NTPD-rs

NTPD-rs is an implementation of NTP completely written in Rust, with a focus on exposing a minimal attack surface. The project is currently in an early stage, and is not yet suitable for daily use. However, you can try it out if you are comfortable with running pre-release software.

Quick start

Currently, NTPD-rs only supports Linux-based operating systems. Our current testing only targets Linux kernels after version 5.0.0, older kernels may work but this is not guaranteed.

NTPD-rs is written in rust, and requires cargo 1.60.0 at a minimum to be built. We strongly recommend using rustup to install a rust toolchain, because the version provided by system package managers tends to be out of date.

To build NTPD-rs run

cargo build --release

This produces a binary ntp-daemon in the target/release folder, which is the main NTP daemon.

Before running the NTPD-rs daemon, make sure that no other NTP daemons are running. E.g. when chrony is running

systemctl stop chronyd

The NTPD-rs daemon requires elevated permissions to change the system clock. It can be tested against a server in the NTP pool

sudo ./target/release/ntp-daemon -p pool.ntp.org

After a few minutes you should start to see messages indicating the offset of your machine from the server. A complete description of how the daemon can be configured can be found in the configuration documentation

Naming

We are currently looking for a better name for this project. Suggestions for this are welcome.

Package substructure

Currently, the code is split up into five separate crates:

ntp-proto contains the packet parsing and the algorithms needed for clock selection, filtering and steering.
ntp-daemon contains the main NTP daemon, and deals with orchestrating the networking and configuration.
test-binaries contains a number of simple NTP servers that can be used for testing (see below).
ntp-os-clock contains the unsafe code needed to interface with system clocks.
ntp-udp contains the unsafe code needed to deal with timestamping on the network layer.

All unsafe code is contained within the ntp-os-clock and ntp-udp packages, which are kept as small as possible. All interfaces exposed by these crates should be safe. For a more detailed description of how NTPD-rs is structured, see the development documentation.

Test Binaries

This crate contains extremely limited NTP servers for testing purposes

demobilize-server always sends the DENY kiss code, the client must demobilize this association
rate-limit-server forces an increase of the poll interval to 32 seconds

Minimum supported rust version

We try to keep NTPD-rs working on at least the latest stable, beta and nightly rust compiler. Beyond this, we keep track of the current minimum rust version needed to compile our code for purposes of documentation. However, right now we do not have a policy guaranteeing a minimum amount of time we will support a stable rust release beyond the 6 weeks during which it is the latest stable version.