Update rpc client header (#9276) (#9349) (#1096)

## Description

cherry picks the cherry pick to get the header back
d95e437

closes #1095

---------

Co-authored-by: Callum Waters <cmwaters19@gmail.com>
Co-authored-by: samricotta <37125168+samricotta@users.noreply.github.com>

consensus/replay_test.go

@@ -1211,7 +1211,7 @@ 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{

light/proxy/routes.go

@@ -28,6 +28,8 @@ func RPCRoutes(c *lrpc.Client) map[string]*rpcserver.RPCFunc {
 		"block_by_hash":        rpcserver.NewRPCFunc(makeBlockByHashFunc(c), "hash", rpcserver.Cacheable()),
 		"block_results":        rpcserver.NewRPCFunc(makeBlockResultsFunc(c), "height", rpcserver.Cacheable("height")),
 		"commit":               rpcserver.NewRPCFunc(makeCommitFunc(c), "height", rpcserver.Cacheable("height")),
+		"header":               rpcserver.NewRPCFunc(makeHeaderFunc(c), "height", rpcserver.Cacheable("height")),
+		"header_by_hash":       rpcserver.NewRPCFunc(makeHeaderByHashFunc(c), "hash"),
 		"tx":                   rpcserver.NewRPCFunc(makeTxFunc(c), "hash,prove", rpcserver.Cacheable()),
 		"tx_search":            rpcserver.NewRPCFunc(makeTxSearchFuncMatchEvents(c), "query,prove,page,per_page,order_by,match_events"),
 		"block_search":         rpcserver.NewRPCFunc(makeBlockSearchFuncMatchEvents(c), "query,page,per_page,order_by,match_events"),
@@ -109,6 +111,22 @@ 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

@@ -487,6 +487,40 @@ 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 cmtbytes.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
@@ -457,6 +459,31 @@ 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

@@ -68,6 +68,8 @@ type SignClient interface {
 	SignedBlock(ctx context.Context, height *int64) (*ctypes.ResultSignedBlock, 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)
 
 	DataCommitment(ctx context.Context, start, end uint64) (*ctypes.ResultDataCommitment, error)

rpc/client/local/local.go

@@ -173,6 +173,14 @@ 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/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

@@ -8,6 +8,7 @@ import (
 	"strconv"
 
 	"github.com/tendermint/tendermint/crypto/merkle"
+	"github.com/tendermint/tendermint/libs/bytes"
 	cmtmath "github.com/tendermint/tendermint/libs/math"
 	cmtquery "github.com/tendermint/tendermint/libs/pubsub/query"
 	"github.com/tendermint/tendermint/pkg/consts"
@@ -87,6 +88,38 @@ 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(GetEnvironment().BlockStore.Height(), heightPtr)
+	if err != nil {
+		return nil, err
+	}
+
+	blockMeta := GetEnvironment().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 := GetEnvironment().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.cometbft.com/v0.34/rpc/#/Info/block

rpc/core/blocks_test.go

@@ -13,13 +13,13 @@ import (
 	"github.com/tendermint/tendermint/crypto/merkle"
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 	cmtrand "github.com/tendermint/tendermint/libs/rand"
+	"github.com/tendermint/tendermint/types"
 
 	abci "github.com/tendermint/tendermint/abci/types"
 	cmtstate "github.com/tendermint/tendermint/proto/tendermint/state"
 	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"
 )
 
 func TestBlockchainInfo(t *testing.T) {
@@ -292,6 +292,7 @@ func (store mockBlockStore) Size() int64                                 { retur
 func (mockBlockStore) LoadBaseMeta() *types.BlockMeta                    { return nil }
 func (mockBlockStore) LoadBlockByHash(hash []byte) *types.Block          { return nil }
 func (mockBlockStore) LoadBlockPart(height int64, index int) *types.Part { return nil }
+func (mockBlockStore) LoadBlockMetaByHash(hash []byte) *types.BlockMeta  { 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 }

rpc/core/routes.go

@@ -25,6 +25,8 @@ var Routes = map[string]*rpc.RPCFunc{
 	"block_by_hash":             rpc.NewRPCFunc(BlockByHash, "hash", rpc.Cacheable()),
 	"block_results":             rpc.NewRPCFunc(BlockResults, "height", rpc.Cacheable("height")),
 	"commit":                    rpc.NewRPCFunc(Commit, "height", rpc.Cacheable("height")),
+	"header":                    rpc.NewRPCFunc(Header, "height", rpc.Cacheable("height")),
+	"header_by_hash":            rpc.NewRPCFunc(HeaderByHash, "hash"),
 	"data_commitment":           rpc.NewRPCFunc(DataCommitment, "start,end"),
 	"check_tx":                  rpc.NewRPCFunc(CheckTx, "tx"),
 	"tx":                        rpc.NewRPCFunc(Tx, "hash,prove", rpc.Cacheable()),

rpc/core/types/responses.go

@@ -49,6 +49,11 @@ type ResultSignedBlock struct {
 	ValidatorSet types.ValidatorSet `json:"validator_set"`
 }
 
+// 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

@@ -295,7 +295,7 @@ paths:
                 $ref: "#/components/schemas/ErrorResponse"
   /net_info:
     get:
-      summary: Network informations
+      summary: Network information
       operationId: net_info
       tags:
         - Info
@@ -439,6 +439,64 @@ 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