Elf file reader.

Reads the symbols of all sections and provides
addresses to functions and data objects.
 


git-svn-id: https://www4.informatik.uni-erlangen.de/i4svn/danceos/trunk/devel/fail@1592 8c4709b5-6ec9-48aa-a5cd-a96041d1645a

src/core/util/ElfReader.cc

@@ -0,0 +1,114 @@
+#include "ElfReader.hpp"
+#include "elfinfo/elfinfo.h"
+#include <stdio.h>
+
+namespace fail {
+
+ElfReader::ElfReader(const char* path) : m_log("Fail*Elfinfo", false){
+	// Try to open the ELF file
+	FILE * fp = fopen(path, "r");
+  if (!fp) {
+		m_log << "Error: Could not open " << path << std::endl;
+		return;
+	}
+
+  // Evaluate headers	
+	Elf32_Ehdr ehdr;
+	Elf32_Shdr sec_hdr;
+	int num_hdrs,i;
+	fseek(fp,(off_t)0,SEEK_SET);
+	read_ELF_file_header(fp, &ehdr);
+	num_hdrs=ehdr.e_shnum;
+	m_log << "Evaluating ELF File: " << path << std::endl;	
+	// Parse symbol table and generate internal map
+  for(i=0;i<num_hdrs;i++)
+	{
+					if(read_ELF_section_header(i,&sec_hdr,fp)==-1)
+					{
+									m_log << "Wrong Section to read" << std::endl;
+					}
+					else
+					{
+									if((sec_hdr.sh_type==SHT_SYMTAB)||(sec_hdr.sh_type==SHT_DYNSYM))                        
+									{
+													process_symboltable(i,fp);
+
+									}
+									else 
+									{
+													continue;                       
+									}
+					}
+	}
+
+	fclose(fp);
+}
+
+int ElfReader::process_symboltable(int sect_num, FILE* fp){
+
+  Elf32_Shdr sect_hdr;    
+  Elf32_Sym mysym;
+  char *name_buf=NULL;
+  int num_sym,link,i,idx;
+  off_t sym_data_offset;
+  int sym_data_size;
+  if(read_ELF_section_header(sect_num,&sect_hdr,fp)==-1)
+  {
+          return -1;
+  }
+  //we have to check to which strtab it is linked
+  link=sect_hdr.sh_link;
+  sym_data_offset=sect_hdr.sh_offset;
+  sym_data_size=sect_hdr.sh_size;
+  num_sym=sym_data_size/sizeof(Elf32_Sym);        
+  
+  //read the coresponding strtab
+  if(read_ELF_section_header(link,&sect_hdr,fp)==-1)
+  {
+          return -1;
+  }
+  //get the size of strtab in file and allocate a buffer 
+  name_buf=(char*)malloc(sect_hdr.sh_size);
+  if(!name_buf)
+          return -1;
+  //get the offset of strtab in file and seek to it
+  fseek(fp,sect_hdr.sh_offset,SEEK_SET);
+  //read all data from the section to the buffer.
+  fread(name_buf,sect_hdr.sh_size,1,fp);  
+  //so we have the namebuf now seek to symtab data
+  fseek(fp,sym_data_offset,SEEK_SET);
+
+	m_log << "[section " << sect_num << "] contains " << num_sym << " symbols." << std::endl;
+  for(i=0;i<num_sym;i++)
+  {
+                          
+          fread(&mysym,sizeof(Elf32_Sym),1,fp);
+          idx=mysym.st_name;
+
+		   		int type = ELF32_ST_TYPE(mysym.st_info);
+					if((type != STT_SECTION) && (type != STT_FILE)){
+						m_log << " " <<  (i) << " " << name_buf+idx  << " @ "  << mysym.st_value << std::endl;
+						m_map[name_buf+idx] = mysym.st_value;
+					}
+
+	}
+
+  free (name_buf);
+	return 0;
+}
+
+
+guest_address_t ElfReader::getAddressByName(const std::string& name) {
+				if( m_map.find(name) == m_map.end() ) {
+					return -1;
+				}else{
+					return m_map[name];
+				}
+}
+
+std::string getNameByAddress(guest_address_t address) {
+				return "Test";
+}
+
+} // end-of-namespace fail
+