embassy/embassy-net/src/dns.rs
2023-06-06 17:58:45 +02:00

108 lines
3.2 KiB
Rust

//! DNS client compatible with the `embedded-nal-async` traits.
//!
//! This exists only for compatibility with crates that use `embedded-nal-async`.
//! Prefer using [`Stack::dns_query`](crate::Stack::dns_query) directly if you're
//! not using `embedded-nal-async`.
use heapless::Vec;
pub use smoltcp::socket::dns::{DnsQuery, Socket};
pub(crate) use smoltcp::socket::dns::{GetQueryResultError, StartQueryError};
pub use smoltcp::wire::{DnsQueryType, IpAddress};
use crate::{Driver, Stack};
/// Errors returned by DnsSocket.
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Error {
/// Invalid name
InvalidName,
/// Name too long
NameTooLong,
/// Name lookup failed
Failed,
}
impl From<GetQueryResultError> for Error {
fn from(_: GetQueryResultError) -> Self {
Self::Failed
}
}
impl From<StartQueryError> for Error {
fn from(e: StartQueryError) -> Self {
match e {
StartQueryError::NoFreeSlot => Self::Failed,
StartQueryError::InvalidName => Self::InvalidName,
StartQueryError::NameTooLong => Self::NameTooLong,
}
}
}
/// DNS client compatible with the `embedded-nal-async` traits.
///
/// This exists only for compatibility with crates that use `embedded-nal-async`.
/// Prefer using [`Stack::dns_query`](crate::Stack::dns_query) directly if you're
/// not using `embedded-nal-async`.
pub struct DnsSocket<'a, D>
where
D: Driver + 'static,
{
stack: &'a Stack<D>,
}
impl<'a, D> DnsSocket<'a, D>
where
D: Driver + 'static,
{
/// Create a new DNS socket using the provided stack.
///
/// NOTE: If using DHCP, make sure it has reconfigured the stack to ensure the DNS servers are updated.
pub fn new(stack: &'a Stack<D>) -> Self {
Self { stack }
}
/// Make a query for a given name and return the corresponding IP addresses.
pub async fn query(&self, name: &str, qtype: DnsQueryType) -> Result<Vec<IpAddress, 1>, Error> {
self.stack.dns_query(name, qtype).await
}
}
#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
impl<'a, D> embedded_nal_async::Dns for DnsSocket<'a, D>
where
D: Driver + 'static,
{
type Error = Error;
async fn get_host_by_name(
&self,
host: &str,
addr_type: embedded_nal_async::AddrType,
) -> Result<embedded_nal_async::IpAddr, Self::Error> {
use embedded_nal_async::{AddrType, IpAddr};
let qtype = match addr_type {
AddrType::IPv6 => DnsQueryType::Aaaa,
_ => DnsQueryType::A,
};
let addrs = self.query(host, qtype).await?;
if let Some(first) = addrs.get(0) {
Ok(match first {
#[cfg(feature = "proto-ipv4")]
IpAddress::Ipv4(addr) => IpAddr::V4(addr.0.into()),
#[cfg(feature = "proto-ipv6")]
IpAddress::Ipv6(addr) => IpAddr::V6(addr.0.into()),
})
} else {
Err(Error::Failed)
}
}
async fn get_host_by_address(
&self,
_addr: embedded_nal_async::IpAddr,
) -> Result<heapless::String<256>, Self::Error> {
todo!()
}
}