148 lines
3 KiB
Go
148 lines
3 KiB
Go
// Copyright 2015 The Chihaya Authors. All rights reserved.
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// Use of this source code is governed by the BSD 2-Clause license,
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// which can be found in the LICENSE file.
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// Package udp implements a BitTorrent tracker over the UDP protocol as per
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// BEP 15.
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package udp
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import (
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"errors"
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"net"
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"sync"
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"time"
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"github.com/golang/glog"
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"github.com/pushrax/bufferpool"
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"github.com/chihaya/chihaya/config"
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"github.com/chihaya/chihaya/tracker"
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)
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// Server represents a UDP torrent tracker.
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type Server struct {
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config *config.Config
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tracker *tracker.Tracker
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sock *net.UDPConn
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connIDGen *ConnectionIDGenerator
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closing chan struct{}
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booting chan struct{}
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wg sync.WaitGroup
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}
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func (s *Server) serve() error {
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if s.sock != nil {
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return errors.New("server already booted")
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}
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udpAddr, err := net.ResolveUDPAddr("udp", s.config.UDPConfig.ListenAddr)
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if err != nil {
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close(s.booting)
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return err
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}
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sock, err := net.ListenUDP("udp", udpAddr)
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if err != nil {
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close(s.booting)
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return err
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}
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defer sock.Close()
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if s.config.UDPConfig.ReadBufferSize > 0 {
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sock.SetReadBuffer(s.config.UDPConfig.ReadBufferSize)
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}
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pool := bufferpool.New(1000, 2048)
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s.sock = sock
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close(s.booting)
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for {
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select {
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case <-s.closing:
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return nil
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default:
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}
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buffer := pool.TakeSlice()
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sock.SetReadDeadline(time.Now().Add(time.Second))
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n, addr, err := sock.ReadFromUDP(buffer)
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if err != nil {
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if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
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pool.GiveSlice(buffer)
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continue
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}
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return err
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}
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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start := time.Now()
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response, action, err := s.handlePacket(buffer[:n], addr)
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defer pool.GiveSlice(buffer)
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duration := time.Since(start)
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if len(response) > 0 {
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sock.WriteToUDP(response, addr)
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}
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if glog.V(2) {
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if err != nil {
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glog.Infof("[UDP - %9s] %s %s (%s)", duration, action, addr, err)
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} else {
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glog.Infof("[UDP - %9s] %s %s", duration, action, addr)
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}
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}
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}()
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}
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return nil
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}
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// Serve runs a UDP server, blocking until the server has shut down.
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func (s *Server) Serve() {
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glog.V(0).Info("Starting UDP on ", s.config.UDPConfig.ListenAddr)
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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for {
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select {
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case <-s.closing:
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return
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case <-time.After(time.Hour):
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s.connIDGen.NewIV()
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}
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}
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}()
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if err := s.serve(); err != nil {
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glog.Errorf("Failed to run UDP server: %s", err.Error())
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} else {
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glog.Info("UDP server shut down cleanly")
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}
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}
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// Stop cleanly shuts down the server.
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func (s *Server) Stop() {
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close(s.closing)
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s.sock.SetReadDeadline(time.Now())
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s.wg.Wait()
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}
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// NewServer returns a new UDP server for a given configuration and tracker.
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func NewServer(cfg *config.Config, tkr *tracker.Tracker) *Server {
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gen, err := NewConnectionIDGenerator()
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if err != nil {
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panic(err)
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}
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return &Server{
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config: cfg,
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tracker: tkr,
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connIDGen: gen,
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closing: make(chan struct{}),
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booting: make(chan struct{}),
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}
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}
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