API Sysex fixes

Fix memory leaks by using stack instead of malloc
Reduce memory usage by having less temporary bufffers
Remove warnings by adding includes
Decrease code size by 608 bytes (mostly due to not linking malloc)
More robust handling of buffer overflows

2 files changed, 25 insertions, 11 deletions

diff --git a/tmk_core/protocol/lufa/lufa.c b/tmk_core/protocol/lufa/lufa.c
index 0971897706..6dd5959dc4 100644
--- a/tmk_core/protocol/lufa/lufa.c
+++ b/tmk_core/protocol/lufa/lufa.c
@@ -1252,28 +1252,40 @@ void cc_callback(MidiDevice * device,
   // midi_send_cc(device, (chan + 1) % 16, num, val);
 }
 
+#ifdef API_SYSEX_ENABLE
 uint8_t midi_buffer[MIDI_SYSEX_BUFFER] = {0};
+#endif
 
 void sysex_callback(MidiDevice * device, uint16_t start, uint8_t length, uint8_t * data) {
     #ifdef API_SYSEX_ENABLE
         // SEND_STRING("\n");
         // send_word(start);
         // SEND_STRING(": ");
+        // Don't store the header
+        int16_t pos = start - 4;
         for (uint8_t place = 0; place < length; place++) {
             // send_byte(*data);
-            midi_buffer[start + place] = *data;
-            if (*data == 0xF7) {
-                // SEND_STRING("\nRD: ");
-                // for (uint8_t i = 0; i < start + place + 1; i++){
-                //     send_byte(midi_buffer[i]);
-                // SEND_STRING(" ");
-                // }
-                uint8_t * decoded = malloc(sizeof(uint8_t) * (sysex_decoded_length(start + place - 4)));
-                uint16_t decode_length = sysex_decode(decoded, midi_buffer + 4, start + place - 4);
-                process_api(decode_length, decoded);
+            if (pos >= 0) {
+                if (*data == 0xF7) {
+                    // SEND_STRING("\nRD: ");
+                    // for (uint8_t i = 0; i < start + place + 1; i++){
+                    //     send_byte(midi_buffer[i]);
+                    // SEND_STRING(" ");
+                    // }
+                    const unsigned decoded_length = sysex_decoded_length(pos);
+                    uint8_t decoded[API_SYSEX_MAX_SIZE];
+                    sysex_decode(decoded, midi_buffer, pos);
+                    process_api(decoded_length, decoded);
+                    return;
+                }
+                else if (pos >= MIDI_SYSEX_BUFFER) {
+                    return;
+                }
+                midi_buffer[pos] = *data;
             }
             // SEND_STRING(" ");
             data++;
+            pos++;
         }
     #endif
 }
diff --git a/tmk_core/protocol/lufa/lufa.h b/tmk_core/protocol/lufa/lufa.h
index b11854101d..a049fd43c9 100644
--- a/tmk_core/protocol/lufa/lufa.h
+++ b/tmk_core/protocol/lufa/lufa.h
@@ -70,7 +70,6 @@ typedef struct {
 #ifdef MIDI_ENABLE
   void MIDI_Task(void);
   MidiDevice midi_device;
-  #define MIDI_SYSEX_BUFFER 32 
 #endif
 
 #ifdef API_ENABLE
@@ -79,6 +78,9 @@ typedef struct {
 
 #ifdef API_SYSEX_ENABLE
   #include "api_sysex.h"
+  // Allocate space for encoding overhead.
+  //The header and terminator are not stored to save a few bytes of precious ram
+  #define MIDI_SYSEX_BUFFER (API_SYSEX_MAX_SIZE + API_SYSEX_MAX_SIZE / 7 + (API_SYSEX_MAX_SIZE % 7 ? 1 : 0))
 #endif
 
 // #if LUFA_VERSION_INTEGER < 0x120730