Struct vmm_vhost::connection::Connection

pub struct Connection<R: Req>(pub(crate) PlatformConnection, pub(crate) PhantomData<R>, pub(crate) PhantomData<Cell<()>>);

A vhost-user connection at a low abstraction level. Provides methods for sending and receiving vhost-user message headers and bodies.

Builds on top of PlatformConnection, which provides methods for sending and receiving raw bytes and file descriptors (a thin cross-platform abstraction for unix domain sockets).

Tuple Fields

0: PlatformConnection

1: PhantomData<R>

2: PhantomData<Cell<()>>

Implementations

impl<R: Req> Connection<R>

pub fn send_header_only_message( &self, hdr: &VhostUserMsgHeader<R>, fds: Option<&[RawDescriptor]> ) -> Result<()>

Sends a header-only message with optional attached file descriptors.

pub fn send_message<T: AsBytes>( &self, hdr: &VhostUserMsgHeader<R>, body: &T, fds: Option<&[RawDescriptor]> ) -> Result<()>

Send a message with header and body. Optional file descriptors may be attached to the message.

pub fn send_message_with_payload<T: Sized + AsBytes>( &self, hdr: &VhostUserMsgHeader<R>, body: &T, payload: &[u8], fds: Option<&[RawDescriptor]> ) -> Result<()>

Send a message with header and body. payload is appended to the end of the body. Optional file descriptors may also be attached to the message.

fn recv_into_bufs_all(&self, bufs: &mut [&mut [u8]]) -> Result<Vec<File>>

Reads all bytes into the given scatter/gather vectors with optional attached files. Will loop until all data has been transfered and errors if EOF is reached before then.

Return:

• • received fds on success
• • Disconnect - client is closed

TODO

This function takes a slice of &mut [u8] instead of IoSliceMut because the internal cursor needs to be moved by advance_slices_mut(). Once IoSliceMut::advance_slices() becomes stable, this should be updated. https://github.com/rust-lang/rust/issues/62726.

pub fn recv_header(&self) -> Result<(VhostUserMsgHeader<R>, Vec<File>)>

Receive message header

Errors if the header is invalid.

Note, only the first MAX_ATTACHED_FD_ENTRIES file descriptors will be accepted and all other file descriptor will be discard silently.

pub fn recv_body_bytes(&self, hdr: &VhostUserMsgHeader<R>) -> Result<Vec<u8>>

Receive the body following the header hdr.

pub fn recv_message<T: AsBytes + FromBytes + VhostUserMsgValidator>( &self ) -> Result<(VhostUserMsgHeader<R>, T, Vec<File>)>

Receive a message header and body.

Errors if the header or body is invalid.

Note, only the first MAX_ATTACHED_FD_ENTRIES file descriptors will be accepted and all other file descriptor will be discard silently.

pub fn recv_message_with_payload<T: AsBytes + FromBytes + VhostUserMsgValidator>( &self ) -> Result<(VhostUserMsgHeader<R>, T, Vec<u8>, Vec<File>)>

Receive a message header and body, where the body includes a variable length payload at the end.

Errors if the header or body is invalid.

Note, only the first MAX_ATTACHED_FD_ENTRIES file descriptors will be accepted and all other file descriptor will be discard silently.

impl<R: Req> Connection<R>

pub fn pair() -> Result<(Self, Self)>

Create a pair of unnamed vhost-user connections connected to each other.

Trait Implementations

impl<R: Req> AsRawDescriptor for Connection<R>

fn as_raw_descriptor(&self) -> RawDescriptor

Returns the underlying raw descriptor.

impl<R: Req> TryFrom<SafeDescriptor> for Connection<R>

type Error = Error

The type returned in the event of a conversion error.

fn try_from(fd: SafeDescriptor) -> Result<Self>

Performs the conversion.

impl<R: Req> TryFrom<UnixStream> for Connection<R>

type Error = Error

The type returned in the event of a conversion error.

fn try_from(sock: UnixStream) -> Result<Self>

Performs the conversion.