eth/downloader: implement beacon sync (#23982)

* eth/downloader: implement beacon sync

* eth/downloader: fix a crash if the beacon chain is reduced in length

* eth/downloader: fix beacon sync start/stop thrashing data race

* eth/downloader: use a non-nil pivot even in degenerate sync requests

* eth/downloader: don't touch internal state on beacon Head retrieval

* eth/downloader: fix spelling mistakes

* eth/downloader: fix some typos

* eth: integrate legacy/beacon sync switchover and UX

* eth: handle UX wise being stuck on post-merge TTD

* core, eth: integrate the beacon client with the beacon sync

* eth/catalyst: make some warning messages nicer

* eth/downloader: remove Ethereum 1&2 notions in favor of merge

* core/beacon, eth: clean up engine API returns a bit

* eth/downloader: add skeleton extension tests

* eth/catalyst: keep non-kiln spec, handle mining on ttd

* eth/downloader: add beacon header retrieval tests

* eth: fixed spelling, commented failing tests out

* eth/downloader: review fixes

* eth/downloader: drop peers failing to deliver beacon headers

* core/rawdb: track beacon sync data in db inspect

* eth: fix review concerns

* internal/web3ext: nit

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>

core/rawdb/accessors_sync.go

@@ -0,0 +1,80 @@
+// Copyright 2021 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 rawdb
+
+import (
+	"bytes"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// ReadSkeletonSyncStatus retrieves the serialized sync status saved at shutdown.
+func ReadSkeletonSyncStatus(db ethdb.KeyValueReader) []byte {
+	data, _ := db.Get(skeletonSyncStatusKey)
+	return data
+}
+
+// WriteSkeletonSyncStatus stores the serialized sync status to save at shutdown.
+func WriteSkeletonSyncStatus(db ethdb.KeyValueWriter, status []byte) {
+	if err := db.Put(skeletonSyncStatusKey, status); err != nil {
+		log.Crit("Failed to store skeleton sync status", "err", err)
+	}
+}
+
+// DeleteSkeletonSyncStatus deletes the serialized sync status saved at the last
+// shutdown
+func DeleteSkeletonSyncStatus(db ethdb.KeyValueWriter) {
+	if err := db.Delete(skeletonSyncStatusKey); err != nil {
+		log.Crit("Failed to remove skeleton sync status", "err", err)
+	}
+}
+
+// ReadSkeletonHeader retrieves a block header from the skeleton sync store,
+func ReadSkeletonHeader(db ethdb.KeyValueReader, number uint64) *types.Header {
+	data, _ := db.Get(skeletonHeaderKey(number))
+	if len(data) == 0 {
+		return nil
+	}
+	header := new(types.Header)
+	if err := rlp.Decode(bytes.NewReader(data), header); err != nil {
+		log.Error("Invalid skeleton header RLP", "number", number, "err", err)
+		return nil
+	}
+	return header
+}
+
+// WriteSkeletonHeader stores a block header into the skeleton sync store.
+func WriteSkeletonHeader(db ethdb.KeyValueWriter, header *types.Header) {
+	data, err := rlp.EncodeToBytes(header)
+	if err != nil {
+		log.Crit("Failed to RLP encode header", "err", err)
+	}
+	key := skeletonHeaderKey(header.Number.Uint64())
+	if err := db.Put(key, data); err != nil {
+		log.Crit("Failed to store skeleton header", "err", err)
+	}
+}
+
+// DeleteSkeletonHeader removes all block header data associated with a hash.
+func DeleteSkeletonHeader(db ethdb.KeyValueWriter, number uint64) {
+	if err := db.Delete(skeletonHeaderKey(number)); err != nil {
+		log.Crit("Failed to delete skeleton header", "err", err)
+	}
+}

core/rawdb/database.go

@@ -331,6 +331,7 @@ func InspectDatabase(db ethdb.Database, keyPrefix, keyStart []byte) error {
 		storageSnaps    stat
 		preimages       stat
 		bloomBits       stat
+		beaconHeaders   stat
 		cliqueSnaps     stat
 
 		// Ancient store statistics
@@ -389,6 +390,8 @@ func InspectDatabase(db ethdb.Database, keyPrefix, keyStart []byte) error {
 			bloomBits.Add(size)
 		case bytes.HasPrefix(key, BloomBitsIndexPrefix):
 			bloomBits.Add(size)
+		case bytes.HasPrefix(key, skeletonHeaderPrefix) && len(key) == (len(skeletonHeaderPrefix)+8):
+			beaconHeaders.Add(size)
 		case bytes.HasPrefix(key, []byte("clique-")) && len(key) == 7+common.HashLength:
 			cliqueSnaps.Add(size)
 		case bytes.HasPrefix(key, []byte("cht-")) ||
@@ -405,7 +408,7 @@ func InspectDatabase(db ethdb.Database, keyPrefix, keyStart []byte) error {
 				databaseVersionKey, headHeaderKey, headBlockKey, headFastBlockKey, lastPivotKey,
 				fastTrieProgressKey, snapshotDisabledKey, SnapshotRootKey, snapshotJournalKey,
 				snapshotGeneratorKey, snapshotRecoveryKey, txIndexTailKey, fastTxLookupLimitKey,
-				uncleanShutdownKey, badBlockKey, transitionStatusKey,
+				uncleanShutdownKey, badBlockKey, transitionStatusKey, skeletonSyncStatusKey,
 			} {
 				if bytes.Equal(key, meta) {
 					metadata.Add(size)
@@ -451,6 +454,7 @@ func InspectDatabase(db ethdb.Database, keyPrefix, keyStart []byte) error {
 		{"Key-Value store", "Trie preimages", preimages.Size(), preimages.Count()},
 		{"Key-Value store", "Account snapshot", accountSnaps.Size(), accountSnaps.Count()},
 		{"Key-Value store", "Storage snapshot", storageSnaps.Size(), storageSnaps.Count()},
+		{"Key-Value store", "Beacon sync headers", beaconHeaders.Size(), beaconHeaders.Count()},
 		{"Key-Value store", "Clique snapshots", cliqueSnaps.Size(), cliqueSnaps.Count()},
 		{"Key-Value store", "Singleton metadata", metadata.Size(), metadata.Count()},
 		{"Ancient store", "Headers", ancientHeadersSize.String(), ancients.String()},

core/rawdb/schema.go

@@ -63,6 +63,9 @@ var (
 	// snapshotSyncStatusKey tracks the snapshot sync status across restarts.
 	snapshotSyncStatusKey = []byte("SnapshotSyncStatus")
 
+	// skeletonSyncStatusKey tracks the skeleton sync status across restarts.
+	skeletonSyncStatusKey = []byte("SkeletonSyncStatus")
+
 	// txIndexTailKey tracks the oldest block whose transactions have been indexed.
 	txIndexTailKey = []byte("TransactionIndexTail")
 
@@ -92,6 +95,7 @@ var (
 	SnapshotAccountPrefix = []byte("a") // SnapshotAccountPrefix + account hash -> account trie value
 	SnapshotStoragePrefix = []byte("o") // SnapshotStoragePrefix + account hash + storage hash -> storage trie value
 	CodePrefix            = []byte("c") // CodePrefix + code hash -> account code
+	skeletonHeaderPrefix  = []byte("S") // skeletonHeaderPrefix + num (uint64 big endian) -> header
 
 	PreimagePrefix = []byte("secure-key-")      // PreimagePrefix + hash -> preimage
 	configPrefix   = []byte("ethereum-config-") // config prefix for the db
@@ -210,6 +214,11 @@ func bloomBitsKey(bit uint, section uint64, hash common.Hash) []byte {
 	return key
 }
 
+// skeletonHeaderKey = skeletonHeaderPrefix + num (uint64 big endian)
+func skeletonHeaderKey(number uint64) []byte {
+	return append(skeletonHeaderPrefix, encodeBlockNumber(number)...)
+}
+
 // preimageKey = PreimagePrefix + hash
 func preimageKey(hash common.Hash) []byte {
 	return append(PreimagePrefix, hash.Bytes()...)