Enum nix::sys::socket::ControlMessageOwned
source · #[non_exhaustive]pub enum ControlMessageOwned {
ScmRights(Vec<RawFd>),
ScmTimestamp(TimeVal),
RxqOvfl(u32),
}
Expand description
A type-safe wrapper around a single control message, as used with
recvmsg
.
Variants (Non-exhaustive)§
This enum is marked as 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(Vec<RawFd>)
Received version of ControlMessage::ScmRights
ScmTimestamp(TimeVal)
A message of type SCM_TIMESTAMP
, containing the time the
packet was received by the kernel.
See the kernel’s explanation in “SO_TIMESTAMP” of networking/timestamping.
§Examples
// Set up
let message = "Ohayō!".as_bytes();
let in_socket = socket(
AddressFamily::Inet,
SockType::Datagram,
SockFlag::empty(),
None).unwrap();
setsockopt(in_socket, sockopt::ReceiveTimestamp, &true).unwrap();
let localhost = SockaddrIn::from_str("127.0.0.1:0").unwrap();
bind(in_socket, &localhost).unwrap();
let address: SockaddrIn = getsockname(in_socket).unwrap();
// Get initial time
let time0 = SystemTime::now();
// Send the message
let iov = [IoSlice::new(message)];
let flags = MsgFlags::empty();
let l = sendmsg(in_socket, &iov, &[], flags, Some(&address)).unwrap();
assert_eq!(message.len(), l);
// Receive the message
let mut buffer = vec![0u8; message.len()];
let mut cmsgspace = cmsg_space!(TimeVal);
let mut iov = [IoSliceMut::new(&mut buffer)];
let r = recvmsg::<SockaddrIn>(in_socket, &mut iov, Some(&mut cmsgspace), flags)
.unwrap();
let rtime = match r.cmsgs().next() {
Some(ControlMessageOwned::ScmTimestamp(rtime)) => rtime,
Some(_) => panic!("Unexpected control message"),
None => panic!("No control message")
};
// Check the final time
let time1 = SystemTime::now();
// the packet's received timestamp should lie in-between the two system
// times, unless the system clock was adjusted in the meantime.
let rduration = Duration::new(rtime.tv_sec() as u64,
rtime.tv_usec() as u32 * 1000);
assert!(time0.duration_since(UNIX_EPOCH).unwrap() <= rduration);
assert!(rduration <= time1.duration_since(UNIX_EPOCH).unwrap());
// Close socket
nix::unistd::close(in_socket).unwrap();
RxqOvfl(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.
RxqOvfl
socket option should be enabled on a socket
to allow receiving the drop counter.
Trait Implementations§
source§impl Clone for ControlMessageOwned
impl Clone for ControlMessageOwned
source§fn clone(&self) -> ControlMessageOwned
fn clone(&self) -> ControlMessageOwned
Returns a copy of the value. Read more
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source
. Read moresource§impl Debug for ControlMessageOwned
impl Debug for ControlMessageOwned
source§impl PartialEq for ControlMessageOwned
impl PartialEq for ControlMessageOwned
source§fn eq(&self, other: &ControlMessageOwned) -> bool
fn eq(&self, other: &ControlMessageOwned) -> bool
This method tests for
self
and other
values to be equal, and is used
by ==
.impl Eq for ControlMessageOwned
impl StructuralPartialEq for ControlMessageOwned
Auto Trait Implementations§
impl Freeze for ControlMessageOwned
impl RefUnwindSafe for ControlMessageOwned
impl Send for ControlMessageOwned
impl Sync for ControlMessageOwned
impl Unpin for ControlMessageOwned
impl UnwindSafe for ControlMessageOwned
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
🔬This is a nightly-only experimental API. (
clone_to_uninit
)