From fc7a25c92a5f3eaec125464963405abd259eb0dd Mon Sep 17 00:00:00 2001
From: Rob Riggs <rob@pangalactic.org>
Date: Thu, 8 Jul 2021 19:50:54 -0500
Subject: [PATCH] Add support for frame resizing. Handle old stream frame type
 in encoder.

---
 TNC/HdlcFrame.hpp       |  3 +--
 TNC/M17Encoder.cpp      |  6 ++++++
 TNC/SegmentedBuffer.hpp | 17 +++++++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/TNC/HdlcFrame.hpp b/TNC/HdlcFrame.hpp
index d37dea5..92ee303 100644
--- a/TNC/HdlcFrame.hpp
+++ b/TNC/HdlcFrame.hpp
@@ -101,6 +101,7 @@ public:
     }
 
     uint16_t size() const {return data_.size();}
+    bool resize(uint16_t size) {return data_.resize(size);}
 
     uint16_t crc() const {return crc_;}
     uint16_t fcs() const {return fcs_;}
@@ -170,12 +171,10 @@ public:
             free_list_.pop_front();
         }
         taskEXIT_CRITICAL_FROM_ISR(x);
-        DEBUG("Acquired frame %p (size after = %d)", result, free_list_.size());
         return result;
     }
 
     void release(frame_type* frame) {
-        DEBUG("Released frame %p (size before = %d)", frame, free_list_.size());
         frame->clear();
         auto x = taskENTER_CRITICAL_FROM_ISR();
         free_list_.push_back(*frame);
diff --git a/TNC/M17Encoder.cpp b/TNC/M17Encoder.cpp
index a8b45f8..ca9852d 100644
--- a/TNC/M17Encoder.cpp
+++ b/TNC/M17Encoder.cpp
@@ -224,6 +224,12 @@ void M17Encoder::process_stream(tnc::hdlc::IoFrame* frame, FrameType type)
         {
             send_stream(frame, type);   // Consumes frame.
         }
+        else if (frame->size() == 26)
+        {
+            // Old-style frame with trailing CRC.
+            frame->resize(24);
+            send_stream(frame, type);
+        }
         else
         {
             WARN("Unexpected AUDIO frame size = %u", frame->size());
diff --git a/TNC/SegmentedBuffer.hpp b/TNC/SegmentedBuffer.hpp
index b900873..3e0620c 100644
--- a/TNC/SegmentedBuffer.hpp
+++ b/TNC/SegmentedBuffer.hpp
@@ -81,6 +81,23 @@ struct SegmentedBuffer {
 
     uint16_t size() const {return size_;}
 
+    bool resize(uint16_t size)
+    {
+        if (size <= size_)
+        {
+            size_ = size;
+        }
+        else
+        {
+            for (;size_ != size;)
+            {
+                if (!push_back(value_type()))
+                    return false;
+            }
+        }
+        return true;
+    }
+
     bool push_back(value_type value) {
         uint16_t offset = size_ & 0xFF;
         if (offset == 0) { // Must allocate.