inet/flow: add sflow support (#23)

inlet/flow/decoder/sflow/root.go

@@ -0,0 +1,138 @@
+// SPDX-FileCopyrightText: 2022 Tchadel Icard
+// SPDX-License-Identifier: AGPL-3.0-only
+
+// Package sflow handles sFlow v5 decoding.
+package sflow
+
+import (
+	"bytes"
+	"net"
+
+	"github.com/netsampler/goflow2/decoders/sflow"
+	"github.com/netsampler/goflow2/producer"
+
+	"akvorado/common/reporter"
+	"akvorado/inlet/flow/decoder"
+)
+
+// Decoder contains the state for the sFlow v5 decoder.
+type Decoder struct {
+	r *reporter.Reporter
+
+	metrics struct {
+		errors                *reporter.CounterVec
+		stats                 *reporter.CounterVec
+		sampleRecordsStatsSum *reporter.CounterVec
+		sampleStatsSum        *reporter.CounterVec
+	}
+}
+
+// New instantiates a new sFlow decoder.
+func New(r *reporter.Reporter) decoder.Decoder {
+	nd := &Decoder{
+		r: r,
+	}
+
+	nd.metrics.errors = nd.r.CounterVec(
+		reporter.CounterOpts{
+			Name: "errors_count",
+			Help: "sFlows processed errors.",
+		},
+		[]string{"exporter", "error"},
+	)
+	nd.metrics.stats = nd.r.CounterVec(
+		reporter.CounterOpts{
+			Name: "count",
+			Help: "sFlows processed.",
+		},
+		[]string{"exporter", "agent", "version"},
+	)
+	nd.metrics.sampleRecordsStatsSum = nd.r.CounterVec(
+		reporter.CounterOpts{
+			Name: "sample_records_sum",
+			Help: "sFlows samples sum of records.",
+		},
+		[]string{"exporter", "agent", "version", "type"},
+	)
+	nd.metrics.sampleStatsSum = nd.r.CounterVec(
+		reporter.CounterOpts{
+			Name: "sample_sum",
+			Help: "sFlows samples sum.",
+		},
+		[]string{"exporter", "agent", "version", "type"},
+	)
+
+	return nd
+}
+
+// Decode decodes an sFlow payload.
+func (nd *Decoder) Decode(in decoder.RawFlow) []*decoder.FlowMessage {
+	buf := bytes.NewBuffer(in.Payload)
+	key := in.Source.String()
+
+	ts := uint64(in.TimeReceived.UTC().Unix())
+	msgDec, err := sflow.DecodeMessage(buf)
+
+	if err != nil {
+		switch err.(type) {
+		case *sflow.ErrorVersion:
+			nd.metrics.errors.WithLabelValues(key, "error version").Inc()
+		case *sflow.ErrorIPVersion:
+			nd.metrics.errors.WithLabelValues(key, "error ip version").Inc()
+		case *sflow.ErrorDataFormat:
+			nd.metrics.errors.WithLabelValues(key, "error data format").Inc()
+		default:
+			nd.metrics.errors.WithLabelValues(key, "error decoding").Inc()
+		}
+		return nil
+	}
+
+	// Update some stats
+	msgDecConv, ok := msgDec.(sflow.Packet)
+	if !ok {
+		nd.metrics.stats.WithLabelValues(key, "unknown", "unknwon").Inc()
+		return nil
+	}
+	agent := net.IP(msgDecConv.AgentIP).String()
+	version := "5"
+	samples := msgDecConv.Samples
+	nd.metrics.stats.WithLabelValues(key, agent, version).Inc()
+	for _, s := range samples {
+		switch sConv := s.(type) {
+		case sflow.FlowSample:
+			nd.metrics.sampleStatsSum.WithLabelValues(key, agent, version, "FlowSample").
+				Inc()
+			nd.metrics.sampleRecordsStatsSum.WithLabelValues(key, agent, version, "FlowSample").
+				Add(float64(len(sConv.Records)))
+		case sflow.CounterSample:
+			nd.metrics.sampleStatsSum.WithLabelValues(key, agent, version, "CounterSample").
+				Inc()
+			nd.metrics.sampleRecordsStatsSum.WithLabelValues(key, agent, version, "CounterSample").
+				Add(float64(len(sConv.Records)))
+		case sflow.ExpandedFlowSample:
+			nd.metrics.sampleStatsSum.WithLabelValues(key, agent, version, "ExpandedFlowSample").
+				Inc()
+			nd.metrics.sampleRecordsStatsSum.WithLabelValues(key, agent, version, "ExpandedFlowSample").
+				Add(float64(len(sConv.Records)))
+		}
+	}
+
+	flowMessageSet, err := producer.ProcessMessageSFlow(msgDec)
+	for _, fmsg := range flowMessageSet {
+		fmsg.TimeReceived = ts
+		fmsg.TimeFlowStart = ts
+		fmsg.TimeFlowEnd = ts
+	}
+
+	results := make([]*decoder.FlowMessage, len(flowMessageSet))
+	for idx, fmsg := range flowMessageSet {
+		results[idx] = decoder.ConvertGoflowToFlowMessage(fmsg)
+	}
+
+	return results
+}
+
+// Name returns the name of the decoder.
+func (nd *Decoder) Name() string {
+	return "sflow"
+}