Refactor - now wireguard based. (#7)

peer/on_hub.go

@@ -0,0 +1,114 @@
+package peer
+
+import (
+	"log"
+	"math"
+	"net/netip"
+	"time"
+
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+
+	"vppn/m"
+	"vppn/peer/control"
+)
+
+func (a *App) onAddPeer(p m.Peer) {
+	a.onRemovePeer(p.WGPubKey)
+
+	octets := a.vpnNet.Addr().As4()
+	octets[3] = p.PeerIP
+	vpnIP := netip.AddrFrom4(octets)
+
+	peer := &Peer{
+		wgPeer:     wgtypes.Peer{PublicKey: p.WGPubKey},
+		VPNIP:      vpnIP,
+		Name:       p.Name,
+		IsRelay:    p.Relay,
+		IsPublic:   p.IsPublic(),
+		EndpointV4: p.Endpoint4(),
+		EndpointV6: p.Endpoint6(),
+		RTT:        time.Duration(math.MaxInt64) * time.Nanosecond,
+		Role:       roleFor(a.isPublic, a.vpnIP, p.IsPublic(), vpnIP),
+		SignPubKey: p.SignPubKey,
+	}
+
+	a.peersByKey[p.WGPubKey] = peer
+	a.peersByIP[peer.VPNIP] = peer
+	defer a.updateHosts()
+
+	if !peer.IsPublic {
+		if a.isPublic {
+			// Public nodes accept traffic from non-public peers as soon as they
+			// initiate a handshake. Set /32 AllowedIPs now; WireGuard learns the
+			// endpoint from the incoming handshake automatically.
+			a.devPromote(peer)
+		} else {
+			a.devAddPeer(peer)
+		}
+		return
+	}
+
+	a.devAddDirect(peer, peer.PreferredEndpoint())
+}
+
+func (a *App) onRemovePeer(key wgtypes.Key) {
+	peer, exists := a.peersByKey[key]
+	if !exists {
+		return
+	}
+	a.devRemove(peer)
+	delete(a.peersByKey, key)
+	delete(a.peersByIP, peer.VPNIP)
+	a.updateHosts()
+
+	if peer == a.relay {
+		a.relay = nil
+		a.switchActiveRelay()
+	}
+}
+
+// switchActiveRelay promotes the lowest-latency relay peer to active.
+func (a *App) switchActiveRelay() {
+	if a.relay != nil {
+		// If we have a relay, it's public, so should go back to being a direct
+		// peer - this will convert it's /24 to a /32.
+		a.devAddDirect(a.relay, a.relay.PreferredEndpoint())
+		a.relay = nil
+	}
+
+	var best *Peer
+	for _, p := range a.peersByKey {
+		if !p.CanRelay() {
+			continue
+		}
+
+		if best == nil || p.RTT < best.RTT {
+			best = p
+		}
+	}
+	if best == nil {
+		log.Printf("no relay available")
+		return
+	}
+
+	a.devSetRelay(best, best.PreferredEndpoint())
+	a.relay = best
+}
+
+func preferredEndpoint(v4, v6 netip.AddrPort) netip.AddrPort {
+	// We always prefer v4 since all peers can connect to IPv4 addresses.
+	if v4.IsValid() {
+		return v4
+	}
+	return v6
+}
+
+func roleFor(selfIsPublic bool, selfIP netip.Addr, peerIsPublic bool, peerVPNIP netip.Addr) control.Role {
+	if !selfIsPublic && peerIsPublic {
+		return control.Client
+	}
+	if selfIsPublic && !peerIsPublic {
+		return control.Server
+	}
+	return control.RoleFor(selfIP, peerVPNIP)
+}