add meta packet statistics (#230)

This change add more metrics around "meta" (non "message" type packets).
For lighthouse packets, we also record statistics around the specific
lighthouse meta type.

We don't keep statistics for the "message" type so that we don't slow
down the fast path (and you can just look at metrics on the tun
interface to find that information).

message_metrics.go

@@ -0,0 +1,97 @@
+package nebula
+
+import (
+	"fmt"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+type MessageMetrics struct {
+	rx [][]metrics.Counter
+	tx [][]metrics.Counter
+
+	rxUnknown metrics.Counter
+	txUnknown metrics.Counter
+}
+
+func (m *MessageMetrics) Rx(t NebulaMessageType, s NebulaMessageSubType, i int64) {
+	if m != nil {
+		if t >= 0 && int(t) < len(m.rx) && s >= 0 && int(s) < len(m.rx[t]) {
+			m.rx[t][s].Inc(i)
+		} else if m.rxUnknown != nil {
+			m.rxUnknown.Inc(i)
+		}
+	}
+}
+func (m *MessageMetrics) Tx(t NebulaMessageType, s NebulaMessageSubType, i int64) {
+	if m != nil {
+		if t >= 0 && int(t) < len(m.tx) && s >= 0 && int(s) < len(m.tx[t]) {
+			m.tx[t][s].Inc(i)
+		} else if m.txUnknown != nil {
+			m.txUnknown.Inc(i)
+		}
+	}
+}
+
+func newMessageMetrics() *MessageMetrics {
+	gen := func(t string) [][]metrics.Counter {
+		return [][]metrics.Counter{
+			{
+				metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.handshake_ixpsk0", t), nil),
+			},
+			nil,
+			{metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.recv_error", t), nil)},
+			{metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.lighthouse", t), nil)},
+			{
+				metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.test_request", t), nil),
+				metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.test_response", t), nil),
+			},
+			{metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.close_tunnel", t), nil)},
+		}
+	}
+	return &MessageMetrics{
+		rx: gen("rx"),
+		tx: gen("tx"),
+
+		rxUnknown: metrics.GetOrRegisterCounter("messages.rx.other", nil),
+		txUnknown: metrics.GetOrRegisterCounter("messages.tx.other", nil),
+	}
+}
+
+// Historically we only recorded recv_error, so this is backwards compat
+func newMessageMetricsOnlyRecvError() *MessageMetrics {
+	gen := func(t string) [][]metrics.Counter {
+		return [][]metrics.Counter{
+			nil,
+			nil,
+			{metrics.GetOrRegisterCounter(fmt.Sprintf("messages.%s.recv_error", t), nil)},
+		}
+	}
+	return &MessageMetrics{
+		rx: gen("rx"),
+		tx: gen("tx"),
+	}
+}
+
+func newLighthouseMetrics() *MessageMetrics {
+	gen := func(t string) [][]metrics.Counter {
+		h := make([][]metrics.Counter, len(NebulaMeta_MessageType_name))
+		used := []NebulaMeta_MessageType{
+			NebulaMeta_HostQuery,
+			NebulaMeta_HostQueryReply,
+			NebulaMeta_HostUpdateNotification,
+			NebulaMeta_HostPunchNotification,
+		}
+		for _, i := range used {
+			h[i] = []metrics.Counter{metrics.GetOrRegisterCounter(fmt.Sprintf("lighthouse.%s.%s", t, i.String()), nil)}
+		}
+		return h
+	}
+	return &MessageMetrics{
+		rx: gen("rx"),
+		tx: gen("tx"),
+
+		rxUnknown: metrics.GetOrRegisterCounter("lighthouse.rx.other", nil),
+		txUnknown: metrics.GetOrRegisterCounter("lighthouse.tx.other", nil),
+	}
+}