package network import ( "errors" "sync" "time" "github.com/golang/protobuf/proto" "github.com/micro/go-micro/client" rtr "github.com/micro/go-micro/client/selector/router" pbNet "github.com/micro/go-micro/network/proto" "github.com/micro/go-micro/proxy" "github.com/micro/go-micro/router" pbRtr "github.com/micro/go-micro/router/proto" "github.com/micro/go-micro/server" "github.com/micro/go-micro/transport" "github.com/micro/go-micro/tunnel" tun "github.com/micro/go-micro/tunnel/transport" "github.com/micro/go-micro/util/log" ) var ( // NetworkChannel is the name of the tunnel channel for passing network messages NetworkChannel = "network" // ControlChannel is the name of the tunnel channel for passing control message ControlChannel = "control" // DefaultLink is default network link DefaultLink = "network" ) var ( // ErrClientNotFound is returned when client for tunnel channel could not be found ErrClientNotFound = errors.New("client not found") ) // network implements Network interface type network struct { // node is network node *node // options configure the network options Options // rtr is network router router.Router // prx is network proxy proxy.Proxy // tun is network tunnel tunnel.Tunnel // server is network server server server.Server // client is network client client client.Client // tunClient is a map of tunnel clients keyed over tunnel channel names tunClient map[string]transport.Client sync.RWMutex // connected marks the network as connected connected bool // closed closes the network closed chan bool } // newNetwork returns a new network node func newNetwork(opts ...Option) Network { options := DefaultOptions() for _, o := range opts { o(&options) } // init tunnel address to the network bind address options.Tunnel.Init( tunnel.Address(options.Address), tunnel.Nodes(options.Nodes...), ) // init router Id to the network id options.Router.Init( router.Id(options.Id), ) // create tunnel client with tunnel transport tunTransport := tun.NewTransport( tun.WithTunnel(options.Tunnel), ) // server is network server server := server.NewServer( server.Id(options.Id), server.Address(options.Address), server.Name(options.Name), server.Transport(tunTransport), ) // client is network client client := client.NewClient( client.Transport(tunTransport), client.Selector( rtr.NewSelector( rtr.WithRouter(options.Router), ), ), ) network := &network{ node: &node{ id: options.Id, address: options.Address, peers: make(map[string]*node), }, options: options, Router: options.Router, Proxy: options.Proxy, Tunnel: options.Tunnel, server: server, client: client, tunClient: make(map[string]transport.Client), } network.node.network = network return network } // Options returns network options func (n *network) Options() Options { n.RLock() defer n.RUnlock() options := n.options return options } // Name returns network name func (n *network) Name() string { return n.options.Name } // Address returns network bind address func (n *network) Address() string { return n.Tunnel.Address() } // resolveNodes resolves network nodes to addresses func (n *network) resolveNodes() ([]string, error) { // resolve the network address to network nodes records, err := n.options.Resolver.Resolve(n.options.Name) if err != nil { return nil, err } nodeMap := make(map[string]bool) // collect network node addresses var nodes []string for _, record := range records { nodes = append(nodes, record.Address) nodeMap[record.Address] = true } // append seed nodes if we have them for _, node := range n.options.Nodes { if _, ok := nodeMap[node]; !ok { nodes = append(nodes, node) } } return nodes, nil } // resolve continuously resolves network nodes and initializes network tunnel with resolved addresses func (n *network) resolve() { resolve := time.NewTicker(ResolveTime) defer resolve.Stop() for { select { case <-n.closed: return case <-resolve.C: nodes, err := n.resolveNodes() if err != nil { log.Debugf("Network failed to resolve nodes: %v", err) continue } // initialize the tunnel n.Tunnel.Init( tunnel.Nodes(nodes...), ) } } } // handleNetConn handles network announcement messages func (n *network) handleNetConn(sess tunnel.Session, msg chan *transport.Message) { for { m := new(transport.Message) if err := sess.Recv(m); err != nil { log.Debugf("Network tunnel [%s] receive error: %v", NetworkChannel, err) return } select { case msg <- m: case <-n.closed: return } } } // acceptNetConn accepts connections from NetworkChannel func (n *network) acceptNetConn(l tunnel.Listener, recv chan *transport.Message) { for { // accept a connection conn, err := l.Accept() if err != nil { // TODO: handle this log.Debugf("Network tunnel [%s] accept error: %v", NetworkChannel, err) return } select { case <-n.closed: return default: // go handle NetworkChannel connection go n.handleNetConn(conn, recv) } } } // processNetChan processes messages received on NetworkChannel func (n *network) processNetChan(client transport.Client, listener tunnel.Listener) { // receive network message queue recv := make(chan *transport.Message, 128) // accept NetworkChannel connections go n.acceptNetConn(listener, recv) for { select { case m := <-recv: // switch on type of message and take action switch m.Header["Micro-Method"] { case "connect": // mark the time the message has been received now := time.Now() pbNetConnect := &pbNet.Connect{} if err := proto.Unmarshal(m.Body, pbNetConnect); err != nil { log.Debugf("Network tunnel [%s] connect unmarshal error: %v", NetworkChannel, err) continue } // don't process your own messages if pbNetConnect.Node.Id == n.options.Id { continue } log.Debugf("Network received connect message from: %s", pbNetConnect.Node.Id) peer := &node{ id: pbNetConnect.Node.Id, address: pbNetConnect.Node.Address, peers: make(map[string]*node), lastSeen: now, } if ok := n.node.AddPeer(peer); !ok { log.Debugf("Network peer exists, refreshing: %s", peer.id) // update lastSeen time for the existing node if ok := n.RefreshPeer(peer.id, now); !ok { log.Debugf("Network failed refreshing peer: %s", peer.id) } continue } // get node peers down to MaxDepth encoded in protobuf msg := PeersToProto(n.node, MaxDepth) // advertise yourself to the network if err := n.sendMsg("peer", msg, NetworkChannel); err != nil { log.Debugf("Network failed to advertise peers: %v", err) } // advertise all the routes when a new node has connected if err := n.Router.Solicit(); err != nil { log.Debugf("Network failed to solicit routes: %s", err) } case "peer": // mark the time the message has been received now := time.Now() pbNetPeer := &pbNet.Peer{} if err := proto.Unmarshal(m.Body, pbNetPeer); err != nil { log.Debugf("Network tunnel [%s] peer unmarshal error: %v", NetworkChannel, err) continue } // don't process your own messages if pbNetPeer.Node.Id == n.options.Id { continue } log.Debugf("Network received peer message from: %s", pbNetPeer.Node.Id) peer := &node{ id: pbNetPeer.Node.Id, address: pbNetPeer.Node.Address, peers: make(map[string]*node), lastSeen: now, } if ok := n.node.AddPeer(peer); ok { // send a solicit message when discovering new peer msg := &pbRtr.Solicit{ Id: n.options.Id, } if err := n.sendMsg("solicit", msg, ControlChannel); err != nil { log.Debugf("Network failed to send solicit message: %s", err) } continue } log.Debugf("Network peer exists, refreshing: %s", pbNetPeer.Node.Id) // update lastSeen time for the peer if ok := n.RefreshPeer(pbNetPeer.Node.Id, now); !ok { log.Debugf("Network failed refreshing peer: %s", pbNetPeer.Node.Id) } // NOTE: we don't unpack MaxDepth toplogy peer = UnpackPeerTopology(pbNetPeer, now, MaxDepth-1) log.Debugf("Network updating topology of node: %s", n.node.id) if ok := n.node.UpdatePeer(peer); !ok { log.Debugf("Network failed to update peers") } case "close": pbNetClose := &pbNet.Close{} if err := proto.Unmarshal(m.Body, pbNetClose); err != nil { log.Debugf("Network tunnel [%s] close unmarshal error: %v", NetworkChannel, err) continue } // don't process your own messages if pbNetClose.Node.Id == n.options.Id { continue } log.Debugf("Network received close message from: %s", pbNetClose.Node.Id) if err := n.pruneNode(pbNetClose.Node.Id); err != nil { log.Debugf("Network failed to prune the node %s: %v", pbNetClose.Node.Id, err) continue } } case <-n.closed: return } } } // sendMsg sends a message to the tunnel channel func (n *network) sendMsg(method string, msg proto.Message, channel string) error { body, err := proto.Marshal(msg) if err != nil { return err } // create transport message and chuck it down the pipe m := transport.Message{ Header: map[string]string{ "Micro-Method": method, }, Body: body, } // check if the channel client is initialized n.RLock() client, ok := n.tunClient[channel] if !ok || client == nil { n.RUnlock() return ErrClientNotFound } n.RUnlock() log.Debugf("Network sending %s message from: %s", method, n.options.Id) if err := client.Send(&m); err != nil { return err } return nil } // announce announces node peers to the network func (n *network) announce(client transport.Client) { announce := time.NewTicker(AnnounceTime) defer announce.Stop() for { select { case <-n.closed: return case <-announce.C: msg := PeersToProto(n.node, MaxDepth) // advertise yourself to the network if err := n.sendMsg("peer", msg, NetworkChannel); err != nil { log.Debugf("Network failed to advertise peers: %v", err) continue } } } } // pruneNode removes a node with given id from the list of peers. It also removes all routes originted by this node. func (n *network) pruneNode(id string) error { // DeletePeer serializes access n.node.DeletePeer(id) // lookup all the routes originated at this node q := router.NewQuery( router.QueryRouter(id), ) routes, err := n.Router.Table().Query(q) if err != nil && err != router.ErrRouteNotFound { return err } // delete the found routes log.Logf("Network deleting routes originated by router: %s", id) for _, route := range routes { if err := n.Router.Table().Delete(route); err != nil && err != router.ErrRouteNotFound { return err } } return nil } // prune the nodes that have not been seen for certain period of time defined by PruneTime // Additionally, prune also removes all the routes originated by these nodes func (n *network) prune() { prune := time.NewTicker(PruneTime) defer prune.Stop() for { select { case <-n.closed: return case <-prune.C: n.Lock() for id, node := range n.peers { if id == n.options.Id { continue } if time.Since(node.lastSeen) > PruneTime { log.Debugf("Network deleting node %s: reached prune time threshold", id) if err := n.pruneNode(id); err != nil { log.Debugf("Network failed to prune the node %s: %v", id, err) continue } } } n.Unlock() } } } // handleCtrlConn handles ControlChannel connections func (n *network) handleCtrlConn(sess tunnel.Session, msg chan *transport.Message) { for { m := new(transport.Message) if err := sess.Recv(m); err != nil { // TODO: should we bail here? log.Debugf("Network tunnel advert receive error: %v", err) return } select { case msg <- m: case <-n.closed: return } } } // acceptCtrlConn accepts connections from ControlChannel func (n *network) acceptCtrlConn(l tunnel.Listener, recv chan *transport.Message) { for { // accept a connection conn, err := l.Accept() if err != nil { // TODO: handle this log.Debugf("Network tunnel [%s] accept error: %v", ControlChannel, err) return } select { case <-n.closed: return default: // go handle ControlChannel connection go n.handleCtrlConn(conn, recv) } } } // setRouteMetric calculates metric of the route and updates it in place // - Local route metric is 1 // - Routes with ID of adjacent nodes are 10 // - Routes by peers of the advertiser are 100 // - Routes beyond your neighbourhood are 1000 func (n *network) setRouteMetric(route *router.Route) { // we are the origin of the route if route.Router == n.options.Id { route.Metric = 1 return } // check if the route origin is our peer if _, ok := n.peers[route.Router]; ok { route.Metric = 10 return } // check if the route origin is the peer of our peer for _, peer := range n.peers { for id := range peer.peers { if route.Router == id { route.Metric = 100 return } } } // the origin of the route is beyond our neighbourhood route.Metric = 1000 } // processCtrlChan processes messages received on ControlChannel func (n *network) processCtrlChan(client transport.Client, listener tunnel.Listener) { // receive control message queue recv := make(chan *transport.Message, 128) // accept ControlChannel cconnections go n.acceptCtrlConn(listener, recv) for { select { case m := <-recv: // switch on type of message and take action switch m.Header["Micro-Method"] { case "advert": pbRtrAdvert := &pbRtr.Advert{} if err := proto.Unmarshal(m.Body, pbRtrAdvert); err != nil { log.Debugf("Network fail to unmarshal advert message: %v", err) continue } // don't process your own messages if pbRtrAdvert.Id == n.options.Id { continue } log.Debugf("Network received advert message with %d events from: %s", len(pbRtrAdvert.Events), pbRtrAdvert.Id) // loookup advertising node in our peer topology advertNode := n.node.GetPeerNode(pbRtrAdvert.Id) if advertNode == nil { // if we can't find the node in our topology (MaxDepth) we skipp prcessing adverts log.Debugf("Network skipping advert message from unknown peer: %s", pbRtrAdvert.Id) continue } var events []*router.Event for _, event := range pbRtrAdvert.Events { // we know the advertising node is not the origin of the route if pbRtrAdvert.Id != event.Route.Router { // if the origin router is not the advertising node peer // we can't rule out potential routing loops so we bail here if peer := advertNode.GetPeerNode(event.Route.Router); peer == nil { log.Debugf("Network skipping advert message from peer: %s", pbRtrAdvert.Id) continue } } route := router.Route{ Service: event.Route.Service, Address: event.Route.Address, Gateway: event.Route.Gateway, Network: event.Route.Network, Router: event.Route.Router, Link: event.Route.Link, Metric: int(event.Route.Metric), } // set the route metric n.node.RLock() n.setRouteMetric(&route) n.node.RUnlock() // throw away metric bigger than 1000 if route.Metric > 1000 { log.Debugf("Network route metric %d dropping node: %s", route.Metric, route.Router) continue } // create router event e := &router.Event{ Type: router.EventType(event.Type), Timestamp: time.Unix(0, pbRtrAdvert.Timestamp), Route: route, } events = append(events, e) } // if no events are eligible for processing continue if len(events) == 0 { log.Debugf("Network no events to be processed by router: %s", n.options.Id) continue } // create an advert and process it advert := &router.Advert{ Id: pbRtrAdvert.Id, Type: router.AdvertType(pbRtrAdvert.Type), Timestamp: time.Unix(0, pbRtrAdvert.Timestamp), TTL: time.Duration(pbRtrAdvert.Ttl), Events: events, } log.Debugf("Network router processing advert: %s", advert.Id) if err := n.Router.Process(advert); err != nil { log.Debugf("Network failed to process advert %s: %v", advert.Id, err) } case "solicit": pbRtrSolicit := &pbRtr.Solicit{} if err := proto.Unmarshal(m.Body, pbRtrSolicit); err != nil { log.Debugf("Network fail to unmarshal solicit message: %v", err) continue } log.Debugf("Network received solicit message from: %s", pbRtrSolicit.Id) // ignore solicitation when requested by you if pbRtrSolicit.Id == n.options.Id { continue } log.Debugf("Network router flushing routes for: %s", pbRtrSolicit.Id) // advertise all the routes when a new node has connected if err := n.Router.Solicit(); err != nil { log.Debugf("Network failed to solicit routes: %s", err) } } case <-n.closed: return } } } // advertise advertises routes to the network func (n *network) advertise(client transport.Client, advertChan <-chan *router.Advert) { for { select { // process local adverts and randomly fire them at other nodes case advert := <-advertChan: // create a proto advert var events []*pbRtr.Event for _, event := range advert.Events { // NOTE: we override the Gateway and Link fields here route := &pbRtr.Route{ Service: event.Route.Service, Address: event.Route.Address, Gateway: n.options.Address, Network: event.Route.Network, Router: event.Route.Router, Link: DefaultLink, Metric: int64(event.Route.Metric), } e := &pbRtr.Event{ Type: pbRtr.EventType(event.Type), Timestamp: event.Timestamp.UnixNano(), Route: route, } events = append(events, e) } msg := &pbRtr.Advert{ Id: advert.Id, Type: pbRtr.AdvertType(advert.Type), Timestamp: advert.Timestamp.UnixNano(), Events: events, } if err := n.sendMsg("advert", msg, ControlChannel); err != nil { log.Debugf("Network failed to advertise routes: %v", err) continue } case <-n.closed: return } } } // Connect connects the network func (n *network) Connect() error { n.Lock() // return if already connected if n.connected { n.Unlock() return nil } // try to resolve network nodes nodes, err := n.resolveNodes() if err != nil { log.Debugf("Network failed to resolve nodes: %v", err) } // connect network tunnel if err := n.Tunnel.Connect(); err != nil { n.Unlock() return err } // initialize the tunnel to resolved nodes n.Tunnel.Init( tunnel.Nodes(nodes...), ) // dial into ControlChannel to send route adverts ctrlClient, err := n.Tunnel.Dial(ControlChannel, tunnel.DialMulticast()) if err != nil { n.Unlock() return err } n.tunClient[ControlChannel] = ctrlClient // listen on ControlChannel ctrlListener, err := n.Tunnel.Listen(ControlChannel) if err != nil { n.Unlock() return err } // dial into NetworkChannel to send network messages netClient, err := n.Tunnel.Dial(NetworkChannel, tunnel.DialMulticast()) if err != nil { n.Unlock() return err } n.tunClient[NetworkChannel] = netClient // listen on NetworkChannel netListener, err := n.Tunnel.Listen(NetworkChannel) if err != nil { n.Unlock() return err } // create closed channel n.closed = make(chan bool) // start the router if err := n.options.Router.Start(); err != nil { n.Unlock() return err } // start advertising routes advertChan, err := n.options.Router.Advertise() if err != nil { n.Unlock() return err } // start the server if err := n.server.Start(); err != nil { n.Unlock() return err } n.Unlock() // send connect message to NetworkChannel // NOTE: in theory we could do this as soon as // Dial to NetworkChannel succeeds, but instead // we initialize all other node resources first msg := &pbNet.Connect{ Node: &pbNet.Node{ Id: n.options.Id, Address: n.options.Address, }, } if err := n.sendMsg("connect", msg, NetworkChannel); err != nil { log.Debugf("Network failed to send connect message: %s", err) } // go resolving network nodes go n.resolve() // broadcast peers go n.announce(netClient) // prune stale nodes go n.prune() // listen to network messages go n.processNetChan(netClient, netListener) // advertise service routes go n.advertise(ctrlClient, advertChan) // accept and process routes go n.processCtrlChan(ctrlClient, ctrlListener) n.Lock() n.connected = true n.Unlock() return nil } func (n *network) close() error { // stop the server if err := n.server.Stop(); err != nil { return err } // stop the router if err := n.Router.Stop(); err != nil { return err } // close the tunnel if err := n.Tunnel.Close(); err != nil { return err } return nil } // Close closes network connection func (n *network) Close() error { n.Lock() if !n.connected { n.Unlock() return nil } select { case <-n.closed: n.Unlock() return nil default: // TODO: send close message to the network channel close(n.closed) // set connected to false n.connected = false // unlock the lock otherwise we'll deadlock sending the close n.Unlock() msg := &pbNet.Close{ Node: &pbNet.Node{ Id: n.options.Id, Address: n.options.Address, }, } if err := n.sendMsg("close", msg, NetworkChannel); err != nil { log.Debugf("Network failed to send close message: %s", err) } } return n.close() } // Client returns network client func (n *network) Client() client.Client { return n.client } // Server returns network server func (n *network) Server() server.Server { return n.server }