tracker/http.go

   1 package tracker
   2
   3 import (
   4         "bytes"
   5         "crypto/tls"
   6         "fmt"
   7         "io"
   8         "net"
   9         "net/http"
  10         "net/url"
  11         "strconv"
  12         "time"
  13
  14         "github.com/anacrolix/dht/krpc"
  15         "github.com/anacrolix/missinggo/httptoo"
  16
  17         "github.com/anacrolix/torrent/bencode"
  18 )
  19
  20 type httpResponse struct {
  21         FailureReason string `bencode:"failure reason"`
  22         Interval      int32  `bencode:"interval"`
  23         TrackerId     string `bencode:"tracker id"`
  24         Complete      int32  `bencode:"complete"`
  25         Incomplete    int32  `bencode:"incomplete"`
  26         Peers         Peers  `bencode:"peers"`
  27         // BEP 7
  28         Peers6 krpc.CompactIPv6NodeAddrs `bencode:"peers6"`
  29 }
  30
  31 type Peers []Peer
  32
  33 func (me *Peers) UnmarshalBencode(b []byte) (err error) {
  34         var _v interface{}
  35         err = bencode.Unmarshal(b, &_v)
  36         if err != nil {
  37                 return
  38         }
  39         switch v := _v.(type) {
  40         case string:
  41                 vars.Add("http responses with string peers", 1)
  42                 var cnas krpc.CompactIPv4NodeAddrs
  43                 err = cnas.UnmarshalBinary([]byte(v))
  44                 if err != nil {
  45                         return
  46                 }
  47                 for _, cp := range cnas {
  48                         *me = append(*me, Peer{
  49                                 IP:   cp.IP[:],
  50                                 Port: int(cp.Port),
  51                         })
  52                 }
  53                 return
  54         case []interface{}:
  55                 vars.Add("http responses with list peers", 1)
  56                 for _, i := range v {
  57                         var p Peer
  58                         p.fromDictInterface(i.(map[string]interface{}))
  59                         *me = append(*me, p)
  60                 }
  61                 return
  62         default:
  63                 vars.Add("http responses with unhandled peers type", 1)
  64                 err = fmt.Errorf("unsupported type: %T", _v)
  65                 return
  66         }
  67 }
  68
  69 func setAnnounceParams(_url *url.URL, ar *AnnounceRequest, opts Announce) {
  70         q := _url.Query()
  71
  72         q.Set("info_hash", string(ar.InfoHash[:]))
  73         q.Set("peer_id", string(ar.PeerId[:]))
  74         // AFAICT, port is mandatory, and there's no implied port key.
  75         q.Set("port", fmt.Sprintf("%d", ar.Port))
  76         q.Set("uploaded", strconv.FormatInt(ar.Uploaded, 10))
  77         q.Set("downloaded", strconv.FormatInt(ar.Downloaded, 10))
  78         q.Set("left", strconv.FormatUint(ar.Left, 10))
  79         if ar.Event != None {
  80                 q.Set("event", ar.Event.String())
  81         }
  82         // http://stackoverflow.com/questions/17418004/why-does-tracker-server-not-understand-my-request-bittorrent-protocol
  83         q.Set("compact", "1")
  84         // According to https://wiki.vuze.com/w/Message_Stream_Encryption. TODO:
  85         // Take EncryptionPolicy or something like it as a parameter.
  86         q.Set("supportcrypto", "1")
  87         if opts.ClientIp4.IP != nil {
  88                 q.Set("ipv4", opts.ClientIp4.String())
  89         }
  90         if opts.ClientIp6.IP != nil {
  91                 q.Set("ipv6", opts.ClientIp6.String())
  92         }
  93         _url.RawQuery = q.Encode()
  94 }
  95
  96 func announceHTTP(opt Announce, _url *url.URL) (ret AnnounceResponse, err error) {
  97         _url = httptoo.CopyURL(_url)
  98         setAnnounceParams(_url, &opt.Request, opt)
  99         req, err := http.NewRequest("GET", _url.String(), nil)
 100         req.Header.Set("User-Agent", opt.UserAgent)
 101         req.Host = opt.HostHeader
 102         resp, err := (&http.Client{
 103                 Timeout: time.Second * 15,
 104                 Transport: &http.Transport{
 105                         Dial: (&net.Dialer{
 106                                 Timeout: 15 * time.Second,
 107                         }).Dial,
 108                         Proxy:               opt.HTTPProxy,
 109                         TLSHandshakeTimeout: 15 * time.Second,
 110                         TLSClientConfig: &tls.Config{
 111                                 InsecureSkipVerify: true,
 112                                 ServerName:         opt.ServerName,
 113                         },
 114                 },
 115         }).Do(req)
 116         if err != nil {
 117                 return
 118         }
 119         defer resp.Body.Close()
 120         var buf bytes.Buffer
 121         io.Copy(&buf, resp.Body)
 122         if resp.StatusCode != 200 {
 123                 err = fmt.Errorf("response from tracker: %s: %s", resp.Status, buf.String())
 124                 return
 125         }
 126         var trackerResponse httpResponse
 127         err = bencode.Unmarshal(buf.Bytes(), &trackerResponse)
 128         if _, ok := err.(bencode.ErrUnusedTrailingBytes); ok {
 129                 err = nil
 130         } else if err != nil {
 131                 err = fmt.Errorf("error decoding %q: %s", buf.Bytes(), err)
 132                 return
 133         }
 134         if trackerResponse.FailureReason != "" {
 135                 err = fmt.Errorf("tracker gave failure reason: %q", trackerResponse.FailureReason)
 136                 return
 137         }
 138         vars.Add("successful http announces", 1)
 139         ret.Interval = trackerResponse.Interval
 140         ret.Leechers = trackerResponse.Incomplete
 141         ret.Seeders = trackerResponse.Complete
 142         if len(trackerResponse.Peers) != 0 {
 143                 vars.Add("http responses with nonempty peers key", 1)
 144         }
 145         ret.Peers = trackerResponse.Peers
 146         if len(trackerResponse.Peers6) != 0 {
 147                 vars.Add("http responses with nonempty peers6 key", 1)
 148         }
 149         for _, na := range trackerResponse.Peers6 {
 150                 ret.Peers = append(ret.Peers, Peer{
 151                         IP:   na.IP,
 152                         Port: na.Port,
 153                 })
 154         }
 155         return
 156 }