// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Contains the meters and timers used by the networking layer.
package p2p
import (
"fmt"
"net"
"sync"
"sync/atomic"
"time"
"github.com/dexon-foundation/dexon/p2p/enode"
"github.com/dexon-foundation/dexon/event"
"github.com/dexon-foundation/dexon/log"
"github.com/dexon-foundation/dexon/metrics"
)
const (
MetricsInboundConnects = "p2p/InboundConnects" // Name for the registered inbound connects meter
MetricsInboundTraffic = "p2p/InboundTraffic" // Name for the registered inbound traffic meter
MetricsOutboundConnects = "p2p/OutboundConnects" // Name for the registered outbound connects meter
MetricsOutboundTraffic = "p2p/OutboundTraffic" // Name for the registered outbound traffic meter
MeteredPeerLimit = 1024 // This amount of peers are individually metered
)
var (
ingressConnectMeter = metrics.NewRegisteredMeter(MetricsInboundConnects, nil) // Meter counting the ingress connections
ingressTrafficMeter = metrics.NewRegisteredMeter(MetricsInboundTraffic, nil) // Meter metering the cumulative ingress traffic
egressConnectMeter = metrics.NewRegisteredMeter(MetricsOutboundConnects, nil) // Meter counting the egress connections
egressTrafficMeter = metrics.NewRegisteredMeter(MetricsOutboundTraffic, nil) // Meter metering the cumulative egress traffic
PeerIngressRegistry = metrics.NewPrefixedChildRegistry(metrics.EphemeralRegistry, MetricsInboundTraffic+"/") // Registry containing the peer ingress
PeerEgressRegistry = metrics.NewPrefixedChildRegistry(metrics.EphemeralRegistry, MetricsOutboundTraffic+"/") // Registry containing the peer egress
meteredPeerFeed event.Feed // Event feed for peer metrics
meteredPeerCount int32 // Actually stored peer connection count
)
// MeteredPeerEventType is the type of peer events emitted by a metered connection.
type MeteredPeerEventType int
const (
// PeerConnected is the type of event emitted when a peer successfully
// made the handshake.
PeerConnected MeteredPeerEventType = iota
// PeerDisconnected is the type of event emitted when a peer disconnects.
PeerDisconnected
// PeerHandshakeFailed is the type of event emitted when a peer fails to
// make the handshake or disconnects before the handshake.
PeerHandshakeFailed
)
// MeteredPeerEvent is an event emitted when peers connect or disconnect.
type MeteredPeerEvent struct {
Type MeteredPeerEventType // Type of peer event
IP net.IP // IP address of the peer
ID enode.ID // NodeID of the peer
Elapsed time.Duration // Time elapsed between the connection and the handshake/disconnection
Ingress uint64 // Ingress count at the moment of the event
Egress uint64 // Egress count at the moment of the event
}
// SubscribeMeteredPeerEvent registers a subscription for peer life-cycle events
// if metrics collection is enabled.
func SubscribeMeteredPeerEvent(ch chan<- MeteredPeerEvent) event.Subscription {
return meteredPeerFeed.Subscribe(ch)
}
// meteredConn is a wrapper around a net.Conn that meters both the
// inbound and outbound network traffic.
type meteredConn struct {
net.Conn // Network connection to wrap with metering
connected time.Time // Connection time of the peer
ip net.IP // IP address of the peer
id enode.ID // NodeID of the peer
// trafficMetered denotes if the peer is registered in the traffic registries.
// Its value is true if the metered peer count doesn't reach the limit in the
// moment of the peer's connection.
trafficMetered bool
ingressMeter metrics.Meter // Meter for the read bytes of the peer
egressMeter metrics.Meter // Meter for the written bytes of the peer
lock sync.RWMutex // Lock protecting the metered connection's internals
}
// newMeteredConn creates a new metered connection, bumps the ingress or egress
// connection meter and also increases the metered peer count. If the metrics
// system is disabled or the IP address is unspecified, this function returns
// the original object.
func newMeteredConn(conn net.Conn, ingress bool, ip net.IP) net.Conn {
// Short circuit if metrics are disabled
if !metrics.Enabled {
return conn
}
if ip.IsUnspecified() {
log.Warn("Peer IP is unspecified")
return conn
}
// Bump the connection counters and wrap the connection
if ingress {
ingressConnectMeter.Mark(1)
} else {
egressConnectMeter.Mark(1)
}
return &meteredConn{
Conn: conn,
ip: ip,
connected: time.Now(),
}
}
// Read delegates a network read to the underlying connection, bumping the common
// and the peer ingress traffic meters along the way.
func (c *meteredConn) Read(b []byte) (n int, err error) {
n, err = c.Conn.Read(b)
ingressTrafficMeter.Mark(int64(n))
c.lock.RLock()
if c.trafficMetered {
c.ingressMeter.Mark(int64(n))
}
c.lock.RUnlock()
return n, err
}
// Write delegates a network write to the underlying connection, bumping the common
// and the peer egress traffic meters along the way.
func (c *meteredConn) Write(b []byte) (n int, err error) {
n, err = c.Conn.Write(b)
egressTrafficMeter.Mark(int64(n))
c.lock.RLock()
if c.trafficMetered {
c.egressMeter.Mark(int64(n))
}
c.lock.RUnlock()
return n, err
}
// handshakeDone is called when a peer handshake is done. Registers the peer to
// the ingress and the egress traffic registries using the peer's IP and node ID,
// also emits connect event.
func (c *meteredConn) handshakeDone(id enode.ID) {
if atomic.AddInt32(&meteredPeerCount, 1) >= MeteredPeerLimit {
// Don't register the peer in the traffic registries.
atomic.AddInt32(&meteredPeerCount, -1)
c.lock.Lock()
c.id, c.trafficMetered = id, false
c.lock.Unlock()
log.Warn("Metered peer count reached the limit")
} else {
key := fmt.Sprintf("%s/%s", c.ip, id.String())
c.lock.Lock()
c.id, c.trafficMetered = id, true
c.ingressMeter = metrics.NewRegisteredMeter(key, PeerIngressRegistry)
c.egressMeter = metrics.NewRegisteredMeter(key, PeerEgressRegistry)
c.lock.Unlock()
}
meteredPeerFeed.Send(MeteredPeerEvent{
Type: PeerConnected,
IP: c.ip,
ID: id,
Elapsed: time.Since(c.connected),
})
}
// Close delegates a close operation to the underlying connection, unregisters
// the peer from the traffic registries and emits close event.
func (c *meteredConn) Close() error {
err := c.Conn.Close()
c.lock.RLock()
if c.id == (enode.ID{}) {
// If the peer disconnects before the handshake.
c.lock.RUnlock()
meteredPeerFeed.Send(MeteredPeerEvent{
Type: PeerHandshakeFailed,
IP: c.ip,
Elapsed: time.Since(c.connected),
})
return err
}
id := c.id
if !c.trafficMetered {
// If the peer isn't registered in the traffic registries.
c.lock.RUnlock()
meteredPeerFeed.Send(MeteredPeerEvent{
Type: PeerDisconnected,
IP: c.ip,
ID: id,
})
return err
}
ingress, egress := uint64(c.ingressMeter.Count()), uint64(c.egressMeter.Count())
c.lock.RUnlock()
// Decrement the metered peer count
atomic.AddInt32(&meteredPeerCount, -1)
// Unregister the peer from the traffic registries
key := fmt.Sprintf("%s/%s", c.ip, id)
PeerIngressRegistry.Unregister(key)
PeerEgressRegistry.Unregister(key)
meteredPeerFeed.Send(MeteredPeerEvent{
Type: PeerDisconnected,
IP: c.ip,
ID: id,
Ingress: ingress,
Egress: egress,
})
return err
}
