/*

* Copyright (c) 2001-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include <e32def.h>

#include <e32std.h>

#include "elftran.h"

#include <elfdefs.h>

#include "elffile.h"

#include "elfdll.h"

#include <h_utl.h>

#include <string.h>

#include <stdlib.h>

TBool hadText, hadReloc = EFalse;

ELFFile::ELFFile() 

    :

    iHeapCommittedSize(0x1000),

    iHeapReservedSize(0x100000),

    iStackCommittedSize(0),

    iFileName(0),

    iFileHandle(-1),

    iElfFile(0),

    iDynamicSegmentHdr(0),

    iDynamicSegmentIdx(0),

    iCodeSegmentHdr(0),

    iCodeSegmentIdx(0),

    iDataSegmentHdr(0),

    iDataSegmentIdx(0),

    iDllData(0),

    iCpu(ECpuUnknown)

    {}

ELFFile::~ELFFile()

	{

	delete [] iFileName;

	delete iElfFile;

	delete iDllData;

	}

TBool ELFFile::Init(const TText * const aFileName)

//

// Read the ELF file into memory

//

 	{

 	delete [] iFileName;	

	iFileName = new TText[strlen((const char *)aFileName)+1];

	strcpy ((char *)iFileName, (const char *)aFileName);

	TInt error = HFile::Open(iFileName, &iFileHandle);

	if (error!=0)

		return EFalse;

	TInt flength = HFile::GetLength(iFileHandle);

	iElfFile = (Elf32_Ehdr *)HMem::Alloc(0,flength);

	if (!iElfFile)

		{

		Print(EPeError,"Failed to allocate memory to read in file.\n");

		Close();

		return EFalse;

		}

	if (!HFile::Read(iFileHandle,iElfFile,flength))

		{

		Print(EPeError,"Unable to read file %s.\n",iFileName);

		Close();

		return EFalse;

		}

        Close();

	if (!IsValidFileHeader(iElfFile))

		{

		Print(EPeError,"Invalid file header.\n");

		return EFalse;

		}

	// we only support this....for the moment

	iCpu = ECpuArmV4;

	if (!InitHeaders()) return EFalse;

	if (!InitDllData()) return EFalse;

	iEntryPoint = iElfFile->e_entry;

	iCodeSize = GetCodeSize();

	iDataSize = GetDataSize();

	iBssSize = GetBssSize();

	iStackReservedSize = 0x2000;

	iStackCommittedSize = 0x2000;

 	iLinkedBase = iCodeSegmentHdr->p_vaddr;

	iImageIsDll = iDllData->ImageIsDll();

	return ETrue;

	}

char * ELFFile::CreateImportSection(TInt &aSize)

//

// get ELFDLLData to do it

//

	{

	TInt size;

	char * newSection = iDllData->CreateImportSection(size);

	aSize = size;

	return newSection;

	}

TUint ELFFile::GetExportTableOffset(void)

        {

	return iDllData->GetExportTableOffset();

	}

TBool ELFFile::InitHeaders(void)

        {

	TInt nphdrs = iElfFile->e_phnum;

	if (nphdrs)

	       {

	       // Find the dynamic segment

	       Elf32_Phdr * aPhdr = ELFADDR(Elf32_Phdr, iElfFile, iElfFile->e_phoff);

	       iPhdr = aPhdr;

	       for (TInt idx = 0; idx < nphdrs; idx++)

					{

					Elf32_Word ptype = aPhdr[idx].p_type;

					if (ptype == PT_DYNAMIC)

							{

							iDynamicSegmentHdr = &aPhdr[idx];

							iDynamicSegmentIdx = idx;

							}

      				else if (ptype == PT_LOAD && 

							 (aPhdr[idx].p_flags & (PF_X + PF_ARM_ENTRY)))

							{

							iCodeSegmentHdr = &aPhdr[idx];

							iCodeSegmentIdx = idx;

							}

      				else if (ptype == PT_LOAD && 

							 (aPhdr[idx].p_flags & (PF_W + PF_R)))

							{

							iDataSegmentHdr = &aPhdr[idx];

							iDataSegmentIdx = idx;

							}

					}

	       }

	// cache pointer to symbol table

	// Get section header table

	Elf32_Shdr * s = ELFADDR(Elf32_Shdr, iElfFile, iElfFile->e_shoff);

	// Index of section header for section header string table

	TInt stIdx = iElfFile->e_shstrndx;

	TInt symIdx = -1;

	// Section name string table

	char * stringtable = ELFADDR(char, iElfFile, s[stIdx].sh_offset);

	// the index at which we find '.symtab' is the index of the symtab section

	for (TInt idx = 0; idx < iElfFile->e_shnum; idx++)

	    {

		if (idx != stIdx)

		       {

		       if (!strcmp(&stringtable[s[idx].sh_name], ".symtab"))

			      {

			      symIdx = idx;

			      break;

			      }

		       }

		}

	if (symIdx == -1) return EFalse;

	// save section header table

	iSectionHeaderTable = s;

	// save the index

	iSymIdx = symIdx;	

	// here's the symbol table

	iSymTab = ELFADDR(Elf32_Sym, iElfFile, s[symIdx].sh_offset);

	return ETrue;

	}

TBool ELFFile::InitDllData(void)

	{

	if (!iDynamicSegmentHdr)

	       {

#if defined(_DEBUG)

	       Print(EWarning, "Image '%s' has no import/export data.\n", iFileName);

#endif

	       return ETrue;

	       }

	iDllData = new ELFDllData(this);

	if (!iDllData)

	       {

	       Print(EPeError, "Out of memory allocating DLL data\n");

	       return EFalse;

	       }

	Elf32_Dyn * dyn = ELFADDR(Elf32_Dyn, iElfFile, iDynamicSegmentHdr->p_offset);

	TInt idx = 0;

	TInt soNameOffset = 0;

	while(dyn[idx].d_tag != DT_NULL) // best to make it explicit

	       {

	       switch (dyn[idx].d_tag)

		      {

		      case DT_HASH:

			   iDllData->iHashTable = ELFADDR(Elf32_HashTable, dyn, dyn[idx].d_val);

			   break;

		      case DT_STRTAB:

			   iDllData->iDynStrTab = ELFADDR(char, dyn, dyn[idx].d_val);

			   break;

		      case DT_SYMTAB:

			   iDllData->iDynSymTab = ELFADDR(Elf32_Sym, dyn, dyn[idx].d_val);

			   break;

		      case DT_RELA:

			   iDllData->iRela = ELFADDR(Elf32_Rela, dyn, dyn[idx].d_val);

			   break;

		      case DT_RELASZ:

			   iDllData->iRelaSz = dyn[idx].d_val;

			   break;

		      case DT_RELAENT:

			   iDllData->iRelaSz = dyn[idx].d_val;

			   break;

		      case DT_STRSZ:

			   iDllData->iDynStrTabSize = dyn[idx].d_val;

			   break;

		      case DT_ARM_SYMTABSZ_21: //For RVCT2.1

			   //iDllData->iDynSymTabSize = dyn[idx].d_val;

		      case DT_ARM_SYMTABSZ:

			  /* This is same as DT_ARM_SYMTABSZ_21, but for RVCT 2.2

			   * The tag value has been changed for RVC2.2 from RVCT2.1.

			   * We just ignore this. i.e., we get the symbol table size

			   * from the nchain field of the hash table as noted in section

			   * 3.2.2.2 of the BPABI.

			   */

			   break;

		      case DT_SYMENT:

			   iDllData->iSymSize = dyn[idx].d_val;

			   break;

		      case DT_SONAME:

			   soNameOffset = dyn[idx].d_val;

			   break;

		      case DT_REL:

			   iDllData->iRel = ELFADDR(Elf32_Rel, dyn, dyn[idx].d_val);

			   break;

		      case DT_RELSZ:

			   iDllData->iRelSz = dyn[idx].d_val;

			   break;

		      case DT_RELENT:

			   iDllData->iRelEnt = dyn[idx].d_val;

			   break;

		      case DT_NEEDED:

			   iDllData->AddToDependency(dyn[idx].d_val);

			   break;

		      case DT_PLTRELSZ:

		      case DT_PLTGOT:

		      case DT_INIT:

		      case DT_FINI:

		      case DT_RPATH:

		      case DT_SYMBOLIC:

		      case DT_PLTREL:

		      case DT_DEBUG:

		      case DT_TEXTREL:

		      case DT_JMPREL:

		      case DT_BIND_NOW:

			   break;

		      default:

		           Print(EPeError,"Unrecognized Dyn Array tag in image '%s'.\n", iFileName);

			   return EFalse;

		      }

		      idx++;

	       }

	return iDllData->Init();

	}

void ELFFile::Close()

//

// close the ELF file

//

	{

	HFile::Close(iFileHandle);

	}

TInt ELFFile::NumberOfImports() const

//

// Count the total number of imports for this image

//

	{

	return iDllData->NumberOfImports();

	}

TInt ELFFile::NumberOfImportDlls() const

//

// Count the number of referenced Dlls

//

	{

	return iDllData->NumberOfImportDlls();

	}

TInt ELFFile::NumberOfExports() const

//

// Count the number of exported symbols

//

	{

	return iDllData->NumberOfExports();

	}

TInt ELFFile::NumberOfCodeRelocs() 

	{ 

	return iDllData->NumberOfCodeRelocs(); 

	}

TInt ELFFile::NumberOfDataRelocs() 

	{ 

	return iDllData->NumberOfDataRelocs(); 

	}

Elf32_Phdr * ELFFile::GetSegmentFromAddr(Elf32_Addr addr)

	{

	TInt nphdrs = iElfFile->e_phnum;

	for (TInt idx = 0; idx < nphdrs; idx++)

	        {

		// take advantage of unsignedness 

		if ((addr - iPhdr[idx].p_vaddr) < iPhdr[idx].p_memsz) return &iPhdr[idx];

		}

	return NULL;

	}

TInt ELFFile::NumberOfRelocs()

	{

	return iDllData->NumberOfRelocs();

	}

TUint16 ELFFile::GetRelocType(Elf32_Rel *aReloc)

    {

	// We work out the type by figuring out the segment of the reloc

	TInt segmentIdx = ELF32_R_SYM(aReloc->r_info);

	// check to see if its a reserved or special index.

	if ((!segmentIdx) || ((segmentIdx >= SHN_LORESERVE) && (segmentIdx <= SHN_HIRESERVE)))

		// up until now these have been treated as KInferredRelocType, so lets continue...

		return KInferredRelocType;

	// need to see if this section is executable or writable

	if (iPhdr[segmentIdx-1].p_flags & PF_X) 

		return KTextRelocType;

	if (iPhdr[segmentIdx-1].p_flags & PF_W) 

		return KDataRelocType;

	// perhaps we should error here.

	return KInferredRelocType;

	}

TBool ELFFile::GetRelocs(Elf32_Rel **aCodeRelocs, Elf32_Rel **aDataRelocs)

        {

	return iDllData->GetRelocs(aCodeRelocs, aDataRelocs);

	}

TUint ELFFile::GetCodeSize()

    {

	return iCodeSegmentHdr->p_filesz;

	}

TBool ELFFile::HasInitialisedData()

	{

	return iDataSegmentHdr != NULL && iDataSegmentHdr->p_filesz != 0;

	}

TUint ELFFile::GetDataSize()

    {

	return iDataSegmentHdr != NULL ? iDataSegmentHdr->p_filesz : 0;

	}

TBool ELFFile::HasBssData()

	{

	return iDataSegmentHdr != NULL && (iDataSegmentHdr->p_memsz - iDataSegmentHdr->p_filesz) != 0;

	}

TUint ELFFile::GetBssSize()

    {

	return iDataSegmentHdr != NULL ? iDataSegmentHdr->p_memsz - iDataSegmentHdr->p_filesz: 0;

	}

TBool ELFFile::IsValidFileHeader(Elf32_Ehdr * iElfFile)

 	{

        if (!(iElfFile->e_ident[EI_MAG0] == ELFMAG0 &&

	      iElfFile->e_ident[EI_MAG1] == ELFMAG1 &&

	      iElfFile->e_ident[EI_MAG2] == ELFMAG2 &&

	      iElfFile->e_ident[EI_MAG3] == ELFMAG3))

		{

                Print(EPeError,"Invalid ELF magic.\n");

		return EFalse;

		}

        if (iElfFile->e_ident[EI_CLASS] != ELFCLASS32)

		{

                Print(EPeError,"File is not a 32 bit object file.\n");

		return EFalse;

		}

        if (iElfFile->e_ident[EI_DATA] != ELFDATA2LSB)

		{

                Print(EPeError,"File data encoding is not Little Endian.\n");

		return EFalse;

		}

  	if (iElfFile->e_machine != EM_ARM)

		{

		Print(EPeError,"File does not target ARM/THUMB processors.\n");

		return EFalse;

		}

  	if (!(iElfFile->e_type == ET_EXEC || iElfFile->e_type == ET_DYN))

		{

		Print(EPeError,"File is neither an executable nor a shared object\n");

		return EFalse;

		}

	return ETrue;

	}

// Get details of the next import to fix-up in the current file. Fill in the name of the dll 

//it is imported from, the ordinal number and the address to write back to.

#define ORDINAL_DONE 0x40000000

// The following static functions are passed an array of PE files to operate on

Elf32_Sym * ELFFile::FindSymbol(const TText *aName)

    {

	Elf32_Shdr * s = ELFADDR(Elf32_Shdr, iElfFile, iElfFile->e_shoff);	

	TInt symIdx = iSymIdx;

	Elf32_Sym * sym = iSymTab;

	TInt nSyms = s[symIdx].sh_size / s[symIdx].sh_entsize;

	char * symStringtable = ELFADDR(char, iElfFile, s[s[symIdx].sh_link].sh_offset);

	for (TInt jdx = 0; jdx < nSyms; jdx++)

	    {

		if (!strcmp(&symStringtable[sym[jdx].st_name], (char *)aName)) 

			return &sym[jdx];

		}

	return (Elf32_Sym *)0;

    }

TBool ELFFile::SymbolPresent(TText *aName)

    {

	return (FindSymbol(aName) != 0);

    }

TBool ELFFile::GetExceptionIndexInfo(TUint32 &aOffset)

    {

    const TText * aBase = (TText *)".ARM.exidx$$Base";

    const TText * aLimit = (TText *)".ARM.exidx$$Limit";

	Elf32_Sym * exidxBase = FindSymbol(aBase);

	Elf32_Sym * exidxLimit = FindSymbol(aLimit);

	if (exidxBase && exidxLimit && (exidxLimit->st_value - exidxBase->st_value)) 

	    {

		const TText * aExceptionDescriptor = (TText *)"Symbian$$CPP$$Exception$$Descriptor";

		Elf32_Sym * aED = FindSymbol(aExceptionDescriptor);

		if (aED) 

			{

			// Set bottom bit so 0 in header slot means an old binary.

			// The decriptor is always aligned on a 4 byte boundary.

			aOffset = (aED->st_value - iLinkedBase) | 0x00000001;

			return ETrue;

			}

		else

			{

			Print(EPeError,"Executable has exception table but no exception descriptor\n");

			exit(666);

			}

		}

	return EFalse;

    }

TBool ELFFile::SetUpLookupTable()

{

	if(!iDllData->CreateSymLookupTable() ) {

		Print(EPeError,"Failed to create named symbol lookup information\n");

		return FALSE;

	}

	if(!iDllData->CreateDependency()){

		Print(EPeError,"Failed to create dependency ordering for named symbol lookup\n");

		return FALSE;

	}

	iDllData->SetExportSymInfo();

	return TRUE;

}

void ELFFile::GetExportSymInfoHeader(E32EpocExpSymInfoHdr& aSymInfoHdr)

{

	iDllData->GetExportSymInfoHeader(aSymInfoHdr);

}

void ELFFile::SetLookupTblBase(TInt aBaseOffset)

{

	iDllData->SetLookupTblBase(aBaseOffset);