Crate memfd

A pure-Rust library to work with Linux memfd and seals.

It provides support for creating memfd objects on Linux and handling seals on them. This was first introduced in Linux kernel 3.17. For further details, see memfd_create(2) manpage.

use memfd;

fn new_sized_memfd() -> Result<memfd::Memfd, Box<dyn std::error::Error>> {
    // Create a sealable memfd.
    let opts = memfd::MemfdOptions::default().allow_sealing(true);
    let mfd = opts.create("sized-1K")?;

    // Resize to 1024B.
    mfd.as_file().set_len(1024)?;

    // Add seals to prevent further resizing.
    let mut seals = memfd::SealsHashSet::new();
    seals.insert(memfd::FileSeal::SealShrink);
    seals.insert(memfd::FileSeal::SealGrow);
    mfd.add_seals(&seals)?;

    // Prevent further sealing changes.
    mfd.add_seal(memfd::FileSeal::SealSeal)?;

    Ok(mfd)
}

Structs

Memfd

An anonymous volatile file, with sealing capabilities.

MemfdOptions

A Memfd builder, providing advanced options and flags for specifying its behavior.

Enums

Error

Enumeration of errors possible in this library

FileSeal

Seal that can be applied to a Memfd.

HugetlbSize

Page size for a hugetlb anonymous file.

Type Definitions

SealsHashSet

An HashSet specialized on FileSeal.