[#315] netmap: Add maintenance mode network setting

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

netmap/network_info.go

@@ -75,7 +75,8 @@ func (x *NetworkInfo) readFromV2(m netmap.NetworkInfo, checkFieldPresence bool)
 			configMaxObjSize,
 			configWithdrawalFee:
 			_, err = decodeConfigValueUint64(prm.GetValue())
-		case configHomomorphicHashingDisabled:
+		case configHomomorphicHashingDisabled,
+			configMaintenanceModeAllowed:
 			_, err = decodeConfigValueBool(prm.GetValue())
 		}
 
@@ -247,7 +248,8 @@ func (x *NetworkInfo) IterateRawNetworkParameters(f func(name string, value []by
 			configIRCandidateFee,
 			configMaxObjSize,
 			configWithdrawalFee,
-			configHomomorphicHashingDisabled:
+			configHomomorphicHashingDisabled,
+			configMaintenanceModeAllowed:
 		}
 
 		return false
@@ -522,3 +524,20 @@ func (x *NetworkInfo) DisableHomomorphicHashing() {
 func (x NetworkInfo) HomomorphicHashingDisabled() bool {
 	return x.configBool(configHomomorphicHashingDisabled)
 }
+
+const configMaintenanceModeAllowed = "MaintenanceModeAllowed"
+
+// AllowMaintenanceMode sets the flag allowing nodes to go into maintenance mode.
+//
+// See also MaintenanceModeAllowed.
+func (x *NetworkInfo) AllowMaintenanceMode() {
+	x.setConfigBool(configMaintenanceModeAllowed, true)
+}
+
+// MaintenanceModeAllowed returns true iff network config allows
+// maintenance mode for storage nodes.
+//
+// Zero NetworkInfo has disallows maintenance mode.
+func (x NetworkInfo) MaintenanceModeAllowed() bool {
+	return x.configBool(configMaintenanceModeAllowed)
+}

netmap/network_info_test.go

@@ -233,3 +233,21 @@ func TestNetworkInfo_HomomorphicHashingDisabled(t *testing.T) {
 		},
 	)
 }
+
+func TestNetworkInfo_MaintenanceModeAllowed(t *testing.T) {
+	testConfigValue(t,
+		func(x NetworkInfo) interface{} { return x.MaintenanceModeAllowed() },
+		func(info *NetworkInfo, val interface{}) {
+			if val.(bool) {
+				info.AllowMaintenanceMode()
+			}
+		},
+		true, true,
+		"MaintenanceModeAllowed", func(val interface{}) []byte {
+			if val.(bool) {
+				return []byte{1}
+			}
+			return []byte{0}
+		},
+	)
+}