torrent/cmd/torrent-verify/main.go

86 lines
1.8 KiB
Go

package main
import (
"bytes"
"crypto/sha1"
"fmt"
"io"
"log"
"os"
"path/filepath"
"github.com/anacrolix/tagflag"
"github.com/edsrzf/mmap-go"
"github.com/anacrolix/torrent/metainfo"
"github.com/anacrolix/torrent/mmap_span"
)
func mmapFile(name string) (mm mmap.MMap, err error) {
f, err := os.Open(name)
if err != nil {
return
}
defer f.Close()
fi, err := f.Stat()
if err != nil {
return
}
if fi.Size() == 0 {
return
}
return mmap.MapRegion(f, -1, mmap.RDONLY, mmap.COPY, 0)
}
func verifyTorrent(info *metainfo.Info, root string) error {
span := new(mmap_span.MMapSpan)
for _, file := range info.UpvertedFiles() {
filename := filepath.Join(append([]string{root, info.Name}, file.Path...)...)
mm, err := mmapFile(filename)
if err != nil {
return err
}
if int64(len(mm)) != file.Length {
return fmt.Errorf("file %q has wrong length", filename)
}
span.Append(mm)
}
span.InitIndex()
for i, numPieces := 0, info.NumPieces(); i < numPieces; i += 1 {
p := info.Piece(i)
hash := sha1.New()
_, err := io.Copy(hash, io.NewSectionReader(span, p.Offset(), p.Length()))
if err != nil {
return err
}
good := bytes.Equal(hash.Sum(nil), p.Hash().Bytes())
if !good {
return fmt.Errorf("hash mismatch at piece %d", i)
}
fmt.Printf("%d: %v: %v\n", i, p.Hash(), good)
}
return nil
}
func main() {
log.SetFlags(log.Flags() | log.Lshortfile)
flags := struct {
DataDir string
tagflag.StartPos
TorrentFile string
}{}
tagflag.Parse(&flags)
metaInfo, err := metainfo.LoadFromFile(flags.TorrentFile)
if err != nil {
log.Fatal(err)
}
info, err := metaInfo.UnmarshalInfo()
if err != nil {
log.Fatalf("error unmarshalling info: %s", err)
}
err = verifyTorrent(&info, flags.DataDir)
if err != nil {
log.Fatalf("torrent failed verification: %s", err)
}
}