2021-01-19 17:20:25 +02:00

116 lines
3.4 KiB
Go

package handshake
import (
"sync/atomic"
"github.com/kaspanet/kaspad/domain"
"github.com/kaspanet/kaspad/app/protocol/common"
"github.com/kaspanet/kaspad/app/protocol/protocolerrors"
"github.com/kaspanet/kaspad/infrastructure/network/addressmanager"
"github.com/kaspanet/kaspad/infrastructure/config"
"github.com/kaspanet/kaspad/infrastructure/network/netadapter"
"github.com/kaspanet/kaspad/app/appmessage"
peerpkg "github.com/kaspanet/kaspad/app/protocol/peer"
routerpkg "github.com/kaspanet/kaspad/infrastructure/network/netadapter/router"
"github.com/pkg/errors"
)
// HandleHandshakeContext is the interface for the context needed for the HandleHandshake flow.
type HandleHandshakeContext interface {
Config() *config.Config
NetAdapter() *netadapter.NetAdapter
Domain() domain.Domain
AddressManager() *addressmanager.AddressManager
AddToPeers(peer *peerpkg.Peer) error
HandleError(err error, flowName string, isStopping *uint32, errChan chan<- error)
}
// HandleHandshake sets up the handshake protocol - It sends a version message and waits for an incoming
// version message, as well as a verack for the sent version
func HandleHandshake(context HandleHandshakeContext, netConnection *netadapter.NetConnection,
receiveVersionRoute *routerpkg.Route, sendVersionRoute *routerpkg.Route, outgoingRoute *routerpkg.Route,
) (*peerpkg.Peer, error) {
// For HandleHandshake to finish, we need to get from the other node
// a version and verack messages, so we set doneCount to 2, decrease it
// when sending and receiving the version, and close the doneChan when
// it's 0. Then we wait for on select for a tick from doneChan or from
// errChan.
doneCount := int32(2)
doneChan := make(chan struct{})
isStopping := uint32(0)
errChan := make(chan error)
peer := peerpkg.New(netConnection)
var peerAddress *appmessage.NetAddress
spawn("HandleHandshake-ReceiveVersion", func() {
address, err := ReceiveVersion(context, receiveVersionRoute, outgoingRoute, peer)
if err != nil {
handleError(err, "ReceiveVersion", &isStopping, errChan)
return
}
peerAddress = address
if atomic.AddInt32(&doneCount, -1) == 0 {
close(doneChan)
}
})
spawn("HandleHandshake-SendVersion", func() {
err := SendVersion(context, sendVersionRoute, outgoingRoute, peer)
if err != nil {
handleError(err, "SendVersion", &isStopping, errChan)
return
}
if atomic.AddInt32(&doneCount, -1) == 0 {
close(doneChan)
}
})
select {
case err := <-errChan:
if err != nil {
return nil, err
}
return nil, nil
case <-doneChan:
}
err := context.AddToPeers(peer)
if err != nil {
if errors.Is(err, common.ErrPeerWithSameIDExists) {
return nil, protocolerrors.Wrap(false, err, "peer already exists")
}
return nil, err
}
if peerAddress != nil {
context.AddressManager().AddAddresses(peerAddress)
}
return peer, nil
}
// Handshake is different from other flows, since in it should forward router.ErrRouteClosed to errChan
// Therefore we implement a separate handleError for handshake
func handleError(err error, flowName string, isStopping *uint32, errChan chan error) {
if errors.Is(err, routerpkg.ErrRouteClosed) {
if atomic.AddUint32(isStopping, 1) == 1 {
errChan <- err
}
return
}
if protocolErr := &(protocolerrors.ProtocolError{}); errors.As(err, &protocolErr) {
log.Errorf("Handshake protocol error from %s: %s", flowName, err)
if atomic.AddUint32(isStopping, 1) == 1 {
errChan <- err
}
return
}
panic(err)
}