feat: add vendor

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

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2013-2019 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"
+	"os"
+	"time"
+)
+
+// MaxPayloadSize sets the upper limit on input Dnstap payload sizes. If an Input
+// receives a Dnstap payload over this size limit, ReadInto will log an error and
+// return.
+//
+// EDNS0 and DNS over TCP use 2 octets for DNS message size, imposing a maximum
+// size of 65535 octets for the DNS message, which is the bulk of the data carried
+// in a Dnstap message. Protobuf encoding overhead and metadata with some size
+// guidance (e.g., identity and version being DNS strings, which have a maximum
+// length of 255) add up to less than 1KB. The default 96KiB size of the buffer
+// allows a bit over 30KB space for "extra" metadata.
+//
+var MaxPayloadSize uint32 = 96 * 1024
+
+// A FrameStreamInput reads dnstap data from an io.ReadWriter.
+type FrameStreamInput struct {
+	wait   chan bool
+	reader Reader
+	log    Logger
+}
+
+// NewFrameStreamInput creates a FrameStreamInput reading data from the given
+// io.ReadWriter. If bi is true, the input will use the bidirectional
+// framestream protocol suitable for TCP and unix domain socket connections.
+func NewFrameStreamInput(r io.ReadWriter, bi bool) (input *FrameStreamInput, err error) {
+	return NewFrameStreamInputTimeout(r, bi, 0)
+}
+
+// NewFrameStreamInputTimeout creates a FramestreamInput reading data from the
+// given io.ReadWriter with a timeout applied to reading and (for bidirectional
+// inputs) writing control messages.
+func NewFrameStreamInputTimeout(r io.ReadWriter, bi bool, timeout time.Duration) (input *FrameStreamInput, err error) {
+	reader, err := NewReader(r, &ReaderOptions{
+		Bidirectional: bi,
+		Timeout:       timeout,
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &FrameStreamInput{
+		wait:   make(chan bool),
+		reader: reader,
+		log:    nullLogger{},
+	}, nil
+}
+
+// NewFrameStreamInputFromFilename creates a FrameStreamInput reading from
+// the named file.
+func NewFrameStreamInputFromFilename(fname string) (input *FrameStreamInput, err error) {
+	file, err := os.Open(fname)
+	if err != nil {
+		return nil, err
+	}
+	return NewFrameStreamInput(file, false)
+}
+
+// SetLogger configures a logger for FrameStreamInput read error reporting.
+func (input *FrameStreamInput) SetLogger(logger Logger) {
+	input.log = logger
+}
+
+// ReadInto reads data from the FrameStreamInput into the output channel.
+//
+// ReadInto satisfies the dnstap Input interface.
+func (input *FrameStreamInput) ReadInto(output chan []byte) {
+	buf := make([]byte, MaxPayloadSize)
+	for {
+		n, err := input.reader.ReadFrame(buf)
+		if err == nil {
+			newbuf := make([]byte, n)
+			copy(newbuf, buf)
+			output <- newbuf
+			continue
+		}
+
+		if err != io.EOF {
+			input.log.Printf("FrameStreamInput: Read error: %v", err)
+		}
+
+		break
+	}
+	close(input.wait)
+}
+
+// Wait reeturns when ReadInto has finished.
+//
+// Wait satisfies the dnstap Input interface.
+func (input *FrameStreamInput) Wait() {
+	<-input.wait
+}