add helpers on Host for v2

explorer/scan.go

@@ -81,7 +81,6 @@ func (e *Explorer) scanV1Host(locator geoip.Locator, host Host) (HostScan, error
 	}
 
 	resolved, err := net.ResolveIPAddr("ip", hostIP)
-	// if we can resolve the address
 	if err != nil {
 		return HostScan{}, fmt.Errorf("scanHost: failed to resolve host address: %w", err)
 	}
@@ -118,7 +117,11 @@ func (e *Explorer) scanV2Host(locator geoip.Locator, host Host) (HostScan, error
 	ctx, cancel := context.WithTimeout(e.ctx, e.scanCfg.Timeout)
 	defer cancel()
 
-	addr := host.V2NetAddresses[0].Address
+	addr, ok := host.V2SiamuxAddr()
+	if !ok {
+		return HostScan{}, fmt.Errorf("host has no v2 siamux address")
+	}
+
 	transport, err := crhpv4.DialSiaMux(ctx, addr, host.PublicKey)
 	if err != nil {
 		return HostScan{}, fmt.Errorf("failed to dial host: %w", err)
@@ -136,7 +139,6 @@ func (e *Explorer) scanV2Host(locator geoip.Locator, host Host) (HostScan, error
 	}
 
 	resolved, err := net.ResolveIPAddr("ip", hostIP)
-	// if we can resolve the address
 	if err != nil {
 		return HostScan{}, fmt.Errorf("scanHost: failed to resolve host address: %w", err)
 	}
@@ -175,13 +177,19 @@ func (e *Explorer) addHostScans(hosts chan Host) {
 
 			var scan HostScan
 			var addr string
+			var ok bool
 			var err error
-			if len(host.V2NetAddresses) == 0 {
-				addr = host.NetAddress
-				scan, err = e.scanV1Host(locator, host)
+
+			if host.IsV2() {
+				addr, ok = host.V2SiamuxAddr()
+				if !ok {
+					e.log.Debug("Host did not have any v2 siamux net addresses in its announcement, unable to scan", zap.Stringer("pk", host.PublicKey))
+					continue
+				} else {
+					scan, err = e.scanV2Host(locator, host)
+				}
 			} else {
-				addr = host.V2NetAddresses[0].Address
-				scan, err = e.scanV2Host(locator, host)
+				scan, err = e.scanV1Host(locator, host)
 			}
 			if err != nil {
 				scans = append(scans, HostScan{

explorer/types.go

@@ -11,6 +11,7 @@ import (
 	rhpv4 "go.sia.tech/core/rhp/v4"
 	"go.sia.tech/core/types"
 	"go.sia.tech/coreutils/chain"
+	crhpv4 "go.sia.tech/coreutils/rhp/v4"
 )
 
 // A Source represents where a siacoin output came from.
@@ -336,6 +337,23 @@ type Host struct {
 	RHPV4Settings rhpv4.HostSettings `json:"rhpV4Settings"`
 }
 
+// V2SiaMuxAddr returns the `Address` of the first TCP siamux `NetAddress` it
+// finds in the host's list of net addresses.  The protocol for this address is
+// ProtocolTCPSiaMux.
+func (h Host) V2SiamuxAddr() (string, bool) {
+	for _, netAddr := range h.V2NetAddresses {
+		if netAddr.Protocol == crhpv4.ProtocolTCPSiaMux {
+			return netAddr.Address, true
+		}
+	}
+	return "", false
+}
+
+// IsV2 returns whether a host supports V2 or not.
+func (h Host) IsV2() bool {
+	return len(h.V2NetAddresses) > 0
+}
+
 // HostMetrics represents averages of scanned information from hosts.
 type HostMetrics struct {
 	ActiveHosts uint64               `json:"activeHosts"`