Official Go implementation of the Ethereum protocol
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go-ethereum/swarm/network/protocol.go

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// 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 (
"context"
"errors"
"fmt"
"net"
"sync"
"time"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/p2p/protocols"
"github.com/ethereum/go-ethereum/rpc"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/state"
)
const (
DefaultNetworkID = 3
// ProtocolMaxMsgSize maximum allowed message size
ProtocolMaxMsgSize = 10 * 1024 * 1024
// timeout for waiting
bzzHandshakeTimeout = 3000 * time.Millisecond
)
// BzzSpec is the spec of the generic swarm handshake
var BzzSpec = &protocols.Spec{
Name: "bzz",
Version: 5,
MaxMsgSize: 10 * 1024 * 1024,
Messages: []interface{}{
HandshakeMsg{},
},
}
// DiscoverySpec is the spec for the bzz discovery subprotocols
var DiscoverySpec = &protocols.Spec{
Name: "hive",
Version: 5,
MaxMsgSize: 10 * 1024 * 1024,
Messages: []interface{}{
peersMsg{},
subPeersMsg{},
},
}
// Addr interface that peerPool needs
type Addr interface {
OverlayPeer
Over() []byte
Under() []byte
String() string
Update(OverlayAddr) OverlayAddr
}
// Peer interface represents an live peer connection
type Peer interface {
Addr // the address of a peer
Conn // the live connection (protocols.Peer)
LastActive() time.Time // last time active
}
// Conn interface represents an live peer connection
type Conn interface {
ID() discover.NodeID // the key that uniquely identifies the Node for the peerPool
Handshake(context.Context, interface{}, func(interface{}) error) (interface{}, error) // can send messages
Send(context.Context, interface{}) error // can send messages
Drop(error) // disconnect this peer
Run(func(context.Context, interface{}) error) error // the run function to run a protocol
Off() OverlayAddr
}
// BzzConfig captures the config params used by the hive
type BzzConfig struct {
OverlayAddr []byte // base address of the overlay network
UnderlayAddr []byte // node's underlay address
HiveParams *HiveParams
NetworkID uint64
LightNode bool
}
// Bzz is the swarm protocol bundle
type Bzz struct {
*Hive
NetworkID uint64
LightNode bool
localAddr *BzzAddr
mtx sync.Mutex
handshakes map[discover.NodeID]*HandshakeMsg
streamerSpec *protocols.Spec
streamerRun func(*BzzPeer) error
}
// NewBzz is the swarm protocol constructor
// arguments
// * bzz config
// * overlay driver
// * peer store
func NewBzz(config *BzzConfig, kad Overlay, store state.Store, streamerSpec *protocols.Spec, streamerRun func(*BzzPeer) error) *Bzz {
return &Bzz{
Hive: NewHive(config.HiveParams, kad, store),
NetworkID: config.NetworkID,
LightNode: config.LightNode,
localAddr: &BzzAddr{config.OverlayAddr, config.UnderlayAddr},
handshakes: make(map[discover.NodeID]*HandshakeMsg),
streamerRun: streamerRun,
streamerSpec: streamerSpec,
}
}
// UpdateLocalAddr updates underlayaddress of the running node
func (b *Bzz) UpdateLocalAddr(byteaddr []byte) *BzzAddr {
b.localAddr = b.localAddr.Update(&BzzAddr{
UAddr: byteaddr,
OAddr: b.localAddr.OAddr,
}).(*BzzAddr)
return b.localAddr
}
// NodeInfo returns the node's overlay address
func (b *Bzz) NodeInfo() interface{} {
return b.localAddr.Address()
}
// Protocols return the protocols swarm offers
// Bzz implements the node.Service interface
// * handshake/hive
// * discovery
func (b *Bzz) Protocols() []p2p.Protocol {
protocol := []p2p.Protocol{
{
Name: BzzSpec.Name,
Version: BzzSpec.Version,
Length: BzzSpec.Length(),
Run: b.runBzz,
NodeInfo: b.NodeInfo,
},
{
Name: DiscoverySpec.Name,
Version: DiscoverySpec.Version,
Length: DiscoverySpec.Length(),
Run: b.RunProtocol(DiscoverySpec, b.Hive.Run),
NodeInfo: b.Hive.NodeInfo,
PeerInfo: b.Hive.PeerInfo,
},
}
if b.streamerSpec != nil && b.streamerRun != nil {
protocol = append(protocol, p2p.Protocol{
Name: b.streamerSpec.Name,
Version: b.streamerSpec.Version,
Length: b.streamerSpec.Length(),
Run: b.RunProtocol(b.streamerSpec, b.streamerRun),
})
}
return protocol
}
// APIs returns the APIs offered by bzz
// * hive
// Bzz implements the node.Service interface
func (b *Bzz) APIs() []rpc.API {
return []rpc.API{{
Namespace: "hive",
Version: "3.0",
Service: b.Hive,
}}
}
// RunProtocol is a wrapper for swarm subprotocols
// returns a p2p protocol run function that can be assigned to p2p.Protocol#Run field
// arguments:
// * p2p protocol spec
// * run function taking BzzPeer as argument
// this run function is meant to block for the duration of the protocol session
// on return the session is terminated and the peer is disconnected
// the protocol waits for the bzz handshake is negotiated
// the overlay address on the BzzPeer is set from the remote handshake
func (b *Bzz) RunProtocol(spec *protocols.Spec, run func(*BzzPeer) error) func(*p2p.Peer, p2p.MsgReadWriter) error {
return func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
// wait for the bzz protocol to perform the handshake
handshake, _ := b.GetHandshake(p.ID())
defer b.removeHandshake(p.ID())
select {
case <-handshake.done:
case <-time.After(bzzHandshakeTimeout):
return fmt.Errorf("%08x: %s protocol timeout waiting for handshake on %08x", b.BaseAddr()[:4], spec.Name, p.ID().Bytes()[:4])
}
if handshake.err != nil {
return fmt.Errorf("%08x: %s protocol closed: %v", b.BaseAddr()[:4], spec.Name, handshake.err)
}
// the handshake has succeeded so construct the BzzPeer and run the protocol
peer := &BzzPeer{
Peer: protocols.NewPeer(p, rw, spec),
localAddr: b.localAddr,
BzzAddr: handshake.peerAddr,
lastActive: time.Now(),
LightNode: handshake.LightNode,
}
log.Debug("peer created", "addr", handshake.peerAddr.String())
return run(peer)
}
}
// performHandshake implements the negotiation of the bzz handshake
// shared among swarm subprotocols
func (b *Bzz) performHandshake(p *protocols.Peer, handshake *HandshakeMsg) error {
ctx, cancel := context.WithTimeout(context.Background(), bzzHandshakeTimeout)
defer func() {
close(handshake.done)
cancel()
}()
rsh, err := p.Handshake(ctx, handshake, b.checkHandshake)
if err != nil {
handshake.err = err
return err
}
handshake.peerAddr = rsh.(*HandshakeMsg).Addr
handshake.LightNode = rsh.(*HandshakeMsg).LightNode
return nil
}
// runBzz is the p2p protocol run function for the bzz base protocol
// that negotiates the bzz handshake
func (b *Bzz) runBzz(p *p2p.Peer, rw p2p.MsgReadWriter) error {
handshake, _ := b.GetHandshake(p.ID())
if !<-handshake.init {
return fmt.Errorf("%08x: bzz already started on peer %08x", b.localAddr.Over()[:4], ToOverlayAddr(p.ID().Bytes())[:4])
}
close(handshake.init)
defer b.removeHandshake(p.ID())
peer := protocols.NewPeer(p, rw, BzzSpec)
err := b.performHandshake(peer, handshake)
if err != nil {
log.Warn(fmt.Sprintf("%08x: handshake failed with remote peer %08x: %v", b.localAddr.Over()[:4], ToOverlayAddr(p.ID().Bytes())[:4], err))
return err
}
// fail if we get another handshake
msg, err := rw.ReadMsg()
if err != nil {
return err
}
msg.Discard()
return errors.New("received multiple handshakes")
}
// BzzPeer is the bzz protocol view of a protocols.Peer (itself an extension of p2p.Peer)
// implements the Peer interface and all interfaces Peer implements: Addr, OverlayPeer
type BzzPeer struct {
*protocols.Peer // represents the connection for online peers
localAddr *BzzAddr // local Peers address
*BzzAddr // remote address -> implements Addr interface = protocols.Peer
lastActive time.Time // time is updated whenever mutexes are releasing
LightNode bool
}
func NewBzzTestPeer(p *protocols.Peer, addr *BzzAddr) *BzzPeer {
return &BzzPeer{
Peer: p,
localAddr: addr,
BzzAddr: NewAddrFromNodeID(p.ID()),
}
}
// Off returns the overlay peer record for offline persistence
func (p *BzzPeer) Off() OverlayAddr {
return p.BzzAddr
}
// LastActive returns the time the peer was last active
func (p *BzzPeer) LastActive() time.Time {
return p.lastActive
}
/*
Handshake
* Version: 8 byte integer version of the protocol
* NetworkID: 8 byte integer network identifier
* Addr: the address advertised by the node including underlay and overlay connecctions
*/
type HandshakeMsg struct {
Version uint64
NetworkID uint64
Addr *BzzAddr
LightNode bool
// peerAddr is the address received in the peer handshake
peerAddr *BzzAddr
init chan bool
done chan struct{}
err error
}
// String pretty prints the handshake
func (bh *HandshakeMsg) String() string {
return fmt.Sprintf("Handshake: Version: %v, NetworkID: %v, Addr: %v, LightNode: %v, peerAddr: %v", bh.Version, bh.NetworkID, bh.Addr, bh.LightNode, bh.peerAddr)
}
// Perform initiates the handshake and validates the remote handshake message
func (b *Bzz) checkHandshake(hs interface{}) error {
rhs := hs.(*HandshakeMsg)
if rhs.NetworkID != b.NetworkID {
return fmt.Errorf("network id mismatch %d (!= %d)", rhs.NetworkID, b.NetworkID)
}
if rhs.Version != uint64(BzzSpec.Version) {
return fmt.Errorf("version mismatch %d (!= %d)", rhs.Version, BzzSpec.Version)
}
return nil
}
// removeHandshake removes handshake for peer with peerID
// from the bzz handshake store
func (b *Bzz) removeHandshake(peerID discover.NodeID) {
b.mtx.Lock()
defer b.mtx.Unlock()
delete(b.handshakes, peerID)
}
// GetHandshake returns the bzz handhake that the remote peer with peerID sent
func (b *Bzz) GetHandshake(peerID discover.NodeID) (*HandshakeMsg, bool) {
b.mtx.Lock()
defer b.mtx.Unlock()
handshake, found := b.handshakes[peerID]
if !found {
handshake = &HandshakeMsg{
Version: uint64(BzzSpec.Version),
NetworkID: b.NetworkID,
Addr: b.localAddr,
LightNode: b.LightNode,
init: make(chan bool, 1),
done: make(chan struct{}),
}
// when handhsake is first created for a remote peer
// it is initialised with the init
handshake.init <- true
b.handshakes[peerID] = handshake
}
return handshake, found
}
// BzzAddr implements the PeerAddr interface
type BzzAddr struct {
OAddr []byte
UAddr []byte
}
// Address implements OverlayPeer interface to be used in Overlay
func (a *BzzAddr) Address() []byte {
return a.OAddr
}
// Over returns the overlay address
func (a *BzzAddr) Over() []byte {
return a.OAddr
}
// Under returns the underlay address
func (a *BzzAddr) Under() []byte {
return a.UAddr
}
// ID returns the nodeID from the underlay enode address
func (a *BzzAddr) ID() discover.NodeID {
return discover.MustParseNode(string(a.UAddr)).ID
}
// Update updates the underlay address of a peer record
func (a *BzzAddr) Update(na OverlayAddr) OverlayAddr {
return &BzzAddr{a.OAddr, na.(Addr).Under()}
}
// String pretty prints the address
func (a *BzzAddr) String() string {
return fmt.Sprintf("%x <%s>", a.OAddr, a.UAddr)
}
// RandomAddr is a utility method generating an address from a public key
func RandomAddr() *BzzAddr {
key, err := crypto.GenerateKey()
if err != nil {
panic("unable to generate key")
}
pubkey := crypto.FromECDSAPub(&key.PublicKey)
var id discover.NodeID
copy(id[:], pubkey[1:])
return NewAddrFromNodeID(id)
}
// NewNodeIDFromAddr transforms the underlay address to an adapters.NodeID
func NewNodeIDFromAddr(addr Addr) discover.NodeID {
log.Info(fmt.Sprintf("uaddr=%s", string(addr.Under())))
node := discover.MustParseNode(string(addr.Under()))
return node.ID
}
// NewAddrFromNodeID constucts a BzzAddr from a discover.NodeID
// the overlay address is derived as the hash of the nodeID
func NewAddrFromNodeID(id discover.NodeID) *BzzAddr {
return &BzzAddr{
OAddr: ToOverlayAddr(id.Bytes()),
UAddr: []byte(discover.NewNode(id, net.IP{127, 0, 0, 1}, 30303, 30303).String()),
}
}
// NewAddrFromNodeIDAndPort constucts a BzzAddr from a discover.NodeID and port uint16
// the overlay address is derived as the hash of the nodeID
func NewAddrFromNodeIDAndPort(id discover.NodeID, host net.IP, port uint16) *BzzAddr {
return &BzzAddr{
OAddr: ToOverlayAddr(id.Bytes()),
UAddr: []byte(discover.NewNode(id, host, port, port).String()),
}
}
// ToOverlayAddr creates an overlayaddress from a byte slice
func ToOverlayAddr(id []byte) []byte {
return crypto.Keccak256(id)
}