github.com/bcskill/bcschain/v3@v3.4.9-beta2/whisper/whisperv6/peer.go (about) 1 // Copyright 2016 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package whisperv6 18 19 import ( 20 "context" 21 "fmt" 22 "math" 23 "time" 24 25 "go.opencensus.io/trace" 26 27 "sync" 28 29 "github.com/bcskill/bcschain/v3/common" 30 "github.com/bcskill/bcschain/v3/log" 31 "github.com/bcskill/bcschain/v3/p2p" 32 "github.com/bcskill/bcschain/v3/rlp" 33 ) 34 35 // Peer represents a whisper protocol peer connection. 36 type Peer struct { 37 host *Whisper 38 peer *p2p.Peer 39 ws p2p.MsgReadWriter 40 41 mu sync.RWMutex 42 trusted bool 43 powRequirement float64 44 bloomFilter []byte 45 fullNode bool 46 47 knownMu sync.RWMutex 48 known map[common.Hash]struct{} // Messages already known by the peer to avoid wasting bandwidth 49 50 quit chan struct{} 51 } 52 53 // newPeer creates a new whisper peer object, but does not run the handshake itself. 54 func newPeer(host *Whisper, remote *p2p.Peer, rw p2p.MsgReadWriter) *Peer { 55 return &Peer{ 56 host: host, 57 peer: remote, 58 ws: rw, 59 trusted: false, 60 powRequirement: 0.0, 61 known: make(map[common.Hash]struct{}), 62 quit: make(chan struct{}), 63 bloomFilter: makeFullNodeBloom(), 64 fullNode: true, 65 } 66 } 67 68 // start initiates the peer updater, periodically broadcasting the whisper packets 69 // into the network. 70 func (peer *Peer) start() { 71 go peer.update() 72 log.Trace("start", "peer", peer.ID()) 73 } 74 75 // stop terminates the peer updater, stopping message forwarding to it. 76 func (peer *Peer) stop() { 77 close(peer.quit) 78 log.Trace("stop", "peer", peer.ID()) 79 } 80 81 // handshake sends the protocol initiation status message to the remote peer and 82 // verifies the remote status too. 83 func (peer *Peer) handshake() error { 84 // Send the handshake status message asynchronously 85 errc := make(chan error, 1) 86 go func() { 87 pow := peer.host.MinPow() 88 powConverted := math.Float64bits(pow) 89 bloom := peer.host.BloomFilter() 90 errc <- p2p.SendItems(peer.ws, statusCode, ProtocolVersion, powConverted, bloom) 91 }() 92 93 // Fetch the remote status packet and verify protocol match 94 packet, err := peer.ws.ReadMsg() 95 if err != nil { 96 return err 97 } 98 if packet.Code != statusCode { 99 return fmt.Errorf("peer [%x] sent packet %x before status packet", peer.ID(), packet.Code) 100 } 101 s := rlp.NewStream(packet.Payload, uint64(packet.Size)) 102 defer rlp.Discard(s) 103 _, err = s.List() 104 if err != nil { 105 return fmt.Errorf("peer [%x] sent bad status message: %v", peer.ID(), err) 106 } 107 peerVersion, err := s.Uint() 108 if err != nil { 109 return fmt.Errorf("peer [%x] sent bad status message (unable to decode version): %v", peer.ID(), err) 110 } 111 if peerVersion != ProtocolVersion { 112 return fmt.Errorf("peer [%x]: protocol version mismatch %d != %d", peer.ID(), peerVersion, ProtocolVersion) 113 } 114 115 // only version is mandatory, subsequent parameters are optional 116 powRaw, err := s.Uint() 117 if err == nil { 118 pow := math.Float64frombits(powRaw) 119 if math.IsInf(pow, 0) || math.IsNaN(pow) || pow < 0.0 { 120 return fmt.Errorf("peer [%x] sent bad status message: invalid pow", peer.ID()) 121 } 122 peer.mu.Lock() 123 peer.powRequirement = pow 124 peer.mu.Unlock() 125 126 var bloom []byte 127 err = s.Decode(&bloom) 128 if err == nil { 129 sz := len(bloom) 130 if sz != bloomFilterSize && sz != 0 { 131 return fmt.Errorf("peer [%x] sent bad status message: wrong bloom filter size %d", peer.ID(), sz) 132 } 133 peer.setBloomFilter(bloom) 134 } 135 } 136 137 if err := <-errc; err != nil { 138 return fmt.Errorf("peer [%x] failed to send status packet: %v", peer.ID(), err) 139 } 140 return nil 141 } 142 143 // update executes periodic operations on the peer, including message transmission 144 // and expiration. 145 func (peer *Peer) update() { 146 // Start the tickers for the updates 147 expire := time.NewTicker(expirationCycle) 148 transmit := time.NewTicker(transmissionCycle) 149 150 // Loop and transmit until termination is requested 151 for { 152 select { 153 case <-expire.C: 154 peer.expire() 155 156 case <-transmit.C: 157 ctx, span := trace.StartSpan(context.Background(), "Peer.update.transmit") 158 if err := peer.broadcast(ctx); err != nil { 159 log.Trace("broadcast failed", "reason", err, "peer", peer.ID()) 160 span.SetStatus(trace.Status{ 161 Code: trace.StatusCodeInternal, 162 Message: err.Error(), 163 }) 164 span.End() 165 return 166 } 167 span.End() 168 169 case <-peer.quit: 170 return 171 } 172 } 173 } 174 175 // mark marks an envelope known to the peer so that it won't be sent back. 176 func (peer *Peer) mark(envelope *Envelope) { 177 h := envelope.Hash() 178 peer.knownMu.Lock() 179 peer.known[h] = struct{}{} 180 peer.knownMu.Unlock() 181 } 182 183 // marked checks if an envelope is already known to the remote peer. 184 func (peer *Peer) marked(envelope *Envelope) bool { 185 h := envelope.Hash() 186 peer.knownMu.RLock() 187 _, ok := peer.known[h] 188 peer.knownMu.RUnlock() 189 return ok 190 } 191 192 // expire iterates over all the known envelopes in the host and removes all 193 // expired (unknown) ones from the known list. 194 func (peer *Peer) expire() { 195 unmark := make(map[common.Hash]struct{}) 196 peer.knownMu.Lock() 197 defer peer.knownMu.Unlock() 198 for h := range peer.known { 199 if !peer.host.isEnvelopeCached(h) { 200 unmark[h] = struct{}{} 201 } 202 } 203 // Dump all known but no longer cached 204 for hash := range unmark { 205 delete(peer.known, hash) 206 } 207 } 208 209 // broadcast iterates over the collection of envelopes and transmits yet unknown 210 // ones over the network. 211 func (peer *Peer) broadcast(ctx context.Context) error { 212 envelopes := peer.host.Envelopes() 213 bundle := make([]*Envelope, 0, len(envelopes)) 214 for _, envelope := range envelopes { 215 peer.mu.RLock() 216 pow := peer.powRequirement 217 peer.mu.RUnlock() 218 if !peer.marked(envelope) && envelope.PoW() >= pow && peer.bloomMatch(envelope) { 219 bundle = append(bundle, envelope) 220 } 221 } 222 223 if len(bundle) > 0 { 224 // transmit the batch of envelopes 225 if err := p2p.Send(peer.ws, messagesCode, bundle); err != nil { 226 return err 227 } 228 229 // mark envelopes only if they were successfully sent 230 for _, e := range bundle { 231 peer.mark(e) 232 } 233 234 log.Trace("broadcast", "num. messages", len(bundle)) 235 } 236 return nil 237 } 238 239 // ID returns a peer's id 240 func (peer *Peer) ID() []byte { 241 id := peer.peer.ID() 242 return id[:] 243 } 244 245 func (peer *Peer) notifyAboutPowRequirementChange(ctx context.Context, pow float64) error { 246 i := math.Float64bits(pow) 247 return p2p.Send(peer.ws, powRequirementCode, i) 248 } 249 250 func (peer *Peer) notifyAboutBloomFilterChange(ctx context.Context, bloom []byte) error { 251 return p2p.Send(peer.ws, bloomFilterExCode, bloom) 252 } 253 254 func (peer *Peer) bloomMatch(env *Envelope) bool { 255 peer.mu.RLock() 256 bf := peer.bloomFilter 257 peer.mu.RUnlock() 258 return peer.fullNode || bloomFilterMatch(bf, env.Bloom()) 259 } 260 261 func (peer *Peer) setBloomFilter(bloom []byte) { 262 peer.mu.Lock() 263 defer peer.mu.Unlock() 264 peer.bloomFilter = bloom 265 peer.fullNode = isFullNode(bloom) 266 if peer.fullNode && peer.bloomFilter == nil { 267 peer.bloomFilter = makeFullNodeBloom() 268 } 269 } 270 271 func makeFullNodeBloom() []byte { 272 bloom := make([]byte, bloomFilterSize) 273 for i := 0; i < bloomFilterSize; i++ { 274 bloom[i] = 0xFF 275 } 276 return bloom 277 }