protocol: add capabilities to version payload

closes #871

pkg/network/server.go

@@ -15,6 +15,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/blockchainer"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/network/capability"
 	"github.com/nspcc-dev/neo-go/pkg/network/payload"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"go.uber.org/atomic"
@@ -346,16 +347,42 @@ func (s *Server) HandshakedPeersCount() int {
 }
 
 // getVersionMsg returns current version message.
-func (s *Server) getVersionMsg() *Message {
+func (s *Server) getVersionMsg() (*Message, error) {
+	var port uint16
+	_, portStr, err := net.SplitHostPort(s.transport.Address())
+	if err != nil {
+		port = s.Port
+	} else {
+		p, err := strconv.ParseUint(portStr, 10, 16)
+		if err != nil {
+			return nil, err
+		}
+		port = uint16(p)
+	}
+
+	capabilities := []capability.Capability{
+		{
+			Type: capability.TCPServer,
+			Data: &capability.Server{
+				Port: port,
+			},
+		},
+	}
+	if s.Relay {
+		capabilities = append(capabilities, capability.Capability{
+			Type: capability.FullNode,
+			Data: &capability.Node{
+				StartHeight: s.chain.BlockHeight(),
+			},
+		})
+	}
 	payload := payload.NewVersion(
 		s.Net,
 		s.id,
-		s.Port,
 		s.UserAgent,
-		s.chain.BlockHeight(),
-		s.Relay,
+		capabilities,
 	)
-	return NewMessage(CMDVersion, payload)
+	return NewMessage(CMDVersion, payload), nil
 }
 
 // IsInSync answers the question of whether the server is in sync with the
@@ -835,9 +862,7 @@ func (s *Server) broadcastTxHashes(hs []util.Uint256) {
 
 	// We need to filter out non-relaying nodes, so plain broadcast
 	// functions don't fit here.
-	s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, func(p Peer) bool {
-		return p.Handshaked() && p.Version().Relay
-	})
+	s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, Peer.IsFullNode)
 }
 
 // broadcastTxLoop is a loop for batching and sending