neon/udp

Types

OpenOptions

opaque </>

Options for opening a UDP socket.

Create with new, then optionally configure with ip_address and ip_version before passing to open.

pub opaque type OpenOptions

ReceiveData

</>

Data received from a UDP socket, including the sender’s IP address, port, and the payload.

pub type ReceiveData {
  ReceiveData(
    ip_address: net.IpAddress,
    port: net.Port,
    payload: BitArray,
  )
}

Constructors

ReceiveData(
  ip_address: net.IpAddress,
  port: net.Port,
  payload: BitArray,
)

Udp

</>

A UDP socket.

pub type Udp

UdpError

</>

Errors that can occur during UDP operations.

pub type UdpError {
  Closed
  Timeout
  SystemLimit
  Posix(net.Posix)
  InvalidPid
  UdpError(String)
}

Constructors

```
Closed
```
The socket was closed.
```
Timeout
```
The operation timed out.
```
SystemLimit
```
The Erlang VM can’t allocate more resources for network operations.
```
Posix(net.Posix)
```
A POSIX error.
```
InvalidPid
```
The target pid is not alive.
```
UdpError(String)
```
A generic UDP error with a description.

Values

close

</>

pub fn close(socket: Udp) -> Nil

Closes a UDP socket.

This function is idempotent and always returns Nil.

connect

</>

pub fn connect(
  socket: Udp,
  address: net.Address,
  port: net.Port,
) -> Result(Nil, UdpError)

Associates a UDP socket with a remote address and port.

After connecting, send can be used without specifying a destination.

controlling_process

</>

pub fn controlling_process(
  socket: Udp,
  pid: process.Pid,
) -> Result(Nil, UdpError)

Change the controlling process of a socket.

The controlling process is the process that the socket sends messages to.

ip_address

</>

pub fn ip_address(
  opts: OpenOptions,
  ip_address: net.IpAddress,
) -> OpenOptions

Binds the socket to a specific IP address.

When set, the IP version is derived from the address itself, and the ip_version option is ignored.

ip_version

</>

pub fn ip_version(
  opts: OpenOptions,
  ip_version: net.IpVersion,
) -> OpenOptions

Sets the IP version for the socket.

Only used when no IP address is set. When an IP address is provided, the version is derived from the address.

new

</>

pub fn new(port: net.Port) -> OpenOptions

Creates open options for a UDP socket on the given port.

Defaults to IPv4 with no specific IP address binding.

open

</>

pub fn open(opts: OpenOptions) -> Result(Udp, UdpError)

Opens a UDP socket with the given options.

port

</>

pub fn port(socket: Udp) -> Result(net.Port, Nil)

Returns the port number assigned to a socket by the operating system.

Useful when opening on port 0 (OS-assigned).

receive

</>

pub fn receive(
  socket: Udp,
  length: Int,
  timeout: net.Timeout,
) -> Result(ReceiveData, UdpError)

Receives data from a UDP socket.

The length parameter specifies the number of bytes to receive. Use 0 to receive whatever data is available. Must be non-negative.

send

</>

pub fn send(
  socket: Udp,
  payload: BitArray,
) -> Result(Nil, UdpError)

Sends data over a connected UDP socket.