From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- library/std/src/net/udp.rs | 813 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 813 insertions(+) create mode 100644 library/std/src/net/udp.rs (limited to 'library/std/src/net/udp.rs') diff --git a/library/std/src/net/udp.rs b/library/std/src/net/udp.rs new file mode 100644 index 000000000..864e1b0f3 --- /dev/null +++ b/library/std/src/net/udp.rs @@ -0,0 +1,813 @@ +#[cfg(all(test, not(any(target_os = "emscripten", target_env = "sgx"))))] +mod tests; + +use crate::fmt; +use crate::io::{self, ErrorKind}; +use crate::net::{Ipv4Addr, Ipv6Addr, SocketAddr, ToSocketAddrs}; +use crate::sys_common::net as net_imp; +use crate::sys_common::{AsInner, FromInner, IntoInner}; +use crate::time::Duration; + +/// A UDP socket. +/// +/// After creating a `UdpSocket` by [`bind`]ing it to a socket address, data can be +/// [sent to] and [received from] any other socket address. +/// +/// 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`], data can be sent to and received from that address with +/// [`send`] and [`recv`]. +/// +/// As stated in the User Datagram Protocol's specification in [IETF RFC 768], UDP is +/// an unordered, unreliable protocol; refer to [`TcpListener`] and [`TcpStream`] for TCP +/// primitives. +/// +/// [`bind`]: UdpSocket::bind +/// [`connect`]: UdpSocket::connect +/// [IETF RFC 768]: https://tools.ietf.org/html/rfc768 +/// [`recv`]: UdpSocket::recv +/// [received from]: UdpSocket::recv_from +/// [`send`]: UdpSocket::send +/// [sent to]: UdpSocket::send_to +/// [`TcpListener`]: crate::net::TcpListener +/// [`TcpStream`]: crate::net::TcpStream +/// +/// # Examples +/// +/// ```no_run +/// use std::net::UdpSocket; +/// +/// fn main() -> std::io::Result<()> { +/// { +/// let socket = UdpSocket::bind("127.0.0.1:34254")?; +/// +/// // Receives a single datagram message on the socket. If `buf` is too small to hold +/// // the message, it will be cut off. +/// let mut buf = [0; 10]; +/// let (amt, src) = socket.recv_from(&mut buf)?; +/// +/// // Redeclare `buf` as slice of the received data and send reverse data back to origin. +/// let buf = &mut buf[..amt]; +/// buf.reverse(); +/// socket.send_to(buf, &src)?; +/// } // the socket is closed here +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub struct UdpSocket(net_imp::UdpSocket); + +impl UdpSocket { + /// Creates a UDP socket from the given address. + /// + /// 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 socket. If none + /// of the addresses succeed in creating a socket, the error returned from + /// the last attempt (the last address) is returned. + /// + /// # Examples + /// + /// Creates a UDP socket bound to `127.0.0.1:3400`: + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:3400").expect("couldn't bind to address"); + /// ``` + /// + /// Creates a UDP socket bound to `127.0.0.1:3400`. If the socket cannot be + /// bound to that address, create a UDP socket bound to `127.0.0.1:3401`: + /// + /// ```no_run + /// use std::net::{SocketAddr, UdpSocket}; + /// + /// let addrs = [ + /// SocketAddr::from(([127, 0, 0, 1], 3400)), + /// SocketAddr::from(([127, 0, 0, 1], 3401)), + /// ]; + /// let socket = UdpSocket::bind(&addrs[..]).expect("couldn't bind to address"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn bind(addr: A) -> io::Result { + super::each_addr(addr, net_imp::UdpSocket::bind).map(UdpSocket) + } + + /// Receives a single datagram message on the socket. On success, returns the number + /// of bytes read and the origin. + /// + /// The function must be called with valid byte array `buf` of sufficient size to + /// hold the message bytes. If a message is too long to fit in the supplied buffer, + /// excess bytes may be discarded. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// let mut buf = [0; 10]; + /// let (number_of_bytes, src_addr) = socket.recv_from(&mut buf) + /// .expect("Didn't receive data"); + /// let filled_buf = &mut buf[..number_of_bytes]; + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> { + self.0.recv_from(buf) + } + + /// Receives a single datagram message on the socket, without removing it from the + /// queue. On success, returns the number of bytes read and the origin. + /// + /// The function must be called with valid byte array `buf` of sufficient size to + /// hold the message bytes. If a message is too long to fit in the supplied buffer, + /// excess bytes may be discarded. + /// + /// Successive calls return the same data. This is accomplished by passing + /// `MSG_PEEK` as a flag to the underlying `recvfrom` system call. + /// + /// Do not use this function to implement busy waiting, instead use `libc::poll` to + /// synchronize IO events on one or more sockets. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// let mut buf = [0; 10]; + /// let (number_of_bytes, src_addr) = socket.peek_from(&mut buf) + /// .expect("Didn't receive data"); + /// let filled_buf = &mut buf[..number_of_bytes]; + /// ``` + #[stable(feature = "peek", since = "1.18.0")] + pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> { + self.0.peek_from(buf) + } + + /// Sends data on the socket to the given address. On success, returns the + /// number of bytes written. + /// + /// Address type can be any implementor of [`ToSocketAddrs`] trait. See its + /// documentation for concrete examples. + /// + /// It is possible for `addr` to yield multiple addresses, but `send_to` + /// will only send data to the first address yielded by `addr`. + /// + /// This will return an error when the IP version of the local socket + /// does not match that returned from [`ToSocketAddrs`]. + /// + /// See [Issue #34202] for more details. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.send_to(&[0; 10], "127.0.0.1:4242").expect("couldn't send data"); + /// ``` + /// + /// [Issue #34202]: https://github.com/rust-lang/rust/issues/34202 + #[stable(feature = "rust1", since = "1.0.0")] + pub fn send_to(&self, buf: &[u8], addr: A) -> io::Result { + match addr.to_socket_addrs()?.next() { + Some(addr) => self.0.send_to(buf, &addr), + None => { + Err(io::const_io_error!(ErrorKind::InvalidInput, "no addresses to send data to")) + } + } + } + + /// Returns the socket address of the remote peer this socket was connected to. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, UdpSocket}; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.connect("192.168.0.1:41203").expect("couldn't connect to address"); + /// assert_eq!(socket.peer_addr().unwrap(), + /// SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(192, 168, 0, 1), 41203))); + /// ``` + /// + /// If the socket isn't connected, it will return a [`NotConnected`] error. + /// + /// [`NotConnected`]: io::ErrorKind::NotConnected + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// assert_eq!(socket.peer_addr().unwrap_err().kind(), + /// std::io::ErrorKind::NotConnected); + /// ``` + #[stable(feature = "udp_peer_addr", since = "1.40.0")] + pub fn peer_addr(&self) -> io::Result { + self.0.peer_addr() + } + + /// Returns the socket address that this socket was created from. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, UdpSocket}; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// assert_eq!(socket.local_addr().unwrap(), + /// SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 34254))); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn local_addr(&self) -> io::Result { + self.0.socket_addr() + } + + /// Creates a new independently owned handle to the underlying socket. + /// + /// The returned `UdpSocket` is a reference to the same socket that this + /// object references. Both handles will read and write the same port, and + /// options set on one socket will be propagated to the other. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// let socket_clone = socket.try_clone().expect("couldn't clone the socket"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn try_clone(&self) -> io::Result { + self.0.duplicate().map(UdpSocket) + } + + /// 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`]: io::Read::read + /// [`WouldBlock`]: io::ErrorKind::WouldBlock + /// [`TimedOut`]: io::ErrorKind::TimedOut + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.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::net::UdpSocket; + /// use std::time::Duration; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").unwrap(); + /// let result = socket.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) -> 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`]: io::Write::write + /// [`WouldBlock`]: io::ErrorKind::WouldBlock + /// [`TimedOut`]: io::ErrorKind::TimedOut + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.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::net::UdpSocket; + /// use std::time::Duration; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").unwrap(); + /// let result = socket.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) -> 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. + /// + /// [`read`]: io::Read::read + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_read_timeout(None).expect("set_read_timeout call failed"); + /// assert_eq!(socket.read_timeout().unwrap(), None); + /// ``` + #[stable(feature = "socket_timeout", since = "1.4.0")] + pub fn read_timeout(&self) -> io::Result> { + self.0.read_timeout() + } + + /// Returns the write timeout of this socket. + /// + /// If the timeout is [`None`], then [`write`] calls will block indefinitely. + /// + /// [`write`]: io::Write::write + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_write_timeout(None).expect("set_write_timeout call failed"); + /// assert_eq!(socket.write_timeout().unwrap(), None); + /// ``` + #[stable(feature = "socket_timeout", since = "1.4.0")] + pub fn write_timeout(&self) -> io::Result> { + self.0.write_timeout() + } + + /// Sets the value of the `SO_BROADCAST` option for this socket. + /// + /// When enabled, this socket is allowed to send packets to a broadcast + /// address. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_broadcast(false).expect("set_broadcast call failed"); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn set_broadcast(&self, broadcast: bool) -> io::Result<()> { + self.0.set_broadcast(broadcast) + } + + /// Gets the value of the `SO_BROADCAST` option for this socket. + /// + /// For more information about this option, see [`UdpSocket::set_broadcast`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_broadcast(false).expect("set_broadcast call failed"); + /// assert_eq!(socket.broadcast().unwrap(), false); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn broadcast(&self) -> io::Result { + self.0.broadcast() + } + + /// Sets the value of the `IP_MULTICAST_LOOP` option for this socket. + /// + /// If enabled, multicast packets will be looped back to the local socket. + /// Note that this might not have any effect on IPv6 sockets. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_loop_v4(false).expect("set_multicast_loop_v4 call failed"); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn set_multicast_loop_v4(&self, multicast_loop_v4: bool) -> io::Result<()> { + self.0.set_multicast_loop_v4(multicast_loop_v4) + } + + /// Gets the value of the `IP_MULTICAST_LOOP` option for this socket. + /// + /// For more information about this option, see [`UdpSocket::set_multicast_loop_v4`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_loop_v4(false).expect("set_multicast_loop_v4 call failed"); + /// assert_eq!(socket.multicast_loop_v4().unwrap(), false); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn multicast_loop_v4(&self) -> io::Result { + self.0.multicast_loop_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 might not have any effect on IPv6 sockets. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_ttl_v4(42).expect("set_multicast_ttl_v4 call failed"); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn set_multicast_ttl_v4(&self, multicast_ttl_v4: u32) -> io::Result<()> { + self.0.set_multicast_ttl_v4(multicast_ttl_v4) + } + + /// Gets the value of the `IP_MULTICAST_TTL` option for this socket. + /// + /// For more information about this option, see [`UdpSocket::set_multicast_ttl_v4`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_ttl_v4(42).expect("set_multicast_ttl_v4 call failed"); + /// assert_eq!(socket.multicast_ttl_v4().unwrap(), 42); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn multicast_ttl_v4(&self) -> io::Result { + self.0.multicast_ttl_v4() + } + + /// 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 might not have any affect on IPv4 sockets. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_loop_v6(false).expect("set_multicast_loop_v6 call failed"); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn set_multicast_loop_v6(&self, multicast_loop_v6: bool) -> io::Result<()> { + self.0.set_multicast_loop_v6(multicast_loop_v6) + } + + /// Gets the value of the `IPV6_MULTICAST_LOOP` option for this socket. + /// + /// For more information about this option, see [`UdpSocket::set_multicast_loop_v6`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_multicast_loop_v6(false).expect("set_multicast_loop_v6 call failed"); + /// assert_eq!(socket.multicast_loop_v6().unwrap(), false); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn multicast_loop_v6(&self) -> io::Result { + self.0.multicast_loop_v6() + } + + /// 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::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_ttl(42).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 [`UdpSocket::set_ttl`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.set_ttl(42).expect("set_ttl call failed"); + /// assert_eq!(socket.ttl().unwrap(), 42); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn ttl(&self) -> io::Result { + self.0.ttl() + } + + /// Executes an operation of the `IP_ADD_MEMBERSHIP` type. + /// + /// This function specifies a new multicast group for this socket to join. + /// The address 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. + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn join_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr) -> io::Result<()> { + self.0.join_multicast_v4(multiaddr, interface) + } + + /// Executes an operation of the `IPV6_ADD_MEMBERSHIP` type. + /// + /// This function specifies a new multicast group for this socket to join. + /// The address must be a valid multicast address, and `interface` is the + /// index of the interface to join/leave (or 0 to indicate any interface). + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> { + self.0.join_multicast_v6(multiaddr, interface) + } + + /// Executes an operation of the `IP_DROP_MEMBERSHIP` type. + /// + /// For more information about this option, see [`UdpSocket::join_multicast_v4`]. + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn leave_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr) -> io::Result<()> { + self.0.leave_multicast_v4(multiaddr, interface) + } + + /// Executes an operation of the `IPV6_DROP_MEMBERSHIP` type. + /// + /// For more information about this option, see [`UdpSocket::join_multicast_v6`]. + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> { + self.0.leave_multicast_v6(multiaddr, interface) + } + + /// 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::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// match socket.take_error() { + /// Ok(Some(error)) => println!("UdpSocket error: {error:?}"), + /// Ok(None) => println!("No error"), + /// Err(error) => println!("UdpSocket.take_error failed: {error:?}"), + /// } + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn take_error(&self) -> io::Result> { + self.0.take_error() + } + + /// Connects this UDP socket to a remote address, allowing the `send` and + /// `recv` syscalls to be used to send data and also applies filters to only + /// receive data from the specified address. + /// + /// If `addr` yields multiple addresses, `connect` will be attempted with + /// each of the addresses until the underlying OS function returns no + /// error. Note that usually, a successful `connect` call does not specify + /// that there is a remote server listening on the port, rather, such an + /// error would only be detected after the first send. If the OS returns an + /// error for each of the specified addresses, the error returned from the + /// last connection attempt (the last address) is returned. + /// + /// # Examples + /// + /// Creates a UDP socket bound to `127.0.0.1:3400` and connect the socket to + /// `127.0.0.1:8080`: + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:3400").expect("couldn't bind to address"); + /// socket.connect("127.0.0.1:8080").expect("connect function failed"); + /// ``` + /// + /// Unlike in the TCP case, passing an array of addresses to the `connect` + /// function of a UDP socket is not a useful thing to do: The OS will be + /// unable to determine whether something is listening on the remote + /// address without the application sending data. + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn connect(&self, addr: A) -> io::Result<()> { + super::each_addr(addr, |addr| self.0.connect(addr)) + } + + /// Sends data on the socket to the remote address to which it is connected. + /// + /// [`UdpSocket::connect`] will connect this socket to a remote address. This + /// method will fail if the socket is not connected. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.connect("127.0.0.1:8080").expect("connect function failed"); + /// socket.send(&[0, 1, 2]).expect("couldn't send message"); + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn send(&self, buf: &[u8]) -> io::Result { + self.0.send(buf) + } + + /// Receives a single datagram message on the socket from the remote address to + /// which it is connected. On success, returns the number of bytes read. + /// + /// The function must be called with valid byte array `buf` of sufficient size to + /// hold the message bytes. If a message is too long to fit in the supplied buffer, + /// excess bytes may be discarded. + /// + /// [`UdpSocket::connect`] will connect this socket to a remote address. This + /// method will fail if the socket is not connected. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.connect("127.0.0.1:8080").expect("connect function failed"); + /// let mut buf = [0; 10]; + /// match socket.recv(&mut buf) { + /// Ok(received) => println!("received {received} bytes {:?}", &buf[..received]), + /// Err(e) => println!("recv function failed: {e:?}"), + /// } + /// ``` + #[stable(feature = "net2_mutators", since = "1.9.0")] + pub fn recv(&self, buf: &mut [u8]) -> io::Result { + self.0.recv(buf) + } + + /// Receives single datagram on the socket from the remote address to which it is + /// connected, without removing the message from input queue. On success, returns + /// the number of bytes peeked. + /// + /// The function must be called with valid byte array `buf` of sufficient size to + /// hold the message bytes. If a message is too long to fit in the supplied buffer, + /// excess bytes may be discarded. + /// + /// Successive calls return the same data. This is accomplished by passing + /// `MSG_PEEK` as a flag to the underlying `recv` system call. + /// + /// Do not use this function to implement busy waiting, instead use `libc::poll` to + /// synchronize IO events on one or more sockets. + /// + /// [`UdpSocket::connect`] will connect this socket to a remote address. This + /// method will fail if the socket is not connected. + /// + /// # Errors + /// + /// This method will fail if the socket is not connected. The `connect` method + /// will connect this socket to a remote address. + /// + /// # Examples + /// + /// ```no_run + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address"); + /// socket.connect("127.0.0.1:8080").expect("connect function failed"); + /// let mut buf = [0; 10]; + /// match socket.peek(&mut buf) { + /// Ok(received) => println!("received {received} bytes"), + /// Err(e) => println!("peek function failed: {e:?}"), + /// } + /// ``` + #[stable(feature = "peek", since = "1.18.0")] + pub fn peek(&self, buf: &mut [u8]) -> io::Result { + self.0.peek(buf) + } + + /// Moves this UDP socket into or out of nonblocking mode. + /// + /// This will result in `recv`, `recv_from`, `send`, and `send_to` + /// 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 + /// + /// Creates a UDP socket bound to `127.0.0.1:7878` and read bytes in + /// nonblocking mode: + /// + /// ```no_run + /// use std::io; + /// use std::net::UdpSocket; + /// + /// let socket = UdpSocket::bind("127.0.0.1:7878").unwrap(); + /// socket.set_nonblocking(true).unwrap(); + /// + /// # fn wait_for_fd() { unimplemented!() } + /// let mut buf = [0; 10]; + /// let (num_bytes_read, _) = loop { + /// match socket.recv_from(&mut buf) { + /// Ok(n) => break n, + /// 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[..num_bytes_read]); + /// ``` + #[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, `UdpSocket` also has `impl`s for +// `AsFd`/`From`/`Into` and +// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and +// `AsSocket`/`From`/`Into` and +// `AsRawSocket`/`IntoRawSocket`/`FromRawSocket` on Windows. + +impl AsInner for UdpSocket { + fn as_inner(&self) -> &net_imp::UdpSocket { + &self.0 + } +} + +impl FromInner for UdpSocket { + fn from_inner(inner: net_imp::UdpSocket) -> UdpSocket { + UdpSocket(inner) + } +} + +impl IntoInner for UdpSocket { + fn into_inner(self) -> net_imp::UdpSocket { + self.0 + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for UdpSocket { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} -- cgit v1.2.3