break
			}
		}
	}

	cname, err := LookupCNAME("www.mit.edu")
	if err != nil {
		t.Errorf("LookupCNAME(www.mit.edu, mode=%v): %v", mode, err)
	} else if !strings.HasSuffix(cname, ".") {
		t.Errorf("LookupCNAME(www.mit.edu) = %v, want cname ending in . with trailing dot (mode=%v)", cname, mode)
	}

	mxs, err := LookupMX("google.com")

		s = s[i+1:] // remove address
	}
	if n, _, ok := dtoi(s); ok {
		return n, nil
	}
	return 0, &DNSError{Err: "unknown port", Name: errNetwork + "/" + service, IsNotFound: true}
}

func (r *Resolver) lookupCNAME(ctx context.Context, name string) (cname string, err error) {
	if order, conf := systemConf().hostLookupOrder(r, name); order != hostLookupCgo {
		return r.goLookupCNAME(ctx, name, order, conf)
	}

		}
	})
}

func TestNSLookupCNAME(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	testLookup(t, func(t *testing.T, r *Resolver, server string) {
		cname, err := r.LookupCNAME(context.Background(), server)
		if err != nil {
			t.Fatalf("failed %s: %s", server, err)
		}
		if cname == "" {
			t.Fatalf("no result %s", server)
		}
		expected, err := nslookupCNAME(server)
		if err != nil {

	case syscall.AF_INET6:
		a := (*syscall.RawSockaddrInet6)(addr)
		return int(syscall.Ntohs(a.Port)), nil
	}
	return 0, newDNSError(syscall.EINVAL, network+"/"+service, "")
}

func (r *Resolver) lookupCNAME(ctx context.Context, name string) (string, error) {
	if order, conf := systemConf().hostLookupOrder(r, name); order != hostLookupCgo {
		return r.goLookupCNAME(ctx, name, order, conf)
	}

pkg net, method (*Buffers) Read([]uint8) (int, error)
pkg net, method (*Buffers) WriteTo(io.Writer) (int64, error)
pkg net, method (*Resolver) LookupAddr(context.Context, string) ([]string, error)
pkg net, method (*Resolver) LookupCNAME(context.Context, string) (string, error)
pkg net, method (*Resolver) LookupHost(context.Context, string) ([]string, error)
pkg net, method (*Resolver) LookupIPAddr(context.Context, string) ([]IPAddr, error)

			f: func(t *testing.T) {
				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "golang.org"}
				_, err := r.LookupCNAME(context.Background(), "golang.org")
				if err.Error() != expectedErr.Error() {
					t.Fatalf("unexpected error: %s", err)
				}
				_, err = LookupCNAME("golang.org")
				if err.Error() != expectedErr.Error() {
					t.Fatalf("unexpected error: %s", err)
				}
			},
		},

			}
		}
		if lastErr != nil {
			return nil, dnsmessage.Name{}, lastErr
		}
	}
	return addrs, cname, nil
}

// goLookupCNAME is the native Go (non-cgo) implementation of LookupCNAME.
func (r *Resolver) goLookupCNAME(ctx context.Context, host string, order hostLookupOrder, conf *dnsConfig) (string, error) {
	_, cname, err := r.goLookupIPCNAMEOrder(ctx, "CNAME", host, order, conf)
	return cname.String(), err

		{"(*ParseError).Error", Method, 0},
		{"(*ParseError).Temporary", Method, 17},
		{"(*ParseError).Timeout", Method, 17},
		{"(*Resolver).LookupAddr", Method, 8},
		{"(*Resolver).LookupCNAME", Method, 8},
		{"(*Resolver).LookupHost", Method, 8},
		{"(*Resolver).LookupIP", Method, 15},
		{"(*Resolver).LookupIPAddr", Method, 8},
		{"(*Resolver).LookupMX", Method, 8},

pkg net, func ListenUnix(string, *UnixAddr) (*UnixListener, error)
pkg net, func ListenUnixgram(string, *UnixAddr) (*UDPConn, error)
pkg net, func LookupAddr(string) ([]string, error)
pkg net, func LookupCNAME(string) (string, error)
pkg net, func LookupHost(string) ([]string, error)
pkg net, func LookupIP(string) ([]IP, error)
pkg net, func LookupMX(string) ([]*MX, error)
pkg net, func LookupPort(string, string) (int, error)