301 lines
9.6 KiB
C++
301 lines
9.6 KiB
C++
/*
|
|
Copyright (C) 2001-present by Serge Lamikhov-Center
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated documentation files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in
|
|
all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
THE SOFTWARE.
|
|
*/
|
|
|
|
#ifndef ELFIO_DYNAMIC_HPP
|
|
#define ELFIO_DYNAMIC_HPP
|
|
|
|
#include <algorithm>
|
|
|
|
namespace ELFIO {
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Template class for accessing dynamic sections
|
|
template <class S> class dynamic_section_accessor_template
|
|
{
|
|
public:
|
|
//------------------------------------------------------------------------------
|
|
// Constructor
|
|
explicit dynamic_section_accessor_template( const elfio& elf_file,
|
|
S* section )
|
|
: elf_file( elf_file ), dynamic_section( section ), entries_num( 0 )
|
|
{
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Returns the number of entries in the dynamic section
|
|
Elf_Xword get_entries_num() const
|
|
{
|
|
size_t needed_entry_size = -1;
|
|
if ( elf_file.get_class() == ELFCLASS32 ) {
|
|
needed_entry_size = sizeof( Elf32_Dyn );
|
|
}
|
|
else {
|
|
needed_entry_size = sizeof( Elf64_Dyn );
|
|
}
|
|
|
|
if ( ( 0 == entries_num ) &&
|
|
( 0 != dynamic_section->get_entry_size() &&
|
|
dynamic_section->get_entry_size() >= needed_entry_size ) ) {
|
|
entries_num =
|
|
dynamic_section->get_size() / dynamic_section->get_entry_size();
|
|
Elf_Xword i;
|
|
Elf_Xword tag = DT_NULL;
|
|
Elf_Xword value = 0;
|
|
std::string str;
|
|
for ( i = 0; i < entries_num; i++ ) {
|
|
get_entry( i, tag, value, str );
|
|
if ( tag == DT_NULL )
|
|
break;
|
|
}
|
|
entries_num = std::min<Elf_Xword>( entries_num, i + 1 );
|
|
}
|
|
|
|
return entries_num;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Retrieves an entry from the dynamic section
|
|
bool get_entry( Elf_Xword index,
|
|
Elf_Xword& tag,
|
|
Elf_Xword& value,
|
|
std::string& str ) const
|
|
{
|
|
if ( index >= get_entries_num() ) { // Is index valid
|
|
return false;
|
|
}
|
|
|
|
if ( elf_file.get_class() == ELFCLASS32 ) {
|
|
generic_get_entry_dyn<Elf32_Dyn>( index, tag, value );
|
|
}
|
|
else {
|
|
generic_get_entry_dyn<Elf64_Dyn>( index, tag, value );
|
|
}
|
|
|
|
// If the tag has a string table reference - prepare the string
|
|
if ( tag == DT_NEEDED || tag == DT_SONAME || tag == DT_RPATH ||
|
|
tag == DT_RUNPATH ) {
|
|
string_section_accessor strsec(
|
|
elf_file.sections[get_string_table_index()] );
|
|
const char* result = strsec.get_string( (Elf_Word)value );
|
|
if ( nullptr == result ) {
|
|
str.clear();
|
|
return false;
|
|
}
|
|
str = result;
|
|
}
|
|
else {
|
|
str.clear();
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Adds an entry to the dynamic section
|
|
void add_entry( Elf_Xword tag, Elf_Xword value )
|
|
{
|
|
if ( elf_file.get_class() == ELFCLASS32 ) {
|
|
generic_add_entry_dyn<Elf32_Dyn>( tag, value );
|
|
}
|
|
else {
|
|
generic_add_entry_dyn<Elf64_Dyn>( tag, value );
|
|
}
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Adds an entry with a string value to the dynamic section
|
|
void add_entry( Elf_Xword tag, const std::string& str )
|
|
{
|
|
string_section_accessor strsec(
|
|
elf_file.sections[get_string_table_index()] );
|
|
Elf_Xword value = strsec.add_string( str );
|
|
add_entry( tag, value );
|
|
}
|
|
|
|
private:
|
|
//------------------------------------------------------------------------------
|
|
// Returns the index of the string table
|
|
Elf_Half get_string_table_index() const
|
|
{
|
|
return (Elf_Half)dynamic_section->get_link();
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Retrieves a generic entry from the dynamic section
|
|
template <class T>
|
|
void generic_get_entry_dyn( Elf_Xword index,
|
|
Elf_Xword& tag,
|
|
Elf_Xword& value ) const
|
|
{
|
|
const auto& convertor = elf_file.get_convertor();
|
|
|
|
// Check unusual case when dynamic section has no data
|
|
if ( dynamic_section->get_data() == nullptr ||
|
|
dynamic_section->get_entry_size() < sizeof( T ) ) {
|
|
tag = DT_NULL;
|
|
value = 0;
|
|
return;
|
|
}
|
|
|
|
// Check for integer overflow in size calculation
|
|
if ( index > ( dynamic_section->get_size() /
|
|
dynamic_section->get_entry_size() ) -
|
|
1 ) {
|
|
tag = DT_NULL;
|
|
value = 0;
|
|
return;
|
|
}
|
|
|
|
// Check for integer overflow in pointer arithmetic
|
|
Elf_Xword offset = index * dynamic_section->get_entry_size();
|
|
if ( offset > dynamic_section->get_size() - sizeof( T ) ) {
|
|
tag = DT_NULL;
|
|
value = 0;
|
|
return;
|
|
}
|
|
|
|
const T* pEntry =
|
|
reinterpret_cast<const T*>( dynamic_section->get_data() + offset );
|
|
tag = ( *convertor )( pEntry->d_tag );
|
|
switch ( tag ) {
|
|
case DT_NULL:
|
|
case DT_SYMBOLIC:
|
|
case DT_TEXTREL:
|
|
case DT_BIND_NOW:
|
|
value = 0;
|
|
break;
|
|
case DT_NEEDED:
|
|
case DT_PLTRELSZ:
|
|
case DT_RELASZ:
|
|
case DT_RELAENT:
|
|
case DT_STRSZ:
|
|
case DT_SYMENT:
|
|
case DT_SONAME:
|
|
case DT_RPATH:
|
|
case DT_RELSZ:
|
|
case DT_RELENT:
|
|
case DT_PLTREL:
|
|
case DT_INIT_ARRAYSZ:
|
|
case DT_FINI_ARRAYSZ:
|
|
case DT_RUNPATH:
|
|
case DT_FLAGS:
|
|
case DT_PREINIT_ARRAYSZ:
|
|
value = ( *convertor )( pEntry->d_un.d_val );
|
|
break;
|
|
case DT_PLTGOT:
|
|
case DT_HASH:
|
|
case DT_STRTAB:
|
|
case DT_SYMTAB:
|
|
case DT_RELA:
|
|
case DT_INIT:
|
|
case DT_FINI:
|
|
case DT_REL:
|
|
case DT_DEBUG:
|
|
case DT_JMPREL:
|
|
case DT_INIT_ARRAY:
|
|
case DT_FINI_ARRAY:
|
|
case DT_PREINIT_ARRAY:
|
|
default:
|
|
value = ( *convertor )( pEntry->d_un.d_ptr );
|
|
break;
|
|
}
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Adds a generic entry to the dynamic section
|
|
template <class T>
|
|
void generic_add_entry_dyn( Elf_Xword tag, Elf_Xword value )
|
|
{
|
|
const auto& convertor = elf_file.get_convertor();
|
|
|
|
T entry;
|
|
|
|
switch ( tag ) {
|
|
case DT_NULL:
|
|
case DT_SYMBOLIC:
|
|
case DT_TEXTREL:
|
|
case DT_BIND_NOW:
|
|
entry.d_un.d_val =
|
|
( *convertor )( decltype( entry.d_un.d_val )( 0 ) );
|
|
break;
|
|
case DT_NEEDED:
|
|
case DT_PLTRELSZ:
|
|
case DT_RELASZ:
|
|
case DT_RELAENT:
|
|
case DT_STRSZ:
|
|
case DT_SYMENT:
|
|
case DT_SONAME:
|
|
case DT_RPATH:
|
|
case DT_RELSZ:
|
|
case DT_RELENT:
|
|
case DT_PLTREL:
|
|
case DT_INIT_ARRAYSZ:
|
|
case DT_FINI_ARRAYSZ:
|
|
case DT_RUNPATH:
|
|
case DT_FLAGS:
|
|
case DT_PREINIT_ARRAYSZ:
|
|
entry.d_un.d_val =
|
|
( *convertor )( decltype( entry.d_un.d_val )( value ) );
|
|
break;
|
|
case DT_PLTGOT:
|
|
case DT_HASH:
|
|
case DT_STRTAB:
|
|
case DT_SYMTAB:
|
|
case DT_RELA:
|
|
case DT_INIT:
|
|
case DT_FINI:
|
|
case DT_REL:
|
|
case DT_DEBUG:
|
|
case DT_JMPREL:
|
|
case DT_INIT_ARRAY:
|
|
case DT_FINI_ARRAY:
|
|
case DT_PREINIT_ARRAY:
|
|
default:
|
|
entry.d_un.d_ptr =
|
|
( *convertor )( decltype( entry.d_un.d_val )( value ) );
|
|
break;
|
|
}
|
|
|
|
entry.d_tag = ( *convertor )( decltype( entry.d_tag )( tag ) );
|
|
|
|
dynamic_section->append_data( reinterpret_cast<char*>( &entry ),
|
|
sizeof( entry ) );
|
|
}
|
|
|
|
private:
|
|
// Reference to the ELF file
|
|
const elfio& elf_file;
|
|
// Pointer to the dynamic section
|
|
S* dynamic_section;
|
|
// Number of entries in the dynamic section
|
|
mutable Elf_Xword entries_num;
|
|
};
|
|
|
|
// Type aliases for dynamic section accessors
|
|
using dynamic_section_accessor = dynamic_section_accessor_template<section>;
|
|
using const_dynamic_section_accessor =
|
|
dynamic_section_accessor_template<const section>;
|
|
|
|
} // namespace ELFIO
|
|
|
|
#endif // ELFIO_DYNAMIC_HPP
|