Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/sflow/sflow.go

@@ -0,0 +1,139 @@
+//go:generate ../../../tools/readme_config_includer/generator
+package sflow
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"io"
+	"net"
+	"net/url"
+	"strings"
+	"sync"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/config"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+//go:embed sample.conf
+var sampleConfig string
+
+const (
+	maxPacketSize = 64 * 1024
+)
+
+type SFlow struct {
+	ServiceAddress string      `toml:"service_address"`
+	ReadBufferSize config.Size `toml:"read_buffer_size"`
+
+	Log telegraf.Logger `toml:"-"`
+
+	addr    net.Addr
+	decoder *packetDecoder
+	closer  io.Closer
+	wg      sync.WaitGroup
+}
+
+func (*SFlow) SampleConfig() string {
+	return sampleConfig
+}
+
+func (s *SFlow) Init() error {
+	s.decoder = newDecoder()
+	s.decoder.Log = s.Log
+	return nil
+}
+
+// Start starts this sFlow listener listening on the configured network for sFlow packets
+func (s *SFlow) Start(acc telegraf.Accumulator) error {
+	s.decoder.onPacket(func(p *v5Format) {
+		metrics := makeMetrics(p)
+		for _, m := range metrics {
+			acc.AddMetric(m)
+		}
+	})
+
+	u, err := url.Parse(s.ServiceAddress)
+	if err != nil {
+		return err
+	}
+
+	conn, err := listenUDP(u.Scheme, u.Host)
+	if err != nil {
+		return err
+	}
+	s.closer = conn
+	s.addr = conn.LocalAddr()
+
+	if s.ReadBufferSize > 0 {
+		if err := conn.SetReadBuffer(int(s.ReadBufferSize)); err != nil {
+			return err
+		}
+	}
+
+	s.Log.Infof("Listening on %s://%s", s.addr.Network(), s.addr.String())
+
+	s.wg.Add(1)
+	go func() {
+		defer s.wg.Done()
+		s.read(acc, conn)
+	}()
+
+	return nil
+}
+
+// Gather is a NOOP for sFlow as it receives, asynchronously, sFlow network packets
+func (*SFlow) Gather(telegraf.Accumulator) error {
+	return nil
+}
+
+func (s *SFlow) Stop() {
+	if s.closer != nil {
+		s.closer.Close()
+	}
+	s.wg.Wait()
+}
+
+func (s *SFlow) address() net.Addr {
+	return s.addr
+}
+
+func (s *SFlow) read(acc telegraf.Accumulator, conn net.PacketConn) {
+	buf := make([]byte, maxPacketSize)
+	for {
+		n, _, err := conn.ReadFrom(buf)
+		if err != nil {
+			if !strings.HasSuffix(err.Error(), ": use of closed network connection") {
+				acc.AddError(err)
+			}
+			break
+		}
+		s.process(acc, buf[:n])
+	}
+}
+
+func (s *SFlow) process(acc telegraf.Accumulator, buf []byte) {
+	if err := s.decoder.decode(bytes.NewBuffer(buf)); err != nil {
+		acc.AddError(fmt.Errorf("unable to parse incoming packet: %w", err))
+	}
+}
+
+func listenUDP(network, address string) (*net.UDPConn, error) {
+	switch network {
+	case "udp", "udp4", "udp6":
+		addr, err := net.ResolveUDPAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return net.ListenUDP(network, addr)
+	default:
+		return nil, fmt.Errorf("unsupported network type: %s", network)
+	}
+}
+
+func init() {
+	inputs.Add("sflow", func() telegraf.Input {
+		return &SFlow{}
+	})
+}