forked from bnb-chain/bsc
/
peerset.go
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/
peerset.go
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// Copyright 2020 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"
"math/big"
"sync"
"time"
"github.com/GittyGitGetGud/bsc/common"
"github.com/GittyGitGetGud/bsc/core"
"github.com/GittyGitGetGud/bsc/eth/downloader"
"github.com/GittyGitGetGud/bsc/eth/protocols/diff"
"github.com/GittyGitGetGud/bsc/eth/protocols/eth"
"github.com/GittyGitGetGud/bsc/eth/protocols/snap"
"github.com/GittyGitGetGud/bsc/eth/protocols/trust"
"github.com/GittyGitGetGud/bsc/p2p"
)
var (
// errPeerSetClosed is returned if a peer is attempted to be added or removed
// from the peer set after it has been terminated.
errPeerSetClosed = errors.New("peerset closed")
// errPeerAlreadyRegistered is returned if a peer is attempted to be added
// to the peer set, but one with the same id already exists.
errPeerAlreadyRegistered = errors.New("peer already registered")
// errPeerWaitTimeout is returned if a peer waits extension for too long
errPeerWaitTimeout = errors.New("peer wait timeout")
// errPeerNotRegistered is returned if a peer is attempted to be removed from
// a peer set, but no peer with the given id exists.
errPeerNotRegistered = errors.New("peer not registered")
// errSnapWithoutEth is returned if a peer attempts to connect only on the
// snap protocol without advertising the eth main protocol.
errSnapWithoutEth = errors.New("peer connected on snap without compatible eth support")
// errDiffWithoutEth is returned if a peer attempts to connect only on the
// diff protocol without advertising the eth main protocol.
errDiffWithoutEth = errors.New("peer connected on diff without compatible eth support")
// errTrustWithoutEth is returned if a peer attempts to connect only on the
// trust protocol without advertising the eth main protocol.
errTrustWithoutEth = errors.New("peer connected on trust without compatible eth support")
)
const (
// extensionWaitTimeout is the maximum allowed time for the extension wait to
// complete before dropping the connection as malicious.
extensionWaitTimeout = 10 * time.Second
)
// peerSet represents the collection of active peers currently participating in
// the `eth` protocol, with or without the `snap` extension.
type peerSet struct {
peers map[string]*ethPeer // Peers connected on the `eth` protocol
snapPeers int // Number of `snap` compatible peers for connection prioritization
snapWait map[string]chan *snap.Peer // Peers connected on `eth` waiting for their snap extension
snapPend map[string]*snap.Peer // Peers connected on the `snap` protocol, but not yet on `eth`
diffWait map[string]chan *diff.Peer // Peers connected on `eth` waiting for their diff extension
diffPend map[string]*diff.Peer // Peers connected on the `diff` protocol, but not yet on `eth`
trustWait map[string]chan *trust.Peer // Peers connected on `eth` waiting for their trust extension
trustPend map[string]*trust.Peer // Peers connected on the `trust` protocol, but not yet on `eth`
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]*ethPeer),
snapWait: make(map[string]chan *snap.Peer),
snapPend: make(map[string]*snap.Peer),
diffWait: make(map[string]chan *diff.Peer),
diffPend: make(map[string]*diff.Peer),
trustWait: make(map[string]chan *trust.Peer),
trustPend: make(map[string]*trust.Peer),
}
}
// registerSnapExtension unblocks an already connected `eth` peer waiting for its
// `snap` extension, or if no such peer exists, tracks the extension for the time
// being until the `eth` main protocol starts looking for it.
func (ps *peerSet) registerSnapExtension(peer *snap.Peer) error {
// Reject the peer if it advertises `snap` without `eth` as `snap` is only a
// satellite protocol meaningful with the chain selection of `eth`
if !peer.RunningCap(eth.ProtocolName, eth.ProtocolVersions) {
return errSnapWithoutEth
}
// Ensure nobody can double connect
ps.lock.Lock()
defer ps.lock.Unlock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.snapPend[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// Inject the peer into an `eth` counterpart is available, otherwise save for later
if wait, ok := ps.snapWait[id]; ok {
delete(ps.snapWait, id)
wait <- peer
return nil
}
ps.snapPend[id] = peer
return nil
}
// registerDiffExtension unblocks an already connected `eth` peer waiting for its
// `diff` extension, or if no such peer exists, tracks the extension for the time
// being until the `eth` main protocol starts looking for it.
func (ps *peerSet) registerDiffExtension(peer *diff.Peer) error {
// Reject the peer if it advertises `diff` without `eth` as `diff` is only a
// satellite protocol meaningful with the chain selection of `eth`
if !peer.RunningCap(eth.ProtocolName, eth.ProtocolVersions) {
return errDiffWithoutEth
}
// Ensure nobody can double connect
ps.lock.Lock()
defer ps.lock.Unlock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.diffPend[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// Inject the peer into an `eth` counterpart is available, otherwise save for later
if wait, ok := ps.diffWait[id]; ok {
delete(ps.diffWait, id)
wait <- peer
return nil
}
ps.diffPend[id] = peer
return nil
}
// registerTrustExtension unblocks an already connected `eth` peer waiting for its
// `trust` extension, or if no such peer exists, tracks the extension for the time
// being until the `eth` main protocol starts looking for it.
func (ps *peerSet) registerTrustExtension(peer *trust.Peer) error {
// Reject the peer if it advertises `trust` without `eth` as `trust` is only a
// satellite protocol meaningful with the chain selection of `eth`
if !peer.RunningCap(eth.ProtocolName, eth.ProtocolVersions) {
return errTrustWithoutEth
}
// If the peer isn't verify node, don't register trust extension into eth protocol.
if !peer.VerifyNode() {
return nil
}
// Ensure nobody can double connect
ps.lock.Lock()
defer ps.lock.Unlock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.trustPend[id]; ok {
return errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// Inject the peer into an `eth` counterpart is available, otherwise save for later
if wait, ok := ps.trustWait[id]; ok {
delete(ps.trustWait, id)
wait <- peer
return nil
}
ps.trustPend[id] = peer
return nil
}
// waitExtensions blocks until all satellite protocols are connected and tracked
// by the peerset.
func (ps *peerSet) waitSnapExtension(peer *eth.Peer) (*snap.Peer, error) {
// If the peer does not support a compatible `snap`, don't wait
if !peer.RunningCap(snap.ProtocolName, snap.ProtocolVersions) {
return nil, nil
}
// Ensure nobody can double connect
ps.lock.Lock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.snapWait[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// If `snap` already connected, retrieve the peer from the pending set
if snap, ok := ps.snapPend[id]; ok {
delete(ps.snapPend, id)
ps.lock.Unlock()
return snap, nil
}
// Otherwise wait for `snap` to connect concurrently
wait := make(chan *snap.Peer)
ps.snapWait[id] = wait
ps.lock.Unlock()
select {
case peer := <-wait:
return peer, nil
case <-time.After(extensionWaitTimeout):
ps.lock.Lock()
delete(ps.snapWait, id)
ps.lock.Unlock()
return nil, errPeerWaitTimeout
}
}
// waitDiffExtension blocks until all satellite protocols are connected and tracked
// by the peerset.
func (ps *peerSet) waitDiffExtension(peer *eth.Peer) (*diff.Peer, error) {
// If the peer does not support a compatible `diff`, don't wait
if !peer.RunningCap(diff.ProtocolName, diff.ProtocolVersions) {
return nil, nil
}
// Ensure nobody can double connect
ps.lock.Lock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.diffWait[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// If `diff` already connected, retrieve the peer from the pending set
if diff, ok := ps.diffPend[id]; ok {
delete(ps.diffPend, id)
ps.lock.Unlock()
return diff, nil
}
// Otherwise wait for `diff` to connect concurrently
wait := make(chan *diff.Peer)
ps.diffWait[id] = wait
ps.lock.Unlock()
select {
case peer := <-wait:
return peer, nil
case <-time.After(extensionWaitTimeout):
ps.lock.Lock()
delete(ps.diffWait, id)
ps.lock.Unlock()
return nil, errPeerWaitTimeout
}
}
// waitTrustExtension blocks until all satellite protocols are connected and tracked
// by the peerset.
func (ps *peerSet) waitTrustExtension(peer *eth.Peer) (*trust.Peer, error) {
// If the peer does not support a compatible `trust`, don't wait
if !peer.RunningCap(trust.ProtocolName, trust.ProtocolVersions) {
return nil, nil
}
// If the peer isn't verify node, don't register trust extension into eth protocol.
if !peer.VerifyNode() {
return nil, nil
}
// Ensure nobody can double connect
ps.lock.Lock()
id := peer.ID()
if _, ok := ps.peers[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as existing ones
}
if _, ok := ps.trustWait[id]; ok {
ps.lock.Unlock()
return nil, errPeerAlreadyRegistered // avoid connections with the same id as pending ones
}
// If `trust` already connected, retrieve the peer from the pending set
if trust, ok := ps.trustPend[id]; ok {
delete(ps.trustPend, id)
ps.lock.Unlock()
return trust, nil
}
// Otherwise wait for `trust` to connect concurrently
wait := make(chan *trust.Peer)
ps.trustWait[id] = wait
ps.lock.Unlock()
select {
case peer := <-wait:
return peer, nil
case <-time.After(extensionWaitTimeout):
ps.lock.Lock()
delete(ps.trustWait, id)
ps.lock.Unlock()
return nil, errPeerWaitTimeout
}
}
func (ps *peerSet) GetDiffPeer(pid string) downloader.IDiffPeer {
if p := ps.peer(pid); p != nil && p.diffExt != nil {
return p.diffExt
}
return nil
}
// GetVerifyPeers returns an array of verify nodes.
func (ps *peerSet) GetVerifyPeers() []core.VerifyPeer {
ps.lock.RLock()
defer ps.lock.RUnlock()
res := make([]core.VerifyPeer, 0)
for _, p := range ps.peers {
if p.trustExt != nil && p.trustExt.Peer != nil {
res = append(res, p.trustExt.Peer)
}
}
return res
}
// registerPeer injects a new `eth` peer into the working set, or returns an error
// if the peer is already known.
func (ps *peerSet) registerPeer(peer *eth.Peer, ext *snap.Peer, diffExt *diff.Peer, trustExt *trust.Peer) error {
// Start tracking the new peer
ps.lock.Lock()
defer ps.lock.Unlock()
if ps.closed {
return errPeerSetClosed
}
id := peer.ID()
if _, ok := ps.peers[id]; ok {
return errPeerAlreadyRegistered
}
eth := ðPeer{
Peer: peer,
}
if ext != nil {
eth.snapExt = &snapPeer{ext}
ps.snapPeers++
}
if diffExt != nil {
eth.diffExt = &diffPeer{diffExt}
}
if trustExt != nil {
eth.trustExt = &trustPeer{trustExt}
}
ps.peers[id] = eth
return nil
}
// unregisterPeer removes a remote peer from the active set, disabling any further
// actions to/from that particular entity.
func (ps *peerSet) unregisterPeer(id string) error {
ps.lock.Lock()
defer ps.lock.Unlock()
peer, ok := ps.peers[id]
if !ok {
return errPeerNotRegistered
}
delete(ps.peers, id)
if peer.snapExt != nil {
ps.snapPeers--
}
return nil
}
// peer retrieves the registered peer with the given id.
func (ps *peerSet) peer(id string) *ethPeer {
ps.lock.RLock()
defer ps.lock.RUnlock()
return ps.peers[id]
}
// headPeers retrieves a specified number list of peers.
func (ps *peerSet) headPeers(num uint) []*ethPeer {
ps.lock.RLock()
defer ps.lock.RUnlock()
if num > uint(len(ps.peers)) {
num = uint(len(ps.peers))
}
list := make([]*ethPeer, 0, num)
for _, p := range ps.peers {
list = append(list, p)
}
return list
}
// peersWithoutBlock retrieves a list of peers that do not have a given block in
// their set of known hashes so it might be propagated to them.
func (ps *peerSet) peersWithoutBlock(hash common.Hash) []*ethPeer {
ps.lock.RLock()
defer ps.lock.RUnlock()
list := make([]*ethPeer, 0, len(ps.peers))
for _, p := range ps.peers {
if !p.KnownBlock(hash) {
list = append(list, p)
}
}
return list
}
// peersWithoutTransaction retrieves a list of peers that do not have a given
// transaction in their set of known hashes.
func (ps *peerSet) peersWithoutTransaction(hash common.Hash) []*ethPeer {
ps.lock.RLock()
defer ps.lock.RUnlock()
list := make([]*ethPeer, 0, len(ps.peers))
for _, p := range ps.peers {
if !p.KnownTransaction(hash) {
list = append(list, p)
}
}
return list
}
// len returns if the current number of `eth` peers in the set. Since the `snap`
// peers are tied to the existence of an `eth` connection, that will always be a
// subset of `eth`.
func (ps *peerSet) len() int {
ps.lock.RLock()
defer ps.lock.RUnlock()
return len(ps.peers)
}
// snapLen returns if the current number of `snap` peers in the set.
func (ps *peerSet) snapLen() int {
ps.lock.RLock()
defer ps.lock.RUnlock()
return ps.snapPeers
}
// peerWithHighestTD retrieves the known peer with the currently highest total
// difficulty.
func (ps *peerSet) peerWithHighestTD() *eth.Peer {
ps.lock.RLock()
defer ps.lock.RUnlock()
var (
bestPeer *eth.Peer
bestTd *big.Int
)
for _, p := range ps.peers {
if _, td := p.Head(); bestPeer == nil || td.Cmp(bestTd) > 0 {
bestPeer, bestTd = p.Peer, td
}
}
return bestPeer
}
// close disconnects all peers.
func (ps *peerSet) close() {
ps.lock.Lock()
defer ps.lock.Unlock()
for _, p := range ps.peers {
p.Disconnect(p2p.DiscQuitting)
}
ps.closed = true
}