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.
    mfd.add_seals(&[
        memfd::FileSeal::SealShrink,
        memfd::FileSeal::SealGrow
    ])?;

    // 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 Aliases

• SealsHashSet
  An HashSet specialized on FileSeal.