Struct SendAncillaryBuffer

pub struct SendAncillaryBuffer<'buf, 'slice, 'fd> {
    buffer: &'buf mut [MaybeUninit<u8>],
    length: usize,
    _phantom: PhantomData<&'slice [BorrowedFd<'fd>]>,
}

Buffer for sending ancillary messages with sendmsg and sendmsg_addr.

Use the push function to add messages to send.

Fields

buffer: &'buf mut [MaybeUninit<u8>]

Raw byte buffer for messages.

length: usize

The amount of the buffer that is used.

_phantom: PhantomData<&'slice [BorrowedFd<'fd>]>

Phantom data for lifetime of &'slice [BorrowedFd<'fd>].

Implementations

impl<'buf, 'slice, 'fd> SendAncillaryBuffer<'buf, 'slice, 'fd>

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

Create a new, empty SendAncillaryBuffer from a raw byte buffer.

The buffer size may be computed with cmsg_space, or it may be zero for an empty buffer, however in that case, consider default() instead, or even using send instead of sendmsg.

Examples

Allocate a buffer for a single file descriptor:

let mut space = [MaybeUninit::uninit(); rustix::cmsg_space!(ScmRights(1))];
let mut cmsg_buffer = SendAncillaryBuffer::new(&mut space);

Allocate a buffer for credentials:

let mut space = [MaybeUninit::uninit(); rustix::cmsg_space!(ScmCredentials(1))];
let mut cmsg_buffer = SendAncillaryBuffer::new(&mut space);

Allocate a buffer for two file descriptors and credentials:

let mut space = [MaybeUninit::uninit(); rustix::cmsg_space!(ScmRights(2), ScmCredentials(1))];
let mut cmsg_buffer = SendAncillaryBuffer::new(&mut space);

pub(crate) fn as_control_ptr(&mut self) -> *mut u8

Returns a pointer to the message data.

pub(crate) fn control_len(&self) -> usize

Returns the length of the message data.

pub fn clear(&mut self)

Delete all messages from the buffer.

pub fn push(&mut self, msg: SendAncillaryMessage<'slice, 'fd>) -> bool

Add an ancillary message to the buffer.

Returns true if the message was added successfully.

fn push_ancillary( &mut self, source: &[u8], cmsg_level: c_int, cmsg_type: c_int, ) -> bool

Pushes an ancillary message to the buffer.

Trait Implementations

impl Default for SendAncillaryBuffer<'_, '_, '_>

fn default() -> Self

Returns the “default value” for a type.

impl<'slice, 'fd> Extend<SendAncillaryMessage<'slice, 'fd>> for SendAncillaryBuffer<'_, 'slice, 'fd>

fn extend<T: IntoIterator<Item = SendAncillaryMessage<'slice, 'fd>>>( &mut self, iter: T, )

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<'buf> From<&'buf mut [MaybeUninit<u8>]> for SendAncillaryBuffer<'buf, '_, '_>

fn from(buffer: &'buf mut [MaybeUninit<u8>]) -> Self

Converts to this type from the input type.