Peer Discovery

DiscoveryBackend trait, DiscoveryCoordinator, bootstrap peers, peer exchange, mDNS, Kademlia DHT, and DHT key namespacing.

WeftOS provides pluggable peer discovery through the DiscoveryBackend trait with cross-backend deduplication.

Source: crates/clawft-kernel/src/mesh_discovery.rs, mesh_bootstrap.rs, mesh_mdns.rs, mesh_kad.rs Feature: mesh

DiscoveryBackend Trait

#[async_trait]
pub trait DiscoveryBackend: Send + Sync {
    fn name(&self) -> &str;
    async fn start(&mut self) -> Result<(), DiscoveryError>;
    async fn poll(&mut self) -> Result<Vec<DiscoveredPeer>, DiscoveryError>;
    async fn stop(&mut self) -> Result<(), DiscoveryError>;
}

pub enum DiscoverySource { SeedPeer, PeerExchange, Mdns, Dht }

DiscoveryCoordinator

poll_all() queries all backends and deduplicates using node IDs.

Bootstrap Discovery

Reads ClusterConfig.seed_peers. Idempotent, zero dependencies.

Peer Exchange

Learns peers from JoinResponse.peer_list during handshake.

mDNS (LAN Discovery)

pub struct MdnsDiscovery { /* UDP multicast 224.0.0.251:5353 */ }
pub const WEFTOS_SERVICE_NAME: &str = "_weftos._tcp.local";

Announcements include governance genesis hash for cluster isolation.

Kademlia DHT

pub struct KademliaTable {
    local_id: DhtKey,
    buckets: Vec<Vec<DhtEntry>>,
}

pub const K_BUCKET_SIZE: usize = 20;
pub const ALPHA: usize = 3;
pub const KEY_BITS: usize = 256;

XOR distance metric: xor_distance(), leading_zeros(), bucket_index().

DHT Key Namespacing

pub struct NamespacedDhtKey {
    pub governance_genesis: String,
    pub key_type: String,
    pub key: String,
}
// Format: "{genesis_prefix}:{key_type}:{key}"

Prevents cross-cluster DHT pollution.