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server.go
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server.go
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// Copyright (c) 2013-2017 The btcsuite developers
// Copyright (c) 2015-2018 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package main
import (
"bytes"
"crypto/rand"
"crypto/tls"
"encoding/binary"
"errors"
"fmt"
"math"
"net"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"github.com/gcash/bchd/addrmgr"
"github.com/gcash/bchd/blockchain"
"github.com/gcash/bchd/blockchain/indexers"
"github.com/gcash/bchd/chaincfg"
"github.com/gcash/bchd/chaincfg/chainhash"
"github.com/gcash/bchd/connmgr"
"github.com/gcash/bchd/database"
"github.com/gcash/bchd/mempool"
"github.com/gcash/bchd/mining"
"github.com/gcash/bchd/mining/cpuminer"
"github.com/gcash/bchd/netsync"
"github.com/gcash/bchd/peer"
"github.com/gcash/bchd/txscript"
"github.com/gcash/bchd/version"
"github.com/gcash/bchd/wire"
"github.com/gcash/bchutil"
"github.com/gcash/bchutil/bloom"
)
const (
// defaultServices describes the default services that are supported by
// the server.
defaultServices = wire.SFNodeNetwork | wire.SFNodeBloom |
wire.SFNodeCF | wire.SFNodeBitcoinCash
// defaultRequiredServices describes the default services that are
// required to be supported by outbound peers.
defaultRequiredServices = wire.SFNodeNetwork
// connectionRetryInterval is the base amount of time to wait in between
// retries when connecting to persistent peers. It is adjusted by the
// number of retries such that there is a retry backoff.
connectionRetryInterval = time.Second * 5
)
var (
// userAgentName is the user agent name and is used to help identify
// ourselves to other bitcoin peers.
userAgentName = "/bchd"
// userAgentVersion is the user agent version and is used to help
// identify ourselves to other bitcoin peers.
userAgentVersion = fmt.Sprintf("%d.%d.%d", version.AppMajor, version.AppMinor, version.AppPatch)
)
// addrMe specifies the server address to send peers.
var addrMe *wire.NetAddress
// zeroHash is the zero value hash (all zeros). It is defined as a convenience.
var zeroHash chainhash.Hash
// onionAddr implements the net.Addr interface and represents a tor address.
type onionAddr struct {
addr string
}
// String returns the onion address.
//
// This is part of the net.Addr interface.
func (oa *onionAddr) String() string {
return oa.addr
}
// Network returns "onion".
//
// This is part of the net.Addr interface.
func (oa *onionAddr) Network() string {
return "onion"
}
// Ensure onionAddr implements the net.Addr interface.
var _ net.Addr = (*onionAddr)(nil)
// simpleAddr implements the net.Addr interface with two struct fields
type simpleAddr struct {
net, addr string
}
// String returns the address.
//
// This is part of the net.Addr interface.
func (a simpleAddr) String() string {
return a.addr
}
// Network returns the network.
//
// This is part of the net.Addr interface.
func (a simpleAddr) Network() string {
return a.net
}
// Ensure simpleAddr implements the net.Addr interface.
var _ net.Addr = simpleAddr{}
// broadcastMsg provides the ability to house a bitcoin message to be broadcast
// to all connected peers except specified excluded peers.
type broadcastMsg struct {
message wire.Message
excludePeers []*serverPeer
}
// broadcastInventoryAdd is a type used to declare that the InvVect it contains
// needs to be added to the rebroadcast map
type broadcastInventoryAdd relayMsg
// broadcastInventoryDel is a type used to declare that the InvVect it contains
// needs to be removed from the rebroadcast map
type broadcastInventoryDel *wire.InvVect
// relayMsg packages an inventory vector along with the newly discovered
// inventory so the relay has access to that information.
type relayMsg struct {
invVect *wire.InvVect
data interface{}
}
// updatePeerHeightsMsg is a message sent from the blockmanager to the server
// after a new block has been accepted. The purpose of the message is to update
// the heights of peers that were known to announce the block before we
// connected it to the main chain or recognized it as an orphan. With these
// updates, peer heights will be kept up to date, allowing for fresh data when
// selecting sync peer candidacy.
type updatePeerHeightsMsg struct {
newHash *chainhash.Hash
newHeight int32
originPeer *peer.Peer
}
// peerState maintains state of inbound, persistent, outbound peers as well
// as banned peers and outbound groups.
type peerState struct {
inboundPeers map[int32]*serverPeer
outboundPeers map[int32]*serverPeer
persistentPeers map[int32]*serverPeer
banned map[string]time.Time
outboundGroups map[string]int
connectionCount map[string]int
}
// Count returns the count of all known peers.
func (ps *peerState) Count() int {
return len(ps.inboundPeers) + len(ps.outboundPeers) +
len(ps.persistentPeers)
}
// CountIP returns the count of all peers matching the IP.
func (ps *peerState) CountIP(host string) int {
return ps.connectionCount[host]
}
// forAllOutboundPeers is a helper function that runs closure on all outbound
// peers known to peerState.
func (ps *peerState) forAllOutboundPeers(closure func(sp *serverPeer)) {
for _, e := range ps.outboundPeers {
closure(e)
}
for _, e := range ps.persistentPeers {
closure(e)
}
}
// forAllPeers is a helper function that runs closure on all peers known to
// peerState.
func (ps *peerState) forAllPeers(closure func(sp *serverPeer)) {
for _, e := range ps.inboundPeers {
closure(e)
}
ps.forAllOutboundPeers(closure)
}
// cfHeaderKV is a tuple of a filter header and its associated block hash. The
// struct is used to cache cfcheckpt responses.
type cfHeaderKV struct {
blockHash chainhash.Hash
filterHeader chainhash.Hash
}
// server provides a bitcoin server for handling communications to and from
// bitcoin peers.
type server struct {
// The following variables must only be used atomically.
// Putting the uint64s first makes them 64-bit aligned for 32-bit systems.
bytesReceived uint64 // Total bytes received from all peers since start.
bytesSent uint64 // Total bytes sent by all peers since start.
started int32
shutdown int32
shutdownSched int32
startupTime int64
chainParams *chaincfg.Params
addrManager *addrmgr.AddrManager
connManager *connmgr.ConnManager
sigCache *txscript.SigCache
hashCache *txscript.HashCache
rpcServer *rpcServer
syncManager *netsync.SyncManager
chain *blockchain.BlockChain
txMemPool *mempool.TxPool
cpuMiner *cpuminer.CPUMiner
modifyRebroadcastInv chan interface{}
newPeers chan *serverPeer
donePeers chan *serverPeer
banPeers chan *serverPeer
query chan interface{}
relayInv chan relayMsg
broadcast chan broadcastMsg
peerHeightsUpdate chan updatePeerHeightsMsg
wg sync.WaitGroup
quit chan struct{}
nat NAT
db database.DB
timeSource blockchain.MedianTimeSource
services wire.ServiceFlag
// The following fields are used for optional indexes. They will be nil
// if the associated index is not enabled. These fields are set during
// initial creation of the server and never changed afterwards, so they
// do not need to be protected for concurrent access.
txIndex *indexers.TxIndex
addrIndex *indexers.AddrIndex
cfIndex *indexers.CfIndex
// The fee estimator keeps track of how long transactions are left in
// the mempool before they are mined into blocks.
feeEstimator *mempool.FeeEstimator
// cfCheckptCaches stores a cached slice of filter headers for cfcheckpt
// messages for each filter type.
cfCheckptCaches map[wire.FilterType][]cfHeaderKV
cfCheckptCachesMtx sync.RWMutex
}
// serverPeer extends the peer to maintain state shared by the server and
// the blockmanager.
type serverPeer struct {
// The following variables must only be used atomically
feeFilter int64
*peer.Peer
connReq *connmgr.ConnReq
server *server
persistent bool
continueHash *chainhash.Hash
relayMtx sync.Mutex
disableRelayTx bool
sentAddrs bool
isWhitelisted bool
filter *bloom.Filter
addrMtx sync.RWMutex
knownAddresses map[string]struct{}
banScore connmgr.DynamicBanScore
quit chan struct{}
// The following chans are used to sync blockmanager and server.
txProcessed chan struct{}
blockProcessed chan struct{}
}
// newServerPeer returns a new serverPeer instance. The peer needs to be set by
// the caller.
func newServerPeer(s *server, isPersistent bool) *serverPeer {
return &serverPeer{
server: s,
persistent: isPersistent,
filter: bloom.LoadFilter(nil),
knownAddresses: make(map[string]struct{}),
quit: make(chan struct{}),
txProcessed: make(chan struct{}, 1),
blockProcessed: make(chan struct{}, 1),
}
}
// newestBlock returns the current best block hash and height using the format
// required by the configuration for the peer package.
func (sp *serverPeer) newestBlock() (*chainhash.Hash, int32, error) {
best := sp.server.chain.BestSnapshot()
return &best.Hash, best.Height, nil
}
// addKnownAddresses adds the given addresses to the set of known addresses to
// the peer to prevent sending duplicate addresses.
func (sp *serverPeer) addKnownAddresses(addresses []*wire.NetAddress) {
sp.addrMtx.Lock()
defer sp.addrMtx.Unlock()
for _, na := range addresses {
sp.knownAddresses[addrmgr.NetAddressKey(na)] = struct{}{}
}
}
// addressKnown true if the given address is already known to the peer.
func (sp *serverPeer) addressKnown(na *wire.NetAddress) bool {
sp.addrMtx.RLock()
defer sp.addrMtx.RUnlock()
_, exists := sp.knownAddresses[addrmgr.NetAddressKey(na)]
return exists
}
// setDisableRelayTx toggles relaying of transactions for the given peer.
// It is safe for concurrent access.
func (sp *serverPeer) setDisableRelayTx(disable bool) {
sp.relayMtx.Lock()
sp.disableRelayTx = disable
sp.relayMtx.Unlock()
}
// relayTxDisabled returns whether or not relaying of transactions for the given
// peer is disabled.
// It is safe for concurrent access.
func (sp *serverPeer) relayTxDisabled() bool {
sp.relayMtx.Lock()
isDisabled := sp.disableRelayTx
sp.relayMtx.Unlock()
return isDisabled
}
// pushAddrMsg sends an addr message to the connected peer using the provided
// addresses.
func (sp *serverPeer) pushAddrMsg(addresses []*wire.NetAddress) {
// Filter addresses already known to the peer.
addrs := make([]*wire.NetAddress, 0, len(addresses))
for _, addr := range addresses {
if !sp.addressKnown(addr) {
addrs = append(addrs, addr)
}
}
known, err := sp.PushAddrMsg(addrs)
if err != nil {
peerLog.Errorf("Can't push address message to %s: %v", sp.Peer, err)
sp.Disconnect()
return
}
sp.addKnownAddresses(known)
}
// addBanScore increases the persistent and decaying ban score fields by the
// values passed as parameters. If the resulting score exceeds half of the ban
// threshold, a warning is logged including the reason provided. Further, if
// the score is above the ban threshold, the peer will be banned and
// disconnected.
func (sp *serverPeer) addBanScore(persistent, transient uint32, reason string) {
// No warning is logged and no score is calculated if banning is disabled.
if cfg.DisableBanning {
return
}
if sp.isWhitelisted {
peerLog.Debugf("Misbehaving whitelisted peer %s: %s", sp, reason)
return
}
warnThreshold := cfg.BanThreshold >> 1
if transient == 0 && persistent == 0 {
// The score is not being increased, but a warning message is still
// logged if the score is above the warn threshold.
score := sp.banScore.Int()
if score > warnThreshold {
peerLog.Warnf("Misbehaving peer %s: %s -- ban score is %d, "+
"it was not increased this time", sp, reason, score)
}
return
}
score := sp.banScore.Increase(persistent, transient)
if score > warnThreshold {
peerLog.Warnf("Misbehaving peer %s: %s -- ban score increased to %d",
sp, reason, score)
if score > cfg.BanThreshold {
peerLog.Warnf("Misbehaving peer %s -- banning and disconnecting",
sp)
sp.server.BanPeer(sp)
sp.Disconnect()
}
}
}
// hasServices returns whether or not the provided advertised service flags have
// all of the provided desired service flags set.
func hasServices(advertised, desired wire.ServiceFlag) bool {
return advertised&desired == desired
}
// OnVersion is invoked when a peer receives a version bitcoin message
// and is used to negotiate the protocol version details as well as kick start
// the communications.
func (sp *serverPeer) OnVersion(_ *peer.Peer, msg *wire.MsgVersion) *wire.MsgReject {
// Update the address manager with the advertised services for outbound
// connections in case they have changed. This is not done for inbound
// connections to help prevent malicious behavior and is skipped when
// running on the simulation test network since it is only intended to
// connect to specified peers and actively avoids advertising and
// connecting to discovered peers.
//
// NOTE: This is done before rejecting peers that are too old to ensure
// it is updated regardless in the case a new minimum protocol version is
// enforced and the remote node has not upgraded yet.
isInbound := sp.Inbound()
remoteAddr := sp.NA()
addrManager := sp.server.addrManager
if !cfg.SimNet && !isInbound {
addrManager.SetServices(remoteAddr, msg.Services)
}
// Ignore peers that have a protcol version that is too old. The peer
// negotiation logic will disconnect it after this callback returns.
if msg.ProtocolVersion < int32(peer.MinAcceptableProtocolVersion) {
return nil
}
// Do not allow connections to Bitcoin SV peers
if strings.Contains(msg.UserAgent, "Bitcoin SV") {
srvrLog.Debugf("Rejecting peer %s for running Bitcoin SV", sp.Peer)
reason := fmt.Sprint("Not Bitcoin Cash node")
return wire.NewMsgReject(msg.Command(), wire.RejectNonstandard, reason)
}
// Reject outbound peers that are not full nodes.
wantServices := wire.SFNodeNetwork
if !isInbound && !hasServices(msg.Services, wantServices) {
missingServices := wantServices & ^msg.Services
srvrLog.Debugf("Rejecting peer %s with services %v due to not "+
"providing desired services %v", sp.Peer, msg.Services,
missingServices)
reason := fmt.Sprintf("required services %#x not offered",
uint64(missingServices))
return wire.NewMsgReject(msg.Command(), wire.RejectNonstandard, reason)
}
// Update the address manager and request known addresses from the
// remote peer for outbound connections. This is skipped when running
// on the simulation test network since it is only intended to connect
// to specified peers and actively avoids advertising and connecting to
// discovered peers.
if !cfg.SimNet && !isInbound {
// Advertise the local address when the server accepts incoming
// connections and it believes itself to be close to the best known tip.
if !cfg.DisableListen && sp.server.syncManager.IsCurrent() {
// Get address that best matches.
lna := addrManager.GetBestLocalAddress(remoteAddr)
if addrmgr.IsRoutable(lna) {
// Filter addresses the peer already knows about.
addresses := []*wire.NetAddress{lna}
sp.pushAddrMsg(addresses)
}
}
// Request known addresses if the server address manager needs
// more and the peer has a protocol version new enough to
// include a timestamp with addresses.
hasTimestamp := sp.ProtocolVersion() >= wire.NetAddressTimeVersion
if addrManager.NeedMoreAddresses() && hasTimestamp {
sp.QueueMessage(wire.NewMsgGetAddr(), nil)
}
// Mark the address as a known good address.
addrManager.Good(remoteAddr)
}
// Add the remote peer time as a sample for creating an offset against
// the local clock to keep the network time in sync.
sp.server.timeSource.AddTimeSample(sp.Addr(), msg.Timestamp)
// Signal the sync manager this peer is a new sync candidate.
sp.server.syncManager.NewPeer(sp.Peer, nil)
// Choose whether or not to relay transactions before a filter command
// is received.
sp.setDisableRelayTx(msg.DisableRelayTx)
// Add valid peer to the server.
sp.server.AddPeer(sp)
return nil
}
// OnMemPool is invoked when a peer receives a mempool bitcoin message.
// It creates and sends an inventory message with the contents of the memory
// pool up to the maximum inventory allowed per message. When the peer has a
// bloom filter loaded, the contents are filtered accordingly.
func (sp *serverPeer) OnMemPool(_ *peer.Peer, msg *wire.MsgMemPool) {
// Only allow mempool requests if the server has bloom filtering
// enabled.
if sp.server.services&wire.SFNodeBloom != wire.SFNodeBloom {
peerLog.Debugf("peer %v sent mempool request with bloom "+
"filtering disabled -- disconnecting", sp)
sp.Disconnect()
return
}
// A decaying ban score increase is applied to prevent flooding.
// The ban score accumulates and passes the ban threshold if a burst of
// mempool messages comes from a peer. The score decays each minute to
// half of its value.
sp.addBanScore(0, 33, "mempool")
// Generate inventory message with the available transactions in the
// transaction memory pool. Limit it to the max allowed inventory
// per message. The NewMsgInvSizeHint function automatically limits
// the passed hint to the maximum allowed, so it's safe to pass it
// without double checking it here.
txMemPool := sp.server.txMemPool
txDescs := txMemPool.TxDescs()
invMsg := wire.NewMsgInvSizeHint(uint(len(txDescs)))
for _, txDesc := range txDescs {
// Either add all transactions when there is no bloom filter,
// or only the transactions that match the filter when there is
// one.
if !sp.filter.IsLoaded() || sp.filter.MatchTxAndUpdate(txDesc.Tx) {
iv := wire.NewInvVect(wire.InvTypeTx, txDesc.Tx.Hash())
invMsg.AddInvVect(iv)
if len(invMsg.InvList)+1 > wire.MaxInvPerMsg {
break
}
}
}
// Send the inventory message if there is anything to send.
if len(invMsg.InvList) > 0 {
sp.QueueMessage(invMsg, nil)
}
}
// OnTx is invoked when a peer receives a tx bitcoin message. It blocks
// until the bitcoin transaction has been fully processed. Unlock the block
// handler this does not serialize all transactions through a single thread
// transactions don't rely on the previous one in a linear fashion like blocks.
func (sp *serverPeer) OnTx(_ *peer.Peer, msg *wire.MsgTx) {
if cfg.BlocksOnly {
peerLog.Tracef("Ignoring tx %v from %v - blocksonly enabled",
msg.TxHash(), sp)
return
}
// Add the transaction to the known inventory for the peer.
// Convert the raw MsgTx to a bchutil.Tx which provides some convenience
// methods and things such as hash caching.
tx := bchutil.NewTx(msg)
iv := wire.NewInvVect(wire.InvTypeTx, tx.Hash())
sp.AddKnownInventory(iv)
// Queue the transaction up to be handled by the sync manager and
// intentionally block further receives until the transaction is fully
// processed and known good or bad. This helps prevent a malicious peer
// from queuing up a bunch of bad transactions before disconnecting (or
// being disconnected) and wasting memory.
sp.server.syncManager.QueueTx(tx, sp.Peer, sp.txProcessed)
<-sp.txProcessed
}
// OnBlock is invoked when a peer receives a block bitcoin message. It
// blocks until the bitcoin block has been fully processed.
func (sp *serverPeer) OnBlock(_ *peer.Peer, msg *wire.MsgBlock, buf []byte) {
// Convert the raw MsgBlock to a bchutil.Block which provides some
// convenience methods and things such as hash caching.
block := bchutil.NewBlockFromBlockAndBytes(msg, buf)
// Add the block to the known inventory for the peer.
iv := wire.NewInvVect(wire.InvTypeBlock, block.Hash())
sp.AddKnownInventory(iv)
// Queue the block up to be handled by the block
// manager and intentionally block further receives
// until the bitcoin block is fully processed and known
// good or bad. This helps prevent a malicious peer
// from queuing up a bunch of bad blocks before
// disconnecting (or being disconnected) and wasting
// memory. Additionally, this behavior is depended on
// by at least the block acceptance test tool as the
// reference implementation processes blocks in the same
// thread and therefore blocks further messages until
// the bitcoin block has been fully processed.
sp.server.syncManager.QueueBlock(block, sp.Peer, sp.blockProcessed)
<-sp.blockProcessed
}
// OnInv is invoked when a peer receives an inv bitcoin message and is
// used to examine the inventory being advertised by the remote peer and react
// accordingly. We pass the message down to blockmanager which will call
// QueueMessage with any appropriate responses.
func (sp *serverPeer) OnInv(_ *peer.Peer, msg *wire.MsgInv) {
if !cfg.BlocksOnly {
if len(msg.InvList) > 0 {
sp.server.syncManager.QueueInv(msg, sp.Peer)
}
return
}
newInv := wire.NewMsgInvSizeHint(uint(len(msg.InvList)))
for _, invVect := range msg.InvList {
if invVect.Type == wire.InvTypeTx {
peerLog.Tracef("Ignoring tx %v in inv from %v -- "+
"blocksonly enabled", invVect.Hash, sp)
if sp.ProtocolVersion() >= wire.BIP0037Version {
peerLog.Infof("Peer %v is announcing "+
"transactions -- disconnecting", sp)
sp.Disconnect()
return
}
continue
}
err := newInv.AddInvVect(invVect)
if err != nil {
peerLog.Errorf("Failed to add inventory vector: %v", err)
break
}
}
if len(newInv.InvList) > 0 {
sp.server.syncManager.QueueInv(newInv, sp.Peer)
}
}
// OnHeaders is invoked when a peer receives a headers bitcoin
// message. The message is passed down to the sync manager.
func (sp *serverPeer) OnHeaders(_ *peer.Peer, msg *wire.MsgHeaders) {
sp.server.syncManager.QueueHeaders(msg, sp.Peer)
}
// handleGetData is invoked when a peer receives a getdata bitcoin message and
// is used to deliver block and transaction information.
func (sp *serverPeer) OnGetData(_ *peer.Peer, msg *wire.MsgGetData) {
numAdded := 0
notFound := wire.NewMsgNotFound()
length := len(msg.InvList)
// A decaying ban score increase is applied to prevent exhausting resources
// with unusually large inventory queries.
// Requesting more than the maximum inventory vector length within a short
// period of time yields a score above the default ban threshold. Sustained
// bursts of small requests are not penalized as that would potentially ban
// peers performing IBD.
// This incremental score decays each minute to half of its value.
sp.addBanScore(0, uint32(length)*99/wire.MaxInvPerMsg, "getdata")
// We wait on this wait channel periodically to prevent queuing
// far more data than we can send in a reasonable time, wasting memory.
// The waiting occurs after the database fetch for the next one to
// provide a little pipelining.
var waitChan chan struct{}
doneChan := make(chan struct{}, 1)
for i, iv := range msg.InvList {
var c chan struct{}
// If this will be the last message we send.
if i == length-1 && len(notFound.InvList) == 0 {
c = doneChan
} else if (i+1)%3 == 0 {
// Buffered so as to not make the send goroutine block.
c = make(chan struct{}, 1)
}
var err error
switch iv.Type {
case wire.InvTypeTx:
err = sp.server.pushTxMsg(sp, &iv.Hash, c, waitChan, wire.BaseEncoding)
case wire.InvTypeBlock:
err = sp.server.pushBlockMsg(sp, &iv.Hash, c, waitChan, wire.BaseEncoding)
case wire.InvTypeFilteredBlock:
err = sp.server.pushMerkleBlockMsg(sp, &iv.Hash, c, waitChan, wire.BaseEncoding)
default:
peerLog.Warnf("Unknown type in inventory request %d",
iv.Type)
continue
}
if err != nil {
notFound.AddInvVect(iv)
// When there is a failure fetching the final entry
// and the done channel was sent in due to there
// being no outstanding not found inventory, consume
// it here because there is now not found inventory
// that will use the channel momentarily.
if i == len(msg.InvList)-1 && c != nil {
<-c
}
}
numAdded++
waitChan = c
}
if len(notFound.InvList) != 0 {
sp.QueueMessage(notFound, doneChan)
}
// Wait for messages to be sent. We can send quite a lot of data at this
// point and this will keep the peer busy for a decent amount of time.
// We don't process anything else by them in this time so that we
// have an idea of when we should hear back from them - else the idle
// timeout could fire when we were only half done sending the blocks.
if numAdded > 0 {
<-doneChan
}
}
// OnGetBlocks is invoked when a peer receives a getblocks bitcoin
// message.
func (sp *serverPeer) OnGetBlocks(_ *peer.Peer, msg *wire.MsgGetBlocks) {
// Find the most recent known block in the best chain based on the block
// locator and fetch all of the block hashes after it until either
// wire.MaxBlocksPerMsg have been fetched or the provided stop hash is
// encountered.
//
// Use the block after the genesis block if no other blocks in the
// provided locator are known. This does mean the client will start
// over with the genesis block if unknown block locators are provided.
//
// This mirrors the behavior in the reference implementation.
chain := sp.server.chain
hashList := chain.LocateBlocks(msg.BlockLocatorHashes, &msg.HashStop,
wire.MaxBlocksPerMsg)
// Generate inventory message.
invMsg := wire.NewMsgInv()
for i := range hashList {
iv := wire.NewInvVect(wire.InvTypeBlock, &hashList[i])
invMsg.AddInvVect(iv)
}
// Send the inventory message if there is anything to send.
if len(invMsg.InvList) > 0 {
invListLen := len(invMsg.InvList)
if invListLen == wire.MaxBlocksPerMsg {
// Intentionally use a copy of the final hash so there
// is not a reference into the inventory slice which
// would prevent the entire slice from being eligible
// for GC as soon as it's sent.
continueHash := invMsg.InvList[invListLen-1].Hash
sp.continueHash = &continueHash
}
sp.QueueMessage(invMsg, nil)
} else if sp.server.chain.PruneMode() {
// Typically nodes will just not respond to a GetBlocks message
// if they don't have any blocks. However, since we are implementing
// NodeNetworkLimited we need a better way to communicate to the remote
// peer that we don't have that portion of the chain than just letting
// the request timeout. So for this purpose we will respond with a
// not found message.
notFound := wire.NewMsgNotFound()
for _, inv := range invMsg.InvList {
notFound.AddInvVect(inv)
}
sp.QueueMessage(notFound, nil)
}
}
// OnGetHeaders is invoked when a peer receives a getheaders bitcoin
// message.
func (sp *serverPeer) OnGetHeaders(_ *peer.Peer, msg *wire.MsgGetHeaders) {
// Ignore getheaders requests if not in sync.
if !sp.server.syncManager.IsCurrent() {
return
}
// Find the most recent known block in the best chain based on the block
// locator and fetch all of the headers after it until either
// wire.MaxBlockHeadersPerMsg have been fetched or the provided stop
// hash is encountered.
//
// Use the block after the genesis block if no other blocks in the
// provided locator are known. This does mean the client will start
// over with the genesis block if unknown block locators are provided.
//
// This mirrors the behavior in the reference implementation.
chain := sp.server.chain
headers := chain.LocateHeaders(msg.BlockLocatorHashes, &msg.HashStop)
// Send found headers to the requesting peer.
blockHeaders := make([]*wire.BlockHeader, len(headers))
for i := range headers {
blockHeaders[i] = &headers[i]
}
sp.QueueMessage(&wire.MsgHeaders{Headers: blockHeaders}, nil)
}
// OnGetCFilters is invoked when a peer receives a getcfilters bitcoin message.
func (sp *serverPeer) OnGetCFilters(_ *peer.Peer, msg *wire.MsgGetCFilters) {
// Ignore getcfilters requests if not in sync.
if !sp.server.syncManager.IsCurrent() {
return
}
// We'll also ensure that the remote party is requesting a set of
// filters that we actually currently maintain.
switch msg.FilterType {
case wire.GCSFilterRegular:
break
default:
peerLog.Debug("Filter request for unknown filter: %v",
msg.FilterType)
return
}
hashes, err := sp.server.chain.HeightToHashRange(
int32(msg.StartHeight), &msg.StopHash, wire.MaxGetCFiltersReqRange,
)
if err != nil {
peerLog.Debugf("Invalid getcfilters request: %v", err)
return
}
// Create []*chainhash.Hash from []chainhash.Hash to pass to
// FiltersByBlockHashes.
hashPtrs := make([]*chainhash.Hash, len(hashes))
for i := range hashes {
hashPtrs[i] = &hashes[i]
}
filters, err := sp.server.cfIndex.FiltersByBlockHashes(
hashPtrs, msg.FilterType,
)
if err != nil {
peerLog.Errorf("Error retrieving cfilters: %v", err)
return
}
for i, filterBytes := range filters {
if len(filterBytes) == 0 {
peerLog.Warnf("Could not obtain cfilter for %v",
hashes[i])
return
}
filterMsg := wire.NewMsgCFilter(
msg.FilterType, &hashes[i], filterBytes,
)
sp.QueueMessage(filterMsg, nil)
}
}
// OnGetCFHeaders is invoked when a peer receives a getcfheader bitcoin message.
func (sp *serverPeer) OnGetCFHeaders(_ *peer.Peer, msg *wire.MsgGetCFHeaders) {
// Ignore getcfilterheader requests if not in sync.
if !sp.server.syncManager.IsCurrent() {
return
}
// We'll also ensure that the remote party is requesting a set of
// headers for filters that we actually currently maintain.
switch msg.FilterType {
case wire.GCSFilterRegular:
break
default:
peerLog.Debug("Filter request for unknown headers for "+
"filter: %v", msg.FilterType)
return
}
startHeight := int32(msg.StartHeight)
maxResults := wire.MaxCFHeadersPerMsg
// If StartHeight is positive, fetch the predecessor block hash so we
// can populate the PrevFilterHeader field.
if msg.StartHeight > 0 {
startHeight--
maxResults++
}
// Fetch the hashes from the block index.
hashList, err := sp.server.chain.HeightToHashRange(
startHeight, &msg.StopHash, maxResults,
)
if err != nil {
peerLog.Debugf("Invalid getcfheaders request: %v", err)
}
// This is possible if StartHeight is one greater that the height of
// StopHash, and we pull a valid range of hashes including the previous
// filter header.
if len(hashList) == 0 || (msg.StartHeight > 0 && len(hashList) == 1) {
peerLog.Debug("No results for getcfheaders request")
return
}
// Create []*chainhash.Hash from []chainhash.Hash to pass to
// FilterHeadersByBlockHashes.
hashPtrs := make([]*chainhash.Hash, len(hashList))
for i := range hashList {
hashPtrs[i] = &hashList[i]
}
// Fetch the raw filter hash bytes from the database for all blocks.
filterHashes, err := sp.server.cfIndex.FilterHashesByBlockHashes(
hashPtrs, msg.FilterType,
)
if err != nil {
peerLog.Errorf("Error retrieving cfilter hashes: %v", err)
return
}
// Generate cfheaders message and send it.
headersMsg := wire.NewMsgCFHeaders()
// Populate the PrevFilterHeader field.
if msg.StartHeight > 0 {
prevBlockHash := &hashList[0]
// Fetch the raw committed filter header bytes from the
// database.
headerBytes, err := sp.server.cfIndex.FilterHeaderByBlockHash(
prevBlockHash, msg.FilterType)
if err != nil {
peerLog.Errorf("Error retrieving CF header: %v", err)
return
}
if len(headerBytes) == 0 {
peerLog.Warnf("Could not obtain CF header for %v", prevBlockHash)
return
}
// Deserialize the hash into PrevFilterHeader.
err = headersMsg.PrevFilterHeader.SetBytes(headerBytes)
if err != nil {
peerLog.Warnf("Committed filter header deserialize "+
"failed: %v", err)
return
}
hashList = hashList[1:]
filterHashes = filterHashes[1:]
}
// Populate HeaderHashes.
for i, hashBytes := range filterHashes {
if len(hashBytes) == 0 {
peerLog.Warnf("Could not obtain CF hash for %v", hashList[i])
return
}
// Deserialize the hash.
filterHash, err := chainhash.NewHash(hashBytes)
if err != nil {
peerLog.Warnf("Committed filter hash deserialize "+
"failed: %v", err)
return
}
headersMsg.AddCFHash(filterHash)
}
headersMsg.FilterType = msg.FilterType
headersMsg.StopHash = msg.StopHash
sp.QueueMessage(headersMsg, nil)
}
// OnGetCFCheckpt is invoked when a peer receives a getcfcheckpt bitcoin message.
func (sp *serverPeer) OnGetCFCheckpt(_ *peer.Peer, msg *wire.MsgGetCFCheckpt) {
// Ignore getcfcheckpt requests if not in sync.
if !sp.server.syncManager.IsCurrent() {
return
}
// We'll also ensure that the remote party is requesting a set of
// checkpoints for filters that we actually currently maintain.
switch msg.FilterType {
case wire.GCSFilterRegular:
break
default:
peerLog.Debug("Filter request for unknown checkpoints for "+
"filter: %v", msg.FilterType)
return
}
// Now that we know the client is fetching a filter that we know of,
// we'll fetch the block hashes et each check point interval so we can
// compare against our cache, and create new check points if necessary.
blockHashes, err := sp.server.chain.IntervalBlockHashes(
&msg.StopHash, wire.CFCheckptInterval,
)
if err != nil {
peerLog.Debugf("Invalid getcfilters request: %v", err)
return
}
checkptMsg := wire.NewMsgCFCheckpt(
msg.FilterType, &msg.StopHash, len(blockHashes),