Simple Rust SNTP client

This crate provides a method for sending requests to NTP servers and process responses, extracting received timestamp.

Supported SNTP protocol versions:

• SNTPv4

Documentation

https://docs.rs/sntpc

Installation

This crate works with Cargo and is on crates.io. Add it to your Cargo.toml like so:

[dependencies]
sntpc = "0.3.4"

By calling the get_time() method and providing a proper NTP pool or server you should get a valid synchronization timestamp:

use sntpc::{Error, NtpContext, NtpTimestampGenerator, NtpUdpSocket, Result};
use std::net::{SocketAddr, ToSocketAddrs, UdpSocket};
use std::time::Duration;

#[derive(Copy, Clone, Default)]
struct StdTimestampGen {
    duration: Duration,
}

impl NtpTimestampGenerator for StdTimestampGen {
    fn init(&mut self) {
        self.duration = std::time::SystemTime::now()
            .duration_since(std::time::SystemTime::UNIX_EPOCH)
            .unwrap();
    }
    fn timestamp_sec(&self) -> u64 {
        self.duration.as_secs()
    }
    fn timestamp_subsec_micros(&self) -> u32 {
        self.duration.subsec_micros()
    }
}

#[derive(Debug)]
struct UdpSocketWrapper(UdpSocket);

impl NtpUdpSocket for UdpSocketWrapper {
    fn send_to<T: ToSocketAddrs>(
        &self,
        buf: &[u8],
        addr: T,
    ) -> Result<usize> {
        match self.0.send_to(buf, addr) {
            Ok(usize) => Ok(usize),
            Err(_) => Err(Error::Network),
        }
    }
    fn recv_from(&self, buf: &mut [u8]) -> Result<(usize, SocketAddr)> {
        match self.0.recv_from(buf) {
            Ok((size, addr)) => Ok((size, addr)),
            Err(_) => Err(Error::Network),
        }
    }
}
fn main() {
    let socket =
        UdpSocket::bind("0.0.0.0:0").expect("Unable to create UDP socket");
    socket
       .set_read_timeout(Some(Duration::from_secs(2)))
       .expect("Unable to set UDP socket read timeout");
    let sock_wrapper = UdpSocketWrapper(socket);
    let ntp_context = NtpContext::new(StdTimestampGen::default());
    let result =
        sntpc::get_time("time.google.com:123", sock_wrapper, ntp_context);

    match result {
       Ok(time) => {
           let microseconds = time.sec_fraction() as u64 * 1_000_000u64 / u32::MAX as u64;
           println!("Got time: {}.{}", time.sec(), microseconds);
       }
       Err(err) => println!("Err: {:?}", err),
    }
 }

no_std support

Currently there are basic no_std support available, thanks no-std-net crate. There is an example available on how to use smoltcp stack and that should provide general idea on how to bootstrap no_std networking and timestamping tools for sntpc library usage

Examples

You can find several examples that shows how to use the library in details under [examples/] folder. Currently, there are examples that show:

• usage of SNTP library in std environment
• usage of SNTP library with smoltcp TCP/IP stack. Some std dependencies required only due to smoltcp available interfaces

Contribution

Contributions are always welcome! If you have an idea, it's best to float it by me before working on it to ensure no effort is wasted. If there's already an open issue for it, knock yourself out. See the contributing section for additional details

License

This project is licensed under:

• The 3-Clause BSD License

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in time by you, as defined in the 3-Clause BSD license, shall be licensed as above, without any additional terms or conditions.