main: Add invalidateblock and reconsiderblock rpc commands

The rpc calls and the rpchelp is added for the invalidateblock
and reconsiderblock methods on BlockChain.

rpcclient/chain.go

@@ -1419,3 +1419,38 @@ func (c *Client) GetDescriptorInfoAsync(descriptor string) FutureGetDescriptorIn
 func (c *Client) GetDescriptorInfo(descriptor string) (*btcjson.GetDescriptorInfoResult, error) {
 	return c.GetDescriptorInfoAsync(descriptor).Receive()
 }
+
+// FutureReconsiderBlockResult is a future promise to deliver the result of a
+// ReconsiderBlockAsync RPC invocation (or an applicable error).
+type FutureReconsiderBlockResult chan *Response
+
+// Receive waits for the Response promised by the future and returns the raw
+// block requested from the server given its hash.
+func (r FutureReconsiderBlockResult) Receive() error {
+	_, err := ReceiveFuture(r)
+	return err
+}
+
+// ReconsiderBlockAsync returns an instance of a type that can be used to get the
+// result of the RPC at some future time by invoking the Receive function on the
+// returned instance.
+//
+// See ReconsiderBlock for the blocking version and more details.
+func (c *Client) ReconsiderBlockAsync(
+	blockHash *chainhash.Hash) FutureReconsiderBlockResult {
+
+	hash := ""
+	if blockHash != nil {
+		hash = blockHash.String()
+	}
+
+	cmd := btcjson.NewReconsiderBlockCmd(hash)
+	return c.SendCmd(cmd)
+}
+
+// ReconsiderBlock reconsiders an verifies a specific block and the branch that
+// the block is included in.  If the block is valid on reconsideration, the chain
+// will reorg to that block if it has more PoW than the current tip.
+func (c *Client) ReconsiderBlock(blockHash *chainhash.Hash) error {
+	return c.ReconsiderBlockAsync(blockHash).Receive()
+}

rpcserver.go

@@ -170,8 +170,10 @@ var rpcHandlersBeforeInit = map[string]commandHandler{
 	"getrawtransaction":      handleGetRawTransaction,
 	"gettxout":               handleGetTxOut,
 	"help":                   handleHelp,
+	"invalidateblock":        handleInvalidateBlock,
 	"node":                   handleNode,
 	"ping":                   handlePing,
+	"reconsiderblock":        handleReconsiderBlock,
 	"searchrawtransactions":  handleSearchRawTransactions,
 	"sendrawtransaction":     handleSendRawTransaction,
 	"setgenerate":            handleSetGenerate,
@@ -241,9 +243,7 @@ var rpcUnimplemented = map[string]struct{}{
 	"getmempoolentry":  {},
 	"getnetworkinfo":   {},
 	"getwork":          {},
-	"invalidateblock":  {},
 	"preciousblock":    {},
-	"reconsiderblock":  {},
 }
 
 // Commands that are available to a limited user
@@ -284,6 +284,8 @@ var rpcLimited = map[string]struct{}{
 	"getrawmempool":         {},
 	"getrawtransaction":     {},
 	"gettxout":              {},
+	"invalidateblock":       {},
+	"reconsiderblock":       {},
 	"searchrawtransactions": {},
 	"sendrawtransaction":    {},
 	"submitblock":           {},
@@ -2850,6 +2852,23 @@ func handleGetTxOut(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 	return txOutReply, nil
 }
 
+// handleInvalidateBlock implements the invalidateblock command.
+func handleInvalidateBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
+	c := cmd.(*btcjson.InvalidateBlockCmd)
+
+	invalidateHash, err := chainhash.NewHashFromStr(c.BlockHash)
+	if err != nil {
+		return nil, &btcjson.RPCError{
+			Code: btcjson.ErrRPCDeserialization,
+			Message: fmt.Sprintf("Failed to deserialize blockhash from string of %s",
+				invalidateHash),
+		}
+	}
+
+	err = s.cfg.Chain.InvalidateBlock(invalidateHash)
+	return nil, err
+}
+
 // handleHelp implements the help command.
 func handleHelp(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
 	c := cmd.(*btcjson.HelpCmd)
@@ -3123,6 +3142,23 @@ func fetchMempoolTxnsForAddress(s *rpcServer, addr btcutil.Address, numToSkip, n
 	return mpTxns[numToSkip:rangeEnd], numToSkip
 }
 
+// handleReconsiderBlock implements the reconsiderblock command.
+func handleReconsiderBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
+	c := cmd.(*btcjson.ReconsiderBlockCmd)
+
+	reconsiderHash, err := chainhash.NewHashFromStr(c.BlockHash)
+	if err != nil {
+		return nil, &btcjson.RPCError{
+			Code: btcjson.ErrRPCDeserialization,
+			Message: fmt.Sprintf("Failed to deserialize blockhash from string of %s",
+				reconsiderHash),
+		}
+	}
+
+	err = s.cfg.Chain.ReconsiderBlock(reconsiderHash)
+	return nil, err
+}
+
 // handleSearchRawTransactions implements the searchrawtransactions command.
 func handleSearchRawTransactions(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
 	// Respond with an error if the address index is not enabled.

rpcserverhelp.go

@@ -544,6 +544,10 @@ var helpDescsEnUS = map[string]string{
 	"gettxout-vout":           "The index of the output",
 	"gettxout-includemempool": "Include the mempool when true",
 
+	// InvalidateBlockCmd help.
+	"invalidateblock--synopsis": "Invalidates the block of the given block hash. To re-validate the invalidated block, use the reconsiderblock rpc",
+	"invalidateblock-blockhash": "The block hash of the block to invalidate",
+
 	// HelpCmd help.
 	"help--synopsis":   "Returns a list of all commands or help for a specified command.",
 	"help-command":     "The command to retrieve help for",
@@ -681,6 +685,10 @@ var helpDescsEnUS = map[string]string{
 	"loadtxfilter-addresses": "Array of addresses to add to the transaction filter",
 	"loadtxfilter-outpoints": "Array of outpoints to add to the transaction filter",
 
+	// ReconsiderBlockCmd help.
+	"reconsiderblock--synopsis": "Reconsiders the block of the given block hash. Can be used to re-validate blocks invalidated with invalidateblock",
+	"reconsiderblock-blockhash": "The block hash of the block to reconsider",
+
 	// Rescan help.
 	"rescan--synopsis": "Rescan block chain for transactions to addresses.\n" +
 		"When the endblock parameter is omitted, the rescan continues through the best block in the main chain.\n" +
@@ -788,7 +796,9 @@ var rpcResultTypes = map[string][]interface{}{
 	"gettxout":               {(*btcjson.GetTxOutResult)(nil)},
 	"node":                   nil,
 	"help":                   {(*string)(nil), (*string)(nil)},
+	"invalidateblock":        nil,
 	"ping":                   nil,
+	"reconsiderblock":        nil,
 	"searchrawtransactions":  {(*string)(nil), (*[]btcjson.SearchRawTransactionsResult)(nil)},
 	"sendrawtransaction":     {(*string)(nil)},
 	"setgenerate":            nil,