cmd/torrentfs/main.go

   1 // Mounts a FUSE filesystem backed by torrents and magnet links.
   2 package main
   3
   4 import (
   5         "fmt"
   6         "net"
   7         "net/http"
   8         _ "net/http/pprof"
   9         "os"
  10         "os/signal"
  11         "os/user"
  12         "path/filepath"
  13         "syscall"
  14         "time"
  15
  16         "github.com/anacrolix/envpprof"
  17         _ "github.com/anacrolix/envpprof"
  18         "github.com/anacrolix/fuse"
  19         fusefs "github.com/anacrolix/fuse/fs"
  20         "github.com/anacrolix/log"
  21         "github.com/anacrolix/tagflag"
  22
  23         "github.com/anacrolix/torrent"
  24         torrentfs "github.com/anacrolix/torrent/fs"
  25         "github.com/anacrolix/torrent/util/dirwatch"
  26 )
  27
  28 var args = struct {
  29         MetainfoDir string `help:"torrent files in this location describe the contents of the mounted filesystem"`
  30         DownloadDir string `help:"location to save torrent data"`
  31         MountDir    string `help:"location the torrent contents are made available"`
  32
  33         DisableTrackers bool
  34         TestPeer        *net.TCPAddr
  35         ReadaheadBytes  tagflag.Bytes
  36         ListenAddr      *net.TCPAddr
  37 }{
  38         MetainfoDir: func() string {
  39                 _user, err := user.Current()
  40                 if err != nil {
  41                         panic(err)
  42                 }
  43                 return filepath.Join(_user.HomeDir, ".config/transmission/torrents")
  44         }(),
  45         ReadaheadBytes: 10 << 20,
  46         ListenAddr:     &net.TCPAddr{},
  47 }
  48
  49 func exitSignalHandlers(fs *torrentfs.TorrentFS) {
  50         c := make(chan os.Signal, 1)
  51         signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
  52         for {
  53                 <-c
  54                 fs.Destroy()
  55                 err := fuse.Unmount(args.MountDir)
  56                 if err != nil {
  57                         log.Print(err)
  58                 }
  59         }
  60 }
  61
  62 func addTestPeer(client *torrent.Client) {
  63         for _, t := range client.Torrents() {
  64                 t.AddPeers([]torrent.PeerInfo{{
  65                         Addr: args.TestPeer,
  66                 }})
  67         }
  68 }
  69
  70 func main() {
  71         defer envpprof.Stop()
  72         err := mainErr()
  73         if err != nil {
  74                 log.Printf("error in main: %v", err)
  75                 os.Exit(1)
  76         }
  77 }
  78
  79 func mainErr() error {
  80         tagflag.Parse(&args)
  81         if args.MountDir == "" {
  82                 os.Stderr.WriteString("y u no specify mountpoint?\n")
  83                 os.Exit(2)
  84         }
  85         conn, err := fuse.Mount(args.MountDir)
  86         if err != nil {
  87                 return fmt.Errorf("mounting: %w", err)
  88         }
  89         defer fuse.Unmount(args.MountDir)
  90         // TODO: Think about the ramifications of exiting not due to a signal.
  91         defer conn.Close()
  92         cfg := torrent.NewDefaultClientConfig()
  93         cfg.DataDir = args.DownloadDir
  94         cfg.DisableTrackers = args.DisableTrackers
  95         cfg.NoUpload = true // Ensure that downloads are responsive.
  96         cfg.SetListenAddr(args.ListenAddr.String())
  97         client, err := torrent.NewClient(cfg)
  98         if err != nil {
  99                 return fmt.Errorf("creating torrent client: %w", err)
 100         }
 101         // This is naturally exported via GOPPROF=http.
 102         http.DefaultServeMux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
 103                 client.WriteStatus(w)
 104         })
 105         dw, err := dirwatch.New(args.MetainfoDir)
 106         if err != nil {
 107                 return fmt.Errorf("watching torrent dir: %w", err)
 108         }
 109         dw.Logger = dw.Logger.FilterLevel(log.Info)
 110         go func() {
 111                 for ev := range dw.Events {
 112                         switch ev.Change {
 113                         case dirwatch.Added:
 114                                 if ev.TorrentFilePath != "" {
 115                                         _, err := client.AddTorrentFromFile(ev.TorrentFilePath)
 116                                         if err != nil {
 117                                                 log.Printf("error adding torrent from file %q to client: %v", ev.TorrentFilePath, err)
 118                                         }
 119                                 } else if ev.MagnetURI != "" {
 120                                         _, err := client.AddMagnet(ev.MagnetURI)
 121                                         if err != nil {
 122                                                 log.Printf("error adding magnet: %s", err)
 123                                         }
 124                                 }
 125                         case dirwatch.Removed:
 126                                 T, ok := client.Torrent(ev.InfoHash)
 127                                 if !ok {
 128                                         break
 129                                 }
 130                                 T.Drop()
 131                         }
 132                 }
 133         }()
 134         fs := torrentfs.New(client)
 135         go exitSignalHandlers(fs)
 136
 137         if args.TestPeer != nil {
 138                 go func() {
 139                         for {
 140                                 addTestPeer(client)
 141                                 time.Sleep(10 * time.Second)
 142                         }
 143                 }()
 144         }
 145
 146         if err := fusefs.Serve(conn, fs); err != nil {
 147                 return fmt.Errorf("serving fuse fs: %w", err)
 148         }
 149         <-conn.Ready
 150         if err := conn.MountError; err != nil {
 151                 return fmt.Errorf("mount error: %w", err)
 152         }
 153         return nil
 154 }