Update rpc client header (#9276) (#9349)

* Update rpc client header

(cherry picked from commit 2ff11e5bc2)

Co-authored-by: samricotta <37125168+samricotta@users.noreply.github.com>

CHANGELOG_PENDING.md

@@ -36,6 +36,7 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 
 ### IMPROVEMENTS
 
+- [rpc] \#9276 Added `header` and `header_by_hash` queries to the RPC client (@samricotta)
 - [abci] \#5706 Added `AbciVersion` to `RequestInfo` allowing applications to check ABCI version when connecting to Tendermint. (@marbar3778)
 
 ### BUG FIXES

consensus/replay_test.go

@@ -1164,6 +1164,7 @@ func (bs *mockBlockStore) LoadBlock(height int64) *types.Block { return bs.chain
 func (bs *mockBlockStore) LoadBlockByHash(hash []byte) *types.Block {
 	return bs.chain[int64(len(bs.chain))-1]
 }
+func (bs *mockBlockStore) LoadBlockMetaByHash(hash []byte) *types.BlockMeta { return nil }
 func (bs *mockBlockStore) LoadBlockMeta(height int64) *types.BlockMeta {
 	block := bs.chain[height-1]
 	bps, err := block.MakePartSet(types.BlockPartSizeBytes)

light/proxy/routes.go

@@ -25,6 +25,8 @@ func RPCRoutes(c *lrpc.Client) map[string]*rpcserver.RPCFunc {
 		"genesis":              rpcserver.NewRPCFunc(makeGenesisFunc(c), ""),
 		"genesis_chunked":      rpcserver.NewRPCFunc(makeGenesisChunkedFunc(c), ""),
 		"block":                rpcserver.NewRPCFunc(makeBlockFunc(c), "height"),
+		"header":               rpcserver.NewRPCFunc(makeHeaderFunc(c), "height"),
+		"header_by_hash":       rpcserver.NewRPCFunc(makeHeaderByHashFunc(c), "hash"),
 		"block_by_hash":        rpcserver.NewRPCFunc(makeBlockByHashFunc(c), "hash"),
 		"block_results":        rpcserver.NewRPCFunc(makeBlockResultsFunc(c), "height"),
 		"commit":               rpcserver.NewRPCFunc(makeCommitFunc(c), "height"),
@@ -108,6 +110,22 @@ func makeBlockFunc(c *lrpc.Client) rpcBlockFunc {
 	}
 }
 
+type rpcHeaderFunc func(ctx *rpctypes.Context, height *int64) (*ctypes.ResultHeader, error)
+
+func makeHeaderFunc(c *lrpc.Client) rpcHeaderFunc {
+	return func(ctx *rpctypes.Context, height *int64) (*ctypes.ResultHeader, error) {
+		return c.Header(ctx.Context(), height)
+	}
+}
+
+type rpcHeaderByHashFunc func(ctx *rpctypes.Context, hash []byte) (*ctypes.ResultHeader, error)
+
+func makeHeaderByHashFunc(c *lrpc.Client) rpcHeaderByHashFunc {
+	return func(ctx *rpctypes.Context, hash []byte) (*ctypes.ResultHeader, error) {
+		return c.HeaderByHash(ctx.Context(), hash)
+	}
+}
+
 type rpcBlockByHashFunc func(ctx *rpctypes.Context, hash []byte) (*ctypes.ResultBlock, error)
 
 func makeBlockByHashFunc(c *lrpc.Client) rpcBlockByHashFunc {

light/rpc/client.go

@@ -441,6 +441,40 @@ func (c *Client) BlockResults(ctx context.Context, height *int64) (*ctypes.Resul
 	return res, nil
 }
 
+// Header fetches and verifies the header directly via the light client
+func (c *Client) Header(ctx context.Context, height *int64) (*ctypes.ResultHeader, error) {
+	lb, err := c.updateLightClientIfNeededTo(ctx, height)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ctypes.ResultHeader{Header: lb.Header}, nil
+}
+
+// HeaderByHash calls rpcclient#HeaderByHash and updates the client if it's falling behind.
+func (c *Client) HeaderByHash(ctx context.Context, hash tmbytes.HexBytes) (*ctypes.ResultHeader, error) {
+	res, err := c.next.HeaderByHash(ctx, hash)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := res.Header.ValidateBasic(); err != nil {
+		return nil, err
+	}
+
+	lb, err := c.updateLightClientIfNeededTo(ctx, &res.Header.Height)
+	if err != nil {
+		return nil, err
+	}
+
+	if !bytes.Equal(lb.Header.Hash(), res.Header.Hash()) {
+		return nil, fmt.Errorf("primary header hash does not match trusted header hash. (%X != %X)",
+			lb.Header.Hash(), res.Header.Hash())
+	}
+
+	return res, nil
+}
+
 func (c *Client) Commit(ctx context.Context, height *int64) (*ctypes.ResultCommit, error) {
 	// Update the light client if we're behind and retrieve the light block at the requested height
 	// or at the latest height if no height is provided.

rpc/client/http/http.go

@@ -98,9 +98,11 @@ type baseRPCClient struct {
 	caller jsonrpcclient.Caller
 }
 
-var _ rpcClient = (*HTTP)(nil)
-var _ rpcClient = (*BatchHTTP)(nil)
-var _ rpcClient = (*baseRPCClient)(nil)
+var (
+	_ rpcClient = (*HTTP)(nil)
+	_ rpcClient = (*BatchHTTP)(nil)
+	_ rpcClient = (*baseRPCClient)(nil)
+)
 
 //-----------------------------------------------------------------------------
 // HTTP
@@ -444,6 +446,31 @@ func (c *baseRPCClient) BlockResults(
 	return result, nil
 }
 
+func (c *baseRPCClient) Header(ctx context.Context, height *int64) (*ctypes.ResultHeader, error) {
+	result := new(ctypes.ResultHeader)
+	params := make(map[string]interface{})
+	if height != nil {
+		params["height"] = height
+	}
+	_, err := c.caller.Call(ctx, "header", params, result)
+	if err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
+func (c *baseRPCClient) HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*ctypes.ResultHeader, error) {
+	result := new(ctypes.ResultHeader)
+	params := map[string]interface{}{
+		"hash": hash,
+	}
+	_, err := c.caller.Call(ctx, "header_by_hash", params, result)
+	if err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
 func (c *baseRPCClient) Commit(ctx context.Context, height *int64) (*ctypes.ResultCommit, error) {
 	result := new(ctypes.ResultCommit)
 	params := make(map[string]interface{})

rpc/client/interface.go

@@ -67,6 +67,8 @@ type SignClient interface {
 	Block(ctx context.Context, height *int64) (*ctypes.ResultBlock, error)
 	BlockByHash(ctx context.Context, hash []byte) (*ctypes.ResultBlock, error)
 	BlockResults(ctx context.Context, height *int64) (*ctypes.ResultBlockResults, error)
+	Header(ctx context.Context, height *int64) (*ctypes.ResultHeader, error)
+	HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*ctypes.ResultHeader, error)
 	Commit(ctx context.Context, height *int64) (*ctypes.ResultCommit, error)
 	Validators(ctx context.Context, height *int64, page, perPage *int) (*ctypes.ResultValidators, error)
 	Tx(ctx context.Context, hash []byte, prove bool) (*ctypes.ResultTx, error)

rpc/client/local/local.go

@@ -169,6 +169,14 @@ func (c *Local) BlockResults(ctx context.Context, height *int64) (*ctypes.Result
 	return core.BlockResults(c.ctx, height)
 }
 
+func (c *Local) Header(ctx context.Context, height *int64) (*ctypes.ResultHeader, error) {
+	return core.Header(c.ctx, height)
+}
+
+func (c *Local) HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*ctypes.ResultHeader, error) {
+	return core.HeaderByHash(c.ctx, hash)
+}
+
 func (c *Local) Commit(ctx context.Context, height *int64) (*ctypes.ResultCommit, error) {
 	return core.Commit(c.ctx, height)
 }

rpc/client/mocks/client.go

@@ -458,6 +458,51 @@ func (_m *Client) GenesisChunked(_a0 context.Context, _a1 uint) (*coretypes.Resu
 
 	return r0, r1
 }
+// Header provides a mock function with given fields: ctx, height
+func (_m *Client) Header(ctx context.Context, height *int64) (*coretypes.ResultHeader, error) {
+	ret := _m.Called(ctx, height)
+
+	var r0 *coretypes.ResultHeader
+	if rf, ok := ret.Get(0).(func(context.Context, *int64) *coretypes.ResultHeader); ok {
+		r0 = rf(ctx, height)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*coretypes.ResultHeader)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *int64) error); ok {
+		r1 = rf(ctx, height)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// HeaderByHash provides a mock function with given fields: ctx, hash
+func (_m *Client) HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*coretypes.ResultHeader, error) {
+	ret := _m.Called(ctx, hash)
+
+	var r0 *coretypes.ResultHeader
+	if rf, ok := ret.Get(0).(func(context.Context, bytes.HexBytes) *coretypes.ResultHeader); ok {
+		r0 = rf(ctx, hash)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*coretypes.ResultHeader)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, bytes.HexBytes) error); ok {
+		r1 = rf(ctx, hash)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
 
 // Health provides a mock function with given fields: _a0
 func (_m *Client) Health(_a0 context.Context) (*coretypes.ResultHealth, error) {

rpc/client/rpc_test.go

@@ -285,6 +285,15 @@ func TestAppCalls(t *testing.T) {
 		require.NoError(err)
 		require.Equal(block, blockByHash)
 
+		// check that the header matches the block hash
+		header, err := c.Header(context.Background(), &apph)
+		require.NoError(err)
+		require.Equal(block.Block.Header, *header.Header)
+
+		headerByHash, err := c.HeaderByHash(context.Background(), block.BlockID.Hash)
+		require.NoError(err)
+		require.Equal(header, headerByHash)
+
 		// now check the results
 		blockResults, err := c.BlockResults(context.Background(), &txh)
 		require.Nil(err, "%d: %+v", i, err)

rpc/core/blocks.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"sort"
 
+	"github.com/tendermint/tendermint/libs/bytes"
 	tmmath "github.com/tendermint/tendermint/libs/math"
 	tmquery "github.com/tendermint/tendermint/libs/pubsub/query"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
@@ -76,6 +77,38 @@ func filterMinMax(base, height, min, max, limit int64) (int64, int64, error) {
 	return min, max, nil
 }
 
+// Header gets block header at a given height.
+// If no height is provided, it will fetch the latest header.
+// More: https://docs.tendermint.com/master/rpc/#/Info/header
+func Header(ctx *rpctypes.Context, heightPtr *int64) (*ctypes.ResultHeader, error) {
+	height, err := getHeight(env.BlockStore.Height(), heightPtr)
+	if err != nil {
+		return nil, err
+	}
+
+	blockMeta := env.BlockStore.LoadBlockMeta(height)
+	if blockMeta == nil {
+		return &ctypes.ResultHeader{}, nil
+	}
+
+	return &ctypes.ResultHeader{Header: &blockMeta.Header}, nil
+}
+
+// HeaderByHash gets header by hash.
+// More: https://docs.tendermint.com/master/rpc/#/Info/header_by_hash
+func HeaderByHash(ctx *rpctypes.Context, hash bytes.HexBytes) (*ctypes.ResultHeader, error) {
+	// N.B. The hash parameter is HexBytes so that the reflective parameter
+	// decoding logic in the HTTP service will correctly translate from JSON.
+	// See https://github.com/tendermint/tendermint/issues/6802 for context.
+
+	blockMeta := env.BlockStore.LoadBlockMetaByHash(hash)
+	if blockMeta == nil {
+		return &ctypes.ResultHeader{}, nil
+	}
+
+	return &ctypes.ResultHeader{Header: &blockMeta.Header}, nil
+}
+
 // Block gets block at a given height.
 // If no height is provided, it will fetch the latest block.
 // More: https://docs.tendermint.com/v0.37/rpc/#/Info/block

rpc/core/blocks_test.go

@@ -14,7 +14,7 @@ import (
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	rpctypes "github.com/tendermint/tendermint/rpc/jsonrpc/types"
 	sm "github.com/tendermint/tendermint/state"
-	"github.com/tendermint/tendermint/types"
+	"github.com/tendermint/tendermint/state/mocks"
 )
 
 func TestBlockchainInfo(t *testing.T) {
@@ -86,7 +86,10 @@ func TestBlockResults(t *testing.T) {
 	})
 	err := env.StateStore.SaveABCIResponses(100, results)
 	require.NoError(t, err)
-	env.BlockStore = mockBlockStore{height: 100}
+	mockstore := &mocks.BlockStore{}
+	mockstore.On("Height").Return(int64(100))
+	mockstore.On("Base").Return(int64(1))
+	env.BlockStore = mockstore
 
 	testCases := []struct {
 		height  int64
@@ -116,21 +119,3 @@ func TestBlockResults(t *testing.T) {
 		}
 	}
 }
-
-type mockBlockStore struct {
-	height int64
-}
-
-func (mockBlockStore) Base() int64                                       { return 1 }
-func (store mockBlockStore) Height() int64                               { return store.height }
-func (store mockBlockStore) Size() int64                                 { return store.height }
-func (mockBlockStore) LoadBaseMeta() *types.BlockMeta                    { return nil }
-func (mockBlockStore) LoadBlockMeta(height int64) *types.BlockMeta       { return nil }
-func (mockBlockStore) LoadBlock(height int64) *types.Block               { return nil }
-func (mockBlockStore) LoadBlockByHash(hash []byte) *types.Block          { return nil }
-func (mockBlockStore) LoadBlockPart(height int64, index int) *types.Part { return nil }
-func (mockBlockStore) LoadBlockCommit(height int64) *types.Commit        { return nil }
-func (mockBlockStore) LoadSeenCommit(height int64) *types.Commit         { return nil }
-func (mockBlockStore) PruneBlocks(height int64) (uint64, error)          { return 0, nil }
-func (mockBlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) {
-}

rpc/core/routes.go

@@ -24,6 +24,8 @@ var Routes = map[string]*rpc.RPCFunc{
 	"block_by_hash":        rpc.NewRPCFunc(BlockByHash, "hash"),
 	"block_results":        rpc.NewRPCFunc(BlockResults, "height"),
 	"commit":               rpc.NewRPCFunc(Commit, "height"),
+	"header":               rpc.NewRPCFunc(Header, "height"),
+	"header_by_hash":       rpc.NewRPCFunc(HeaderByHash, "hash"),
 	"check_tx":             rpc.NewRPCFunc(CheckTx, "tx"),
 	"tx":                   rpc.NewRPCFunc(Tx, "hash,prove"),
 	"tx_search":            rpc.NewRPCFunc(TxSearch, "query,prove,page,per_page,order_by"),

rpc/core/types/responses.go

@@ -39,6 +39,11 @@ type ResultBlock struct {
 	Block   *types.Block  `json:"block"`
 }
 
+// ResultHeader represents the response for a Header RPC Client query
+type ResultHeader struct {
+	Header *types.Header `json:"header"`
+}
+
 // Commit and Header
 type ResultCommit struct {
 	types.SignedHeader `json:"signed_header"`

rpc/openapi/openapi.yaml

@@ -500,7 +500,7 @@ paths:
                 $ref: "#/components/schemas/ErrorResponse"
   /net_info:
     get:
-      summary: Network informations
+      summary: Network information
       operationId: net_info
       tags:
         - Info
@@ -637,6 +637,64 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/ErrorResponse"
+  /header:
+    get:
+      summary: Get header at a specified height
+      operationId: header
+      parameters:
+        - in: query
+          name: height
+          schema:
+            type: integer
+            default: 0
+            example: 1
+          description: height to return. If no height is provided, it will fetch the latest header.
+      tags:
+        - Info
+      description: |
+        Get Header.
+      responses:
+        "200":
+          description: Header informations.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/BlockHeader"
+        "500":
+          description: Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorResponse"
+  /header_by_hash:
+    get:
+      summary: Get header by hash
+      operationId: header_by_hash
+      parameters:
+        - in: query
+          name: hash
+          description: header hash
+          required: true
+          schema:
+            type: string
+            example: "0xD70952032620CC4E2737EB8AC379806359D8E0B17B0488F627997A0B043ABDED"
+      tags:
+        - Info
+      description: |
+        Get Header By Hash.
+      responses:
+        "200":
+          description: Header informations.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/BlockHeader"
+        "500":
+          description: Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorResponse"
   /block:
     get:
       summary: Get block at a specified height

state/mocks/block_store.go

@@ -121,6 +121,22 @@ func (_m *BlockStore) LoadBlockMeta(height int64) *types.BlockMeta {
 	return r0
 }
 
+// LoadBlockMetaByHash provides a mock function with given fields: hash
+func (_m *BlockStore) LoadBlockMetaByHash(hash []byte) *types.BlockMeta {
+	ret := _m.Called(hash)
+
+	var r0 *types.BlockMeta
+	if rf, ok := ret.Get(0).(func([]byte) *types.BlockMeta); ok {
+		r0 = rf(hash)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*types.BlockMeta)
+		}
+	}
+
+	return r0
+}
+
 // LoadBlockPart provides a mock function with given fields: height, index
 func (_m *BlockStore) LoadBlockPart(height int64, index int) *types.Part {
 	ret := _m.Called(height, index)

state/services.go

@@ -29,6 +29,7 @@ type BlockStore interface {
 	PruneBlocks(height int64) (uint64, error)
 
 	LoadBlockByHash(hash []byte) *types.Block
+	LoadBlockMetaByHash(hash []byte) *types.BlockMeta
 	LoadBlockPart(height int64, index int) *types.Part
 
 	LoadBlockCommit(height int64) *types.Commit

store/store.go

@@ -196,6 +196,26 @@ func (bs *BlockStore) LoadBlockMeta(height int64) *types.BlockMeta {
 	return blockMeta
 }
 
+// LoadBlockMetaByHash returns the blockmeta who's header corresponds to the given
+// hash. If none is found, returns nil.
+func (bs *BlockStore) LoadBlockMetaByHash(hash []byte) *types.BlockMeta {
+	bz, err := bs.db.Get(calcBlockHashKey(hash))
+	if err != nil {
+		panic(err)
+	}
+	if len(bz) == 0 {
+		return nil
+	}
+
+	s := string(bz)
+	height, err := strconv.ParseInt(s, 10, 64)
+
+	if err != nil {
+		panic(fmt.Sprintf("failed to extract height from %s: %v", s, err))
+	}
+	return bs.LoadBlockMeta(height)
+}
+
 // LoadBlockCommit returns the Commit for the given height.
 // This commit consists of the +2/3 and other Precommit-votes for block at `height`,
 // and it comes from the block.LastCommit for `height+1`.

store/store_test.go

@@ -476,6 +476,7 @@ func TestPruneBlocks(t *testing.T) {
 	require.Nil(t, bs.LoadBlockByHash(prunedBlock.Hash()))
 	require.Nil(t, bs.LoadBlockCommit(1199))
 	require.Nil(t, bs.LoadBlockMeta(1199))
+	require.Nil(t, bs.LoadBlockMetaByHash(prunedBlock.Hash()))
 	require.Nil(t, bs.LoadBlockPart(1199, 1))
 
 	for i := int64(1); i < 1200; i++ {
@@ -552,6 +553,28 @@ func TestLoadBlockMeta(t *testing.T) {
 	}
 }
 
+func TestLoadBlockMetaByHash(t *testing.T) {
+	config := cfg.ResetTestRoot("blockchain_reactor_test")
+	defer os.RemoveAll(config.RootDir)
+	stateStore := sm.NewStore(dbm.NewMemDB(), sm.StoreOptions{
+		DiscardABCIResponses: false,
+	})
+	state, err := stateStore.LoadFromDBOrGenesisFile(config.GenesisFile())
+	require.NoError(t, err)
+	bs := NewBlockStore(dbm.NewMemDB())
+
+	b1 := state.MakeBlock(state.LastBlockHeight+1, test.MakeNTxs(state.LastBlockHeight+1, 10), new(types.Commit), nil, state.Validators.GetProposer().Address)
+	partSet, err := b1.MakePartSet(2)
+	require.NoError(t, err)
+	seenCommit := makeTestCommit(1, tmtime.Now())
+	bs.SaveBlock(b1, partSet, seenCommit)
+
+	baseBlock := bs.LoadBlockMetaByHash(b1.Hash())
+	assert.EqualValues(t, b1.Header.Height, baseBlock.Header.Height)
+	assert.EqualValues(t, b1.Header.LastBlockID, baseBlock.Header.LastBlockID)
+	assert.EqualValues(t, b1.Header.ChainID, baseBlock.Header.ChainID)
+}
+
 func TestBlockFetchAtHeight(t *testing.T) {
 	state, bs, cleanup := makeStateAndBlockStore(log.NewTMLogger(new(bytes.Buffer)))
 	defer cleanup()