// Receive waits for the response promised by the future and returns the raw
// block requested from the server given its hash.
func (r FutureGetBlockResult) Receive() (*wire.MsgBlock, error) {
res, err := receiveFuture(r)
if err != nil {
return nil, err
}
// Unmarshal result as a string.
var blockHex string
err = json.Unmarshal(res, &blockHex)
if err != nil {
return nil, err
}
// Decode the serialized block hex to raw bytes.
serializedBlock, err := hex.DecodeString(blockHex)
if err != nil {
return nil, err
}
// Deserialize the block and return it.
var msgBlock wire.MsgBlock
err = msgBlock.Deserialize(bytes.NewReader(serializedBlock))
if err != nil {
return nil, err
}
return &msgBlock, nil
}
// TestBlockSerializeErrors performs negative tests against wire encode and
// decode of MsgBlock to confirm error paths work correctly.
func TestBlockSerializeErrors(t *testing.T) {
tests := []struct {
in *wire.MsgBlock // Value to encode
buf []byte // Serialized data
max int // Max size of fixed buffer to induce errors
writeErr error // Expected write error
readErr error // Expected read error
}{
// Force error in version.
{&blockOne, blockOneBytes, 0, io.ErrShortWrite, io.EOF},
// Force error in prev block hash.
{&blockOne, blockOneBytes, 4, io.ErrShortWrite, io.EOF},
// Force error in merkle root.
{&blockOne, blockOneBytes, 36, io.ErrShortWrite, io.EOF},
// Force error in timestamp.
{&blockOne, blockOneBytes, 68, io.ErrShortWrite, io.EOF},
// Force error in difficulty bits.
{&blockOne, blockOneBytes, 72, io.ErrShortWrite, io.EOF},
// Force error in header nonce.
{&blockOne, blockOneBytes, 76, io.ErrShortWrite, io.EOF},
// Force error in transaction count.
{&blockOne, blockOneBytes, 80, io.ErrShortWrite, io.EOF},
// Force error in transactions.
{&blockOne, blockOneBytes, 81, io.ErrShortWrite, io.EOF},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Serialize the block.
w := newFixedWriter(test.max)
err := test.in.Serialize(w)
if err != test.writeErr {
t.Errorf("Serialize #%d wrong error got: %v, want: %v",
i, err, test.writeErr)
continue
}
// Deserialize the block.
var block wire.MsgBlock
r := newFixedReader(test.max, test.buf)
err = block.Deserialize(r)
if err != test.readErr {
t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
var txLocBlock wire.MsgBlock
br := bytes.NewBuffer(test.buf[0:test.max])
_, err = txLocBlock.DeserializeTxLoc(br)
if err != test.readErr {
t.Errorf("DeserializeTxLoc #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
}
}
// NewBlockFromReader returns a new instance of a bitcoin block given a
// Reader to deserialize the block. See Block.
func NewBlockFromReader(r io.Reader) (*Block, error) {
// Deserialize the bytes into a MsgBlock.
var msgBlock wire.MsgBlock
err := msgBlock.Deserialize(r)
if err != nil {
return nil, err
}
b := Block{
msgBlock: &msgBlock,
blockHeight: BlockHeightUnknown,
}
return &b, nil
}
// initChainState attempts to load and initialize the chain state from the
// database. When the db does not yet contain any chain state, both it and the
// chain state are initialized to the genesis block.
func (b *BlockChain) initChainState() error {
// Attempt to load the chain state from the database.
var isStateInitialized bool
err := b.db.View(func(dbTx database.Tx) error {
// Fetch the stored chain state from the database metadata.
// When it doesn't exist, it means the database hasn't been
// initialized for use with chain yet, so break out now to allow
// that to happen under a writable database transaction.
serializedData := dbTx.Metadata().Get(chainStateKeyName)
if serializedData == nil {
return nil
}
log.Tracef("Serialized chain state: %x", serializedData)
state, err := deserializeBestChainState(serializedData)
if err != nil {
return err
}
// Load the raw block bytes for the best block.
blockBytes, err := dbTx.FetchBlock(&state.hash)
if err != nil {
return err
}
var block wire.MsgBlock
err = block.Deserialize(bytes.NewReader(blockBytes))
if err != nil {
return err
}
// Create a new node and set it as the best node. The preceding
// nodes will be loaded on demand as needed.
header := &block.Header
node := newBlockNode(header, &state.hash, int32(state.height))
node.inMainChain = true
node.workSum = state.workSum
b.bestNode = node
// Add the new node to the indices for faster lookups.
prevHash := node.parentHash
b.index[*node.hash] = node
b.depNodes[*prevHash] = append(b.depNodes[*prevHash], node)
// Initialize the state related to the best block.
blockSize := uint64(len(blockBytes))
numTxns := uint64(len(block.Transactions))
b.stateSnapshot = newBestState(b.bestNode, blockSize, numTxns,
state.totalTxns)
isStateInitialized = true
return nil
})
if err != nil {
return err
}
// There is nothing more to do if the chain state was initialized.
if isStateInitialized {
return nil
}
// At this point the database has not already been initialized, so
// initialize both it and the chain state to the genesis block.
return b.createChainState()
}
// TestBlockOverflowErrors performs tests to ensure deserializing blocks which
// are intentionally crafted to use large values for the number of transactions
// are handled properly. This could otherwise potentially be used as an attack
// vector.
func TestBlockOverflowErrors(t *testing.T) {
// Use protocol version 70001 specifically here instead of the latest
// protocol version because the test data is using bytes encoded with
// that version.
pver := uint32(70001)
tests := []struct {
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
err error // Expected error
}{
// Block that claims to have ~uint64(0) transactions.
{
[]byte{
0x01, 0x00, 0x00, 0x00, // Version 1
0x6f, 0xe2, 0x8c, 0x0a, 0xb6, 0xf1, 0xb3, 0x72,
0xc1, 0xa6, 0xa2, 0x46, 0xae, 0x63, 0xf7, 0x4f,
0x93, 0x1e, 0x83, 0x65, 0xe1, 0x5a, 0x08, 0x9c,
0x68, 0xd6, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00, // PrevBlock
0x98, 0x20, 0x51, 0xfd, 0x1e, 0x4b, 0xa7, 0x44,
0xbb, 0xbe, 0x68, 0x0e, 0x1f, 0xee, 0x14, 0x67,
0x7b, 0xa1, 0xa3, 0xc3, 0x54, 0x0b, 0xf7, 0xb1,
0xcd, 0xb6, 0x06, 0xe8, 0x57, 0x23, 0x3e, 0x0e, // MerkleRoot
0x61, 0xbc, 0x66, 0x49, // Timestamp
0xff, 0xff, 0x00, 0x1d, // Bits
0x01, 0xe3, 0x62, 0x99, // Nonce
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, // TxnCount
}, pver, &wire.MessageError{},
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Decode from wire format.
var msg wire.MsgBlock
r := bytes.NewReader(test.buf)
err := msg.BtcDecode(r, test.pver)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
i, err, reflect.TypeOf(test.err))
continue
}
// Deserialize from wire format.
r = bytes.NewReader(test.buf)
err = msg.Deserialize(r)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
i, err, reflect.TypeOf(test.err))
continue
}
// Deserialize with transaction location info from wire format.
br := bytes.NewBuffer(test.buf)
_, err = msg.DeserializeTxLoc(br)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("DeserializeTxLoc #%d wrong error got: %v, "+
"want: %v", i, err, reflect.TypeOf(test.err))
continue
}
}
}
// TestBlockSerialize tests MsgBlock serialize and deserialize.
func TestBlockSerialize(t *testing.T) {
tests := []struct {
in *wire.MsgBlock // Message to encode
out *wire.MsgBlock // Expected decoded message
buf []byte // Serialized data
txLocs []wire.TxLoc // Expected transaction locations
}{
{
&blockOne,
&blockOne,
blockOneBytes,
blockOneTxLocs,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Serialize the block.
var buf bytes.Buffer
err := test.in.Serialize(&buf)
if err != nil {
t.Errorf("Serialize #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("Serialize #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
// Deserialize the block.
var block wire.MsgBlock
rbuf := bytes.NewReader(test.buf)
err = block.Deserialize(rbuf)
if err != nil {
t.Errorf("Deserialize #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&block, test.out) {
t.Errorf("Deserialize #%d\n got: %s want: %s", i,
spew.Sdump(&block), spew.Sdump(test.out))
continue
}
// Deserialize the block while gathering transaction location
// information.
var txLocBlock wire.MsgBlock
br := bytes.NewBuffer(test.buf)
txLocs, err := txLocBlock.DeserializeTxLoc(br)
if err != nil {
t.Errorf("DeserializeTxLoc #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&txLocBlock, test.out) {
t.Errorf("DeserializeTxLoc #%d\n got: %s want: %s", i,
spew.Sdump(&txLocBlock), spew.Sdump(test.out))
continue
}
if !reflect.DeepEqual(txLocs, test.txLocs) {
t.Errorf("DeserializeTxLoc #%d\n got: %s want: %s", i,
spew.Sdump(txLocs), spew.Sdump(test.txLocs))
continue
}
}
}