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#pragma once
#include "elf.h"
#include <util/generic/string.h>
#include <util/stream/file.h>
#include <util/system/filemap.h>
namespace NElf {
template<typename TTo, typename TFrom>
inline TTo Offset(TFrom from, size_t off) {
return reinterpret_cast<TTo>(reinterpret_cast<char*>(from) + off);
}
bool IsElf(const TString& path);
class TElf {
public:
TElf(const TString& path)
: Map(path, TFileMap::oRdWr)
{
Map.Map(0, Map.Length());
Begin = reinterpret_cast<char*>(Map.Ptr());
if (Map.Length() < static_cast<i64>(sizeof(Elf64_Ehdr)) || TStringBuf(Begin, SELFMAG) != ELFMAG) {
ythrow yexception() << path << " is not an ELF file";
}
}
Elf64_Ehdr* GetHeader() const noexcept {
return reinterpret_cast<Elf64_Ehdr*>(Begin);
}
char* GetPtr(size_t offset = 0) const noexcept {
return Begin + offset;
}
Elf64_Shdr* GetSectionByType(Elf64_Word type) const {
Elf64_Shdr* r = nullptr;
for (Elf64_Shdr* p = GetSectionBegin(), *end = GetSectionEnd(); p != end; ++p) {
if (p->sh_type == type) {
if (r) {
ythrow yexception() << "More than one section of type " << type << Endl;
}
r = p;
}
}
return r;
}
size_t GetSectionCount() const noexcept {
size_t count = GetHeader()->e_shnum;
if (count == 0) {
count = GetSection(0)->sh_size;
}
return count;
}
Elf64_Shdr* GetSectionBegin() const noexcept {
return reinterpret_cast<Elf64_Shdr*>(Begin + GetHeader()->e_shoff);
}
Elf64_Shdr* GetSectionEnd() const noexcept {
return reinterpret_cast<Elf64_Shdr*>(Begin + GetHeader()->e_shoff) + GetSectionCount();
}
Elf64_Shdr* GetSection(size_t i) const noexcept {
return GetSectionBegin() + i;
}
Elf64_Shdr* GetSectionsNameSection() const noexcept {
size_t index = GetHeader()->e_shstrndx;
if (index == SHN_XINDEX) {
index = GetSection(0)->sh_link;
}
return GetSection(index);
}
private:
TFileMap Map;
char* Begin;
};
class TSection {
public:
TSection(TElf* elf, Elf64_Shdr* this_)
: Elf(elf)
, This(this_)
{
}
bool IsNull() const noexcept {
return !This;
}
char* GetPtr(size_t offset = 0) const noexcept {
return Elf->GetPtr(This->sh_offset) + offset;
}
TStringBuf GetStr(size_t offset) const noexcept {
return GetPtr(offset);
}
TStringBuf GetName() const noexcept {
return TSection{Elf, Elf->GetSectionsNameSection()}.GetPtr(This->sh_name);
}
size_t GetLink() const noexcept {
return This->sh_link;
}
size_t GetSize() const noexcept {
return This->sh_size;
}
size_t GetEntryCount() const noexcept {
return GetSize() / This->sh_entsize;
}
template<typename TTo = char>
TTo* GetEntry(size_t i) const noexcept {
return reinterpret_cast<TTo*>(GetPtr(i * This->sh_entsize));
}
private:
TElf* Elf;
Elf64_Shdr* This;
};
class TVerneedSection : public TSection {
public:
TVerneedSection(TElf* elf)
: TSection(elf, elf->GetSectionByType(SHT_GNU_verneed))
{
}
Elf64_Verneed* GetFirstVerneed() const noexcept {
if (!GetSize()) {
return nullptr;
}
return reinterpret_cast<Elf64_Verneed*>(GetPtr());
}
Elf64_Verneed* GetNextVerneed(Elf64_Verneed* v) const noexcept {
if (!v->vn_next) {
return nullptr;
}
return Offset<Elf64_Verneed*>(v, v->vn_next);
}
Elf64_Vernaux* GetFirstVernaux(Elf64_Verneed* v) const noexcept {
if (!v->vn_cnt) {
return nullptr;
}
return Offset<Elf64_Vernaux*>(v, v->vn_aux);
}
Elf64_Vernaux* GetNextVernaux(Elf64_Vernaux* v) const noexcept {
if (!v->vna_next) {
return nullptr;
}
return Offset<Elf64_Vernaux*>(v, v->vna_next);
}
};
}
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