/* ###
 * IP: GHIDRA
 * NOTE: mentions GNU libbfd, the hard-coded binary is a toy function that generates primes
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// Dump the raw pcode instructions

// Root include for parsing using SLEIGH
#include "loadimage.hh"
#include "sleigh.hh"
#include "emulate.hh"
#include <iostream>

using std::cerr;
using std::cout;

namespace ghidra {

// These are the bytes for an example x86 binary
// These bytes are loaded at address 0x80483b4
static uint1 myprog[] = {
  0x8d, 0x4c, 0x24, 0x04, 0x83, 0xe4, 0xf0, 0xff, 0x71, 0xfc, 0x55,
  0x89, 0xe5, 0x51, 0x81, 0xec, 0xb4, 0x01, 0x00, 0x00, 0xc7, 0x45, 0xf4,
  0x00, 0x00, 0x00, 0x00, 0xeb, 0x12, 0x8b, 0x45, 0xf4, 0xc7, 0x84,
  0x85, 0x64, 0xfe, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x83, 0x45, 0xf4,
  0x01, 0x83, 0x7d, 0xf4, 0x63, 0x7e, 0xe8, 0xc7, 0x45, 0xf4, 0x02,
  0x00, 0x00, 0x00, 0xeb, 0x28, 0x8b, 0x45, 0xf4, 0x01, 0xc0, 0x89, 0x45,
  0xf8, 0xeb, 0x14, 0x8b, 0x45, 0xf8, 0xc7, 0x84, 0x85, 0x64, 0xfe,
  0xff, 0xff, 0x01, 0x00, 0x00, 0x00, 0x8b, 0x45, 0xf4, 0x01, 0x45, 0xf8,
  0x83, 0x7d, 0xf8, 0x63, 0x7e, 0xe6, 0x83, 0x45, 0xf4, 0x01, 0x83,
  0x7d, 0xf4, 0x31, 0x7e, 0xd2, 0xc7, 0x04, 0x24, 0x40, 0x85, 0x04, 0x08,
  0xe8, 0x9c, 0xfe, 0xff, 0xff, 0xc7, 0x45, 0xf4, 0x02, 0x00, 0x00,
  0x00, 0xeb, 0x25, 0x8b, 0x45, 0xf4, 0x8b, 0x84, 0x85, 0x64, 0xfe, 0xff,
  0xff, 0x85, 0xc0, 0x75, 0x13, 0x8b, 0x45, 0xf4, 0x89, 0x44, 0x24,
  0x04, 0xc7, 0x04, 0x24, 0x47, 0x85, 0x04, 0x08, 0xe8, 0x62, 0xfe, 0xff,
  0xff, 0x83, 0x45, 0xf4, 0x01, 0x83, 0x7d, 0xf4, 0x63, 0x7e, 0xd5,
  0x81, 0xc4, 0xb4, 0x01, 0x00, 0x00, 0x59, 0x5d, 0x8d, 0x61, 0xfc, 0xc3,
  0x90, 0x90, 0x90, 0x90, 0x55, 0x89, 0xe5, 0x5d, 0xc3, 0x8d, 0x74,
  0x26, 0x00, 0x8d, 0xbc, 0x27, 0x00, 0x00, 0x00, 0x00, 0x55, 0x89, 0xe5,
  0x57, 0x56, 0x53, 0xe8, 0x5e, 0x00, 0x00, 0x00, 0x81, 0xc3, 0xa5,
  0x11, 0x00, 0x00, 0x83, 0xec, 0x1c, 0xe8, 0xd7, 0xfd, 0xff, 0xff, 0x8d,
  0x83, 0x20, 0xff, 0xff, 0xff, 0x89, 0x45, 0xf0, 0x8d, 0x83, 0x20,
  0xff, 0xff, 0xff, 0x29, 0x45, 0xf0, 0xc1, 0x7d, 0xf0, 0x02, 0x8b, 0x55,
  0xf0, 0x85, 0xd2, 0x74, 0x2b, 0x31, 0xff, 0x89, 0xc6, 0x8d, 0xb6,
  0x00, 0x00, 0x00, 0x00, 0x8b, 0x45, 0x10, 0x83, 0xc7, 0x01, 0x89, 0x44,
  0x24, 0x08, 0x8b, 0x45, 0x0c, 0x89, 0x44, 0x24, 0x04, 0x8b, 0x45,
  0x08, 0x89, 0x04, 0x24, 0xff, 0x16, 0x83, 0xc6, 0x04, 0x39, 0x7d, 0xf0,
  0x75, 0xdf, 0x83, 0xc4, 0x1c, 0x5b, 0x5e, 0x5f, 0x5d, 0xc3, 0x8b,
  0x1c, 0x24, 0xc3, 0x90, 0x90, 0x90, 0x55, 0x89, 0xe5, 0x53, 0xbb, 0x50,
  0x95, 0x04, 0x08, 0x83, 0xec, 0x04, 0xa1, 0x50, 0x95, 0x04, 0x08,
  0x83, 0xf8, 0xff, 0x74, 0x0c, 0x83, 0xeb, 0x04, 0xff, 0xd0, 0x8b, 0x03,
  0x83, 0xf8, 0xff, 0x75, 0xf4, 0x83, 0xc4, 0x04, 0x5b, 0x5d, 0xc3,
  0x55, 0x89, 0xe5, 0x53, 0x83, 0xec, 0x04, 0xe8, 0x00, 0x00, 0x00, 0x00,
  0x5b, 0x81, 0xc3, 0x0c, 0x11, 0x00, 0x00, 0xe8, 0x00, 0xfe, 0xff,
  0xff, 0x59, 0x5b, 0xc9, 0xc3, 0x03, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x72, 0x69, 0x6d, 0x65, 0x73,
  0x00, 0x25, 0x64, 0x0a, 0x00, 0x00
};  // Size of 408 bytes

// This is a tiny LoadImage class which feeds the executable bytes to the translator
class MyLoadImage : public LoadImage {
  uintb baseaddr;
  int4 length;
  uint1 *data;
public:
  MyLoadImage(uintb ad,uint1 *ptr,int4 sz) : LoadImage("nofile") { baseaddr = ad; data = ptr; length = sz; }
  virtual void loadFill(uint1 *ptr,int4 size,const Address &addr);
  virtual string getArchType(void) const { return "myload"; }
  virtual void adjustVma(long adjust) { }
};

// This is the only important method for the LoadImage. It returns bytes from the static array
// depending on the address range requested
void MyLoadImage::loadFill(uint1 *ptr,int4 size,const Address &addr)

{
  uintb start = addr.getOffset();
  uintb max = baseaddr + (length-1);
  for(int4 i=0;i<size;++i) {	// For every byte requestes
    uintb curoff = start + i; // Calculate offset of byte
    if ((curoff < baseaddr)||(curoff>max)) {	// If byte does not fall in window
      ptr[i] = 0;		// return 0
      continue;
    }
    uintb diff = curoff - baseaddr;
    ptr[i] = data[(int4)diff];	// Otherwise return data from our window
  }
}

// -------------------------------
//
// These are the classes/routines relevant to doing disassembly 

// Here is a simple class for emitting assembly.  In this case, we send the strings straight
// to standard out.
class AssemblyRaw : public AssemblyEmit {
public:
  virtual void dump(const Address &addr,const string &mnem,const string &body) {
    addr.printRaw(cout);
    cout << ": " << mnem << ' ' << body << endl;
  }
};

static void dumpAssembly(Translate &trans)

{ // Print disassembly of binary code
  AssemblyRaw assememit;	// Set up the disassembly dumper
  int4 length;			// Number of bytes of each machine instruction

  Address addr(trans.getDefaultCodeSpace(),0x80483b4); // First disassembly address
  Address lastaddr(trans.getDefaultCodeSpace(),0x804846c); // Last disassembly address

  while(addr < lastaddr) {
    length = trans.printAssembly(assememit,addr);
    addr = addr + length;
  }
}

// -------------------------------
//
// These are the classes/routines relevant to printing a pcode translation

// Here is a simple class for emitting pcode. We simply dump an appropriate string representation
// straight to standard out.
class PcodeRawOut : public PcodeEmit {
public:
  virtual void dump(const Address &addr,OpCode opc,VarnodeData *outvar,VarnodeData *vars,int4 isize);
};

static void print_vardata(ostream &s,VarnodeData &data)

{
  s << '(' << data.space->getName() << ',';
  data.space->printOffset(s,data.offset);
  s << ',' << dec << data.size << ')';
}

void PcodeRawOut::dump(const Address &addr,OpCode opc,VarnodeData *outvar,VarnodeData *vars,int4 isize)

{
  if (outvar != (VarnodeData *)0) {
    print_vardata(cout,*outvar);
    cout << " = ";
  }
  cout << get_opname(opc);
  // Possibly check for a code reference or a space reference
  for(int4 i=0;i<isize;++i) {
    cout << ' ';
    print_vardata(cout,vars[i]);
  }
  cout << endl;
}

static void dumpPcode(Translate &trans)

{ // Dump pcode translation of machine instructions
  PcodeRawOut emit;		// Set up the pcode dumper
  AssemblyRaw assememit;	// Set up the disassembly dumper
  int4 length;			// Number of bytes of each machine instruction

  Address addr(trans.getDefaultCodeSpace(),0x80483b4); // First address to translate
  Address lastaddr(trans.getDefaultCodeSpace(),0x80483bf); // Last address

  while(addr < lastaddr) {
    cout << "--- ";
    trans.printAssembly(assememit,addr);
    length = trans.oneInstruction(emit,addr); // Translate instruction
    addr = addr + length;		// Advance to next instruction
  }
}

// -------------------------------------
//
// These are the classes/routines relevant for emulating the executable

// A simple class for emulating the system "puts" call.
// It justs looks up the string data and dumps it to standard out.
class PutsCallBack : public BreakCallBack {
public:
  virtual bool addressCallback(const Address &addr);
};

bool PutsCallBack::addressCallback(const Address &addr)

{
  MemoryState *mem = static_cast<EmulateMemory *>(emulate)->getMemoryState();
  uint1 buffer[256];
  uint4 esp = mem->getValue("ESP");
  AddrSpace *ram = mem->getTranslate()->getSpaceByName("ram");

  uint4 param1 = mem->getValue(ram,esp+4,4);
  mem->getChunk(buffer,ram,param1,255);

  cout << (char *)&buffer << endl;

  uint4 returnaddr = mem->getValue(ram,esp,4);
  mem->setValue("ESP",esp+8);
  emulate->setExecuteAddress(Address(ram,returnaddr));
  
  return true;			// This replaces the indicated instruction
}

// A simple class for emulating the system "printf" call.
// We don't really emulate all of it.  The only printf call in the example
// has an initial string of "%d\n". So we grab the second parameter from the
// memory state and print it as an integer
class PrintfCallBack : public BreakCallBack {
public:
  virtual bool addressCallback(const Address &addr);
};

bool PrintfCallBack::addressCallback(const Address &addr)

{
  MemoryState *mem = static_cast<EmulateMemory *>(emulate)->getMemoryState();

  AddrSpace *ram = mem->getTranslate()->getSpaceByName("ram");

  uint4 esp = mem->getValue("ESP");
  uint4 param2 = mem->getValue(ram,esp+8,4);
  cout << (int4)param2 << endl;

  uint4 returnaddr = mem->getValue(ram,esp,4);
  mem->setValue("ESP",esp+12);
  emulate->setExecuteAddress(Address(ram,returnaddr));

  return true;
}

// A callback that terminates the emulation
class TerminateCallBack : public BreakCallBack {
public:
  virtual bool addressCallback(const Address &addr);
};

bool TerminateCallBack::addressCallback(const Address &addr)

{
  emulate->setHalt(true);

  return true;
}

static void doEmulation(Translate &trans,LoadImage &loader)

{
  // Set up memory state object
  MemoryImage loadmemory(trans.getDefaultCodeSpace(),8,4096,&loader);
  MemoryPageOverlay ramstate(trans.getDefaultCodeSpace(),8,4096,&loadmemory);
  MemoryHashOverlay registerstate(trans.getSpaceByName("register"),8,4096,4096,(MemoryBank *)0);
  MemoryHashOverlay tmpstate(trans.getUniqueSpace(),8,4096,4096,(MemoryBank *)0);

  MemoryState memstate(&trans);	// Instantiate the memory state object
  memstate.setMemoryBank(&ramstate);
  memstate.setMemoryBank(&registerstate);
  memstate.setMemoryBank(&tmpstate);

  BreakTableCallBack breaktable(&trans); // Set up the callback object
  EmulatePcodeCache emulater(&trans,&memstate,&breaktable); // Set up the emulator

  // Set up the initial register state for execution
  memstate.setValue("ESP",0xbffffffc);
  emulater.setExecuteAddress(Address(trans.getDefaultCodeSpace(),0x80483b4));

  // Register callbacks
  PutsCallBack putscallback;
  PrintfCallBack printfcallback;
  TerminateCallBack terminatecallback;
  breaktable.registerAddressCallback(Address(trans.getDefaultCodeSpace(),0x80482c8),&putscallback);
  breaktable.registerAddressCallback(Address(trans.getDefaultCodeSpace(),0x80482b8),&printfcallback);
  breaktable.registerAddressCallback(Address(trans.getDefaultCodeSpace(),0x804846b),&terminatecallback);

  emulater.setHalt(false);

  do {
    emulater.executeInstruction();
  } while(!emulater.getHalt());
}

} // End namespace ghidra

int main(int argc,char **argv)

{
  using namespace ghidra;

  if (argc != 2) {
    cerr << "USAGE:  " << argv[0] << " disassemble" << endl;
    cerr << "        " << argv[0] << " pcode" << endl;
    cerr << "        " << argv[0] << " emulate" << endl;
    return 2;
  }
  string action(argv[1]);

  AttributeId::initialize();
  ElementId::initialize();

  // Set up the loadimage
  MyLoadImage loader(0x80483b4,myprog,408);
  //  loader->open();
  //    loader->adjustVma(adjustvma);

  // Set up the context object
  ContextInternal context;

  // Set up the assembler/pcode-translator
  string sleighfilename = "specfiles/x86.sla";
  Sleigh trans(&loader,&context);

  // Read sleigh file into DOM
  DocumentStorage docstorage;
  Element *sleighroot = docstorage.openDocument(sleighfilename)->getRoot();
  docstorage.registerTag(sleighroot);
  trans.initialize(docstorage); // Initialize the translator

  // Now that context symbol names are loaded by the translator
  // we can set the default context

  context.setVariableDefault("addrsize",1); // Address size is 32-bit
  context.setVariableDefault("opsize",1); // Operand size is 32-bit

  if (action == "disassemble")
    dumpAssembly(trans);
  else if (action == "pcode")
    dumpPcode(trans);
  else if (action == "emulate")
    doEmulation(trans,loader);
  else
    cerr << "Unknown action: "+action << endl;
}

/*
     Example Makefile

--# The C compiler
--CC=gcc
--CXX=g++
--
--# Debug flags
--DBG_CXXFLAGS=-g -Wall -Wno-sign-compare
--
--# Optimization flags
--OPT_CXXFLAGS=-O2 -Wall -Wno-sign-compare
--
--# libraries
--INCLUDES=-I./src
--
--LNK=src/libsla.a
--
--libsla.a:
--	$(MAKE) -C src/ $@
--
--sleighexample.o:	sleighexample.cc
--	$(CXX) -c $(DBG_CXXFLAGS) $(INCLUDES) $< -o $@
--
--sleighexample:	sleighexample.o libsla.a
--	$(CXX) $(DBG_CXXFLAGS) -o sleighexample sleighexample.o $(LNK)
--
--clean:
--	rm -rf *.o sleighexample
--

-a- Welcome to SLEIGH
-a-
-a- The SLEIGH library can be built by invoking the following
-a- from within the "src" directory.
-a-
-a-    make libsla.a
-a-
-a- or the debug target, libsla_dbg.a, can be built.
-a-
-a-
-a- The SLEIGH compiler can be built with:
-a-
-a-    make sleigh_opt
-a-
-a- or the debug target, sleigh_dbg, can be built instead.
-a-
-a-
-a- A tiny example application is provided in the source file
-a- "sleighexample.cc" in the root directory.  It demonstrates
-a- disassembly, pcode translation, and emulation using the SLEIGH
-a- library. It can be built with:
-a-
-a-    make sleighexample
-a-
-a- The "sleighexample" application expects a the x86 specification
-a- file, named "x86.sla", to be in the "specfiles" directory.
-a- Or, you can easily change the hard coded string in main.
-a-
-a- The "sleighexample" application contains a tiny example of how to derive
-a- a tailored LoadImage class in order to get executable bytes to the SLEIGH
-a- translator and your application.  A more sophisticated example that wraps
-a- GNU's Binary File Descriptor library (libbfd) is available in the files
-a- "loadimage_bfd.hh" and "loadimage_bfd.cc"
 */
