WIP: middleware/dnstap (#711)

middleware/dnstap add

vendor/github.com/dnstap/golang-dnstap/FrameStreamOutput.go

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2014 by Farsight Security, Inc.
+ *
+ * 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 dnstap
+
+import (
+	"io"
+	"log"
+	"os"
+
+	"github.com/farsightsec/golang-framestream"
+)
+
+type FrameStreamOutput struct {
+	outputChannel chan []byte
+	wait          chan bool
+	enc           *framestream.Encoder
+}
+
+func NewFrameStreamOutput(w io.Writer) (o *FrameStreamOutput, err error) {
+	o = new(FrameStreamOutput)
+	o.outputChannel = make(chan []byte, outputChannelSize)
+	o.enc, err = framestream.NewEncoder(w, &framestream.EncoderOptions{ContentType: FSContentType})
+	if err != nil {
+		return
+	}
+	o.wait = make(chan bool)
+	return
+}
+
+func NewFrameStreamOutputFromFilename(fname string) (o *FrameStreamOutput, err error) {
+	if fname == "" || fname == "-" {
+		return NewFrameStreamOutput(os.Stdout)
+	}
+	w, err := os.Create(fname)
+	if err != nil {
+		return
+	}
+	return NewFrameStreamOutput(w)
+}
+
+func (o *FrameStreamOutput) GetOutputChannel() chan []byte {
+	return o.outputChannel
+}
+
+func (o *FrameStreamOutput) RunOutputLoop() {
+	for frame := range o.outputChannel {
+		if _, err := o.enc.Write(frame); err != nil {
+			log.Fatalf("framestream.Encoder.Write() failed: %s\n", err)
+			break
+		}
+	}
+	close(o.wait)
+}
+
+func (o *FrameStreamOutput) Close() {
+	close(o.outputChannel)
+	<-o.wait
+	o.enc.Flush()
+	o.enc.Close()
+}