library/std/src/net/tcp.rs

   1 #![deny(unsafe_op_in_unsafe_fn)]
   2
   3 #[cfg(all(test, not(target_os = "emscripten")))]
   4 mod tests;
   5
   6 use crate::io::prelude::*;
   7
   8 use crate::fmt;
   9 use crate::io::{self, IoSlice, IoSliceMut};
  10 use crate::iter::FusedIterator;
  11 use crate::net::{Shutdown, SocketAddr, ToSocketAddrs};
  12 use crate::sys_common::net as net_imp;
  13 use crate::sys_common::{AsInner, FromInner, IntoInner};
  14 use crate::time::Duration;
  15
  16 /// A TCP stream between a local and a remote socket.
  17 ///
  18 /// After creating a `TcpStream` by either [`connect`]ing to a remote host or
  19 /// [`accept`]ing a connection on a [`TcpListener`], data can be transmitted
  20 /// by [reading] and [writing] to it.
  21 ///
  22 /// The connection will be closed when the value is dropped. The reading and writing
  23 /// portions of the connection can also be shut down individually with the [`shutdown`]
  24 /// method.
  25 ///
  26 /// The Transmission Control Protocol is specified in [IETF RFC 793].
  27 ///
  28 /// [`accept`]: TcpListener::accept
  29 /// [`connect`]: TcpStream::connect
  30 /// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
  31 /// [reading]: Read
  32 /// [`shutdown`]: TcpStream::shutdown
  33 /// [writing]: Write
  34 ///
  35 /// # Examples
  36 ///
  37 /// ```no_run
  38 /// use std::io::prelude::*;
  39 /// use std::net::TcpStream;
  40 ///
  41 /// fn main() -> std::io::Result<()> {
  42 ///     let mut stream = TcpStream::connect("127.0.0.1:34254")?;
  43 ///
  44 ///     stream.write(&[1])?;
  45 ///     stream.read(&mut [0; 128])?;
  46 ///     Ok(())
  47 /// } // the stream is closed here
  48 /// ```
  49 #[stable(feature = "rust1", since = "1.0.0")]
  50 pub struct TcpStream(net_imp::TcpStream);
  51
  52 /// A TCP socket server, listening for connections.
  53 ///
  54 /// After creating a `TcpListener` by [`bind`]ing it to a socket address, it listens
  55 /// for incoming TCP connections. These can be accepted by calling [`accept`] or by
  56 /// iterating over the [`Incoming`] iterator returned by [`incoming`][`TcpListener::incoming`].
  57 ///
  58 /// The socket will be closed when the value is dropped.
  59 ///
  60 /// The Transmission Control Protocol is specified in [IETF RFC 793].
  61 ///
  62 /// [`accept`]: TcpListener::accept
  63 /// [`bind`]: TcpListener::bind
  64 /// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
  65 ///
  66 /// # Examples
  67 ///
  68 /// ```no_run
  69 /// use std::net::{TcpListener, TcpStream};
  70 ///
  71 /// fn handle_client(stream: TcpStream) {
  72 ///     // ...
  73 /// }
  74 ///
  75 /// fn main() -> std::io::Result<()> {
  76 ///     let listener = TcpListener::bind("127.0.0.1:80")?;
  77 ///
  78 ///     // accept connections and process them serially
  79 ///     for stream in listener.incoming() {
  80 ///         handle_client(stream?);
  81 ///     }
  82 ///     Ok(())
  83 /// }
  84 /// ```
  85 #[stable(feature = "rust1", since = "1.0.0")]
  86 pub struct TcpListener(net_imp::TcpListener);
  87
  88 /// An iterator that infinitely [`accept`]s connections on a [`TcpListener`].
  89 ///
  90 /// This `struct` is created by the [`TcpListener::incoming`] method.
  91 /// See its documentation for more.
  92 ///
  93 /// [`accept`]: TcpListener::accept
  94 #[must_use = "iterators are lazy and do nothing unless consumed"]
  95 #[stable(feature = "rust1", since = "1.0.0")]
  96 #[derive(Debug)]
  97 pub struct Incoming<'a> {
  98     listener: &'a TcpListener,
  99 }
 100
 101 /// An iterator that infinitely [`accept`]s connections on a [`TcpListener`].
 102 ///
 103 /// This `struct` is created by the [`TcpListener::into_incoming`] method.
 104 /// See its documentation for more.
 105 ///
 106 /// [`accept`]: TcpListener::accept
 107 #[derive(Debug)]
 108 #[unstable(feature = "tcplistener_into_incoming", issue = "88339")]
 109 pub struct IntoIncoming {
 110     listener: TcpListener,
 111 }
 112
 113 impl TcpStream {
 114     /// Opens a TCP connection to a remote host.
 115     ///
 116     /// `addr` is an address of the remote host. Anything which implements
 117     /// [`ToSocketAddrs`] trait can be supplied for the address; see this trait
 118     /// documentation for concrete examples.
 119     ///
 120     /// If `addr` yields multiple addresses, `connect` will be attempted with
 121     /// each of the addresses until a connection is successful. If none of
 122     /// the addresses result in a successful connection, the error returned from
 123     /// the last connection attempt (the last address) is returned.
 124     ///
 125     /// # Examples
 126     ///
 127     /// Open a TCP connection to `127.0.0.1:8080`:
 128     ///
 129     /// ```no_run
 130     /// use std::net::TcpStream;
 131     ///
 132     /// if let Ok(stream) = TcpStream::connect("127.0.0.1:8080") {
 133     ///     println!("Connected to the server!");
 134     /// } else {
 135     ///     println!("Couldn't connect to server...");
 136     /// }
 137     /// ```
 138     ///
 139     /// Open a TCP connection to `127.0.0.1:8080`. If the connection fails, open
 140     /// a TCP connection to `127.0.0.1:8081`:
 141     ///
 142     /// ```no_run
 143     /// use std::net::{SocketAddr, TcpStream};
 144     ///
 145     /// let addrs = [
 146     ///     SocketAddr::from(([127, 0, 0, 1], 8080)),
 147     ///     SocketAddr::from(([127, 0, 0, 1], 8081)),
 148     /// ];
 149     /// if let Ok(stream) = TcpStream::connect(&addrs[..]) {
 150     ///     println!("Connected to the server!");
 151     /// } else {
 152     ///     println!("Couldn't connect to server...");
 153     /// }
 154     /// ```
 155     #[stable(feature = "rust1", since = "1.0.0")]
 156     pub fn connect<A: ToSocketAddrs>(addr: A) -> io::Result<TcpStream> {
 157         super::each_addr(addr, net_imp::TcpStream::connect).map(TcpStream)
 158     }
 159
 160     /// Opens a TCP connection to a remote host with a timeout.
 161     ///
 162     /// Unlike `connect`, `connect_timeout` takes a single [`SocketAddr`] since
 163     /// timeout must be applied to individual addresses.
 164     ///
 165     /// It is an error to pass a zero `Duration` to this function.
 166     ///
 167     /// Unlike other methods on `TcpStream`, this does not correspond to a
 168     /// single system call. It instead calls `connect` in nonblocking mode and
 169     /// then uses an OS-specific mechanism to await the completion of the
 170     /// connection request.
 171     #[stable(feature = "tcpstream_connect_timeout", since = "1.21.0")]
 172     pub fn connect_timeout(addr: &SocketAddr, timeout: Duration) -> io::Result<TcpStream> {
 173         net_imp::TcpStream::connect_timeout(addr, timeout).map(TcpStream)
 174     }
 175
 176     /// Returns the socket address of the remote peer of this TCP connection.
 177     ///
 178     /// # Examples
 179     ///
 180     /// ```no_run
 181     /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpStream};
 182     ///
 183     /// let stream = TcpStream::connect("127.0.0.1:8080")
 184     ///                        .expect("Couldn't connect to the server...");
 185     /// assert_eq!(stream.peer_addr().unwrap(),
 186     ///            SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
 187     /// ```
 188     #[stable(feature = "rust1", since = "1.0.0")]
 189     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
 190         self.0.peer_addr()
 191     }
 192
 193     /// Returns the socket address of the local half of this TCP connection.
 194     ///
 195     /// # Examples
 196     ///
 197     /// ```no_run
 198     /// use std::net::{IpAddr, Ipv4Addr, TcpStream};
 199     ///
 200     /// let stream = TcpStream::connect("127.0.0.1:8080")
 201     ///                        .expect("Couldn't connect to the server...");
 202     /// assert_eq!(stream.local_addr().unwrap().ip(),
 203     ///            IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
 204     /// ```
 205     #[stable(feature = "rust1", since = "1.0.0")]
 206     pub fn local_addr(&self) -> io::Result<SocketAddr> {
 207         self.0.socket_addr()
 208     }
 209
 210     /// Shuts down the read, write, or both halves of this connection.
 211     ///
 212     /// This function will cause all pending and future I/O on the specified
 213     /// portions to return immediately with an appropriate value (see the
 214     /// documentation of [`Shutdown`]).
 215     ///
 216     /// # Platform-specific behavior
 217     ///
 218     /// Calling this function multiple times may result in different behavior,
 219     /// depending on the operating system. On Linux, the second call will
 220     /// return `Ok(())`, but on macOS, it will return `ErrorKind::NotConnected`.
 221     /// This may change in the future.
 222     ///
 223     /// # Examples
 224     ///
 225     /// ```no_run
 226     /// use std::net::{Shutdown, TcpStream};
 227     ///
 228     /// let stream = TcpStream::connect("127.0.0.1:8080")
 229     ///                        .expect("Couldn't connect to the server...");
 230     /// stream.shutdown(Shutdown::Both).expect("shutdown call failed");
 231     /// ```
 232     #[stable(feature = "rust1", since = "1.0.0")]
 233     pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
 234         self.0.shutdown(how)
 235     }
 236
 237     /// Creates a new independently owned handle to the underlying socket.
 238     ///
 239     /// The returned `TcpStream` is a reference to the same stream that this
 240     /// object references. Both handles will read and write the same stream of
 241     /// data, and options set on one stream will be propagated to the other
 242     /// stream.
 243     ///
 244     /// # Examples
 245     ///
 246     /// ```no_run
 247     /// use std::net::TcpStream;
 248     ///
 249     /// let stream = TcpStream::connect("127.0.0.1:8080")
 250     ///                        .expect("Couldn't connect to the server...");
 251     /// let stream_clone = stream.try_clone().expect("clone failed...");
 252     /// ```
 253     #[stable(feature = "rust1", since = "1.0.0")]
 254     pub fn try_clone(&self) -> io::Result<TcpStream> {
 255         self.0.duplicate().map(TcpStream)
 256     }
 257
 258     /// Sets the read timeout to the timeout specified.
 259     ///
 260     /// If the value specified is [`None`], then [`read`] calls will block
 261     /// indefinitely. An [`Err`] is returned if the zero [`Duration`] is
 262     /// passed to this method.
 263     ///
 264     /// # Platform-specific behavior
 265     ///
 266     /// Platforms may return a different error code whenever a read times out as
 267     /// a result of setting this option. For example Unix typically returns an
 268     /// error of the kind [`WouldBlock`], but Windows may return [`TimedOut`].
 269     ///
 270     /// [`read`]: Read::read
 271     /// [`WouldBlock`]: io::ErrorKind::WouldBlock
 272     /// [`TimedOut`]: io::ErrorKind::TimedOut
 273     ///
 274     /// # Examples
 275     ///
 276     /// ```no_run
 277     /// use std::net::TcpStream;
 278     ///
 279     /// let stream = TcpStream::connect("127.0.0.1:8080")
 280     ///                        .expect("Couldn't connect to the server...");
 281     /// stream.set_read_timeout(None).expect("set_read_timeout call failed");
 282     /// ```
 283     ///
 284     /// An [`Err`] is returned if the zero [`Duration`] is passed to this
 285     /// method:
 286     ///
 287     /// ```no_run
 288     /// use std::io;
 289     /// use std::net::TcpStream;
 290     /// use std::time::Duration;
 291     ///
 292     /// let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
 293     /// let result = stream.set_read_timeout(Some(Duration::new(0, 0)));
 294     /// let err = result.unwrap_err();
 295     /// assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
 296     /// ```
 297     #[stable(feature = "socket_timeout", since = "1.4.0")]
 298     pub fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
 299         self.0.set_read_timeout(dur)
 300     }
 301
 302     /// Sets the write timeout to the timeout specified.
 303     ///
 304     /// If the value specified is [`None`], then [`write`] calls will block
 305     /// indefinitely. An [`Err`] is returned if the zero [`Duration`] is
 306     /// passed to this method.
 307     ///
 308     /// # Platform-specific behavior
 309     ///
 310     /// Platforms may return a different error code whenever a write times out
 311     /// as a result of setting this option. For example Unix typically returns
 312     /// an error of the kind [`WouldBlock`], but Windows may return [`TimedOut`].
 313     ///
 314     /// [`write`]: Write::write
 315     /// [`WouldBlock`]: io::ErrorKind::WouldBlock
 316     /// [`TimedOut`]: io::ErrorKind::TimedOut
 317     ///
 318     /// # Examples
 319     ///
 320     /// ```no_run
 321     /// use std::net::TcpStream;
 322     ///
 323     /// let stream = TcpStream::connect("127.0.0.1:8080")
 324     ///                        .expect("Couldn't connect to the server...");
 325     /// stream.set_write_timeout(None).expect("set_write_timeout call failed");
 326     /// ```
 327     ///
 328     /// An [`Err`] is returned if the zero [`Duration`] is passed to this
 329     /// method:
 330     ///
 331     /// ```no_run
 332     /// use std::io;
 333     /// use std::net::TcpStream;
 334     /// use std::time::Duration;
 335     ///
 336     /// let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
 337     /// let result = stream.set_write_timeout(Some(Duration::new(0, 0)));
 338     /// let err = result.unwrap_err();
 339     /// assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
 340     /// ```
 341     #[stable(feature = "socket_timeout", since = "1.4.0")]
 342     pub fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
 343         self.0.set_write_timeout(dur)
 344     }
 345
 346     /// Returns the read timeout of this socket.
 347     ///
 348     /// If the timeout is [`None`], then [`read`] calls will block indefinitely.
 349     ///
 350     /// # Platform-specific behavior
 351     ///
 352     /// Some platforms do not provide access to the current timeout.
 353     ///
 354     /// [`read`]: Read::read
 355     ///
 356     /// # Examples
 357     ///
 358     /// ```no_run
 359     /// use std::net::TcpStream;
 360     ///
 361     /// let stream = TcpStream::connect("127.0.0.1:8080")
 362     ///                        .expect("Couldn't connect to the server...");
 363     /// stream.set_read_timeout(None).expect("set_read_timeout call failed");
 364     /// assert_eq!(stream.read_timeout().unwrap(), None);
 365     /// ```
 366     #[stable(feature = "socket_timeout", since = "1.4.0")]
 367     pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
 368         self.0.read_timeout()
 369     }
 370
 371     /// Returns the write timeout of this socket.
 372     ///
 373     /// If the timeout is [`None`], then [`write`] calls will block indefinitely.
 374     ///
 375     /// # Platform-specific behavior
 376     ///
 377     /// Some platforms do not provide access to the current timeout.
 378     ///
 379     /// [`write`]: Write::write
 380     ///
 381     /// # Examples
 382     ///
 383     /// ```no_run
 384     /// use std::net::TcpStream;
 385     ///
 386     /// let stream = TcpStream::connect("127.0.0.1:8080")
 387     ///                        .expect("Couldn't connect to the server...");
 388     /// stream.set_write_timeout(None).expect("set_write_timeout call failed");
 389     /// assert_eq!(stream.write_timeout().unwrap(), None);
 390     /// ```
 391     #[stable(feature = "socket_timeout", since = "1.4.0")]
 392     pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
 393         self.0.write_timeout()
 394     }
 395
 396     /// Receives data on the socket from the remote address to which it is
 397     /// connected, without removing that data from the queue. On success,
 398     /// returns the number of bytes peeked.
 399     ///
 400     /// Successive calls return the same data. This is accomplished by passing
 401     /// `MSG_PEEK` as a flag to the underlying `recv` system call.
 402     ///
 403     /// # Examples
 404     ///
 405     /// ```no_run
 406     /// use std::net::TcpStream;
 407     ///
 408     /// let stream = TcpStream::connect("127.0.0.1:8000")
 409     ///                        .expect("Couldn't connect to the server...");
 410     /// let mut buf = [0; 10];
 411     /// let len = stream.peek(&mut buf).expect("peek failed");
 412     /// ```
 413     #[stable(feature = "peek", since = "1.18.0")]
 414     pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
 415         self.0.peek(buf)
 416     }
 417
 418     /// Sets the value of the `SO_LINGER` option on this socket.
 419     ///
 420     /// This value controls how the socket is closed when data remains
 421     /// to be sent. If `SO_LINGER` is set, the socket will remain open
 422     /// for the specified duration as the system attempts to send pending data.
 423     /// Otherwise, the system may close the socket immediately, or wait for a
 424     /// default timeout.
 425     ///
 426     /// # Examples
 427     ///
 428     /// ```no_run
 429     /// #![feature(tcp_linger)]
 430     ///
 431     /// use std::net::TcpStream;
 432     /// use std::time::Duration;
 433     ///
 434     /// let stream = TcpStream::connect("127.0.0.1:8080")
 435     ///                        .expect("Couldn't connect to the server...");
 436     /// stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
 437     /// ```
 438     #[unstable(feature = "tcp_linger", issue = "88494")]
 439     pub fn set_linger(&self, linger: Option<Duration>) -> io::Result<()> {
 440         self.0.set_linger(linger)
 441     }
 442
 443     /// Gets the value of the `SO_LINGER` option on this socket.
 444     ///
 445     /// For more information about this option, see [`TcpStream::set_linger`].
 446     ///
 447     /// # Examples
 448     ///
 449     /// ```no_run
 450     /// #![feature(tcp_linger)]
 451     ///
 452     /// use std::net::TcpStream;
 453     /// use std::time::Duration;
 454     ///
 455     /// let stream = TcpStream::connect("127.0.0.1:8080")
 456     ///                        .expect("Couldn't connect to the server...");
 457     /// stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
 458     /// assert_eq!(stream.linger().unwrap(), Some(Duration::from_secs(0)));
 459     /// ```
 460     #[unstable(feature = "tcp_linger", issue = "88494")]
 461     pub fn linger(&self) -> io::Result<Option<Duration>> {
 462         self.0.linger()
 463     }
 464
 465     /// Sets the value of the `TCP_NODELAY` option on this socket.
 466     ///
 467     /// If set, this option disables the Nagle algorithm. This means that
 468     /// segments are always sent as soon as possible, even if there is only a
 469     /// small amount of data. When not set, data is buffered until there is a
 470     /// sufficient amount to send out, thereby avoiding the frequent sending of
 471     /// small packets.
 472     ///
 473     /// # Examples
 474     ///
 475     /// ```no_run
 476     /// use std::net::TcpStream;
 477     ///
 478     /// let stream = TcpStream::connect("127.0.0.1:8080")
 479     ///                        .expect("Couldn't connect to the server...");
 480     /// stream.set_nodelay(true).expect("set_nodelay call failed");
 481     /// ```
 482     #[stable(feature = "net2_mutators", since = "1.9.0")]
 483     pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
 484         self.0.set_nodelay(nodelay)
 485     }
 486
 487     /// Gets the value of the `TCP_NODELAY` option on this socket.
 488     ///
 489     /// For more information about this option, see [`TcpStream::set_nodelay`].
 490     ///
 491     /// # Examples
 492     ///
 493     /// ```no_run
 494     /// use std::net::TcpStream;
 495     ///
 496     /// let stream = TcpStream::connect("127.0.0.1:8080")
 497     ///                        .expect("Couldn't connect to the server...");
 498     /// stream.set_nodelay(true).expect("set_nodelay call failed");
 499     /// assert_eq!(stream.nodelay().unwrap_or(false), true);
 500     /// ```
 501     #[stable(feature = "net2_mutators", since = "1.9.0")]
 502     pub fn nodelay(&self) -> io::Result<bool> {
 503         self.0.nodelay()
 504     }
 505
 506     /// Sets the value for the `IP_TTL` option on this socket.
 507     ///
 508     /// This value sets the time-to-live field that is used in every packet sent
 509     /// from this socket.
 510     ///
 511     /// # Examples
 512     ///
 513     /// ```no_run
 514     /// use std::net::TcpStream;
 515     ///
 516     /// let stream = TcpStream::connect("127.0.0.1:8080")
 517     ///                        .expect("Couldn't connect to the server...");
 518     /// stream.set_ttl(100).expect("set_ttl call failed");
 519     /// ```
 520     #[stable(feature = "net2_mutators", since = "1.9.0")]
 521     pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
 522         self.0.set_ttl(ttl)
 523     }
 524
 525     /// Gets the value of the `IP_TTL` option for this socket.
 526     ///
 527     /// For more information about this option, see [`TcpStream::set_ttl`].
 528     ///
 529     /// # Examples
 530     ///
 531     /// ```no_run
 532     /// use std::net::TcpStream;
 533     ///
 534     /// let stream = TcpStream::connect("127.0.0.1:8080")
 535     ///                        .expect("Couldn't connect to the server...");
 536     /// stream.set_ttl(100).expect("set_ttl call failed");
 537     /// assert_eq!(stream.ttl().unwrap_or(0), 100);
 538     /// ```
 539     #[stable(feature = "net2_mutators", since = "1.9.0")]
 540     pub fn ttl(&self) -> io::Result<u32> {
 541         self.0.ttl()
 542     }
 543
 544     /// Gets the value of the `SO_ERROR` option on this socket.
 545     ///
 546     /// This will retrieve the stored error in the underlying socket, clearing
 547     /// the field in the process. This can be useful for checking errors between
 548     /// calls.
 549     ///
 550     /// # Examples
 551     ///
 552     /// ```no_run
 553     /// use std::net::TcpStream;
 554     ///
 555     /// let stream = TcpStream::connect("127.0.0.1:8080")
 556     ///                        .expect("Couldn't connect to the server...");
 557     /// stream.take_error().expect("No error was expected...");
 558     /// ```
 559     #[stable(feature = "net2_mutators", since = "1.9.0")]
 560     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
 561         self.0.take_error()
 562     }
 563
 564     /// Moves this TCP stream into or out of nonblocking mode.
 565     ///
 566     /// This will result in `read`, `write`, `recv` and `send` operations
 567     /// becoming nonblocking, i.e., immediately returning from their calls.
 568     /// If the IO operation is successful, `Ok` is returned and no further
 569     /// action is required. If the IO operation could not be completed and needs
 570     /// to be retried, an error with kind [`io::ErrorKind::WouldBlock`] is
 571     /// returned.
 572     ///
 573     /// On Unix platforms, calling this method corresponds to calling `fcntl`
 574     /// `FIONBIO`. On Windows calling this method corresponds to calling
 575     /// `ioctlsocket` `FIONBIO`.
 576     ///
 577     /// # Examples
 578     ///
 579     /// Reading bytes from a TCP stream in non-blocking mode:
 580     ///
 581     /// ```no_run
 582     /// use std::io::{self, Read};
 583     /// use std::net::TcpStream;
 584     ///
 585     /// let mut stream = TcpStream::connect("127.0.0.1:7878")
 586     ///     .expect("Couldn't connect to the server...");
 587     /// stream.set_nonblocking(true).expect("set_nonblocking call failed");
 588     ///
 589     /// # fn wait_for_fd() { unimplemented!() }
 590     /// let mut buf = vec![];
 591     /// loop {
 592     ///     match stream.read_to_end(&mut buf) {
 593     ///         Ok(_) => break,
 594     ///         Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
 595     ///             // wait until network socket is ready, typically implemented
 596     ///             // via platform-specific APIs such as epoll or IOCP
 597     ///             wait_for_fd();
 598     ///         }
 599     ///         Err(e) => panic!("encountered IO error: {e}"),
 600     ///     };
 601     /// };
 602     /// println!("bytes: {buf:?}");
 603     /// ```
 604     #[stable(feature = "net2_mutators", since = "1.9.0")]
 605     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
 606         self.0.set_nonblocking(nonblocking)
 607     }
 608 }
 609
 610 // In addition to the `impl`s here, `TcpStream` also has `impl`s for
 611 // `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
 612 // `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
 613 // `AsSocket`/`From<OwnedSocket>`/`Into<OwnedSocket>` and
 614 // `AsRawSocket`/`IntoRawSocket`/`FromRawSocket` on Windows.
 615
 616 #[stable(feature = "rust1", since = "1.0.0")]
 617 impl Read for TcpStream {
 618     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 619         self.0.read(buf)
 620     }
 621
 622     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
 623         self.0.read_vectored(bufs)
 624     }
 625
 626     #[inline]
 627     fn is_read_vectored(&self) -> bool {
 628         self.0.is_read_vectored()
 629     }
 630 }
 631 #[stable(feature = "rust1", since = "1.0.0")]
 632 impl Write for TcpStream {
 633     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
 634         self.0.write(buf)
 635     }
 636
 637     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
 638         self.0.write_vectored(bufs)
 639     }
 640
 641     #[inline]
 642     fn is_write_vectored(&self) -> bool {
 643         self.0.is_write_vectored()
 644     }
 645
 646     fn flush(&mut self) -> io::Result<()> {
 647         Ok(())
 648     }
 649 }
 650 #[stable(feature = "rust1", since = "1.0.0")]
 651 impl Read for &TcpStream {
 652     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 653         self.0.read(buf)
 654     }
 655
 656     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
 657         self.0.read_vectored(bufs)
 658     }
 659
 660     #[inline]
 661     fn is_read_vectored(&self) -> bool {
 662         self.0.is_read_vectored()
 663     }
 664 }
 665 #[stable(feature = "rust1", since = "1.0.0")]
 666 impl Write for &TcpStream {
 667     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
 668         self.0.write(buf)
 669     }
 670
 671     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
 672         self.0.write_vectored(bufs)
 673     }
 674
 675     #[inline]
 676     fn is_write_vectored(&self) -> bool {
 677         self.0.is_write_vectored()
 678     }
 679
 680     fn flush(&mut self) -> io::Result<()> {
 681         Ok(())
 682     }
 683 }
 684
 685 impl AsInner<net_imp::TcpStream> for TcpStream {
 686     fn as_inner(&self) -> &net_imp::TcpStream {
 687         &self.0
 688     }
 689 }
 690
 691 impl FromInner<net_imp::TcpStream> for TcpStream {
 692     fn from_inner(inner: net_imp::TcpStream) -> TcpStream {
 693         TcpStream(inner)
 694     }
 695 }
 696
 697 impl IntoInner<net_imp::TcpStream> for TcpStream {
 698     fn into_inner(self) -> net_imp::TcpStream {
 699         self.0
 700     }
 701 }
 702
 703 #[stable(feature = "rust1", since = "1.0.0")]
 704 impl fmt::Debug for TcpStream {
 705     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 706         self.0.fmt(f)
 707     }
 708 }
 709
 710 impl TcpListener {
 711     /// Creates a new `TcpListener` which will be bound to the specified
 712     /// address.
 713     ///
 714     /// The returned listener is ready for accepting connections.
 715     ///
 716     /// Binding with a port number of 0 will request that the OS assigns a port
 717     /// to this listener. The port allocated can be queried via the
 718     /// [`TcpListener::local_addr`] method.
 719     ///
 720     /// The address type can be any implementor of [`ToSocketAddrs`] trait. See
 721     /// its documentation for concrete examples.
 722     ///
 723     /// If `addr` yields multiple addresses, `bind` will be attempted with
 724     /// each of the addresses until one succeeds and returns the listener. If
 725     /// none of the addresses succeed in creating a listener, the error returned
 726     /// from the last attempt (the last address) is returned.
 727     ///
 728     /// # Examples
 729     ///
 730     /// Creates a TCP listener bound to `127.0.0.1:80`:
 731     ///
 732     /// ```no_run
 733     /// use std::net::TcpListener;
 734     ///
 735     /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
 736     /// ```
 737     ///
 738     /// Creates a TCP listener bound to `127.0.0.1:80`. If that fails, create a
 739     /// TCP listener bound to `127.0.0.1:443`:
 740     ///
 741     /// ```no_run
 742     /// use std::net::{SocketAddr, TcpListener};
 743     ///
 744     /// let addrs = [
 745     ///     SocketAddr::from(([127, 0, 0, 1], 80)),
 746     ///     SocketAddr::from(([127, 0, 0, 1], 443)),
 747     /// ];
 748     /// let listener = TcpListener::bind(&addrs[..]).unwrap();
 749     /// ```
 750     #[stable(feature = "rust1", since = "1.0.0")]
 751     pub fn bind<A: ToSocketAddrs>(addr: A) -> io::Result<TcpListener> {
 752         super::each_addr(addr, net_imp::TcpListener::bind).map(TcpListener)
 753     }
 754
 755     /// Returns the local socket address of this listener.
 756     ///
 757     /// # Examples
 758     ///
 759     /// ```no_run
 760     /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpListener};
 761     ///
 762     /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
 763     /// assert_eq!(listener.local_addr().unwrap(),
 764     ///            SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
 765     /// ```
 766     #[stable(feature = "rust1", since = "1.0.0")]
 767     pub fn local_addr(&self) -> io::Result<SocketAddr> {
 768         self.0.socket_addr()
 769     }
 770
 771     /// Creates a new independently owned handle to the underlying socket.
 772     ///
 773     /// The returned [`TcpListener`] is a reference to the same socket that this
 774     /// object references. Both handles can be used to accept incoming
 775     /// connections and options set on one listener will affect the other.
 776     ///
 777     /// # Examples
 778     ///
 779     /// ```no_run
 780     /// use std::net::TcpListener;
 781     ///
 782     /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
 783     /// let listener_clone = listener.try_clone().unwrap();
 784     /// ```
 785     #[stable(feature = "rust1", since = "1.0.0")]
 786     pub fn try_clone(&self) -> io::Result<TcpListener> {
 787         self.0.duplicate().map(TcpListener)
 788     }
 789
 790     /// Accept a new incoming connection from this listener.
 791     ///
 792     /// This function will block the calling thread until a new TCP connection
 793     /// is established. When established, the corresponding [`TcpStream`] and the
 794     /// remote peer's address will be returned.
 795     ///
 796     /// # Examples
 797     ///
 798     /// ```no_run
 799     /// use std::net::TcpListener;
 800     ///
 801     /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
 802     /// match listener.accept() {
 803     ///     Ok((_socket, addr)) => println!("new client: {addr:?}"),
 804     ///     Err(e) => println!("couldn't get client: {e:?}"),
 805     /// }
 806     /// ```
 807     #[stable(feature = "rust1", since = "1.0.0")]
 808     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
 809         // On WASM, `TcpStream` is uninhabited (as it's unsupported) and so
 810         // the `a` variable here is technically unused.
 811         #[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
 812         self.0.accept().map(|(a, b)| (TcpStream(a), b))
 813     }
 814
 815     /// Returns an iterator over the connections being received on this
 816     /// listener.
 817     ///
 818     /// The returned iterator will never return [`None`] and will also not yield
 819     /// the peer's [`SocketAddr`] structure. Iterating over it is equivalent to
 820     /// calling [`TcpListener::accept`] in a loop.
 821     ///
 822     /// # Examples
 823     ///
 824     /// ```no_run
 825     /// use std::net::{TcpListener, TcpStream};
 826     ///
 827     /// fn handle_connection(stream: TcpStream) {
 828     ///    //...
 829     /// }
 830     ///
 831     /// fn main() -> std::io::Result<()> {
 832     ///     let listener = TcpListener::bind("127.0.0.1:80")?;
 833     ///
 834     ///     for stream in listener.incoming() {
 835     ///         match stream {
 836     ///             Ok(stream) => {
 837     ///                 handle_connection(stream);
 838     ///             }
 839     ///             Err(e) => { /* connection failed */ }
 840     ///         }
 841     ///     }
 842     ///     Ok(())
 843     /// }
 844     /// ```
 845     #[stable(feature = "rust1", since = "1.0.0")]
 846     pub fn incoming(&self) -> Incoming<'_> {
 847         Incoming { listener: self }
 848     }
 849
 850     /// Turn this into an iterator over the connections being received on this
 851     /// listener.
 852     ///
 853     /// The returned iterator will never return [`None`] and will also not yield
 854     /// the peer's [`SocketAddr`] structure. Iterating over it is equivalent to
 855     /// calling [`TcpListener::accept`] in a loop.
 856     ///
 857     /// # Examples
 858     ///
 859     /// ```no_run
 860     /// #![feature(tcplistener_into_incoming)]
 861     /// use std::net::{TcpListener, TcpStream};
 862     ///
 863     /// fn listen_on(port: u16) -> impl Iterator<Item = TcpStream> {
 864     ///     let listener = TcpListener::bind("127.0.0.1:80").unwrap();
 865     ///     listener.into_incoming()
 866     ///         .filter_map(Result::ok) /* Ignore failed connections */
 867     /// }
 868     ///
 869     /// fn main() -> std::io::Result<()> {
 870     ///     for stream in listen_on(80) {
 871     ///         /* handle the connection here */
 872     ///     }
 873     ///     Ok(())
 874     /// }
 875     /// ```
 876     #[must_use = "`self` will be dropped if the result is not used"]
 877     #[unstable(feature = "tcplistener_into_incoming", issue = "88339")]
 878     pub fn into_incoming(self) -> IntoIncoming {
 879         IntoIncoming { listener: self }
 880     }
 881
 882     /// Sets the value for the `IP_TTL` option on this socket.
 883     ///
 884     /// This value sets the time-to-live field that is used in every packet sent
 885     /// from this socket.
 886     ///
 887     /// # Examples
 888     ///
 889     /// ```no_run
 890     /// use std::net::TcpListener;
 891     ///
 892     /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
 893     /// listener.set_ttl(100).expect("could not set TTL");
 894     /// ```
 895     #[stable(feature = "net2_mutators", since = "1.9.0")]
 896     pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
 897         self.0.set_ttl(ttl)
 898     }
 899
 900     /// Gets the value of the `IP_TTL` option for this socket.
 901     ///
 902     /// For more information about this option, see [`TcpListener::set_ttl`].
 903     ///
 904     /// # Examples
 905     ///
 906     /// ```no_run
 907     /// use std::net::TcpListener;
 908     ///
 909     /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
 910     /// listener.set_ttl(100).expect("could not set TTL");
 911     /// assert_eq!(listener.ttl().unwrap_or(0), 100);
 912     /// ```
 913     #[stable(feature = "net2_mutators", since = "1.9.0")]
 914     pub fn ttl(&self) -> io::Result<u32> {
 915         self.0.ttl()
 916     }
 917
 918     #[stable(feature = "net2_mutators", since = "1.9.0")]
 919     #[deprecated(since = "1.16.0", note = "this option can only be set before the socket is bound")]
 920     #[allow(missing_docs)]
 921     pub fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
 922         self.0.set_only_v6(only_v6)
 923     }
 924
 925     #[stable(feature = "net2_mutators", since = "1.9.0")]
 926     #[deprecated(since = "1.16.0", note = "this option can only be set before the socket is bound")]
 927     #[allow(missing_docs)]
 928     pub fn only_v6(&self) -> io::Result<bool> {
 929         self.0.only_v6()
 930     }
 931
 932     /// Gets the value of the `SO_ERROR` option on this socket.
 933     ///
 934     /// This will retrieve the stored error in the underlying socket, clearing
 935     /// the field in the process. This can be useful for checking errors between
 936     /// calls.
 937     ///
 938     /// # Examples
 939     ///
 940     /// ```no_run
 941     /// use std::net::TcpListener;
 942     ///
 943     /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
 944     /// listener.take_error().expect("No error was expected");
 945     /// ```
 946     #[stable(feature = "net2_mutators", since = "1.9.0")]
 947     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
 948         self.0.take_error()
 949     }
 950
 951     /// Moves this TCP stream into or out of nonblocking mode.
 952     ///
 953     /// This will result in the `accept` operation becoming nonblocking,
 954     /// i.e., immediately returning from their calls. If the IO operation is
 955     /// successful, `Ok` is returned and no further action is required. If the
 956     /// IO operation could not be completed and needs to be retried, an error
 957     /// with kind [`io::ErrorKind::WouldBlock`] is returned.
 958     ///
 959     /// On Unix platforms, calling this method corresponds to calling `fcntl`
 960     /// `FIONBIO`. On Windows calling this method corresponds to calling
 961     /// `ioctlsocket` `FIONBIO`.
 962     ///
 963     /// # Examples
 964     ///
 965     /// Bind a TCP listener to an address, listen for connections, and read
 966     /// bytes in nonblocking mode:
 967     ///
 968     /// ```no_run
 969     /// use std::io;
 970     /// use std::net::TcpListener;
 971     ///
 972     /// let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
 973     /// listener.set_nonblocking(true).expect("Cannot set non-blocking");
 974     ///
 975     /// # fn wait_for_fd() { unimplemented!() }
 976     /// # fn handle_connection(stream: std::net::TcpStream) { unimplemented!() }
 977     /// for stream in listener.incoming() {
 978     ///     match stream {
 979     ///         Ok(s) => {
 980     ///             // do something with the TcpStream
 981     ///             handle_connection(s);
 982     ///         }
 983     ///         Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
 984     ///             // wait until network socket is ready, typically implemented
 985     ///             // via platform-specific APIs such as epoll or IOCP
 986     ///             wait_for_fd();
 987     ///             continue;
 988     ///         }
 989     ///         Err(e) => panic!("encountered IO error: {e}"),
 990     ///     }
 991     /// }
 992     /// ```
 993     #[stable(feature = "net2_mutators", since = "1.9.0")]
 994     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
 995         self.0.set_nonblocking(nonblocking)
 996     }
 997 }
 998
 999 // In addition to the `impl`s here, `TcpListener` also has `impl`s for
1000 // `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
1001 // `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
1002 // `AsSocket`/`From<OwnedSocket>`/`Into<OwnedSocket>` and
1003 // `AsRawSocket`/`IntoRawSocket`/`FromRawSocket` on Windows.
1004
1005 #[stable(feature = "rust1", since = "1.0.0")]
1006 impl<'a> Iterator for Incoming<'a> {
1007     type Item = io::Result<TcpStream>;
1008     fn next(&mut self) -> Option<io::Result<TcpStream>> {
1009         Some(self.listener.accept().map(|p| p.0))
1010     }
1011 }
1012
1013 #[stable(feature = "tcp_listener_incoming_fused_iterator", since = "1.64.0")]
1014 impl FusedIterator for Incoming<'_> {}
1015
1016 #[unstable(feature = "tcplistener_into_incoming", issue = "88339")]
1017 impl Iterator for IntoIncoming {
1018     type Item = io::Result<TcpStream>;
1019     fn next(&mut self) -> Option<io::Result<TcpStream>> {
1020         Some(self.listener.accept().map(|p| p.0))
1021     }
1022 }
1023
1024 #[unstable(feature = "tcplistener_into_incoming", issue = "88339")]
1025 impl FusedIterator for IntoIncoming {}
1026
1027 impl AsInner<net_imp::TcpListener> for TcpListener {
1028     fn as_inner(&self) -> &net_imp::TcpListener {
1029         &self.0
1030     }
1031 }
1032
1033 impl FromInner<net_imp::TcpListener> for TcpListener {
1034     fn from_inner(inner: net_imp::TcpListener) -> TcpListener {
1035         TcpListener(inner)
1036     }
1037 }
1038
1039 impl IntoInner<net_imp::TcpListener> for TcpListener {
1040     fn into_inner(self) -> net_imp::TcpListener {
1041         self.0
1042     }
1043 }
1044
1045 #[stable(feature = "rust1", since = "1.0.0")]
1046 impl fmt::Debug for TcpListener {
1047     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1048         self.0.fmt(f)
1049     }
1050 }