rpc: implement header and header_by_hash queries (#7270)

CHANGELOG_PENDING.md

@@ -39,6 +39,7 @@ Special thanks to external contributors on this release:
 
 ### FEATURES
 
+- [rpc] [\#7270](https://github.com/tendermint/tendermint/pull/7270) Add `header` and `header_by_hash` RPC Client queries. (@fedekunze)
 - [cli] [#7033](https://github.com/tendermint/tendermint/pull/7033) Add a `rollback` command to rollback to the previous tendermint state in the event of non-determinstic app hash or reverting an upgrade.
 - [mempool, rpc] \#7041  Add removeTx operation to the RPC layer. (@tychoish)
 

internal/consensus/replay_test.go

@@ -1241,6 +1241,7 @@ 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]
 	return &types.BlockMeta{

internal/rpc/core/blocks.go

@@ -51,7 +51,8 @@ func (env *Environment) BlockchainInfo(
 
 	return &coretypes.ResultBlockchainInfo{
 		LastHeight: env.BlockStore.Height(),
-		BlockMetas: blockMetas}, nil
+		BlockMetas: blockMetas,
+	}, nil
 }
 
 // error if either min or max are negative or min > max
@@ -122,6 +123,38 @@ func (env *Environment) BlockByHash(ctx *rpctypes.Context, hash bytes.HexBytes)
 	return &coretypes.ResultBlock{BlockID: blockMeta.BlockID, Block: block}, 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 (env *Environment) Header(ctx *rpctypes.Context, heightPtr *int64) (*coretypes.ResultHeader, error) {
+	height, err := env.getHeight(env.BlockStore.Height(), heightPtr)
+	if err != nil {
+		return nil, err
+	}
+
+	blockMeta := env.BlockStore.LoadBlockMeta(height)
+	if blockMeta == nil {
+		return &coretypes.ResultHeader{}, nil
+	}
+
+	return &coretypes.ResultHeader{Header: &blockMeta.Header}, nil
+}
+
+// HeaderByHash gets header by hash.
+// More: https://docs.tendermint.com/master/rpc/#/Info/header_by_hash
+func (env *Environment) HeaderByHash(ctx *rpctypes.Context, hash bytes.HexBytes) (*coretypes.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 &coretypes.ResultHeader{}, nil
+	}
+
+	return &coretypes.ResultHeader{Header: &blockMeta.Header}, nil
+}
+
 // Commit gets block commit at a given height.
 // If no height is provided, it will fetch the commit for the latest block.
 // More: https://docs.tendermint.com/master/rpc/#/Info/commit

internal/rpc/core/blocks_test.go

@@ -11,10 +11,10 @@ import (
 
 	abci "github.com/tendermint/tendermint/abci/types"
 	sm "github.com/tendermint/tendermint/internal/state"
+	"github.com/tendermint/tendermint/internal/state/mocks"
 	tmstate "github.com/tendermint/tendermint/proto/tendermint/state"
 	"github.com/tendermint/tendermint/rpc/coretypes"
 	rpctypes "github.com/tendermint/tendermint/rpc/jsonrpc/types"
-	"github.com/tendermint/tendermint/types"
 )
 
 func TestBlockchainInfo(t *testing.T) {
@@ -84,7 +84,10 @@ func TestBlockResults(t *testing.T) {
 	env.StateStore = sm.NewStore(dbm.NewMemDB())
 	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
@@ -115,21 +118,3 @@ 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() *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) {
-}

internal/rpc/core/routes.go

@@ -23,6 +23,8 @@ func (env *Environment) GetRoutes() RoutesMap {
 		"blockchain":           rpc.NewRPCFunc(env.BlockchainInfo, "minHeight,maxHeight", true),
 		"genesis":              rpc.NewRPCFunc(env.Genesis, "", true),
 		"genesis_chunked":      rpc.NewRPCFunc(env.GenesisChunked, "chunk", true),
+		"header":               rpc.NewRPCFunc(env.Header, "height", true),
+		"header_by_hash":       rpc.NewRPCFunc(env.HeaderByHash, "hash", true),
 		"block":                rpc.NewRPCFunc(env.Block, "height", true),
 		"block_by_hash":        rpc.NewRPCFunc(env.BlockByHash, "hash", true),
 		"block_results":        rpc.NewRPCFunc(env.BlockResults, "height", true),

internal/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)

internal/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

internal/store/store.go

@@ -181,6 +181,26 @@ func (bs *BlockStore) LoadBlockByHash(hash []byte) *types.Block {
 	return bs.LoadBlock(height)
 }
 
+// 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(blockHashKey(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)
+}
+
 // LoadBlockPart returns the Part at the given index
 // from the block at the given height.
 // If no part is found for the given height and index, it returns nil.

light/proxy/routes.go

@@ -24,6 +24,8 @@ func RPCRoutes(c *lrpc.Client) map[string]*rpcserver.RPCFunc {
 		"blockchain":           rpcserver.NewRPCFunc(makeBlockchainInfoFunc(c), "minHeight,maxHeight", true),
 		"genesis":              rpcserver.NewRPCFunc(makeGenesisFunc(c), "", true),
 		"genesis_chunked":      rpcserver.NewRPCFunc(makeGenesisChunkedFunc(c), "", true),
+		"header":               rpcserver.NewRPCFunc(makeHeaderFunc(c), "height", true),
+		"header_by_hash":       rpcserver.NewRPCFunc(makeHeaderByHashFunc(c), "hash", true),
 		"block":                rpcserver.NewRPCFunc(makeBlockFunc(c), "height", true),
 		"block_by_hash":        rpcserver.NewRPCFunc(makeBlockByHashFunc(c), "hash", true),
 		"block_results":        rpcserver.NewRPCFunc(makeBlockResultsFunc(c), "height", true),
@@ -101,6 +103,22 @@ func makeGenesisChunkedFunc(c *lrpc.Client) rpcGenesisChunkedFunc {
 	}
 }
 
+type rpcHeaderFunc func(ctx *rpctypes.Context, height *int64) (*coretypes.ResultHeader, error)
+
+func makeHeaderFunc(c *lrpc.Client) rpcHeaderFunc {
+	return func(ctx *rpctypes.Context, height *int64) (*coretypes.ResultHeader, error) {
+		return c.Header(ctx.Context(), height)
+	}
+}
+
+type rpcHeaderByHashFunc func(ctx *rpctypes.Context, hash []byte) (*coretypes.ResultHeader, error)
+
+func makeHeaderByHashFunc(c *lrpc.Client) rpcHeaderByHashFunc {
+	return func(ctx *rpctypes.Context, hash []byte) (*coretypes.ResultHeader, error) {
+		return c.HeaderByHash(ctx.Context(), hash)
+	}
+}
+
 type rpcBlockFunc func(ctx *rpctypes.Context, height *int64) (*coretypes.ResultBlock, error)
 
 func makeBlockFunc(c *lrpc.Client) rpcBlockFunc {

light/rpc/client.go

@@ -451,6 +451,40 @@ func (c *Client) BlockResults(ctx context.Context, height *int64) (*coretypes.Re
 	return res, nil
 }
 
+// Header fetches and verifies the header directly via the light client
+func (c *Client) Header(ctx context.Context, height *int64) (*coretypes.ResultHeader, error) {
+	lb, err := c.updateLightClientIfNeededTo(ctx, height)
+	if err != nil {
+		return nil, err
+	}
+
+	return &coretypes.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) (*coretypes.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) (*coretypes.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.
@@ -535,7 +569,8 @@ func (c *Client) Validators(
 		BlockHeight: l.Height,
 		Validators:  v,
 		Count:       len(v),
-		Total:       totalCount}, nil
+		Total:       totalCount,
+	}, nil
 }
 
 func (c *Client) BroadcastEvidence(ctx context.Context, ev types.Evidence) (*coretypes.ResultBroadcastEvidence, error) {

rpc/client/http/http.go

@@ -92,9 +92,11 @@ 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
@@ -450,6 +452,31 @@ func (c *baseRPCClient) BlockResults(
 	return result, nil
 }
 
+func (c *baseRPCClient) Header(ctx context.Context, height *int64) (*coretypes.ResultHeader, error) {
+	result := new(coretypes.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) (*coretypes.ResultHeader, error) {
+	result := new(coretypes.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) (*coretypes.ResultCommit, error) {
 	result := new(coretypes.ResultCommit)
 	params := make(map[string]interface{})

rpc/client/interface.go

@@ -78,6 +78,8 @@ type SignClient interface {
 	Block(ctx context.Context, height *int64) (*coretypes.ResultBlock, error)
 	BlockByHash(ctx context.Context, hash bytes.HexBytes) (*coretypes.ResultBlock, error)
 	BlockResults(ctx context.Context, height *int64) (*coretypes.ResultBlockResults, error)
+	Header(ctx context.Context, height *int64) (*coretypes.ResultHeader, error)
+	HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*coretypes.ResultHeader, error)
 	Commit(ctx context.Context, height *int64) (*coretypes.ResultCommit, error)
 	Validators(ctx context.Context, height *int64, page, perPage *int) (*coretypes.ResultValidators, error)
 	Tx(ctx context.Context, hash bytes.HexBytes, prove bool) (*coretypes.ResultTx, error)

rpc/client/local/local.go

@@ -165,6 +165,14 @@ func (c *Local) BlockResults(ctx context.Context, height *int64) (*coretypes.Res
 	return c.env.BlockResults(c.ctx, height)
 }
 
+func (c *Local) Header(ctx context.Context, height *int64) (*coretypes.ResultHeader, error) {
+	return c.env.Header(c.ctx, height)
+}
+
+func (c *Local) HeaderByHash(ctx context.Context, hash bytes.HexBytes) (*coretypes.ResultHeader, error) {
+	return c.env.HeaderByHash(c.ctx, hash)
+}
+
 func (c *Local) Commit(ctx context.Context, height *int64) (*coretypes.ResultCommit, error) {
 	return c.env.Commit(c.ctx, height)
 }

rpc/client/mocks/client.go

@@ -457,6 +457,52 @@ 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) {
 	ret := _m.Called(_a0)

rpc/client/rpc_test.go

@@ -359,6 +359,15 @@ func TestClientMethodCalls(t *testing.T) {
 				require.NoError(t, err)
 				require.Equal(t, block, blockByHash)
 
+				// check that the header matches the block hash
+				header, err := c.Header(ctx, &apph)
+				require.NoError(t, err)
+				require.Equal(t, block.Block.Header, *header.Header)
+
+				headerByHash, err := c.HeaderByHash(ctx, block.BlockID.Hash)
+				require.NoError(t, err)
+				require.Equal(t, header, headerByHash)
+
 				// now check the results
 				blockResults, err := c.BlockResults(ctx, &txh)
 				require.NoError(t, err, "%d: %+v", i, err)
@@ -551,7 +560,6 @@ func TestClientMethodCalls(t *testing.T) {
 						_, err := c.BroadcastEvidence(ctx, fake)
 						require.Error(t, err, "BroadcastEvidence(%s) succeeded, but the evidence was fake", fake)
 					}
-
 				})
 				t.Run("BroadcastEmpty", func(t *testing.T) {
 					_, err := c.BroadcastEvidence(ctx, nil)
@@ -732,7 +740,6 @@ func TestClientMethodCallsAdvanced(t *testing.T) {
 
 		for _, c := range GetClients(t, n, conf) {
 			t.Run(fmt.Sprintf("%T", c), func(t *testing.T) {
-
 				// now we query for the tx.
 				result, err := c.TxSearch(ctx, fmt.Sprintf("tx.hash='%v'", find.Hash), true, nil, nil, "asc")
 				require.Nil(t, err)

rpc/coretypes/responses.go

@@ -51,6 +51,11 @@ 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

@@ -525,7 +525,7 @@ paths:
                 $ref: "#/components/schemas/ErrorResponse"
   /net_info:
     get:
-      summary: Network informations
+      summary: Network information
       operationId: net_info
       tags:
         - Info
@@ -693,6 +693,64 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/ErrorResponse"
+  /header:
+    get:
+      summary: Get the 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 height.
+      tags:
+        - Info
+      description: |
+        Retrieve the block header corresponding to a specified height.
+      responses:
+        "200":
+          description: Header information.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/HeaderResponse"
+        "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: |
+        Retrieve the block header corresponding to a block hash.
+      responses:
+        "200":
+          description: Header information.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/HeaderResponse"
+        "500":
+          description: Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorResponse"
   /block:
     get:
       summary: Get block at a specified height
@@ -711,7 +769,7 @@ paths:
         Get Block.
       responses:
         "200":
-          description: Block informations.
+          description: Block information.
           content:
             application/json:
               schema:
@@ -740,7 +798,7 @@ paths:
         Get Block By Hash.
       responses:
         "200":
-          description: Block informations.
+          description: Block information.
           content:
             application/json:
               schema:
@@ -758,7 +816,7 @@ paths:
       parameters:
         - in: query
           name: height
-          description: height to return. If no height is provided, it will fetch informations regarding the latest block.
+          description: height to return. If no height is provided, it will fetch information regarding the latest block.
           schema:
             type: integer
             default: 0
@@ -787,7 +845,7 @@ paths:
       parameters:
         - in: query
           name: height
-          description: height to return. If no height is provided, it will fetch commit informations regarding the latest block.
+          description: height to return. If no height is provided, it will fetch commit information regarding the latest block.
           schema:
             type: integer
             default: 0
@@ -968,7 +1026,7 @@ paths:
       parameters:
         - in: query
           name: height
-          description: height to return. If no height is provided, it will fetch commit informations regarding the latest block.
+          description: height to return. If no height is provided, it will fetch commit information regarding the latest block.
           schema:
             type: integer
             default: 0
@@ -1703,13 +1761,21 @@ components:
         block:
           $ref: "#/components/schemas/Block"
     BlockResponse:
-      description: Blockc info
+      description: Block info
       allOf:
         - $ref: "#/components/schemas/JSONRPC"
         - type: object
           properties:
             result:
               $ref: "#/components/schemas/BlockComplete"
+    HeaderResponse:
+      description: Block Header info
+      allOf:
+        - $ref: "#/components/schemas/JSONRPC"
+        - type: object
+          properties:
+            result:
+              $ref: "#/components/schemas/BlockHeader"
 
     ################## FROM NOW ON NEEDS REFACTOR ##################
     BlockResultsResponse: