go-pulse/swarm/network/hive.go
Felix Lange 30cd5c1854
all: new p2p node representation (#17643)
Package p2p/enode provides a generalized representation of p2p nodes
which can contain arbitrary information in key/value pairs. It is also
the new home for the node database. The "v4" identity scheme is also
moved here from p2p/enr to remove the dependency on Ethereum crypto from
that package.

Record signature handling is changed significantly. The identity scheme
registry is removed and acceptable schemes must be passed to any method
that needs identity. This means records must now be validated explicitly
after decoding.

The enode API is designed to make signature handling easy and safe: most
APIs around the codebase work with enode.Node, which is a wrapper around
a valid record. Going from enr.Record to enode.Node requires a valid
signature.

* p2p/discover: port to p2p/enode

This ports the discovery code to the new node representation in
p2p/enode. The wire protocol is unchanged, this can be considered a
refactoring change. The Kademlia table can now deal with nodes using an
arbitrary identity scheme. This requires a few incompatible API changes:

  - Table.Lookup is not available anymore. It used to take a public key
    as argument because v4 protocol requires one. Its replacement is
    LookupRandom.
  - Table.Resolve takes *enode.Node instead of NodeID. This is also for
    v4 protocol compatibility because nodes cannot be looked up by ID
    alone.
  - Types Node and NodeID are gone. Further commits in the series will be
    fixes all over the the codebase to deal with those removals.

* p2p: port to p2p/enode and discovery changes

This adapts package p2p to the changes in p2p/discover. All uses of
discover.Node and discover.NodeID are replaced by their equivalents from
p2p/enode.

New API is added to retrieve the enode.Node instance of a peer. The
behavior of Server.Self with discovery disabled is improved. It now
tries much harder to report a working IP address, falling back to
127.0.0.1 if no suitable address can be determined through other means.
These changes were needed for tests of other packages later in the
series.

* p2p/simulations, p2p/testing: port to p2p/enode

No surprises here, mostly replacements of discover.Node, discover.NodeID
with their new equivalents. The 'interesting' API changes are:

 - testing.ProtocolSession tracks complete nodes, not just their IDs.
 - adapters.NodeConfig has a new method to create a complete node.

These changes were needed to make swarm tests work.

Note that the NodeID change makes the code incompatible with old
simulation snapshots.

* whisper/whisperv5, whisper/whisperv6: port to p2p/enode

This port was easy because whisper uses []byte for node IDs and
URL strings in the API.

* eth: port to p2p/enode

Again, easy to port because eth uses strings for node IDs and doesn't
care about node information in any way.

* les: port to p2p/enode

Apart from replacing discover.NodeID with enode.ID, most changes are in
the server pool code. It now deals with complete nodes instead
of (Pubkey, IP, Port) triples. The database format is unchanged for now,
but we should probably change it to use the node database later.

* node: port to p2p/enode

This change simply replaces discover.Node and discover.NodeID with their
new equivalents.

* swarm/network: port to p2p/enode

Swarm has its own node address representation, BzzAddr, containing both
an overlay address (the hash of a secp256k1 public key) and an underlay
address (enode:// URL).

There are no changes to the BzzAddr format in this commit, but certain
operations such as creating a BzzAddr from a node ID are now impossible
because node IDs aren't public keys anymore.

Most swarm-related changes in the series remove uses of
NewAddrFromNodeID, replacing it with NewAddr which takes a complete node
as argument. ToOverlayAddr is removed because we can just use the node
ID directly.
2018-09-25 00:59:00 +02:00

245 lines
7.1 KiB
Go

// Copyright 2016 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 network
import (
"fmt"
"sync"
"time"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/state"
)
/*
Hive is the logistic manager of the swarm
When the hive is started, a forever loop is launched that
asks the kademlia nodetable
to suggest peers to bootstrap connectivity
*/
// HiveParams holds the config options to hive
type HiveParams struct {
Discovery bool // if want discovery of not
PeersBroadcastSetSize uint8 // how many peers to use when relaying
MaxPeersPerRequest uint8 // max size for peer address batches
KeepAliveInterval time.Duration
}
// NewHiveParams returns hive config with only the
func NewHiveParams() *HiveParams {
return &HiveParams{
Discovery: true,
PeersBroadcastSetSize: 3,
MaxPeersPerRequest: 5,
KeepAliveInterval: 500 * time.Millisecond,
}
}
// Hive manages network connections of the swarm node
type Hive struct {
*HiveParams // settings
*Kademlia // the overlay connectiviy driver
Store state.Store // storage interface to save peers across sessions
addPeer func(*enode.Node) // server callback to connect to a peer
// bookkeeping
lock sync.Mutex
peers map[enode.ID]*BzzPeer
ticker *time.Ticker
}
// NewHive constructs a new hive
// HiveParams: config parameters
// Kademlia: connectivity driver using a network topology
// StateStore: to save peers across sessions
func NewHive(params *HiveParams, kad *Kademlia, store state.Store) *Hive {
return &Hive{
HiveParams: params,
Kademlia: kad,
Store: store,
peers: make(map[enode.ID]*BzzPeer),
}
}
// Start stars the hive, receives p2p.Server only at startup
// server is used to connect to a peer based on its NodeID or enode URL
// these are called on the p2p.Server which runs on the node
func (h *Hive) Start(server *p2p.Server) error {
log.Info("Starting hive", "baseaddr", fmt.Sprintf("%x", h.BaseAddr()[:4]))
// if state store is specified, load peers to prepopulate the overlay address book
if h.Store != nil {
log.Info("Detected an existing store. trying to load peers")
if err := h.loadPeers(); err != nil {
log.Error(fmt.Sprintf("%08x hive encoutered an error trying to load peers", h.BaseAddr()[:4]))
return err
}
}
// assigns the p2p.Server#AddPeer function to connect to peers
h.addPeer = server.AddPeer
// ticker to keep the hive alive
h.ticker = time.NewTicker(h.KeepAliveInterval)
// this loop is doing bootstrapping and maintains a healthy table
go h.connect()
return nil
}
// Stop terminates the updateloop and saves the peers
func (h *Hive) Stop() error {
log.Info(fmt.Sprintf("%08x hive stopping, saving peers", h.BaseAddr()[:4]))
h.ticker.Stop()
if h.Store != nil {
if err := h.savePeers(); err != nil {
return fmt.Errorf("could not save peers to persistence store: %v", err)
}
if err := h.Store.Close(); err != nil {
return fmt.Errorf("could not close file handle to persistence store: %v", err)
}
}
log.Info(fmt.Sprintf("%08x hive stopped, dropping peers", h.BaseAddr()[:4]))
h.EachConn(nil, 255, func(p *Peer, _ int, _ bool) bool {
log.Info(fmt.Sprintf("%08x dropping peer %08x", h.BaseAddr()[:4], p.Address()[:4]))
p.Drop(nil)
return true
})
log.Info(fmt.Sprintf("%08x all peers dropped", h.BaseAddr()[:4]))
return nil
}
// connect is a forever loop
// at each iteration, ask the overlay driver to suggest the most preferred peer to connect to
// as well as advertises saturation depth if needed
func (h *Hive) connect() {
for range h.ticker.C {
addr, depth, changed := h.SuggestPeer()
if h.Discovery && changed {
NotifyDepth(uint8(depth), h.Kademlia)
}
if addr == nil {
continue
}
log.Trace(fmt.Sprintf("%08x hive connect() suggested %08x", h.BaseAddr()[:4], addr.Address()[:4]))
under, err := enode.ParseV4(string(addr.Under()))
if err != nil {
log.Warn(fmt.Sprintf("%08x unable to connect to bee %08x: invalid node URL: %v", h.BaseAddr()[:4], addr.Address()[:4], err))
continue
}
log.Trace(fmt.Sprintf("%08x attempt to connect to bee %08x", h.BaseAddr()[:4], addr.Address()[:4]))
h.addPeer(under)
}
}
// Run protocol run function
func (h *Hive) Run(p *BzzPeer) error {
h.trackPeer(p)
defer h.untrackPeer(p)
dp := NewPeer(p, h.Kademlia)
depth, changed := h.On(dp)
// if we want discovery, advertise change of depth
if h.Discovery {
if changed {
// if depth changed, send to all peers
NotifyDepth(depth, h.Kademlia)
} else {
// otherwise just send depth to new peer
dp.NotifyDepth(depth)
}
}
NotifyPeer(p.BzzAddr, h.Kademlia)
defer h.Off(dp)
return dp.Run(dp.HandleMsg)
}
func (h *Hive) trackPeer(p *BzzPeer) {
h.lock.Lock()
h.peers[p.ID()] = p
h.lock.Unlock()
}
func (h *Hive) untrackPeer(p *BzzPeer) {
h.lock.Lock()
delete(h.peers, p.ID())
h.lock.Unlock()
}
// NodeInfo function is used by the p2p.server RPC interface to display
// protocol specific node information
func (h *Hive) NodeInfo() interface{} {
return h.String()
}
// PeerInfo function is used by the p2p.server RPC interface to display
// protocol specific information any connected peer referred to by their NodeID
func (h *Hive) PeerInfo(id enode.ID) interface{} {
h.lock.Lock()
p := h.peers[id]
h.lock.Unlock()
if p == nil {
return nil
}
addr := NewAddr(p.Node())
return struct {
OAddr hexutil.Bytes
UAddr hexutil.Bytes
}{
OAddr: addr.OAddr,
UAddr: addr.UAddr,
}
}
// loadPeers, savePeer implement persistence callback/
func (h *Hive) loadPeers() error {
var as []*BzzAddr
err := h.Store.Get("peers", &as)
if err != nil {
if err == state.ErrNotFound {
log.Info(fmt.Sprintf("hive %08x: no persisted peers found", h.BaseAddr()[:4]))
return nil
}
return err
}
log.Info(fmt.Sprintf("hive %08x: peers loaded", h.BaseAddr()[:4]))
return h.Register(as...)
}
// savePeers, savePeer implement persistence callback/
func (h *Hive) savePeers() error {
var peers []*BzzAddr
h.Kademlia.EachAddr(nil, 256, func(pa *BzzAddr, i int, _ bool) bool {
if pa == nil {
log.Warn(fmt.Sprintf("empty addr: %v", i))
return true
}
log.Trace("saving peer", "peer", pa)
peers = append(peers, pa)
return true
})
if err := h.Store.Put("peers", peers); err != nil {
return fmt.Errorf("could not save peers: %v", err)
}
return nil
}