aboutsummaryrefslogtreecommitdiffstats
path: root/eth/handler.go
blob: a5986b779c97274f8d0eab03e40299493e2cc14e (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
package eth

import (
    "fmt"
    "math"
    "sync"
    "time"

    "github.com/ethereum/go-ethereum/pow"
    "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/rlp"
)

// This is the target maximum size of returned blocks for the
// getBlocks message. The reply message may exceed it
// if a single block is larger than the limit.
const maxBlockRespSize = 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 {
    protVer, netId int
    txpool         txPool
    chainman       *core.ChainManager
    downloader     *downloader.Downloader
    fetcher        *fetcher.Fetcher
    peers          *peerSet

    SubProtocol 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(protocolVersion, networkId int, mux *event.TypeMux, txpool txPool, pow pow.PoW, chainman *core.ChainManager) *ProtocolManager {
    // Create the protocol manager and initialize peer handlers
    manager := &ProtocolManager{
        eventMux:  mux,
        txpool:    txpool,
        chainman:  chainman,
        peers:     newPeerSet(),
        newPeerCh: make(chan *peer, 1),
        txsyncCh:  make(chan *txsync),
        quitSync:  make(chan struct{}),
    }
    manager.SubProtocol = p2p.Protocol{
        Name:    "eth",
        Version: uint(protocolVersion),
        Length:  ProtocolLength,
        Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
            peer := manager.newPeer(protocolVersion, 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.InsertChain, manager.removePeer)

    validator := func(block *types.Block, parent *types.Block) error {
        return core.ValidateHeader(pow, block.Header(), parent.Header(), true)
    }
    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 {
    td, current, genesis := pm.chainman.Status()

    return newPeer(pv, nv, genesis, current, td, p, rw)
}

func (pm *ProtocolManager) handle(p *peer) error {
    // Execute the Ethereum handshake.
    if err := p.handleStatus(); err != nil {
        return err
    }

    // Register the peer locally.
    glog.V(logger.Detail).Infoln("Adding peer", p.id)
    if err := pm.peers.Register(p); err != nil {
        glog.V(logger.Error).Infoln("Addition failed:", 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.Head(), p.requestHashes, p.requestBlocks); 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 {
            return err
        }
    }
    return nil
}

func (pm *ProtocolManager) handleMsg(p *peer) error {
    msg, err := p.rw.ReadMsg()
    if err != nil {
        return err
    }
    if msg.Size > ProtocolMaxMsgSize {
        return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
    }
    // make sure that the payload has been fully consumed
    defer msg.Discard()

    switch msg.Code {
    case StatusMsg:
        return errResp(ErrExtraStatusMsg, "uncontrolled status message")

    case TxMsg:
        // TODO: rework using lazy RLP stream
        var txs []*types.Transaction
        if err := msg.Decode(&txs); err != nil {
            return errResp(ErrDecode, "msg %v: %v", msg, err)
        }
        for i, tx := range txs {
            if tx == nil {
                return errResp(ErrDecode, "transaction %d is nil", i)
            }
            jsonlogger.LogJson(&logger.EthTxReceived{
                TxHash:   tx.Hash().Hex(),
                RemoteId: p.ID().String(),
            })
        }
        pm.txpool.AddTransactions(txs)

    case GetBlockHashesMsg:
        var request getBlockHashesMsgData
        if err := msg.Decode(&request); err != nil {
            return errResp(ErrDecode, "->msg %v: %v", msg, err)
        }

        if request.Amount > uint64(downloader.MaxHashFetch) {
            request.Amount = uint64(downloader.MaxHashFetch)
        }

        hashes := pm.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)

        if glog.V(logger.Debug) {
            if len(hashes) == 0 {
                glog.Infof("invalid block hash %x", request.Hash.Bytes()[:4])
            }
        }

        // returns either requested hashes or nothing (i.e. not found)
        return p.sendBlockHashes(hashes)

    case BlockHashesMsg:
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))

        var hashes []common.Hash
        if err := msgStream.Decode(&hashes); err != nil {
            break
        }
        err := pm.downloader.DeliverHashes(p.id, hashes)
        if err != nil {
            glog.V(logger.Debug).Infoln(err)
        }

    case 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
            hashes []common.Hash
            blocks []*types.Block
        )
        for {
            err := msgStream.Decode(&hash)
            if err == rlp.EOL {
                break
            } else if err != nil {
                return errResp(ErrDecode, "msg %v: %v", msg, err)
            }
            hashes = append(hashes, hash)

            // Retrieve the requested block, stopping if enough was found
            if block := pm.chainman.GetBlock(hash); block != nil {
                blocks = append(blocks, block)
                bytes += block.Size()
                if len(blocks) >= downloader.MaxBlockFetch || bytes > maxBlockRespSize {
                    break
                }
            }
        }
        if glog.V(logger.Detail) && len(blocks) == 0 && len(hashes) > 0 {
            list := "["
            for _, hash := range hashes {
                list += fmt.Sprintf("%x, ", hash[:4])
            }
            list = list[:len(list)-2] + "]"

            glog.Infof("Peer %s: no blocks found for requested hashes %s", p.id, list)
        }
        return p.sendBlocks(blocks)

    case BlocksMsg:
        // Decode the arrived block message
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))

        var blocks []*types.Block
        if err := msgStream.Decode(&blocks); err != nil {
            glog.V(logger.Detail).Infoln("Decode error", err)
            blocks = nil
        }
        // Update the receive timestamp of each block
        for i:=0; i<len(blocks); i++ {
            blocks[i].ReceivedAt = msg.ReceivedAt
        }
        // Filter out any explicitly requested blocks, deliver the rest to the downloader
        if blocks := pm.fetcher.Filter(blocks); len(blocks) > 0 {
            pm.downloader.DeliverBlocks(p.id, blocks)
        }

    case NewBlockHashesMsg:
        // Retrieve and deseralize the remote new block hashes notification
        msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))

        var hashes []common.Hash
        if err := msgStream.Decode(&hashes); err != nil {
            break
        }
        // Mark the hashes as present at the remote node
        for _, hash := range hashes {
            p.blockHashes.Add(hash)
            p.SetHead(hash)
        }
        // Schedule all the unknown hashes for retrieval
        unknown := make([]common.Hash, 0, len(hashes))
        for _, hash := range hashes {
            if !pm.chainman.HasBlock(hash) {
                unknown = append(unknown, hash)
            }
        }
        for _, hash := range unknown {
            pm.fetcher.Notify(p.id, hash, time.Now(), p.requestBlocks)
        }

    case NewBlockMsg:
        // Retrieve and decode the propagated block
        var request newBlockMsgData
        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.blockHashes.Add(request.Block.Hash())
        p.SetHead(request.Block.Hash())

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

        // TODO: Schedule a sync to cover potential gaps (this needs proto update)
        p.SetTd(request.TD)
        go pm.synchronise(p)

    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 {
        transfer := peers[:int(math.Sqrt(float64(len(peers))))]
        for _, peer := range transfer {
            peer.sendNewBlock(block)
        }
        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 {
            peer.sendNewBlockHashes([]common.Hash{hash})
        }
        glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), time.Since(block.ReceivedAt))
    }
}

// BroadcastTx will propagate the block to its connected peers. It will sort
// out which peers do not contain the block in their block set and will do a
// sqrt(peers) to determine the amount of peers we broadcast to.
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.sendTransaction(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, false)
            self.BroadcastBlock(ev.Block, true)
        }
    }
}

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)
    }
}