std::net::UdpSocket - Rust
Description: API documentation for the Rust `UdpSocket` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, UdpSocket

# Struct std::net::UdpSocket 1.0.0 [−] [src]

    pub struct UdpSocket(_);

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.

# Examples

    use std::net::UdpSocket;

    {
        let mut socket = UdpSocket::bind("127.0.0.1:34254")?;

        // read from the socket
        let mut buf = [0; 10];
        let (amt, src) = socket.recv_from(&mut buf)?;

        // send a reply to the socket we received data from
        let buf = &mut buf[..amt];
        buf.reverse();
        socket.send_to(buf, &src)?;
    } // the socket is closed hereRun

## Methods

### `impl UdpSocket`
[src]

#### `fn bind<A: ToSocketAddrs>(addr: A) -> Result<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.

# Examples

    use std::net::UdpSocket;

    let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address");Run

#### `fn recv_from(&self, buf: &mut [u8]) -> Result<(usize, SocketAddr)>`

Receives data from the socket. On success, returns the number of bytes read and the address from whence the data came.

# Examples

    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");Run

#### `fn peek_from(&self, buf: &mut [u8]) -> Result<(usize, SocketAddr)>`
1.18.0

Receives data from the socket, without removing it from the queue.

Successive calls return the same data. This is accomplished by passing `MSG_PEEK` as a flag to the underlying `recvfrom` system call.

On success, returns the number of bytes peeked and the address from whence the data came.

# Examples

    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");Run

#### `fn send_to<A: ToSocketAddrs>(&self, buf: &[u8], addr: A) -> Result<usize>`

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.

This will return an error when the IP version of the local socket does not match that returned from `ToSocketAddrs`.

See https://github.com/rust-lang/rust/issues/34202 for more details.

# Examples

    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");Run

#### `fn local_addr(&self) -> Result<SocketAddr>`

Returns the socket address that this socket was created from.

# Examples

    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)));Run

#### `fn try_clone(&self) -> Result<UdpSocket>`

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

    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");Run

#### `fn set_read_timeout(&self, dur: Option<Duration>) -> Result<()>`
1.4.0

Sets the read timeout to the timeout specified.

If the value specified is `None`, then `read` calls will block indefinitely. It is an error to pass the zero `Duration` to this method.

# Note

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`.

# Examples

    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");Run

#### `fn set_write_timeout(&self, dur: Option<Duration>) -> Result<()>`
1.4.0

Sets the write timeout to the timeout specified.

If the value specified is `None`, then `write` calls will block indefinitely. It is an error to pass the zero `Duration` to this method.

# Note

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`.

# Examples

    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");Run

#### `fn read_timeout(&self) -> Result<Option<Duration>>`
1.4.0

Returns the read timeout of this socket.

If the timeout is `None`, then `read` calls will block indefinitely.

# Examples

    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);Run

#### `fn write_timeout(&self) -> Result<Option<Duration>>`
1.4.0

Returns the write timeout of this socket.

If the timeout is `None`, then `write` calls will block indefinitely.

# Examples

    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);Run

#### `fn set_broadcast(&self, broadcast: bool) -> Result<()>`
1.9.0

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

    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");Run

#### `fn broadcast(&self) -> Result<bool>`
1.9.0

Gets the value of the `SO_BROADCAST` option for this socket.

For more information about this option, see `set_broadcast`.

# Examples

    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);Run

#### `fn set_multicast_loop_v4(&self, multicast_loop_v4: bool) -> Result<()>`
1.9.0

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 may not have any affect on IPv6 sockets.

# Examples

    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");Run

#### `fn multicast_loop_v4(&self) -> Result<bool>`
1.9.0

Gets the value of the `IP_MULTICAST_LOOP` option for this socket.

For more information about this option, see `set_multicast_loop_v4`.

# Examples

    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);Run

#### `fn set_multicast_ttl_v4(&self, multicast_ttl_v4: u32) -> Result<()>`
1.9.0

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 may not have any affect on IPv6 sockets.

# Examples

    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");Run

#### `fn multicast_ttl_v4(&self) -> Result<u32>`
1.9.0

Gets the value of the `IP_MULTICAST_TTL` option for this socket.

For more information about this option, see `set_multicast_ttl_v4`.

# Examples

    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);Run

#### `fn set_multicast_loop_v6(&self, multicast_loop_v6: bool) -> Result<()>`
1.9.0

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 may not have any affect on IPv4 sockets.

# Examples

    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");Run

#### `fn multicast_loop_v6(&self) -> Result<bool>`
1.9.0

Gets the value of the `IPV6_MULTICAST_LOOP` option for this socket.

For more information about this option, see `set_multicast_loop_v6`.

# Examples

    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);Run

#### `fn set_ttl(&self, ttl: u32) -> Result<()>`
1.9.0

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

    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");Run

#### `fn ttl(&self) -> Result<u32>`
1.9.0

Gets the value of the `IP_TTL` option for this socket.

For more information about this option, see `set_ttl`.

# Examples

    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);Run

#### `fn join_multicast_v4(
&self,
multiaddr: &Ipv4Addr,
interface: &Ipv4Addr
) -> Result<()>`
1.9.0

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.

#### `fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> Result<()>`
1.9.0

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).

#### `fn leave_multicast_v4(
&self,
multiaddr: &Ipv4Addr,
interface: &Ipv4Addr
) -> Result<()>`
1.9.0

Executes an operation of the `IP_DROP_MEMBERSHIP` type.

For more information about this option, see `join_multicast_v4`.

#### `fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> Result<()>`
1.9.0

Executes an operation of the `IPV6_DROP_MEMBERSHIP` type.

For more information about this option, see `join_multicast_v6`.

#### `fn take_error(&self) -> Result<Option<Error>>`
1.9.0

Get 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

    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),
    }Run

#### `fn connect<A: ToSocketAddrs>(&self, addr: A) -> Result<()>`
1.9.0

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.

# Examples

    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");Run

#### `fn send(&self, buf: &[u8]) -> Result<usize>`
1.9.0

Sends data on the socket to the remote address to which it is connected.

The `connect` method will connect this socket to a remote address. This method will fail if the socket is not connected.

# Examples

    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");Run

#### `fn recv(&self, buf: &mut [u8]) -> Result<usize>`
1.9.0

Receives data on the socket from the remote address to which it is connected.

The `connect` method will connect this socket to a remote address. This method will fail if the socket is not connected.

# Examples

    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 {} bytes", received),
        Err(e) => println!("recv function failed: {:?}", e),
    }Run

#### `fn peek(&self, buf: &mut [u8]) -> Result<usize>`
1.18.0

Receives data on the socket from the remote adress 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.

# Errors

This method will fail if the socket is not connected. The `connect` method will connect this socket to a remote address.

# Examples

    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 {} bytes", received),
        Err(e) => println!("peek function failed: {:?}", e),
    }Run

#### `fn set_nonblocking(&self, nonblocking: bool) -> Result<()>`
1.9.0

Moves this UDP socket into or out of nonblocking mode.

On Unix this corresponds to calling fcntl, and on Windows this corresponds to calling ioctlsocket.

# Examples

    use std::net::UdpSocket;

    let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address");
    socket.set_nonblocking(true).expect("set_nonblocking call failed");Run

## Trait Implementations

### `impl Debug for UdpSocket`
[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`

Formats the value using the given formatter.

### `impl AsRawFd for UdpSocket`
[src]

#### `fn as_raw_fd(&self) -> RawFd`

Extracts the raw file descriptor. Read more

### `impl FromRawFd for UdpSocket`
1.1.0
[src]

#### `unsafe fn from_raw_fd(fd: RawFd) -> UdpSocket`

Constructs a new instance of `Self` from the given raw file descriptor. Read more

### `impl IntoRawFd for UdpSocket`
1.4.0
[src]

#### `fn into_raw_fd(self) -> RawFd`

Consumes this object, returning the raw underlying file descriptor. Read more

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