status-go/waku/peer.go

321 lines
8.8 KiB
Go

// Copyright 2019 The Waku Library Authors.
//
// The Waku 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 Waku library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty off
// 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 Waku library. If not, see <http://www.gnu.org/licenses/>.
//
// This software uses the go-ethereum library, which is licensed
// under the GNU Lesser General Public Library, version 3 or any later.
package waku
import (
"bytes"
"fmt"
"math"
"sync"
"time"
mapset "github.com/deckarep/golang-set"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rlp"
"go.uber.org/zap"
)
// Peer represents a waku protocol peer connection.
type Peer struct {
host *Waku
peer *p2p.Peer
ws p2p.MsgReadWriter
logger *zap.Logger
trusted bool
powRequirement float64
bloomMu sync.Mutex
bloomFilter []byte
fullNode bool
confirmationsEnabled bool
rateLimitsMu sync.Mutex
rateLimits RateLimits
known mapset.Set // Messages already known by the peer to avoid wasting bandwidth
quit chan struct{}
}
// newPeer creates a new waku peer object, but does not run the handshake itself.
func newPeer(host *Waku, remote *p2p.Peer, rw p2p.MsgReadWriter, logger *zap.Logger) *Peer {
if logger == nil {
logger = zap.NewNop()
}
return &Peer{
host: host,
peer: remote,
ws: rw,
logger: logger,
trusted: false,
powRequirement: 0.0,
known: mapset.NewSet(),
quit: make(chan struct{}),
bloomFilter: MakeFullNodeBloom(),
fullNode: true,
}
}
// start initiates the peer updater, periodically broadcasting the waku packets
// into the network.
func (p *Peer) start() {
go p.update()
p.logger.Debug("starting peer", zap.Binary("peerID", p.ID()))
}
// stop terminates the peer updater, stopping message forwarding to it.
func (p *Peer) stop() {
close(p.quit)
p.logger.Debug("stopping peer", zap.Binary("peerID", p.ID()))
}
// handshake sends the protocol initiation status message to the remote peer and
// verifies the remote status too.
func (p *Peer) handshake() error {
// Send the handshake status message asynchronously
errc := make(chan error, 1)
isLightNode := p.host.LightClientMode()
isRestrictedLightNodeConnection := p.host.LightClientModeConnectionRestricted()
go func() {
pow := p.host.MinPow()
powConverted := math.Float64bits(pow)
bloom := p.host.BloomFilter()
confirmationsEnabled := p.host.ConfirmationsEnabled()
rateLimits := p.host.RateLimits()
errc <- p2p.SendItems(p.ws, statusCode, ProtocolVersion, powConverted, bloom, isLightNode, confirmationsEnabled, rateLimits)
}()
// Fetch the remote status packet and verify protocol match
packet, err := p.ws.ReadMsg()
if err != nil {
return err
}
if packet.Code != statusCode {
return fmt.Errorf("p [%x] sent packet %x before status packet", p.ID(), packet.Code)
}
s := rlp.NewStream(packet.Payload, uint64(packet.Size))
_, err = s.List()
if err != nil {
return fmt.Errorf("p [%x] sent bad status message: %v", p.ID(), err)
}
peerVersion, err := s.Uint()
if err != nil {
return fmt.Errorf("p [%x] sent bad status message (unable to decode version): %v", p.ID(), err)
}
if peerVersion != ProtocolVersion {
return fmt.Errorf("p [%x]: protocol version mismatch %d != %d", p.ID(), peerVersion, ProtocolVersion)
}
// only version is mandatory, subsequent parameters are optional
powRaw, err := s.Uint()
if err == nil {
pow := math.Float64frombits(powRaw)
if math.IsInf(pow, 0) || math.IsNaN(pow) || pow < 0.0 {
return fmt.Errorf("p [%x] sent bad status message: invalid pow", p.ID())
}
p.powRequirement = pow
var bloom []byte
err = s.Decode(&bloom)
if err == nil {
sz := len(bloom)
if sz != BloomFilterSize && sz != 0 {
return fmt.Errorf("p [%x] sent bad status message: wrong bloom filter size %d", p.ID(), sz)
}
p.setBloomFilter(bloom)
}
}
isRemotePeerLightNode, _ := s.Bool()
if isRemotePeerLightNode && isLightNode && isRestrictedLightNodeConnection {
return fmt.Errorf("p [%x] is useless: two light client communication restricted", p.ID())
}
confirmationsEnabled, err := s.Bool()
if err != nil || !confirmationsEnabled {
p.logger.Info("confirmations are disabled for peer", zap.Binary("peer", p.ID()))
} else {
p.confirmationsEnabled = confirmationsEnabled
}
var rateLimits RateLimits
if err := s.Decode(&rateLimits); err != nil {
p.logger.Info("rate limiting is disabled for peer", zap.Binary("peer", p.ID()))
} else {
p.setRateLimits(rateLimits)
}
if err := <-errc; err != nil {
return fmt.Errorf("p [%x] failed to send status packet: %v", p.ID(), err)
}
return nil
}
// update executes periodic operations on the peer, including message transmission
// and expiration.
func (p *Peer) update() {
// Start the tickers for the updates
expire := time.NewTicker(expirationCycle)
transmit := time.NewTicker(transmissionCycle)
// Loop and transmit until termination is requested
for {
select {
case <-expire.C:
p.expire()
case <-transmit.C:
if err := p.broadcast(); err != nil {
p.logger.Debug("broadcasting failed", zap.Binary("peer", p.ID()), zap.Error(err))
return
}
case <-p.quit:
return
}
}
}
// mark marks an envelope known to the peer so that it won't be sent back.
func (p *Peer) mark(envelope *Envelope) {
p.known.Add(envelope.Hash())
}
// marked checks if an envelope is already known to the remote peer.
func (p *Peer) marked(envelope *Envelope) bool {
return p.known.Contains(envelope.Hash())
}
// expire iterates over all the known envelopes in the host and removes all
// expired (unknown) ones from the known list.
func (p *Peer) expire() {
unmark := make(map[common.Hash]struct{})
p.known.Each(func(v interface{}) bool {
if !p.host.isEnvelopeCached(v.(common.Hash)) {
unmark[v.(common.Hash)] = struct{}{}
}
return true
})
// Dump all known but no longer cached
for hash := range unmark {
p.known.Remove(hash)
}
}
// broadcast iterates over the collection of envelopes and transmits yet unknown
// ones over the network.
func (p *Peer) broadcast() error {
envelopes := p.host.Envelopes()
bundle := make([]*Envelope, 0, len(envelopes))
for _, envelope := range envelopes {
if !p.marked(envelope) && envelope.PoW() >= p.powRequirement && p.bloomMatch(envelope) {
bundle = append(bundle, envelope)
}
}
if len(bundle) == 0 {
return nil
}
batchHash, err := sendBundle(p.ws, bundle)
if err != nil {
p.logger.Debug("failed to deliver envelopes", zap.Binary("peer", p.ID()), zap.Error(err))
return err
}
// mark envelopes only if they were successfully sent
for _, e := range bundle {
p.mark(e)
event := EnvelopeEvent{
Event: EventEnvelopeSent,
Hash: e.Hash(),
Peer: p.peer.ID(),
}
if p.confirmationsEnabled {
event.Batch = batchHash
}
p.host.envelopeFeed.Send(event)
}
p.logger.Debug("broadcasted bundles successfully", zap.Binary("peer", p.ID()), zap.Int("count", len(bundle)))
return nil
}
// ID returns a peer's id
func (p *Peer) ID() []byte {
id := p.peer.ID()
return id[:]
}
func (p *Peer) notifyAboutPowRequirementChange(pow float64) error {
i := math.Float64bits(pow)
return p2p.Send(p.ws, powRequirementCode, i)
}
func (p *Peer) notifyAboutBloomFilterChange(bloom []byte) error {
return p2p.Send(p.ws, bloomFilterExCode, bloom)
}
func (p *Peer) bloomMatch(env *Envelope) bool {
p.bloomMu.Lock()
defer p.bloomMu.Unlock()
return p.fullNode || BloomFilterMatch(p.bloomFilter, env.Bloom())
}
func (p *Peer) setBloomFilter(bloom []byte) {
p.bloomMu.Lock()
defer p.bloomMu.Unlock()
p.bloomFilter = bloom
p.fullNode = isFullNode(bloom)
if p.fullNode && p.bloomFilter == nil {
p.bloomFilter = MakeFullNodeBloom()
}
}
func (p *Peer) setRateLimits(r RateLimits) {
p.rateLimitsMu.Lock()
p.rateLimits = r
p.rateLimitsMu.Unlock()
}
func MakeFullNodeBloom() []byte {
bloom := make([]byte, BloomFilterSize)
for i := 0; i < BloomFilterSize; i++ {
bloom[i] = 0xFF
}
return bloom
}
func sendBundle(rw p2p.MsgWriter, bundle []*Envelope) (rst common.Hash, err error) {
data, err := rlp.EncodeToBytes(bundle)
if err != nil {
return
}
err = rw.WriteMsg(p2p.Msg{
Code: messagesCode,
Size: uint32(len(data)),
Payload: bytes.NewBuffer(data),
})
if err != nil {
return
}
return crypto.Keccak256Hash(data), nil
}