whisper: bloom filter refactoring (ethereum#16046)

* whisper: bloom filter refactoring

* whisper: fixed full node

whisper/whisperv6/peer.go

@@ -36,7 +36,8 @@ type Peer struct {
 
 	trusted        bool
 	powRequirement float64
-	bloomFilter    []byte // may contain nil in case of full node
+	bloomFilter    []byte
+	fullNode       bool
 
 	known *set.Set // Messages already known by the peer to avoid wasting bandwidth
 
@@ -53,6 +54,8 @@ func newPeer(host *Whisper, remote *p2p.Peer, rw p2p.MsgReadWriter) *Peer {
 		powRequirement: 0.0,
 		known:          set.New(),
 		quit:           make(chan struct{}),
+		bloomFilter:    makeFullNodeBloom(),
+		fullNode:       true,
 	}
 }
 
@@ -118,11 +121,7 @@ func (peer *Peer) handshake() error {
 			if sz != bloomFilterSize && sz != 0 {
 				return fmt.Errorf("peer [%x] sent bad status message: wrong bloom filter size %d", peer.ID(), sz)
 			}
-			if isFullNode(bloom) {
-				peer.bloomFilter = nil
-			} else {
-				peer.bloomFilter = bloom
-			}
+			peer.setBloomFilter(bloom)
 		}
 	}
 
@@ -226,10 +225,21 @@ func (peer *Peer) notifyAboutBloomFilterChange(bloom []byte) error {
 }
 
 func (peer *Peer) bloomMatch(env *Envelope) bool {
-	if peer.bloomFilter == nil {
-		// no filter - full node, accepts all envelops
-		return true
+	return peer.fullNode || bloomFilterMatch(peer.bloomFilter, env.Bloom())
+}
+
+func (peer *Peer) setBloomFilter(bloom []byte) {
+	peer.bloomFilter = bloom
+	peer.fullNode = isFullNode(bloom)
+	if peer.fullNode && peer.bloomFilter == nil {
+		peer.bloomFilter = makeFullNodeBloom()
 	}
+}
 
-	return bloomFilterMatch(peer.bloomFilter, env.Bloom())
+func makeFullNodeBloom() []byte {
+	bloom := make([]byte, bloomFilterSize)
+	for i := 0; i < bloomFilterSize; i++ {
+		bloom[i] = 0xFF
+	}
+	return bloom
 }

whisper/whisperv6/whisper.go

@@ -710,11 +710,7 @@ func (whisper *Whisper) runMessageLoop(p *Peer, rw p2p.MsgReadWriter) error {
 				log.Warn("failed to decode bloom filter exchange message, peer will be disconnected", "peer", p.peer.ID(), "err", err)
 				return errors.New("invalid bloom filter exchange message")
 			}
-			if isFullNode(bloom) {
-				p.bloomFilter = nil
-			} else {
-				p.bloomFilter = bloom
-			}
+			p.setBloomFilter(bloom)
 		case p2pMessageCode:
 			// peer-to-peer message, sent directly to peer bypassing PoW checks, etc.
 			// this message is not supposed to be forwarded to other peers, and
@@ -1049,7 +1045,6 @@ func isFullNode(bloom []byte) bool {
 
 func bloomFilterMatch(filter, sample []byte) bool {
 	if filter == nil {
-		// full node, accepts all messages
 		return true
 	}