yanic/respond/collector.go

311 lines
7.1 KiB
Go

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 {
connections []*net.UDPConn // UDP sockets
ifaceToConn map[string]*net.UDPConn // map from interface name to UDP socket
port int
queue chan *Response // received responses
db database.Connection
nodes *runtime.Nodes
sites []string
interval time.Duration // Interval for multicast packets
stop chan interface{}
}
// NewCollector creates a Collector struct
func NewCollector(db database.Connection, nodes *runtime.Nodes, sites []string , ifaces []string, port int) *Collector {
coll := &Collector{
db: db,
nodes: nodes,
sites: sites,
port: port,
queue: make(chan *Response, 400),
stop: make(chan interface{}),
ifaceToConn: make(map[string]*net.UDPConn),
}
for _, iface := range ifaces {
coll.listenUDP(iface)
}
go coll.parser()
if coll.db != nil {
go coll.globalStatsWorker()
}
return coll
}
func (coll *Collector) listenUDP(iface string) {
if _, found := coll.ifaceToConn[iface]; found {
log.Panicf("can not listen twice on %s", iface)
}
linkLocalAddr, err := getLinkLocalAddr(iface)
if err != nil {
log.Panic(err)
}
// Open socket
conn, err := net.ListenUDP("udp", &net.UDPAddr{
IP: linkLocalAddr,
Port: coll.port,
Zone: iface,
})
if err != nil {
log.Panic(err)
}
conn.SetReadBuffer(maxDataGramSize)
coll.ifaceToConn[iface] = conn
coll.connections = append(coll.connections, conn)
// Start receiver
go coll.receiver(conn)
}
// 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)
for _, conn := range coll.connections {
conn.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 multicasts")
for _, conn := range coll.connections {
coll.sendPacket(conn, 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 {
conn := coll.ifaceToConn[node.Address.Zone]
if conn == nil {
log.Printf("unable to find connection for %s", node.Address.Zone)
continue
}
coll.sendPacket(conn, node.Address.IP)
time.Sleep(10 * time.Millisecond)
}
}
// SendPacket sends a UDP request to the given unicast or multicast address on the first UDP socket
func (coll *Collector) SendPacket(destination net.IP) {
coll.sendPacket(coll.connections[0], destination)
}
// sendPacket sends a UDP request to the given unicast or multicast address on the given UDP socket
func (coll *Collector) sendPacket(conn *net.UDPConn, destination net.IP) {
addr := net.UDPAddr{
IP: destination,
Port: port,
Zone: conn.LocalAddr().(*net.UDPAddr).Zone,
}
if _, err := conn.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
}
// Set fields to nil if nodeID is inconsistent
if res.Statistics != nil && res.Statistics.NodeID != nodeID {
res.Statistics = nil
}
if res.Neighbours != nil && res.Neighbours.NodeID != nodeID {
res.Neighbours = nil
}
if res.NodeInfo != nil && res.NodeInfo.NodeID != nodeID {
res.NodeInfo = nil
}
// Process the data and update IP address
node := coll.nodes.Update(nodeID, res)
node.Address = addr
// Store statistics in database
if db := coll.db; db != nil {
db.InsertNode(node)
// Store link data
if neighbours := node.Neighbours; neighbours != nil {
coll.nodes.RLock()
for _, link := range coll.nodes.NodeLinks(node) {
db.InsertLink(&link, node.Lastseen.GetTime())
}
coll.nodes.RUnlock()
}
}
}
func (coll *Collector) receiver(conn *net.UDPConn) {
buf := make([]byte, maxDataGramSize)
for {
n, src, err := conn.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.sites)
for site, stat := range stats {
coll.db.InsertGlobals(stat, time.Now(), site)
}
}