git.r.bdr.sh - rbdr/mobius/blob - hotline/transfer.go

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "io"
   8         "os"
   9         "path/filepath"
  10 )
  11
  12 type transfer struct {
  13         Protocol        [4]byte // "HTXF" 0x48545846
  14         ReferenceNumber [4]byte // Unique ID generated for the transfer
  15         DataSize        [4]byte // File size
  16         RSVD            [4]byte // Not implemented in Hotline Protocol
  17 }
  18
  19 var HTXF = [4]byte{0x48, 0x54, 0x58, 0x46} // (HTXF) is the only supported transfer protocol
  20
  21 func (tf *transfer) Write(b []byte) (int, error) {
  22         if err := binary.Read(bytes.NewReader(b), binary.BigEndian, tf); err != nil {
  23                 return 0, err
  24         }
  25
  26         if tf.Protocol != HTXF {
  27                 return 0, errors.New("invalid protocol")
  28         }
  29
  30         return len(b), nil
  31 }
  32
  33 func receiveFile(r io.Reader, targetFile, resForkFile, infoFork, counterWriter io.Writer) error {
  34         var ffo flattenedFileObject
  35         if _, err := ffo.ReadFrom(r); err != nil {
  36                 return err
  37         }
  38
  39         // Write the information fork
  40         _, err := io.Copy(infoFork, &ffo.FlatFileInformationFork)
  41         if err != nil {
  42                 return err
  43         }
  44
  45         if _, err = io.CopyN(targetFile, io.TeeReader(r, counterWriter), ffo.dataSize()); err != nil {
  46                 return err
  47         }
  48
  49         if ffo.FlatFileHeader.ForkCount == [2]byte{0, 3} {
  50                 if err := binary.Read(r, binary.BigEndian, &ffo.FlatFileResForkHeader); err != nil {
  51                         return err
  52                 }
  53
  54                 if _, err = io.CopyN(resForkFile, io.TeeReader(r, counterWriter), ffo.rsrcSize()); err != nil {
  55                         return err
  56                 }
  57         }
  58         return nil
  59 }
  60
  61 // TODO: read the banner once on startup instead of once per banner fetch
  62 func (s *Server) bannerDownload(w io.Writer) error {
  63         bannerBytes, err := os.ReadFile(filepath.Join(s.ConfigDir, s.Config.BannerFile))
  64         if err != nil {
  65                 return err
  66         }
  67         _, err = w.Write(bannerBytes)
  68
  69         return err
  70 }