bacnet_network/router/
local_control.rs

1//! The router's own network-control consumer (#1175).
2//!
3//! Most network messages a router receives are for its routing table, and it
4//! handles them inline. A Reject-Message-To-Network addressed to the router
5//! itself also answers something the router's own side sent, so besides
6//! updating the table it goes to the opt-in stream that
7//! [`RouterOptions::network_control_receiver`](super::RouterOptions::network_control_receiver)
8//! asks for. Its records are the [`ReceivedNetworkControl`] a non-router
9//! [`NetworkLayer`](crate::layer::NetworkLayer) hands its own consumer.
10
11use std::sync::Arc;
12use std::sync::atomic::{AtomicU64, Ordering};
13
14use bacnet_encoding::npdu::Npdu;
15use bacnet_transport::port::ReceivedNpdu;
16
17use super::BACnetRouter;
18use crate::layer::{AdmissionSender, ReceivedNetworkControl, next_ingress_sequence};
19
20/// Where network controls addressed to this router go.
21#[derive(Default)]
22pub(super) struct LocalControl {
23    /// The opted-in consumer, if any.
24    tx: Option<AdmissionSender<ReceivedNetworkControl>>,
25    /// Source of [`ReceivedNetworkControl::ingress_sequence`].
26    ingress_sequence: Arc<AtomicU64>,
27}
28
29impl LocalControl {
30    pub(super) fn new(
31        tx: Option<AdmissionSender<ReceivedNetworkControl>>,
32        ingress_sequence: Arc<AtomicU64>,
33    ) -> Self {
34        Self {
35            tx,
36            ingress_sequence,
37        }
38    }
39
40    /// Whether a consumer asked for these controls, so the dispatch reads
41    /// the control's header only for one.
42    pub(super) fn wanted(&self) -> bool {
43        self.tx.is_some()
44    }
45
46    /// Offer the control `received` carries to the consumer: `header` is
47    /// its control information, which the dispatch read from the engine's
48    /// view with [`Npdu::header_from`], and its data starts at `offset` in
49    /// the frame. The frame isn't decoded again, and the data shares its
50    /// buffer. Like the router's local APDU queue, a full or closed
51    /// consumer drops the arriving control and never holds up routing.
52    pub(super) fn deliver(&self, mut header: Npdu, offset: usize, received: &ReceivedNpdu) {
53        let Some(tx) = self.tx.as_ref() else {
54            return;
55        };
56        header.payload = received.npdu.slice(offset..);
57        let _ = tx.try_send(ReceivedNetworkControl {
58            npdu: header,
59            source_mac: received.source_mac.clone(),
60            link_layer_group: received.link_layer_group,
61            data_attributes: received.data_attributes.clone(),
62            provenance: received.provenance.clone(),
63            ingress_sequence: next_ingress_sequence(&self.ingress_sequence),
64        });
65    }
66}
67
68impl BACnetRouter {
69    /// Sequence assigned to the most recent control offered to the receiver
70    /// from [`RouterOptions::network_control_receiver`](super::RouterOptions::network_control_receiver)
71    /// or [`RouterOptions::network_control_receiver_with_admission`](super::RouterOptions::network_control_receiver_with_admission),
72    /// including one the receiver dropped. Saturates at `u64::MAX`.
73    pub fn network_control_ingress_sequence(&self) -> u64 {
74        self.network_control_ingress_sequence.load(Ordering::SeqCst)
75    }
76}
bacnet_network/router/local_control.rs

bacnet_network/router/
local_control.rs
