les, light: LES/2 protocol version (#14970)

This PR implements the new LES protocol version extensions:

* new and more efficient Merkle proofs reply format (when replying to
  a multiple Merkle proofs request, we just send a single set of trie
  nodes containing all necessary nodes)
* BBT (BloomBitsTrie) works similarly to the existing CHT and contains
  the bloombits search data to speed up log searches
* GetTxStatusMsg returns the inclusion position or the
  pending/queued/unknown state of a transaction referenced by hash
* an optional signature of new block data (number/hash/td) can be
  included in AnnounceMsg to provide an option for "very light
  clients" (mobile/embedded devices) to skip expensive Ethash check
  and accept multiple signatures of somewhat trusted servers (still a
  lot better than trusting a single server completely and retrieving
  everything through RPC). The new client mode is not implemented in
  this PR, just the protocol extension.

6 files changed, 571 insertions, 74 deletions

diff --git a/light/lightchain.go b/light/lightchain.go
index 4c877a771..30baeaccb 100644
--- a/light/lightchain.go
+++ b/light/lightchain.go
@@ -95,15 +95,8 @@ func NewLightChain(odr OdrBackend, config *params.ChainConfig, engine consensus.
 	if bc.genesisBlock == nil {
 		return nil, core.ErrNoGenesis
 	}
-	if bc.genesisBlock.Hash() == params.MainnetGenesisHash {
-		// add trusted CHT
-		WriteTrustedCht(bc.chainDb, TrustedCht{Number: 1040, Root: common.HexToHash("bb4fb4076cbe6923c8a8ce8f158452bbe19564959313466989fda095a60884ca")})
-		log.Info("Added trusted CHT for mainnet")
-	}
-	if bc.genesisBlock.Hash() == params.TestnetGenesisHash {
-		// add trusted CHT
-		WriteTrustedCht(bc.chainDb, TrustedCht{Number: 400, Root: common.HexToHash("2a4befa19e4675d939c3dc22dca8c6ae9fcd642be1f04b06bd6e4203cc304660")})
-		log.Info("Added trusted CHT for ropsten testnet")
+	if cp, ok := trustedCheckpoints[bc.genesisBlock.Hash()]; ok {
+		bc.addTrustedCheckpoint(cp)
 	}
 
 	if err := bc.loadLastState(); err != nil {
@@ -120,6 +113,22 @@ func NewLightChain(odr OdrBackend, config *params.ChainConfig, engine consensus.
 	return bc, nil
 }
 
+// addTrustedCheckpoint adds a trusted checkpoint to the blockchain
+func (self *LightChain) addTrustedCheckpoint(cp trustedCheckpoint) {
+	if self.odr.ChtIndexer() != nil {
+		StoreChtRoot(self.chainDb, cp.sectionIdx, cp.sectionHead, cp.chtRoot)
+		self.odr.ChtIndexer().AddKnownSectionHead(cp.sectionIdx, cp.sectionHead)
+	}
+	if self.odr.BloomTrieIndexer() != nil {
+		StoreBloomTrieRoot(self.chainDb, cp.sectionIdx, cp.sectionHead, cp.bloomTrieRoot)
+		self.odr.BloomTrieIndexer().AddKnownSectionHead(cp.sectionIdx, cp.sectionHead)
+	}
+	if self.odr.BloomIndexer() != nil {
+		self.odr.BloomIndexer().AddKnownSectionHead(cp.sectionIdx, cp.sectionHead)
+	}
+	log.Info("Added trusted checkpoint", "chain name", cp.name)
+}
+
 func (self *LightChain) getProcInterrupt() bool {
 	return atomic.LoadInt32(&self.procInterrupt) == 1
 }
@@ -449,10 +458,13 @@ func (self *LightChain) GetHeaderByNumberOdr(ctx context.Context, number uint64)
 }
 
 func (self *LightChain) SyncCht(ctx context.Context) bool {
+	if self.odr.ChtIndexer() == nil {
+		return false
+	}
 	headNum := self.CurrentHeader().Number.Uint64()
-	cht := GetTrustedCht(self.chainDb)
-	if headNum+1 < cht.Number*ChtFrequency {
-		num := cht.Number*ChtFrequency - 1
+	chtCount, _, _ := self.odr.ChtIndexer().Sections()
+	if headNum+1 < chtCount*ChtFrequency {
+		num := chtCount*ChtFrequency - 1
 		header, err := GetHeaderByNumber(ctx, self.odr, num)
 		if header != nil && err == nil {
 			self.mu.Lock()
diff --git a/light/nodeset.go b/light/nodeset.go
new file mode 100644
index 000000000..c530a4fbe
--- /dev/null
+++ b/light/nodeset.go
@@ -0,0 +1,141 @@
+// Copyright 2014 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 light
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+// NodeSet stores a set of trie nodes. It implements trie.Database and can also
+// act as a cache for another trie.Database.
+type NodeSet struct {
+	db       map[string][]byte
+	dataSize int
+	lock     sync.RWMutex
+}
+
+// NewNodeSet creates an empty node set
+func NewNodeSet() *NodeSet {
+	return &NodeSet{
+		db: make(map[string][]byte),
+	}
+}
+
+// Put stores a new node in the set
+func (db *NodeSet) Put(key []byte, value []byte) error {
+	db.lock.Lock()
+	defer db.lock.Unlock()
+
+	if _, ok := db.db[string(key)]; !ok {
+		db.db[string(key)] = common.CopyBytes(value)
+		db.dataSize += len(value)
+	}
+	return nil
+}
+
+// Get returns a stored node
+func (db *NodeSet) Get(key []byte) ([]byte, error) {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	if entry, ok := db.db[string(key)]; ok {
+		return entry, nil
+	}
+	return nil, errors.New("not found")
+}
+
+// Has returns true if the node set contains the given key
+func (db *NodeSet) Has(key []byte) (bool, error) {
+	_, err := db.Get(key)
+	return err == nil, nil
+}
+
+// KeyCount returns the number of nodes in the set
+func (db *NodeSet) KeyCount() int {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	return len(db.db)
+}
+
+// DataSize returns the aggregated data size of nodes in the set
+func (db *NodeSet) DataSize() int {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	return db.dataSize
+}
+
+// NodeList converts the node set to a NodeList
+func (db *NodeSet) NodeList() NodeList {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	var values NodeList
+	for _, value := range db.db {
+		values = append(values, value)
+	}
+	return values
+}
+
+// Store writes the contents of the set to the given database
+func (db *NodeSet) Store(target trie.Database) {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	for key, value := range db.db {
+		target.Put([]byte(key), value)
+	}
+}
+
+// NodeList stores an ordered list of trie nodes. It implements trie.DatabaseWriter.
+type NodeList []rlp.RawValue
+
+// Store writes the contents of the list to the given database
+func (n NodeList) Store(db trie.Database) {
+	for _, node := range n {
+		db.Put(crypto.Keccak256(node), node)
+	}
+}
+
+// NodeSet converts the node list to a NodeSet
+func (n NodeList) NodeSet() *NodeSet {
+	db := NewNodeSet()
+	n.Store(db)
+	return db
+}
+
+// Put stores a new node at the end of the list
+func (n *NodeList) Put(key []byte, value []byte) error {
+	*n = append(*n, value)
+	return nil
+}
+
+// DataSize returns the aggregated data size of nodes in the list
+func (n NodeList) DataSize() int {
+	var size int
+	for _, node := range n {
+		size += len(node)
+	}
+	return size
+}
diff --git a/light/odr.go b/light/odr.go
index d19a488f6..e2c3d9c5a 100644
--- a/light/odr.go
+++ b/light/odr.go
@@ -25,9 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 // NoOdr is the default context passed to an ODR capable function when the ODR
@@ -37,6 +35,9 @@ var NoOdr = context.Background()
 // OdrBackend is an interface to a backend service that handles ODR retrievals type
 type OdrBackend interface {
 	Database() ethdb.Database
+	ChtIndexer() *core.ChainIndexer
+	BloomTrieIndexer() *core.ChainIndexer
+	BloomIndexer() *core.ChainIndexer
 	Retrieve(ctx context.Context, req OdrRequest) error
 }
 
@@ -80,23 +81,12 @@ type TrieRequest struct {
 	OdrRequest
 	Id    *TrieID
 	Key   []byte
-	Proof []rlp.RawValue
+	Proof *NodeSet
 }
 
 // StoreResult stores the retrieved data in local database
 func (req *TrieRequest) StoreResult(db ethdb.Database) {
-	storeProof(db, req.Proof)
-}
-
-// storeProof stores the new trie nodes obtained from a merkle proof in the database
-func storeProof(db ethdb.Database, proof []rlp.RawValue) {
-	for _, buf := range proof {
-		hash := crypto.Keccak256(buf)
-		val, _ := db.Get(hash)
-		if val == nil {
-			db.Put(hash, buf)
-		}
-	}
+	req.Proof.Store(db)
 }
 
 // CodeRequest is the ODR request type for retrieving contract code
@@ -138,14 +128,14 @@ func (req *ReceiptsRequest) StoreResult(db ethdb.Database) {
 	core.WriteBlockReceipts(db, req.Hash, req.Number, req.Receipts)
 }
 
-// TrieRequest is the ODR request type for state/storage trie entries
+// ChtRequest is the ODR request type for state/storage trie entries
 type ChtRequest struct {
 	OdrRequest
 	ChtNum, BlockNum uint64
 	ChtRoot          common.Hash
 	Header           *types.Header
 	Td               *big.Int
-	Proof            []rlp.RawValue
+	Proof            *NodeSet
 }
 
 // StoreResult stores the retrieved data in local database
@@ -155,5 +145,27 @@ func (req *ChtRequest) StoreResult(db ethdb.Database) {
 	hash, num := req.Header.Hash(), req.Header.Number.Uint64()
 	core.WriteTd(db, hash, num, req.Td)
 	core.WriteCanonicalHash(db, hash, num)
-	//storeProof(db, req.Proof)
+}
+
+// BloomRequest is the ODR request type for retrieving bloom filters from a CHT structure
+type BloomRequest struct {
+	OdrRequest
+	BloomTrieNum   uint64
+	BitIdx         uint
+	SectionIdxList []uint64
+	BloomTrieRoot  common.Hash
+	BloomBits      [][]byte
+	Proofs         *NodeSet
+}
+
+// StoreResult stores the retrieved data in local database
+func (req *BloomRequest) StoreResult(db ethdb.Database) {
+	for i, sectionIdx := range req.SectionIdxList {
+		sectionHead := core.GetCanonicalHash(db, (sectionIdx+1)*BloomTrieFrequency-1)
+		// if we don't have the canonical hash stored for this section head number, we'll still store it under
+		// a key with a zero sectionHead. GetBloomBits will look there too if we still don't have the canonical
+		// hash. In the unlikely case we've retrieved the section head hash since then, we'll just retrieve the
+		// bit vector again from the network.
+		core.WriteBloomBits(db, req.BitIdx, sectionIdx, sectionHead, req.BloomBits[i])
+	}
 }
diff --git a/light/odr_test.go b/light/odr_test.go
index c0c5438fd..e6afb1a48 100644
--- a/light/odr_test.go
+++ b/light/odr_test.go
@@ -77,7 +77,9 @@ func (odr *testOdr) Retrieve(ctx context.Context, req OdrRequest) error {
 		req.Receipts = core.GetBlockReceipts(odr.sdb, req.Hash, core.GetBlockNumber(odr.sdb, req.Hash))
 	case *TrieRequest:
 		t, _ := trie.New(req.Id.Root, odr.sdb)
-		req.Proof = t.Prove(req.Key)
+		nodes := NewNodeSet()
+		t.Prove(req.Key, 0, nodes)
+		req.Proof = nodes
 	case *CodeRequest:
 		req.Data, _ = odr.sdb.Get(req.Hash[:])
 	}
diff --git a/light/odr_util.go b/light/odr_util.go
index fcdfdb82c..a0eb6303d 100644
--- a/light/odr_util.go
+++ b/light/odr_util.go
@@ -19,56 +19,16 @@ package light
 import (
 	"bytes"
 	"context"
-	"errors"
-	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
 var sha3_nil = crypto.Keccak256Hash(nil)
 
-var (
-	ErrNoTrustedCht = errors.New("No trusted canonical hash trie")
-	ErrNoHeader     = errors.New("Header not found")
-
-	ChtFrequency     = uint64(4096)
-	ChtConfirmations = uint64(2048)
-	trustedChtKey    = []byte("TrustedCHT")
-)
-
-type ChtNode struct {
-	Hash common.Hash
-	Td   *big.Int
-}
-
-type TrustedCht struct {
-	Number uint64
-	Root   common.Hash
-}
-
-func GetTrustedCht(db ethdb.Database) TrustedCht {
-	data, _ := db.Get(trustedChtKey)
-	var res TrustedCht
-	if err := rlp.DecodeBytes(data, &res); err != nil {
-		return TrustedCht{0, common.Hash{}}
-	}
-	return res
-}
-
-func WriteTrustedCht(db ethdb.Database, cht TrustedCht) {
-	data, _ := rlp.EncodeToBytes(cht)
-	db.Put(trustedChtKey, data)
-}
-
-func DeleteTrustedCht(db ethdb.Database) {
-	db.Delete(trustedChtKey)
-}
-
 func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*types.Header, error) {
 	db := odr.Database()
 	hash := core.GetCanonicalHash(db, number)
@@ -81,12 +41,29 @@ func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*typ
 		return header, nil
 	}
 
-	cht := GetTrustedCht(db)
-	if number >= cht.Number*ChtFrequency {
+	var (
+		chtCount, sectionHeadNum uint64
+		sectionHead              common.Hash
+	)
+	if odr.ChtIndexer() != nil {
+		chtCount, sectionHeadNum, sectionHead = odr.ChtIndexer().Sections()
+		canonicalHash := core.GetCanonicalHash(db, sectionHeadNum)
+		// if the CHT was injected as a trusted checkpoint, we have no canonical hash yet so we accept zero hash too
+		for chtCount > 0 && canonicalHash != sectionHead && canonicalHash != (common.Hash{}) {
+			chtCount--
+			if chtCount > 0 {
+				sectionHeadNum = chtCount*ChtFrequency - 1
+				sectionHead = odr.ChtIndexer().SectionHead(chtCount - 1)
+				canonicalHash = core.GetCanonicalHash(db, sectionHeadNum)
+			}
+		}
+	}
+
+	if number >= chtCount*ChtFrequency {
 		return nil, ErrNoTrustedCht
 	}
 
-	r := &ChtRequest{ChtRoot: cht.Root, ChtNum: cht.Number, BlockNum: number}
+	r := &ChtRequest{ChtRoot: GetChtRoot(db, chtCount-1, sectionHead), ChtNum: chtCount - 1, BlockNum: number}
 	if err := odr.Retrieve(ctx, r); err != nil {
 		return nil, err
 	} else {
@@ -162,3 +139,61 @@ func GetBlockReceipts(ctx context.Context, odr OdrBackend, hash common.Hash, num
 	}
 	return r.Receipts, nil
 }
+
+// GetBloomBits retrieves a batch of compressed bloomBits vectors belonging to the given bit index and section indexes
+func GetBloomBits(ctx context.Context, odr OdrBackend, bitIdx uint, sectionIdxList []uint64) ([][]byte, error) {
+	db := odr.Database()
+	result := make([][]byte, len(sectionIdxList))
+	var (
+		reqList []uint64
+		reqIdx  []int
+	)
+
+	var (
+		bloomTrieCount, sectionHeadNum uint64
+		sectionHead                    common.Hash
+	)
+	if odr.BloomTrieIndexer() != nil {
+		bloomTrieCount, sectionHeadNum, sectionHead = odr.BloomTrieIndexer().Sections()
+		canonicalHash := core.GetCanonicalHash(db, sectionHeadNum)
+		// if the BloomTrie was injected as a trusted checkpoint, we have no canonical hash yet so we accept zero hash too
+		for bloomTrieCount > 0 && canonicalHash != sectionHead && canonicalHash != (common.Hash{}) {
+			bloomTrieCount--
+			if bloomTrieCount > 0 {
+				sectionHeadNum = bloomTrieCount*BloomTrieFrequency - 1
+				sectionHead = odr.BloomTrieIndexer().SectionHead(bloomTrieCount - 1)
+				canonicalHash = core.GetCanonicalHash(db, sectionHeadNum)
+			}
+		}
+	}
+
+	for i, sectionIdx := range sectionIdxList {
+		sectionHead := core.GetCanonicalHash(db, (sectionIdx+1)*BloomTrieFrequency-1)
+		// if we don't have the canonical hash stored for this section head number, we'll still look for
+		// an entry with a zero sectionHead (we store it with zero section head too if we don't know it
+		// at the time of the retrieval)
+		bloomBits, err := core.GetBloomBits(db, bitIdx, sectionIdx, sectionHead)
+		if err == nil {
+			result[i] = bloomBits
+		} else {
+			if sectionIdx >= bloomTrieCount {
+				return nil, ErrNoTrustedBloomTrie
+			}
+			reqList = append(reqList, sectionIdx)
+			reqIdx = append(reqIdx, i)
+		}
+	}
+	if reqList == nil {
+		return result, nil
+	}
+
+	r := &BloomRequest{BloomTrieRoot: GetBloomTrieRoot(db, bloomTrieCount-1, sectionHead), BloomTrieNum: bloomTrieCount - 1, BitIdx: bitIdx, SectionIdxList: reqList}
+	if err := odr.Retrieve(ctx, r); err != nil {
+		return nil, err
+	} else {
+		for i, idx := range reqIdx {
+			result[idx] = r.BloomBits[i]
+		}
+		return result, nil
+	}
+}
diff --git a/light/postprocess.go b/light/postprocess.go
new file mode 100644
index 000000000..e7e513880
--- /dev/null
+++ b/light/postprocess.go
@@ -0,0 +1,295 @@
+// Copyright 2016 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 light
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/bitutil"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+const (
+	ChtFrequency                   = 32768
+	ChtV1Frequency                 = 4096 // as long as we want to retain LES/1 compatibility, servers generate CHTs with the old, higher frequency
+	HelperTrieConfirmations        = 2048 // number of confirmations before a server is expected to have the given HelperTrie available
+	HelperTrieProcessConfirmations = 256  // number of confirmations before a HelperTrie is generated
+)
+
+// trustedCheckpoint represents a set of post-processed trie roots (CHT and BloomTrie) associated with
+// the appropriate section index and head hash. It is used to start light syncing from this checkpoint
+// and avoid downloading the entire header chain while still being able to securely access old headers/logs.
+type trustedCheckpoint struct {
+	name                                string
+	sectionIdx                          uint64
+	sectionHead, chtRoot, bloomTrieRoot common.Hash
+}
+
+var (
+	mainnetCheckpoint = trustedCheckpoint{
+		name:          "ETH mainnet",
+		sectionIdx:    129,
+		sectionHead:   common.HexToHash("64100587c8ec9a76870056d07cb0f58622552d16de6253a59cac4b580c899501"),
+		chtRoot:       common.HexToHash("bb4fb4076cbe6923c8a8ce8f158452bbe19564959313466989fda095a60884ca"),
+		bloomTrieRoot: common.HexToHash("0db524b2c4a2a9520a42fd842b02d2e8fb58ff37c75cf57bd0eb82daeace6716"),
+	}
+
+	ropstenCheckpoint = trustedCheckpoint{
+		name:          "Ropsten testnet",
+		sectionIdx:    50,
+		sectionHead:   common.HexToHash("00bd65923a1aa67f85e6b4ae67835784dd54be165c37f056691723c55bf016bd"),
+		chtRoot:       common.HexToHash("6f56dc61936752cc1f8c84b4addabdbe6a1c19693de3f21cb818362df2117f03"),
+		bloomTrieRoot: common.HexToHash("aca7d7c504d22737242effc3fdc604a762a0af9ced898036b5986c3a15220208"),
+	}
+)
+
+// trustedCheckpoints associates each known checkpoint with the genesis hash of the chain it belongs to
+var trustedCheckpoints = map[common.Hash]trustedCheckpoint{
+	params.MainnetGenesisHash: mainnetCheckpoint,
+	params.TestnetGenesisHash: ropstenCheckpoint,
+}
+
+var (
+	ErrNoTrustedCht       = errors.New("No trusted canonical hash trie")
+	ErrNoTrustedBloomTrie = errors.New("No trusted bloom trie")
+	ErrNoHeader           = errors.New("Header not found")
+	chtPrefix             = []byte("chtRoot-") // chtPrefix + chtNum (uint64 big endian) -> trie root hash
+	ChtTablePrefix        = "cht-"
+)
+
+// ChtNode structures are stored in the Canonical Hash Trie in an RLP encoded format
+type ChtNode struct {
+	Hash common.Hash
+	Td   *big.Int
+}
+
+// GetChtRoot reads the CHT root assoctiated to the given section from the database
+// Note that sectionIdx is specified according to LES/1 CHT section size
+func GetChtRoot(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
+	data, _ := db.Get(append(append(chtPrefix, encNumber[:]...), sectionHead.Bytes()...))
+	return common.BytesToHash(data)
+}
+
+// GetChtV2Root reads the CHT root assoctiated to the given section from the database
+// Note that sectionIdx is specified according to LES/2 CHT section size
+func GetChtV2Root(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
+	return GetChtRoot(db, (sectionIdx+1)*(ChtFrequency/ChtV1Frequency)-1, sectionHead)
+}
+
+// StoreChtRoot writes the CHT root assoctiated to the given section into the database
+// Note that sectionIdx is specified according to LES/1 CHT section size
+func StoreChtRoot(db ethdb.Database, sectionIdx uint64, sectionHead, root common.Hash) {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
+	db.Put(append(append(chtPrefix, encNumber[:]...), sectionHead.Bytes()...), root.Bytes())
+}
+
+// ChtIndexerBackend implements core.ChainIndexerBackend
+type ChtIndexerBackend struct {
+	db, cdb              ethdb.Database
+	section, sectionSize uint64
+	lastHash             common.Hash
+	trie                 *trie.Trie
+}
+
+// NewBloomTrieIndexer creates a BloomTrie chain indexer
+func NewChtIndexer(db ethdb.Database, clientMode bool) *core.ChainIndexer {
+	cdb := ethdb.NewTable(db, ChtTablePrefix)
+	idb := ethdb.NewTable(db, "chtIndex-")
+	var sectionSize, confirmReq uint64
+	if clientMode {
+		sectionSize = ChtFrequency
+		confirmReq = HelperTrieConfirmations
+	} else {
+		sectionSize = ChtV1Frequency
+		confirmReq = HelperTrieProcessConfirmations
+	}
+	return core.NewChainIndexer(db, idb, &ChtIndexerBackend{db: db, cdb: cdb, sectionSize: sectionSize}, sectionSize, confirmReq, time.Millisecond*100, "cht")
+}
+
+// Reset implements core.ChainIndexerBackend
+func (c *ChtIndexerBackend) Reset(section uint64, lastSectionHead common.Hash) error {
+	var root common.Hash
+	if section > 0 {
+		root = GetChtRoot(c.db, section-1, lastSectionHead)
+	}
+	var err error
+	c.trie, err = trie.New(root, c.cdb)
+	c.section = section
+	return err
+}
+
+// Process implements core.ChainIndexerBackend
+func (c *ChtIndexerBackend) Process(header *types.Header) {
+	hash, num := header.Hash(), header.Number.Uint64()
+	c.lastHash = hash
+
+	td := core.GetTd(c.db, hash, num)
+	if td == nil {
+		panic(nil)
+	}
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], num)
+	data, _ := rlp.EncodeToBytes(ChtNode{hash, td})
+	c.trie.Update(encNumber[:], data)
+}
+
+// Commit implements core.ChainIndexerBackend
+func (c *ChtIndexerBackend) Commit() error {
+	batch := c.cdb.NewBatch()
+	root, err := c.trie.CommitTo(batch)
+	if err != nil {
+		return err
+	} else {
+		batch.Write()
+		if ((c.section+1)*c.sectionSize)%ChtFrequency == 0 {
+			log.Info("Storing CHT", "idx", c.section*c.sectionSize/ChtFrequency, "sectionHead", fmt.Sprintf("%064x", c.lastHash), "root", fmt.Sprintf("%064x", root))
+		}
+		StoreChtRoot(c.db, c.section, c.lastHash, root)
+	}
+	return nil
+}
+
+const (
+	BloomTrieFrequency        = 32768
+	ethBloomBitsSection       = 4096
+	ethBloomBitsConfirmations = 256
+)
+
+var (
+	bloomTriePrefix      = []byte("bltRoot-") // bloomTriePrefix + bloomTrieNum (uint64 big endian) -> trie root hash
+	BloomTrieTablePrefix = "blt-"
+)
+
+// GetBloomTrieRoot reads the BloomTrie root assoctiated to the given section from the database
+func GetBloomTrieRoot(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
+	data, _ := db.Get(append(append(bloomTriePrefix, encNumber[:]...), sectionHead.Bytes()...))
+	return common.BytesToHash(data)
+}
+
+// StoreBloomTrieRoot writes the BloomTrie root assoctiated to the given section into the database
+func StoreBloomTrieRoot(db ethdb.Database, sectionIdx uint64, sectionHead, root common.Hash) {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], sectionIdx)
+	db.Put(append(append(bloomTriePrefix, encNumber[:]...), sectionHead.Bytes()...), root.Bytes())
+}
+
+// BloomTrieIndexerBackend implements core.ChainIndexerBackend
+type BloomTrieIndexerBackend struct {
+	db, cdb                                    ethdb.Database
+	section, parentSectionSize, bloomTrieRatio uint64
+	trie                                       *trie.Trie
+	sectionHeads                               []common.Hash
+}
+
+// NewBloomTrieIndexer creates a BloomTrie chain indexer
+func NewBloomTrieIndexer(db ethdb.Database, clientMode bool) *core.ChainIndexer {
+	cdb := ethdb.NewTable(db, BloomTrieTablePrefix)
+	idb := ethdb.NewTable(db, "bltIndex-")
+	backend := &BloomTrieIndexerBackend{db: db, cdb: cdb}
+	var confirmReq uint64
+	if clientMode {
+		backend.parentSectionSize = BloomTrieFrequency
+		confirmReq = HelperTrieConfirmations
+	} else {
+		backend.parentSectionSize = ethBloomBitsSection
+		confirmReq = HelperTrieProcessConfirmations
+	}
+	backend.bloomTrieRatio = BloomTrieFrequency / backend.parentSectionSize
+	backend.sectionHeads = make([]common.Hash, backend.bloomTrieRatio)
+	return core.NewChainIndexer(db, idb, backend, BloomTrieFrequency, confirmReq-ethBloomBitsConfirmations, time.Millisecond*100, "bloomtrie")
+}
+
+// Reset implements core.ChainIndexerBackend
+func (b *BloomTrieIndexerBackend) Reset(section uint64, lastSectionHead common.Hash) error {
+	var root common.Hash
+	if section > 0 {
+		root = GetBloomTrieRoot(b.db, section-1, lastSectionHead)
+	}
+	var err error
+	b.trie, err = trie.New(root, b.cdb)
+	b.section = section
+	return err
+}
+
+// Process implements core.ChainIndexerBackend
+func (b *BloomTrieIndexerBackend) Process(header *types.Header) {
+	num := header.Number.Uint64() - b.section*BloomTrieFrequency
+	if (num+1)%b.parentSectionSize == 0 {
+		b.sectionHeads[num/b.parentSectionSize] = header.Hash()
+	}
+}
+
+// Commit implements core.ChainIndexerBackend
+func (b *BloomTrieIndexerBackend) Commit() error {
+	var compSize, decompSize uint64
+
+	for i := uint(0); i < types.BloomBitLength; i++ {
+		var encKey [10]byte
+		binary.BigEndian.PutUint16(encKey[0:2], uint16(i))
+		binary.BigEndian.PutUint64(encKey[2:10], b.section)
+		var decomp []byte
+		for j := uint64(0); j < b.bloomTrieRatio; j++ {
+			data, err := core.GetBloomBits(b.db, i, b.section*b.bloomTrieRatio+j, b.sectionHeads[j])
+			if err != nil {
+				return err
+			}
+			decompData, err2 := bitutil.DecompressBytes(data, int(b.parentSectionSize/8))
+			if err2 != nil {
+				return err2
+			}
+			decomp = append(decomp, decompData...)
+		}
+		comp := bitutil.CompressBytes(decomp)
+
+		decompSize += uint64(len(decomp))
+		compSize += uint64(len(comp))
+		if len(comp) > 0 {
+			b.trie.Update(encKey[:], comp)
+		} else {
+			b.trie.Delete(encKey[:])
+		}
+	}
+
+	batch := b.cdb.NewBatch()
+	root, err := b.trie.CommitTo(batch)
+	if err != nil {
+		return err
+	} else {
+		batch.Write()
+		sectionHead := b.sectionHeads[b.bloomTrieRatio-1]
+		log.Info("Storing BloomTrie", "section", b.section, "sectionHead", fmt.Sprintf("%064x", sectionHead), "root", fmt.Sprintf("%064x", root), "compression ratio", float64(compSize)/float64(decompSize))
+		StoreBloomTrieRoot(b.db, b.section, sectionHead, root)
+	}
+
+	return nil
+}