Struct std::os::unix::net::ancillary::SocketAncillary

pub struct SocketAncillary<'a> {
    buffer: &'a mut [u8],
    length: usize,
    truncated: bool,
}

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Available on Unix and (Android or Linux) only.

A Unix socket Ancillary data struct.

Example

#![feature(unix_socket_ancillary_data)]
use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
use std::io::IoSliceMut;

fn main() -> std::io::Result<()> {
    let sock = UnixStream::connect("/tmp/sock")?;

    let mut fds = [0; 8];
    let mut ancillary_buffer = [0; 128];
    let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);

    let mut buf = [1; 8];
    let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];
    sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;

    for ancillary_result in ancillary.messages() {
        if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
            for fd in scm_rights {
                println!("receive file descriptor: {fd}");
            }
        }
    }
    Ok(())
}

Fields

buffer: &'a mut [u8]

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

length: usize

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

truncated: bool

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Implementations

impl<'a> SocketAncillary<'a>

pub fn new(buffer: &'a mut [u8]) -> Self

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Create an ancillary data with the given buffer.

Example

#![feature(unix_socket_ancillary_data)]
use std::os::unix::net::SocketAncillary;
let mut ancillary_buffer = [0; 128];
let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);

pub fn capacity(&self) -> usize

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Returns the capacity of the buffer.

pub fn is_empty(&self) -> bool

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Returns true if the ancillary data is empty.

pub fn len(&self) -> usize

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Returns the number of used bytes.

pub fn messages(&self) -> Messages<'_>

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Returns the iterator of the control messages.

pub fn truncated(&self) -> bool

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Is true if during a recv operation the ancillary was truncated.

Example

#![feature(unix_socket_ancillary_data)]
use std::os::unix::net::{UnixStream, SocketAncillary};
use std::io::IoSliceMut;

fn main() -> std::io::Result<()> {
    let sock = UnixStream::connect("/tmp/sock")?;

    let mut ancillary_buffer = [0; 128];
    let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);

    let mut buf = [1; 8];
    let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];
    sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;

    println!("Is truncated: {}", ancillary.truncated());
    Ok(())
}

pub fn add_fds(&mut self, fds: &[RawFd]) -> bool

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Add file descriptors to the ancillary data.

The function returns true if there was enough space in the buffer. If there was not enough space then no file descriptors was appended. Technically, that means this operation adds a control message with the level SOL_SOCKET and type SCM_RIGHTS.

Example

#![feature(unix_socket_ancillary_data)]
use std::os::unix::net::{UnixStream, SocketAncillary};
use std::os::unix::io::AsRawFd;
use std::io::IoSlice;

fn main() -> std::io::Result<()> {
    let sock = UnixStream::connect("/tmp/sock")?;

    let mut ancillary_buffer = [0; 128];
    let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
    ancillary.add_fds(&[sock.as_raw_fd()][..]);

    let buf = [1; 8];
    let mut bufs = &mut [IoSlice::new(&buf[..])][..];
    sock.send_vectored_with_ancillary(bufs, &mut ancillary)?;
    Ok(())
}

pub fn add_creds(&mut self, creds: &[SocketCred]) -> bool

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Add credentials to the ancillary data.

The function returns true if there is enough space in the buffer. If there is not enough space then no credentials will be appended. Technically, that means this operation adds a control message with the level SOL_SOCKET and type SCM_CREDENTIALS, SCM_CREDS, or SCM_CREDS2.

pub fn clear(&mut self)

🔬This is a nightly-only experimental API. (unix_socket_ancillary_data #76915)

Clears the ancillary data, removing all values.

Example

#![feature(unix_socket_ancillary_data)]
use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
use std::io::IoSliceMut;

fn main() -> std::io::Result<()> {
    let sock = UnixStream::connect("/tmp/sock")?;

    let mut fds1 = [0; 8];
    let mut fds2 = [0; 8];
    let mut ancillary_buffer = [0; 128];
    let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);

    let mut buf = [1; 8];
    let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];

    sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
    for ancillary_result in ancillary.messages() {
        if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
            for fd in scm_rights {
                println!("receive file descriptor: {fd}");
            }
        }
    }

    ancillary.clear();

    sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
    for ancillary_result in ancillary.messages() {
        if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
            for fd in scm_rights {
                println!("receive file descriptor: {fd}");
            }
        }
    }
    Ok(())
}

Trait Implementations

impl<'a> Debug for SocketAncillary<'a>

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

Formats the value using the given formatter.