rarvm.cpp

RAR源码相关

#include "rar.hpp"

#include "rarvmtbl.cpp"

RarVM::RarVM()
{
  Mem=NULL;
}


RarVM::~RarVM()
{
  delete[] Mem;
}


void RarVM::Init()
{
  if (Mem==NULL)
    Mem=new byte[VM_MEMSIZE+4];
}

/*********************************************************************
 IS_VM_MEM macro checks if address belongs to VM memory pool (Mem).
 Only Mem data are always low endian regardless of machine architecture,
 so we need to convert them to native format when reading or writing.
 VM registers have endianness of host machine.
**********************************************************************/
#define IS_VM_MEM(a) (((byte*)a)>=Mem && ((byte*)a)<Mem+VM_MEMSIZE)

inline uint RarVM::GetValue(bool ByteMode,uint *Addr)
{
  if (ByteMode)
  {
#ifdef BIG_ENDIAN
    if (IS_VM_MEM(Addr))
      return(*(byte *)Addr);
    else
      return(*Addr & 0xff);
#else
    return(*(byte *)Addr);
#endif
  }
  else
  {
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT)
    if (IS_VM_MEM(Addr))
    {
      byte *B=(byte *)Addr;
      return UINT32((uint)B[0]|((uint)B[1]<<8)|((uint)B[2]<<16)|((uint)B[3]<<24));
    }
    else
      return UINT32(*Addr);
#else
    return UINT32(*Addr);
#endif
  }
}

#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT)
  #define GET_VALUE(ByteMode,Addr) GetValue(ByteMode,(uint *)Addr)
#else
  #define GET_VALUE(ByteMode,Addr) ((ByteMode) ? (*(byte *)(Addr)):UINT32(*(uint *)(Addr)))
#endif


inline void RarVM::SetValue(bool ByteMode,uint *Addr,uint Value)
{
  if (ByteMode)
  {
#ifdef BIG_ENDIAN
    if (IS_VM_MEM(Addr))
      *(byte *)Addr=Value;
    else
      *Addr=(*Addr & ~0xff)|(Value & 0xff);
#else
    *(byte *)Addr=Value;
#endif
  }
  else
  {
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
    if (IS_VM_MEM(Addr))
    {
      ((byte *)Addr)[0]=(byte)Value;
      ((byte *)Addr)[1]=(byte)(Value>>8);
      ((byte *)Addr)[2]=(byte)(Value>>16);
      ((byte *)Addr)[3]=(byte)(Value>>24);
    }
    else
      *(uint *)Addr=Value;
#else
    *(uint32 *)Addr=Value;
#endif
  }
}

#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
  #define SET_VALUE(ByteMode,Addr,Value) SetValue(ByteMode,(uint *)Addr,Value)
#else
  #define SET_VALUE(ByteMode,Addr,Value) ((ByteMode) ? (*(byte *)(Addr)=(Value)):(*(uint32 *)(Addr)=((uint32)(Value))))
#endif


void RarVM::SetLowEndianValue(uint *Addr,uint Value)
{
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
  ((byte *)Addr)[0]=(byte)Value;
  ((byte *)Addr)[1]=(byte)(Value>>8);
  ((byte *)Addr)[2]=(byte)(Value>>16);
  ((byte *)Addr)[3]=(byte)(Value>>24);
#else
  *(uint32 *)Addr=Value;
#endif
}


inline uint* RarVM::GetOperand(VM_PreparedOperand *CmdOp)
{
  if (CmdOp->Type==VM_OPREGMEM)
    return((uint *)&Mem[(*CmdOp->Addr+CmdOp->Base)&VM_MEMMASK]);
  else
    return(CmdOp->Addr);
}


void RarVM::Execute(VM_PreparedProgram *Prg)
{
  memcpy(R,Prg->InitR,sizeof(Prg->InitR));
  unsigned int GlobalSize=Min(Prg->GlobalData.Size(),VM_GLOBALMEMSIZE);
  if (GlobalSize)
    memcpy(Mem+VM_GLOBALMEMADDR,&Prg->GlobalData[0],GlobalSize);
  unsigned int StaticSize=Min(Prg->StaticData.Size(),VM_GLOBALMEMSIZE-GlobalSize);
  if (StaticSize)
    memcpy(Mem+VM_GLOBALMEMADDR+GlobalSize,&Prg->StaticData[0],StaticSize);

  R[7]=VM_MEMSIZE;
  Flags=0;

  VM_PreparedCommand *PreparedCode=Prg->AltCmd ? Prg->AltCmd:&Prg->Cmd[0];
  if (!ExecuteCode(PreparedCode,Prg->CmdCount))
    PreparedCode[0].OpCode=VM_RET;
  uint NewBlockPos=GET_VALUE(false,&Mem[VM_GLOBALMEMADDR+0x20])&VM_MEMMASK;
  uint NewBlockSize=GET_VALUE(false,&Mem[VM_GLOBALMEMADDR+0x1c])&VM_MEMMASK;
  if (NewBlockPos+NewBlockSize>=VM_MEMSIZE)
    NewBlockPos=NewBlockSize=0;
  Prg->FilteredData=Mem+NewBlockPos;
  Prg->FilteredDataSize=NewBlockSize;

  Prg->GlobalData.Reset();

  uint DataSize=Min(GET_VALUE(false,(uint*)&Mem[VM_GLOBALMEMADDR+0x30]),VM_GLOBALMEMSIZE-VM_FIXEDGLOBALSIZE);
  if (DataSize!=0)
  {
    Prg->GlobalData.Add(DataSize+VM_FIXEDGLOBALSIZE);
    memcpy(&Prg->GlobalData[0],&Mem[VM_GLOBALMEMADDR],DataSize+VM_FIXEDGLOBALSIZE);
  }
}


/*
Note:
  Due to performance considerations RAR VM may set VM_FS, VM_FC, VM_FZ
  incorrectly for byte operands. These flags are always valid only
  for 32-bit operands. Check implementation of concrete VM command
  to see if it sets flags right.
*/

#define SET_IP(IP)                      \
  if ((IP)>=CodeSize)                   \
    return(true);                       \
  if (--MaxOpCount<=0)                  \
    return(false);                      \
  Cmd=PreparedCode+(IP);

bool RarVM::ExecuteCode(VM_PreparedCommand *PreparedCode,int CodeSize)
{
  int MaxOpCount=25000000;
  VM_PreparedCommand *Cmd=PreparedCode;
  while (1)
  {
    uint *Op1=GetOperand(&Cmd->Op1);
    uint *Op2=GetOperand(&Cmd->Op2);
    switch(Cmd->OpCode)
    {
#ifndef NORARVM
      case VM_MOV:
        SET_VALUE(Cmd->ByteMode,Op1,GET_VALUE(Cmd->ByteMode,Op2));
        break;
#ifdef VM_OPTIMIZE
      case VM_MOVB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op2));
        break;
      case VM_MOVD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op2));
        break;
#endif
      case VM_CMP:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1-GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_CMPB:
        {
          uint Value1=GET_VALUE(true,Op1);
          uint Result=UINT32(Value1-GET_VALUE(true,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
      case VM_CMPD:
        {
          uint Value1=GET_VALUE(false,Op1);
          uint Result=UINT32(Value1-GET_VALUE(false,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
#endif
      case VM_ADD:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1+GET_VALUE(Cmd->ByteMode,Op2));
          if (Cmd->ByteMode)
          {
            Result&=0xff;
            Flags=(Result<Value1)|(Result==0 ? VM_FZ:((Result&0x80) ? VM_FS:0));
          }
          else
            Flags=(Result<Value1)|(Result==0 ? VM_FZ:(Result&VM_FS));
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_ADDB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)+GET_VALUE(true,Op2));
        break;
      case VM_ADDD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)+GET_VALUE(false,Op2));
        break;
#endif
      case VM_SUB:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1-GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_SUBB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)-GET_VALUE(true,Op2));
        break;
      case VM_SUBD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)-GET_VALUE(false,Op2));
        break;
#endif
      case VM_JZ:
        if ((Flags & VM_FZ)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JNZ:
        if ((Flags & VM_FZ)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_INC:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)+1);
          if (Cmd->ByteMode)
            Result&=0xff;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_INCB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)+1);
        break;
      case VM_INCD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)+1);
        break;
#endif
      case VM_DEC:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)-1);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_DECB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)-1);
        break;
      case VM_DECD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)-1);
        break;
#endif
      case VM_JMP:
        SET_IP(GET_VALUE(false,Op1));
        continue;
      case VM_XOR:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)^GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_AND:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)&GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_OR:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)|GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_TEST:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)&GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
      case VM_JS:
        if ((Flags & VM_FS)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JNS:
        if ((Flags & VM_FS)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JB:
        if ((Flags & VM_FC)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JBE:
        if ((Flags & (VM_FC|VM_FZ))!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JA:
        if ((Flags & (VM_FC|VM_FZ))==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JAE:
        if ((Flags & VM_FC)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_PUSH:
        R[7]-=4;
        SET_VALUE(false,(uint *)&Mem[R[7]&VM_MEMMASK],GET_VALUE(false,Op1));
        break;
      case VM_POP:
        SET_VALUE(false,Op1,GET_VALUE(false,(uint *)&Mem[R[7] & VM_MEMMASK]));
        R[7]+=4;
        break;
      case VM_CALL:
        R[7]-=4;
        SET_VALUE(false,(uint *)&Mem[R[7]&VM_MEMMASK],Cmd-PreparedCode+1);
        SET_IP(GET_VALUE(false,Op1));
        continue;
      case VM_NOT:
        SET_VALUE(Cmd->ByteMode,Op1,~GET_VALUE(Cmd->ByteMode,Op1));
        break;
      case VM_SHL:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Value2=GET_VALUE(Cmd->ByteMode,Op2);
          uint Result=UINT32(Value1<<Value2);
          Flags=(Result==0 ? VM_FZ:(Result&VM_FS))|((Value1<<(Value2-1))&0x80000000 ? VM_FC:0);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_SHR:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Value2=GET_VALUE(Cmd->ByteMode,Op2);
          uint Result=UINT32(Value1>>Value2);
          Flags=(Result==0 ? VM_FZ:(Result&VM_FS))|((Value1>>(Value2-1))&VM_FC);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_SAR:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Value2=GET_VALUE(Cmd->ByteMode,Op2);
          uint Result=UINT32(((int)Value1)>>Value2);
          Flags=(Result==0 ? VM_FZ:(Result&VM_FS))|((Value1>>(Value2-1))&VM_FC);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_NEG:
        {
          uint Result=UINT32(-GET_VALUE(Cmd->ByteMode,Op1));
          Flags=Result==0 ? VM_FZ:VM_FC|(Result&VM_FS);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_NEGB:
        SET_VALUE(true,Op1,-GET_VALUE(true,Op1));
        break;
      case VM_NEGD:
        SET_VALUE(false,Op1,-GET_VALUE(false,Op1));
        break;
#endif
      case VM_PUSHA:
        {
          const int RegCount=sizeof(R)/sizeof(R[0]);
          for (int I=0,SP=R[7]-4;I<RegCount;I++,SP-=4)
            SET_VALUE(false,(uint *)&Mem[SP & VM_MEMMASK],R[I]);
          R[7]-=RegCount*4;
        }
        break;
      case VM_POPA:
        {
          const int RegCount=sizeof(R)/sizeof(R[0]);
          for (uint I=0,SP=R[7];I<RegCount;I++,SP+=4)
            R[7-I]=GET_VALUE(false,(uint *)&Mem[SP & VM_MEMMASK]);
        }
        break;
      case VM_PUSHF:
        R[7]-=4;
        SET_VALUE(false,(uint *)&Mem[R[7]&VM_MEMMASK],Flags);
        break;
      case VM_POPF:
        Flags=GET_VALUE(false,(uint *)&Mem[R[7] & VM_MEMMASK]);
        R[7]+=4;
        break;
      case VM_MOVZX:
        SET_VALUE(false,Op1,GET_VALUE(true,Op2));
        break;
      case VM_MOVSX:
        SET_VALUE(false,Op1,(signed char)GET_VALUE(true,Op2));
        break;
      case VM_XCHG:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          SET_VALUE(Cmd->ByteMode,Op1,GET_VALUE(Cmd->ByteMode,Op2));
          SET_VALUE(Cmd->ByteMode,Op2,Value1);
        }
        break;
      case VM_MUL:
        {
          uint Result=GET_VALUE(Cmd->ByteMode,Op1)*GET_VALUE(Cmd->ByteMode,Op2);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_DIV:
        {
          uint Divider=GET_VALUE(Cmd->ByteMode,Op2);
          if (Divider!=0)
          {
            uint Result=GET_VALUE(Cmd->ByteMode,Op1)/Divider;
            SET_VALUE(Cmd->ByteMode,Op1,Result);
          }
        }
        break;
      case VM_ADC:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint FC=(Flags&VM_FC);
          uint Result=UINT32(Value1+GET_VALUE(Cmd->ByteMode,Op2)+FC);
          if (Cmd->ByteMode)
            Result&=0xff;
          Flags=(Result<Value1 || Result==Value1 && FC)|(Result==0 ? VM_FZ:(Result&VM_FS));
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_SBB:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint FC=(Flags&VM_FC);
          uint Result=UINT32(Value1-GET_VALUE(Cmd->ByteMode,Op2)-FC);
          if (Cmd->ByteMode)
            Result&=0xff;
          Flags=(Result>Value1 || Result==Value1 && FC)|(Result==0 ? VM_FZ:(Result&VM_FS));
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#endif
      case VM_RET:
        if (R[7]>=VM_MEMSIZE)
          return(true);
        SET_IP(GET_VALUE(false,(uint *)&Mem[R[7] & VM_MEMMASK]));
        R[7]+=4;
        continue;
#ifdef VM_STANDARDFILTERS
      case VM_STANDARD:
        ExecuteStandardFilter((VM_StandardFilters)Cmd->Op1.Data);
        break;
#endif
      case VM_PRINT:
        break;
    }
    Cmd++;
    --MaxOpCount;
  }
}




void RarVM::Prepare(byte *Code,int CodeSize,VM_PreparedProgram *Prg)
{
  InitBitInput();
  memcpy(InBuf,Code,Min(CodeSize,BitInput::MAX_SIZE));

  byte XorSum=0;
  for (int I=1;I<CodeSize;I++)
    XorSum^=Code[I];

  faddbits(8);

  Prg->CmdCount=0;
  if (XorSum==Code[0])
  {
#ifdef VM_STANDARDFILTERS
    VM_StandardFilters FilterType=IsStandardFilter(Code,CodeSize);
    if (FilterType!=VMSF_NONE)
    {
      Prg->Cmd.Add(1);
      VM_PreparedCommand *CurCmd=&Prg->Cmd[Prg->CmdCount++];
      CurCmd->OpCode=VM_STANDARD;
      CurCmd->Op1.Data=FilterType;
      CurCmd->Op1.Addr=&CurCmd->Op1.Data;