Enum ControlMessage

#[non_exhaustive]
pub enum ControlMessage<'a> {
    ScmRights(&'a [RawFd]),
    RxqOvfl(&'a u32),
}

A type-safe zero-copy wrapper around a single control message, as used with sendmsg. More types may be added to this enum; do not exhaustively pattern-match it.

Further reading

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

ScmRights(&'a [RawFd])

A message of type SCM_RIGHTS, containing an array of file descriptors passed between processes.

See the description in the “Ancillary messages” section of the unix(7) man page.

Using multiple ScmRights messages for a single sendmsg call isn’t recommended since it causes platform-dependent behaviour: It might swallow all but the first ScmRights message or fail with EINVAL. Instead, you can put all fds to be passed into a single ScmRights message.

RxqOvfl(&'a u32)

SO_RXQ_OVFL indicates that an unsigned 32 bit value ancilliary msg (cmsg) should be attached to recieved skbs indicating the number of packets dropped by the socket between the last recieved packet and this received packet.

Trait Implementations

impl<'a> Clone for ControlMessage<'a>

fn clone(&self) -> ControlMessage<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for ControlMessage<'a>

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

Formats the value using the given formatter.

impl<'a> PartialEq for ControlMessage<'a>

fn eq(&self, other: &ControlMessage<'a>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> Copy for ControlMessage<'a>

impl<'a> Eq for ControlMessage<'a>

impl<'a> StructuralPartialEq for ControlMessage<'a>