Implement getpeerinfo and getconnectedcount

We have a channel for queries and commands in server, where we pass in
args and the channel to reply from, let rpcserver use these interfaces
to provide the requistie information.

So far not all of the informaation is 100% correct, the syncpeer
information needs to be fetched from blockmanager, the subversion isn't
recorded and the number of bytes sent and recieved needs to be obtained
from btcwire. The rest should be correct.

peer.go

@@ -113,8 +113,8 @@ type peer struct {
 	addr               string
 	na                 *btcwire.NetAddress
 	timeConnected      time.Time
-	lastSend	   time.Time
-	lastRecv	   time.Time
+	lastSend           time.Time
+	lastRecv           time.Time
 	inbound            bool
 	connected          int32
 	disconnect         int32 // only to be used atomically

rpcserver.go

@@ -320,6 +320,7 @@ var handlers = map[string]commandHandler{
 	"getdifficulty":        handleGetDifficulty,
 	"getgenerate":          handleGetGenerate,
 	"gethashespersec":      handleGetHashesPerSec,
+	"getpeerinfo":          handleGetPeerInfo,
 	"getrawmempool":        handleGetRawMempool,
 	"getrawtransaction":    handleGetRawTransaction,
 	"sendrawtransaction":   handleSendRawTransaction,
@@ -434,8 +435,7 @@ func handleGetBlockHash(s *rpcServer, cmd btcjson.Cmd, walletNotification chan [
 
 // handleGetConnectionCount implements the getconnectioncount command.
 func handleGetConnectionCount(s *rpcServer, cmd btcjson.Cmd, walletNotification chan []byte) (interface{}, error) {
-	// TODO fillmein.
-	return 0, nil
+	return s.server.ConnectedCount(), nil
 }
 
 // handleGetDifficulty implements the getdifficulty command.
@@ -467,6 +467,11 @@ func handleGetHashesPerSec(s *rpcServer, cmd btcjson.Cmd, walletNotification cha
 	return 0, nil
 }
 
+// handleGetPeerInfo implements the getpeerinfo command.
+func handleGetPeerInfo(s *rpcServer, cmd btcjson.Cmd, walletNotification chan []byte) (interface{}, error) {
+	return	s.server.PeerInfo(), nil
+}
+
 // handleGetRawMempool implements the getrawmempool command.
 func handleGetRawMempool(s *rpcServer, cmd btcjson.Cmd, walletNotification chan []byte) (interface{}, error) {
 	hashes := s.server.txMemPool.TxShas()

server.go

@@ -60,6 +60,7 @@ type server struct {
 	donePeers     chan *peer
 	banPeers      chan *peer
 	wakeup        chan bool
+	query         chan interface{}
 	relayInv      chan *btcwire.InvVect
 	broadcast     chan broadcastMsg
 	wg            sync.WaitGroup
@@ -198,6 +199,75 @@ func (s *server) handleBroadcastMsg(peers *list.List, bmsg *broadcastMsg) {
 	}
 }
 
+type PeerInfo struct {
+	Addr           string
+	Services       btcwire.ServiceFlag
+	LastSend       time.Time
+	LastRecv       time.Time
+	BytesSent      int
+	BytesRecv      int
+	ConnTime       time.Time
+	Version        uint32
+	SubVer         string
+	Inbound        bool
+	StartingHeight int32
+	BanScore       int
+	SyncNode       bool
+}
+
+type getConnCountMsg struct {
+	reply chan int
+}
+
+type getPeerInfoMsg struct {
+	reply chan []*PeerInfo
+}
+
+
+func (s *server) handleQuery(querymsg interface{}, peers *list.List, bannedPeers map[string]time.Time) {
+	switch msg := querymsg.(type) {
+	case getConnCountMsg:
+		nconnected := 0
+		for e := peers.Front(); e != nil; e = e.Next() {
+			peer := e.Value.(*peer)
+			if peer.Connected() {
+				nconnected++
+			}
+		}
+
+		msg.reply <- nconnected
+	case getPeerInfoMsg:
+		infos := make([]*PeerInfo, 0, peers.Len())
+		for e := peers.Front(); e != nil; e = e.Next() {
+			peer := e.Value.(*peer)
+			if !peer.Connected() {
+				continue
+			}
+			// A lot of this will make the race detector go mad,
+			// however it is statistics for purely informational purposes
+			// and we don't really care if they are raced to get the new
+			// version.
+			info := &PeerInfo{
+				Addr:           peer.addr,
+				Services:       peer.services,
+				LastSend:       peer.lastSend,
+				LastRecv:       peer.lastRecv,
+				BytesSent:      0, // TODO(oga) we need this from wire.
+				BytesRecv:      0, // TODO(oga) we need this from wire.
+				ConnTime:       peer.timeConnected,
+				Version:        peer.protocolVersion,
+				SubVer:         "unknown",
+				Inbound:        peer.inbound,
+				StartingHeight: peer.lastBlock,
+				BanScore:       0,
+				SyncNode:       false, // TODO(oga) for now. bm knows this.
+			}
+			infos = append(infos, info)
+		}
+		msg.reply <- infos
+	}
+}
+
 // listenHandler is the main listener which accepts incoming connections for the
 // server.  It must be run as a goroutine.
 func (s *server) listenHandler(listener net.Listener) {
@@ -332,6 +402,9 @@ out:
 		case <-s.wakeup:
 			// this page left intentionally blank
 
+		case qmsg := <-s.query:
+			s.handleQuery(qmsg, peers, bannedPeers)
+
 		// Shutdown the peer handler.
 		case <-s.quit:
 			// Shutdown peers.
@@ -456,6 +529,22 @@ func (s *server) BroadcastMessage(msg btcwire.Message, exclPeers ...*peer) {
 	s.broadcast <- bmsg
 }
 
+func (s *server) ConnectedCount() int {
+	replyChan := make(chan int)
+
+	s.query <- getConnCountMsg{reply: replyChan}
+
+	return <-replyChan
+}
+
+func (s *server) PeerInfo() []*PeerInfo {
+	replyChan := make(chan []*PeerInfo)
+
+	s.query <- getPeerInfoMsg{reply: replyChan}
+
+	return <-replyChan
+}
+
 // Start begins accepting connections from peers.
 func (s *server) Start() {
 	// Already started?
@@ -594,6 +683,7 @@ func newServer(addr string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*server, er
 		donePeers:   make(chan *peer, cfg.MaxPeers),
 		banPeers:    make(chan *peer, cfg.MaxPeers),
 		wakeup:      make(chan bool),
+		query:       make(chan interface{}),
 		relayInv:    make(chan *btcwire.InvVect, cfg.MaxPeers),
 		broadcast:   make(chan broadcastMsg, cfg.MaxPeers),
 		quit:        make(chan bool),