Struct tokio::net::UdpSocket

pub struct UdpSocket { /* private fields */ }

An I/O object representing a UDP socket.

Implementations

impl UdpSocket

pub fn bind(addr: &SocketAddr) -> Result<UdpSocket, Error>

This function will create a new UDP socket and attempt to bind it to the addr provided.

pub fn from_std(socket: UdpSocket, handle: &Handle) -> Result<UdpSocket, Error>

Creates a new UdpSocket from the previously bound socket provided.

The socket given will be registered with the event loop that handle is associated with. This function requires that socket has previously been bound to an address to work correctly.

This can be used in conjunction with net2’s UdpBuilder interface to configure a socket before it’s handed off, such as setting options like reuse_address or binding to multiple addresses.

Use Handle::default() to lazily bind to an event loop, just like bind does.

pub fn local_addr(&self) -> Result<SocketAddr, Error>

Returns the local address that this socket is bound to.

pub fn connect(&self, addr: &SocketAddr) -> Result<(), Error>

Connects the UDP socket setting the default destination for send() and limiting packets that are read via recv from the address specified in addr.

pub fn poll_send(&mut self, buf: &[u8]) -> Result<Async<usize>, Error>

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.

Return

On success, returns Ok(Async::Ready(num_bytes_written)).

If the socket is not ready for writing, the method returns Ok(Async::NotReady) and arranges for the current task to receive a notification when the socket becomes writable.

Panics

This function will panic if called from outside of a task context.

pub fn poll_recv(&mut self, buf: &mut [u8]) -> Result<Async<usize>, Error>

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.

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

Return

On success, returns Ok(Async::Ready(num_bytes_read)).

If no data is available for reading, the method returns Ok(Async::NotReady) and arranges for the current task to receive a notification when the socket becomes receivable or is closed.

Panics

This function will panic if called from outside of a task context.

pub fn poll_send_to(
    &mut self,
    buf: &[u8],
    target: &SocketAddr
) -> Result<Async<usize>, Error>

Sends data on the socket to the given address. On success, returns the number of bytes written.

This will return an error when the IP version of the local socket does not match that of target.

Return

On success, returns Ok(Async::Ready(num_bytes_written)).

If the socket is not ready for writing, the method returns Ok(Async::NotReady) and arranges for the current task to receive a notification when the socket becomes writable.

Panics

This function will panic if called from outside of a task context.

pub fn send_dgram<T>(self, buf: T, addr: &SocketAddr) -> SendDgram<T>where
    T: AsRef<[u8]>,

Creates a future that will write the entire contents of the buffer buf provided as a datagram to this socket.

The returned future will return after data has been written to the outbound socket. The future will resolve to the stream as well as the buffer (for reuse if needed).

Any error which happens during writing will cause both the stream and the buffer to get destroyed. Note that failure to write the entire buffer is considered an error for the purposes of sending a datagram.

The buf parameter here only requires the AsRef<[u8]> trait, which should be broadly applicable to accepting data which can be converted to a slice.

pub fn poll_recv_from(
    &mut self,
    buf: &mut [u8]
) -> Result<Async<(usize, SocketAddr)>, Error>

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

Panics

This function will panic if called outside the context of a future’s task.

pub fn recv_dgram<T>(self, buf: T) -> RecvDgram<T>where
    T: AsMut<[u8]>,

Creates a future that receive a datagram to be written to the buffer provided.

The returned future will return after a datagram has been received on this socket. The future will resolve to the socket, the buffer, the amount of data read, and the address the data was received from.

An error during reading will cause the socket and buffer to get destroyed.

The buf parameter here only requires the AsMut<[u8]> trait, which should be broadly applicable to accepting data which can be converted to a slice.

pub fn poll_read_ready(&self, mask: Ready) -> Result<Async<Ready>, Error>

Check the UDP socket’s read readiness state.

The mask argument allows specifying what readiness to notify on. This can be any value, including platform specific readiness, except writable.

If the socket is not ready for receiving then Async::NotReady is returned and the current task is notified once a new event is received.

The socket will remain in a read-ready state until calls to poll_recv return NotReady.

Panics

This function panics if:

• ready includes writable.
• called from outside of a task context.

pub fn poll_write_ready(&self) -> Result<Async<Ready>, Error>

Check the UDP socket’s write readiness state.

If the socket is not ready for sending then Async::NotReady is returned and the current task is notified once a new event is received.

The I/O resource will remain in a write-ready state until calls to poll_send return NotReady.

Panics

This function panics if called from outside of a task context.

pub fn broadcast(&self) -> Result<bool, Error>

Gets the value of the SO_BROADCAST option for this socket.

For more information about this option, see set_broadcast.

pub fn set_broadcast(&self, on: bool) -> Result<(), Error>

Sets the value of the SO_BROADCAST option for this socket.

When enabled, this socket is allowed to send packets to a broadcast address.

pub fn multicast_loop_v4(&self) -> Result<bool, Error>

Gets the value of the IP_MULTICAST_LOOP option for this socket.

For more information about this option, see set_multicast_loop_v4.

pub fn set_multicast_loop_v4(&self, on: bool) -> Result<(), Error>

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

This may not have any affect on IPv6 sockets.

pub fn multicast_ttl_v4(&self) -> Result<u32, Error>

Gets the value of the IP_MULTICAST_TTL option for this socket.

For more information about this option, see set_multicast_ttl_v4.

pub fn set_multicast_ttl_v4(&self, ttl: u32) -> Result<(), Error>

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

This may not have any affect on IPv6 sockets.

pub fn multicast_loop_v6(&self) -> Result<bool, Error>

Gets the value of the IPV6_MULTICAST_LOOP option for this socket.

For more information about this option, see set_multicast_loop_v6.

pub fn set_multicast_loop_v6(&self, on: bool) -> Result<(), Error>

Sets the value of the IPV6_MULTICAST_LOOP option for this socket.

Controls whether this socket sees the multicast packets it sends itself.

Note

This may not have any affect on IPv4 sockets.

pub fn ttl(&self) -> Result<u32, Error>

Gets the value of the IP_TTL option for this socket.

For more information about this option, see set_ttl.

pub fn set_ttl(&self, ttl: u32) -> Result<(), Error>

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.

pub fn join_multicast_v4(
    &self,
    multiaddr: &Ipv4Addr,
    interface: &Ipv4Addr
) -> Result<(), Error>

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.

pub fn join_multicast_v6(
    &self,
    multiaddr: &Ipv6Addr,
    interface: u32
) -> Result<(), Error>

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).

pub fn leave_multicast_v4(
    &self,
    multiaddr: &Ipv4Addr,
    interface: &Ipv4Addr
) -> Result<(), Error>

Executes an operation of the IP_DROP_MEMBERSHIP type.

For more information about this option, see join_multicast_v4.

pub fn leave_multicast_v6(
    &self,
    multiaddr: &Ipv6Addr,
    interface: u32
) -> Result<(), Error>

Executes an operation of the IPV6_DROP_MEMBERSHIP type.

For more information about this option, see join_multicast_v6.

Trait Implementations

impl AsRawFd for UdpSocket

fn as_raw_fd(&self) -> i32

Extracts the raw file descriptor.

impl Debug for UdpSocket

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.