/// <summary>
/// Try to read program header.
/// </summary>
/// <exception cref="ObjectDisposedException">
/// Thrown if the stream was disposed.
/// </exception>
/// <exception cref="IOException">
/// Thrown in case of any problems during reading.
/// </exception>
/// <param name="reader">Input stream reader.</param>
/// <param name="result">Read header or empty header.</param>
/// <returns>
/// True if program header was successfully read and false otherwise.
/// </returns>
public static bool TryRead(BinaryReader reader, out ProgramHeader result)
{
result = EmptyHeader;
if (!HeadersReadingUtils.IsEnoughBytes(reader, Size))
{
return(false);
}
var typeValue = reader.ReadUInt32();
var flags = reader.ReadUInt32();
var offset = reader.ReadUInt64();
var vaddr = reader.ReadUInt64();
var paddr = reader.ReadUInt64();
var filesz = reader.ReadUInt64();
var memsz = reader.ReadUInt64();
var align = reader.ReadUInt64();
if (!Enum.TryParse(typeValue.ToString(), out Type type) ||
!Enum.IsDefined(typeof(Type), type))
{
type = Type.Other;
}
result = new ProgramHeader(type, offset, vaddr, filesz);
return(true);
}
/// <summary>
/// Read all note sections until the end of stream and parse file indexes from them.
/// </summary>
/// <exception cref="ObjectDisposedException">
/// Thrown if the stream was disposed.
/// </exception>
/// <exception cref="IOException">
/// Thrown in case of any problems during reading.
/// </exception>
/// <param name="reader">Input stream reader.</param>
/// <param name="size">Expected note section size from program header.</param>
/// <returns>Core module files sections.</returns>
public static IEnumerable <FileSection> ReadModuleSections(BinaryReader reader, int size)
{
var result = new List <FileSection>();
foreach (NoteSection note in ReadNotes(reader, size))
{
if (note._name != Name.Core || note._type != Type.File)
{
continue;
}
var noteStream = new MemoryStream(note._data);
using (var noteReader = new BinaryReader(noteStream))
{
if (!HeadersReadingUtils.IsEnoughBytes(noteReader, MinNtFileIndexSize))
{
continue;
}
int count = (int)noteReader.ReadUInt64();
ulong pageSize = noteReader.ReadUInt64();
int locationsSize = FileLocationSize * count;
if (!HeadersReadingUtils.IsEnoughBytes(noteReader, locationsSize))
{
continue;
}
var starts = new ulong[count];
var ends = new ulong[count];
var offsets = new ulong[count];
for (int i = 0; i < count; i++)
{
starts[i] = noteReader.ReadUInt64();
ends[i] = noteReader.ReadUInt64();
offsets[i] = noteReader.ReadUInt64();
}
for (int i = 0; i < count; i++)
{
string path = ReadUtf8String(noteReader);
// We assume the build id lives in the first location.
if (offsets[i] == 0)
{
result.Add(new FileSection(path, starts[i], ends[i]));
}
}
}
}
return(result);
}
static List <NoteSection> ReadNotes(BinaryReader reader, int size)
{
var notes = new List <NoteSection>();
if (!HeadersReadingUtils.IsEnoughBytes(reader, Math.Max(size, MinNoteSize)))
{
return(notes);
}
while (reader.BaseStream.Position < reader.BaseStream.Length)
{
if (!HeadersReadingUtils.IsEnoughBytes(reader, MinNoteSize))
{
break;
}
int nameSize = reader.ReadInt32();
int descriptionSize = reader.ReadInt32();
uint typeValue = reader.ReadUInt32();
int namePadding = HeadersReadingUtils.GetInt32ValuePadding(nameSize);
int dataPadding = HeadersReadingUtils.GetInt32ValuePadding(descriptionSize);
int noteSize = nameSize + namePadding + descriptionSize + dataPadding;
if (!HeadersReadingUtils.IsEnoughBytes(reader, noteSize))
{
break;
}
byte[] nameBytes = reader.ReadBytes(nameSize);
reader.ReadBytes(namePadding);
byte[] desc = reader.ReadBytes(descriptionSize);
reader.ReadBytes(dataPadding);
string nameString = Encoding.UTF8.GetString(nameBytes, 0, nameBytes.Length - 1);
Type type;
switch (typeValue)
{
case NtFileType:
type = Type.File;
break;
case NtGnuBuildIdType:
type = Type.BuildId;
break;
default:
type = Type.Other;
break;
}
Name name;
switch (nameString)
{
case GnuName:
name = Name.Gnu;
break;
case CoreName:
name = Name.Core;
break;
default:
name = Name.Other;
break;
}
notes.Add(new NoteSection(type, name, desc));
}
return(notes);
}
/// <summary>
/// Try to read elf header.
/// </summary>
/// <exception cref="ObjectDisposedException">
/// Thrown if the stream was disposed.
/// </exception>
/// <exception cref="IOException">
/// Thrown in case of any problems during reading.
/// </exception>
/// <param name="reader">Input stream reader.</param>
/// <param name="result">Read header or empty header.</param>
/// <returns>
/// True if x64 elf header with little endianness and correct elf version was successfully
/// read and false otherwise.
/// </returns>
public static bool TryRead(BinaryReader reader, out ElfHeader result)
{
result = EmptyHeader;
if (!HeadersReadingUtils.IsEnoughBytes(reader, Size))
{
return(false);
}
var ei_magic = reader.ReadInt32();
var ei_bitness = reader.ReadByte();
var ei_endianness = reader.ReadByte();
var ei_version = reader.ReadByte();
var ei_abi = reader.ReadByte();
var ei_abi_version = reader.ReadByte();
var ei_padding = reader.ReadBytes(PaddingSize);
var e_type = reader.ReadInt16();
var e_machine = reader.ReadInt16();
var e_version = reader.ReadInt32();
var e_entry = reader.ReadInt64();
// Points to the start of the program header table.
var e_phoff = reader.ReadUInt64();
var e_shoff = reader.ReadUInt64();
var e_flags = reader.ReadInt32();
var e_ehsize = reader.ReadUInt16();
// Contains the size of a program header table entry.
var e_phentsize = reader.ReadUInt16();
// Contains the number of entries in the program header table.
var e_phnum = reader.ReadUInt16();
var e_shentsize = reader.ReadUInt16();
var e_shnum = reader.ReadUInt16();
var e_shstrndx = reader.ReadUInt16();
if (ei_magic != ElfMagicNumber)
{
Trace.WriteLine($"Invalid ELF magic {ElfMagicNumber} expected {ei_magic}.");
return(false);
}
if (ei_bitness != (byte)Bitness.x64)
{
Trace.WriteLine("Only 64-bit elf supported.");
return(false);
}
if (ei_endianness != (byte)Endianness.Little)
{
Trace.WriteLine("Only little endian supported.");
return(false);
}
if (ei_version != CurrentElfVersion)
{
Trace.WriteLine($"Invalid elf version: {ei_version} expected: " +
$"{CurrentElfVersion}.");
return(false);
}
result = new ElfHeader(e_phoff, e_phentsize, e_phnum, e_type == (byte)Type.Executable);
return(true);
}
