#![deny(unsafe_op_in_unsafe_fn)]
#[cfg(all(test, not(any(target_os = "emscripten", target_os = "xous"))))]
mod tests;
use crate::fmt;
use crate::io::prelude::*;
use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
use crate::iter::FusedIterator;
use crate:🥅:{Shutdown, SocketAddr, ToSocketAddrs};
use crate::sys_common::{net as net_imp, AsInner, FromInner, IntoInner};
use crate::time::Duration;
/// A TCP stream between a local and a remote socket.
///
/// After creating a `TcpStream` by either [`connect`]ing to a remote host or
/// [`accept`]ing a connection on a [`TcpListener`], data can be transmitted
/// by [reading] and [writing] to it.
///
/// The connection will be closed when the value is dropped. The reading and writing
/// portions of the connection can also be shut down individually with the [`shutdown`]
/// method.
///
/// The Transmission Control Protocol is specified in [IETF RFC 793].
///
/// [`accept`]: TcpListener::accept
/// [`connect`]: TcpStream::connect
/// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
/// [reading]: Read
/// [`shutdown`]: TcpStream::shutdown
/// [writing]: Write
///
/// # Examples
///
/// ```no_run
/// use std::io::prelude::*;
/// use std:🥅:TcpStream;
///
/// fn main() -> std::io::Result<()> {
/// let mut stream = TcpStream::connect("127.0.0.1:34254")?;
///
/// stream.write(&[1])?;
/// stream.read(&mut [0; 128])?;
/// Ok(())
/// } // the stream is closed here
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub struct TcpStream(net_imp::TcpStream);
/// A TCP socket server, listening for connections.
///
/// After creating a `TcpListener` by [`bind`]ing it to a socket address, it listens
/// for incoming TCP connections. These can be accepted by calling [`accept`] or by
/// iterating over the [`Incoming`] iterator returned by [`incoming`][`TcpListener::incoming`].
///
/// The socket will be closed when the value is dropped.
///
/// The Transmission Control Protocol is specified in [IETF RFC 793].
///
/// [`accept`]: TcpListener::accept
/// [`bind`]: TcpListener::bind
/// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{TcpListener, TcpStream};
///
/// fn handle_client(stream: TcpStream) {
/// // ...
/// }
///
/// fn main() -> std::io::Result<()> {
/// let listener = TcpListener::bind("127.0.0.1:80")?;
///
/// // accept connections and process them serially
/// for stream in listener.incoming() {
/// handle_client(stream?);
/// }
/// Ok(())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub struct TcpListener(net_imp::TcpListener);
/// An iterator that infinitely [`accept`]s connections on a [`TcpListener`].
///
/// This `struct` is created by the [`TcpListener::incoming`] method.
/// See its documentation for more.
///
/// [`accept`]: TcpListener::accept
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Debug)]
pub struct Incoming<'a> {
listener: &'a TcpListener,
}
/// An iterator that infinitely [`accept`]s connections on a [`TcpListener`].
///
/// This `struct` is created by the [`TcpListener::into_incoming`] method.
/// See its documentation for more.
///
/// [`accept`]: TcpListener::accept
#[derive(Debug)]
#[unstable(feature = "tcplistener_into_incoming", issue = "88373")]
pub struct IntoIncoming {
listener: TcpListener,
}
impl TcpStream {
/// Opens a TCP connection to a remote host.
///
/// `addr` is an address of the remote host. Anything which implements
/// [`ToSocketAddrs`] trait can be supplied for the address; see this trait
/// documentation for concrete examples.
///
/// If `addr` yields multiple addresses, `connect` will be attempted with
/// each of the addresses until a connection is successful. If none of
/// the addresses result in a successful connection, the error returned from
/// the last connection attempt (the last address) is returned.
///
/// # Examples
///
/// Open a TCP connection to `127.0.0.1:8080`:
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// if let Ok(stream) = TcpStream::connect("127.0.0.1:8080") {
/// println!("Connected to the server!");
/// } else {
/// println!("Couldn't connect to server...");
/// }
/// ```
///
/// Open a TCP connection to `127.0.0.1:8080`. If the connection fails, open
/// a TCP connection to `127.0.0.1:8081`:
///
/// ```no_run
/// use std:🥅:{SocketAddr, TcpStream};
///
/// let addrs = [
/// SocketAddr::from(([127, 0, 0, 1], 8080)),
/// SocketAddr::from(([127, 0, 0, 1], 8081)),
/// ];
/// if let Ok(stream) = TcpStream::connect(&addrs[..]) {
/// println!("Connected to the server!");
/// } else {
/// println!("Couldn't connect to server...");
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn connect<A: ToSocketAddrs>(addr: A) -> io::Result<TcpStream> {
super::each_addr(addr, net_imp::TcpStream::connect).map(TcpStream)
}
/// Opens a TCP connection to a remote host with a timeout.
///
/// Unlike `connect`, `connect_timeout` takes a single [`SocketAddr`] since
/// timeout must be applied to individual addresses.
///
/// It is an error to pass a zero `Duration` to this function.
///
/// Unlike other methods on `TcpStream`, this does not correspond to a
/// single system call. It instead calls `connect` in nonblocking mode and
/// then uses an OS-specific mechanism to await the completion of the
/// connection request.
#[stable(feature = "tcpstream_connect_timeout", since = "1.21.0")]
pub fn connect_timeout(addr: &SocketAddr, timeout: Duration) -> io::Result<TcpStream> {
net_imp::TcpStream::connect_timeout(addr, timeout).map(TcpStream)
}
/// Returns the socket address of the remote peer of this TCP connection.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{Ipv4Addr, SocketAddr, SocketAddrV4, TcpStream};
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// assert_eq!(stream.peer_addr().unwrap(),
/// SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn peer_addr(&self) -> io::Result<SocketAddr> {
self.0.peer_addr()
}
/// Returns the socket address of the local half of this TCP connection.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{IpAddr, Ipv4Addr, TcpStream};
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// assert_eq!(stream.local_addr().unwrap().ip(),
/// IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn local_addr(&self) -> io::Result<SocketAddr> {
self.0.socket_addr()
}
/// Shuts down the read, write, or both halves of this connection.
///
/// This function will cause all pending and future I/O on the specified
/// portions to return immediately with an appropriate value (see the
/// documentation of [`Shutdown`]).
///
/// # Platform-specific behavior
///
/// Calling this function multiple times may result in different behavior,
/// depending on the operating system. On Linux, the second call will
/// return `Ok(())`, but on macOS, it will return `ErrorKind::NotConnected`.
/// This may change in the future.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{Shutdown, TcpStream};
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.shutdown(Shutdown::Both).expect("shutdown call failed");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
self.0.shutdown(how)
}
/// Creates a new independently owned handle to the underlying socket.
///
/// The returned `TcpStream` is a reference to the same stream that this
/// object references. Both handles will read and write the same stream of
/// data, and options set on one stream will be propagated to the other
/// stream.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// let stream_clone = stream.try_clone().expect("clone failed...");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn try_clone(&self) -> io::Result<TcpStream> {
self.0.duplicate().map(TcpStream)
}
/// Sets the read timeout to the timeout specified.
///
/// If the value specified is [`None`], then [`read`] calls will block
/// indefinitely. An [`Err`] is returned if the zero [`Duration`] is
/// passed to this method.
///
/// # Platform-specific behavior
///
/// Platforms may return a different error code whenever a read times out as
/// a result of setting this option. For example Unix typically returns an
/// error of the kind [`WouldBlock`], but Windows may return [`TimedOut`].
///
/// [`read`]: Read::read
/// [`WouldBlock`]: io::ErrorKind::WouldBlock
/// [`TimedOut`]: io::ErrorKind::TimedOut
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_read_timeout(None).expect("set_read_timeout call failed");
/// ```
///
/// An [`Err`] is returned if the zero [`Duration`] is passed to this
/// method:
///
/// ```no_run
/// use std::io;
/// use std:🥅:TcpStream;
/// use std::time::Duration;
///
/// let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
/// let result = stream.set_read_timeout(Some(Duration::new(0, 0)));
/// let err = result.unwrap_err();
/// assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
/// ```
#[stable(feature = "socket_timeout", since = "1.4.0")]
pub fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
self.0.set_read_timeout(dur)
}
/// Sets the write timeout to the timeout specified.
///
/// If the value specified is [`None`], then [`write`] calls will block
/// indefinitely. An [`Err`] is returned if the zero [`Duration`] is
/// passed to this method.
///
/// # Platform-specific behavior
///
/// Platforms may return a different error code whenever a write times out
/// as a result of setting this option. For example Unix typically returns
/// an error of the kind [`WouldBlock`], but Windows may return [`TimedOut`].
///
/// [`write`]: Write::write
/// [`WouldBlock`]: io::ErrorKind::WouldBlock
/// [`TimedOut`]: io::ErrorKind::TimedOut
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_write_timeout(None).expect("set_write_timeout call failed");
/// ```
///
/// An [`Err`] is returned if the zero [`Duration`] is passed to this
/// method:
///
/// ```no_run
/// use std::io;
/// use std:🥅:TcpStream;
/// use std::time::Duration;
///
/// let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
/// let result = stream.set_write_timeout(Some(Duration::new(0, 0)));
/// let err = result.unwrap_err();
/// assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
/// ```
#[stable(feature = "socket_timeout", since = "1.4.0")]
pub fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
self.0.set_write_timeout(dur)
}
/// Returns the read timeout of this socket.
///
/// If the timeout is [`None`], then [`read`] calls will block indefinitely.
///
/// # Platform-specific behavior
///
/// Some platforms do not provide access to the current timeout.
///
/// [`read`]: Read::read
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_read_timeout(None).expect("set_read_timeout call failed");
/// assert_eq!(stream.read_timeout().unwrap(), None);
/// ```
#[stable(feature = "socket_timeout", since = "1.4.0")]
pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
self.0.read_timeout()
}
/// Returns the write timeout of this socket.
///
/// If the timeout is [`None`], then [`write`] calls will block indefinitely.
///
/// # Platform-specific behavior
///
/// Some platforms do not provide access to the current timeout.
///
/// [`write`]: Write::write
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_write_timeout(None).expect("set_write_timeout call failed");
/// assert_eq!(stream.write_timeout().unwrap(), None);
/// ```
#[stable(feature = "socket_timeout", since = "1.4.0")]
pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
self.0.write_timeout()
}
/// Receives data on the socket from the remote address to which it is
/// connected, without removing that data from the queue. On success,
/// returns the number of bytes peeked.
///
/// Successive calls return the same data. This is accomplished by passing
/// `MSG_PEEK` as a flag to the underlying `recv` system call.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8000")
/// .expect("Couldn't connect to the server...");
/// let mut buf = [0; 10];
/// let len = stream.peek(&mut buf).expect("peek failed");
/// ```
#[stable(feature = "peek", since = "1.18.0")]
pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
self.0.peek(buf)
}
/// Sets the value of the `SO_LINGER` option on this socket.
///
/// This value controls how the socket is closed when data remains
/// to be sent. If `SO_LINGER` is set, the socket will remain open
/// for the specified duration as the system attempts to send pending data.
/// Otherwise, the system may close the socket immediately, or wait for a
/// default timeout.
///
/// # Examples
///
/// ```no_run
/// #![feature(tcp_linger)]
///
/// use std:🥅:TcpStream;
/// use std::time::Duration;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
/// ```
#[unstable(feature = "tcp_linger", issue = "88494")]
pub fn set_linger(&self, linger: Option<Duration>) -> io::Result<()> {
self.0.set_linger(linger)
}
/// Gets the value of the `SO_LINGER` option on this socket.
///
/// For more information about this option, see [`TcpStream::set_linger`].
///
/// # Examples
///
/// ```no_run
/// #![feature(tcp_linger)]
///
/// use std:🥅:TcpStream;
/// use std::time::Duration;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
/// assert_eq!(stream.linger().unwrap(), Some(Duration::from_secs(0)));
/// ```
#[unstable(feature = "tcp_linger", issue = "88494")]
pub fn linger(&self) -> io::Result<Option<Duration>> {
self.0.linger()
}
/// Sets the value of the `TCP_NODELAY` option on this socket.
///
/// If set, this option disables the Nagle algorithm. This means that
/// segments are always sent as soon as possible, even if there is only a
/// small amount of data. When not set, data is buffered until there is a
/// sufficient amount to send out, thereby avoiding the frequent sending of
/// small packets.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_nodelay(true).expect("set_nodelay call failed");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
self.0.set_nodelay(nodelay)
}
/// Gets the value of the `TCP_NODELAY` option on this socket.
///
/// For more information about this option, see [`TcpStream::set_nodelay`].
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_nodelay(true).expect("set_nodelay call failed");
/// assert_eq!(stream.nodelay().unwrap_or(false), true);
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn nodelay(&self) -> io::Result<bool> {
self.0.nodelay()
}
/// Sets the value for the `IP_TTL` option on this socket.
///
/// This value sets the time-to-live field that is used in every packet sent
/// from this socket.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_ttl(100).expect("set_ttl call failed");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
self.0.set_ttl(ttl)
}
/// Gets the value of the `IP_TTL` option for this socket.
///
/// For more information about this option, see [`TcpStream::set_ttl`].
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.set_ttl(100).expect("set_ttl call failed");
/// assert_eq!(stream.ttl().unwrap_or(0), 100);
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn ttl(&self) -> io::Result<u32> {
self.0.ttl()
}
/// Gets the value of the `SO_ERROR` option on this socket.
///
/// This will retrieve the stored error in the underlying socket, clearing
/// the field in the process. This can be useful for checking errors between
/// calls.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpStream;
///
/// let stream = TcpStream::connect("127.0.0.1:8080")
/// .expect("Couldn't connect to the server...");
/// stream.take_error().expect("No error was expected...");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn take_error(&self) -> io::Result<Option<io::Error>> {
self.0.take_error()
}
/// Moves this TCP stream into or out of nonblocking mode.
///
/// This will result in `read`, `write`, `recv` and `send` operations
/// becoming nonblocking, i.e., immediately returning from their calls.
/// If the IO operation is successful, `Ok` is returned and no further
/// action is required. If the IO operation could not be completed and needs
/// to be retried, an error with kind [`io::ErrorKind::WouldBlock`] is
/// returned.
///
/// On Unix platforms, calling this method corresponds to calling `fcntl`
/// `FIONBIO`. On Windows calling this method corresponds to calling
/// `ioctlsocket` `FIONBIO`.
///
/// # Examples
///
/// Reading bytes from a TCP stream in non-blocking mode:
///
/// ```no_run
/// use std::io::{self, Read};
/// use std:🥅:TcpStream;
///
/// let mut stream = TcpStream::connect("127.0.0.1:7878")
/// .expect("Couldn't connect to the server...");
/// stream.set_nonblocking(true).expect("set_nonblocking call failed");
///
/// # fn wait_for_fd() { unimplemented!() }
/// let mut buf = vec![];
/// loop {
/// match stream.read_to_end(&mut buf) {
/// Ok(_) => break,
/// Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
/// // wait until network socket is ready, typically implemented
/// // via platform-specific APIs such as epoll or IOCP
/// wait_for_fd();
/// }
/// Err(e) => panic!("encountered IO error: {e}"),
/// };
/// };
/// println!("bytes: {buf:?}");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
self.0.set_nonblocking(nonblocking)
}
}
// In addition to the `impl`s here, `TcpStream` also has `impl`s for
// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
// `AsSocket`/`From<OwnedSocket>`/`Into<OwnedSocket>` and
// `AsRawSocket`/`IntoRawSocket`/`FromRawSocket` on Windows.
#[stable(feature = "rust1", since = "1.0.0")]
impl Read for TcpStream {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
self.0.read_buf(buf)
}
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.0.read_vectored(bufs)
}
#[inline]
fn is_read_vectored(&self) -> bool {
self.0.is_read_vectored()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Write for TcpStream {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.0.write(buf)
}
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.0.write_vectored(bufs)
}
#[inline]
fn is_write_vectored(&self) -> bool {
self.0.is_write_vectored()
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Read for &TcpStream {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
self.0.read_buf(buf)
}
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.0.read_vectored(bufs)
}
#[inline]
fn is_read_vectored(&self) -> bool {
self.0.is_read_vectored()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Write for &TcpStream {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.0.write(buf)
}
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.0.write_vectored(bufs)
}
#[inline]
fn is_write_vectored(&self) -> bool {
self.0.is_write_vectored()
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
impl AsInner<net_imp::TcpStream> for TcpStream {
#[inline]
fn as_inner(&self) -> &net_imp::TcpStream {
&self.0
}
}
impl FromInner<net_imp::TcpStream> for TcpStream {
fn from_inner(inner: net_imp::TcpStream) -> TcpStream {
TcpStream(inner)
}
}
impl IntoInner<net_imp::TcpStream> for TcpStream {
fn into_inner(self) -> net_imp::TcpStream {
self.0
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for TcpStream {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl TcpListener {
/// Creates a new `TcpListener` which will be bound to the specified
/// address.
///
/// The returned listener is ready for accepting connections.
///
/// Binding with a port number of 0 will request that the OS assigns a port
/// to this listener. The port allocated can be queried via the
/// [`TcpListener::local_addr`] method.
///
/// The address type can be any implementor of [`ToSocketAddrs`] trait. See
/// its documentation for concrete examples.
///
/// If `addr` yields multiple addresses, `bind` will be attempted with
/// each of the addresses until one succeeds and returns the listener. If
/// none of the addresses succeed in creating a listener, the error returned
/// from the last attempt (the last address) is returned.
///
/// # Examples
///
/// Creates a TCP listener bound to `127.0.0.1:80`:
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
/// ```
///
/// Creates a TCP listener bound to `127.0.0.1:80`. If that fails, create a
/// TCP listener bound to `127.0.0.1:443`:
///
/// ```no_run
/// use std:🥅:{SocketAddr, TcpListener};
///
/// let addrs = [
/// SocketAddr::from(([127, 0, 0, 1], 80)),
/// SocketAddr::from(([127, 0, 0, 1], 443)),
/// ];
/// let listener = TcpListener::bind(&addrs[..]).unwrap();
/// ```
///
/// Creates a TCP listener bound to a port assigned by the operating system
/// at `127.0.0.1`.
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let socket = TcpListener::bind("127.0.0.1:0").unwrap();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn bind<A: ToSocketAddrs>(addr: A) -> io::Result<TcpListener> {
super::each_addr(addr, net_imp::TcpListener::bind).map(TcpListener)
}
/// Returns the local socket address of this listener.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{Ipv4Addr, SocketAddr, SocketAddrV4, TcpListener};
///
/// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
/// assert_eq!(listener.local_addr().unwrap(),
/// SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn local_addr(&self) -> io::Result<SocketAddr> {
self.0.socket_addr()
}
/// Creates a new independently owned handle to the underlying socket.
///
/// The returned [`TcpListener`] is a reference to the same socket that this
/// object references. Both handles can be used to accept incoming
/// connections and options set on one listener will affect the other.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
/// let listener_clone = listener.try_clone().unwrap();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn try_clone(&self) -> io::Result<TcpListener> {
self.0.duplicate().map(TcpListener)
}
/// Accept a new incoming connection from this listener.
///
/// This function will block the calling thread until a new TCP connection
/// is established. When established, the corresponding [`TcpStream`] and the
/// remote peer's address will be returned.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
/// match listener.accept() {
/// Ok((_socket, addr)) => println!("new client: {addr:?}"),
/// Err(e) => println!("couldn't get client: {e:?}"),
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
// On WASM, `TcpStream` is uninhabited (as it's unsupported) and so
// the `a` variable here is technically unused.
#[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
self.0.accept().map(|(a, b)| (TcpStream(a), b))
}
/// Returns an iterator over the connections being received on this
/// listener.
///
/// The returned iterator will never return [`None`] and will also not yield
/// the peer's [`SocketAddr`] structure. Iterating over it is equivalent to
/// calling [`TcpListener::accept`] in a loop.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:{TcpListener, TcpStream};
///
/// fn handle_connection(stream: TcpStream) {
/// //...
/// }
///
/// fn main() -> std::io::Result<()> {
/// let listener = TcpListener::bind("127.0.0.1:80")?;
///
/// for stream in listener.incoming() {
/// match stream {
/// Ok(stream) => {
/// handle_connection(stream);
/// }
/// Err(e) => { /* connection failed */ }
/// }
/// }
/// Ok(())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn incoming(&self) -> Incoming<'_> {
Incoming { listener: self }
}
/// Turn this into an iterator over the connections being received on this
/// listener.
///
/// The returned iterator will never return [`None`] and will also not yield
/// the peer's [`SocketAddr`] structure. Iterating over it is equivalent to
/// calling [`TcpListener::accept`] in a loop.
///
/// # Examples
///
/// ```no_run
/// #![feature(tcplistener_into_incoming)]
/// use std:🥅:{TcpListener, TcpStream};
///
/// fn listen_on(port: u16) -> impl Iterator<Item = TcpStream> {
/// let listener = TcpListener::bind(("127.0.0.1", port)).unwrap();
/// listener.into_incoming()
/// .filter_map(Result::ok) /* Ignore failed connections */
/// }
///
/// fn main() -> std::io::Result<()> {
/// for stream in listen_on(80) {
/// /* handle the connection here */
/// }
/// Ok(())
/// }
/// ```
#[must_use = "`self` will be dropped if the result is not used"]
#[unstable(feature = "tcplistener_into_incoming", issue = "88373")]
pub fn into_incoming(self) -> IntoIncoming {
IntoIncoming { listener: self }
}
/// Sets the value for the `IP_TTL` option on this socket.
///
/// This value sets the time-to-live field that is used in every packet sent
/// from this socket.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
/// listener.set_ttl(100).expect("could not set TTL");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
self.0.set_ttl(ttl)
}
/// Gets the value of the `IP_TTL` option for this socket.
///
/// For more information about this option, see [`TcpListener::set_ttl`].
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
/// listener.set_ttl(100).expect("could not set TTL");
/// assert_eq!(listener.ttl().unwrap_or(0), 100);
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn ttl(&self) -> io::Result<u32> {
self.0.ttl()
}
#[stable(feature = "net2_mutators", since = "1.9.0")]
#[deprecated(since = "1.16.0", note = "this option can only be set before the socket is bound")]
#[allow(missing_docs)]
pub fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
self.0.set_only_v6(only_v6)
}
#[stable(feature = "net2_mutators", since = "1.9.0")]
#[deprecated(since = "1.16.0", note = "this option can only be set before the socket is bound")]
#[allow(missing_docs)]
pub fn only_v6(&self) -> io::Result<bool> {
self.0.only_v6()
}
/// Gets the value of the `SO_ERROR` option on this socket.
///
/// This will retrieve the stored error in the underlying socket, clearing
/// the field in the process. This can be useful for checking errors between
/// calls.
///
/// # Examples
///
/// ```no_run
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
/// listener.take_error().expect("No error was expected");
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn take_error(&self) -> io::Result<Option<io::Error>> {
self.0.take_error()
}
/// Moves this TCP stream into or out of nonblocking mode.
///
/// This will result in the `accept` operation becoming nonblocking,
/// i.e., immediately returning from their calls. If the IO operation is
/// successful, `Ok` is returned and no further action is required. If the
/// IO operation could not be completed and needs to be retried, an error
/// with kind [`io::ErrorKind::WouldBlock`] is returned.
///
/// On Unix platforms, calling this method corresponds to calling `fcntl`
/// `FIONBIO`. On Windows calling this method corresponds to calling
/// `ioctlsocket` `FIONBIO`.
///
/// # Examples
///
/// Bind a TCP listener to an address, listen for connections, and read
/// bytes in nonblocking mode:
///
/// ```no_run
/// use std::io;
/// use std:🥅:TcpListener;
///
/// let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
/// listener.set_nonblocking(true).expect("Cannot set non-blocking");
///
/// # fn wait_for_fd() { unimplemented!() }
/// # fn handle_connection(stream: std:🥅:TcpStream) { unimplemented!() }
/// for stream in listener.incoming() {
/// match stream {
/// Ok(s) => {
/// // do something with the TcpStream
/// handle_connection(s);
/// }
/// Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
/// // wait until network socket is ready, typically implemented
/// // via platform-specific APIs such as epoll or IOCP
/// wait_for_fd();
/// continue;
/// }
/// Err(e) => panic!("encountered IO error: {e}"),
/// }
/// }
/// ```
#[stable(feature = "net2_mutators", since = "1.9.0")]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
self.0.set_nonblocking(nonblocking)
}
}
// In addition to the `impl`s here, `TcpListener` also has `impl`s for
// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
// `AsSocket`/`From<OwnedSocket>`/`Into<OwnedSocket>` and
// `AsRawSocket`/`IntoRawSocket`/`FromRawSocket` on Windows.
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Incoming<'a> {
type Item = io::Result<TcpStream>;
fn next(&mut self) -> Option<io::Result<TcpStream>> {
Some(self.listener.accept().map(|p| p.0))
}
}
#[stable(feature = "tcp_listener_incoming_fused_iterator", since = "1.64.0")]
impl FusedIterator for Incoming<'_> {}
#[unstable(feature = "tcplistener_into_incoming", issue = "88373")]
impl Iterator for IntoIncoming {
type Item = io::Result<TcpStream>;
fn next(&mut self) -> Option<io::Result<TcpStream>> {
Some(self.listener.accept().map(|p| p.0))
}
}
#[unstable(feature = "tcplistener_into_incoming", issue = "88373")]
impl FusedIterator for IntoIncoming {}
impl AsInner<net_imp::TcpListener> for TcpListener {
#[inline]
fn as_inner(&self) -> &net_imp::TcpListener {
&self.0
}
}
impl FromInner<net_imp::TcpListener> for TcpListener {
fn from_inner(inner: net_imp::TcpListener) -> TcpListener {
TcpListener(inner)
}
}
impl IntoInner<net_imp::TcpListener> for TcpListener {
fn into_inner(self) -> net_imp::TcpListener {
self.0
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for TcpListener {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}