From 1d3ba3e72efcb92b96fe8a8dbfeb839bb738f2c9 Mon Sep 17 00:00:00 2001
From: Loek Le Blansch <loek@pipeframe.xyz>
Date: Sat, 31 Aug 2024 16:50:50 +0200
Subject: more fiddling

---
 captures.txt                    | 19 +++++++++++++++++++
 src/frontend/qt_sdl/LocalMP.cpp | 29 ++++++++++++++---------------
 src/vsr.h                       |  2 ++
 3 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/captures.txt b/captures.txt
index 8028a8c..cc80674 100644
--- a/captures.txt
+++ b/captures.txt
@@ -8,3 +8,22 @@ melon_1714566548.pcap: 1 pixel vertical line, then 1 pixel horizontal line (chec
 
 melon_1714646100.pcap: used to count packet counts for various message sizes
 
+melon_1724322848_instance_0.pcap: Three-way pictochat room
+melon_1724322850_instance_1.pcap
+melon_1724322852_instance_2.pcap
+
+melon_1724411902_MKDS_instance_0.pcap: Mario Kart DS capture (used for differentiating between other games and pictochat traffic)
+melon_1724411904_MKDS_instance_1.pcap
+
+melon_1724421728_instance_0.pcap: Join room A, send message, B, msg, C, msg, D, msg
+melon_1724421730_instance_1.pcap
+
+melon_1725101126_instance_0.pcap: Different message size experiments (new)
+melon_1725101128_instance_1.pcap
+
+melon_1725101595_instance_0.pcap: (Almost) completely pink messages
+melon_1725101597_instance_1.pcap
+
+melon_1725108450_instance_0.pcap: First decoded image
+melon_1725108452_instance_1.pcap
+
diff --git a/src/frontend/qt_sdl/LocalMP.cpp b/src/frontend/qt_sdl/LocalMP.cpp
index 0ca5921..27d1fd4 100644
--- a/src/frontend/qt_sdl/LocalMP.cpp
+++ b/src/frontend/qt_sdl/LocalMP.cpp
@@ -474,14 +474,24 @@ int SendPacketGeneric(u32 type, u8* packet, int len, u64 timestamp)
 #endif
     if (len)
     {
+        u16 game_id = 0x0000;
+        if (len >= 26) game_id = *(u16*)(packet + 0x24);
+        bool pictochat = game_id == 0x03e6;
+
+#ifdef VSR_DROP_RESENDS
+        // resent messages can be dumped completely w/o affecting communication
+        u16 txhdr_new = *(u16*)(packet + 0x02);
+        if (type == 1 && pictochat && txhdr_new == 0) return len;
+#endif
+
 #ifdef VSR_MESSAGE_FIDDLING
-        // if message packet (has size 222 w/o ni-fi header)
-        if (fiddle && len == 222) {
+        u16 pcmeta_type = *(u16*)(packet + 0x2a);
+        if (fiddle && type == 1 && pictochat && pcmeta_type == 2) { // content type is message fragment
             const u8 fill = 0x33; // hot pink (#eb00eb)
             unsigned safe = 0;
 
-            // if content offset == 0 there is some very important info at the
-            // start of the message which must stay intact 
+            // if content offset == 0 only fill from index 0x24 onward (first 8
+            // bytes must stay intact, rest is padding)
             u16 content_offset = *(u16*)(packet + 0x32);
             if (content_offset == 0) {
                 safe = 0x24; // don't touch the first 0x24 bytes
@@ -490,17 +500,6 @@ int SendPacketGeneric(u32 type, u8* packet, int len, u64 timestamp)
             for (size_t i = safe; i < 0xa0; i++) {
                 packet[0x36 + i] = fill;
             }
-
-            // // mainWindow->osdAddMessage(0x00ff00, "oops!");
-            // // NOTE: packet indexes are after NIFI header!
-            // for (size_t i = 0; i < 0x80; i++) {
-            //     packet[0x3e + i] = 0x11;
-            // }
-            // // packet[0x3e + 0x00] = 0x13;
-            // // packet[0x3e + 0x01] = 0x13;
-
-            // // packet[0x3e + 0x02] = 0x33;
-            // // packet[0x3e + 0x04] = 0x33;
         }
 #endif
 
diff --git a/src/vsr.h b/src/vsr.h
index ec57f47..fce78c0 100644
--- a/src/vsr.h
+++ b/src/vsr.h
@@ -11,3 +11,5 @@
 // add "Fiddle" menu bar item
 #define VSR_MESSAGE_FIDDLING
 
+// drop non "new" frames (resends)
+#define VSR_DROP_RESENDS
-- 
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