Dnstap plugin refactoring (#1257)

This commit is contained in:
Uladzimir Trehubenka
2017-11-28 00:36:14 +03:00
committed by Miek Gieben
parent 06006fac56
commit 6d6e1357b9
7 changed files with 223 additions and 416 deletions

View File

@@ -2,67 +2,100 @@ package dnstapio
import (
"log"
"net"
"time"
tap "github.com/dnstap/golang-dnstap"
fs "github.com/farsightsec/golang-framestream"
"github.com/golang/protobuf/proto"
)
// DnstapIO wraps the dnstap I/O routine.
type DnstapIO struct {
protocol Protocol
queue chan tap.Dnstap
stop chan bool
const (
tcpTimeout = 4 * time.Second
flushTimeout = 1 * time.Second
queueSize = 1000
)
type dnstapIO struct {
enc *fs.Encoder
conn net.Conn
queue chan tap.Dnstap
}
// Protocol is either `out.TCP` or `out.Socket`.
type Protocol interface {
// Write takes a single frame at once.
Write([]byte) (int, error)
Close() error
// New returns a new and initialized DnstapIO.
func New() DnstapIO {
return &dnstapIO{queue: make(chan tap.Dnstap, queueSize)}
}
// New dnstap I/O routine from Protocol.
func New(w Protocol) *DnstapIO {
dio := DnstapIO{}
dio.protocol = w
dio.queue = make(chan tap.Dnstap, 10)
dio.stop = make(chan bool)
// DnstapIO interface
type DnstapIO interface {
Connect(endpoint string, socket bool) error
Dnstap(payload tap.Dnstap)
Close()
}
// Connect connects to the dnstop endpoint.
func (dio *dnstapIO) Connect(endpoint string, socket bool) error {
var err error
if socket {
dio.conn, err = net.Dial("unix", endpoint)
} else {
dio.conn, err = net.DialTimeout("tcp", endpoint, tcpTimeout)
}
if err != nil {
return err
}
dio.enc, err = fs.NewEncoder(dio.conn, &fs.EncoderOptions{
ContentType: []byte("protobuf:dnstap.Dnstap"),
Bidirectional: true,
})
if err != nil {
return err
}
go dio.serve()
return &dio
return nil
}
// Dnstap enqueues the payload for log.
func (dio *DnstapIO) Dnstap(payload tap.Dnstap) {
func (dio *dnstapIO) Dnstap(payload tap.Dnstap) {
select {
case dio.queue <- payload:
default:
log.Println("[WARN] Dnstap payload dropped.")
}
}
func (dio *DnstapIO) serve() {
for {
select {
case payload := <-dio.queue:
frame, err := proto.Marshal(&payload)
if err == nil {
dio.protocol.Write(frame)
} else {
log.Printf("[ERROR] Invalid dnstap payload dropped: %s\n", err)
}
case <-dio.stop:
close(dio.queue)
dio.stop <- true
return
}
log.Printf("[ERROR] Dnstap payload dropped")
}
}
// Close waits until the I/O routine is finished to return.
func (dio DnstapIO) Close() error {
dio.stop <- true
<-dio.stop
close(dio.stop)
return dio.protocol.Close()
func (dio *dnstapIO) Close() {
close(dio.queue)
}
func (dio *dnstapIO) serve() {
timeout := time.After(flushTimeout)
for {
select {
case payload, ok := <-dio.queue:
if !ok {
dio.enc.Close()
dio.conn.Close()
return
}
frame, err := proto.Marshal(&payload)
if err != nil {
log.Printf("[ERROR] Invalid dnstap payload dropped: %s", err)
continue
}
_, err = dio.enc.Write(frame)
if err != nil {
log.Printf("[ERROR] Cannot write dnstap payload: %s", err)
continue
}
case <-timeout:
err := dio.enc.Flush()
if err != nil {
log.Printf("[ERROR] Cannot flush dnstap payloads: %s", err)
}
timeout = time.After(flushTimeout)
}
}
}

View File

@@ -1,78 +1,155 @@
package dnstapio
import (
"bytes"
"io/ioutil"
"log"
"net"
"sync"
"testing"
"time"
tap "github.com/dnstap/golang-dnstap"
fs "github.com/farsightsec/golang-framestream"
)
func init() {
log.SetOutput(ioutil.Discard)
func accept(t *testing.T, l net.Listener, count int) {
server, err := l.Accept()
if err != nil {
t.Fatalf("server accept: %s", err)
return
}
dec, err := fs.NewDecoder(server, &fs.DecoderOptions{
ContentType: []byte("protobuf:dnstap.Dnstap"),
Bidirectional: true,
})
if err != nil {
t.Fatalf("server decoder: %s", err)
return
}
for i := 0; i < count; i++ {
if _, err := dec.Decode(); err != nil {
t.Errorf("server decode: %s", err)
}
}
if err := server.Close(); err != nil {
t.Error(err)
}
}
type buf struct {
*bytes.Buffer
cost time.Duration
const endpointTCP = "localhost:0"
func TestTCP(t *testing.T) {
dio := New()
err := dio.Connect(endpointTCP, false)
if err == nil {
t.Fatal("Not listening but no error")
}
// Start TCP listener
l, err := net.Listen("tcp", endpointTCP)
if err != nil {
t.Fatalf("Cannot start listener: %s", err)
}
defer l.Close()
var wg sync.WaitGroup
wg.Add(1)
go func() {
accept(t, l, 1)
wg.Done()
}()
err = dio.Connect(l.Addr().String(), false)
if err != nil {
t.Fatalf("Cannot connect to listener: %s", err)
}
msg := tap.Dnstap_MESSAGE
dio.Dnstap(tap.Dnstap{Type: &msg})
wg.Wait()
dio.Close()
}
func (b buf) Write(frame []byte) (int, error) {
time.Sleep(b.cost)
return b.Buffer.Write(frame)
}
const endpointSocket = "dnstap.sock"
func (b buf) Close() error {
return nil
func TestSocket(t *testing.T) {
dio := New()
err := dio.Connect(endpointSocket, true)
if err == nil {
t.Fatal("Not listening but no error")
}
// Start Socket listener
l, err := net.Listen("unix", endpointSocket)
if err != nil {
t.Fatalf("Cannot start listener: %s", err)
}
defer l.Close()
var wg sync.WaitGroup
wg.Add(1)
go func() {
accept(t, l, 1)
wg.Done()
}()
err = dio.Connect(endpointSocket, true)
if err != nil {
t.Fatalf("Cannot connect to listener: %s", err)
}
msg := tap.Dnstap_MESSAGE
dio.Dnstap(tap.Dnstap{Type: &msg})
wg.Wait()
dio.Close()
}
func TestRace(t *testing.T) {
b := buf{&bytes.Buffer{}, 100 * time.Millisecond}
dio := New(b)
wg := &sync.WaitGroup{}
wg.Add(10)
for i := 0; i < 10; i++ {
timeout := time.After(time.Second)
go func() {
for {
select {
case <-timeout:
wg.Done()
return
default:
time.Sleep(50 * time.Millisecond)
t := tap.Dnstap_MESSAGE
dio.Dnstap(tap.Dnstap{Type: &t})
}
}
}()
}
wg.Wait()
}
count := 10
dio := New()
func TestClose(t *testing.T) {
done := make(chan bool)
var dio *DnstapIO
go func() {
b := buf{&bytes.Buffer{}, 0}
dio = New(b)
dio.Close()
close(done)
}()
select {
case <-done:
case <-time.After(time.Second):
t.Fatal("Not closing.")
err := dio.Connect(endpointTCP, false)
if err == nil {
t.Fatal("Not listening but no error")
}
func() {
defer func() {
if err := recover(); err == nil {
t.Fatal("Send on closed channel.")
}
}()
dio.Dnstap(tap.Dnstap{})
// Start TCP listener
l, err := net.Listen("tcp", endpointTCP)
if err != nil {
t.Fatalf("Cannot start listener: %s", err)
}
defer l.Close()
var wg sync.WaitGroup
wg.Add(1)
go func() {
accept(t, l, count)
wg.Done()
}()
err = dio.Connect(l.Addr().String(), false)
if err != nil {
t.Fatalf("Cannot connect to listener: %s", err)
}
msg := tap.Dnstap_MESSAGE
wg.Add(count)
for i := 0; i < count; i++ {
go func(i byte) {
time.Sleep(50 * time.Millisecond)
dio.Dnstap(tap.Dnstap{Type: &msg, Extra: []byte{i}})
wg.Done()
}(byte(i))
}
wg.Wait()
dio.Close()
}