Struct UdpStream

pub struct UdpStream<P>
where
    P: RuntimeProvider,
{ /* private fields */ }

A UDP stream of DNS binary packets

Implementations

impl<P> UdpStream<P>

where P: RuntimeProvider,

pub fn new( remote_addr: SocketAddr, bind_addr: Option<SocketAddr>, avoid_local_ports: Option<Arc<HashSet<u16>>>, os_port_selection: bool, provider: P, ) -> (Box<dyn Future<Output = Result<UdpStream<P>, Error>> + Send + Unpin>, BufDnsStreamHandle)

This method is intended for client connections, see Self::with_bound for a method better for straight listening. It is expected that the resolver wrapper will be responsible for creating and managing new UdpStreams such that each new client would have a random port (reduce chance of cache poisoning). This will return a randomly assigned local port, unless a nonzero port number is specified in bind_addr.

Arguments

• remote_addr - socket address for the remote connection (used to determine IPv4 or IPv6)
• bind_addr - optional local socket address to connect from (if a nonzero port number is specified, it will be used instead of randomly selecting a port)
• os_port_selection - Boolean parameter to specify whether to use the operating system’s standard UDP port selection logic instead of Hickory’s logic to securely select a random source port. We do not recommend using this option unless absolutely necessary, as the operating system may select ephemeral ports from a smaller range than Hickory, which can make response poisoning attacks easier to conduct. Some operating systems (notably, Windows) might display a user-prompt to allow a Hickory-specified port to be used, and setting this option will prevent those prompts from being displayed. If os_port_selection is true, avoid_local_udp_ports will be ignored.
• provider - async runtime provider, for I/O and timers

Return

A tuple of a Future of a Stream which will handle sending and receiving messages, and a handle which can be used to send messages into the stream.

impl<P> UdpStream<P>

where P: RuntimeProvider,

pub fn with_bound( socket: <P as RuntimeProvider>::Udp, remote_addr: SocketAddr, ) -> (UdpStream<P>, BufDnsStreamHandle)

Initialize the Stream with an already bound socket. Generally this should be only used for server listening sockets. See Self::new for a client oriented socket. Specifically, this requires there is already a bound socket, whereas new makes sure to randomize ports for additional cache poison prevention.

Arguments

• socket - an already bound UDP socket
• remote_addr - remote side of this connection

Return

A tuple of a Stream which will handle sending and receiving messages, and a handle which can be used to send messages into the stream.

Trait Implementations

impl<P> Stream for UdpStream<P>

where P: RuntimeProvider,

type Item = Result<SerialMessage, Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut UdpStream<P>>, cx: &mut Context<'_>, ) -> Poll<Option<<UdpStream<P> as Stream>::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.