100 lines
1.6 KiB
Go
100 lines
1.6 KiB
Go
package main
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import (
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"log"
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"net"
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"sync"
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"time"
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"github.com/calmh/syncthing/discover"
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)
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type Node struct {
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IP []byte
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Port uint16
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Updated time.Time
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}
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var (
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nodes = make(map[string]Node)
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lock sync.Mutex
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queries = 0
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)
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func main() {
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addr, _ := net.ResolveUDPAddr("udp", ":22025")
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conn, err := net.ListenUDP("udp", addr)
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if err != nil {
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panic(err)
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}
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go func() {
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for {
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time.Sleep(600 * time.Second)
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lock.Lock()
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var deleted = 0
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for id, node := range nodes {
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if time.Since(node.Updated) > 60*time.Minute {
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delete(nodes, id)
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deleted++
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}
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}
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log.Printf("Expired %d nodes; %d nodes in registry; %d queries", deleted, len(nodes), queries)
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queries = 0
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lock.Unlock()
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}
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}()
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var buf = make([]byte, 1024)
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for {
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n, addr, err := conn.ReadFromUDP(buf)
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if err != nil {
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panic(err)
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}
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pkt, err := discover.DecodePacket(buf[:n])
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if err != nil {
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log.Println("Warning:", err)
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continue
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}
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switch pkt.Magic {
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case 0x20121025:
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// Announcement
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lock.Lock()
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ip := addr.IP.To4()
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if ip == nil {
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ip = addr.IP.To16()
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}
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node := Node{
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IP: ip,
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Port: uint16(pkt.Port),
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Updated: time.Now(),
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}
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//log.Println("<-", pkt.ID, node)
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nodes[pkt.ID] = node
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lock.Unlock()
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case 0x19760309:
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// Query
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lock.Lock()
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node, ok := nodes[pkt.ID]
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queries++
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lock.Unlock()
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if ok {
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pkt := discover.Packet{
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Magic: 0x20121025,
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ID: pkt.ID,
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Port: node.Port,
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IP: node.IP,
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}
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_, _, err = conn.WriteMsgUDP(discover.EncodePacket(pkt), nil, addr)
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if err != nil {
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log.Println("Warning:", err)
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}
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}
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}
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}
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}
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