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peer.go
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peer.go
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// Copyright 2016 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 les
import (
"errors"
"fmt"
"math/big"
"math/rand"
"net"
"sync"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/eth"
"github.com/ethereum/go-ethereum/les/flowcontrol"
lpc "github.com/ethereum/go-ethereum/les/lespay/client"
"github.com/ethereum/go-ethereum/les/utils"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
)
var (
errClosed = errors.New("peer set is closed")
errAlreadyRegistered = errors.New("peer is already registered")
errNotRegistered = errors.New("peer is not registered")
)
const (
maxRequestErrors = 20 // number of invalid requests tolerated (makes the protocol less brittle but still avoids spam)
maxResponseErrors = 50 // number of invalid responses tolerated (makes the protocol less brittle but still avoids spam)
allowedUpdateBytes = 100000 // initial/maximum allowed update size
allowedUpdateRate = time.Millisecond * 10 // time constant for recharging one byte of allowance
freezeTimeBase = time.Millisecond * 700 // fixed component of client freeze time
freezeTimeRandom = time.Millisecond * 600 // random component of client freeze time
freezeCheckPeriod = time.Millisecond * 100 // buffer value recheck period after initial freeze time has elapsed
// If the total encoded size of a sent transaction batch is over txSizeCostLimit
// per transaction then the request cost is calculated as proportional to the
// encoded size instead of the transaction count
txSizeCostLimit = 0x4000
// handshakeTimeout is the timeout LES handshake will be treated as failed.
handshakeTimeout = 5 * time.Second
// retrySendCachePeriod is the time interval a caching retry is performed.
retrySendCachePeriod = time.Millisecond * 100
)
const (
announceTypeNone = iota
announceTypeSimple
announceTypeSigned
)
type keyValueEntry struct {
Key string
Value rlp.RawValue
}
type keyValueList []keyValueEntry
type keyValueMap map[string]rlp.RawValue
func (l keyValueList) add(key string, val interface{}) keyValueList {
var entry keyValueEntry
entry.Key = key
if val == nil {
val = uint64(0)
}
enc, err := rlp.EncodeToBytes(val)
if err == nil {
entry.Value = enc
}
return append(l, entry)
}
func (l keyValueList) decode() (keyValueMap, uint64) {
m := make(keyValueMap)
var size uint64
for _, entry := range l {
m[entry.Key] = entry.Value
size += uint64(len(entry.Key)) + uint64(len(entry.Value)) + 8
}
return m, size
}
func (m keyValueMap) get(key string, val interface{}) error {
enc, ok := m[key]
if !ok {
return errResp(ErrMissingKey, "%s", key)
}
if val == nil {
return nil
}
return rlp.DecodeBytes(enc, val)
}
// peerIdToString converts enode.ID to a string form
func peerIdToString(id enode.ID) string {
return fmt.Sprintf("%x", id.Bytes())
}
// peerCommons contains fields needed by both server peer and client peer.
type peerCommons struct {
*p2p.Peer
rw p2p.MsgReadWriter
id string // Peer identity.
version int // Protocol version negotiated.
network uint64 // Network ID being on.
frozen uint32 // Flag whether the peer is frozen.
announceType uint64 // New block announcement type.
serving uint32 // The status indicates the peer is served.
headInfo blockInfo // Latest block information.
// Background task queue for caching peer tasks and executing in order.
sendQueue *utils.ExecQueue
// Flow control agreement.
fcParams flowcontrol.ServerParams // The config for token bucket.
fcCosts requestCostTable // The Maximum request cost table.
closeCh chan struct{}
lock sync.RWMutex // Lock used to protect all thread-sensitive fields.
}
// isFrozen returns true if the client is frozen or the server has put our
// client in frozen state
func (p *peerCommons) isFrozen() bool {
return atomic.LoadUint32(&p.frozen) != 0
}
// canQueue returns an indicator whether the peer can queue a operation.
func (p *peerCommons) canQueue() bool {
return p.sendQueue.CanQueue() && !p.isFrozen()
}
// queueSend caches a peer operation in the background task queue.
// Please ensure to check `canQueue` before call this function
func (p *peerCommons) queueSend(f func()) bool {
return p.sendQueue.Queue(f)
}
// mustQueueSend starts a for loop and retry the caching if failed.
// If the stopCh is closed, then it returns.
func (p *peerCommons) mustQueueSend(f func()) {
for {
// Check whether the stopCh is closed.
select {
case <-p.closeCh:
return
default:
}
// If the function is successfully cached, return.
if p.canQueue() && p.queueSend(f) {
return
}
time.Sleep(retrySendCachePeriod)
}
}
// String implements fmt.Stringer.
func (p *peerCommons) String() string {
return fmt.Sprintf("Peer %s [%s]", p.id, fmt.Sprintf("les/%d", p.version))
}
// Info gathers and returns a collection of metadata known about a peer.
func (p *peerCommons) Info() *eth.PeerInfo {
return ð.PeerInfo{
Version: p.version,
Difficulty: p.Td(),
Head: fmt.Sprintf("%x", p.Head()),
}
}
// Head retrieves a copy of the current head (most recent) hash of the peer.
func (p *peerCommons) Head() (hash common.Hash) {
p.lock.RLock()
defer p.lock.RUnlock()
return p.headInfo.Hash
}
// Td retrieves the current total difficulty of a peer.
func (p *peerCommons) Td() *big.Int {
p.lock.RLock()
defer p.lock.RUnlock()
return new(big.Int).Set(p.headInfo.Td)
}
// HeadAndTd retrieves the current head hash and total difficulty of a peer.
func (p *peerCommons) HeadAndTd() (hash common.Hash, td *big.Int) {
p.lock.RLock()
defer p.lock.RUnlock()
return p.headInfo.Hash, new(big.Int).Set(p.headInfo.Td)
}
// sendReceiveHandshake exchanges handshake packet with remote peer and returns any error
// if failed to send or receive packet.
func (p *peerCommons) sendReceiveHandshake(sendList keyValueList) (keyValueList, error) {
var (
errc = make(chan error, 2)
recvList keyValueList
)
// Send out own handshake in a new thread
go func() {
errc <- p2p.Send(p.rw, StatusMsg, sendList)
}()
go func() {
// In the mean time retrieve the remote status message
msg, err := p.rw.ReadMsg()
if err != nil {
errc <- err
return
}
if msg.Code != StatusMsg {
errc <- errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
return
}
if msg.Size > ProtocolMaxMsgSize {
errc <- errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
return
}
// Decode the handshake
if err := msg.Decode(&recvList); err != nil {
errc <- errResp(ErrDecode, "msg %v: %v", msg, err)
return
}
errc <- nil
}()
timeout := time.NewTimer(handshakeTimeout)
defer timeout.Stop()
for i := 0; i < 2; i++ {
select {
case err := <-errc:
if err != nil {
return nil, err
}
case <-timeout.C:
return nil, p2p.DiscReadTimeout
}
}
return recvList, nil
}
// handshake executes the les protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks. Besides the basic handshake
// fields, server and client can exchange and resolve some specified fields through
// two callback functions.
func (p *peerCommons) handshake(td *big.Int, head common.Hash, headNum uint64, genesis common.Hash, sendCallback func(*keyValueList), recvCallback func(keyValueMap) error) error {
p.lock.Lock()
defer p.lock.Unlock()
var send keyValueList
// Add some basic handshake fields
send = send.add("protocolVersion", uint64(p.version))
send = send.add("networkId", p.network)
send = send.add("headTd", td)
send = send.add("headHash", head)
send = send.add("headNum", headNum)
send = send.add("genesisHash", genesis)
// Add client-specified or server-specified fields
if sendCallback != nil {
sendCallback(&send)
}
// Exchange the handshake packet and resolve the received one.
recvList, err := p.sendReceiveHandshake(send)
if err != nil {
return err
}
recv, size := recvList.decode()
if size > allowedUpdateBytes {
return errResp(ErrRequestRejected, "")
}
var rGenesis, rHash common.Hash
var rVersion, rNetwork, rNum uint64
var rTd *big.Int
if err := recv.get("protocolVersion", &rVersion); err != nil {
return err
}
if err := recv.get("networkId", &rNetwork); err != nil {
return err
}
if err := recv.get("headTd", &rTd); err != nil {
return err
}
if err := recv.get("headHash", &rHash); err != nil {
return err
}
if err := recv.get("headNum", &rNum); err != nil {
return err
}
if err := recv.get("genesisHash", &rGenesis); err != nil {
return err
}
if rGenesis != genesis {
return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", rGenesis[:8], genesis[:8])
}
if rNetwork != p.network {
return errResp(ErrNetworkIdMismatch, "%d (!= %d)", rNetwork, p.network)
}
if int(rVersion) != p.version {
return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", rVersion, p.version)
}
p.headInfo = blockInfo{Hash: rHash, Number: rNum, Td: rTd}
if recvCallback != nil {
return recvCallback(recv)
}
return nil
}
// close closes the channel and notifies all background routines to exit.
func (p *peerCommons) close() {
close(p.closeCh)
p.sendQueue.Quit()
}
// serverPeer represents each node to which the client is connected.
// The node here refers to the les server.
type serverPeer struct {
peerCommons
// Status fields
trusted bool // The flag whether the server is selected as trusted server.
onlyAnnounce bool // The flag whether the server sends announcement only.
chainSince, chainRecent uint64 // The range of chain server peer can serve.
stateSince, stateRecent uint64 // The range of state server peer can serve.
// Advertised checkpoint fields
checkpointNumber uint64 // The block height which the checkpoint is registered.
checkpoint params.TrustedCheckpoint // The advertised checkpoint sent by server.
poolEntry *poolEntry // Statistic for server peer.
fcServer *flowcontrol.ServerNode // Client side mirror token bucket.
vtLock sync.Mutex
valueTracker *lpc.ValueTracker
nodeValueTracker *lpc.NodeValueTracker
sentReqs map[uint64]sentReqEntry
// Statistics
errCount int // Counter the invalid responses server has replied
updateCount uint64
updateTime mclock.AbsTime
// Callbacks
hasBlock func(common.Hash, uint64, bool) bool // Used to determine whether the server has the specified block.
}
func newServerPeer(version int, network uint64, trusted bool, p *p2p.Peer, rw p2p.MsgReadWriter) *serverPeer {
return &serverPeer{
peerCommons: peerCommons{
Peer: p,
rw: rw,
id: peerIdToString(p.ID()),
version: version,
network: network,
sendQueue: utils.NewExecQueue(100),
closeCh: make(chan struct{}),
},
trusted: trusted,
}
}
// rejectUpdate returns true if a parameter update has to be rejected because
// the size and/or rate of updates exceed the capacity limitation
func (p *serverPeer) rejectUpdate(size uint64) bool {
now := mclock.Now()
if p.updateCount == 0 {
p.updateTime = now
} else {
dt := now - p.updateTime
p.updateTime = now
r := uint64(dt / mclock.AbsTime(allowedUpdateRate))
if p.updateCount > r {
p.updateCount -= r
} else {
p.updateCount = 0
}
}
p.updateCount += size
return p.updateCount > allowedUpdateBytes
}
// freeze processes Stop messages from the given server and set the status as
// frozen.
func (p *serverPeer) freeze() {
if atomic.CompareAndSwapUint32(&p.frozen, 0, 1) {
p.sendQueue.Clear()
}
}
// unfreeze processes Resume messages from the given server and set the status
// as unfrozen.
func (p *serverPeer) unfreeze() {
atomic.StoreUint32(&p.frozen, 0)
}
// sendRequest send a request to the server based on the given message type
// and content.
func sendRequest(w p2p.MsgWriter, msgcode, reqID uint64, data interface{}) error {
type req struct {
ReqID uint64
Data interface{}
}
return p2p.Send(w, msgcode, req{reqID, data})
}
func (p *serverPeer) sendRequest(msgcode, reqID uint64, data interface{}, amount int) error {
p.sentRequest(reqID, uint32(msgcode), uint32(amount))
return sendRequest(p.rw, msgcode, reqID, data)
}
// requestHeadersByHash fetches a batch of blocks' headers corresponding to the
// specified header query, based on the hash of an origin block.
func (p *serverPeer) requestHeadersByHash(reqID uint64, origin common.Hash, amount int, skip int, reverse bool) error {
p.Log().Debug("Fetching batch of headers", "count", amount, "fromhash", origin, "skip", skip, "reverse", reverse)
return p.sendRequest(GetBlockHeadersMsg, reqID, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse}, amount)
}
// requestHeadersByNumber fetches a batch of blocks' headers corresponding to the
// specified header query, based on the number of an origin block.
func (p *serverPeer) requestHeadersByNumber(reqID, origin uint64, amount int, skip int, reverse bool) error {
p.Log().Debug("Fetching batch of headers", "count", amount, "fromnum", origin, "skip", skip, "reverse", reverse)
return p.sendRequest(GetBlockHeadersMsg, reqID, &getBlockHeadersData{Origin: hashOrNumber{Number: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse}, amount)
}
// requestBodies fetches a batch of blocks' bodies corresponding to the hashes
// specified.
func (p *serverPeer) requestBodies(reqID uint64, hashes []common.Hash) error {
p.Log().Debug("Fetching batch of block bodies", "count", len(hashes))
return p.sendRequest(GetBlockBodiesMsg, reqID, hashes, len(hashes))
}
// requestCode fetches a batch of arbitrary data from a node's known state
// data, corresponding to the specified hashes.
func (p *serverPeer) requestCode(reqID uint64, reqs []CodeReq) error {
p.Log().Debug("Fetching batch of codes", "count", len(reqs))
return p.sendRequest(GetCodeMsg, reqID, reqs, len(reqs))
}
// requestReceipts fetches a batch of transaction receipts from a remote node.
func (p *serverPeer) requestReceipts(reqID uint64, hashes []common.Hash) error {
p.Log().Debug("Fetching batch of receipts", "count", len(hashes))
return p.sendRequest(GetReceiptsMsg, reqID, hashes, len(hashes))
}
// requestProofs fetches a batch of merkle proofs from a remote node.
func (p *serverPeer) requestProofs(reqID uint64, reqs []ProofReq) error {
p.Log().Debug("Fetching batch of proofs", "count", len(reqs))
return p.sendRequest(GetProofsV2Msg, reqID, reqs, len(reqs))
}
// requestHelperTrieProofs fetches a batch of HelperTrie merkle proofs from a remote node.
func (p *serverPeer) requestHelperTrieProofs(reqID uint64, reqs []HelperTrieReq) error {
p.Log().Debug("Fetching batch of HelperTrie proofs", "count", len(reqs))
return p.sendRequest(GetHelperTrieProofsMsg, reqID, reqs, len(reqs))
}
// requestTxStatus fetches a batch of transaction status records from a remote node.
func (p *serverPeer) requestTxStatus(reqID uint64, txHashes []common.Hash) error {
p.Log().Debug("Requesting transaction status", "count", len(txHashes))
return p.sendRequest(GetTxStatusMsg, reqID, txHashes, len(txHashes))
}
// SendTxStatus creates a reply with a batch of transactions to be added to the remote transaction pool.
func (p *serverPeer) sendTxs(reqID uint64, amount int, txs rlp.RawValue) error {
p.Log().Debug("Sending batch of transactions", "amount", amount, "size", len(txs))
sizeFactor := (len(txs) + txSizeCostLimit/2) / txSizeCostLimit
if sizeFactor > amount {
amount = sizeFactor
}
return p.sendRequest(SendTxV2Msg, reqID, txs, amount)
}
// waitBefore implements distPeer interface
func (p *serverPeer) waitBefore(maxCost uint64) (time.Duration, float64) {
return p.fcServer.CanSend(maxCost)
}
// getRequestCost returns an estimated request cost according to the flow control
// rules negotiated between the server and the client.
func (p *serverPeer) getRequestCost(msgcode uint64, amount int) uint64 {
p.lock.RLock()
defer p.lock.RUnlock()
costs := p.fcCosts[msgcode]
if costs == nil {
return 0
}
cost := costs.baseCost + costs.reqCost*uint64(amount)
if cost > p.fcParams.BufLimit {
cost = p.fcParams.BufLimit
}
return cost
}
// getTxRelayCost returns an estimated relay cost according to the flow control
// rules negotiated between the server and the client.
func (p *serverPeer) getTxRelayCost(amount, size int) uint64 {
p.lock.RLock()
defer p.lock.RUnlock()
costs := p.fcCosts[SendTxV2Msg]
if costs == nil {
return 0
}
cost := costs.baseCost + costs.reqCost*uint64(amount)
sizeCost := costs.baseCost + costs.reqCost*uint64(size)/txSizeCostLimit
if sizeCost > cost {
cost = sizeCost
}
if cost > p.fcParams.BufLimit {
cost = p.fcParams.BufLimit
}
return cost
}
// HasBlock checks if the peer has a given block
func (p *serverPeer) HasBlock(hash common.Hash, number uint64, hasState bool) bool {
p.lock.RLock()
head := p.headInfo.Number
var since, recent uint64
if hasState {
since = p.stateSince
recent = p.stateRecent
} else {
since = p.chainSince
recent = p.chainRecent
}
hasBlock := p.hasBlock
p.lock.RUnlock()
return head >= number && number >= since && (recent == 0 || number+recent+4 > head) && hasBlock != nil && hasBlock(hash, number, hasState)
}
// updateFlowControl updates the flow control parameters belonging to the server
// node if the announced key/value set contains relevant fields
func (p *serverPeer) updateFlowControl(update keyValueMap) {
p.lock.Lock()
defer p.lock.Unlock()
// If any of the flow control params is nil, refuse to update.
var params flowcontrol.ServerParams
if update.get("flowControl/BL", ¶ms.BufLimit) == nil && update.get("flowControl/MRR", ¶ms.MinRecharge) == nil {
// todo can light client set a minimal acceptable flow control params?
p.fcParams = params
p.fcServer.UpdateParams(params)
}
var MRC RequestCostList
if update.get("flowControl/MRC", &MRC) == nil {
costUpdate := MRC.decode(ProtocolLengths[uint(p.version)])
for code, cost := range costUpdate {
p.fcCosts[code] = cost
}
}
}
// Handshake executes the les protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *serverPeer) Handshake(td *big.Int, head common.Hash, headNum uint64, genesis common.Hash, server *LesServer) error {
return p.handshake(td, head, headNum, genesis, func(lists *keyValueList) {
// Add some client-specific handshake fields
//
// Enable signed announcement randomly even the server is not trusted.
p.announceType = announceTypeSimple
if p.trusted {
p.announceType = announceTypeSigned
}
*lists = (*lists).add("announceType", p.announceType)
}, func(recv keyValueMap) error {
if recv.get("serveChainSince", &p.chainSince) != nil {
p.onlyAnnounce = true
}
if recv.get("serveRecentChain", &p.chainRecent) != nil {
p.chainRecent = 0
}
if recv.get("serveStateSince", &p.stateSince) != nil {
p.onlyAnnounce = true
}
if recv.get("serveRecentState", &p.stateRecent) != nil {
p.stateRecent = 0
}
if recv.get("txRelay", nil) != nil {
p.onlyAnnounce = true
}
if p.onlyAnnounce && !p.trusted {
return errResp(ErrUselessPeer, "peer cannot serve requests")
}
// Parse flow control handshake packet.
var sParams flowcontrol.ServerParams
if err := recv.get("flowControl/BL", &sParams.BufLimit); err != nil {
return err
}
if err := recv.get("flowControl/MRR", &sParams.MinRecharge); err != nil {
return err
}
var MRC RequestCostList
if err := recv.get("flowControl/MRC", &MRC); err != nil {
return err
}
p.fcParams = sParams
p.fcServer = flowcontrol.NewServerNode(sParams, &mclock.System{})
p.fcCosts = MRC.decode(ProtocolLengths[uint(p.version)])
recv.get("checkpoint/value", &p.checkpoint)
recv.get("checkpoint/registerHeight", &p.checkpointNumber)
if !p.onlyAnnounce {
for msgCode := range reqAvgTimeCost {
if p.fcCosts[msgCode] == nil {
return errResp(ErrUselessPeer, "peer does not support message %d", msgCode)
}
}
}
return nil
})
}
// setValueTracker sets the value tracker references for connected servers. Note that the
// references should be removed upon disconnection by setValueTracker(nil, nil).
func (p *serverPeer) setValueTracker(vt *lpc.ValueTracker, nvt *lpc.NodeValueTracker) {
p.vtLock.Lock()
p.valueTracker = vt
p.nodeValueTracker = nvt
if nvt != nil {
p.sentReqs = make(map[uint64]sentReqEntry)
} else {
p.sentReqs = nil
}
p.vtLock.Unlock()
}
// updateVtParams updates the server's price table in the value tracker.
func (p *serverPeer) updateVtParams() {
p.vtLock.Lock()
defer p.vtLock.Unlock()
if p.nodeValueTracker == nil {
return
}
reqCosts := make([]uint64, len(requestList))
for code, costs := range p.fcCosts {
if m, ok := requestMapping[uint32(code)]; ok {
reqCosts[m.first] = costs.baseCost + costs.reqCost
if m.rest != -1 {
reqCosts[m.rest] = costs.reqCost
}
}
}
p.valueTracker.UpdateCosts(p.nodeValueTracker, reqCosts)
}
// sentReqEntry remembers sent requests and their sending times
type sentReqEntry struct {
reqType, amount uint32
at mclock.AbsTime
}
// sentRequest marks a request sent at the current moment to this server.
func (p *serverPeer) sentRequest(id uint64, reqType, amount uint32) {
p.vtLock.Lock()
if p.sentReqs != nil {
p.sentReqs[id] = sentReqEntry{reqType, amount, mclock.Now()}
}
p.vtLock.Unlock()
}
// answeredRequest marks a request answered at the current moment by this server.
func (p *serverPeer) answeredRequest(id uint64) {
p.vtLock.Lock()
if p.sentReqs == nil {
p.vtLock.Unlock()
return
}
e, ok := p.sentReqs[id]
delete(p.sentReqs, id)
vt := p.valueTracker
nvt := p.nodeValueTracker
p.vtLock.Unlock()
if !ok {
return
}
var (
vtReqs [2]lpc.ServedRequest
reqCount int
)
m := requestMapping[e.reqType]
if m.rest == -1 || e.amount <= 1 {
reqCount = 1
vtReqs[0] = lpc.ServedRequest{ReqType: uint32(m.first), Amount: e.amount}
} else {
reqCount = 2
vtReqs[0] = lpc.ServedRequest{ReqType: uint32(m.first), Amount: 1}
vtReqs[1] = lpc.ServedRequest{ReqType: uint32(m.rest), Amount: e.amount - 1}
}
dt := time.Duration(mclock.Now() - e.at)
vt.Served(nvt, vtReqs[:reqCount], dt)
}
// clientPeer represents each node to which the les server is connected.
// The node here refers to the light client.
type clientPeer struct {
peerCommons
// responseLock ensures that responses are queued in the same order as
// RequestProcessed is called
responseLock sync.Mutex
server bool
invalidCount uint32 // Counter the invalid request the client peer has made.
responseCount uint64 // Counter to generate an unique id for request processing.
errCh chan error
fcClient *flowcontrol.ClientNode // Server side mirror token bucket.
}
func newClientPeer(version int, network uint64, p *p2p.Peer, rw p2p.MsgReadWriter) *clientPeer {
return &clientPeer{
peerCommons: peerCommons{
Peer: p,
rw: rw,
id: peerIdToString(p.ID()),
version: version,
network: network,
sendQueue: utils.NewExecQueue(100),
closeCh: make(chan struct{}),
},
errCh: make(chan error, 1),
}
}
// freeClientId returns a string identifier for the peer. Multiple peers with
// the same identifier can not be connected in free mode simultaneously.
func (p *clientPeer) freeClientId() string {
if addr, ok := p.RemoteAddr().(*net.TCPAddr); ok {
if addr.IP.IsLoopback() {
// using peer id instead of loopback ip address allows multiple free
// connections from local machine to own server
return p.id
} else {
return addr.IP.String()
}
}
return p.id
}
// sendStop notifies the client about being in frozen state
func (p *clientPeer) sendStop() error {
return p2p.Send(p.rw, StopMsg, struct{}{})
}
// sendResume notifies the client about getting out of frozen state
func (p *clientPeer) sendResume(bv uint64) error {
return p2p.Send(p.rw, ResumeMsg, bv)
}
// freeze temporarily puts the client in a frozen state which means all unprocessed
// and subsequent requests are dropped. Unfreezing happens automatically after a short
// time if the client's buffer value is at least in the slightly positive region.
// The client is also notified about being frozen/unfrozen with a Stop/Resume message.
func (p *clientPeer) freeze() {
if p.version < lpv3 {
// if Stop/Resume is not supported then just drop the peer after setting
// its frozen status permanently
atomic.StoreUint32(&p.frozen, 1)
p.Peer.Disconnect(p2p.DiscUselessPeer)
return
}
if atomic.SwapUint32(&p.frozen, 1) == 0 {
go func() {
p.sendStop()
time.Sleep(freezeTimeBase + time.Duration(rand.Int63n(int64(freezeTimeRandom))))
for {
bufValue, bufLimit := p.fcClient.BufferStatus()
if bufLimit == 0 {
return
}
if bufValue <= bufLimit/8 {
time.Sleep(freezeCheckPeriod)
continue
}
atomic.StoreUint32(&p.frozen, 0)
p.sendResume(bufValue)
return
}
}()
}
}
// reply struct represents a reply with the actual data already RLP encoded and
// only the bv (buffer value) missing. This allows the serving mechanism to
// calculate the bv value which depends on the data size before sending the reply.
type reply struct {
w p2p.MsgWriter
msgcode, reqID uint64
data rlp.RawValue
}
// send sends the reply with the calculated buffer value
func (r *reply) send(bv uint64) error {
type resp struct {
ReqID, BV uint64
Data rlp.RawValue
}
return p2p.Send(r.w, r.msgcode, resp{r.reqID, bv, r.data})
}
// size returns the RLP encoded size of the message data
func (r *reply) size() uint32 {
return uint32(len(r.data))
}
// replyBlockHeaders creates a reply with a batch of block headers
func (p *clientPeer) replyBlockHeaders(reqID uint64, headers []*types.Header) *reply {
data, _ := rlp.EncodeToBytes(headers)
return &reply{p.rw, BlockHeadersMsg, reqID, data}
}
// replyBlockBodiesRLP creates a reply with a batch of block contents from
// an already RLP encoded format.
func (p *clientPeer) replyBlockBodiesRLP(reqID uint64, bodies []rlp.RawValue) *reply {
data, _ := rlp.EncodeToBytes(bodies)
return &reply{p.rw, BlockBodiesMsg, reqID, data}
}
// replyCode creates a reply with a batch of arbitrary internal data, corresponding to the
// hashes requested.
func (p *clientPeer) replyCode(reqID uint64, codes [][]byte) *reply {
data, _ := rlp.EncodeToBytes(codes)
return &reply{p.rw, CodeMsg, reqID, data}
}
// replyReceiptsRLP creates a reply with a batch of transaction receipts, corresponding to the
// ones requested from an already RLP encoded format.
func (p *clientPeer) replyReceiptsRLP(reqID uint64, receipts []rlp.RawValue) *reply {
data, _ := rlp.EncodeToBytes(receipts)
return &reply{p.rw, ReceiptsMsg, reqID, data}
}
// replyProofsV2 creates a reply with a batch of merkle proofs, corresponding to the ones requested.
func (p *clientPeer) replyProofsV2(reqID uint64, proofs light.NodeList) *reply {
data, _ := rlp.EncodeToBytes(proofs)
return &reply{p.rw, ProofsV2Msg, reqID, data}
}
// replyHelperTrieProofs creates a reply with a batch of HelperTrie proofs, corresponding to the ones requested.
func (p *clientPeer) replyHelperTrieProofs(reqID uint64, resp HelperTrieResps) *reply {
data, _ := rlp.EncodeToBytes(resp)
return &reply{p.rw, HelperTrieProofsMsg, reqID, data}
}
// replyTxStatus creates a reply with a batch of transaction status records, corresponding to the ones requested.
func (p *clientPeer) replyTxStatus(reqID uint64, stats []light.TxStatus) *reply {
data, _ := rlp.EncodeToBytes(stats)
return &reply{p.rw, TxStatusMsg, reqID, data}
}
// sendAnnounce announces the availability of a number of blocks through
// a hash notification.
func (p *clientPeer) sendAnnounce(request announceData) error {
return p2p.Send(p.rw, AnnounceMsg, request)
}
// updateCapacity updates the request serving capacity assigned to a given client
// and also sends an announcement about the updated flow control parameters
func (p *clientPeer) updateCapacity(cap uint64) {
p.lock.Lock()
defer p.lock.Unlock()
p.fcParams = flowcontrol.ServerParams{MinRecharge: cap, BufLimit: cap * bufLimitRatio}
p.fcClient.UpdateParams(p.fcParams)
var kvList keyValueList
kvList = kvList.add("flowControl/MRR", cap)
kvList = kvList.add("flowControl/BL", cap*bufLimitRatio)
p.mustQueueSend(func() { p.sendAnnounce(announceData{Update: kvList}) })
}
// freezeClient temporarily puts the client in a frozen state which means all
// unprocessed and subsequent requests are dropped. Unfreezing happens automatically
// after a short time if the client's buffer value is at least in the slightly positive
// region. The client is also notified about being frozen/unfrozen with a Stop/Resume
// message.
func (p *clientPeer) freezeClient() {
if p.version < lpv3 {
// if Stop/Resume is not supported then just drop the peer after setting
// its frozen status permanently
atomic.StoreUint32(&p.frozen, 1)
p.Peer.Disconnect(p2p.DiscUselessPeer)
return
}
if atomic.SwapUint32(&p.frozen, 1) == 0 {
go func() {
p.sendStop()
time.Sleep(freezeTimeBase + time.Duration(rand.Int63n(int64(freezeTimeRandom))))
for {
bufValue, bufLimit := p.fcClient.BufferStatus()
if bufLimit == 0 {
return
}
if bufValue <= bufLimit/8 {
time.Sleep(freezeCheckPeriod)
} else {
atomic.StoreUint32(&p.frozen, 0)
p.sendResume(bufValue)
break
}
}
}()
}
}
// Handshake executes the les protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *clientPeer) Handshake(td *big.Int, head common.Hash, headNum uint64, genesis common.Hash, server *LesServer) error {
return p.handshake(td, head, headNum, genesis, func(lists *keyValueList) {
// Add some information which services server can offer.
if !server.config.UltraLightOnlyAnnounce {
*lists = (*lists).add("serveHeaders", nil)
*lists = (*lists).add("serveChainSince", uint64(0))
*lists = (*lists).add("serveStateSince", uint64(0))
// If local ethereum node is running in archive mode, advertise ourselves we have
// all version state data. Otherwise only recent state is available.
stateRecent := uint64(core.TriesInMemory - 4)
if server.archiveMode {
stateRecent = 0
}
*lists = (*lists).add("serveRecentState", stateRecent)
*lists = (*lists).add("txRelay", nil)
}
*lists = (*lists).add("flowControl/BL", server.defParams.BufLimit)
*lists = (*lists).add("flowControl/MRR", server.defParams.MinRecharge)
var costList RequestCostList
if server.costTracker.testCostList != nil {
costList = server.costTracker.testCostList
} else {
costList = server.costTracker.makeCostList(server.costTracker.globalFactor())
}
*lists = (*lists).add("flowControl/MRC", costList)
p.fcCosts = costList.decode(ProtocolLengths[uint(p.version)])
p.fcParams = server.defParams
// Add advertised checkpoint and register block height which
// client can verify the checkpoint validity.
if server.oracle != nil && server.oracle.IsRunning() {
cp, height := server.oracle.StableCheckpoint()
if cp != nil {
*lists = (*lists).add("checkpoint/value", cp)
*lists = (*lists).add("checkpoint/registerHeight", height)
}
}
}, func(recv keyValueMap) error {
p.server = recv.get("flowControl/MRR", nil) == nil
if p.server {
p.announceType = announceTypeNone // connected to another server, send no messages
} else {
if recv.get("announceType", &p.announceType) != nil {
// set default announceType on server side
p.announceType = announceTypeSimple
}
p.fcClient = flowcontrol.NewClientNode(server.fcManager, server.defParams)
}
return nil
})
}
// serverPeerSubscriber is an interface to notify services about added or
// removed server peers
type serverPeerSubscriber interface {
registerPeer(*serverPeer)
unregisterPeer(*serverPeer)
}