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

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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.
This commit is contained in:
Felföldi Zsolt
2017-10-24 15:19:09 +02:00
committed by Felix Lange
parent 6d6a5a9337
commit ca376ead88
34 changed files with 2056 additions and 488 deletions
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121
light/odr_util.go
View File

@ -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
}
}