aboutsummaryrefslogtreecommitdiffstats
path: root/les/peer.go
blob: 0a8db4975f431c5d652c858dcd8d50d06bfd5507 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
// 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 implements the Light Ethereum Subprotocol.
package les

import (
    "errors"
    "fmt"
    "math/big"
    "sync"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/les/flowcontrol"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/p2p"
    "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 maxHeadInfoLen = 20

type peer struct {
    *p2p.Peer

    rw p2p.MsgReadWriter

    version int // Protocol version negotiated
    network int // Network ID being on

    id string

    headInfo *announceData
    lock     sync.RWMutex

    announceChn chan announceData

    poolEntry *poolEntry
    hasBlock  func(common.Hash, uint64) bool

    fcClient       *flowcontrol.ClientNode // nil if the peer is server only
    fcServer       *flowcontrol.ServerNode // nil if the peer is client only
    fcServerParams *flowcontrol.ServerParams
    fcCosts        requestCostTable
}

func newPeer(version, network int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
    id := p.ID()

    return &peer{
        Peer:        p,
        rw:          rw,
        version:     version,
        network:     network,
        id:          fmt.Sprintf("%x", id[:8]),
        announceChn: make(chan announceData, 20),
    }
}

// Info gathers and returns a collection of metadata known about a peer.
func (p *peer) Info() *eth.PeerInfo {
    return &eth.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 *peer) Head() (hash common.Hash) {
    p.lock.RLock()
    defer p.lock.RUnlock()

    copy(hash[:], p.headInfo.Hash[:])
    return hash
}

func (p *peer) HeadAndTd() (hash common.Hash, td *big.Int) {
    p.lock.RLock()
    defer p.lock.RUnlock()

    copy(hash[:], p.headInfo.Hash[:])
    return hash, p.headInfo.Td
}

func (p *peer) headBlockInfo() blockInfo {
    p.lock.RLock()
    defer p.lock.RUnlock()

    return blockInfo{Hash: p.headInfo.Hash, Number: p.headInfo.Number, Td: p.headInfo.Td}
}

// Td retrieves the current total difficulty of a peer.
func (p *peer) Td() *big.Int {
    p.lock.RLock()
    defer p.lock.RUnlock()

    return new(big.Int).Set(p.headInfo.Td)
}

func sendRequest(w p2p.MsgWriter, msgcode, reqID, cost uint64, data interface{}) error {
    type req struct {
        ReqID uint64
        Data  interface{}
    }
    return p2p.Send(w, msgcode, req{reqID, data})
}

func sendResponse(w p2p.MsgWriter, msgcode, reqID, bv uint64, data interface{}) error {
    type resp struct {
        ReqID, BV uint64
        Data      interface{}
    }
    return p2p.Send(w, msgcode, resp{reqID, bv, data})
}

func (p *peer) GetRequestCost(msgcode uint64, amount int) uint64 {
    p.lock.RLock()
    defer p.lock.RUnlock()

    cost := p.fcCosts[msgcode].baseCost + p.fcCosts[msgcode].reqCost*uint64(amount)
    if cost > p.fcServerParams.BufLimit {
        cost = p.fcServerParams.BufLimit
    }
    return cost
}

// HasBlock checks if the peer has a given block
func (p *peer) HasBlock(hash common.Hash, number uint64) bool {
    p.lock.RLock()
    hashBlock := p.hasBlock
    p.lock.RUnlock()
    return hashBlock != nil && hashBlock(hash, number)
}

// SendAnnounce announces the availability of a number of blocks through
// a hash notification.
func (p *peer) SendAnnounce(request announceData) error {
    return p2p.Send(p.rw, AnnounceMsg, request)
}

// SendBlockHeaders sends a batch of block headers to the remote peer.
func (p *peer) SendBlockHeaders(reqID, bv uint64, headers []*types.Header) error {
    return sendResponse(p.rw, BlockHeadersMsg, reqID, bv, headers)
}

// SendBlockBodiesRLP sends a batch of block contents to the remote peer from
// an already RLP encoded format.
func (p *peer) SendBlockBodiesRLP(reqID, bv uint64, bodies []rlp.RawValue) error {
    return sendResponse(p.rw, BlockBodiesMsg, reqID, bv, bodies)
}

// SendCodeRLP sends a batch of arbitrary internal data, corresponding to the
// hashes requested.
func (p *peer) SendCode(reqID, bv uint64, data [][]byte) error {
    return sendResponse(p.rw, CodeMsg, reqID, bv, data)
}

// SendReceiptsRLP sends a batch of transaction receipts, corresponding to the
// ones requested from an already RLP encoded format.
func (p *peer) SendReceiptsRLP(reqID, bv uint64, receipts []rlp.RawValue) error {
    return sendResponse(p.rw, ReceiptsMsg, reqID, bv, receipts)
}

// SendProofs sends a batch of merkle proofs, corresponding to the ones requested.
func (p *peer) SendProofs(reqID, bv uint64, proofs proofsData) error {
    return sendResponse(p.rw, ProofsMsg, reqID, bv, proofs)
}

// SendHeaderProofs sends a batch of header proofs, corresponding to the ones requested.
func (p *peer) SendHeaderProofs(reqID, bv uint64, proofs []ChtResp) error {
    return sendResponse(p.rw, HeaderProofsMsg, reqID, bv, proofs)
}

// RequestHeadersByHash fetches a batch of blocks' headers corresponding to the
// specified header query, based on the hash of an origin block.
func (p *peer) RequestHeadersByHash(reqID, cost uint64, origin common.Hash, amount int, skip int, reverse bool) error {
    glog.V(logger.Debug).Infof("%v fetching %d headers from %x, skipping %d (reverse = %v)", p, amount, origin[:4], skip, reverse)
    return sendRequest(p.rw, GetBlockHeadersMsg, reqID, cost, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
}

// RequestHeadersByNumber fetches a batch of blocks' headers corresponding to the
// specified header query, based on the number of an origin block.
func (p *peer) RequestHeadersByNumber(reqID, cost, origin uint64, amount int, skip int, reverse bool) error {
    glog.V(logger.Debug).Infof("%v fetching %d headers from #%d, skipping %d (reverse = %v)", p, amount, origin, skip, reverse)
    return sendRequest(p.rw, GetBlockHeadersMsg, reqID, cost, &getBlockHeadersData{Origin: hashOrNumber{Number: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
}

// RequestBodies fetches a batch of blocks' bodies corresponding to the hashes
// specified.
func (p *peer) RequestBodies(reqID, cost uint64, hashes []common.Hash) error {
    glog.V(logger.Debug).Infof("%v fetching %d block bodies", p, len(hashes))
    return sendRequest(p.rw, GetBlockBodiesMsg, reqID, cost, hashes)
}

// RequestCode fetches a batch of arbitrary data from a node's known state
// data, corresponding to the specified hashes.
func (p *peer) RequestCode(reqID, cost uint64, reqs []*CodeReq) error {
    glog.V(logger.Debug).Infof("%v fetching %v state data", p, len(reqs))
    return sendRequest(p.rw, GetCodeMsg, reqID, cost, reqs)
}

// RequestReceipts fetches a batch of transaction receipts from a remote node.
func (p *peer) RequestReceipts(reqID, cost uint64, hashes []common.Hash) error {
    glog.V(logger.Debug).Infof("%v fetching %v receipts", p, len(hashes))
    return sendRequest(p.rw, GetReceiptsMsg, reqID, cost, hashes)
}

// RequestProofs fetches a batch of merkle proofs from a remote node.
func (p *peer) RequestProofs(reqID, cost uint64, reqs []*ProofReq) error {
    glog.V(logger.Debug).Infof("%v fetching %v proofs", p, len(reqs))
    return sendRequest(p.rw, GetProofsMsg, reqID, cost, reqs)
}

// RequestHeaderProofs fetches a batch of header merkle proofs from a remote node.
func (p *peer) RequestHeaderProofs(reqID, cost uint64, reqs []*ChtReq) error {
    glog.V(logger.Debug).Infof("%v fetching %v header proofs", p, len(reqs))
    return sendRequest(p.rw, GetHeaderProofsMsg, reqID, cost, reqs)
}

func (p *peer) SendTxs(cost uint64, txs types.Transactions) error {
    glog.V(logger.Debug).Infof("%v relaying %v txs", p, len(txs))
    p.fcServer.SendRequest(0, cost)
    return p2p.Send(p.rw, SendTxMsg, txs)
}

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 {
    m := make(keyValueMap)
    for _, entry := range l {
        m[entry.Key] = entry.Value
    }
    return m
}

func (m keyValueMap) get(key string, val interface{}) error {
    enc, ok := m[key]
    if !ok {
        return errResp(ErrHandshakeMissingKey, "%s", key)
    }
    if val == nil {
        return nil
    }
    return rlp.DecodeBytes(enc, val)
}

func (p *peer) sendReceiveHandshake(sendList keyValueList) (keyValueList, error) {
    // Send out own handshake in a new thread
    errc := make(chan error, 1)
    go func() {
        errc <- p2p.Send(p.rw, StatusMsg, sendList)
    }()
    // In the mean time retrieve the remote status message
    msg, err := p.rw.ReadMsg()
    if err != nil {
        return nil, err
    }
    if msg.Code != StatusMsg {
        return nil, errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
    }
    if msg.Size > ProtocolMaxMsgSize {
        return nil, errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
    }
    // Decode the handshake
    var recvList keyValueList
    if err := msg.Decode(&recvList); err != nil {
        return nil, errResp(ErrDecode, "msg %v: %v", msg, err)
    }
    if err := <-errc; err != nil {
        return nil, err
    }
    return recvList, nil
}

// Handshake executes the les protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *peer) Handshake(td *big.Int, head common.Hash, headNum uint64, genesis common.Hash, server *LesServer) error {
    p.lock.Lock()
    defer p.lock.Unlock()

    var send keyValueList
    send = send.add("protocolVersion", uint64(p.version))
    send = send.add("networkId", uint64(p.network))
    send = send.add("headTd", td)
    send = send.add("headHash", head)
    send = send.add("headNum", headNum)
    send = send.add("genesisHash", genesis)
    if server != nil {
        send = send.add("serveHeaders", nil)
        send = send.add("serveChainSince", uint64(0))
        send = send.add("serveStateSince", uint64(0))
        send = send.add("txRelay", nil)
        send = send.add("flowControl/BL", server.defParams.BufLimit)
        send = send.add("flowControl/MRR", server.defParams.MinRecharge)
        list := server.fcCostStats.getCurrentList()
        send = send.add("flowControl/MRC", list)
        p.fcCosts = list.decode()
    }
    recvList, err := p.sendReceiveHandshake(send)
    if err != nil {
        return err
    }
    recv := recvList.decode()

    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, genesis)
    }
    if int(rNetwork) != p.network {
        return errResp(ErrNetworkIdMismatch, "%d (!= %d)", rNetwork, p.network)
    }
    if int(rVersion) != p.version {
        return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", rVersion, p.version)
    }
    if server != nil {
        if recv.get("serveStateSince", nil) == nil {
            return errResp(ErrUselessPeer, "wanted client, got server")
        }
        p.fcClient = flowcontrol.NewClientNode(server.fcManager, server.defParams)
    } else {
        if recv.get("serveChainSince", nil) != nil {
            return errResp(ErrUselessPeer, "peer cannot serve chain")
        }
        if recv.get("serveStateSince", nil) != nil {
            return errResp(ErrUselessPeer, "peer cannot serve state")
        }
        if recv.get("txRelay", nil) != nil {
            return errResp(ErrUselessPeer, "peer cannot relay transactions")
        }
        params := &flowcontrol.ServerParams{}
        if err := recv.get("flowControl/BL", &params.BufLimit); err != nil {
            return err
        }
        if err := recv.get("flowControl/MRR", &params.MinRecharge); err != nil {
            return err
        }
        var MRC RequestCostList
        if err := recv.get("flowControl/MRC", &MRC); err != nil {
            return err
        }
        p.fcServerParams = params
        p.fcServer = flowcontrol.NewServerNode(params)
        p.fcCosts = MRC.decode()
    }

    p.headInfo = &announceData{Td: rTd, Hash: rHash, Number: rNum}
    return nil
}

// String implements fmt.Stringer.
func (p *peer) String() string {
    return fmt.Sprintf("Peer %s [%s]", p.id,
        fmt.Sprintf("les/%d", p.version),
    )
}

// peerSet represents the collection of active peers currently participating in
// the Light Ethereum sub-protocol.
type peerSet struct {
    peers  map[string]*peer
    lock   sync.RWMutex
    closed bool
}

// newPeerSet creates a new peer set to track the active participants.
func newPeerSet() *peerSet {
    return &peerSet{
        peers: make(map[string]*peer),
    }
}

// Register injects a new peer into the working set, or returns an error if the
// peer is already known.
func (ps *peerSet) Register(p *peer) error {
    ps.lock.Lock()
    defer ps.lock.Unlock()

    if ps.closed {
        return errClosed
    }
    if _, ok := ps.peers[p.id]; ok {
        return errAlreadyRegistered
    }
    ps.peers[p.id] = p
    return nil
}

// Unregister removes a remote peer from the active set, disabling any further
// actions to/from that particular entity.
func (ps *peerSet) Unregister(id string) error {
    ps.lock.Lock()
    defer ps.lock.Unlock()

    if _, ok := ps.peers[id]; !ok {
        return errNotRegistered
    }
    delete(ps.peers, id)
    return nil
}

// AllPeerIDs returns a list of all registered peer IDs
func (ps *peerSet) AllPeerIDs() []string {
    ps.lock.RLock()
    defer ps.lock.RUnlock()

    res := make([]string, len(ps.peers))
    idx := 0
    for id, _ := range ps.peers {
        res[idx] = id
        idx++
    }
    return res
}

// Peer retrieves the registered peer with the given id.
func (ps *peerSet) Peer(id string) *peer {
    ps.lock.RLock()
    defer ps.lock.RUnlock()

    return ps.peers[id]
}

// Len returns if the current number of peers in the set.
func (ps *peerSet) Len() int {
    ps.lock.RLock()
    defer ps.lock.RUnlock()

    return len(ps.peers)
}

// BestPeer retrieves the known peer with the currently highest total difficulty.
func (ps *peerSet) BestPeer() *peer {
    ps.lock.RLock()
    defer ps.lock.RUnlock()

    var (
        bestPeer *peer
        bestTd   *big.Int
    )
    for _, p := range ps.peers {
        if td := p.Td(); bestPeer == nil || td.Cmp(bestTd) > 0 {
            bestPeer, bestTd = p, td
        }
    }
    return bestPeer
}

// AllPeers returns all peers in a list
func (ps *peerSet) AllPeers() []*peer {
    ps.lock.RLock()
    defer ps.lock.RUnlock()

    list := make([]*peer, len(ps.peers))
    i := 0
    for _, peer := range ps.peers {
        list[i] = peer
        i++
    }
    return list
}

// Close disconnects all peers.
// No new peers can be registered after Close has returned.
func (ps *peerSet) Close() {
    ps.lock.Lock()
    defer ps.lock.Unlock()

    for _, p := range ps.peers {
        p.Disconnect(p2p.DiscQuitting)
    }
    ps.closed = true
}