tracker/udp.go

   1 package tracker
   2
   3 import (
   4         "context"
   5         "encoding/binary"
   6
   7         "github.com/anacrolix/generics"
   8
   9         trHttp "github.com/anacrolix/torrent/tracker/http"
  10         "github.com/anacrolix/torrent/tracker/udp"
  11         "github.com/anacrolix/torrent/types/infohash"
  12 )
  13
  14 type udpClient struct {
  15         cl         *udp.ConnClient
  16         requestUri string
  17 }
  18
  19 func (c *udpClient) Scrape(ctx context.Context, ihs []infohash.T) (out udp.ScrapeResponse, err error) {
  20         return c.cl.Client.Scrape(
  21                 ctx,
  22                 generics.SliceMap(ihs, func(from infohash.T) udp.InfoHash {
  23                         return from
  24                 }),
  25         )
  26 }
  27
  28 func (c *udpClient) Close() error {
  29         return c.cl.Close()
  30 }
  31
  32 func (c *udpClient) Announce(
  33         ctx context.Context,
  34         req AnnounceRequest,
  35         opts trHttp.AnnounceOpt,
  36 ) (res AnnounceResponse, err error) {
  37         if req.IPAddress == 0 && opts.ClientIp4 != nil {
  38                 // I think we're taking bytes in big-endian order (all IPs), and writing it to a natively
  39                 // ordered uint32. This will be correctly ordered when written back out by the UDP client
  40                 // later. I'm ignoring the fact that IPv6 announces shouldn't have an IP address, we have a
  41                 // perfectly good IPv4 address.
  42                 req.IPAddress = binary.BigEndian.Uint32(opts.ClientIp4.To4())
  43         }
  44         h, nas, err := c.cl.Announce(ctx, req, udp.Options{RequestUri: c.requestUri})
  45         if err != nil {
  46                 return
  47         }
  48         res.Interval = h.Interval
  49         res.Leechers = h.Leechers
  50         res.Seeders = h.Seeders
  51         for _, cp := range nas.NodeAddrs() {
  52                 res.Peers = append(res.Peers, trHttp.Peer{}.FromNodeAddr(cp))
  53         }
  54         return
  55 }