wip: Try to match against IPv6 before falling back

pkg/hostagent/port.go

@@ -40,18 +40,39 @@ func hostAddress(rule limayaml.PortForward, guest api.IPPort) string {
 	return host.String()
 }
 
+func tcpRuleIsWithinBounds(guest api.IPPort, rule limayaml.PortForward) bool {
+	if rule.GuestSocket != "" {
+		// Not TCP
+		return false
+	}
+
+	// Check if `guest.Port` is within `rule.GuestPortRange`
+	return guest.Port >= rule.GuestPortRange[0] && guest.Port <= rule.GuestPortRange[1]
+}
+
 func (pf *portForwarder) forwardingAddresses(guest api.IPPort) (hostAddr string, guestAddr string) {
+	// Check if it matches new IPv6 rule, otherwise fallback to the pre-IPv6 checks to maintain
+	// compatibility
 	for _, rule := range pf.rules {
-		if rule.GuestSocket != "" {
+		if !tcpRuleIsWithinBounds(guest, rule) {
 			continue
 		}
-		if guest.Port < rule.GuestPortRange[0] || guest.Port > rule.GuestPortRange[1] {
+
+		// guest.IP and HostIP must be either :: or 0.0.0.0, and be forwarded to the same family on HostIP
+		if guest.IP.IsUnspecified() && rule.HostIP.IsUnspecified() && ((guest.IP.To4() == nil) == (rule.HostIP.To4() == nil)) {
+			return hostAddress(rule, guest), guest.String()
+		}
+	}
+
+	// Before giving up, try to match against the old rule set
+	for _, rule := range pf.rules {
+		if !tcpRuleIsWithinBounds(guest, rule) {
 			continue
 		}
 
 		switch {
+		case guest.IP.IsUnspecified():
 		case guest.IP.Equal(rule.GuestIP):
-		case guest.IP.IsUnspecified() && rule.GuestIP.IsUnspecified() && ((guest.IP.To4() == nil) == (rule.HostIP.To4() == nil)):
 		case guest.IP.Equal(net.IPv6loopback) && rule.GuestIP.Equal(api.IPv4loopback1):
 		case rule.GuestIP.IsUnspecified() && !rule.GuestIPMustBeZero:
 			// When GuestIPMustBeZero is true, then 0.0.0.0 must be an exact match, which is already
@@ -67,6 +88,7 @@ func (pf *portForwarder) forwardingAddresses(guest api.IPPort) (hostAddr string,
 		}
 		return hostAddress(rule, guest), guest.String()
 	}
+
 	return "", guest.String()
 }