Ingeniería inversa del protocolo chino de transceptor IR USB

bool __cdecl Java_com_icontrol_dev_TiqiaaUsbController_usbSendCmd(JNIEnv *env, jobject obj, struct UsbDeviceConnection *usbdeviceconnection, struct UsbEndpoint *usbendpoint, int cmdType, int cmdId)
{
  char v6; // r5@5
  bool result; // r0@12
  char data[24]; // [sp+8h] [bp-18h]@12

  dword_B57C = 0;
  if ( UsbEndpoint_bulkTransfer )
  {
    if ( usbdeviceconnection )
    {
      if ( usbendpoint )
      {
        switch ( cmdType )
        {
          case 0:
            v6 = 'L';
            goto LABEL_12;
          case 2:
            v6 = 'R';
            goto LABEL_12;
          case 3:
            v6 = 'H';
            goto LABEL_12;
          case 4:
            v6 = 'O';
            goto LABEL_12;
          case 6:
            v6 = 'C';
            goto LABEL_12;
          case 7:
            v6 = 'V';
            goto LABEL_12;
          case 1:
            v6 = 'S';
LABEL_12:
            data[0] = 'S';
            data[1] = 'T';
            data[3] = v6;
            data[2] = cmdId;
            data[4] = 'E';
            data[5] = 'N';
            result = sub_3528(env, usbdeviceconnection, usbendpoint, data, 6);
            break;
          default:
            result = 0;
            break;
        }
      }
      else
      {
        result = 0;
      }
    }
    else
    {
      result = 0;
    }
  }
  else
  {
    result = UsbEndpoint_bulkTransfer;
  }
  return result;
}

int __cdecl sub_3528(JNIEnv *env, struct UsbDeviceConnection *usbdeviceconnection, struct UsbEndpoint *usbendpoint, void *data, int size)
{
  JNIEnv v5; // r1@1
  JNIEnv *v6; // r4@1
  int result; // r0@2
  int v8; // r2@3
  int tsize; // r7@5
  size_t fragmSize; // r5@9
  int v11; // r0@11
  JNIEnv v12; // r3@11
  int v13; // r6@11
  int rdOffs; // [sp+10h] [bp-80h]@7
  int v15; // [sp+14h] [bp-7Ch]@15
  int jbyteArray; // [sp+18h] [bp-78h]@1
  int fragmCnt; // [sp+1Ch] [bp-74h]@7
  char *_data; // [sp+28h] [bp-68h]@1
  char buf[64]; // [sp+34h] [bp-5Ch]@7
  int _stack_chk_guard; // [sp+74h] [bp-1Ch]@1

  _data = (char *)data;
  v5 = *env;
  v6 = env;
  _stack_chk_guard = ::_stack_chk_guard;
  jbyteArray = ((int (*)(void))v5->NewByteArray)();
  if ( jbyteArray )
  {
    v8 = UsbPackCounter + 1;
    if ( UsbPackCounter + 1 > 15 )
      v8 = 1;
    tsize = size;
    UsbPackCounter = v8;
    if ( size > 1024 )
      tsize = 1024;
    j_j_memset(buf, 0, 0x40u);
    buf[0] = 2;
    buf[3] = (tsize / 56 & 0x7F)
           + ((((tsize + -56 * (tsize / 56 & 0x7F)) >> 31) - (tsize + -56 * (tsize / 56 & 0x7Fu))) >> 31);
    rdOffs = 0;
    fragmCnt = 0;
    buf[2] = UsbPackCounter;
    while ( 1 )
    {
      if ( rdOffs >= tsize )
        goto LABEL_25;
      fragmCnt = (fragmCnt + 1) & 0xFF;
      fragmSize = tsize - rdOffs;
      if ( tsize - rdOffs > 56 )
        fragmSize = 56;
      buf[1] = fragmSize + 3;
      buf[4] = fragmCnt;
      j_j_memcpy(&buf[5], &_data[rdOffs], fragmSize);
      ((void (__fastcall *)(JNIEnv *, int, _DWORD, signed int))(*v6)->SetByteArrayRegion)(v6, jbyteArray, 0, 61);
      v11 = ((int (__fastcall *)(JNIEnv *))(*v6)->ExceptionCheck)(v6);
      v12 = *v6;
      v13 = v11;
      if ( v11 )
      {
        ((void (__fastcall *)(JNIEnv *))v12->ExceptionClear)(v6);
        v13 = 0;
        goto return_r6_del;
      }
      if ( !dword_B2A4 )
      {
LABEL_25:
        v13 = 1;
        goto return_r6_del;
      }
      v15 = ((int (__fastcall *)(JNIEnv *))v12->CallIntMethod)(v6);
      if ( ((int (__fastcall *)(JNIEnv *))(*v6)->ExceptionCheck)(v6) )
      {
        ((void (__fastcall *)(JNIEnv *))(*v6)->ExceptionClear)(v6);
        goto return_r6_del;
      }
      if ( v15 < 0 )
        break;
      rdOffs += fragmSize;
    }
    v13 = 0;
return_r6_del:
    ((void (__fastcall *)(JNIEnv *, int))(*v6)->DeleteLocalRef)(v6, jbyteArray);
    result = v13;
  }
  else
  {
    ((void (__fastcall *)(JNIEnv *))(*v6)->ExceptionClear)(v6);
    result = 0;
  }
  if ( _stack_chk_guard != ::_stack_chk_guard )
    j_j___stack_chk_fail(result);
  return result;
}

  buf[0] = 'S';
  buf[1] = 'T';
  buf[2] = cmdId;
  buf[3] = 'D';
  if ( freq > 255 )
  {
    LOBYTE(v36) = 0;
    v37 = -1;
    v38 = 0;
    while ( 1 )
    {
      v39 = (freq - IrFreqTable[v38] + ((freq - IrFreqTable[v38]) >> 31)) ^ ((freq - IrFreqTable[v38]) >> 31);
      if ( v37 != -1 && v39 >= v37 )
      {
        v39 = v37;
      }
      else
      {
        LOBYTE(v36) = v38;
        if ( !v39 )
          break;
      }
      if ( ++v38 == 30 )
        break;
      v37 = v39;
    }
  }
  else
  {
    v36 = (unsigned int)(freq - 1) <= 0x1C ? freq : 0;
  }
  buf[4] = v36;
  v40 = &buf[v22];
  v40[5] = 'E';
  v40[6] = 'N';