017831dd5b
This commit splits the eth package, separating the handling of eth and snap protocols. It also includes the capability to run snap sync (https://github.com/ethereum/devp2p/blob/master/caps/snap.md) , but does not enable it by default. Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de> Co-authored-by: Martin Holst Swende <martin@swende.se>
108 lines
3.5 KiB
Go
108 lines
3.5 KiB
Go
// 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 (
|
|
"fmt"
|
|
"math/big"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core/forkid"
|
|
"github.com/ethereum/go-ethereum/p2p"
|
|
)
|
|
|
|
const (
|
|
// handshakeTimeout is the maximum allowed time for the `eth` handshake to
|
|
// complete before dropping the connection.= as malicious.
|
|
handshakeTimeout = 5 * time.Second
|
|
)
|
|
|
|
// 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, forkID forkid.ID, forkFilter forkid.Filter) error {
|
|
// Send out own handshake in a new thread
|
|
errc := make(chan error, 2)
|
|
|
|
var status StatusPacket // safe to read after two values have been received from errc
|
|
|
|
go func() {
|
|
errc <- p2p.Send(p.rw, StatusMsg, &StatusPacket{
|
|
ProtocolVersion: uint32(p.version),
|
|
NetworkID: network,
|
|
TD: td,
|
|
Head: head,
|
|
Genesis: genesis,
|
|
ForkID: forkID,
|
|
})
|
|
}()
|
|
go func() {
|
|
errc <- p.readStatus(network, &status, genesis, forkFilter)
|
|
}()
|
|
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.Head
|
|
|
|
// TD at mainnet block #7753254 is 76 bits. If it becomes 100 million times
|
|
// larger, it will still fit within 100 bits
|
|
if tdlen := p.td.BitLen(); tdlen > 100 {
|
|
return fmt.Errorf("too large total difficulty: bitlen %d", tdlen)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// readStatus reads the remote handshake message.
|
|
func (p *Peer) readStatus(network uint64, status *StatusPacket, genesis common.Hash, forkFilter forkid.Filter) error {
|
|
msg, err := p.rw.ReadMsg()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if msg.Code != StatusMsg {
|
|
return fmt.Errorf("%w: first msg has code %x (!= %x)", errNoStatusMsg, msg.Code, StatusMsg)
|
|
}
|
|
if msg.Size > maxMessageSize {
|
|
return fmt.Errorf("%w: %v > %v", errMsgTooLarge, msg.Size, maxMessageSize)
|
|
}
|
|
// Decode the handshake and make sure everything matches
|
|
if err := msg.Decode(&status); err != nil {
|
|
return fmt.Errorf("%w: message %v: %v", errDecode, msg, err)
|
|
}
|
|
if status.NetworkID != network {
|
|
return fmt.Errorf("%w: %d (!= %d)", errNetworkIDMismatch, status.NetworkID, network)
|
|
}
|
|
if uint(status.ProtocolVersion) != p.version {
|
|
return fmt.Errorf("%w: %d (!= %d)", errProtocolVersionMismatch, status.ProtocolVersion, p.version)
|
|
}
|
|
if status.Genesis != genesis {
|
|
return fmt.Errorf("%w: %x (!= %x)", errGenesisMismatch, status.Genesis, genesis)
|
|
}
|
|
if err := forkFilter(status.ForkID); err != nil {
|
|
return fmt.Errorf("%w: %v", errForkIDRejected, err)
|
|
}
|
|
return nil
|
|
}
|