bsc/eth/protocols/diff/handshake.go
yutianwu 7c1c8e2e88
[R4R] add timeout for stopping p2p server (#643)
* add timeout for stopping p2p server

* extend extension wait time

* add unit tests

* fix lint issue
2021-12-13 11:16:03 +08:00

83 lines
2.3 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 diff
import (
"fmt"
"time"
"github.com/ethereum/go-ethereum/common/gopool"
"github.com/ethereum/go-ethereum/p2p"
)
const (
// handshakeTimeout is the maximum allowed time for the `diff` handshake to
// complete before dropping the connection as malicious.
handshakeTimeout = 5 * time.Second
)
// Handshake executes the diff protocol handshake,
func (p *Peer) Handshake(diffSync bool) error {
// Send out own handshake in a new thread
errc := make(chan error, 2)
var cap DiffCapPacket // safe to read after two values have been received from errc
gopool.Submit(func() {
errc <- p2p.Send(p.rw, DiffCapMsg, &DiffCapPacket{
DiffSync: diffSync,
Extra: defaultExtra,
})
})
gopool.Submit(func() {
errc <- p.readCap(&cap)
})
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.diffSync = cap.DiffSync
return nil
}
// readStatus reads the remote handshake message.
func (p *Peer) readCap(cap *DiffCapPacket) error {
msg, err := p.rw.ReadMsg()
if err != nil {
return err
}
if msg.Code != DiffCapMsg {
return fmt.Errorf("%w: first msg has code %x (!= %x)", errNoCapMsg, msg.Code, DiffCapMsg)
}
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(cap); err != nil {
return fmt.Errorf("%w: message %v: %v", errDecode, msg, err)
}
return nil
}