Crate goblin

libgoblin

libgoblin is a cross-platform trifecta of binary parsing and loading fun. It supports:

• An ELF32/64 parser, and raw C structs
• A 32/64-bit, zero-copy, endian aware, Mach-o parser, and raw C structs
• A PE32/PE32+ (64-bit) parser, and raw C structs
• A Unix archive parser and loader

Goblin should require at least rustc 1.16, but is developed on stable.

Goblin primarily supports the following important use cases:

1. Core, std-free #[repr(C)] structs, tiny compile time, 32/64 (or both) at your leisure

2. Type punning. Define a function once on a type, but have it work on 32 or 64-bit variants - without really changing anything, and no macros! See examples/automagic.rs for a basic example.

3. std mode. This throws in read and write impls via Pread and Pwrite, reading from file, convenience allocations, extra methods, etc. This is for clients who can allocate and want to read binaries off disk.

4. Endian_fd. A truly terrible name :laughing: this is for binary analysis like in panopticon which needs to read binaries of foreign endianness, or as a basis for constructing cross platform foreign architecture binutils, e.g. cargo-sym and bingrep are simple examples of this, but the sky is the limit.

Example

use goblin::{error, Object};
use std::path::Path;
use std::env;
use std::fs::File;
use std::io::Read;

fn run () -> error::Result<()> {
    for (i, arg) in env::args().enumerate() {
        if i == 1 {
            let path = Path::new(arg.as_str());
            let mut fd = File::open(path)?;
            let mut buffer = Vec::new();
            fd.read_to_end(&mut buffer)?;
            match Object::parse(&buffer)? {
                Object::Elf(elf) => {
                    println!("elf: {:#?}", &elf);
                },
                Object::PE(pe) => {
                    println!("pe: {:#?}", &pe);
                },
                Object::Mach(mach) => {
                    println!("mach: {:#?}", &mach);
                },
                Object::Archive(archive) => {
                    println!("archive: {:#?}", &archive);
                },
                Object::Unknown(magic) => { println!("unknown magic: {:#x}", magic) }
            }
        }
    }
    Ok(())
}

Feature Usage

libgoblin is engineered to be tailored towards very different use-case scenarios, for example:

• a no-std mode; just simply set default features to false
• a endian aware parsing and reading
• for binary loaders which don’t require this, simply use elf32 and elf64 (and std of course)

For example, if you are writing a 64-bit kernel, or just want a barebones C-like header interface which defines the structures, just select elf64, --cfg feature="elf64", which will compile without std.

Similarly, if you want to use host endianness loading via the various from_fd methods, --cfg feature="std", which will not use the byteorder extern crate, and read the bytes from disk in the endianness of the host machine.

If you want endian aware reading, and you don’t use default, then you need to opt in as normal via endian_fd

Modules

archive

Implements a simple parser and extractor for a Unix Archive.

container

Binary container size information and byte-order context

elf

The generic ELF module, which gives access to ELF constants and other helper functions, which are independent of ELF bithood. Also defines an Elf struct which implements a unified parser that returns a wrapped Elf64 or Elf32 binary.

elf32

The ELF 32-bit struct definitions and associated values, re-exported for easy “type-punning”

elf64

The ELF 64-bit struct definitions and associated values, re-exported for easy “type-punning”

error

A custom Goblin error

mach

The Mach-o, mostly zero-copy, binary format parser and raw struct definitions

pe

A PE32 and PE32+ parser

strtab

A byte-offset based string table. Commonly used in ELF binaries, Unix archives, and even PE binaries.

Structs

HintData

Information obtained from a peek Hint

Enums

Hint

A hint at the underlying binary format for 16 bytes of arbitrary data

Object

A parseable object that goblin understands

Functions

peek

Peeks at the underlying Read object. Requires the underlying bytes to have at least 16 byte length. Resets the seek to Start after reading.

peek_bytes

Peeks at bytes, and returns a Hint