renet/src/socket/meta.rs

105 lines
3.3 KiB
Rust

use crate::socket::{PollAt, SocketHandle};
use crate::time::{Duration, Instant};
use crate::wire::IpAddress;
/// Neighbor dependency.
///
/// This enum tracks whether the socket should be polled based on the neighbor it is
/// going to send packets to.
#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
enum NeighborState {
/// Socket can be polled immediately.
Active,
/// Socket should not be polled until either `silent_until` passes or `neighbor` appears
/// in the neighbor cache.
Waiting {
neighbor: IpAddress,
silent_until: Instant,
},
}
impl Default for NeighborState {
fn default() -> Self {
NeighborState::Active
}
}
/// Network socket metadata.
///
/// This includes things that only external (to the socket, that is) code
/// is interested in, but which are more conveniently stored inside the socket itself.
#[derive(Debug, Default)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct Meta {
/// Handle of this socket within its enclosing `SocketSet`.
/// Mainly useful for debug output.
pub(crate) handle: SocketHandle,
/// See [NeighborState](struct.NeighborState.html).
neighbor_state: NeighborState,
}
impl Meta {
/// Minimum delay between neighbor discovery requests for this particular socket,
/// in milliseconds.
///
/// See also `iface::NeighborCache::SILENT_TIME`.
pub(crate) const DISCOVERY_SILENT_TIME: Duration = Duration { millis: 3_000 };
pub(crate) fn poll_at<F>(&self, socket_poll_at: PollAt, has_neighbor: F) -> PollAt
where
F: Fn(IpAddress) -> bool,
{
match self.neighbor_state {
NeighborState::Active => socket_poll_at,
NeighborState::Waiting { neighbor, .. } if has_neighbor(neighbor) => socket_poll_at,
NeighborState::Waiting { silent_until, .. } => PollAt::Time(silent_until),
}
}
pub(crate) fn egress_permitted<F>(&mut self, timestamp: Instant, has_neighbor: F) -> bool
where
F: Fn(IpAddress) -> bool,
{
match self.neighbor_state {
NeighborState::Active => true,
NeighborState::Waiting {
neighbor,
silent_until,
} => {
if has_neighbor(neighbor) {
net_trace!(
"{}: neighbor {} discovered, unsilencing",
self.handle,
neighbor
);
self.neighbor_state = NeighborState::Active;
true
} else if timestamp >= silent_until {
net_trace!(
"{}: neighbor {} silence timer expired, rediscovering",
self.handle,
neighbor
);
true
} else {
false
}
}
}
}
pub(crate) fn neighbor_missing(&mut self, timestamp: Instant, neighbor: IpAddress) {
net_trace!(
"{}: neighbor {} missing, silencing until t+{}",
self.handle,
neighbor,
Self::DISCOVERY_SILENT_TIME
);
self.neighbor_state = NeighborState::Waiting {
neighbor,
silent_until: timestamp + Self::DISCOVERY_SILENT_TIME,
};
}
}