smol-rs
/
async-net
mirror of https://github.com/smol-rs/async-net
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
async-net/src/udp.rs

663 lines
23 KiB
Rust
Raw Permalink Blame History

use std::io;
use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr};
#[cfg(unix)]
use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, OwnedFd, RawFd};
#[cfg(windows)]
use std::os::windows::io::{AsRawSocket, AsSocket, BorrowedSocket, OwnedSocket, RawSocket};
use std::sync::Arc;
use async_io::Async;
use crate::addr::AsyncToSocketAddrs;
/// A UDP socket.
///
/// After creating a [`UdpSocket`] by [`bind`][`UdpSocket::bind()`]ing it to a socket address, data
/// can be [sent to] and [received from] any other socket address.
///
/// Cloning a [`UdpSocket`] creates another handle to the same socket. The socket will be closed
/// when all handles to it are dropped.
///
/// Although UDP is a connectionless protocol, this implementation provides an interface to set an
/// address where data should be sent and received from. After setting a remote address with
/// [`connect()`][`UdpSocket::connect()`], data can be sent to and received from that address with
/// [`send()`][`UdpSocket::send()`] and [`recv()`][`UdpSocket::recv()`].
///
/// As stated in the User Datagram Protocol's specification in [IETF RFC 768], UDP is an unordered,
/// unreliable protocol. Refer to [`TcpListener`][`super::TcpListener`] and
/// [`TcpStream`][`super::TcpStream`] for TCP primitives.
///
/// [received from]: UdpSocket::recv_from()
/// [sent to]: UdpSocket::send_to()
/// [IETF RFC 768]: https://tools.ietf.org/html/rfc768
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:8080").await?;
/// let mut buf = vec![0u8; 20];
///
/// loop {
/// // Receive a single datagram message.
/// // If `buf` is too small to hold the entire message, it will be cut off.
/// let (n, addr) = socket.recv_from(&mut buf).await?;
///
/// // Send the message back to the same address that has sent it.
/// socket.send_to(&buf[..n], &addr).await?;
/// }
/// # std::io::Result::Ok(()) });
/// ```
#[derive(Clone, Debug)]
pub struct UdpSocket {
inner: Arc<Async<std::net::UdpSocket>>,
}
impl UdpSocket {
fn new(inner: Arc<Async<std::net::UdpSocket>>) -> UdpSocket {
UdpSocket { inner }
}
/// Creates a new [`UdpSocket`] bound to the given address.
///
/// Binding with a port number of 0 will request that the operating system assigns an available
/// port to this socket. The assigned port can be queried via the
/// [`local_addr()`][`UdpSocket::local_addr()`] method.
///
/// If `addr` yields multiple addresses, binding will be attempted with each of the addresses
/// until one succeeds and returns the socket. If none of the addresses succeed in creating a
/// socket, the error from the last attempt is returned.
///
/// # Examples
///
/// Create a UDP socket bound to `127.0.0.1:3400`:
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:3400").await?;
/// # std::io::Result::Ok(()) });
/// ```
///
/// Create a UDP socket bound to `127.0.0.1:3400`. If that address is unavailable, then try
/// binding to `127.0.0.1:3401`:
///
/// ```no_run
/// use async_net::{SocketAddr, UdpSocket};
///
/// # futures_lite::future::block_on(async {
/// let addrs = [
/// SocketAddr::from(([127, 0, 0, 1], 3400)),
/// SocketAddr::from(([127, 0, 0, 1], 3401)),
/// ];
/// let socket = UdpSocket::bind(&addrs[..]).await?;
/// # std::io::Result::Ok(()) });
/// ```
pub async fn bind<A: AsyncToSocketAddrs>(addr: A) -> io::Result<UdpSocket> {
let mut last_err = None;
for addr in addr.to_socket_addrs().await? {
match Async::<std::net::UdpSocket>::bind(addr) {
Ok(socket) => return Ok(UdpSocket::new(Arc::new(socket))),
Err(err) => last_err = Some(err),
}
}
Err(last_err.unwrap_or_else(|| {
io::Error::new(
io::ErrorKind::InvalidInput,
"could not bind to any of the addresses",
)
}))
}
/// Returns the local address this socket is bound to.
///
/// This can be useful, for example, when binding to port 0 to figure out which port was
/// actually bound.
///
/// # Examples
///
/// Bind to port 0 and then see which port was assigned by the operating system:
///
/// ```no_run
/// use async_net::{SocketAddr, UdpSocket};
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:0").await?;
/// println!("Bound to {}", socket.local_addr()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn local_addr(&self) -> io::Result<SocketAddr> {
self.inner.get_ref().local_addr()
}
/// Returns the remote address this socket is connected to.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.connect("192.168.0.1:41203").await?;
/// println!("Connected to {}", socket.peer_addr()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn peer_addr(&self) -> io::Result<SocketAddr> {
self.inner.get_ref().peer_addr()
}
/// Connects the UDP socket to an address.
///
/// When connected, methods [`send()`][`UdpSocket::send()`] and [`recv()`][`UdpSocket::recv()`]
/// will use the specified address for sending and receiving messages. Additionally, a filter
/// will be applied to [`recv_from()`][`UdpSocket::recv_from()`] so that it only receives
/// messages from that same address.
///
/// If `addr` yields multiple addresses, connecting will be attempted with each of the
/// addresses until the operating system accepts one. If none of the addresses are accepted,
/// the error from the last attempt is returned.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:3400").await?;
/// socket.connect("127.0.0.1:8080").await?;
/// # std::io::Result::Ok(()) });
/// ```
pub async fn connect<A: AsyncToSocketAddrs>(&self, addr: A) -> io::Result<()> {
let mut last_err = None;
for addr in addr.to_socket_addrs().await? {
match self.inner.get_ref().connect(addr) {
Ok(()) => return Ok(()),
Err(err) => last_err = Some(err),
}
}
Err(last_err.unwrap_or_else(|| {
io::Error::new(
io::ErrorKind::InvalidInput,
"could not connect to any of the addresses",
)
}))
}
/// Receives a single datagram message.
///
/// On success, returns the number of bytes received and the address message came from.
///
/// This method must be called with a valid byte buffer of sufficient size to hold a message.
/// If the received message is too long to fit into the buffer, it may be truncated.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
///
/// let mut buf = vec![0u8; 1024];
/// let (n, addr) = socket.recv_from(&mut buf).await?;
/// println!("Received {} bytes from {}", n, addr);
/// # std::io::Result::Ok(()) });
/// ```
pub async fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
self.inner.recv_from(buf).await
}
/// Receives a single datagram message without removing it from the queue.
///
/// On success, returns the number of bytes peeked and the address message came from.
///
/// This method must be called with a valid byte buffer of sufficient size to hold a message.
/// If the received message is too long to fit into the buffer, it may be truncated.
///
/// Successive calls return the same message. This is accomplished by passing `MSG_PEEK` as a
/// flag to the underlying `recvfrom` system call.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
///
/// let mut buf = vec![0u8; 1024];
/// let (n, addr) = socket.peek_from(&mut buf).await?;
/// println!("Peeked {} bytes from {}", n, addr);
/// # std::io::Result::Ok(()) });
/// ```
pub async fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
self.inner.get_ref().peek_from(buf)
}
/// Sends data to the given address.
///
/// On success, returns the number of bytes sent.
///
/// If `addr` yields multiple addresses, the message will only be sent to the first address.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.send_to(b"hello", "127.0.0.1:4242").await?;
/// # std::io::Result::Ok(()) });
/// ```
pub async fn send_to<A: AsyncToSocketAddrs>(&self, buf: &[u8], addr: A) -> io::Result<usize> {
let addr = match addr.to_socket_addrs().await?.next() {
Some(addr) => addr,
None => {
return Err(io::Error::new(
io::ErrorKind::InvalidInput,
"no addresses to send data to",
))
}
};
self.inner.send_to(buf, addr).await
}
/// Receives a single datagram message from the connected address.
///
/// On success, returns the number of bytes received.
///
/// This method must be called with a valid byte buffer of sufficient size to hold a message.
/// If the received message is too long to fit into the buffer, it may be truncated.
///
/// The [`connect()`][`UdpSocket::connect()`] method connects this socket to an address. This
/// method will fail if the socket is not connected.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.connect("127.0.0.1:8080").await?;
///
/// let mut buf = vec![0u8; 1024];
/// let n = socket.recv(&mut buf).await?;
/// println!("Received {} bytes", n);
/// # std::io::Result::Ok(()) });
/// ```
pub async fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.recv(buf).await
}
/// Receives a single datagram from the connected address without removing it from the queue.
///
/// On success, returns the number of bytes peeked.
///
/// This method must be called with a valid byte buffer of sufficient size to hold a message.
/// If the received message is too long to fit into the buffer, it may be truncated.
///
/// Successive calls return the same message. This is accomplished by passing `MSG_PEEK` as a
/// flag to the underlying `recv` system call.
///
/// The [`connect()`][`UdpSocket::connect()`] method connects this socket to an address. This
/// method will fail if the socket is not connected.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.connect("127.0.0.1:8080").await?;
///
/// let mut buf = vec![0u8; 1024];
/// let n = socket.peek(&mut buf).await?;
/// println!("Peeked {} bytes", n);
/// # std::io::Result::Ok(()) });
/// ```
pub async fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.peek(buf).await
}
/// Sends data to the connected address.
///
/// The [`connect()`][`UdpSocket::connect()`] method connects this socket to an address. This
/// method will fail if the socket is not connected.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.connect("127.0.0.1:8080").await?;
/// socket.send(b"hello").await?;
/// # std::io::Result::Ok(()) });
/// ```
pub async fn send(&self, buf: &[u8]) -> io::Result<usize> {
self.inner.send(buf).await
}
/// Gets the value of the `SO_BROADCAST` option for this socket.
///
/// If set to `true`, this socket is allowed to send packets to a broadcast address.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// println!("SO_BROADCAST is set to {}", socket.broadcast()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn broadcast(&self) -> io::Result<bool> {
self.inner.get_ref().broadcast()
}
/// Sets the value of the `SO_BROADCAST` option for this socket.
///
/// If set to `true`, this socket is allowed to send packets to a broadcast address.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.set_broadcast(true)?;
/// # std::io::Result::Ok(()) });
/// ```
pub fn set_broadcast(&self, broadcast: bool) -> io::Result<()> {
self.inner.get_ref().set_broadcast(broadcast)
}
/// Gets the value of the `IP_MULTICAST_LOOP` option for this socket.
///
/// If set to `true`, multicast packets will be looped back to the local socket.
///
/// Note that this option may not have any affect on IPv6 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// println!("IP_MULTICAST_LOOP is set to {}", socket.multicast_loop_v4()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn multicast_loop_v4(&self) -> io::Result<bool> {
self.inner.get_ref().multicast_loop_v4()
}
/// Sets the value of the `IP_MULTICAST_LOOP` option for this socket.
///
/// If set to `true`, multicast packets will be looped back to the local socket.
///
/// Note that this option may not have any affect on IPv6 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.set_multicast_loop_v4(true)?;
/// # std::io::Result::Ok(()) });
/// ```
pub fn set_multicast_loop_v4(&self, multicast_loop_v4: bool) -> io::Result<()> {
self.inner
.get_ref()
.set_multicast_loop_v4(multicast_loop_v4)
}
/// Gets the value of the `IP_MULTICAST_TTL` option for this socket.
///
/// Indicates the time-to-live value of outgoing multicast packets for this socket. The default
/// value is 1, which means that multicast packets don't leave the local network unless
/// explicitly requested.
///
/// Note that this option may not have any effect on IPv6 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// println!("IP_MULTICAST_TTL is set to {}", socket.multicast_loop_v4()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
self.inner.get_ref().multicast_ttl_v4()
}
/// Sets the value of the `IP_MULTICAST_TTL` option for this socket.
///
/// Indicates the time-to-live value of outgoing multicast packets for this socket. The default
/// value is 1, which means that multicast packets don't leave the local network unless
/// explicitly requested.
///
/// Note that this option may not have any effect on IPv6 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.set_multicast_ttl_v4(10)?;
/// # std::io::Result::Ok(()) });
/// ```
pub fn set_multicast_ttl_v4(&self, ttl: u32) -> io::Result<()> {
self.inner.get_ref().set_multicast_ttl_v4(ttl)
}
/// Gets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
///
/// Controls whether this socket sees the multicast packets it sends itself.
///
/// Note that this option may not have any effect on IPv4 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// println!("IPV6_MULTICAST_LOOP is set to {}", socket.multicast_loop_v6()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn multicast_loop_v6(&self) -> io::Result<bool> {
self.inner.get_ref().multicast_loop_v6()
}
/// Sets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
///
/// Controls whether this socket sees the multicast packets it sends itself.
///
/// Note that this option may not have any effect on IPv4 sockets.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.set_multicast_loop_v6(true)?;
/// # std::io::Result::Ok(()) });
/// ```
pub fn set_multicast_loop_v6(&self, multicast_loop_v6: bool) -> io::Result<()> {
self.inner
.get_ref()
.set_multicast_loop_v6(multicast_loop_v6)
}
/// Gets the value of the `IP_TTL` option for this socket.
///
/// This option configures the time-to-live field that is used in every packet sent from this
/// socket.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// println!("IP_TTL is set to {}", socket.ttl()?);
/// # std::io::Result::Ok(()) });
/// ```
pub fn ttl(&self) -> io::Result<u32> {
self.inner.get_ref().ttl()
}
/// Sets the value of the `IP_TTL` option for this socket.
///
/// This option configures the time-to-live field that is used in every packet sent from this
/// socket.
///
/// # Examples
///
/// ```no_run
/// use async_net::UdpSocket;
///
/// # futures_lite::future::block_on(async {
/// let socket = UdpSocket::bind("127.0.0.1:34254").await?;
/// socket.set_ttl(100)?;
/// # std::io::Result::Ok(()) });
/// ```
pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
self.inner.get_ref().set_ttl(ttl)
}
/// Executes an operation of the `IP_ADD_MEMBERSHIP` type.
///
/// This method specifies a new multicast group for this socket to join. Argument `multiaddr`
/// must be a valid multicast address, and `interface` is the address of the local interface
/// with which the system should join the multicast group. If it's equal to `INADDR_ANY` then
/// an appropriate interface is chosen by the system.
pub fn join_multicast_v4(&self, multiaddr: Ipv4Addr, interface: Ipv4Addr) -> io::Result<()> {
self.inner
.get_ref()
.join_multicast_v4(&multiaddr, &interface)
}
/// Executes an operation of the `IP_DROP_MEMBERSHIP` type.
///
/// This method leaves a multicast group. Argument `multiaddr` must be a valid multicast
/// address, and `interface` is the index of the interface to leave.
pub fn leave_multicast_v4(&self, multiaddr: Ipv4Addr, interface: Ipv4Addr) -> io::Result<()> {
self.inner
.get_ref()
.leave_multicast_v4(&multiaddr, &interface)
}
/// Executes an operation of the `IPV6_ADD_MEMBERSHIP` type.
///
/// This method specifies a new multicast group for this socket to join. Argument `multiaddr`
/// must be a valid multicast address, and `interface` is the index of the interface to join
/// (or 0 to indicate any interface).
pub fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> {
self.inner.get_ref().join_multicast_v6(multiaddr, interface)
}
/// Executes an operation of the `IPV6_DROP_MEMBERSHIP` type.
///
/// This method leaves a multicast group. Argument `multiaddr` must be a valid multicast
/// address, and `interface` is the index of the interface to leave.
pub fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> {
self.inner
.get_ref()
.leave_multicast_v6(multiaddr, interface)
}
}
impl From<Async<std::net::UdpSocket>> for UdpSocket {
fn from(socket: Async<std::net::UdpSocket>) -> UdpSocket {
UdpSocket::new(Arc::new(socket))
}
}
impl TryFrom<std::net::UdpSocket> for UdpSocket {
type Error = io::Error;
fn try_from(socket: std::net::UdpSocket) -> io::Result<UdpSocket> {
Ok(UdpSocket::new(Arc::new(Async::new(socket)?)))
}
}
impl From<UdpSocket> for Arc<Async<std::net::UdpSocket>> {
fn from(val: UdpSocket) -> Self {
val.inner
}
}
#[cfg(unix)]
impl AsRawFd for UdpSocket {
fn as_raw_fd(&self) -> RawFd {
self.inner.as_raw_fd()
}
}
#[cfg(unix)]
impl AsFd for UdpSocket {
fn as_fd(&self) -> BorrowedFd<'_> {
self.inner.get_ref().as_fd()
}
}
#[cfg(unix)]
impl TryFrom<OwnedFd> for UdpSocket {
type Error = io::Error;
fn try_from(value: OwnedFd) -> Result<Self, Self::Error> {
Self::try_from(std::net::UdpSocket::from(value))
}
}
#[cfg(windows)]
impl AsRawSocket for UdpSocket {
fn as_raw_socket(&self) -> RawSocket {
self.inner.as_raw_socket()
}
}
#[cfg(windows)]
impl AsSocket for UdpSocket {
fn as_socket(&self) -> BorrowedSocket<'_> {
self.inner.get_ref().as_socket()
}
}
#[cfg(windows)]
impl TryFrom<OwnedSocket> for UdpSocket {
type Error = io::Error;
fn try_from(value: OwnedSocket) -> Result<Self, Self::Error> {
Self::try_from(std::net::UdpSocket::from(value))
}
}
Reference in New Issue View Git Blame Copy Permalink