From 0c635f5132d30f938b424aa30a33a7c8a26d8b5a Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 13 Jun 2016 19:47:45 +0100
Subject: [PATCH] Sanity check the ring buffers.

---
 CWIdTX.cpp   |  2 +-
 DMRTX.cpp    |  2 +-
 DStarTX.cpp  |  2 +-
 SampleRB.cpp | 13 ++++++++++---
 SerialRB.cpp | 13 ++++++++++---
 YSFTX.cpp    |  2 +-
 6 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/CWIdTX.cpp b/CWIdTX.cpp
index de666ec..185d72e 100644
--- a/CWIdTX.cpp
+++ b/CWIdTX.cpp
@@ -101,7 +101,7 @@ void CCWIdTX::process()
 
   uint16_t space = io.getSpace();
     
-  while (space > CYCLE_LENGTH && space <= TX_RINGBUFFER_SIZE) {
+  while (space > CYCLE_LENGTH) {
     bool b = READ_BIT1(m_poBuffer, m_poPtr);
     if (b)
       io.write(TONE, CYCLE_LENGTH);
diff --git a/DMRTX.cpp b/DMRTX.cpp
index a78a966..3406ff6 100644
--- a/DMRTX.cpp
+++ b/DMRTX.cpp
@@ -113,7 +113,7 @@ void CDMRTX::process()
   if (m_poLen > 0U) {
     uint16_t space = io.getSpace();
     
-    while (space > (4U * DMR_RADIO_SYMBOL_LENGTH) && space <= TX_RINGBUFFER_SIZE) {
+    while (space > (4U * DMR_RADIO_SYMBOL_LENGTH)) {
       uint8_t c = m_poBuffer[m_poPtr];
       uint8_t m = m_markBuffer[m_poPtr];
       m_poPtr++;
diff --git a/DStarTX.cpp b/DStarTX.cpp
index c719e97..a319651 100644
--- a/DStarTX.cpp
+++ b/DStarTX.cpp
@@ -266,7 +266,7 @@ void CDStarTX::process()
   if (m_poLen > 0U) {
     uint16_t space = io.getSpace();
     
-    while (space > (8U * DSTAR_RADIO_BIT_LENGTH) && space <= TX_RINGBUFFER_SIZE) {
+    while (space > (8U * DSTAR_RADIO_BIT_LENGTH)) {
       uint8_t c = m_poBuffer[m_poPtr++];
       writeByte(c);
 
diff --git a/SampleRB.cpp b/SampleRB.cpp
index 6494a99..dd9154f 100644
--- a/SampleRB.cpp
+++ b/SampleRB.cpp
@@ -35,12 +35,19 @@ m_overflow(false)
 
 uint16_t CSampleRB::getSpace() const
 {
+  uint16_t n = 0U;
+
   if (m_tail == m_head)
-    return m_full ? 0U : m_length;
+    n = m_full ? 0U : m_length;
   else if (m_tail < m_head)
-    return m_length - m_head + m_tail;
+    n = m_length - m_head + m_tail;
   else
-    return m_tail - m_head;
+    n = m_tail - m_head;
+
+  if (n > m_length)
+    n = 0U;
+
+  return n;
 }
 
 uint16_t CSampleRB::getData() const
diff --git a/SerialRB.cpp b/SerialRB.cpp
index ed11711..5f917d5 100644
--- a/SerialRB.cpp
+++ b/SerialRB.cpp
@@ -39,12 +39,19 @@ void CSerialRB::reset()
 
 uint16_t CSerialRB::getSpace() const
 {
+  uint16_t n = 0U;
+
   if (m_tail == m_head)
-    return m_full ? 0U : m_length;
+    n = m_full ? 0U : m_length;
   else if (m_tail < m_head)
-    return m_length - m_head + m_tail;
+    n = m_length - m_head + m_tail;
   else
-    return m_tail - m_head;
+    n = m_tail - m_head;
+
+  if (n > m_length)
+    n = 0U;
+
+  return n;
 }
 
 uint16_t CSerialRB::getData() const
diff --git a/YSFTX.cpp b/YSFTX.cpp
index a45c8cf..92984a7 100644
--- a/YSFTX.cpp
+++ b/YSFTX.cpp
@@ -77,7 +77,7 @@ void CYSFTX::process()
   if (m_poLen > 0U) {
     uint16_t space = io.getSpace();
     
-    while (space > (4U * YSF_RADIO_SYMBOL_LENGTH) && space <= TX_RINGBUFFER_SIZE) {
+    while (space > (4U * YSF_RADIO_SYMBOL_LENGTH)) {
       uint8_t c = m_poBuffer[m_poPtr++];
       writeByte(c);