101 lines
3.4 KiB
C++
101 lines
3.4 KiB
C++
/*
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* Copyright (C) 2017-2019 Intel Corporation
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*
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* SPDX-License-Identifier: MIT
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*
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*/
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#include "reader.h"
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#include <string.h>
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namespace CLElfLib {
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CElfReader::CElfReader(ElfBinaryStorage &elfBinary) {
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validateElfBinary(elfBinary);
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}
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void CElfReader::validateElfBinary(ElfBinaryStorage &elfBinary) {
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const char *nameTable = nullptr;
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const char *end = nullptr;
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size_t ourSize = 0u;
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size_t entrySize = 0u;
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size_t indexedSectionHeaderOffset = 0u;
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beginBinary = elfBinary.data();
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if (elfBinary.size() >= sizeof(SElf64Header)) {
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// calculate a pointer to the end
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end = beginBinary + elfBinary.size();
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elf64Header = reinterpret_cast<const SElf64Header *>(elfBinary.data());
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if (!((elf64Header->Identity[ELFConstants::idIdxMagic0] == ELFConstants::elfMag0) &&
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(elf64Header->Identity[ELFConstants::idIdxMagic1] == ELFConstants::elfMag1) &&
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(elf64Header->Identity[ELFConstants::idIdxMagic2] == ELFConstants::elfMag2) &&
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(elf64Header->Identity[ELFConstants::idIdxMagic3] == ELFConstants::elfMag3) &&
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(elf64Header->Identity[ELFConstants::idIdxClass] == static_cast<uint32_t>(E_EH_CLASS::EH_CLASS_64)))) {
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throw ElfException();
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}
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ourSize += elf64Header->ElfHeaderSize;
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} else {
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throw ElfException();
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}
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entrySize = elf64Header->SectionHeaderEntrySize;
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if (elf64Header->SectionNameTableIndex < elf64Header->NumSectionHeaderEntries) {
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indexedSectionHeaderOffset = static_cast<size_t>(elf64Header->SectionHeadersOffset) + (elf64Header->SectionNameTableIndex * entrySize);
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if ((beginBinary + indexedSectionHeaderOffset) <= end) {
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nameTable = beginBinary + indexedSectionHeaderOffset;
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}
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}
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for (uint16_t i = 0u; i < elf64Header->NumSectionHeaderEntries; ++i) {
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indexedSectionHeaderOffset = static_cast<size_t>(elf64Header->SectionHeadersOffset) + (i * entrySize);
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// check section header offset
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if ((beginBinary + indexedSectionHeaderOffset) > end) {
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throw ElfException();
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}
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const SElf64SectionHeader *sectionHeader = nullptr;
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sectionHeader = reinterpret_cast<const SElf64SectionHeader *>(beginBinary + indexedSectionHeaderOffset);
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// check section data
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if ((beginBinary + sectionHeader->DataOffset + sectionHeader->DataSize) > end) {
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throw ElfException();
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}
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// check section name index
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if ((nameTable + sectionHeader->Name) > end) {
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throw ElfException();
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}
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SElf64SectionHeader stringSectionHeader = {0};
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stringSectionHeader.Type = sectionHeader->Type;
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stringSectionHeader.Flags = sectionHeader->Flags;
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stringSectionHeader.DataOffset = sectionHeader->DataOffset;
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stringSectionHeader.DataSize = sectionHeader->DataSize;
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stringSectionHeader.Name = sectionHeader->Name;
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sectionHeaders.push_back(std::move(stringSectionHeader));
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// tally up the sizes
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ourSize += static_cast<size_t>(sectionHeader->DataSize);
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ourSize += static_cast<size_t>(entrySize);
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}
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if (ourSize != elfBinary.size()) {
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throw ElfException();
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}
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}
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char *CElfReader::getSectionData(Elf64_Off dataOffset) {
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return beginBinary + dataOffset;
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}
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const SElf64Header *CElfReader::getElfHeader() {
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return elf64Header;
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}
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} // namespace CLElfLib
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