diff --git a/core/blockchain_reader.go b/core/blockchain_reader.go index 66e66a09427e..c9054bec41d6 100644 --- a/core/blockchain_reader.go +++ b/core/blockchain_reader.go @@ -73,6 +73,12 @@ func (bc *BlockChain) GetHeaderByNumber(number uint64) *types.Header { return bc.hc.GetHeaderByNumber(number) } +// GetHeadersFrom returns a contiguous segment of headers, in rlp-form, going +// backwards from the given number. +func (bc *BlockChain) GetHeadersFrom(number, count uint64) []rlp.RawValue { + return bc.hc.GetHeadersFrom(number, count) +} + // GetBody retrieves a block body (transactions and uncles) from the database by // hash, caching it if found. func (bc *BlockChain) GetBody(hash common.Hash) *types.Body { diff --git a/core/headerchain.go b/core/headerchain.go index 93704a062420..1137b237f7e6 100644 --- a/core/headerchain.go +++ b/core/headerchain.go @@ -33,6 +33,7 @@ import ( "github.com/Kapoio/go-kapoio/ethdb" "github.com/Kapoio/go-kapoio/log" "github.com/Kapoio/go-kapoio/params" + "github.com/Kapoio/go-kapoio/rlp" lru "github.com/hashicorp/golang-lru" ) @@ -498,6 +499,46 @@ func (hc *HeaderChain) GetHeaderByNumber(number uint64) *types.Header { return hc.GetHeader(hash, number) } +// GetHeadersFrom returns a contiguous segment of headers, in rlp-form, going +// backwards from the given number. +// If the 'number' is higher than the highest local header, this method will +// return a best-effort response, containing the headers that we do have. +func (hc *HeaderChain) GetHeadersFrom(number, count uint64) []rlp.RawValue { + // If the request is for future headers, we still return the portion of + // headers that we are able to serve + if current := hc.CurrentHeader().Number.Uint64(); current < number { + if count > number-current { + count -= number - current + number = current + } else { + return nil + } + } + var headers []rlp.RawValue + // If we have some of the headers in cache already, use that before going to db. + hash := rawdb.ReadCanonicalHash(hc.chainDb, number) + if hash == (common.Hash{}) { + return nil + } + for count > 0 { + header, ok := hc.headerCache.Get(hash) + if !ok { + break + } + h := header.(*types.Header) + rlpData, _ := rlp.EncodeToBytes(h) + headers = append(headers, rlpData) + hash = h.ParentHash + count-- + number-- + } + // Read remaining from db + if count > 0 { + headers = append(headers, rawdb.ReadHeaderRange(hc.chainDb, number, count)...) + } + return headers +} + func (hc *HeaderChain) GetCanonicalHash(number uint64) common.Hash { return rawdb.ReadCanonicalHash(hc.chainDb, number) } diff --git a/core/rawdb/accessors_chain.go b/core/rawdb/accessors_chain.go index 0ef62ae7d93e..fb329936be8a 100644 --- a/core/rawdb/accessors_chain.go +++ b/core/rawdb/accessors_chain.go @@ -279,6 +279,56 @@ func WriteFastTxLookupLimit(db ethdb.KeyValueWriter, number uint64) { } } +// ReadHeaderRange returns the rlp-encoded headers, starting at 'number', and going +// backwards towards genesis. This method assumes that the caller already has +// placed a cap on count, to prevent DoS issues. +// Since this method operates in head-towards-genesis mode, it will return an empty +// slice in case the head ('number') is missing. Hence, the caller must ensure that +// the head ('number') argument is actually an existing header. +// +// N.B: Since the input is a number, as opposed to a hash, it's implicit that +// this method only operates on canon headers. +func ReadHeaderRange(db ethdb.Reader, number uint64, count uint64) []rlp.RawValue { + var rlpHeaders []rlp.RawValue + if count == 0 { + return rlpHeaders + } + i := number + if count-1 > number { + // It's ok to request block 0, 1 item + count = number + 1 + } + limit, _ := db.Ancients() + // First read live blocks + if i >= limit { + // If we need to read live blocks, we need to figure out the hash first + hash := ReadCanonicalHash(db, number) + for ; i >= limit && count > 0; i-- { + if data, _ := db.Get(headerKey(i, hash)); len(data) > 0 { + rlpHeaders = append(rlpHeaders, data) + // Get the parent hash for next query + hash = types.HeaderParentHashFromRLP(data) + } else { + break // Maybe got moved to ancients + } + count-- + } + } + if count == 0 { + return rlpHeaders + } + // read remaining from ancients + max := count * 700 + data, err := db.AncientRange(freezerHeaderTable, i+1-count, count, max) + if err == nil && uint64(len(data)) == count { + // the data is on the order [h, h+1, .., n] -- reordering needed + for i := range data { + rlpHeaders = append(rlpHeaders, data[len(data)-1-i]) + } + } + return rlpHeaders +} + // ReadHeaderRLP retrieves a block header in its raw RLP database encoding. func ReadHeaderRLP(db ethdb.Reader, hash common.Hash, number uint64) rlp.RawValue { var data []byte diff --git a/core/rawdb/accessors_chain_test.go b/core/rawdb/accessors_chain_test.go index 06d569c04f00..9419085f8ae6 100644 --- a/core/rawdb/accessors_chain_test.go +++ b/core/rawdb/accessors_chain_test.go @@ -883,3 +883,67 @@ func BenchmarkDecodeRLPLogs(b *testing.B) { } }) } + +func TestHeadersRLPStorage(t *testing.T) { + // Have N headers in the freezer + frdir, err := ioutil.TempDir("", "") + if err != nil { + t.Fatalf("failed to create temp freezer dir: %v", err) + } + defer os.Remove(frdir) + + db, err := NewDatabaseWithFreezer(NewMemoryDatabase(), frdir, "", false) + if err != nil { + t.Fatalf("failed to create database with ancient backend") + } + defer db.Close() + // Create blocks + var chain []*types.Block + var pHash common.Hash + for i := 0; i < 100; i++ { + block := types.NewBlockWithHeader(&types.Header{ + Number: big.NewInt(int64(i)), + Extra: []byte("test block"), + UncleHash: types.EmptyUncleHash, + TxHash: types.EmptyRootHash, + ReceiptHash: types.EmptyRootHash, + ParentHash: pHash, + }) + chain = append(chain, block) + pHash = block.Hash() + } + var receipts []types.Receipts = make([]types.Receipts, 100) + // Write first half to ancients + WriteAncientBlocks(db, chain[:50], receipts[:50], big.NewInt(100)) + // Write second half to db + for i := 50; i < 100; i++ { + WriteCanonicalHash(db, chain[i].Hash(), chain[i].NumberU64()) + WriteBlock(db, chain[i]) + } + checkSequence := func(from, amount int) { + headersRlp := ReadHeaderRange(db, uint64(from), uint64(amount)) + if have, want := len(headersRlp), amount; have != want { + t.Fatalf("have %d headers, want %d", have, want) + } + for i, headerRlp := range headersRlp { + var header types.Header + if err := rlp.DecodeBytes(headerRlp, &header); err != nil { + t.Fatal(err) + } + if have, want := header.Number.Uint64(), uint64(from-i); have != want { + t.Fatalf("wrong number, have %d want %d", have, want) + } + } + } + checkSequence(99, 20) // Latest block and 19 parents + checkSequence(99, 50) // Latest block -> all db blocks + checkSequence(99, 51) // Latest block -> one from ancients + checkSequence(99, 52) // Latest blocks -> two from ancients + checkSequence(50, 2) // One from db, one from ancients + checkSequence(49, 1) // One from ancients + checkSequence(49, 50) // All ancient ones + checkSequence(99, 100) // All blocks + checkSequence(0, 1) // Only genesis + checkSequence(1, 1) // Only block 1 + checkSequence(1, 2) // Genesis + block 1 +} diff --git a/core/types/block.go b/core/types/block.go index 63b69aa5abe8..f65405f0def3 100644 --- a/core/types/block.go +++ b/core/types/block.go @@ -389,3 +389,21 @@ func (b *Block) Hash() common.Hash { } type Blocks []*Block + +// HeaderParentHashFromRLP returns the parentHash of an RLP-encoded +// header. If 'header' is invalid, the zero hash is returned. +func HeaderParentHashFromRLP(header []byte) common.Hash { + // parentHash is the first list element. + listContent, _, err := rlp.SplitList(header) + if err != nil { + return common.Hash{} + } + parentHash, _, err := rlp.SplitString(listContent) + if err != nil { + return common.Hash{} + } + if len(parentHash) != 32 { + return common.Hash{} + } + return common.BytesToHash(parentHash) +} diff --git a/core/types/block_test.go b/core/types/block_test.go index 5809fb2e0522..f72bc5eb48e1 100644 --- a/core/types/block_test.go +++ b/core/types/block_test.go @@ -281,3 +281,64 @@ func makeBenchBlock() *Block { } return NewBlock(header, txs, uncles, receipts, newHasher()) } + +func TestRlpDecodeParentHash(t *testing.T) { + // A minimum one + want := common.HexToHash("0x112233445566778899001122334455667788990011223344556677889900aabb") + if rlpData, err := rlp.EncodeToBytes(Header{ParentHash: want}); err != nil { + t.Fatal(err) + } else { + if have := HeaderParentHashFromRLP(rlpData); have != want { + t.Fatalf("have %x, want %x", have, want) + } + } + // And a maximum one + // | Difficulty | dynamic| *big.Int | 0x5ad3c2c71bbff854908 (current mainnet TD: 76 bits) | + // | Number | dynamic| *big.Int | 64 bits | + // | Extra | dynamic| []byte | 65+32 byte (clique) | + // | BaseFee | dynamic| *big.Int | 64 bits | + mainnetTd := new(big.Int) + mainnetTd.SetString("5ad3c2c71bbff854908", 16) + if rlpData, err := rlp.EncodeToBytes(Header{ + ParentHash: want, + Difficulty: mainnetTd, + Number: new(big.Int).SetUint64(math.MaxUint64), + Extra: make([]byte, 65+32), + BaseFee: new(big.Int).SetUint64(math.MaxUint64), + }); err != nil { + t.Fatal(err) + } else { + if have := HeaderParentHashFromRLP(rlpData); have != want { + t.Fatalf("have %x, want %x", have, want) + } + } + // Also test a very very large header. + { + // The rlp-encoding of the heder belowCauses _total_ length of 65540, + // which is the first to blow the fast-path. + h := Header{ + ParentHash: want, + Extra: make([]byte, 65041), + } + if rlpData, err := rlp.EncodeToBytes(h); err != nil { + t.Fatal(err) + } else { + if have := HeaderParentHashFromRLP(rlpData); have != want { + t.Fatalf("have %x, want %x", have, want) + } + } + } + { + // Test some invalid erroneous stuff + for i, rlpData := range [][]byte{ + nil, + common.FromHex("0x"), + common.FromHex("0x01"), + common.FromHex("0x3031323334"), + } { + if have, want := HeaderParentHashFromRLP(rlpData), (common.Hash{}); have != want { + t.Fatalf("invalid %d: have %x, want %x", i, have, want) + } + } + } +} diff --git a/eth/downloader/downloader_test.go b/eth/downloader/downloader_test.go index 9da3594a0efe..152066aa8307 100644 --- a/eth/downloader/downloader_test.go +++ b/eth/downloader/downloader_test.go @@ -154,12 +154,24 @@ func (dlp *downloadTesterPeer) Head() (common.Hash, *big.Int) { return head.Hash(), dlp.chain.GetTd(head.Hash(), head.NumberU64()) } +func unmarshalRlpHeaders(rlpdata []rlp.RawValue) []*types.Header { + var headers = make([]*types.Header, len(rlpdata)) + for i, data := range rlpdata { + var h types.Header + if err := rlp.DecodeBytes(data, &h); err != nil { + panic(err) + } + headers[i] = &h + } + return headers +} + // RequestHeadersByHash constructs a GetBlockHeaders function based on a hashed // origin; associated with a particular peer in the download tester. The returned // function can be used to retrieve batches of headers from the particular peer. func (dlp *downloadTesterPeer) RequestHeadersByHash(origin common.Hash, amount int, skip int, reverse bool, sink chan *eth.Response) (*eth.Request, error) { // Service the header query via the live handler code - headers := eth.ServiceGetBlockHeadersQuery(dlp.chain, ð.GetBlockHeadersPacket{ + rlpHeaders := eth.ServiceGetBlockHeadersQuery(dlp.chain, ð.GetBlockHeadersPacket{ Origin: eth.HashOrNumber{ Hash: origin, }, @@ -167,7 +179,7 @@ func (dlp *downloadTesterPeer) RequestHeadersByHash(origin common.Hash, amount i Skip: uint64(skip), Reverse: reverse, }, nil) - + headers := unmarshalRlpHeaders(rlpHeaders) // If a malicious peer is simulated withholding headers, delete them for hash := range dlp.withholdHeaders { for i, header := range headers { @@ -203,7 +215,7 @@ func (dlp *downloadTesterPeer) RequestHeadersByHash(origin common.Hash, amount i // function can be used to retrieve batches of headers from the particular peer. func (dlp *downloadTesterPeer) RequestHeadersByNumber(origin uint64, amount int, skip int, reverse bool, sink chan *eth.Response) (*eth.Request, error) { // Service the header query via the live handler code - headers := eth.ServiceGetBlockHeadersQuery(dlp.chain, ð.GetBlockHeadersPacket{ + rlpHeaders := eth.ServiceGetBlockHeadersQuery(dlp.chain, ð.GetBlockHeadersPacket{ Origin: eth.HashOrNumber{ Number: origin, }, @@ -211,7 +223,7 @@ func (dlp *downloadTesterPeer) RequestHeadersByNumber(origin uint64, amount int, Skip: uint64(skip), Reverse: reverse, }, nil) - + headers := unmarshalRlpHeaders(rlpHeaders) // If a malicious peer is simulated withholding headers, delete them for hash := range dlp.withholdHeaders { for i, header := range headers { diff --git a/eth/handler_eth_test.go b/eth/handler_eth_test.go index 7ba680df6a71..b6f0455f5cb9 100644 --- a/eth/handler_eth_test.go +++ b/eth/handler_eth_test.go @@ -38,6 +38,7 @@ import ( "github.com/Kapoio/go-kapoio/p2p" "github.com/Kapoio/go-kapoio/p2p/enode" "github.com/Kapoio/go-kapoio/params" + "github.com/Kapoio/go-kapoio/rlp" ) // testEthHandler is a mock event handler to listen for inbound network requests @@ -560,15 +561,17 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo // Create a block to reply to the challenge if no timeout is simulated. if !timeout { if empty { - if err := remote.ReplyBlockHeaders(request.RequestId, []*types.Header{}); err != nil { + if err := remote.ReplyBlockHeadersRLP(request.RequestId, []rlp.RawValue{}); err != nil { t.Fatalf("failed to answer challenge: %v", err) } } else if match { - if err := remote.ReplyBlockHeaders(request.RequestId, []*types.Header{response}); err != nil { + responseRlp, _ := rlp.EncodeToBytes(response) + if err := remote.ReplyBlockHeadersRLP(request.RequestId, []rlp.RawValue{responseRlp}); err != nil { t.Fatalf("failed to answer challenge: %v", err) } } else { - if err := remote.ReplyBlockHeaders(request.RequestId, []*types.Header{{Number: response.Number}}); err != nil { + responseRlp, _ := rlp.EncodeToBytes(types.Header{Number: response.Number}) + if err := remote.ReplyBlockHeadersRLP(request.RequestId, []rlp.RawValue{responseRlp}); err != nil { t.Fatalf("failed to answer challenge: %v", err) } } diff --git a/eth/protocols/eth/handler.go b/eth/protocols/eth/handler.go index a9e71cf32279..e20dfbb04bae 100644 --- a/eth/protocols/eth/handler.go +++ b/eth/protocols/eth/handler.go @@ -35,9 +35,6 @@ const ( // softResponseLimit is the target maximum size of replies to data retrievals. softResponseLimit = 2 * 1024 * 1024 - // estHeaderSize is the approximate size of an RLP encoded block header. - estHeaderSize = 500 - // maxHeadersServe is the maximum number of block headers to serve. This number // is there to limit the number of disk lookups. maxHeadersServe = 1024 diff --git a/eth/protocols/eth/handler_test.go b/eth/protocols/eth/handler_test.go index 1b6df99a3837..3418cb9af8ff 100644 --- a/eth/protocols/eth/handler_test.go +++ b/eth/protocols/eth/handler_test.go @@ -136,11 +136,13 @@ func testGetBlockHeaders(t *testing.T, protocol uint) { query *GetBlockHeadersPacket // The query to execute for header retrieval expect []common.Hash // The hashes of the block whose headers are expected }{ - // A single random block should be retrievable by hash and number too + // A single random block should be retrievable by hash { &GetBlockHeadersPacket{Origin: HashOrNumber{Hash: backend.chain.GetBlockByNumber(limit / 2).Hash()}, Amount: 1}, []common.Hash{backend.chain.GetBlockByNumber(limit / 2).Hash()}, - }, { + }, + // A single random block should be retrievable by number + { &GetBlockHeadersPacket{Origin: HashOrNumber{Number: limit / 2}, Amount: 1}, []common.Hash{backend.chain.GetBlockByNumber(limit / 2).Hash()}, }, @@ -180,10 +182,15 @@ func testGetBlockHeaders(t *testing.T, protocol uint) { { &GetBlockHeadersPacket{Origin: HashOrNumber{Number: 0}, Amount: 1}, []common.Hash{backend.chain.GetBlockByNumber(0).Hash()}, - }, { + }, + { &GetBlockHeadersPacket{Origin: HashOrNumber{Number: backend.chain.CurrentBlock().NumberU64()}, Amount: 1}, []common.Hash{backend.chain.CurrentBlock().Hash()}, }, + { // If the peer requests a bit into the future, we deliver what we have + &GetBlockHeadersPacket{Origin: HashOrNumber{Number: backend.chain.CurrentBlock().NumberU64()}, Amount: 10}, + []common.Hash{backend.chain.CurrentBlock().Hash()}, + }, // Ensure protocol limits are honored { &GetBlockHeadersPacket{Origin: HashOrNumber{Number: backend.chain.CurrentBlock().NumberU64() - 1}, Amount: limit + 10, Reverse: true}, @@ -280,7 +287,7 @@ func testGetBlockHeaders(t *testing.T, protocol uint) { RequestId: 456, BlockHeadersPacket: headers, }); err != nil { - t.Errorf("test %d: headers mismatch: %v", i, err) + t.Errorf("test %d by hash: headers mismatch: %v", i, err) } } } diff --git a/eth/protocols/eth/handlers.go b/eth/protocols/eth/handlers.go index adfb4b5809a9..00392015facc 100644 --- a/eth/protocols/eth/handlers.go +++ b/eth/protocols/eth/handlers.go @@ -36,12 +36,21 @@ func handleGetBlockHeaders66(backend Backend, msg Decoder, peer *Peer) error { return fmt.Errorf("%w: message %v: %v", errDecode, msg, err) } response := ServiceGetBlockHeadersQuery(backend.Chain(), query.GetBlockHeadersPacket, peer) - return peer.ReplyBlockHeaders(query.RequestId, response) + return peer.ReplyBlockHeadersRLP(query.RequestId, response) } // ServiceGetBlockHeadersQuery assembles the response to a header query. It is // exposed to allow external packages to test protocol behavior. -func ServiceGetBlockHeadersQuery(chain *core.BlockChain, query *GetBlockHeadersPacket, peer *Peer) []*types.Header { +func ServiceGetBlockHeadersQuery(chain *core.BlockChain, query *GetBlockHeadersPacket, peer *Peer) []rlp.RawValue { + if query.Skip == 0 { + // The fast path: when the request is for a contiguous segment of headers. + return serviceContiguousBlockHeaderQuery(chain, query) + } else { + return serviceNonContiguousBlockHeaderQuery(chain, query, peer) + } +} + +func serviceNonContiguousBlockHeaderQuery(chain *core.BlockChain, query *GetBlockHeadersPacket, peer *Peer) []rlp.RawValue { hashMode := query.Origin.Hash != (common.Hash{}) first := true maxNonCanonical := uint64(100) @@ -49,7 +58,7 @@ func ServiceGetBlockHeadersQuery(chain *core.BlockChain, query *GetBlockHeadersP // Gather headers until the fetch or network limits is reached var ( bytes common.StorageSize - headers []*types.Header + headers []rlp.RawValue unknown bool lookups int ) @@ -74,9 +83,12 @@ func ServiceGetBlockHeadersQuery(chain *core.BlockChain, query *GetBlockHeadersP if origin == nil { break } - headers = append(headers, origin) - bytes += estHeaderSize - + if rlpData, err := rlp.EncodeToBytes(origin); err != nil { + log.Crit("Unable to decode our own headers", "err", err) + } else { + headers = append(headers, rlp.RawValue(rlpData)) + bytes += common.StorageSize(len(rlpData)) + } // Advance to the next header of the query switch { case hashMode && query.Reverse: @@ -127,6 +139,69 @@ func ServiceGetBlockHeadersQuery(chain *core.BlockChain, query *GetBlockHeadersP return headers } +func serviceContiguousBlockHeaderQuery(chain *core.BlockChain, query *GetBlockHeadersPacket) []rlp.RawValue { + count := query.Amount + if count > maxHeadersServe { + count = maxHeadersServe + } + if query.Origin.Hash == (common.Hash{}) { + // Number mode, just return the canon chain segment. The backend + // delivers in [N, N-1, N-2..] descending order, so we need to + // accommodate for that. + from := query.Origin.Number + if !query.Reverse { + from = from + count - 1 + } + headers := chain.GetHeadersFrom(from, count) + if !query.Reverse { + for i, j := 0, len(headers)-1; i < j; i, j = i+1, j-1 { + headers[i], headers[j] = headers[j], headers[i] + } + } + return headers + } + // Hash mode. + var ( + headers []rlp.RawValue + hash = query.Origin.Hash + header = chain.GetHeaderByHash(hash) + ) + if header != nil { + rlpData, _ := rlp.EncodeToBytes(header) + headers = append(headers, rlpData) + } else { + // We don't even have the origin header + return headers + } + num := header.Number.Uint64() + if !query.Reverse { + // Theoretically, we are tasked to deliver header by hash H, and onwards. + // However, if H is not canon, we will be unable to deliver any descendants of + // H. + if canonHash := chain.GetCanonicalHash(num); canonHash != hash { + // Not canon, we can't deliver descendants + return headers + } + descendants := chain.GetHeadersFrom(num+count-1, count-1) + for i, j := 0, len(descendants)-1; i < j; i, j = i+1, j-1 { + descendants[i], descendants[j] = descendants[j], descendants[i] + } + headers = append(headers, descendants...) + return headers + } + { // Last mode: deliver ancestors of H + for i := uint64(1); header != nil && i < count; i++ { + header = chain.GetHeaderByHash(header.ParentHash) + if header == nil { + break + } + rlpData, _ := rlp.EncodeToBytes(header) + headers = append(headers, rlpData) + } + return headers + } +} + func handleGetBlockBodies66(backend Backend, msg Decoder, peer *Peer) error { // Decode the block body retrieval message var query GetBlockBodiesPacket66 diff --git a/eth/protocols/eth/peer.go b/eth/protocols/eth/peer.go index 146fd8040056..a340f43903f8 100644 --- a/eth/protocols/eth/peer.go +++ b/eth/protocols/eth/peer.go @@ -297,10 +297,10 @@ func (p *Peer) AsyncSendNewBlock(block *types.Block, td *big.Int) { } // ReplyBlockHeaders is the eth/66 version of SendBlockHeaders. -func (p *Peer) ReplyBlockHeaders(id uint64, headers []*types.Header) error { - return p2p.Send(p.rw, BlockHeadersMsg, BlockHeadersPacket66{ - RequestId: id, - BlockHeadersPacket: headers, +func (p *Peer) ReplyBlockHeadersRLP(id uint64, headers []rlp.RawValue) error { + return p2p.Send(p.rw, BlockHeadersMsg, BlockHeadersRLPPacket66{ + RequestId: id, + BlockHeadersRLPPacket: headers, }) } diff --git a/eth/protocols/eth/protocol.go b/eth/protocols/eth/protocol.go index ab0685ed9cb3..c4a434ef427f 100644 --- a/eth/protocols/eth/protocol.go +++ b/eth/protocols/eth/protocol.go @@ -175,6 +175,16 @@ type BlockHeadersPacket66 struct { BlockHeadersPacket } +// BlockHeadersRLPPacket represents a block header response, to use when we already +// have the headers rlp encoded. +type BlockHeadersRLPPacket []rlp.RawValue + +// BlockHeadersPacket represents a block header response over eth/66. +type BlockHeadersRLPPacket66 struct { + RequestId uint64 + BlockHeadersRLPPacket +} + // NewBlockPacket is the network packet for the block propagation message. type NewBlockPacket struct { Block *types.Block