lightwalletd/common/darkside.go

259 lines
7.1 KiB
Go

package common
import (
"bufio"
"encoding/hex"
"encoding/json"
"errors"
"io"
"io/ioutil"
"os"
"os/exec"
"strconv"
"strings"
"time"
"github.com/zcash/lightwalletd/parser"
)
type darksideState struct {
startHeight int
saplingActivation int
branchID string
chainName string
// Should always be nonempty. Index 0 is the block at height start_height.
blocks [][]byte // full blocks, binary, as from zcashd getblock rpc
incomingTransactions [][]byte // full transactions, binary, zcashd getrawtransaction txid
serverStart time.Time
}
var state darksideState
func DarksideIsEnabled() bool {
return state.chainName != ""
}
func DarksideInit() {
state = darksideState{
startHeight: -1,
saplingActivation: -1,
branchID: "2bb40e60", // Blossom
chainName: "darkside",
blocks: make([][]byte, 0),
incomingTransactions: make([][]byte, 0),
serverStart: time.Now(),
}
RawRequest = darksideRawRequest
f := "testdata/darkside/init-blocks"
testBlocks, err := os.Open(f)
if err != nil {
Log.Warn("Error opening default darksidewalletd blocks file", f)
return
}
if err = readBlocks(testBlocks); err != nil {
Log.Warn("Error loading default darksidewalletd blocks")
}
}
// DarksideAddBlock adds a single block to the blocks list.
func DarksideAddBlock(blockHex string) error {
if blockHex == "404: Not Found" {
// special case error (http resource not found, bad pathname)
return errors.New(blockHex)
}
blockData, err := hex.DecodeString(blockHex)
if err != nil {
return err
}
block := parser.NewBlock()
rest, err := block.ParseFromSlice(blockData)
if err != nil {
return err
}
if len(rest) != 0 {
return errors.New("block serialization is too long")
}
blockHeight := block.GetHeight()
// first block, add to existing blocks slice if possible
if blockHeight > state.startHeight+len(state.blocks) {
// The new block can't contiguously extend the existing
// range, so we have to drop the existing range.
state.blocks = state.blocks[:0]
} else if blockHeight < state.startHeight {
// This block will replace the entire existing range.
state.blocks = state.blocks[:0]
} else {
// Drop the block that will be overwritten, and its children.
state.blocks = state.blocks[:blockHeight-state.startHeight]
}
if len(state.blocks) == 0 {
state.startHeight = blockHeight
} else {
// Set this block's prevhash.
prevblock := parser.NewBlock()
rest, err := prevblock.ParseFromSlice(state.blocks[len(state.blocks)-1])
if err != nil {
return err
}
if len(rest) != 0 {
return errors.New("block is too long")
}
copy(blockData[4:4+32], prevblock.GetEncodableHash())
}
if state.saplingActivation < 0 {
state.saplingActivation = blockHeight
}
state.blocks = append(state.blocks, blockData)
return nil
}
func readBlocks(src io.Reader) error {
// some blocks are too large, especially when encoded in hex, for the
// default buffer size, so set up a larger one; 8mb should be enough.
scan := bufio.NewScanner(src)
var scanbuf []byte
scan.Buffer(scanbuf, 8*1000*1000)
for scan.Scan() { // each line (block)
if err := DarksideAddBlock(scan.Text()); err != nil {
return err
}
}
if scan.Err() != nil {
return scan.Err()
}
return nil
}
func DarksideSetMetaState(sa int32, bi, cn string) error {
state.saplingActivation = int(sa)
state.branchID = bi
state.chainName = cn
return nil
}
func DarksideGetIncomingTransactions() [][]byte {
return state.incomingTransactions
}
func DarksideSetBlocksURL(url string) error {
if strings.HasPrefix(url, "file:") && len(url) >= 6 && url[5] != '/' {
dir, err := os.Getwd()
if err != nil {
return err
}
url = "file:" + dir + string(os.PathSeparator) + url[5:]
}
cmd := exec.Command("curl", "--silent", "--show-error", url)
stdout, err := cmd.StdoutPipe()
if err != nil {
return err
}
stderr, err := cmd.StderrPipe()
if err != nil {
return err
}
if err := cmd.Start(); err != nil {
return err
}
defer cmd.Wait()
err = readBlocks(stdout)
if err != nil {
return err
}
stderroutstr, err := ioutil.ReadAll(stderr)
if err != nil {
return err
}
if len(stderroutstr) > 0 {
return errors.New(string(stderroutstr))
}
return nil
}
func DarksideSendTransaction(txbytes []byte) {
state.incomingTransactions = append(state.incomingTransactions, txbytes)
}
func darksideRawRequest(method string, params []json.RawMessage) (json.RawMessage, error) {
if time.Now().Sub(state.serverStart).Minutes() >= 30 {
Log.Fatal("Shutting down darksidewalletd to prevent accidental deployment in production.")
}
switch method {
case "getblockchaininfo":
type upgradeinfo struct {
// there are other fields that aren't needed here, omit them
ActivationHeight int `json:"activationheight"`
}
type consensus struct {
Nextblock string `json:"nextblock"`
Chaintip string `json:"chaintip"`
}
blockchaininfo := struct {
Chain string `json:"chain"`
Upgrades map[string]upgradeinfo `json:"upgrades"`
Headers int `json:"headers"`
Consensus consensus `json:"consensus"`
}{
Chain: state.chainName,
Upgrades: map[string]upgradeinfo{
"76b809bb": {ActivationHeight: state.saplingActivation},
},
Headers: state.startHeight + len(state.blocks) - 1,
Consensus: consensus{state.branchID, state.branchID},
}
return json.Marshal(blockchaininfo)
case "getblock":
var heightStr string
err := json.Unmarshal(params[0], &heightStr)
if err != nil {
return nil, errors.New("failed to parse getblock request")
}
height, err := strconv.Atoi(heightStr)
if err != nil {
return nil, errors.New("error parsing height as integer")
}
index := height - state.startHeight
const notFoundErr = "-8:"
if state.saplingActivation < 0 || index == len(state.blocks) {
// The current ingestor keeps going until it sees this error,
// meaning it's up to the latest height.
return nil, errors.New(notFoundErr)
}
if index < 0 || index > len(state.blocks) {
// If an integration test can reach this, it could be a bug, so generate an error.
Log.Errorf("getblock request made for out-of-range height %d (have %d to %d)",
height, state.startHeight, state.startHeight+len(state.blocks)-1)
return nil, errors.New(notFoundErr)
}
return []byte("\"" + hex.EncodeToString(state.blocks[index]) + "\""), nil
case "getaddresstxids":
// Not required for minimal reorg testing.
return nil, errors.New("not implemented yet")
case "getrawtransaction":
// Not required for minimal reorg testing.
return nil, errors.New("not implemented yet")
case "sendrawtransaction":
var rawtx string
err := json.Unmarshal(params[0], &rawtx)
if err != nil {
return nil, errors.New("failed to parse sendrawtransaction JSON")
}
txbytes, err := hex.DecodeString(rawtx)
if err != nil {
return nil, errors.New("failed to parse sendrawtransaction value as a hex string")
}
state.incomingTransactions = append(state.incomingTransactions, txbytes)
return nil, nil
default:
return nil, errors.New("there was an attempt to call an unsupported RPC")
}
}