lnd.xprv/uspv/eight333.go
Tadge Dryja 4cd9087f9f problems with concurrent disk access (header file)
maybe add mutexes or something
2016-01-29 00:40:52 -08:00

513 lines
13 KiB
Go

package uspv
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"net"
"os"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil/bloom"
)
const (
keyFileName = "testseed.hex"
headerFileName = "headers.bin"
// Except hash-160s, those aren't backwards. But anything that's 32 bytes is.
// because, cmon, 32? Gotta reverse that. But 20? 20 is OK.
// version hardcoded for now, probably ok...?
VERSION = 70011
)
type SPVCon struct {
con net.Conn // the (probably tcp) connection to the node
headerFile *os.File // file for SPV headers
//[doesn't work without fancy mutexes, nevermind, just use header file]
// localHeight int32 // block height we're on
remoteHeight int32 // block height they're on
localVersion uint32 // version we report
remoteVersion uint32 // version remote node
// what's the point of the input queue? remove? leave for now...
inMsgQueue chan wire.Message // Messages coming in from remote node
outMsgQueue chan wire.Message // Messages going out to remote node
WBytes uint64 // total bytes written
RBytes uint64 // total bytes read
TS *TxStore // transaction store to write to
param *chaincfg.Params // network parameters (testnet3, testnetL)
// mBlockQueue is for keeping track of what height we've requested.
mBlockQueue chan HashAndHeight
// fPositives is a channel to keep track of bloom filter false positives.
fPositives chan int32
}
func OpenSPV(remoteNode string, hfn, tsfn string,
inTs *TxStore, p *chaincfg.Params) (SPVCon, error) {
// create new SPVCon
var s SPVCon
// assign network parameters to SPVCon
s.param = p
// open header file
err := s.openHeaderFile(headerFileName)
if err != nil {
return s, err
}
// open TCP connection
s.con, err = net.Dial("tcp", remoteNode)
if err != nil {
return s, err
}
// assign version bits for local node
s.localVersion = VERSION
// transaction store for this SPV connection
err = inTs.OpenDB(tsfn)
if err != nil {
return s, err
}
inTs.Param = p
s.TS = inTs // copy pointer of txstore into spvcon
myMsgVer, err := wire.NewMsgVersionFromConn(s.con, 0, 0)
if err != nil {
return s, err
}
err = myMsgVer.AddUserAgent("test", "zero")
if err != nil {
return s, err
}
// must set this to enable SPV stuff
myMsgVer.AddService(wire.SFNodeBloom)
// this actually sends
n, err := wire.WriteMessageN(s.con, myMsgVer, s.localVersion, s.param.Net)
if err != nil {
return s, err
}
s.WBytes += uint64(n)
log.Printf("wrote %d byte version message to %s\n",
n, s.con.RemoteAddr().String())
n, m, b, err := wire.ReadMessageN(s.con, s.localVersion, s.param.Net)
if err != nil {
return s, err
}
s.RBytes += uint64(n)
log.Printf("got %d byte response %x\n command: %s\n", n, b, m.Command())
mv, ok := m.(*wire.MsgVersion)
if ok {
log.Printf("connected to %s", mv.UserAgent)
}
log.Printf("remote reports version %x (dec %d)\n",
mv.ProtocolVersion, mv.ProtocolVersion)
// set remote height
s.remoteHeight = mv.LastBlock
mva := wire.NewMsgVerAck()
n, err = wire.WriteMessageN(s.con, mva, s.localVersion, s.param.Net)
if err != nil {
return s, err
}
s.WBytes += uint64(n)
s.inMsgQueue = make(chan wire.Message)
go s.incomingMessageHandler()
s.outMsgQueue = make(chan wire.Message)
go s.outgoingMessageHandler()
s.mBlockQueue = make(chan HashAndHeight, 32) // queue depth 32 is a thing
s.fPositives = make(chan int32, 4000) // a block full, approx
go s.fPositiveHandler()
return s, nil
}
func (s *SPVCon) openHeaderFile(hfn string) error {
_, err := os.Stat(hfn)
if err != nil {
if os.IsNotExist(err) {
var b bytes.Buffer
err = s.param.GenesisBlock.Header.Serialize(&b)
if err != nil {
return err
}
err = ioutil.WriteFile(hfn, b.Bytes(), 0600)
if err != nil {
return err
}
log.Printf("created hardcoded genesis header at %s\n",
hfn)
}
}
s.headerFile, err = os.OpenFile(hfn, os.O_RDWR, 0600)
if err != nil {
return err
}
log.Printf("opened header file %s\n", s.headerFile.Name())
return nil
}
func (s *SPVCon) PongBack(nonce uint64) {
mpong := wire.NewMsgPong(nonce)
s.outMsgQueue <- mpong
return
}
func (s *SPVCon) SendFilter(f *bloom.Filter) {
s.outMsgQueue <- f.MsgFilterLoad()
return
}
// HeightFromHeader gives you the block height given a 80 byte block header
// seems like looking for the merkle root is the best way to do this
func (s *SPVCon) HeightFromHeader(query wire.BlockHeader) (uint32, error) {
// start from the most recent and work back in time; even though that's
// kind of annoying it's probably a lot faster since things tend to have
// happened recently.
// seek to last header
lastPos, err := s.headerFile.Seek(-80, os.SEEK_END)
if err != nil {
return 0, err
}
height := lastPos / 80
var current wire.BlockHeader
for height > 0 {
// grab header from disk
err = current.Deserialize(s.headerFile)
if err != nil {
return 0, err
}
// check if merkle roots match
if current.MerkleRoot.IsEqual(&query.MerkleRoot) {
// if they do, great, return height
return uint32(height), nil
}
// skip back one header (2 because we just read one)
_, err = s.headerFile.Seek(-160, os.SEEK_CUR)
if err != nil {
return 0, err
}
// decrement height
height--
}
// finished for loop without finding match
return 0, fmt.Errorf("Header not found on disk")
}
// AskForTx requests a tx we heard about from an inv message.
// It's one at a time but should be fast enough.
func (s *SPVCon) AskForTx(txid wire.ShaHash) {
gdata := wire.NewMsgGetData()
inv := wire.NewInvVect(wire.InvTypeTx, &txid)
gdata.AddInvVect(inv)
s.outMsgQueue <- gdata
}
// AskForBlock requests a merkle block we heard about from an inv message.
// We don't have it in our header file so when we get it we do both operations:
// appending and checking the header, and checking spv proofs
func (s *SPVCon) AskForBlock(hsh wire.ShaHash) {
gdata := wire.NewMsgGetData()
inv := wire.NewInvVect(wire.InvTypeFilteredBlock, &hsh)
gdata.AddInvVect(inv)
info, err := s.headerFile.Stat() // get
if err != nil {
log.Fatal(err) // crash if header file disappears
}
nextHeight := int32(info.Size() / 80)
hah := NewRootAndHeight(hsh, nextHeight)
fmt.Printf("AskForBlock - %s height %d\n", hsh.String(), nextHeight)
s.mBlockQueue <- hah // push height and mroot of requested block on queue
s.outMsgQueue <- gdata // push request to outbox
}
func (s *SPVCon) AskForHeaders() error {
var hdr wire.BlockHeader
ghdr := wire.NewMsgGetHeaders()
ghdr.ProtocolVersion = s.localVersion
info, err := s.headerFile.Stat()
if err != nil {
return err
}
headerFileSize := info.Size()
if headerFileSize == 0 || headerFileSize%80 != 0 { // header file broken
return fmt.Errorf("Header file not a multiple of 80 bytes")
}
// seek to 80 bytes from end of file
ns, err := s.headerFile.Seek(-80, os.SEEK_END)
if err != nil {
log.Printf("can't seek\n")
return err
}
log.Printf("suk to offset %d (should be near the end\n", ns)
// get header from last 80 bytes of file
err = hdr.Deserialize(s.headerFile)
if err != nil {
log.Printf("can't Deserialize")
return err
}
cHash := hdr.BlockSha()
err = ghdr.AddBlockLocatorHash(&cHash)
if err != nil {
return err
}
fmt.Printf("get headers message has %d header hashes, first one is %s\n",
len(ghdr.BlockLocatorHashes), ghdr.BlockLocatorHashes[0].String())
s.outMsgQueue <- ghdr
return nil
}
func (s *SPVCon) IngestMerkleBlock(m *wire.MsgMerkleBlock) error {
txids, err := checkMBlock(m) // check self-consistency
if err != nil {
return err
}
hah := <-s.mBlockQueue // pop height off mblock queue
// this verifies order, and also that the returned header fits
// into our SPV header file
newMerkBlockSha := m.Header.BlockSha()
if !hah.blockhash.IsEqual(&newMerkBlockSha) {
return fmt.Errorf("merkle block out of order error")
}
for _, txid := range txids {
err := s.TS.AddTxid(txid, hah.height)
if err != nil {
return fmt.Errorf("Txid store error: %s\n", err.Error())
}
}
err = s.TS.SetDBSyncHeight(hah.height)
if err != nil {
return err
}
return nil
}
// IngestHeaders takes in a bunch of headers and appends them to the
// local header file, checking that they fit. If there's no headers,
// it assumes we're done and returns false. If it worked it assumes there's
// more to request and returns true.
func (s *SPVCon) IngestHeaders(m *wire.MsgHeaders) (bool, error) {
var err error
// seek to last header
_, err = s.headerFile.Seek(-80, os.SEEK_END)
if err != nil {
return false, err
}
var last wire.BlockHeader
err = last.Deserialize(s.headerFile)
if err != nil {
return false, err
}
prevHash := last.BlockSha()
endPos, err := s.headerFile.Seek(0, os.SEEK_END)
if err != nil {
return false, err
}
tip := int32(endPos/80) - 1 // move back 1 header length to read
gotNum := int64(len(m.Headers))
if gotNum > 0 {
fmt.Printf("got %d headers. Range:\n%s - %s\n",
gotNum, m.Headers[0].BlockSha().String(),
m.Headers[len(m.Headers)-1].BlockSha().String())
} else {
log.Printf("got 0 headers, we're probably synced up")
return false, nil
}
// check first header returned to make sure it fits on the end
// of our header file
if !m.Headers[0].PrevBlock.IsEqual(&prevHash) {
// delete 100 headers if this happens! Dumb reorg.
log.Printf("reorg? header msg doesn't fit. points to %s, expect %s",
m.Headers[0].PrevBlock.String(), prevHash.String())
if endPos < 8080 {
// jeez I give up, back to genesis
s.headerFile.Truncate(80)
} else {
err = s.headerFile.Truncate(endPos - 8000)
if err != nil {
return false, fmt.Errorf("couldn't truncate header file")
}
}
return true, fmt.Errorf("Truncated header file to try again")
}
for _, resphdr := range m.Headers {
// write to end of file
err = resphdr.Serialize(s.headerFile)
if err != nil {
return false, err
}
// advance chain tip
tip++
// check last header
worked := CheckHeader(s.headerFile, tip, s.param)
if !worked {
if endPos < 8080 {
// jeez I give up, back to genesis
s.headerFile.Truncate(80)
} else {
err = s.headerFile.Truncate(endPos - 8000)
if err != nil {
return false, fmt.Errorf("couldn't truncate header file")
}
}
// probably should disconnect from spv node at this point,
// since they're giving us invalid headers.
return false, fmt.Errorf(
"Header %d - %s doesn't fit, dropping 100 headers.",
resphdr.BlockSha().String(), tip)
}
}
log.Printf("Headers to height %d OK.", tip)
return true, nil
}
// HashAndHeight is needed instead of just height in case a fullnode
// responds abnormally (?) by sending out of order merkleblocks.
// we cache a merkleroot:height pair in the queue so we don't have to
// look them up from the disk.
// Also used when inv messages indicate blocks so we can add the header
// and parse the txs in one request instead of requesting headers first.
type HashAndHeight struct {
blockhash wire.ShaHash
height int32
}
// NewRootAndHeight saves like 2 lines.
func NewRootAndHeight(b wire.ShaHash, h int32) (hah HashAndHeight) {
hah.blockhash = b
hah.height = h
return
}
func (s *SPVCon) PushTx(tx *wire.MsgTx) error {
txid := tx.TxSha()
err := s.TS.AddTxid(&txid, 0)
if err != nil {
return err
}
_, err = s.TS.AckTx(tx) // our own tx so don't need to track relevance
if err != nil {
return err
}
s.outMsgQueue <- tx
return nil
}
func (s *SPVCon) GetNextHeaderHeight() (int32, error) {
info, err := s.headerFile.Stat() // get
if err != nil {
return 0, err // crash if header file disappears
}
nextHeight := int32(info.Size() / 80)
return nextHeight, nil
}
func (s *SPVCon) RemoveHeaders(r int32) error {
endPos, err := s.headerFile.Seek(0, os.SEEK_END)
if err != nil {
return err
}
err = s.headerFile.Truncate(endPos - int64(r*80))
if err != nil {
return fmt.Errorf("couldn't truncate header file")
}
return nil
}
// AskForMerkBlocks requests blocks from current to last
// right now this asks for 1 block per getData message.
// Maybe it's faster to ask for many in a each message?
func (s *SPVCon) AskForMerkBlocks(current, last int32) error {
var hdr wire.BlockHeader
nextHeight, err := s.GetNextHeaderHeight()
if err != nil {
return err
}
fmt.Printf("have headers up to height %d\n", nextHeight-1)
// if last is 0, that means go as far as we can
if last < current {
return fmt.Errorf("MBlock range %d < %d\n", last, current)
}
fmt.Printf("will request merkleblocks %d to %d\n", current, last)
// create initial filter
filt, err := s.TS.GimmeFilter()
if err != nil {
return err
}
// send filter
s.SendFilter(filt)
fmt.Printf("sent filter %x\n", filt.MsgFilterLoad().Filter)
_, err = s.headerFile.Seek(int64((current-1)*80), os.SEEK_SET)
if err != nil {
return err
}
// loop through all heights where we want merkleblocks.
for current <= last {
// load header from file
err = hdr.Deserialize(s.headerFile)
if err != nil {
log.Printf("Deserialize err\n")
return err
}
bHash := hdr.BlockSha()
// create inventory we're asking for
iv1 := wire.NewInvVect(wire.InvTypeFilteredBlock, &bHash)
gdataMsg := wire.NewMsgGetData()
// add inventory
err = gdataMsg.AddInvVect(iv1)
if err != nil {
return err
}
hah := NewRootAndHeight(hdr.BlockSha(), current)
s.outMsgQueue <- gdataMsg
s.mBlockQueue <- hah // push height and mroot of requested block on queue
current++
}
// done syncing blocks known in header file, ask for new headers we missed
// s.AskForHeaders()
// don't need this -- will sync to end regardless
return nil
}