add necessary code base

1 files changed, 546 insertions, 0 deletions

diff --git a/eth/peer.go b/eth/peer.go
new file mode 100644
index 0000000..814c787
--- /dev/null
+++ b/eth/peer.go
@@ -0,0 +1,546 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package eth
+
+import (
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+	"time"
+
+	mapset "github.com/deckarep/golang-set"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+var (
+	errClosed            = errors.New("peer set is closed")
+	errAlreadyRegistered = errors.New("peer is already registered")
+	errNotRegistered     = errors.New("peer is not registered")
+)
+
+const (
+	maxKnownTxs    = 32768 // Maximum transactions hashes to keep in the known list (prevent DOS)
+	maxKnownBlocks = 1024  // Maximum block hashes to keep in the known list (prevent DOS)
+
+	// maxQueuedTxs is the maximum number of transaction lists to queue up before
+	// dropping broadcasts. This is a sensitive number as a transaction list might
+	// contain a single transaction, or thousands.
+	maxQueuedTxs = 128
+
+	// maxQueuedProps is the maximum number of block propagations to queue up before
+	// dropping broadcasts. There's not much point in queueing stale blocks, so a few
+	// that might cover uncles should be enough.
+	maxQueuedProps = 4
+
+	// maxQueuedAnns is the maximum number of block announcements to queue up before
+	// dropping broadcasts. Similarly to block propagations, there's no point to queue
+	// above some healthy uncle limit, so use that.
+	maxQueuedAnns = 4
+
+	handshakeTimeout = 5 * time.Second
+)
+
+// PeerInfo represents a short summary of the Ethereum sub-protocol metadata known
+// about a connected peer.
+type PeerInfo struct {
+	Version    int      `json:"version"`    // Ethereum protocol version negotiated
+	Difficulty *big.Int `json:"difficulty"` // Total difficulty of the peer's blockchain
+	Head       string   `json:"head"`       // SHA3 hash of the peer's best owned block
+}
+
+// propEvent is a block propagation, waiting for its turn in the broadcast queue.
+type propEvent struct {
+	block *types.Block
+	td    *big.Int
+}
+
+type peer struct {
+	id string
+
+	*p2p.Peer
+	rw p2p.MsgReadWriter
+
+	version  int         // Protocol version negotiated
+	syncDrop *time.Timer // Timed connection dropper if sync progress isn't validated in time
+
+	head common.Hash
+	td   *big.Int
+	lock sync.RWMutex
+
+	knownTxs    mapset.Set                // Set of transaction hashes known to be known by this peer
+	knownBlocks mapset.Set                // Set of block hashes known to be known by this peer
+	queuedTxs   chan []*types.Transaction // Queue of transactions to broadcast to the peer
+	queuedProps chan *propEvent           // Queue of blocks to broadcast to the peer
+	queuedAnns  chan *types.Block         // Queue of blocks to announce to the peer
+	term        chan struct{}             // Termination channel to stop the broadcaster
+}
+
+func newPeer(version int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
+	return &peer{
+		Peer:        p,
+		rw:          rw,
+		version:     version,
+		id:          fmt.Sprintf("%x", p.ID().Bytes()[:8]),
+		knownTxs:    mapset.NewSet(),
+		knownBlocks: mapset.NewSet(),
+		queuedTxs:   make(chan []*types.Transaction, maxQueuedTxs),
+		queuedProps: make(chan *propEvent, maxQueuedProps),
+		queuedAnns:  make(chan *types.Block, maxQueuedAnns),
+		term:        make(chan struct{}),
+	}
+}
+
+// broadcast is a write loop that multiplexes block propagations, announcements
+// and transaction broadcasts into the remote peer. The goal is to have an async
+// writer that does not lock up node internals.
+func (p *peer) broadcast() {
+	for {
+		select {
+		case txs := <-p.queuedTxs:
+			if err := p.SendTransactions(txs); err != nil {
+				return
+			}
+			p.Log().Trace("Broadcast transactions", "count", len(txs))
+
+		case prop := <-p.queuedProps:
+			if err := p.SendNewBlock(prop.block, prop.td); err != nil {
+				return
+			}
+			p.Log().Trace("Propagated block", "number", prop.block.Number(), "hash", prop.block.Hash(), "td", prop.td)
+
+		case block := <-p.queuedAnns:
+			if err := p.SendNewBlockHashes([]common.Hash{block.Hash()}, []uint64{block.NumberU64()}); err != nil {
+				return
+			}
+			p.Log().Trace("Announced block", "number", block.Number(), "hash", block.Hash())
+
+		case <-p.term:
+			return
+		}
+	}
+}
+
+// close signals the broadcast goroutine to terminate.
+func (p *peer) close() {
+	close(p.term)
+}
+
+// Info gathers and returns a collection of metadata known about a peer.
+func (p *peer) Info() *PeerInfo {
+	hash, td := p.Head()
+
+	return &PeerInfo{
+		Version:    p.version,
+		Difficulty: td,
+		Head:       hash.Hex(),
+	}
+}
+
+// Head retrieves a copy of the current head hash and total difficulty of the
+// peer.
+func (p *peer) Head() (hash common.Hash, td *big.Int) {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	copy(hash[:], p.head[:])
+	return hash, new(big.Int).Set(p.td)
+}
+
+// SetHead updates the head hash and total difficulty of the peer.
+func (p *peer) SetHead(hash common.Hash, td *big.Int) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	copy(p.head[:], hash[:])
+	p.td.Set(td)
+}
+
+// MarkBlock marks a block as known for the peer, ensuring that the block will
+// never be propagated to this particular peer.
+func (p *peer) MarkBlock(hash common.Hash) {
+	// If we reached the memory allowance, drop a previously known block hash
+	for p.knownBlocks.Cardinality() >= maxKnownBlocks {
+		p.knownBlocks.Pop()
+	}
+	p.knownBlocks.Add(hash)
+}
+
+// MarkTransaction marks a transaction as known for the peer, ensuring that it
+// will never be propagated to this particular peer.
+func (p *peer) MarkTransaction(hash common.Hash) {
+	// If we reached the memory allowance, drop a previously known transaction hash
+	for p.knownTxs.Cardinality() >= maxKnownTxs {
+		p.knownTxs.Pop()
+	}
+	p.knownTxs.Add(hash)
+}
+
+// SendTransactions sends transactions to the peer and includes the hashes
+// in its transaction hash set for future reference.
+func (p *peer) SendTransactions(txs types.Transactions) error {
+	// Mark all the transactions as known, but ensure we don't overflow our limits
+	for _, tx := range txs {
+		p.knownTxs.Add(tx.Hash())
+	}
+	for p.knownTxs.Cardinality() >= maxKnownTxs {
+		p.knownTxs.Pop()
+	}
+	return p2p.Send(p.rw, TxMsg, txs)
+}
+
+// AsyncSendTransactions queues list of transactions propagation to a remote
+// peer. If the peer's broadcast queue is full, the event is silently dropped.
+func (p *peer) AsyncSendTransactions(txs []*types.Transaction) {
+	select {
+	case p.queuedTxs <- txs:
+		// Mark all the transactions as known, but ensure we don't overflow our limits
+		for _, tx := range txs {
+			p.knownTxs.Add(tx.Hash())
+		}
+		for p.knownTxs.Cardinality() >= maxKnownTxs {
+			p.knownTxs.Pop()
+		}
+	default:
+		p.Log().Debug("Dropping transaction propagation", "count", len(txs))
+	}
+}
+
+// SendNewBlockHashes announces the availability of a number of blocks through
+// a hash notification.
+func (p *peer) SendNewBlockHashes(hashes []common.Hash, numbers []uint64) error {
+	// Mark all the block hashes as known, but ensure we don't overflow our limits
+	for _, hash := range hashes {
+		p.knownBlocks.Add(hash)
+	}
+	for p.knownBlocks.Cardinality() >= maxKnownBlocks {
+		p.knownBlocks.Pop()
+	}
+	request := make(newBlockHashesData, len(hashes))
+	for i := 0; i < len(hashes); i++ {
+		request[i].Hash = hashes[i]
+		request[i].Number = numbers[i]
+	}
+	return p2p.Send(p.rw, NewBlockHashesMsg, request)
+}
+
+// AsyncSendNewBlockHash queues the availability of a block for propagation to a
+// remote peer. If the peer's broadcast queue is full, the event is silently
+// dropped.
+func (p *peer) AsyncSendNewBlockHash(block *types.Block) {
+	select {
+	case p.queuedAnns <- block:
+		// Mark all the block hash as known, but ensure we don't overflow our limits
+		p.knownBlocks.Add(block.Hash())
+		for p.knownBlocks.Cardinality() >= maxKnownBlocks {
+			p.knownBlocks.Pop()
+		}
+	default:
+		p.Log().Debug("Dropping block announcement", "number", block.NumberU64(), "hash", block.Hash())
+	}
+}
+
+// SendNewBlock propagates an entire block to a remote peer.
+func (p *peer) SendNewBlock(block *types.Block, td *big.Int) error {
+	// Mark all the block hash as known, but ensure we don't overflow our limits
+	p.knownBlocks.Add(block.Hash())
+	for p.knownBlocks.Cardinality() >= maxKnownBlocks {
+		p.knownBlocks.Pop()
+	}
+	return p2p.Send(p.rw, NewBlockMsg, []interface{}{block, td})
+}
+
+// AsyncSendNewBlock queues an entire block for propagation to a remote peer. If
+// the peer's broadcast queue is full, the event is silently dropped.
+func (p *peer) AsyncSendNewBlock(block *types.Block, td *big.Int) {
+	select {
+	case p.queuedProps <- &propEvent{block: block, td: td}:
+		// Mark all the block hash as known, but ensure we don't overflow our limits
+		p.knownBlocks.Add(block.Hash())
+		for p.knownBlocks.Cardinality() >= maxKnownBlocks {
+			p.knownBlocks.Pop()
+		}
+	default:
+		p.Log().Debug("Dropping block propagation", "number", block.NumberU64(), "hash", block.Hash())
+	}
+}
+
+// SendBlockHeaders sends a batch of block headers to the remote peer.
+func (p *peer) SendBlockHeaders(headers []*types.Header) error {
+	return p2p.Send(p.rw, BlockHeadersMsg, headers)
+}
+
+// SendBlockBodies sends a batch of block contents to the remote peer.
+func (p *peer) SendBlockBodies(bodies []*blockBody) error {
+	return p2p.Send(p.rw, BlockBodiesMsg, blockBodiesData(bodies))
+}
+
+// SendBlockBodiesRLP sends a batch of block contents to the remote peer from
+// an already RLP encoded format.
+func (p *peer) SendBlockBodiesRLP(bodies []rlp.RawValue) error {
+	return p2p.Send(p.rw, BlockBodiesMsg, bodies)
+}
+
+// SendNodeDataRLP sends a batch of arbitrary internal data, corresponding to the
+// hashes requested.
+func (p *peer) SendNodeData(data [][]byte) error {
+	return p2p.Send(p.rw, NodeDataMsg, data)
+}
+
+// SendReceiptsRLP sends a batch of transaction receipts, corresponding to the
+// ones requested from an already RLP encoded format.
+func (p *peer) SendReceiptsRLP(receipts []rlp.RawValue) error {
+	return p2p.Send(p.rw, ReceiptsMsg, receipts)
+}
+
+// RequestOneHeader is a wrapper around the header query functions to fetch a
+// single header. It is used solely by the fetcher.
+func (p *peer) RequestOneHeader(hash common.Hash) error {
+	p.Log().Debug("Fetching single header", "hash", hash)
+	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Hash: hash}, Amount: uint64(1), Skip: uint64(0), Reverse: false})
+}
+
+// RequestHeadersByHash fetches a batch of blocks' headers corresponding to the
+// specified header query, based on the hash of an origin block.
+func (p *peer) RequestHeadersByHash(origin common.Hash, amount int, skip int, reverse bool) error {
+	p.Log().Debug("Fetching batch of headers", "count", amount, "fromhash", origin, "skip", skip, "reverse", reverse)
+	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
+}
+
+// RequestHeadersByNumber fetches a batch of blocks' headers corresponding to the
+// specified header query, based on the number of an origin block.
+func (p *peer) RequestHeadersByNumber(origin uint64, amount int, skip int, reverse bool) error {
+	p.Log().Debug("Fetching batch of headers", "count", amount, "fromnum", origin, "skip", skip, "reverse", reverse)
+	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Number: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
+}
+
+// RequestBodies fetches a batch of blocks' bodies corresponding to the hashes
+// specified.
+func (p *peer) RequestBodies(hashes []common.Hash) error {
+	p.Log().Debug("Fetching batch of block bodies", "count", len(hashes))
+	return p2p.Send(p.rw, GetBlockBodiesMsg, hashes)
+}
+
+// RequestNodeData fetches a batch of arbitrary data from a node's known state
+// data, corresponding to the specified hashes.
+func (p *peer) RequestNodeData(hashes []common.Hash) error {
+	p.Log().Debug("Fetching batch of state data", "count", len(hashes))
+	return p2p.Send(p.rw, GetNodeDataMsg, hashes)
+}
+
+// RequestReceipts fetches a batch of transaction receipts from a remote node.
+func (p *peer) RequestReceipts(hashes []common.Hash) error {
+	p.Log().Debug("Fetching batch of receipts", "count", len(hashes))
+	return p2p.Send(p.rw, GetReceiptsMsg, hashes)
+}
+
+// Handshake executes the eth protocol handshake, negotiating version number,
+// network IDs, difficulties, head and genesis blocks.
+func (p *peer) Handshake(network uint64, td *big.Int, head common.Hash, genesis common.Hash) error {
+	// Send out own handshake in a new thread
+	errc := make(chan error, 2)
+	var status statusData // safe to read after two values have been received from errc
+
+	go func() {
+		errc <- p2p.Send(p.rw, StatusMsg, &statusData{
+			ProtocolVersion: uint32(p.version),
+			NetworkId:       network,
+			TD:              td,
+			CurrentBlock:    head,
+			GenesisBlock:    genesis,
+		})
+	}()
+	go func() {
+		errc <- p.readStatus(network, &status, genesis)
+	}()
+	timeout := time.NewTimer(handshakeTimeout)
+	defer timeout.Stop()
+	for i := 0; i < 2; i++ {
+		select {
+		case err := <-errc:
+			if err != nil {
+				return err
+			}
+		case <-timeout.C:
+			return p2p.DiscReadTimeout
+		}
+	}
+	p.td, p.head = status.TD, status.CurrentBlock
+	return nil
+}
+
+func (p *peer) readStatus(network uint64, status *statusData, genesis common.Hash) (err error) {
+	msg, err := p.rw.ReadMsg()
+	if err != nil {
+		return err
+	}
+	if msg.Code != StatusMsg {
+		return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
+	}
+	if msg.Size > protocolMaxMsgSize {
+		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, protocolMaxMsgSize)
+	}
+	// Decode the handshake and make sure everything matches
+	if err := msg.Decode(&status); err != nil {
+		return errResp(ErrDecode, "msg %v: %v", msg, err)
+	}
+	if status.GenesisBlock != genesis {
+		return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status.GenesisBlock[:8], genesis[:8])
+	}
+	if status.NetworkId != network {
+		return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status.NetworkId, network)
+	}
+	if int(status.ProtocolVersion) != p.version {
+		return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, p.version)
+	}
+	return nil
+}
+
+// String implements fmt.Stringer.
+func (p *peer) String() string {
+	return fmt.Sprintf("Peer %s [%s]", p.id,
+		fmt.Sprintf("eth/%2d", p.version),
+	)
+}
+
+// peerSet represents the collection of active peers currently participating in
+// the Ethereum sub-protocol.
+type peerSet struct {
+	peers  map[string]*peer
+	lock   sync.RWMutex
+	closed bool
+}
+
+// newPeerSet creates a new peer set to track the active participants.
+func newPeerSet() *peerSet {
+	return &peerSet{
+		peers: make(map[string]*peer),
+	}
+}
+
+// Register injects a new peer into the working set, or returns an error if the
+// peer is already known. If a new peer it registered, its broadcast loop is also
+// started.
+func (ps *peerSet) Register(p *peer) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if ps.closed {
+		return errClosed
+	}
+	if _, ok := ps.peers[p.id]; ok {
+		return errAlreadyRegistered
+	}
+	ps.peers[p.id] = p
+	go p.broadcast()
+
+	return nil
+}
+
+// Unregister removes a remote peer from the active set, disabling any further
+// actions to/from that particular entity.
+func (ps *peerSet) Unregister(id string) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	p, ok := ps.peers[id]
+	if !ok {
+		return errNotRegistered
+	}
+	delete(ps.peers, id)
+	p.close()
+
+	return nil
+}
+
+// Peer retrieves the registered peer with the given id.
+func (ps *peerSet) Peer(id string) *peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	return ps.peers[id]
+}
+
+// Len returns if the current number of peers in the set.
+func (ps *peerSet) Len() int {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	return len(ps.peers)
+}
+
+// PeersWithoutBlock retrieves a list of peers that do not have a given block in
+// their set of known hashes.
+func (ps *peerSet) PeersWithoutBlock(hash common.Hash) []*peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	list := make([]*peer, 0, len(ps.peers))
+	for _, p := range ps.peers {
+		if !p.knownBlocks.Contains(hash) {
+			list = append(list, p)
+		}
+	}
+	return list
+}
+
+// PeersWithoutTx retrieves a list of peers that do not have a given transaction
+// in their set of known hashes.
+func (ps *peerSet) PeersWithoutTx(hash common.Hash) []*peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	list := make([]*peer, 0, len(ps.peers))
+	for _, p := range ps.peers {
+		if !p.knownTxs.Contains(hash) {
+			list = append(list, p)
+		}
+	}
+	return list
+}
+
+// BestPeer retrieves the known peer with the currently highest total difficulty.
+func (ps *peerSet) BestPeer() *peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	var (
+		bestPeer *peer
+		bestTd   *big.Int
+	)
+	for _, p := range ps.peers {
+		if _, td := p.Head(); bestPeer == nil || td.Cmp(bestTd) > 0 {
+			bestPeer, bestTd = p, td
+		}
+	}
+	return bestPeer
+}
+
+// Close disconnects all peers.
+// No new peers can be registered after Close has returned.
+func (ps *peerSet) Close() {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	for _, p := range ps.peers {
+		p.Disconnect(p2p.DiscQuitting)
+	}
+	ps.closed = true
+}