Add support for Primary communication protocol (ethereum#333)

* Add support for Primary communication protocol

* Cleanup

* Cleanup

consensus/istanbul/backend/handler.go

@@ -42,6 +42,7 @@ func (sb *Backend) Protocol() consensus.Protocol {
 		Name:     "istanbul",
 		Versions: []uint{64},
 		Lengths:  []uint64{19},
+		Primary:  true,
 	}
 }
 

consensus/protocol.go

@@ -45,6 +45,8 @@ type Protocol struct {
 	Versions []uint
 	// Number of implemented message corresponding to different protocol versions.
 	Lengths []uint64
+	// Whether this should be the primary form of communication between nodes that support this protocol.
+	Primary bool
 }
 
 // Broadcaster defines the interface to enqueue blocks to fetcher and find peer

core/vm/evm.go

@@ -547,7 +547,7 @@ func (evm *EVM) ABIStaticCall(caller ContractRef, address common.Address, abi ab
 
 func (evm *EVM) ABICall(caller ContractRef, address common.Address, abi abi.ABI, funcName string, args []interface{}, returnObj interface{}, gas uint64, value *big.Int) (uint64, error) {
 	call := func(transactionData []byte) ([]byte, uint64, error) {
-		log.Trace("Performing call in the EVM", "caller", caller, "transactionData", hexutil.Encode(transactionData))
+		log.Trace("Performing call in the EVM", "caller", caller, "transactionData", hexutil.Encode(transactionData), "funcName", funcName)
 
 		return evm.Call(caller, address, transactionData, gas, value)
 	}

eth/handler.go

@@ -156,6 +156,7 @@ func NewProtocolManager(config *params.ChainConfig, mode downloader.SyncMode, ne
 			Name:    protocol.Name,
 			Version: version,
 			Length:  protocol.Lengths[i],
+			Primary: protocol.Primary,
 			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
 				peer := manager.newPeer(int(version), p, rw)
 				select {

p2p/peer.go

@@ -347,6 +347,17 @@ outer:
 			}
 		}
 	}
+
+	// If a primary protocol matched, return only that protocol.
+	for _, proto := range protocols {
+		if proto.Primary {
+			if _, ok := result[proto.Name]; ok {
+				primary := make(map[string]*protoRW)
+				primary[proto.Name] = result[proto.Name]
+				return primary
+			}
+		}
+	}
 	return result
 }
 

p2p/protocol.go

@@ -36,6 +36,9 @@ type Protocol struct {
 	// by the protocol.
 	Length uint64
 
+	// Whether this should be the primary form of communication between nodes that support this protocol.
+	Primary bool
+
 	// Run is called in a new goroutine when the protocol has been
 	// negotiated with a peer. It should read and write messages from
 	// rw. The Payload for each message must be fully consumed.

p2p/server.go

@@ -24,6 +24,7 @@ import (
 	"errors"
 	"net"
 	"sort"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -521,11 +522,18 @@ func (srv *Server) setupLocalNode() error {
 	srv.localnode.SetFallbackIP(net.IP{127, 0, 0, 1})
 	srv.localnode.Set(capsByNameAndVersion(srv.ourHandshake.Caps))
 	// TODO: check conflicts
+	var primaries []string
 	for _, p := range srv.Protocols {
+		if p.Primary {
+			primaries = append(primaries, p.Name)
+		}
 		for _, e := range p.Attributes {
 			srv.localnode.Set(e)
 		}
 	}
+	if len(primaries) > 1 {
+		srv.log.Crit("Multiple primary protocols specified", "names", strings.Join(primaries, ", "))
+	}
 	switch srv.NAT.(type) {
 	case nil:
 		// No NAT interface, do nothing.