/*

* Copyright (c) 2002-2009 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 <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <elfdefs.h>

#include <sys/stat.h>

#if defined(__MSVCDOTNET__) || defined(__TOOLS2__)

#include <iostream>

#include <iomanip>

using namespace std;

#else //(!__MSVCDOTNET__ && !__TOOLS2__) 

#include <iostream.h>

#include <iomanip.h>

#endif //__MSVCDOTNET__

#define ADDR(rtype, p, o) (rtype *)(((char *)p) + o)

bool ignoreSomeSections;

void hexdump(unsigned char* data, int aSize, int offset)

	//  print hex dump of relevant sections

	{

	int i=0;

	int p=0;

	while (i<aSize)	

		{

		int count=0;

		if(p==0){printf("\t%06x   ",offset);} // offset into section

		while (i<aSize && count<4)

			{ 

			printf("%02X", *data);		// print 4 lots of %08x for the data expresed as 32-bit word 

			data++;

			i++;

			count++;

			offset++;

			}

		printf("  ");

		p++;

		if (p==4)

			{

			data=data-16;

			for (int i=0;i<16;i++)			//print 16 bytes of memory interpreted 

				{							//as ASCII characters with all non-printing 

				if (*data>32 && *data <127)	//characters converted to dots

					{

					printf("%1c",*data);

					}

				else

					{

					printf(".");

					}

					data++;

				}

			p=0; 

			printf(" \n "); 

			}

		}

		printf(" \n\n "); 	   	

	}

void print_directive(unsigned char* data, int size)

	// print formatted text of directive section

	{

	printf ("\t");

	for (int i=0; i<size; i++)

		{

		if ((char)data[i]>31 && (char)data[i]<127)

			{

			printf ("%c", (char)data[i]);

			}

		if ((char)data[i]=='\n')

			{

			printf ("\n\t");

			}

		}

	printf ("\n");

	}

void print_reloc(Elf32_Ehdr* eh, Elf32_Sym* symT, unsigned char* strtab)

	// print relocation section

	{

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, eh->e_shoff);

	for (int j=0;j< eh->e_shnum;j++)

		{

		char* sname = ADDR(char, eh, shdr[eh->e_shstrndx].sh_offset);

		if ( (shdr[j].sh_type==9) && 

		     ( (!ignoreSomeSections) || 

		       (strncmp(".rel.debug_", &sname[shdr[j].sh_name], 11))

		     )

		   )

			{

			unsigned char* data = ADDR(unsigned char, eh, shdr[j].sh_offset);

			int noOfReloc=shdr[j].sh_size / shdr[j].sh_entsize;

			printf("\n\n\n\t\t\t%s\n", &sname[shdr[j].sh_name]);

			Elf32_Rel* rl=(Elf32_Rel*)data;				// pointer to relocation section	

			for (int i=0;i<noOfReloc;i++)

				{

				unsigned char* symbolName = strtab;		// pointer to firest element of string											// table which holds symbol names

				Elf32_Sym*  sym = symT;					// pointer to symbol table

				int symTIndx= ELF32_R_SYM(rl->r_info);		// symbol Tableindex

				sym=sym+symTIndx;							

				symbolName=symbolName+sym->st_name;		// index into string table section 

															// with symbol names

				printf("\t0x%08x \t", rl->r_offset);		// prints offset into relocation section

				printf("%d", symTIndx);					// symbol table index

				printf("\t%s\n",symbolName);				// symbol name

				rl++;			

				}

			}

		}

	}	

void print_GlSymbols(Elf32_Ehdr* eh, Elf32_Sym* symT, unsigned char* strtab)

	// print global symbols from Symbol Table

	{	

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, eh->e_shoff);

	char* sname = ADDR(char, eh, shdr[eh->e_shstrndx].sh_offset);

	for (int i=0;i< eh->e_shnum;i++)

		{

		if (!strcmp(".symtab", &sname[shdr[i].sh_name]))

			{

		  	int noOfSym=shdr[i].sh_size / shdr[i].sh_entsize; 	// number of symbols

		  	const char *symName =(const char *)strtab;

		  	int count = 1;										

		  	printf("Global symbols:\n");

		  	printf("=================\n\n");

		  	for (int l=0;l< noOfSym ;l++)

				{

				symT=symT+1;

				if( ELF32_ST_BIND(symT->st_info) == 1)			// searching for global symbols

			 		{

			  		symName = symName + symT->st_name;			// index into string table section 

			 		printf("%d	",count);

			  		printf(symName);

			  		printf("\n");

			  		symName = symName - symT->st_name;			// back to pointing to first byte of string table

			  		count++;

					}

				}

			}

		}

	}

void print_elf_header(Elf32_Ehdr* eh)

	{

	// print elf header

	if (eh->e_version==1)

		printf("\tHeader version: EV_CURRENT (Current version)\n");

	else

		printf("\tInvalid version: EV_NONE (Invalid version)\n");

	if (eh->e_type==0)

		printf("\tFile Type: ET_NONE (No file type) (0)\n");

	else if (eh->e_type==1)

			printf("\tFile Type: ET_REL (Relocatable object) (1)\n");

	else if (eh->e_type==2)

			printf("\tFile Type: ET_EXEC (Executable file) (2)\n"); 

	else if (eh->e_type==3)

			printf("\tFile Type: ET_DYN (Shared object file) (3)\n"); 

	else if (eh->e_type==4)

			printf("\tFile Type: ET_CORE (Core File) (4)\n"); 

	else if (eh->e_type==65280)

			printf("\tFile Type: ET_LOPROC (Precessor Specific) (ff00)\n");

	else	

			printf("\tFile Type: ET_HIPROC (Precessor Specific) (ffff)\n");

	if (eh->e_machine==40)

		printf("\tMachine: EM_ARM (ARM)\n");

	else

		printf("\tERROR:\tUnexpected machine\n");

	printf("\tEntry offset (in SHF_ENTRYSECT section):0x%08x \n",eh->e_entry);

	printf("\tProgram header entries : %d\n",eh->e_phnum); 

	printf("\tSection header entries : %d\n",eh->e_shnum); 

	printf("\tProgram header offset  : %d",eh->e_phoff); 

	printf("  bytes (0x%08X",eh->e_phoff);

	printf(")\n");

	printf("\tSection header offset  : %d",eh->e_shoff); 

	printf("  bytes (0x%08X",eh->e_shoff);

	printf(")\n");

	printf("\tProgram header entry size  : %d",eh->e_phentsize); 

	printf("  bytes (0x%02X",eh->e_phentsize);

	printf(")\n");

	printf("\tSection header entry size  : %d",eh->e_shentsize); 

	printf("  bytes (0x%02X",eh->e_shentsize);

	printf(")\n");

	printf("\tSection header string table index: %d \n", eh->e_shstrndx);

	printf("\tHeader size: %d", eh->e_ehsize);

	printf("  bytes (0x%02X",eh->e_ehsize);

	printf(")\n");

	}

void print_sect_header(char* sname, Elf32_Shdr* shdr, int count)

	// print section header names

	{

	static const char* KtypeName[]={"0","SHT_PROGBITS (1)","SHT_SYMTAB (2)","SHT_STRTAB (3)",

								  "SHT_RELA (4)","5",	"SHT_DINAMIC (6)","7","8","SHT_REL (9)",

								  "10","SHT_DINSYM (11)"};

	printf("\n\n\tName\t\t:%1s\n ",&sname[shdr[count].sh_name]);

	printf("\tType\t\t: %s\n",  KtypeName[shdr[count].sh_type]);

	printf("\tAddr\t\t: 0x%08X\n",shdr[count].sh_addr);

	printf("\tSize\t\t: %1d", shdr[count].sh_size);

	printf("  bytes (0x%X",shdr[count].sh_size);

	printf(")\n");

	printf("\tEntry Size\t: %1d\n",shdr[count].sh_entsize);

	printf("\tAligment\t: %1d\n\n\n",shdr[count].sh_addralign);		 	

	}

unsigned char* findSymbolStringT(Elf32_Ehdr* eh)

	//calculate and return pointer to the first byte of string table(the one with symbol names)

	{

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, eh->e_shoff);

	char* sname = ADDR(char, eh, shdr[eh->e_shstrndx].sh_offset);

	for (int i=0;i < eh->e_shnum; i++)

		{

		if (!strcmp(".strtab", &sname[shdr[i].sh_name]))

			{

			unsigned char* data = ADDR(unsigned char, eh, shdr[i].sh_offset); 

			return data;	//pointer to the first byte of string table section

			}

		}

	return NULL;	//if not found  

	}

Elf32_Sym* findSymbolT(Elf32_Ehdr* eh)

	//calculate and return pointer to the first element of symbol table	

	{

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, eh->e_shoff);

	for (int i=0;i < eh->e_shnum;i++)

		{

		if (shdr[i].sh_type==2)

			{

			unsigned char* data = ADDR(unsigned char, eh, shdr[i].sh_offset);

			Elf32_Sym* sym=(Elf32_Sym*)data;

			return sym;		//pointer to the first element of symbol table.

			}

		}

	return NULL; // if not found

	}

void print_Summary(Elf32_Ehdr* eh)

	{

	//print section names

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, eh->e_shoff);

	char* sname = ADDR(char, eh, shdr[eh->e_shstrndx].sh_offset);

	printf("\nSummary: \n");

	printf("==========\n");

	for (int i=0;i< eh->e_shnum;i++)

		{

		printf(&sname[shdr[i].sh_name]);

		printf("\n");

		}

	}

bool printAll;

int do_elf_file(char* buffer, char* name)

	{

	Elf32_Ehdr* eh=(Elf32_Ehdr *)buffer;	//elf header

	if (eh->e_ident[EI_MAG0] !=0x7f || eh->e_ident[EI_MAG1] != 0x45 || eh->e_ident[EI_MAG2] !=0x4c || eh->e_ident[EI_MAG3] != 0x46)

		{

		// EI_MAG0 to EI_MAG3 - A files' first 4 bytes hold a 'magic number', identifying the file as an ELF object file. 

		cout << "Error: " << name << " is not a valid ELF file";

		return 1;

		}

	if (eh->e_ident[EI_DATA] == 2)							

		{

		// ELF Header size should be 52 bytes or converted into Big-Endian system 13312

		if (eh->e_ehsize != 13312)

			{

			printf("\tERROR:\tELF Header contains invalid file type\n");

			exit(1);

			}

		// e_ident[EI_DATA] specifies the data encoding of the processor-specific data in the object file.

		printf("\tERROR:\tData encoding ELFDATA2MSB (Big-Endian) not supported\n");

		exit(1);

		}

	if (eh->e_ehsize != 52)

		{

		// ELF Header size should be 52 bytes

        printf("\tERROR:\tELF Header contains invalid file type\n");

        exit(1);

        }

	int shoff = eh->e_shoff;							    // offset of section header table

	Elf32_Shdr* shdr = ADDR(Elf32_Shdr, eh, shoff);			// calculating pointer to Secton Header Table

															// Elf32_Shdr * shdr = (Elf32_Shdr *)(buffer+shoff); 

	int shnum = eh->e_shnum;							    // number of section headers

	int shstrndx = eh->e_shstrndx;

	int snameoffset = shdr[shstrndx].sh_offset;				// offset in file of sections' names

	char* sname = ADDR(char, eh, snameoffset);				// pointer to String Table which holds section names

															// char * sname = (char *)(buffer+snameoffset);

	print_elf_header(eh);									// print Elf Header

	Elf32_Sym* symT= findSymbolT(eh);	// pointer to Symbol table

	if (symT==NULL)

		{

		printf("\nSymbol table not found\n");

		}

	unsigned char* strtab=findSymbolStringT(eh);	// pointer to String table which holds symbol names

	if (strtab==NULL)

		{	

		printf("\nString (the one which holds symbol names) table not found\n");

		}

		print_reloc(eh,symT, strtab);	// print relocation info showing symbol names and

					        // and the name of section in which the relocaton occurs.														

	for(int i = 0; i < shnum; i++)

		{    

		unsigned char* data = ADDR(unsigned char, eh, shdr[i].sh_offset);	//pointer to the first byte in the section

															//unsigned char * data = (unsigned char * )(buffer+shdr[i].sh_offset);

		int size = shdr[i].sh_size;	// section size in bytes

		//print directive section

		if (!strcmp(".directive", &sname[shdr[i].sh_name])) 

			{ 

			print_sect_header(sname, shdr, i);

			print_directive(data,size);

			}

		if (!strcmp(".symtab", &sname[shdr[i].sh_name])) 

			{

			 print_sect_header(sname, shdr, i);	

			 // print global symbols

			 print_GlSymbols(eh,symT, strtab);								

			}

		//print relevant section header names

 		//print hex dump of relevant sections

		if (shdr[i].sh_type==1 || shdr[i].sh_type==4 || shdr[i].sh_type==6 ||

		    shdr[i].sh_type==9 || shdr[i].sh_type==11)

			{

			if (strcmp(".comment", &sname[shdr[i].sh_name])&&

				strcmp(".line", &sname[shdr[i].sh_name])   &&

				strcmp(".hash", &sname[shdr[i].sh_name])   &&

				strcmp(".note", &sname[shdr[i].sh_name])   &&

				strcmp(".directive", &sname[shdr[i].sh_name]) &&

				strncmp(".debug",&sname[shdr[i].sh_name] ,6))

				{

				if ( ! ( (ignoreSomeSections) &&

					 (strncmp(".rel.debug_", &sname[shdr[i].sh_name], 11)==0)

				       )

				   )

					{

					print_sect_header(sname, shdr, i);			

			 	    hexdump(data,size,i);

					}

				}

			}

		if (printAll)		// displays extra information

			{ 	

			if(i!=0)

			 	{

		 	 	print_sect_header(sname, shdr, i);					

		 		hexdump(data,size,i);				

		 		}

		 	}		

		}

	print_Summary(eh);	// print section names

	return 0;

}

int read_ar_element_header(char* ptr)

	{

	int length = strtol(ptr+48,0,10);

	if (strncmp(ptr+58, "\x60\x0A", 2) != 0)

		{

		return -1;

		}

	return length;

	}

int main(int argc, char* argv[])

	{

	char* arg;

	int numberOfOptions=2;

	printAll=0;

	ignoreSomeSections=0;

	if (argc<2)

		{

		cout << "File not specified";

		exit(1);

		}

	else if (argc>numberOfOptions+2)

		{

		cout << "Too many arguments";

		exit(1);

		}

	else

		{

		for (int i=1;i<=argc-2;i++)

			{

			if ( strcmp("-i", argv[i]) ==0 )

				{

				ignoreSomeSections=1;

				}

			else if ( strcmp("-a", argv[i]) ==0 )

				{

				printAll=1;

				}

			}

		arg=argv[argc-1];

		}

	struct stat results;

	stat(arg, &results); 

	FILE *elffile;

	if((elffile  = fopen(arg, "rb" )) == NULL)

   		{

   		cout << "Error opening file " << arg;

		exit (1); 

   		}

	char* buffer=new  char [results.st_size];//allocating enough memory 

	fread( buffer, sizeof( char ), results.st_size, elffile);

	fclose(elffile);						

	if (strncmp(buffer, "!<arch>\x0A", 8) != 0)

		{

		// plain ELF file

		if (do_elf_file(buffer, arg) != 0)

			{

			return 1;

			}

		return 0;

		}

	// library file

	char* nextfile = buffer;

	int remainder = results.st_size;

#define ADVANCE(n)	nextfile+=(n); remainder-=(n);

	ADVANCE(8);

	while (remainder > 0)

		{

		int element_length = read_ar_element_header(nextfile);

		ADVANCE(60);

		if (element_length < 0 || element_length > remainder)

			{

			cout << "Error: archive file corrupt";

			return 1;

			}

		if (strncmp(nextfile, "\x7F\x45\x4C\x46",4) == 0)

			{

			if (do_elf_file(nextfile, "archive_element") != 0)

				{

				return 1;

				}

			}

		element_length += element_length&1;	// round up to a multiple of 2

		ADVANCE(element_length);

		}

	return 0;

	}