Files
stfs/pkg/recovery/fetch.go

151 lines
3.1 KiB
Go

package recovery
import (
"archive/tar"
"bufio"
"io"
"os"
"path/filepath"
"github.com/pojntfx/stfs/internal/compression"
"github.com/pojntfx/stfs/internal/converters"
models "github.com/pojntfx/stfs/internal/db/sqlite/models/metadata"
"github.com/pojntfx/stfs/internal/encryption"
"github.com/pojntfx/stfs/internal/mtio"
"github.com/pojntfx/stfs/internal/records"
"github.com/pojntfx/stfs/internal/signature"
"github.com/pojntfx/stfs/pkg/config"
)
func Fetch(
reader config.DriveReaderConfig,
drive config.DriveConfig,
pipes config.PipeConfig,
crypto config.CryptoConfig,
recordSize int,
record int,
block int,
to string,
preview bool,
onHeader func(hdr *models.Header),
) error {
var tr *tar.Reader
if reader.DriveIsRegular {
// Seek to record and block
if _, err := reader.Drive.Seek(int64((recordSize*mtio.BlockSize*record)+block*mtio.BlockSize), io.SeekStart); err != nil {
return err
}
tr = tar.NewReader(reader.Drive)
} else {
// Seek to record
if err := mtio.SeekToRecordOnTape(drive.Drive, int32(record)); err != nil {
return err
}
// Seek to block
br := bufio.NewReaderSize(drive.Drive, mtio.BlockSize*recordSize)
if _, err := br.Read(make([]byte, block*mtio.BlockSize)); err != nil {
return err
}
tr = tar.NewReader(br)
}
hdr, err := tr.Next()
if err != nil {
return err
}
if err := encryption.DecryptHeader(hdr, pipes.Encryption, crypto.Identity); err != nil {
return err
}
if err := signature.VerifyHeader(hdr, drive.DriveIsRegular, pipes.Signature, crypto.Recipient); err != nil {
return err
}
if onHeader != nil {
dbhdr, err := converters.TarHeaderToDBHeader(int64(record), -1, int64(block), -1, hdr)
if err != nil {
return err
}
onHeader(dbhdr)
}
if !preview {
if to == "" {
to = filepath.Base(hdr.Name)
}
if hdr.Typeflag == tar.TypeDir {
return os.MkdirAll(to, hdr.FileInfo().Mode())
}
dstFile, err := os.OpenFile(to, os.O_WRONLY|os.O_CREATE, hdr.FileInfo().Mode())
if err != nil {
return err
}
if err := dstFile.Truncate(0); err != nil {
return err
}
// Don't decompress non-regular files
if !hdr.FileInfo().Mode().IsRegular() {
if _, err := io.Copy(dstFile, tr); err != nil {
return err
}
return nil
}
decryptor, err := encryption.Decrypt(tr, pipes.Encryption, crypto.Identity)
if err != nil {
return err
}
decompressor, err := compression.Decompress(decryptor, pipes.Compression)
if err != nil {
return err
}
sig := ""
if hdr.PAXRecords != nil {
if s, ok := hdr.PAXRecords[records.STFSRecordSignature]; ok {
sig = s
}
}
verifier, verify, err := signature.Verify(decompressor, drive.DriveIsRegular, pipes.Signature, crypto.Recipient, sig)
if err != nil {
return err
}
if _, err := io.Copy(dstFile, verifier); err != nil {
return err
}
if err := verify(); err != nil {
return err
}
if err := decryptor.Close(); err != nil {
return err
}
if err := decompressor.Close(); err != nil {
return err
}
if err := dstFile.Close(); err != nil {
return err
}
}
return nil
}