package respond import ( "bytes" "compress/flate" "encoding/json" "fmt" "log" "net" "time" "github.com/FreifunkBremen/yanic/data" "github.com/FreifunkBremen/yanic/database" "github.com/FreifunkBremen/yanic/jsontime" "github.com/FreifunkBremen/yanic/runtime" ) // Collector for a specificle respond messages type Collector struct { connection *net.UDPConn // UDP socket queue chan *Response // received responses iface string db database.Connection nodes *runtime.Nodes interval time.Duration // Interval for multicast packets stop chan interface{} } // NewCollector creates a Collector struct func NewCollector(db database.Connection, nodes *runtime.Nodes, iface string, port int) *Collector { linkLocalAddr, err := getLinkLocalAddr(iface) if err != nil { log.Panic(err) } // Open socket conn, err := net.ListenUDP("udp", &net.UDPAddr{ IP: linkLocalAddr, Port: port, Zone: iface, }) if err != nil { log.Panic(err) } conn.SetReadBuffer(maxDataGramSize) collector := &Collector{ connection: conn, db: db, nodes: nodes, iface: iface, queue: make(chan *Response, 400), stop: make(chan interface{}), } go collector.receiver() go collector.parser() if collector.db != nil { go collector.globalStatsWorker() } return collector } // Returns the first link local unicast address for the given interface name func getLinkLocalAddr(ifname string) (net.IP, error) { iface, err := net.InterfaceByName(ifname) if err != nil { return nil, err } addresses, err := iface.Addrs() if err != nil { return nil, err } for _, addr := range addresses { if ipnet := addr.(*net.IPNet); ipnet.IP.IsLinkLocalUnicast() { return ipnet.IP, nil } } return nil, fmt.Errorf("unable to find link local unicast address for %s", ifname) } // Start Collector func (coll *Collector) Start(interval time.Duration) { if coll.interval != 0 { panic("already started") } if interval <= 0 { panic("invalid collector interval") } coll.interval = interval go func() { coll.sendOnce() // immediately coll.sender() // periodically }() } // Close Collector func (coll *Collector) Close() { close(coll.stop) coll.connection.Close() close(coll.queue) } func (coll *Collector) sendOnce() { now := jsontime.Now() coll.sendMulticast() // Wait for the multicast responses to be processed and send unicasts time.Sleep(coll.interval / 2) coll.sendUnicasts(now) } func (coll *Collector) sendMulticast() { log.Println("sending multicast") coll.SendPacket(net.ParseIP(multiCastGroup)) } // Send unicast packets to nodes that did not answer the multicast func (coll *Collector) sendUnicasts(seenBefore jsontime.Time) { seenAfter := seenBefore.Add(-time.Minute * 10) // Select online nodes that has not been seen recently nodes := coll.nodes.Select(func(n *runtime.Node) bool { return n.Lastseen.After(seenAfter) && n.Lastseen.Before(seenBefore) && n.Address != nil }) // Send unicast packets log.Printf("sending unicast to %d nodes", len(nodes)) for _, node := range nodes { coll.SendPacket(node.Address) time.Sleep(10 * time.Millisecond) } } // SendPacket sends a UDP request to the given unicast or multicast address func (coll *Collector) SendPacket(address net.IP) { addr := net.UDPAddr{ IP: address, Port: port, Zone: coll.iface, } if _, err := coll.connection.WriteToUDP([]byte("GET nodeinfo statistics neighbours"), &addr); err != nil { log.Println("WriteToUDP failed:", err) } } // send packets continously func (coll *Collector) sender() { ticker := time.NewTicker(coll.interval) for { select { case <-coll.stop: ticker.Stop() return case <-ticker.C: // send the multicast packet to request per-node statistics coll.sendOnce() } } } func (coll *Collector) parser() { for obj := range coll.queue { if data, err := obj.parse(); err != nil { log.Println("unable to decode response from", obj.Address.String(), err, "\n", string(obj.Raw)) } else { coll.saveResponse(obj.Address, data) } } } func (res *Response) parse() (*data.ResponseData, error) { // Deflate deflater := flate.NewReader(bytes.NewReader(res.Raw)) defer deflater.Close() // Unmarshal rdata := &data.ResponseData{} err := json.NewDecoder(deflater).Decode(rdata) return rdata, err } func (coll *Collector) saveResponse(addr net.UDPAddr, res *data.ResponseData) { // Search for NodeID var nodeID string if val := res.NodeInfo; val != nil { nodeID = val.NodeID } else if val := res.Neighbours; val != nil { nodeID = val.NodeID } else if val := res.Statistics; val != nil { nodeID = val.NodeID } // Check length of nodeID if len(nodeID) != 12 { log.Printf("invalid NodeID '%s' from %s", nodeID, addr.String()) return } // Process the data and update IP address node := coll.nodes.Update(nodeID, res) node.Address = addr.IP // Store statistics in InfluxDB if coll.db != nil && node.Statistics != nil { coll.db.AddNode(nodeID, node) } } func (coll *Collector) receiver() { buf := make([]byte, maxDataGramSize) for { n, src, err := coll.connection.ReadFromUDP(buf) if err != nil { log.Println("ReadFromUDP failed:", err) return } raw := make([]byte, n) copy(raw, buf) coll.queue <- &Response{ Address: *src, Raw: raw, } } } func (coll *Collector) globalStatsWorker() { ticker := time.NewTicker(time.Minute) for { select { case <-coll.stop: ticker.Stop() return case <-ticker.C: coll.saveGlobalStats() } } } // saves global statistics func (coll *Collector) saveGlobalStats() { stats := runtime.NewGlobalStats(coll.nodes) coll.db.AddStatistics(stats, time.Now()) }