private unsafe void WriteSectionHeader64()
{
var hdr = new Elf64_Ehdr();
ObjectFile.CopyIdentTo(new Span <byte>(hdr.e_ident, EI_NIDENT));
_encoder.Encode(out hdr.e_type, (ushort)ObjectFile.FileType);
_encoder.Encode(out hdr.e_machine, ObjectFile.Arch.Value);
_encoder.Encode(out hdr.e_version, EV_CURRENT);
_encoder.Encode(out hdr.e_entry, ObjectFile.EntryPointAddress);
_encoder.Encode(out hdr.e_ehsize, Layout.SizeOfElfHeader);
_encoder.Encode(out hdr.e_flags, (uint)ObjectFile.Flags);
// program headers
_encoder.Encode(out hdr.e_phoff, Layout.OffsetOfProgramHeaderTable);
_encoder.Encode(out hdr.e_phentsize, Layout.SizeOfProgramHeaderEntry);
_encoder.Encode(out hdr.e_phnum, (ushort)ObjectFile.Segments.Count);
// entries for sections
_encoder.Encode(out hdr.e_shoff, Layout.OffsetOfSectionHeaderTable);
_encoder.Encode(out hdr.e_shentsize, (ushort)sizeof(Elf64_Shdr));
_encoder.Encode(out hdr.e_shnum, (ushort)ObjectFile.VisibleSectionCount);
_encoder.Encode(out hdr.e_shstrndx, (ushort)(ObjectFile.SectionHeaderStringTable?.SectionIndex ?? (ushort)0));
Write(hdr);
}
protected ELF64()
{
Header = new Elf64_Ehdr();
SectionHeader = null;
SectionName = null;
NameMaxLength = 0;
}
public ELF64(string filename, bool readSectionHeaders)
: this()
{
FileStream fs = File.Open(filename, FileMode.Open);
byte[] ehdrBytes = new byte[64];
fs.Read(ehdrBytes, 0, ehdrBytes.Length);
fs.Close();
if (!(ehdrBytes[(byte)EI.MagicNumber0] == 0x7F &&
ehdrBytes[(byte)EI.MagicNumber1] == 'E' &&
ehdrBytes[(byte)EI.MagicNumber2] == 'L' &&
ehdrBytes[(byte)EI.MagicNumber3] == 'F'))
{
throw new FormatException("It is not an ELF file.");
}
else if (ehdrBytes[(byte)EI.FileClass] == (byte)EC.ELF32)
{
throw new FormatException("It is an ELF32 file.");
}
else if (ehdrBytes[(byte)EI.FileClass] != (byte)EC.ELF64)
{
throw new FormatException("It is an invalid ELF class.");
}
ValueRead read = new ValueRead(ehdrBytes[(byte)EI.DataEncoding]);
Header = new Elf64_Ehdr(ehdrBytes, read);
SectionHeader = new Elf64_Shdr[Header.e_shnum];
SectionName = new string[Header.e_shnum];
if (readSectionHeaders && SectionHeader.Length != 0)
{
fs = File.Open(filename, FileMode.Open);
byte[] shdrBytes = new byte[Header.e_shnum * Header.e_shentsize];
fs.Position = (long)Header.e_shoff;
fs.Read(shdrBytes, 0, shdrBytes.Length);
fs.Close();
SectionHeader = new Elf64_Shdr[Header.e_shnum];
for (int i = 0; i < Header.e_shnum; i++)
{
SectionHeader[i] = new Elf64_Shdr(shdrBytes, (uint)(Header.e_shentsize * i), read);
SectionName[i] = "";
}
}
}
private static void GetEmbeddedModule64(ModuleReader reader, byte[] ident)
{
// Read the endiannes.
bool big = ident[(int)ElfIdent.EI_DATA] == (int)ElfData.ELFDATA2MSB;
// Read the header.
Elf64_Ehdr header = new Elf64_Ehdr();
header.Read(reader, big);
// Reject files without section names.
if (header.e_shstrndex == (int)ElfSectionNumber.SHN_UNDEF)
{
throw new ModuleException("Unsupported elfs without section names");
}
// Read the "section names" section.
reader.SetPosition(header.e_shoff + (ulong)header.e_shstrndex * header.e_shentsize);
Elf64_Shdr namesHeader = new Elf64_Shdr();
namesHeader.Read(reader, big);
// Reject files without real section names.
if (namesHeader.sh_size == 0)
{
throw new ModuleException("This elf doesn't have section names.");
}
// Read the name table.
byte[] nameTable;
reader.SetPosition(namesHeader.sh_offset);
reader.Read(out nameTable, (int)namesHeader.sh_size);
// Move to the section header table.
reader.SetPosition(header.e_shoff);
// Read the section until hit '.cbm'.
Elf64_Shdr sectionHeader = new Elf64_Shdr();
bool found = false;
StringBuilder builder = new StringBuilder();
for (int i = 0; i < header.e_shnum; ++i)
{
// Read the section header.
sectionHeader.Read(reader, big);
// Check the section name.
if (sectionHeader.sh_name >= nameTable.Length)
{
throw new ModuleException("Invalid section name.");
}
// Build the section name.
builder.Length = 0;
int pos = (int)sectionHeader.sh_name;
while (nameTable[pos] != 0)
{
builder.Append((char)nameTable[pos++]);
}
string sectionName = builder.ToString();
// Compare the section name.
if (sectionName == ".cbm")
{
found = true;
break;
}
// Skip the extra data.
reader.Skip(header.e_shentsize - Elf64_Shdr.Size);
}
// Make sure the section was found.
if (!found)
{
throw new ModuleException("The elf doesn't have a chela module.");
}
// Make sure the section type is PROGBITS.
if (sectionHeader.sh_type != (int)ElfSectionType.SHT_PROGBITS)
{
throw new ModuleException("The elf section that can have the module is not supported.");
}
// Move to the section offset.
reader.SetPosition(sectionHeader.sh_offset);
}
private static void GetEmbeddedModule64(ModuleReader reader, byte[] ident)
{
// Read the endiannes.
bool big = ident[(int)ElfIdent.EI_DATA] == (int)ElfData.ELFDATA2MSB;
// Read the header.
Elf64_Ehdr header = new Elf64_Ehdr();
header.Read(reader, big);
// Reject files without section names.
if(header.e_shstrndex == (int)ElfSectionNumber.SHN_UNDEF)
throw new ModuleException("Unsupported elfs without section names");
// Read the "section names" section.
reader.SetPosition(header.e_shoff + (ulong)header.e_shstrndex*header.e_shentsize);
Elf64_Shdr namesHeader = new Elf64_Shdr();
namesHeader.Read(reader, big);
// Reject files without real section names.
if(namesHeader.sh_size == 0)
throw new ModuleException("This elf doesn't have section names.");
// Read the name table.
byte[] nameTable;
reader.SetPosition(namesHeader.sh_offset);
reader.Read(out nameTable, (int)namesHeader.sh_size);
// Move to the section header table.
reader.SetPosition(header.e_shoff);
// Read the section until hit '.cbm'.
Elf64_Shdr sectionHeader = new Elf64_Shdr();
bool found = false;
StringBuilder builder = new StringBuilder();
for(int i = 0; i < header.e_shnum; ++i)
{
// Read the section header.
sectionHeader.Read(reader, big);
// Check the section name.
if(sectionHeader.sh_name >= nameTable.Length)
throw new ModuleException("Invalid section name.");
// Build the section name.
builder.Length = 0;
int pos = (int)sectionHeader.sh_name;
while(nameTable[pos] != 0)
builder.Append((char)nameTable[pos++]);
string sectionName = builder.ToString();
// Compare the section name.
if(sectionName == ".cbm")
{
found = true;
break;
}
// Skip the extra data.
reader.Skip(header.e_shentsize - Elf64_Shdr.Size);
}
// Make sure the section was found.
if(!found)
throw new ModuleException("The elf doesn't have a chela module.");
// Make sure the section type is PROGBITS.
if(sectionHeader.sh_type != (int)ElfSectionType.SHT_PROGBITS)
throw new ModuleException("The elf section that can have the module is not supported.");
// Move to the section offset.
reader.SetPosition(sectionHeader.sh_offset);
}
