dlopen-rs

A high-performance, pure-Rust implementation of an ELF dynamic linker.

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dlopen-rs is a full-featured dynamic linker implemented entirely in Rust. It provides a set of Rust-friendly interfaces for manipulating dynamic libraries, as well as C-compatible interfaces consistent with libc behavior.

🚀 Key Features

• Pure Rust: Zero dependency on C runtime for core loading and linking logic.
• #![no_std] Support: Can be used in bare-metal environments, kernels, or embedded systems.
• LD_PRELOAD Compatible: Can replace libc's dlopen, dlsym, and dl_iterate_phdr without code modification.
• Modern API: Offers a safe and ergonomic Rust API for dynamic library management.

🛠 Usage

As a Rust Library

Add dlopen-rs to your Cargo.toml:

[dependencies]
dlopen-rs = "0.8.0"

As an LD_PRELOAD Replacement

You can use dlopen-rs to intercept standard library calls:

# 1. Compile the compatibility library
$ cargo build -r -p cdylib

# 2. Compile your application/example
$ cargo build -r -p dlopen-rs --example preload

# 3. Interpose libc implementations
$ RUST_LOG=trace LD_PRELOAD=./target/release/libdlopen.so ./target/release/examples/preload

📊 Architecture Support

Architecture	Load Support	Lazy Binding	Test Status
x86_64	✅	✅	✅ (CI)
aarch64	✅	✅	🛠️ (Manual)
riscv64	✅	✅	🛠️ (Manual)

💻 Example

use dlopen_rs::{ElfLibrary, OpenFlags, Result};

fn main() -> Result<()> {
    // 1. Load the library
    let lib = ElfLibrary::dlopen("./target/release/libexample.so", OpenFlags::RTLD_LAZY)?;

    // 2. Get and call a simple function: fn(i32, i32) -> i32
    let add = unsafe { lib.get::<fn(i32, i32) -> i32>("add")? };
    println!("add(1, 1) = {}", add(1, 1));

    Ok(())
}

⚙️ Feature Flags

Feature	Default	Description
use-syscall	❌	Uses direct syscalls to load libraries (useful for no_std).
version	❌	Enables support for ELF symbol versioning.
std	✅	Enables standard library integration. Disable for no_std environments.

⚖️ License

Licensed under the Apache License 2.0.

🤝 Contribution

Contributions are welcome! If you encounter issues or have ideas for performance improvements, please open an Issue or PR. For specific GDB-related debugging issues, please refer to TroubleshootingGdb.md.

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Minimum Supported Rust Version (MSRV): 1.93.0 or higher.