/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

#include <iostream>
#include <fstream>
#include <set>
#include "pin.H"
using std::string;
using std::hex;
using std::ios;
using std::cerr;
using std::ofstream;
using std::endl;

ofstream OutFile;
ADDRINT newBranchTarget = 0xbeef;
REG rewrite_reg;
std::set<ADDRINT> ipointsCallbacks;
KNOB<string> KnobOutputFile(KNOB_MODE_WRITEONCE, "pintool",
    "o", "indirect_jmp_translation.out", "specify output file name");

IPOINT allIpoints[] = {IPOINT_TAKEN_BRANCH, IPOINT_BEFORE};

VOID PIN_FAST_ANALYSIS_CALL IndirectJumpOrCall(ADDRINT ipoint, ADDRINT pc, ADDRINT isMemoryIndirect, ADDRINT translatedAddr)
{
    if (isMemoryIndirect && translatedAddr == newBranchTarget)
    {
        std::pair<std::set<ADDRINT>::iterator,bool> res = ipointsCallbacks.insert(ipoint);
        if (!res.second)
        {
            // We expect all indirect branches through memory to go to the address at 'newBranchTarget'
            ASSERT(translatedAddr == newBranchTarget, "At PC=" + hexstr(pc) +
                "Too many indirect branches at IPOINT " + decstr(ipoint) +
                " was reported to jump to " + hexstr(newBranchTarget) + "\n");
        }
    }
}


/* Translate memory address 0xfed to the address of newBranchTarget */
ADDRINT PIN_FAST_ANALYSIS_CALL memoryCallback(PIN_MEM_TRANS_INFO* memTransInfo, VOID *v) 
{
    if (memTransInfo->memOpType == PIN_MEMOP_LOAD && memTransInfo->addr == 0xfed)
    {
        return (ADDRINT)&newBranchTarget;
    }

    return (memTransInfo->addr);
}

static ADDRINT TranslateJmpMemRef(ADDRINT ea, ADDRINT stack_ptr)
{
    if (ea == 0xfed)
    {
        // This is where we translate the bad address of
        // "jmp *(0xfed)" to "jmp *(rsp/esp)"
        return stack_ptr;
    }

    return ea;
}

// Pin calls this function every time a new instruction is encountered
VOID Instruction(INS ins, VOID *v)
{
    if (INS_IsIndirectControlFlow(ins))
    {
        OutFile << "Instrumenting at " << hex << INS_Address(ins) << " " << INS_Disassemble(ins).c_str() << std::endl;
        BOOL explicitMemRef = INS_HasExplicitMemoryReference(ins);
        if (explicitMemRef)
        {
            INS_InsertCall(ins, IPOINT_BEFORE, (AFUNPTR)TranslateJmpMemRef,
                IARG_MEMORYOP_EA, 0,
                IARG_REG_VALUE, REG_STACK_PTR,
                IARG_RETURN_REGS, rewrite_reg,
                IARG_END);
            INS_RewriteMemoryOperand(ins, 0, rewrite_reg);
        }

        for (size_t i = 0; i < sizeof(allIpoints)/sizeof(allIpoints[0]); i++)
        {
            INS_InsertCall(ins,
                    allIpoints[i],
                    (AFUNPTR)IndirectJumpOrCall,
                    IARG_FAST_ANALYSIS_CALL,
                    IARG_ADDRINT, (ADDRINT)allIpoints[i],
                    IARG_INST_PTR,
                    IARG_ADDRINT, (ADDRINT)explicitMemRef,
                    IARG_BRANCH_TARGET_ADDR,
                    IARG_END);
        }
    }
}


// This function is called when the application exits
VOID Fini(INT32 code, VOID *v)
{
    for (size_t i = 0; i < sizeof(allIpoints)/sizeof(allIpoints[0]); i++)
    {
        ASSERT(ipointsCallbacks.count(allIpoints[i]) == 1, "Encoutered no translated branches for IPOINT " + decstr((int)allIpoints[i]));
    }
    // Write to a file since cout and cerr maybe closed by the application
    OutFile.setf(ios::showbase);
    OutFile << "Done!" << endl;
    OutFile.close();
}

/* ===================================================================== */
/* Print Help Message                                                    */
/* ===================================================================== */

INT32 Usage()
{
    cerr << "This tool tests memory address translation for indirect call" << endl;
    cerr << endl << KNOB_BASE::StringKnobSummary() << endl;
    return -1;
}

/* ===================================================================== */
/* Main                                                                  */
/* ===================================================================== */

int main(int argc, char * argv[])
{
    // Initialize pin
    if (PIN_Init(argc, argv)) return Usage();

    OutFile.open(KnobOutputFile.Value().c_str());

    rewrite_reg = PIN_ClaimToolRegister();

    // Register Instruction to be called to instrument instructions
    INS_AddInstrumentFunction(Instruction, 0);

    // Register memory callback
    PIN_AddMemoryAddressTransFunction(memoryCallback, NULL);

    // Register Fini to be called when the application exits
    PIN_AddFiniFunction(Fini, 0);

    // Start the program, never returns
    PIN_StartProgram();
}