From 4672106699dfa94cd4733a55f947b3525f6647e0 Mon Sep 17 00:00:00 2001
From: Eric Katzfey <eric.katzfey@modalai.com>
Date: Thu, 20 Jul 2023 13:11:35 -0700
Subject: [PATCH] Added baudrate validation functions to the Serial
 implementations

---
 platforms/nuttx/src/px4/common/SerialImpl.cpp | 26 ++++++++++++++++
 .../src/px4/common/include/SerialImpl.hpp     |  1 +
 platforms/posix/include/SerialImpl.hpp        |  1 +
 platforms/posix/src/px4/common/SerialImpl.cpp | 26 ++++++++++++++++
 platforms/qurt/include/SerialImpl.hpp         |  2 ++
 platforms/qurt/src/px4/SerialImpl.cpp         | 30 +++++++++++++++++++
 6 files changed, 86 insertions(+)

diff --git a/platforms/nuttx/src/px4/common/SerialImpl.cpp b/platforms/nuttx/src/px4/common/SerialImpl.cpp
index 4794e66602..4fcf2e499c 100644
--- a/platforms/nuttx/src/px4/common/SerialImpl.cpp
+++ b/platforms/nuttx/src/px4/common/SerialImpl.cpp
@@ -70,11 +70,32 @@ SerialImpl::~SerialImpl()
 	}
 }
 
+bool SerialImpl::validateBaudrate(uint32_t baudrate)
+{
+	if ((baudrate == 9600) ||
+		(baudrate == 19200) ||
+		(baudrate == 38400) ||
+		(baudrate == 57600) ||
+		(baudrate == 115200) ||
+		(baudrate == 230400) ||
+		(baudrate == 460800) ||
+		(baudrate == 921600)) {
+		return true;
+	}
+
+	return false;
+}
+
 bool SerialImpl::configure()
 {
 	/* process baud rate */
 	int speed;
 
+	if (! validateBaudrate(_baudrate)) {
+		PX4_ERR("ERR: unknown baudrate: %lu", _baudrate);
+		return false;
+	}
+
 	switch (_baudrate) {
 	case 9600:   speed = B9600;   break;
 
@@ -329,6 +350,11 @@ uint32_t SerialImpl::getBaudrate() const
 
 bool SerialImpl::setBaudrate(uint32_t baudrate)
 {
+	if (! validateBaudrate(baudrate)) {
+		PX4_ERR("ERR: invalid baudrate: %lu", baudrate);
+		return false;
+	}
+
 	// check if already configured
 	if ((baudrate == _baudrate) && _open) {
 		return true;
diff --git a/platforms/nuttx/src/px4/common/include/SerialImpl.hpp b/platforms/nuttx/src/px4/common/include/SerialImpl.hpp
index 1cf9fd3bcd..4476cb20a9 100644
--- a/platforms/nuttx/src/px4/common/include/SerialImpl.hpp
+++ b/platforms/nuttx/src/px4/common/include/SerialImpl.hpp
@@ -100,6 +100,7 @@ private:
 	StopBits _stopbits{StopBits::One};
 	FlowControl _flowcontrol{FlowControl::Disabled};
 
+	bool validateBaudrate(uint32_t baudrate);
 	bool configure();
 
 };
diff --git a/platforms/posix/include/SerialImpl.hpp b/platforms/posix/include/SerialImpl.hpp
index ba085f2ef8..93765efac7 100644
--- a/platforms/posix/include/SerialImpl.hpp
+++ b/platforms/posix/include/SerialImpl.hpp
@@ -69,6 +69,7 @@ private:
 	StopBits _stopbits{StopBits::One};
 	FlowControl _flowcontrol{FlowControl::Disabled};
 
+	bool validateBaudrate(uint32_t baudrate);
 	bool configure();
 
 	// Mutex used to lock the read functions
diff --git a/platforms/posix/src/px4/common/SerialImpl.cpp b/platforms/posix/src/px4/common/SerialImpl.cpp
index 7e181de881..ab48a1a58a 100644
--- a/platforms/posix/src/px4/common/SerialImpl.cpp
+++ b/platforms/posix/src/px4/common/SerialImpl.cpp
@@ -36,11 +36,32 @@ SerialImpl::~SerialImpl()
 	}
 }
 
+bool SerialImpl::validateBaudrate(uint32_t baudrate)
+{
+	if ((baudrate == 9600) ||
+		(baudrate == 19200) ||
+		(baudrate == 38400) ||
+		(baudrate == 57600) ||
+		(baudrate == 115200) ||
+		(baudrate == 230400) ||
+		(baudrate == 460800) ||
+		(baudrate == 921600)) {
+		return true;
+	}
+
+	return false;
+}
+
 bool SerialImpl::configure()
 {
 	/* process baud rate */
 	int speed;
 
+	if (! validateBaudrate(_baudrate)) {
+		PX4_ERR("ERR: unknown baudrate: %u", _baudrate);
+		return false;
+	}
+
 	switch (_baudrate) {
 	case 9600:   speed = B9600;   break;
 
@@ -295,6 +316,11 @@ uint32_t SerialImpl::getBaudrate() const
 
 bool SerialImpl::setBaudrate(uint32_t baudrate)
 {
+	if (! validateBaudrate(baudrate)) {
+		PX4_ERR("ERR: invalid baudrate: %u", baudrate);
+		return false;
+	}
+
 	// check if already configured
 	if ((baudrate == _baudrate) && _open) {
 		return true;
diff --git a/platforms/qurt/include/SerialImpl.hpp b/platforms/qurt/include/SerialImpl.hpp
index ebede1f5ed..dadda42e77 100644
--- a/platforms/qurt/include/SerialImpl.hpp
+++ b/platforms/qurt/include/SerialImpl.hpp
@@ -68,6 +68,8 @@ private:
 	StopBits _stopbits{StopBits::One};
 	FlowControl _flowcontrol{FlowControl::Disabled};
 
+	bool validateBaudrate(uint32_t baudrate);
+
 	// Mutex used to lock the read functions
 	//pthread_mutex_t read_mutex;
 
diff --git a/platforms/qurt/src/px4/SerialImpl.cpp b/platforms/qurt/src/px4/SerialImpl.cpp
index 24eb5f4e8b..9ce43e94f2 100644
--- a/platforms/qurt/src/px4/SerialImpl.cpp
+++ b/platforms/qurt/src/px4/SerialImpl.cpp
@@ -32,6 +32,26 @@ SerialImpl::~SerialImpl()
 	}
 }
 
+bool SerialImpl::validateBaudrate(uint32_t baudrate)
+{
+	if ((baudrate != 9600)   &&
+		(baudrate != 38400)  &&
+		(baudrate != 57600)  &&
+		(baudrate != 115200) &&
+		(baudrate != 230400) &&
+		(baudrate != 250000) &&
+		(baudrate != 420000) &&
+		(baudrate != 460800) &&
+		(baudrate != 921600) &&
+		(baudrate != 1000000) &&
+		(baudrate != 1843200) &&
+		(baudrate != 2000000)) {
+		return false;
+	}
+
+	return true;
+}
+
 bool SerialImpl::open()
 {
 	// There's no harm in calling open multiple times on the same port.
@@ -40,6 +60,11 @@ bool SerialImpl::open()
 	_open = false;
 	_serial_fd = -1;
 
+	if (! validateBaudrate(_baudrate)) {
+		PX4_ERR("Invalid baudrate: %u", _baudrate);
+		return false;
+	}
+
 	if (_bytesize != ByteSize::EightBits) {
 		PX4_ERR("Qurt platform only supports ByteSize::EightBits");
 		return false;
@@ -219,6 +244,11 @@ uint32_t SerialImpl::getBaudrate() const
 
 bool SerialImpl::setBaudrate(uint32_t baudrate)
 {
+	if (! validateBaudrate(baudrate)) {
+		PX4_ERR("Invalid baudrate: %u", baudrate);
+		return false;
+	}
+
 	// check if already configured
 	if (baudrate == _baudrate) {
 		return true;