Trait FlowExtractor 

pub trait FlowExtractor:
    Send
    + Sync
    + 'static {
    type Key: Eq + Hash + Clone + Send + Sync + 'static;

    // Required method
    fn extract(&self, view: PacketView<'_>) -> Option<Extracted<Self::Key>>;
}

Extract a flow descriptor from one packet.

Implementations are called once per packet on the hot path — keep them cheap and stateless. Most return Some(_); malformed, non-IP, or out-of-scope packets return None and are skipped.

Bidirectional flows

If you want A→B and B→A merged into one flow, your extractor must produce the same Key for both orientations and report each packet’s direction via Extracted::orientation. The built-in crate::extract::FiveTuple::bidirectional does this by sorting (addr, port) pairs.

Bounds

Send + Sync + 'static is required so a tracker generic over this trait can be used from any task / thread.

Required Associated Types

type Key: Eq + Hash + Clone + Send + Sync + 'static

The flow key. Equality + hashability identify the flow.

Required Methods

fn extract(&self, view: PacketView<'_>) -> Option<Extracted<Self::Key>>

Extract a flow descriptor from view.

Returns None if this packet is not part of any flow you want to track (skipped, malformed, encap-only, ARP, etc.).

Implementors

impl FlowExtractor for FiveTuple

Available on crate feature extractors only.

type Key = FiveTupleKey

impl FlowExtractor for IpPair

Available on crate feature extractors only.

type Key = IpPairKey

impl FlowExtractor for MacPair

Available on crate feature extractors only.

type Key = MacPairKey

impl<E> FlowExtractor for FlowLabel<E>

where E: FlowExtractor, E::Key: Hash + Eq + Clone + Send + Sync + 'static,

Available on crate feature extractors only.

type Key = FlowLabelKey<<E as FlowExtractor>::Key>

impl<E, H> FlowExtractor for DnsUdpObserver<E, H>

where E: FlowExtractor, H: DnsHandler, E::Key: Eq + Hash + Clone,

Available on crate feature dns only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor + Clone> FlowExtractor for AutoDetectEncap<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor> FlowExtractor for InnerGre<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor> FlowExtractor for InnerGtpU<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor> FlowExtractor for StripMpls<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor> FlowExtractor for StripVlan<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key

impl<E: FlowExtractor> FlowExtractor for InnerVxlan<E>

Available on crate feature extractors only.

type Key = <E as FlowExtractor>::Key