Official Go implementation of the Ethereum protocol
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go-ethereum/swarm/network/stream/messages.go

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// Copyright 2018 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/>.
package stream
import (
"context"
"fmt"
"time"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/swarm/log"
bv "github.com/ethereum/go-ethereum/swarm/network/bitvector"
"github.com/ethereum/go-ethereum/swarm/spancontext"
"github.com/ethereum/go-ethereum/swarm/storage"
"github.com/opentracing/opentracing-go"
)
var syncBatchTimeout = 30 * time.Second
// Stream defines a unique stream identifier.
type Stream struct {
// Name is used for Client and Server functions identification.
Name string
// Key is the name of specific stream data.
Key string
// Live defines whether the stream delivers only new data
// for the specific stream.
Live bool
}
func NewStream(name string, key string, live bool) Stream {
return Stream{
Name: name,
Key: key,
Live: live,
}
}
// String return a stream id based on all Stream fields.
func (s Stream) String() string {
t := "h"
if s.Live {
t = "l"
}
return fmt.Sprintf("%s|%s|%s", s.Name, s.Key, t)
}
// SubcribeMsg is the protocol msg for requesting a stream(section)
type SubscribeMsg struct {
Stream Stream
History *Range `rlp:"nil"`
Priority uint8 // delivered on priority channel
}
// RequestSubscriptionMsg is the protocol msg for a node to request subscription to a
// specific stream
type RequestSubscriptionMsg struct {
Stream Stream
History *Range `rlp:"nil"`
Priority uint8 // delivered on priority channel
}
func (p *Peer) handleRequestSubscription(ctx context.Context, req *RequestSubscriptionMsg) (err error) {
log.Debug(fmt.Sprintf("handleRequestSubscription: streamer %s to subscribe to %s with stream %s", p.streamer.addr, p.ID(), req.Stream))
if err = p.streamer.Subscribe(p.ID(), req.Stream, req.History, req.Priority); err != nil {
// The error will be sent as a subscribe error message
// and will not be returned as it will prevent any new message
// exchange between peers over p2p. Instead, error will be returned
// only if there is one from sending subscribe error message.
err = p.Send(ctx, SubscribeErrorMsg{
Error: err.Error(),
})
}
return err
}
func (p *Peer) handleSubscribeMsg(ctx context.Context, req *SubscribeMsg) (err error) {
metrics.GetOrRegisterCounter("peer.handlesubscribemsg", nil).Inc(1)
defer func() {
if err != nil {
// The error will be sent as a subscribe error message
// and will not be returned as it will prevent any new message
// exchange between peers over p2p. Instead, error will be returned
// only if there is one from sending subscribe error message.
err = p.Send(context.TODO(), SubscribeErrorMsg{
Error: err.Error(),
})
}
}()
log.Debug("received subscription", "from", p.streamer.addr, "peer", p.ID(), "stream", req.Stream, "history", req.History)
f, err := p.streamer.GetServerFunc(req.Stream.Name)
if err != nil {
return err
}
s, err := f(p, req.Stream.Key, req.Stream.Live)
if err != nil {
return err
}
os, err := p.setServer(req.Stream, s, req.Priority)
if err != nil {
return err
}
var from uint64
var to uint64
if !req.Stream.Live && req.History != nil {
from = req.History.From
to = req.History.To
}
go func() {
if err := p.SendOfferedHashes(os, from, to); err != nil {
log.Warn("SendOfferedHashes error", "peer", p.ID().TerminalString(), "err", err)
}
}()
if req.Stream.Live && req.History != nil {
// subscribe to the history stream
s, err := f(p, req.Stream.Key, false)
if err != nil {
return err
}
os, err := p.setServer(getHistoryStream(req.Stream), s, getHistoryPriority(req.Priority))
if err != nil {
return err
}
go func() {
if err := p.SendOfferedHashes(os, req.History.From, req.History.To); err != nil {
log.Warn("SendOfferedHashes error", "peer", p.ID().TerminalString(), "err", err)
}
}()
}
return nil
}
type SubscribeErrorMsg struct {
Error string
}
func (p *Peer) handleSubscribeErrorMsg(req *SubscribeErrorMsg) (err error) {
return fmt.Errorf("subscribe to peer %s: %v", p.ID(), req.Error)
}
type UnsubscribeMsg struct {
Stream Stream
}
func (p *Peer) handleUnsubscribeMsg(req *UnsubscribeMsg) error {
return p.removeServer(req.Stream)
}
type QuitMsg struct {
Stream Stream
}
func (p *Peer) handleQuitMsg(req *QuitMsg) error {
return p.removeClient(req.Stream)
}
// OfferedHashesMsg is the protocol msg for offering to hand over a
// stream section
type OfferedHashesMsg struct {
Stream Stream // name of Stream
From, To uint64 // peer and db-specific entry count
Hashes []byte // stream of hashes (128)
*HandoverProof // HandoverProof
}
// String pretty prints OfferedHashesMsg
func (m OfferedHashesMsg) String() string {
return fmt.Sprintf("Stream '%v' [%v-%v] (%v)", m.Stream, m.From, m.To, len(m.Hashes)/HashSize)
}
// handleOfferedHashesMsg protocol msg handler calls the incoming streamer interface
// Filter method
func (p *Peer) handleOfferedHashesMsg(ctx context.Context, req *OfferedHashesMsg) error {
metrics.GetOrRegisterCounter("peer.handleofferedhashes", nil).Inc(1)
var sp opentracing.Span
ctx, sp = spancontext.StartSpan(
ctx,
"handle.offered.hashes")
defer sp.Finish()
c, _, err := p.getOrSetClient(req.Stream, req.From, req.To)
if err != nil {
return err
}
hashes := req.Hashes
lenHashes := len(hashes)
if lenHashes%HashSize != 0 {
return fmt.Errorf("error invalid hashes length (len: %v)", lenHashes)
}
want, err := bv.New(lenHashes / HashSize)
if err != nil {
return fmt.Errorf("error initiaising bitvector of length %v: %v", lenHashes/HashSize, err)
}
ctr := 0
errC := make(chan error)
ctx, cancel := context.WithTimeout(ctx, syncBatchTimeout)
ctx = context.WithValue(ctx, "source", p.ID().String())
for i := 0; i < lenHashes; i += HashSize {
hash := hashes[i : i+HashSize]
if wait := c.NeedData(ctx, hash); wait != nil {
ctr++
want.Set(i/HashSize, true)
// create request and wait until the chunk data arrives and is stored
go func(w func(context.Context) error) {
select {
case errC <- w(ctx):
case <-ctx.Done():
}
}(wait)
}
}
go func() {
defer cancel()
for i := 0; i < ctr; i++ {
select {
case err := <-errC:
if err != nil {
log.Debug("client.handleOfferedHashesMsg() error waiting for chunk, dropping peer", "peer", p.ID(), "err", err)
p.Drop(err)
return
}
case <-ctx.Done():
log.Debug("client.handleOfferedHashesMsg() context done", "ctx.Err()", ctx.Err())
return
case <-c.quit:
log.Debug("client.handleOfferedHashesMsg() quit")
return
}
}
select {
case c.next <- c.batchDone(p, req, hashes):
case <-c.quit:
log.Debug("client.handleOfferedHashesMsg() quit")
case <-ctx.Done():
log.Debug("client.handleOfferedHashesMsg() context done", "ctx.Err()", ctx.Err())
}
}()
// only send wantedKeysMsg if all missing chunks of the previous batch arrived
// except
if c.stream.Live {
c.sessionAt = req.From
}
from, to := c.nextBatch(req.To + 1)
log.Trace("set next batch", "peer", p.ID(), "stream", req.Stream, "from", req.From, "to", req.To, "addr", p.streamer.addr)
if from == to {
return nil
}
msg := &WantedHashesMsg{
Stream: req.Stream,
Want: want.Bytes(),
From: from,
To: to,
}
go func() {
log.Trace("sending want batch", "peer", p.ID(), "stream", msg.Stream, "from", msg.From, "to", msg.To)
select {
case err := <-c.next:
if err != nil {
log.Warn("c.next error dropping peer", "err", err)
p.Drop(err)
return
}
case <-c.quit:
log.Debug("client.handleOfferedHashesMsg() quit")
return
case <-ctx.Done():
log.Debug("client.handleOfferedHashesMsg() context done", "ctx.Err()", ctx.Err())
return
}
log.Trace("sending want batch", "peer", p.ID(), "stream", msg.Stream, "from", msg.From, "to", msg.To)
err := p.SendPriority(ctx, msg, c.priority)
if err != nil {
log.Warn("SendPriority error", "err", err)
}
}()
return nil
}
// WantedHashesMsg is the protocol msg data for signaling which hashes
// offered in OfferedHashesMsg downstream peer actually wants sent over
type WantedHashesMsg struct {
Stream Stream
Want []byte // bitvector indicating which keys of the batch needed
From, To uint64 // next interval offset - empty if not to be continued
}
// String pretty prints WantedHashesMsg
func (m WantedHashesMsg) String() string {
return fmt.Sprintf("Stream '%v', Want: %x, Next: [%v-%v]", m.Stream, m.Want, m.From, m.To)
}
// handleWantedHashesMsg protocol msg handler
// * sends the next batch of unsynced keys
// * sends the actual data chunks as per WantedHashesMsg
func (p *Peer) handleWantedHashesMsg(ctx context.Context, req *WantedHashesMsg) error {
metrics.GetOrRegisterCounter("peer.handlewantedhashesmsg", nil).Inc(1)
log.Trace("received wanted batch", "peer", p.ID(), "stream", req.Stream, "from", req.From, "to", req.To)
s, err := p.getServer(req.Stream)
if err != nil {
return err
}
hashes := s.currentBatch
// launch in go routine since GetBatch blocks until new hashes arrive
go func() {
if err := p.SendOfferedHashes(s, req.From, req.To); err != nil {
log.Warn("SendOfferedHashes error", "err", err)
}
}()
// go p.SendOfferedHashes(s, req.From, req.To)
l := len(hashes) / HashSize
log.Trace("wanted batch length", "peer", p.ID(), "stream", req.Stream, "from", req.From, "to", req.To, "lenhashes", len(hashes), "l", l)
want, err := bv.NewFromBytes(req.Want, l)
if err != nil {
return fmt.Errorf("error initiaising bitvector of length %v: %v", l, err)
}
for i := 0; i < l; i++ {
if want.Get(i) {
metrics.GetOrRegisterCounter("peer.handlewantedhashesmsg.actualget", nil).Inc(1)
hash := hashes[i*HashSize : (i+1)*HashSize]
data, err := s.GetData(ctx, hash)
if err != nil {
return fmt.Errorf("handleWantedHashesMsg get data %x: %v", hash, err)
}
chunk := storage.NewChunk(hash, data)
if err := p.Deliver(ctx, chunk, s.priority); err != nil {
return err
}
}
}
return nil
}
// Handover represents a statement that the upstream peer hands over the stream section
type Handover struct {
Stream Stream // name of stream
Start, End uint64 // index of hashes
Root []byte // Root hash for indexed segment inclusion proofs
}
// HandoverProof represents a signed statement that the upstream peer handed over the stream section
type HandoverProof struct {
Sig []byte // Sign(Hash(Serialisation(Handover)))
*Handover
}
// Takeover represents a statement that downstream peer took over (stored all data)
// handed over
type Takeover Handover
// TakeoverProof represents a signed statement that the downstream peer took over
// the stream section
type TakeoverProof struct {
Sig []byte // Sign(Hash(Serialisation(Takeover)))
*Takeover
}
// TakeoverProofMsg is the protocol msg sent by downstream peer
type TakeoverProofMsg TakeoverProof
// String pretty prints TakeoverProofMsg
func (m TakeoverProofMsg) String() string {
return fmt.Sprintf("Stream: '%v' [%v-%v], Root: %x, Sig: %x", m.Stream, m.Start, m.End, m.Root, m.Sig)
}
func (p *Peer) handleTakeoverProofMsg(ctx context.Context, req *TakeoverProofMsg) error {
_, err := p.getServer(req.Stream)
// store the strongest takeoverproof for the stream in streamer
return err
}