diff --git a/cmd/restic/cmd_debug.go b/cmd/restic/cmd_debug.go index 3403b259a..80b94b980 100644 --- a/cmd/restic/cmd_debug.go +++ b/cmd/restic/cmd_debug.go @@ -7,6 +7,8 @@ import ( "encoding/json" "fmt" "io" + "os" + "sort" "github.com/spf13/cobra" @@ -42,6 +44,7 @@ Exit status is 0 if the command was successful, and non-zero if there was any er func init() { cmdRoot.AddCommand(cmdDebug) cmdDebug.AddCommand(cmdDebugDump) + cmdDebug.AddCommand(cmdDebugExamine) } func prettyPrintJSON(wr io.Writer, item interface{}) error { @@ -165,3 +168,177 @@ func runDebugDump(gopts GlobalOptions, args []string) error { return errors.Fatalf("no such type %q", tpe) } } + +var cmdDebugExamine = &cobra.Command{ + Use: "examine", + Short: "Examine a pack file", + DisableAutoGenTag: true, + RunE: func(cmd *cobra.Command, args []string) error { + return runDebugExamine(globalOptions, args) + }, +} + +func loadBlobs(ctx context.Context, repo restic.Repository, pack string, list []restic.PackedBlob) error { + be := repo.Backend() + for _, blob := range list { + fmt.Printf(" loading blob %v at %v (length %v)\n", blob.ID, blob.Offset, blob.Length) + buf := make([]byte, blob.Length) + h := restic.Handle{ + Name: pack, + Type: restic.PackFile, + } + err := be.Load(ctx, h, int(blob.Length), int64(blob.Offset), func(rd io.Reader) error { + n, err := io.ReadFull(rd, buf) + if err != nil { + fmt.Fprintf(os.Stderr, "read error after %d bytes: %v\n", n, err) + return err + } + return nil + }) + if err != nil { + fmt.Fprintf(os.Stderr, "error read: %v\n", err) + continue + } + + key := repo.Key() + + nonce, buf := buf[:key.NonceSize()], buf[key.NonceSize():] + buf, err = key.Open(buf[:0], nonce, buf, nil) + if err != nil { + fmt.Fprintf(os.Stderr, "error decrypting blob: %v\n", err) + continue + } + + id := restic.Hash(buf) + fmt.Printf(" successfully decrypted blob (length %v), hash is %v\n", len(buf), id) + if !id.Equal(blob.ID) { + fmt.Printf(" IDs do not match, want %v, got %v\n", blob.ID, id) + } else { + fmt.Printf(" IDs match\n") + } + } + + return nil +} + +func runDebugExamine(gopts GlobalOptions, args []string) error { + repo, err := OpenRepository(gopts) + if err != nil { + return err + } + + if !gopts.NoLock { + lock, err := lockRepo(gopts.ctx, repo) + defer unlockRepo(lock) + if err != nil { + return err + } + } + + err = repo.LoadIndex(gopts.ctx) + if err != nil { + return err + } + + for _, name := range args { + fmt.Printf("examine %v\n", name) + id, err := restic.ParseID(name) + if err != nil { + fmt.Fprintf(os.Stderr, "error: %v\n", err) + } + + h := restic.Handle{ + Type: restic.PackFile, + Name: name, + } + fi, err := repo.Backend().Stat(gopts.ctx, h) + if err != nil { + fmt.Fprintf(os.Stderr, "error: %v\n", err) + } + + fmt.Printf(" file size is %v\n", fi.Size) + + // examine all data the indexes have for the pack file + for _, idx := range repo.Index().(*repository.MasterIndex).All() { + idxIDs, err := idx.IDs() + if err != nil { + idxIDs = restic.IDs{} + } + + blobs := idx.ListPack(id) + if len(blobs) == 0 { + fmt.Printf(" index %v does not contain the file\n", idxIDs) + continue + } + + fmt.Printf(" index %v:\n", idxIDs) + + // track current size and offset + var size, offset uint64 + + sort.Slice(blobs, func(i, j int) bool { + return blobs[i].Offset < blobs[j].Offset + }) + + for _, pb := range blobs { + fmt.Printf(" %v blob %v, offset %-6d, raw length %-6d\n", pb.Type, pb.ID, pb.Offset, pb.Length) + if offset != uint64(pb.Offset) { + fmt.Printf(" hole in file, want offset %v, got %v\n", offset, pb.Offset) + } + offset += uint64(pb.Length) + size += uint64(pb.Length) + } + + // compute header size, per blob: 1 byte type, 4 byte length, 32 byte id + size += uint64(restic.CiphertextLength(len(blobs) * (1 + 4 + 32))) + // length in uint32 little endian + size += 4 + + if uint64(fi.Size) != size { + fmt.Printf(" file sizes do not match: computed %v from index, file size is %v\n", size, fi.Size) + } else { + fmt.Printf(" file sizes match\n") + } + + err = loadBlobs(gopts.ctx, repo, name, blobs) + if err != nil { + fmt.Fprintf(os.Stderr, "error: %v\n", err) + } + } + + // inspect the pack file itself + blobs, _, err := pack.List(repo.Key(), restic.ReaderAt(gopts.ctx, repo.Backend(), h), fi.Size) + if err != nil { + fmt.Fprintf(os.Stderr, "error for pack %v: %v\n", id.Str(), err) + return nil + } + + // track current size and offset + var size, offset uint64 + + sort.Slice(blobs, func(i, j int) bool { + return blobs[i].Offset < blobs[j].Offset + }) + + for _, pb := range blobs { + fmt.Printf(" %v blob %v, offset %-6d, raw length %-6d\n", pb.Type, pb.ID, pb.Offset, pb.Length) + if offset != uint64(pb.Offset) { + fmt.Printf(" hole in file, want offset %v, got %v\n", offset, pb.Offset) + } + offset += uint64(pb.Length) + size += uint64(pb.Length) + } + + // compute header size, per blob: 1 byte type, 4 byte length, 32 byte id + size += uint64(restic.CiphertextLength(len(blobs) * (1 + 4 + 32))) + // length in uint32 little endian + size += 4 + + if uint64(fi.Size) != size { + fmt.Printf(" file sizes do not match: computed %v from index, file size is %v\n", size, fi.Size) + } else { + fmt.Printf(" file sizes match\n") + } + } + return nil +}