aboutsummaryrefslogtreecommitdiffstats
path: root/eth/handler.go
blob: f22afecb77a5fe5536ec8014839b3ef018f9271d (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
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
// 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/>.

package eth

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

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/eth/downloader"
    "github.com/ethereum/go-ethereum/eth/fetcher"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/pow"
    "github.com/ethereum/go-ethereum/rlp"
)

// This is the target maximum size of returned blocks, headers or node data.
const softResponseLimit = 2 * 1024 * 1024

func errResp(code errCode, format string, v ...interface{}) error {
    return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}

type hashFetcherFn func(common.Hash) error
type blockFetcherFn func([]common.Hash) error

// extProt is an interface which is passed around so we can expose GetHashes and GetBlock without exposing it to the rest of the protocol
// extProt is passed around to peers which require to GetHashes and GetBlocks
type extProt struct {
    getHashes hashFetcherFn
    getBlocks blockFetcherFn
}

func (ep extProt) GetHashes(hash common.Hash) error    { return ep.getHashes(hash) }
func (ep extProt) GetBlock(hashes []common.Hash) error { return ep.getBlocks(hashes) }

type ProtocolManager struct {
    txpool   txPool
    chainman *core.ChainManager
    chaindb  common.Database

    downloader *downloader.Downloader
    fetcher    *fetcher.Fetcher
    peers      *peerSet

    SubProtocols []p2p.Protocol

    eventMux      *event.TypeMux
    txSub         event.Subscription
    minedBlockSub event.Subscription

    // channels for fetcher, syncer, txsyncLoop
    newPeerCh chan *peer
    txsyncCh  chan *txsync
    quitSync  chan struct{}

    // wait group is used for graceful shutdowns during downloading
    // and processing
    wg   sync.WaitGroup
    quit bool
}

// NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
// with the ethereum network.
func NewProtocolManager(networkId int, mux *event.TypeMux, txpool txPool, pow pow.PoW, chainman *core.ChainManager, chaindb common.Database) *ProtocolManager {
    // Create the protocol manager with the base fields
    manager := &ProtocolManager{
        eventMux:  mux,
        txpool:    txpool,
        chainman:  chainman,
        chaindb:   chaindb,
        peers:     newPeerSet(),
        newPeerCh: make(chan *peer, 1),
        txsyncCh:  make(chan *txsync),
        quitSync:  make(chan struct{}),
    }
    // Initiate a sub-protocol for every implemented version we can handle
    manager.SubProtocols = make([]p2p.Protocol, len(ProtocolVersions))
    for i := 0; i < len(manager.SubProtocols); i++ {
        version := ProtocolVersions[i]

        manager.SubProtocols[i] = p2p.Protocol{
            Name:    "eth",
            Version: version,
            Length:  ProtocolLengths[i],
            Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
                peer := manager.newPeer(int(version), networkId, p, rw)
                manager.newPeerCh <- peer
                return manager.handle(peer)
            },
        }
    }
    // Construct the different synchronisation mechanisms
    manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.chainman.CurrentBlock, manager.chainman.InsertChain, manager.removePeer)

    validator := func(block *types.Block, parent *types.Block) error {
        return core.ValidateHeader(pow, block.Header(), parent, true, false)
    }
    heighter := func() uint64 {
        return manager.chainman.CurrentBlock().NumberU64()
    }
    manager.fetcher = fetcher.New(manager.chainman.GetBlock, validator, manager.BroadcastBlock, heighter, manager.chainman.InsertChain, manager.removePeer)

    return manager
}

func (pm *ProtocolManager) removePeer(id string) {
    // Short circuit if the peer was already removed
    peer := pm.peers.Peer(id)
    if peer == nil {
        return
    }
    glog.V(logger.Debug).Infoln("Removing peer", id)

    // Unregister the peer from the downloader and Ethereum peer set
    pm.downloader.UnregisterPeer(id)
    if err := pm.peers.Unregister(id); err != nil {
        glog.V(logger.Error).Infoln("Removal failed:", err)
    }
    // Hard disconnect at the networking layer
    if peer != nil {
        peer.Peer.Disconnect(p2p.DiscUselessPeer)
    }
}

func (pm *ProtocolManager) Start() {
    // broadcast transactions
    pm.txSub = pm.eventMux.Subscribe(core.TxPreEvent{})
    go pm.txBroadcastLoop()
    // broadcast mined blocks
    pm.minedBlockSub = pm.eventMux.Subscribe(core.NewMinedBlockEvent{})
    go pm.minedBroadcastLoop()

    // start sync handlers
    go pm.syncer()
    go pm.txsyncLoop()
}

func (pm *ProtocolManager) Stop() {
    // Showing a log message. During download / process this could actually
    // take between 5 to 10 seconds and therefor feedback is required.
    glog.V(logger.Info).Infoln("Stopping ethereum protocol handler...")

    pm.quit = true
    pm.txSub.Unsubscribe()         // quits txBroadcastLoop
    pm.minedBlockSub.Unsubscribe() // quits blockBroadcastLoop
    close(pm.quitSync)             // quits syncer, fetcher, txsyncLoop

    // Wait for any process action
    pm.wg.Wait()

    glog.V(logger.Info).Infoln("Ethereum protocol handler stopped")
}

func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
    return newPeer(pv, nv, p, newMeteredMsgWriter(rw))
}

// handle is the callback invoked to manage the life cycle of an eth peer. When
// this function terminates, the peer is disconnected.
func (pm *ProtocolManager) handle(p *peer) error {
    glog.V(logger.Debug).Infof("%v: peer connected [%s]", p, p.Name())

    // Execute the Ethereum handshake
    td, head, genesis := pm.chainman.Status()
    if err := p.Handshake(td, head, genesis); err != nil {
        glog.V(logger.Debug).Infof("%v: handshake failed: %v", p, err)
        return err
    }
    if rw, ok := p.rw.(*meteredMsgReadWriter); ok {
        rw.Init(p.version)
    }
    // Register the peer locally
    glog.V(logger.Detail).Infof("%v: adding peer", p)
    if err := pm.peers.Register(p); err != nil {
        glog.V(logger.Error).Infof("%v: addition failed: %v", p, err)
        return err
    }
    defer pm.removePeer(p.id)

    // Register the peer in the downloader. If the downloader considers it banned, we disconnect
    if err := pm.downloader.RegisterPeer(p.id, p.version, p.Head(),
        p.RequestHashes, p.RequestHashesFromNumber, p.RequestBlocks,
        p.RequestHeadersByHash, p.RequestHeadersByNumber, p.RequestBodies); err != nil {
        return err
    }
    // Propagate existing transactions. new transactions appearing
    // after this will be sent via broadcasts.
    pm.syncTransactions(p)

    // main loop. handle incoming messages.
    for {
        if err := pm.handleMsg(p); err != nil {
            glog.V(logger.Debug).Infof("%v: message handling failed: %v", p, err)
            return err
        }
    }
    return nil
}

// handleMsg is invoked whenever an inbound message is received from a remote
// peer. The remote connection is torn down upon returning any error.
func (pm *ProtocolManager) handleMsg(p *peer) error {
    // Read the next message from the remote peer, and ensure it's fully consumed
    msg, err := p.rw.ReadMsg()
    if err != nil {
        return err
    }
    if msg.Size > ProtocolMaxMsgSize {
        return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
    }
    defer msg.Discard()

    // Handle the message depending on its contents
    switch {
    case msg.Code == StatusMsg:
        // Status messages should never arrive after the handshake
        return errResp(ErrExtraStatusMsg, "uncontrolled status message")

    case p.version < eth62 && msg.Code == GetBlockHashesMsg:
        // Retrieve the number of hashes to return and from which origin hash
        var request getBlockHashesData
        if err := msg.Decode(&request); err != nil {
            return errResp(ErrDecode, "%v: %v", msg, err)
        }
        if request.Amount > uint64(downloader.MaxHashFetch) {
            request.Amount = uint64(downloader.MaxHashFetch)
        }
        // Retrieve the hashes from the block chain and return them
        hashes := pm.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)
        if len(hashes) == 0 {
            glog.V(logger.Debug).Infof("invalid block hash %x", request.Hash.Bytes()[:4])
        }
        return p.SendBlockHashes(hashes)

    case p.version < eth62 && msg.Code == GetBlockHashesFromNumberMsg:
        // Retrieve and decode the number of hashes to return and from which origin number
        var request getBlockHashesFromNumberData
        if err := msg.Decode(&request); err != nil {
            return errResp(ErrDecode, "%v: %v", msg, err)
        }
        if request.Amount > uint64(downloader.MaxHashFetch) {
            request.Amount = uint64(downloader.MaxHashFetch)
        }
        // Calculate the last block that should be retrieved, and short circuit if unavailable
        last := pm.chainman.GetBlockByNumber(request.Number + request.Amount - 1)
        if last == nil {
            last = pm.chainman.CurrentBlock()
            request.Amount = last.NumberU64() - request.Number + 1
        }
        if last.NumberU64() < request.Number {
            return p.SendBlockHashes(nil)
        }
        // Retrieve the hashes from the last block backwards, reverse and return
        hashes := []common.Hash{last.Hash()}
        hashes = append(hashes, pm.chainman.GetBlockHashesFromHash(last.Hash(), request.Amount-1)...)

        for i := 0; i < len(hashes)/2; i++ {
            hashes[i], hashes[len(hashes)-1-i] = hashes[len(hashes)-1-i], hashes[i]
        }
        return p.SendBlockHashes(hashes)

    case p.version < eth62 && msg.Code == BlockHashesMsg:
        // A batch of hashes arrived to one of our previous requests
        var hashes []common.Hash
        if err := msg.Decode(&hashes); err != nil {
            break
        }
        // Deliver them all to the downloader for queuing
        err := pm.downloader.DeliverHashes61(p.id, hashes)
        if err != nil {
            glog.V(logger.Debug).Infoln(err)
        }

    case p.version < eth62 && msg.Code == GetBlocksMsg:
        // Decode the retrieval message
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
        if _, err := msgStream.List(); err != nil {
            return err
        }
        // Gather blocks until the fetch or network limits is reached
        var (
            hash   common.Hash
            bytes  common.StorageSize
            blocks []*types.Block
        )
        for len(blocks) < downloader.MaxBlockFetch && bytes < softResponseLimit {
            //Retrieve the hash of the next block
            err := msgStream.Decode(&hash)
            if err == rlp.EOL {
                break
            } else if err != nil {
                return errResp(ErrDecode, "msg %v: %v", msg, err)
            }
            // Retrieve the requested block, stopping if enough was found
            if block := pm.chainman.GetBlock(hash); block != nil {
                blocks = append(blocks, block)
                bytes += block.Size()
            }
        }
        return p.SendBlocks(blocks)

    case p.version < eth62 && msg.Code == BlocksMsg:
        // Decode the arrived block message
        var blocks []*types.Block
        if err := msg.Decode(&blocks); err != nil {
            glog.V(logger.Detail).Infoln("Decode error", err)
            blocks = nil
        }
        // Update the receive timestamp of each block
        for _, block := range blocks {
            block.ReceivedAt = msg.ReceivedAt
        }
        // Filter out any explicitly requested blocks, deliver the rest to the downloader
        if blocks := pm.fetcher.FilterBlocks(blocks); len(blocks) > 0 {
            pm.downloader.DeliverBlocks61(p.id, blocks)
        }

    // Block header query, collect the requested headers and reply
    case p.version >= eth62 && msg.Code == GetBlockHeadersMsg:
        // Decode the complex header query
        var query getBlockHeadersData
        if err := msg.Decode(&query); err != nil {
            return errResp(ErrDecode, "%v: %v", msg, err)
        }
        // Gather blocks until the fetch or network limits is reached
        var (
            bytes   common.StorageSize
            headers []*types.Header
            unknown bool
        )
        for !unknown && len(headers) < int(query.Amount) && bytes < softResponseLimit && len(headers) < downloader.MaxHeaderFetch {
            // Retrieve the next block satisfying the query
            var origin *types.Block
            if query.Origin.Hash != (common.Hash{}) {
                origin = pm.chainman.GetBlock(query.Origin.Hash)
            } else {
                origin = pm.chainman.GetBlockByNumber(query.Origin.Number)
            }
            if origin == nil {
                break
            }
            headers = append(headers, origin.Header())
            bytes += origin.Size()

            // Advance to the next block of the query
            switch {
            case query.Origin.Hash != (common.Hash{}) && query.Reverse:
                // Hash based traversal towards the genesis block
                for i := 0; i < int(query.Skip)+1; i++ {
                    if block := pm.chainman.GetBlock(query.Origin.Hash); block != nil {
                        query.Origin.Hash = block.ParentHash()
                    } else {
                        unknown = true
                        break
                    }
                }
            case query.Origin.Hash != (common.Hash{}) && !query.Reverse:
                // Hash based traversal towards the leaf block
                if block := pm.chainman.GetBlockByNumber(origin.NumberU64() + query.Skip + 1); block != nil {
                    if pm.chainman.GetBlockHashesFromHash(block.Hash(), query.Skip+1)[query.Skip] == query.Origin.Hash {
                        query.Origin.Hash = block.Hash()
                    } else {
                        unknown = true
                    }
                } else {
                    unknown = true
                }
            case query.Reverse:
                // Number based traversal towards the genesis block
                if query.Origin.Number >= query.Skip+1 {
                    query.Origin.Number -= (query.Skip + 1)
                } else {
                    unknown = true
                }

            case !query.Reverse:
                // Number based traversal towards the leaf block
                query.Origin.Number += (query.Skip + 1)
            }
        }
        return p.SendBlockHeaders(headers)

    case p.version >= eth62 && msg.Code == BlockHeadersMsg:
        // A batch of headers arrived to one of our previous requests
        var headers []*types.Header
        if err := msg.Decode(&headers); err != nil {
            return errResp(ErrDecode, "msg %v: %v", msg, err)
        }
        // Filter out any explicitly requested headers, deliver the rest to the downloader
        filter := len(headers) == 1
        if filter {
            headers = pm.fetcher.FilterHeaders(headers, time.Now())
        }
        if len(headers) > 0 || !filter {
            err := pm.downloader.DeliverHeaders(p.id, headers)
            if err != nil {
                glog.V(logger.Debug).Infoln(err)
            }
        }

    case p.version >= eth62 && msg.Code == BlockBodiesMsg:
        // A batch of block bodies arrived to one of our previous requests
        var request blockBodiesData
        if err := msg.Decode(&request); err != nil {
            return errResp(ErrDecode, "msg %v: %v", msg, err)
        }
        // Deliver them all to the downloader for queuing
        trasactions := make([][]*types.Transaction, len(request))
        uncles := make([][]*types.Header, len(request))

        for i, body := range request {
            trasactions[i] = body.Transactions
            uncles[i] = body.Uncles
        }
        // Filter out any explicitly requested bodies, deliver the rest to the downloader
        if trasactions, uncles := pm.fetcher.FilterBodies(trasactions, uncles, time.Now()); len(trasactions) > 0 || len(uncles) > 0 {
            err := pm.downloader.DeliverBodies(p.id, trasactions, uncles)
            if err != nil {
                glog.V(logger.Debug).Infoln(err)
            }
        }

    case p.version >= eth62 && msg.Code == GetBlockBodiesMsg:
        // Decode the retrieval message
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
        if _, err := msgStream.List(); err != nil {
            return err
        }
        // Gather blocks until the fetch or network limits is reached
        var (
            hash   common.Hash
            bytes  common.StorageSize
            bodies []*blockBody
        )
        for bytes < softResponseLimit && len(bodies) < downloader.MaxBlockFetch {
            //Retrieve the hash of the next block
            if err := msgStream.Decode(&hash); err == rlp.EOL {
                break
            } else if err != nil {
                return errResp(ErrDecode, "msg %v: %v", msg, err)
            }
            // Retrieve the requested block, stopping if enough was found
            if block := pm.chainman.GetBlock(hash); block != nil {
                bodies = append(bodies, &blockBody{Transactions: block.Transactions(), Uncles: block.Uncles()})
                bytes += block.Size()
            }
        }
        return p.SendBlockBodies(bodies)

    case p.version >= eth63 && msg.Code == GetNodeDataMsg:
        // Decode the retrieval message
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
        if _, err := msgStream.List(); err != nil {
            return err
        }
        // Gather state data until the fetch or network limits is reached
        var (
            hash  common.Hash
            bytes int
            data  [][]byte
        )
        for bytes < softResponseLimit && len(data) < downloader.MaxStateFetch {
            // Retrieve the hash of the next state entry
            if err := msgStream.Decode(&hash); err == rlp.EOL {
                break
            } else if err != nil {
                return errResp(ErrDecode, "msg %v: %v", msg, err)
            }
            // Retrieve the requested state entry, stopping if enough was found
            if entry, err := pm.chaindb.Get(hash.Bytes()); err == nil {
                data = append(data, entry)
                bytes += len(entry)
            }
        }
        return p.SendNodeData(data)

    case p.version >= eth63 && msg.Code == GetReceiptsMsg:
        // Decode the retrieval message
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
        if _, err := msgStream.List(); err != nil {
            return err
        }
        // Gather state data until the fetch or network limits is reached
        var (
            hash     common.Hash
            bytes    int
            receipts []*types.Receipt
        )
        for bytes < softResponseLimit && len(receipts) < downloader.MaxReceiptsFetch {
            // Retrieve the hash of the next transaction receipt
            if err := msgStream.Decode(&hash); err == rlp.EOL {
                break
            } else if err != nil {
                return errResp(ErrDecode, "msg %v: %v", msg, err)
            }
            // Retrieve the requested receipt, stopping if enough was found
            if receipt := core.GetReceipt(pm.chaindb, hash); receipt != nil {
                receipts = append(receipts, receipt)
                bytes += len(receipt.RlpEncode())
            }
        }
        return p.SendReceipts(receipts)

    case msg.Code == NewBlockHashesMsg:
        // Retrieve and deseralize the remote new block hashes notification
        type announce struct {
            Hash   common.Hash
            Number uint64
        }
        var announces = []announce{}

        if p.version < eth62 {
            // We're running the old protocol, make block number unknown (0)
            var hashes []common.Hash
            if err := msg.Decode(&hashes); err != nil {
                return errResp(ErrDecode, "%v: %v", msg, err)
            }
            for _, hash := range hashes {
                announces = append(announces, announce{hash, 0})
            }
        } else {
            // Otherwise extract both block hash and number
            var request newBlockHashesData
            if err := msg.Decode(&request); err != nil {
                return errResp(ErrDecode, "%v: %v", msg, err)
            }
            for _, block := range request {
                announces = append(announces, announce{block.Hash, block.Number})
            }
        }
        // Mark the hashes as present at the remote node
        for _, block := range announces {
            p.MarkBlock(block.Hash)
            p.SetHead(block.Hash)
        }
        // Schedule all the unknown hashes for retrieval
        unknown := make([]announce, 0, len(announces))
        for _, block := range announces {
            if !pm.chainman.HasBlock(block.Hash) {
                unknown = append(unknown, block)
            }
        }
        for _, block := range unknown {
            if p.version < eth62 {
                pm.fetcher.Notify(p.id, block.Hash, block.Number, time.Now(), p.RequestBlocks, nil, nil)
            } else {
                pm.fetcher.Notify(p.id, block.Hash, block.Number, time.Now(), nil, p.RequestOneHeader, p.RequestBodies)
            }
        }

    case msg.Code == NewBlockMsg:
        // Retrieve and decode the propagated block
        var request newBlockData
        if err := msg.Decode(&request); err != nil {
            return errResp(ErrDecode, "%v: %v", msg, err)
        }
        if err := request.Block.ValidateFields(); err != nil {
            return errResp(ErrDecode, "block validation %v: %v", msg, err)
        }
        request.Block.ReceivedAt = msg.ReceivedAt

        // Mark the block's arrival for whatever reason
        _, chainHead, _ := pm.chainman.Status()
        jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{
            BlockHash:     request.Block.Hash().Hex(),
            BlockNumber:   request.Block.Number(),
            ChainHeadHash: chainHead.Hex(),
            BlockPrevHash: request.Block.ParentHash().Hex(),
            RemoteId:      p.ID().String(),
        })
        // Mark the peer as owning the block and schedule it for import
        p.MarkBlock(request.Block.Hash())
        p.SetHead(request.Block.Hash())

        pm.fetcher.Enqueue(p.id, request.Block)

        // Update the peers total difficulty if needed, schedule a download if gapped
        if request.TD.Cmp(p.Td()) > 0 {
            p.SetTd(request.TD)
            if request.TD.Cmp(new(big.Int).Add(pm.chainman.Td(), request.Block.Difficulty())) > 0 {
                go pm.synchronise(p)
            }
        }

    case msg.Code == TxMsg:
        // Transactions arrived, parse all of them and deliver to the pool
        var txs []*types.Transaction
        if err := msg.Decode(&txs); err != nil {
            return errResp(ErrDecode, "msg %v: %v", msg, err)
        }
        for i, tx := range txs {
            // Validate and mark the remote transaction
            if tx == nil {
                return errResp(ErrDecode, "transaction %d is nil", i)
            }
            p.MarkTransaction(tx.Hash())

            // Log it's arrival for later analysis
            jsonlogger.LogJson(&logger.EthTxReceived{
                TxHash:   tx.Hash().Hex(),
                RemoteId: p.ID().String(),
            })
        }
        pm.txpool.AddTransactions(txs)

    default:
        return errResp(ErrInvalidMsgCode, "%v", msg.Code)
    }
    return nil
}

// BroadcastBlock will either propagate a block to a subset of it's peers, or
// will only announce it's availability (depending what's requested).
func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
    hash := block.Hash()
    peers := pm.peers.PeersWithoutBlock(hash)

    // If propagation is requested, send to a subset of the peer
    if propagate {
        // Calculate the TD of the block (it's not imported yet, so block.Td is not valid)
        var td *big.Int
        if parent := pm.chainman.GetBlock(block.ParentHash()); parent != nil {
            td = new(big.Int).Add(parent.Td, block.Difficulty())
        } else {
            glog.V(logger.Error).Infof("propagating dangling block #%d [%x]", block.NumberU64(), hash[:4])
            return
        }
        // Send the block to a subset of our peers
        transfer := peers[:int(math.Sqrt(float64(len(peers))))]
        for _, peer := range transfer {
            peer.SendNewBlock(block, td)
        }
        glog.V(logger.Detail).Infof("propagated block %x to %d peers in %v", hash[:4], len(transfer), time.Since(block.ReceivedAt))
    }
    // Otherwise if the block is indeed in out own chain, announce it
    if pm.chainman.HasBlock(hash) {
        for _, peer := range peers {
            if peer.version < eth62 {
                peer.SendNewBlockHashes61([]common.Hash{hash})
            } else {
                peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
            }
        }
        glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), time.Since(block.ReceivedAt))
    }
}

// BroadcastTx will propagate a transaction to all peers which are not known to
// already have the given transaction.
func (pm *ProtocolManager) BroadcastTx(hash common.Hash, tx *types.Transaction) {
    // Broadcast transaction to a batch of peers not knowing about it
    peers := pm.peers.PeersWithoutTx(hash)
    //FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
    for _, peer := range peers {
        peer.SendTransactions(types.Transactions{tx})
    }
    glog.V(logger.Detail).Infoln("broadcast tx to", len(peers), "peers")
}

// Mined broadcast loop
func (self *ProtocolManager) minedBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.minedBlockSub.Chan() {
        switch ev := obj.(type) {
        case core.NewMinedBlockEvent:
            self.BroadcastBlock(ev.Block, true)  // First propagate block to peers
            self.BroadcastBlock(ev.Block, false) // Only then announce to the rest
        }
    }
}

func (self *ProtocolManager) txBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.txSub.Chan() {
        event := obj.(core.TxPreEvent)
        self.BroadcastTx(event.Tx.Hash(), event.Tx)
    }
}