/
netflow.go
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/
netflow.go
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//go:generate ../../../tools/readme_config_includer/generator
package netflow
import (
_ "embed"
"encoding/hex"
"errors"
"fmt"
"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
type protocolDecoder interface {
Init() error
Decode(net.IP, []byte) ([]telegraf.Metric, error)
}
type NetFlow struct {
ServiceAddress string `toml:"service_address"`
ReadBufferSize config.Size `toml:"read_buffer_size"`
Protocol string `toml:"protocol"`
DumpPackets bool `toml:"dump_packets"`
Log telegraf.Logger `toml:"-"`
conn *net.UDPConn
decoder protocolDecoder
wg sync.WaitGroup
}
func (*NetFlow) SampleConfig() string {
return sampleConfig
}
func (n *NetFlow) Init() error {
if n.ServiceAddress == "" {
return errors.New("service_address required")
}
u, err := url.Parse(n.ServiceAddress)
if err != nil {
return fmt.Errorf("invalid service address %q: %w", n.ServiceAddress, err)
}
switch u.Scheme {
case "udp", "udp4", "udp6":
default:
return fmt.Errorf("invalid scheme %q, should be 'udp', 'udp4' or 'udp6'", u.Scheme)
}
switch strings.ToLower(n.Protocol) {
case "", "netflow v9", "ipfix":
n.decoder = &netflowDecoder{Log: n.Log}
case "netflow v5":
n.decoder = &netflowv5Decoder{}
default:
return fmt.Errorf("invalid protocol %q, only supports 'netflow v5', 'netflow v9' and 'ipfix'", n.Protocol)
}
return n.decoder.Init()
}
func (n *NetFlow) Start(acc telegraf.Accumulator) error {
u, err := url.Parse(n.ServiceAddress)
if err != nil {
return err
}
addr, err := net.ResolveUDPAddr(u.Scheme, u.Host)
if err != nil {
return err
}
conn, err := net.ListenUDP(u.Scheme, addr)
if err != nil {
return err
}
n.conn = conn
if n.ReadBufferSize > 0 {
if err := conn.SetReadBuffer(int(n.ReadBufferSize)); err != nil {
return err
}
}
n.Log.Infof("Listening on %s://%s", n.conn.LocalAddr().Network(), n.conn.LocalAddr().String())
n.wg.Add(1)
go func() {
defer n.wg.Done()
n.read(acc)
}()
return nil
}
func (n *NetFlow) Stop() {
if n.conn != nil {
_ = n.conn.Close()
}
n.wg.Wait()
}
func (n *NetFlow) read(acc telegraf.Accumulator) {
buf := make([]byte, 64*1024) // 64kB
for {
count, src, err := n.conn.ReadFromUDP(buf)
if err != nil {
if !strings.HasSuffix(err.Error(), ": use of closed network connection") {
acc.AddError(err)
}
break
}
n.Log.Debugf("received %d bytes\n", count)
if count < 1 {
continue
}
if n.DumpPackets {
n.Log.Debugf("raw data: %s", hex.EncodeToString(buf[:count]))
}
metrics, err := n.decoder.Decode(src.IP, buf[:count])
if err != nil {
acc.AddError(err)
continue
}
for _, m := range metrics {
acc.AddMetric(m)
}
}
}
func (n *NetFlow) Gather(_ telegraf.Accumulator) error {
return nil
}
// Register the plugin
func init() {
inputs.Add("netflow", func() telegraf.Input {
return &NetFlow{}
})
}