|  | // +build go1.6, !go1.8 | 
|  |  | 
|  | /* | 
|  | * | 
|  | * Copyright 2017 gRPC authors. | 
|  | * | 
|  | * Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | * you may not use this file except in compliance with the License. | 
|  | * You may obtain a copy of the License at | 
|  | * | 
|  | *     http://www.apache.org/licenses/LICENSE-2.0 | 
|  | * | 
|  | * Unless required by applicable law or agreed to in writing, software | 
|  | * distributed under the License is distributed on an "AS IS" BASIS, | 
|  | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | * See the License for the specific language governing permissions and | 
|  | * limitations under the License. | 
|  | * | 
|  | */ | 
|  |  | 
|  | package dns | 
|  |  | 
|  | import ( | 
|  | "fmt" | 
|  | "net" | 
|  |  | 
|  | "golang.org/x/net/context" | 
|  | ) | 
|  |  | 
|  | var errForInvalidTarget = fmt.Errorf("invalid target address [2001:db8:a0b:12f0::1, error info: missing ']' in address [2001:db8:a0b:12f0::1:443") | 
|  |  | 
|  | func replaceNetFunc() func() { | 
|  | oldLookupHost := lookupHost | 
|  | oldLookupSRV := lookupSRV | 
|  | oldLookupTXT := lookupTXT | 
|  | lookupHost = func(ctx context.Context, host string) ([]string, error) { | 
|  | return hostLookup(host) | 
|  | } | 
|  | lookupSRV = func(ctx context.Context, service, proto, name string) (string, []*net.SRV, error) { | 
|  | return srvLookup(service, proto, name) | 
|  | } | 
|  | lookupTXT = func(ctx context.Context, host string) ([]string, error) { | 
|  | return txtLookup(host) | 
|  | } | 
|  | return func() { | 
|  | lookupHost = oldLookupHost | 
|  | lookupSRV = oldLookupSRV | 
|  | lookupTXT = oldLookupTXT | 
|  | } | 
|  | } |