From 3bdb7a7f2de849b29d402d2b8e7428155e99ba28 Mon Sep 17 00:00:00 2001
From: StapleButter <thetotalworm@gmail.com>
Date: Mon, 18 Dec 2017 23:24:45 +0100
Subject: [PATCH] hook up the LAN (pcap) interface

---
 src/WifiAP.cpp             | 77 +++++++++++++++++++++++++++++++++++++-
 src/libui_sdl/Platform.cpp |  4 +-
 2 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/src/WifiAP.cpp b/src/WifiAP.cpp
index bebb0b5b..14724250 100644
--- a/src/WifiAP.cpp
+++ b/src/WifiAP.cpp
@@ -21,6 +21,7 @@
 #include "NDS.h"
 #include "Wifi.h"
 #include "WifiAP.h"
+#include "Platform.h"
 
 
 namespace WifiAP
@@ -71,6 +72,8 @@ u8 PacketBuffer[2048];
 int PacketLen;
 int RXNum;
 
+u8 LANBuffer[2048];
+
 // this is a lazy AP, we only keep track of one client
 // 0=disconnected 1=authenticated 2=associated
 int ClientStatus;
@@ -106,6 +109,11 @@ bool MACEqual(u8* a, u8* b)
     return (*(u32*)&a[0] == *(u32*)&b[0]) && (*(u16*)&a[4] == *(u16*)&b[4]);
 }
 
+bool MACIsBroadcast(u8* a)
+{
+    return (*(u32*)&a[0] == 0xFFFFFFFF) && (*(u16*)&a[4] == 0xFFFF);
+}
+
 
 void USTimer()
 {
@@ -274,8 +282,34 @@ int SendPacket(u8* data, int len)
         return 0;
 
     case 2: // data
-        // TODO: forward to LAN
-        break;
+        {
+            if ((framectl & 0x0300) != 0x0100)
+            {
+                printf("wifiAP: got data frame with bad fromDS/toDS bits %04X\n", framectl);
+                return 0;
+            }
+
+            // TODO: WFC patch??
+
+            if (*(u32*)&data[24] == 0x0003AAAA && *(u16*)&data[28] == 0x0000)
+            {
+                if (ClientStatus != 2)
+                {
+                    printf("wifiAP: trying to send shit without being associated\n");
+                    return 0;
+                }
+
+                int lan_len = (len - 30 - 4) + 14;
+
+                memcpy(&LANBuffer[0], &data[16], 6); // destination MAC
+                memcpy(&LANBuffer[6], &data[10], 6); // source MAC
+                *(u16*)&LANBuffer[12] = *(u16*)&data[30]; // type
+                memcpy(&LANBuffer[14], &data[32], lan_len - 14);
+
+                Platform::LAN_SendPacket(LANBuffer, lan_len);
+            }
+        }
+        return len;
     }
 
     return 0;
@@ -337,6 +371,45 @@ int RecvPacket(u8* data)
         return len+12;
     }
 
+    if (ClientStatus < 2) return 0;
+
+    int rxlen = Platform::LAN_RecvPacket(LANBuffer);
+    if (rxlen > 0)
+    {
+        // check destination MAC
+        if (!MACIsBroadcast(&LANBuffer[0]))
+        {
+            if (!MACEqual(&LANBuffer[0], Wifi::GetMAC()))
+                return 0;
+        }
+
+        // packet is good
+
+        u8* base = data + 12;
+        u8* p = base;
+
+        PWRITE_16(p, 0x0208);
+        PWRITE_16(p, 0x0000); // duration??
+        PWRITE_MAC2(p, (&LANBuffer[0])); // recv
+        PWRITE_MAC2(p, APMac); // BSSID
+        PWRITE_MAC2(p, (&LANBuffer[6])); // sender
+        PWRITE_SEQNO(p);
+
+        PWRITE_32(p, 0x0003AAAA);
+        PWRITE_16(p, 0x0000);
+        PWRITE_16(p, *(u16*)&LANBuffer[12]);
+        memcpy(p, &LANBuffer[14], rxlen-14); p += rxlen-14;
+
+        PALIGN_4(p, base);
+        PWRITE_32(p, 0xDEADBEEF); // checksum. doesn't matter for now
+
+        int len = PLEN(p, base);
+        p = data;
+        PWRITE_TXH(p, len, 20);
+
+        return len+12;
+    }
+
     return 0;
 }
 
diff --git a/src/libui_sdl/Platform.cpp b/src/libui_sdl/Platform.cpp
index c5985de0..f84f8f4f 100644
--- a/src/libui_sdl/Platform.cpp
+++ b/src/libui_sdl/Platform.cpp
@@ -408,11 +408,11 @@ int LAN_SendPacket(u8* data, int len)
 
 void LAN_RXCallback(u_char* blarg, const struct pcap_pkthdr* header, const u_char* data)
 {
+    while (PCapRXNum > 0);
+
     PCapPacketLen = header->len;
     memcpy(PCapPacketBuffer, data, PCapPacketLen);
     PCapRXNum = 1;
-
-    printf("received shit\n");
 }
 
 int LAN_RecvPacket(u8* data)