les, light: remove untrusted header retrieval in ODR (#21907)

* les, light: remove untrusted header retrieval in ODR

* les: polish

* light: check the hash equality in odr

light/odr.go

@@ -135,8 +135,6 @@ func (req *ReceiptsRequest) StoreResult(db ethdb.Database) {
 
 // ChtRequest is the ODR request type for retrieving header by Canonical Hash Trie
 type ChtRequest struct {
-	Untrusted        bool   // Indicator whether the result retrieved is trusted or not
-	PeerId           string // The specified peer id from which to retrieve data.
 	Config           *IndexerConfig
 	ChtNum, BlockNum uint64
 	ChtRoot          common.Hash
@@ -148,12 +146,9 @@ type ChtRequest struct {
 // StoreResult stores the retrieved data in local database
 func (req *ChtRequest) StoreResult(db ethdb.Database) {
 	hash, num := req.Header.Hash(), req.Header.Number.Uint64()
-
-	if !req.Untrusted {
-		rawdb.WriteHeader(db, req.Header)
-		rawdb.WriteTd(db, hash, num, req.Td)
-		rawdb.WriteCanonicalHash(db, hash, num)
-	}
+	rawdb.WriteHeader(db, req.Header)
+	rawdb.WriteTd(db, hash, num, req.Td)
+	rawdb.WriteCanonicalHash(db, hash, num)
 }
 
 // BloomRequest is the ODR request type for retrieving bloom filters from a CHT structure

light/odr_util.go

@@ -19,20 +19,23 @@ 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/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-var sha3Nil = crypto.Keccak256Hash(nil)
+// errNonCanonicalHash is returned if the requested chain data doesn't belong
+// to the canonical chain. ODR can only retrieve the canonical chain data covered
+// by the CHT or Bloom trie for verification.
+var errNonCanonicalHash = errors.New("hash is not currently canonical")
 
 // GetHeaderByNumber retrieves the canonical block header corresponding to the
-// given number.
+// given number. The returned header is proven by local CHT.
 func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*types.Header, error) {
 	// Try to find it in the local database first.
 	db := odr.Database()
@@ -63,25 +66,6 @@ func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*typ
 	return r.Header, nil
 }
 
-// GetUntrustedHeaderByNumber retrieves specified block header without
-// correctness checking. Note this function should only be used in light
-// client checkpoint syncing.
-func GetUntrustedHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64, peerId string) (*types.Header, error) {
-	// todo(rjl493456442) it's a hack to retrieve headers which is not covered
-	// by CHT. Fix it in LES4
-	r := &ChtRequest{
-		BlockNum:  number,
-		ChtNum:    number / odr.IndexerConfig().ChtSize,
-		Untrusted: true,
-		PeerId:    peerId,
-		Config:    odr.IndexerConfig(),
-	}
-	if err := odr.Retrieve(ctx, r); err != nil {
-		return nil, err
-	}
-	return r.Header, nil
-}
-
 // GetCanonicalHash retrieves the canonical block hash corresponding to the number.
 func GetCanonicalHash(ctx context.Context, odr OdrBackend, number uint64) (common.Hash, error) {
 	hash := rawdb.ReadCanonicalHash(odr.Database(), number)
@@ -102,10 +86,13 @@ func GetTd(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64)
 	if td != nil {
 		return td, nil
 	}
-	_, err := GetHeaderByNumber(ctx, odr, number)
+	header, err := GetHeaderByNumber(ctx, odr, number)
 	if err != nil {
 		return nil, err
 	}
+	if header.Hash() != hash {
+		return nil, errNonCanonicalHash
+	}
 	// <hash, number> -> td mapping already be stored in db, get it.
 	return rawdb.ReadTd(odr.Database(), hash, number), nil
 }
@@ -120,6 +107,9 @@ func GetBodyRLP(ctx context.Context, odr OdrBackend, hash common.Hash, number ui
 	if err != nil {
 		return nil, errNoHeader
 	}
+	if header.Hash() != hash {
+		return nil, errNonCanonicalHash
+	}
 	r := &BlockRequest{Hash: hash, Number: number, Header: header}
 	if err := odr.Retrieve(ctx, r); err != nil {
 		return nil, err
@@ -167,6 +157,9 @@ func GetBlockReceipts(ctx context.Context, odr OdrBackend, hash common.Hash, num
 		if err != nil {
 			return nil, errNoHeader
 		}
+		if header.Hash() != hash {
+			return nil, errNonCanonicalHash
+		}
 		r := &ReceiptsRequest{Hash: hash, Number: number, Header: header}
 		if err := odr.Retrieve(ctx, r); err != nil {
 			return nil, err

light/trie.go

@@ -30,6 +30,10 @@ import (
 	"github.com/ethereum/go-ethereum/trie"
 )
 
+var (
+	sha3Nil = crypto.Keccak256Hash(nil)
+)
+
 func NewState(ctx context.Context, head *types.Header, odr OdrBackend) *state.StateDB {
 	state, _ := state.New(head.Root, NewStateDatabase(ctx, head, odr), nil)
 	return state