D PRODUCT_NAME='"SlimeVR Glove (dev)"'
 board = lolin_c3_mini
 
 [env:BOARD_NODEMCU]

platformio.ini

@@ -68,6 +68,14 @@ board = esp12e
 ; Comment out this line below if you have any trouble uploading the firmware
 ; and if it has a CP2102 on it (a square chip next to the usb port): change to 3000000 (3 million) for even faster upload speed
 upload_speed = 921600
+build_flags =
+  ${env.build_flags}
+  -D BOARD=BOARD_SLIMEVR_V1_2
+  -D VENDOR_NAME='"SlimeVR"'
+  -D VENDOR_URL='"https://slimevr.dev"'
+  -D PRODUCT_NAME='"SlimeVR Tracker v1.2"'
+  -D UPDATE_ADDRESS='"SlimeVR/SlimeVR-Tracker-ESP"'
+  -D UPDATE_NAME='"BOARD_SLIMEVR_V1_2-firmware"'
 
 ; Uncomment below if you want to build for ESP-01
 ;[env:esp01_1m]

src/debug.h

@@ -94,7 +94,7 @@
 // Not recommended for production
 #define ENABLE_INSPECTION false
 
-#define PROTOCOL_VERSION 20
+#define PROTOCOL_VERSION 21
 
 #ifndef FIRMWARE_VERSION
 #define FIRMWARE_VERSION "UNKNOWN"

src/globals.h

@@ -52,3 +52,23 @@
 #ifndef EXPERIMENTAL_BNO_DISABLE_ACCEL_CALIBRATION
 #define EXPERIMENTAL_BNO_DISABLE_ACCEL_CALIBRATION true
 #endif
+
+#ifndef VENDOR_NAME
+#define VENDOR_NAME "Unknown"
+#endif
+
+#ifndef VENDOR_URL
+#define VENDOR_URL ""
+#endif
+
+#ifndef PRODUCT_NAME
+#define PRODUCT_NAME "SlimeVR Tracker"
+#endif
+
+#ifndef UPDATE_ADDRESS
+#define UPDATE_ADDRESS ""
+#endif
+
+#ifndef UPDATE_NAME
+#define UPDATE_NAME ""
+#endif

src/network/connection.cpp

@@ -23,6 +23,8 @@
 
 #include "connection.h"
 
+#include <string_view>
+
 #include "GlobalVars.h"
 #include "logging/Logger.h"
 #include "packets.h"
@@ -165,8 +167,12 @@ bool Connection::sendPacketNumber() {
 bool Connection::sendShortString(const char* str) {
 	uint8_t size = strlen(str);
 
+	assert(size <= 255);
+
 	MUST_TRANSFER_BOOL(sendByte(size));
-	MUST_TRANSFER_BOOL(sendBytes((const uint8_t*)str, size));
+	if (size > 0) {
+		MUST_TRANSFER_BOOL(sendBytes((const uint8_t*)str, size));
+	}
 
 	return true;
 }
@@ -373,6 +379,16 @@ void Connection::sendTrackerDiscovery() {
 			// Tracker type to hint the server if it's a glove or normal tracker or
 			// something else
 			MUST_TRANSFER_BOOL(sendByte(static_cast<uint8_t>(TRACKER_TYPE)));
+			static_assert(std::string_view{VENDOR_NAME}.size() <= 255);
+			MUST_TRANSFER_BOOL(sendShortString(VENDOR_NAME));
+			static_assert(std::string_view{VENDOR_URL}.size() <= 255);
+			MUST_TRANSFER_BOOL(sendShortString(VENDOR_URL));
+			static_assert(std::string_view{PRODUCT_NAME}.size() <= 255);
+			MUST_TRANSFER_BOOL(sendShortString(PRODUCT_NAME));
+			static_assert(std::string_view{UPDATE_ADDRESS}.size() <= 255);
+			MUST_TRANSFER_BOOL(sendShortString(UPDATE_ADDRESS));
+			static_assert(std::string_view{UPDATE_NAME}.size() <= 255);
+			MUST_TRANSFER_BOOL(sendShortString(UPDATE_NAME));
 			return true;
 		},
 		0
@@ -751,7 +767,8 @@ void Connection::update() {
 				auto& sensors = sensorManager.getSensors();
 
 				if (sensorId >= sensors.size()) {
-					m_Logger.warn("Invalid sensor config flag packet: invalid sensor id"
+					m_Logger.warn(
+						"Invalid sensor config flag packet: invalid sensor id"
 					);
 					break;
 				}

src/serial/serialcommands.cpp

@@ -296,6 +296,8 @@ void cmdGet(CmdParser* parser) {
 		const char* mag = sensor0->getAttachedMagnetometer();
 		if (mag) {
 			logger.info("[TEST] Sensor[0] magnetometer: %s", mag);
+		} else {
+			logger.info("[TEST] Sensor[0] has no magnetometer attached");
 		}
 
 		if (!sensor0->getHadData()) {