src/tx.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2022 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 package nncp
  19
  20 import (
  21         "archive/tar"
  22         "bufio"
  23         "bytes"
  24         "errors"
  25         "fmt"
  26         "io"
  27         "os"
  28         "path/filepath"
  29         "strconv"
  30         "strings"
  31         "time"
  32
  33         xdr "github.com/davecgh/go-xdr/xdr2"
  34         "github.com/dustin/go-humanize"
  35         "github.com/klauspost/compress/zstd"
  36         "golang.org/x/crypto/blake2b"
  37 )
  38
  39 const (
  40         MaxFileSize = 1 << 62
  41
  42         TarBlockSize = 512
  43         TarExt       = ".tar"
  44 )
  45
  46 type PktEncWriteResult struct {
  47         pktEncRaw []byte
  48         size      int64
  49         err       error
  50 }
  51
  52 func (ctx *Ctx) Tx(
  53         node *Node,
  54         pkt *Pkt,
  55         nice uint8,
  56         srcSize, minSize, maxSize int64,
  57         src io.Reader,
  58         pktName string,
  59         areaId *AreaId,
  60 ) (*Node, int64, error) {
  61         var area *Area
  62         if areaId != nil {
  63                 area = ctx.AreaId2Area[*areaId]
  64                 if area.Prv == nil {
  65                         return nil, 0, errors.New("area has no encryption keys")
  66                 }
  67         }
  68         hops := make([]*Node, 0, 1+len(node.Via))
  69         hops = append(hops, node)
  70         lastNode := node
  71         for i := len(node.Via); i > 0; i-- {
  72                 lastNode = ctx.Neigh[*node.Via[i-1]]
  73                 hops = append(hops, lastNode)
  74         }
  75         wrappers := len(hops)
  76         if area != nil {
  77                 wrappers++
  78         }
  79         var expectedSize int64
  80         if srcSize > 0 {
  81                 expectedSize = srcSize + PktOverhead
  82                 expectedSize += sizePadCalc(expectedSize, minSize, wrappers)
  83                 expectedSize = PktEncOverhead + sizeWithTags(expectedSize)
  84                 if maxSize != 0 && expectedSize > maxSize {
  85                         return nil, 0, TooBig
  86                 }
  87                 if !ctx.IsEnoughSpace(expectedSize) {
  88                         return nil, 0, errors.New("is not enough space")
  89                 }
  90         }
  91         tmp, err := ctx.NewTmpFileWHash()
  92         if err != nil {
  93                 return nil, 0, err
  94         }
  95
  96         results := make(chan PktEncWriteResult)
  97         pipeR, pipeW := io.Pipe()
  98         var pipeRPrev io.Reader
  99         if area == nil {
 100                 go func(src io.Reader, dst io.WriteCloser) {
 101                         ctx.LogD("tx", LEs{
 102                                 {"Node", hops[0].Id},
 103                                 {"Nice", int(nice)},
 104                                 {"Size", expectedSize},
 105                         }, func(les LEs) string {
 106                                 return fmt.Sprintf(
 107                                         "Tx packet to %s (source %s) nice: %s",
 108                                         ctx.NodeName(hops[0].Id),
 109                                         humanize.IBytes(uint64(expectedSize)),
 110                                         NicenessFmt(nice),
 111                                 )
 112                         })
 113                         pktEncRaw, size, err := PktEncWrite(
 114                                 ctx.Self, hops[0], pkt, nice, minSize, maxSize, wrappers, src, dst,
 115                         )
 116                         results <- PktEncWriteResult{pktEncRaw, size, err}
 117                         dst.Close()
 118                 }(src, pipeW)
 119         } else {
 120                 go func(src io.Reader, dst io.WriteCloser) {
 121                         ctx.LogD("tx", LEs{
 122                                 {"Area", area.Id},
 123                                 {"Nice", int(nice)},
 124                                 {"Size", expectedSize},
 125                         }, func(les LEs) string {
 126                                 return fmt.Sprintf(
 127                                         "Tx area packet to %s (source %s) nice: %s",
 128                                         ctx.AreaName(areaId),
 129                                         humanize.IBytes(uint64(expectedSize)),
 130                                         NicenessFmt(nice),
 131                                 )
 132                         })
 133                         areaNode := Node{Id: new(NodeId), ExchPub: new([32]byte)}
 134                         copy(areaNode.Id[:], area.Id[:])
 135                         copy(areaNode.ExchPub[:], area.Pub[:])
 136                         pktEncRaw, size, err := PktEncWrite(
 137                                 ctx.Self, &areaNode, pkt, nice, 0, maxSize, 0, src, dst,
 138                         )
 139                         results <- PktEncWriteResult{pktEncRaw, size, err}
 140                         dst.Close()
 141                 }(src, pipeW)
 142                 pipeRPrev = pipeR
 143                 pipeR, pipeW = io.Pipe()
 144                 go func(src io.Reader, dst io.WriteCloser) {
 145                         pktArea, err := NewPkt(PktTypeArea, 0, area.Id[:])
 146                         if err != nil {
 147                                 panic(err)
 148                         }
 149                         ctx.LogD("tx", LEs{
 150                                 {"Node", hops[0].Id},
 151                                 {"Nice", int(nice)},
 152                                 {"Size", expectedSize},
 153                         }, func(les LEs) string {
 154                                 return fmt.Sprintf(
 155                                         "Tx packet to %s (source %s) nice: %s",
 156                                         ctx.NodeName(hops[0].Id),
 157                                         humanize.IBytes(uint64(expectedSize)),
 158                                         NicenessFmt(nice),
 159                                 )
 160                         })
 161                         pktEncRaw, size, err := PktEncWrite(
 162                                 ctx.Self, hops[0], pktArea, nice, minSize, maxSize, wrappers, src, dst,
 163                         )
 164                         results <- PktEncWriteResult{pktEncRaw, size, err}
 165                         dst.Close()
 166                 }(pipeRPrev, pipeW)
 167         }
 168         for i := 1; i < len(hops); i++ {
 169                 pktTrns, err := NewPkt(PktTypeTrns, 0, hops[i-1].Id[:])
 170                 if err != nil {
 171                         panic(err)
 172                 }
 173                 pipeRPrev = pipeR
 174                 pipeR, pipeW = io.Pipe()
 175                 go func(node *Node, pkt *Pkt, src io.Reader, dst io.WriteCloser) {
 176                         ctx.LogD("tx", LEs{
 177                                 {"Node", node.Id},
 178                                 {"Nice", int(nice)},
 179                         }, func(les LEs) string {
 180                                 return fmt.Sprintf(
 181                                         "Tx trns packet to %s nice: %s",
 182                                         ctx.NodeName(node.Id),
 183                                         NicenessFmt(nice),
 184                                 )
 185                         })
 186                         pktEncRaw, size, err := PktEncWrite(
 187                                 ctx.Self, node, pkt, nice, 0, MaxFileSize, 0, src, dst,
 188                         )
 189                         results <- PktEncWriteResult{pktEncRaw, size, err}
 190                         dst.Close()
 191                 }(hops[i], pktTrns, pipeRPrev, pipeW)
 192         }
 193         go func() {
 194                 _, err := CopyProgressed(
 195                         tmp.W, pipeR, "Tx",
 196                         LEs{{"Pkt", pktName}, {"FullSize", expectedSize}},
 197                         ctx.ShowPrgrs,
 198                 )
 199                 results <- PktEncWriteResult{err: err}
 200         }()
 201         var pktEncRaw []byte
 202         var pktEncMsg []byte
 203         var payloadSize int64
 204         if area != nil {
 205                 r := <-results
 206                 payloadSize = r.size
 207                 pktEncMsg = r.pktEncRaw
 208                 wrappers--
 209         }
 210         for i := 0; i <= wrappers; i++ {
 211                 r := <-results
 212                 if r.err != nil {
 213                         tmp.Fd.Close()
 214                         return nil, 0, r.err
 215                 }
 216                 if r.pktEncRaw != nil {
 217                         pktEncRaw = r.pktEncRaw
 218                         if payloadSize == 0 {
 219                                 payloadSize = r.size
 220                         }
 221                 }
 222         }
 223         nodePath := filepath.Join(ctx.Spool, lastNode.Id.String())
 224         err = tmp.Commit(filepath.Join(nodePath, string(TTx)))
 225         os.Symlink(nodePath, filepath.Join(ctx.Spool, lastNode.Name))
 226         if err != nil {
 227                 return lastNode, 0, err
 228         }
 229         if ctx.HdrUsage {
 230                 ctx.HdrWrite(pktEncRaw, filepath.Join(nodePath, string(TTx), tmp.Checksum()))
 231         }
 232         if area != nil {
 233                 msgHashRaw := blake2b.Sum256(pktEncMsg)
 234                 msgHash := Base32Codec.EncodeToString(msgHashRaw[:])
 235                 seenDir := filepath.Join(
 236                         ctx.Spool, ctx.SelfId.String(), AreaDir, areaId.String(),
 237                 )
 238                 seenPath := filepath.Join(seenDir, msgHash)
 239                 les := LEs{
 240                         {"Node", node.Id},
 241                         {"Nice", int(nice)},
 242                         {"Size", expectedSize},
 243                         {"Area", areaId},
 244                         {"AreaMsg", msgHash},
 245                 }
 246                 logMsg := func(les LEs) string {
 247                         return fmt.Sprintf(
 248                                 "Tx area packet to %s (source %s) nice: %s, area %s: %s",
 249                                 ctx.NodeName(node.Id),
 250                                 humanize.IBytes(uint64(expectedSize)),
 251                                 NicenessFmt(nice),
 252                                 area.Name,
 253                                 msgHash,
 254                         )
 255                 }
 256                 if err = ensureDir(seenDir); err != nil {
 257                         ctx.LogE("tx-mkdir", les, err, logMsg)
 258                         return lastNode, 0, err
 259                 }
 260                 if fd, err := os.Create(seenPath); err == nil {
 261                         fd.Close()
 262                         if err = DirSync(seenDir); err != nil {
 263                                 ctx.LogE("tx-dirsync", les, err, logMsg)
 264                                 return lastNode, 0, err
 265                         }
 266                 }
 267                 ctx.LogI("tx-area", les, logMsg)
 268         }
 269         return lastNode, payloadSize, err
 270 }
 271
 272 type DummyCloser struct{}
 273
 274 func (dc DummyCloser) Close() error { return nil }
 275
 276 func prepareTxFile(srcPath string) (
 277         reader io.Reader,
 278         closer io.Closer,
 279         srcSize int64,
 280         archived bool,
 281         rerr error,
 282 ) {
 283         if srcPath == "-" {
 284                 reader = os.Stdin
 285                 closer = os.Stdin
 286                 return
 287         }
 288
 289         srcStat, err := os.Stat(srcPath)
 290         if err != nil {
 291                 rerr = err
 292                 return
 293         }
 294         mode := srcStat.Mode()
 295
 296         if mode.IsRegular() {
 297                 // It is regular file, just send it
 298                 src, err := os.Open(srcPath)
 299                 if err != nil {
 300                         rerr = err
 301                         return
 302                 }
 303                 reader = src
 304                 closer = src
 305                 srcSize = srcStat.Size()
 306                 return
 307         }
 308
 309         if !mode.IsDir() {
 310                 rerr = errors.New("unsupported file type")
 311                 return
 312         }
 313
 314         // It is directory, create PAX archive with its contents
 315         archived = true
 316         basePath := filepath.Base(srcPath)
 317         rootPath, err := filepath.Abs(srcPath)
 318         if err != nil {
 319                 rerr = err
 320                 return
 321         }
 322         type einfo struct {
 323                 path    string
 324                 modTime time.Time
 325                 size    int64
 326         }
 327         dirs := make([]einfo, 0, 1<<10)
 328         files := make([]einfo, 0, 1<<10)
 329         rerr = filepath.Walk(rootPath, func(path string, info os.FileInfo, err error) error {
 330                 if err != nil {
 331                         return err
 332                 }
 333                 if info.IsDir() {
 334                         // directory header, PAX record header+contents
 335                         srcSize += TarBlockSize + 2*TarBlockSize
 336                         dirs = append(dirs, einfo{path: path, modTime: info.ModTime()})
 337                 } else {
 338                         // file header, PAX record header+contents, file content
 339                         srcSize += TarBlockSize + 2*TarBlockSize + info.Size()
 340                         if n := info.Size() % TarBlockSize; n != 0 {
 341                                 srcSize += TarBlockSize - n // padding
 342                         }
 343                         files = append(files, einfo{
 344                                 path:    path,
 345                                 modTime: info.ModTime(),
 346                                 size:    info.Size(),
 347                         })
 348                 }
 349                 return nil
 350         })
 351         if rerr != nil {
 352                 return
 353         }
 354
 355         r, w := io.Pipe()
 356         reader = r
 357         closer = DummyCloser{}
 358         srcSize += 2 * TarBlockSize // termination block
 359
 360         go func() error {
 361                 tarWr := tar.NewWriter(w)
 362                 hdr := tar.Header{
 363                         Typeflag: tar.TypeDir,
 364                         Mode:     0777,
 365                         PAXRecords: map[string]string{
 366                                 "comment": "Autogenerated by " + VersionGet(),
 367                         },
 368                         Format: tar.FormatPAX,
 369                 }
 370                 for _, e := range dirs {
 371                         hdr.Name = basePath + e.path[len(rootPath):]
 372                         hdr.ModTime = e.modTime
 373                         if err = tarWr.WriteHeader(&hdr); err != nil {
 374                                 return w.CloseWithError(err)
 375                         }
 376                 }
 377                 hdr.Typeflag = tar.TypeReg
 378                 hdr.Mode = 0666
 379                 for _, e := range files {
 380                         hdr.Name = basePath + e.path[len(rootPath):]
 381                         hdr.ModTime = e.modTime
 382                         hdr.Size = e.size
 383                         if err = tarWr.WriteHeader(&hdr); err != nil {
 384                                 return w.CloseWithError(err)
 385                         }
 386                         fd, err := os.Open(e.path)
 387                         if err != nil {
 388                                 fd.Close()
 389                                 return w.CloseWithError(err)
 390                         }
 391                         if _, err = io.Copy(tarWr, bufio.NewReader(fd)); err != nil {
 392                                 fd.Close()
 393                                 return w.CloseWithError(err)
 394                         }
 395                         fd.Close()
 396                 }
 397                 if err = tarWr.Close(); err != nil {
 398                         return w.CloseWithError(err)
 399                 }
 400                 return w.Close()
 401         }()
 402         return
 403 }
 404
 405 func (ctx *Ctx) TxFile(
 406         node *Node,
 407         nice uint8,
 408         srcPath, dstPath string,
 409         chunkSize, minSize, maxSize int64,
 410         areaId *AreaId,
 411 ) error {
 412         dstPathSpecified := false
 413         if dstPath == "" {
 414                 if srcPath == "-" {
 415                         return errors.New("Must provide destination filename")
 416                 }
 417                 dstPath = filepath.Base(srcPath)
 418         } else {
 419                 dstPathSpecified = true
 420         }
 421         dstPath = filepath.Clean(dstPath)
 422         if filepath.IsAbs(dstPath) {
 423                 return errors.New("Relative destination path required")
 424         }
 425         reader, closer, srcSize, archived, err := prepareTxFile(srcPath)
 426         if closer != nil {
 427                 defer closer.Close()
 428         }
 429         if err != nil {
 430                 return err
 431         }
 432         if archived && !dstPathSpecified {
 433                 dstPath += TarExt
 434         }
 435
 436         if chunkSize == 0 || (srcSize > 0 && srcSize <= chunkSize) {
 437                 pkt, err := NewPkt(PktTypeFile, nice, []byte(dstPath))
 438                 if err != nil {
 439                         return err
 440                 }
 441                 _, finalSize, err := ctx.Tx(
 442                         node, pkt, nice,
 443                         srcSize, minSize, maxSize,
 444                         bufio.NewReader(reader), dstPath, areaId,
 445                 )
 446                 les := LEs{
 447                         {"Type", "file"},
 448                         {"Node", node.Id},
 449                         {"Nice", int(nice)},
 450                         {"Src", srcPath},
 451                         {"Dst", dstPath},
 452                         {"Size", finalSize},
 453                 }
 454                 logMsg := func(les LEs) string {
 455                         return fmt.Sprintf(
 456                                 "File %s (%s) sent to %s:%s",
 457                                 srcPath,
 458                                 humanize.IBytes(uint64(finalSize)),
 459                                 ctx.NodeName(node.Id),
 460                                 dstPath,
 461                         )
 462                 }
 463                 if err == nil {
 464                         ctx.LogI("tx", les, logMsg)
 465                 } else {
 466                         ctx.LogE("tx", les, err, logMsg)
 467                 }
 468                 return err
 469         }
 470
 471         br := bufio.NewReader(reader)
 472         var sizeFull int64
 473         var chunkNum int
 474         checksums := [][MTHSize]byte{}
 475         for {
 476                 lr := io.LimitReader(br, chunkSize)
 477                 path := dstPath + ChunkedSuffixPart + strconv.Itoa(chunkNum)
 478                 pkt, err := NewPkt(PktTypeFile, nice, []byte(path))
 479                 if err != nil {
 480                         return err
 481                 }
 482                 hsh := MTHNew(0, 0)
 483                 _, size, err := ctx.Tx(
 484                         node, pkt, nice,
 485                         0, minSize, maxSize,
 486                         io.TeeReader(lr, hsh),
 487                         path, areaId,
 488                 )
 489
 490                 les := LEs{
 491                         {"Type", "file"},
 492                         {"Node", node.Id},
 493                         {"Nice", int(nice)},
 494                         {"Src", srcPath},
 495                         {"Dst", path},
 496                         {"Size", size},
 497                 }
 498                 logMsg := func(les LEs) string {
 499                         return fmt.Sprintf(
 500                                 "File %s (%s) sent to %s:%s",
 501                                 srcPath,
 502                                 humanize.IBytes(uint64(size)),
 503                                 ctx.NodeName(node.Id),
 504                                 path,
 505                         )
 506                 }
 507                 if err == nil {
 508                         ctx.LogI("tx", les, logMsg)
 509                 } else {
 510                         ctx.LogE("tx", les, err, logMsg)
 511                         return err
 512                 }
 513
 514                 sizeFull += size - PktOverhead
 515                 var checksum [MTHSize]byte
 516                 hsh.Sum(checksum[:0])
 517                 checksums = append(checksums, checksum)
 518                 chunkNum++
 519                 if size < chunkSize {
 520                         break
 521                 }
 522                 if _, err = br.Peek(1); err != nil {
 523                         break
 524                 }
 525         }
 526
 527         metaPkt := ChunkedMeta{
 528                 Magic:     MagicNNCPMv2.B,
 529                 FileSize:  uint64(sizeFull),
 530                 ChunkSize: uint64(chunkSize),
 531                 Checksums: checksums,
 532         }
 533         var buf bytes.Buffer
 534         _, err = xdr.Marshal(&buf, metaPkt)
 535         if err != nil {
 536                 return err
 537         }
 538         path := dstPath + ChunkedSuffixMeta
 539         pkt, err := NewPkt(PktTypeFile, nice, []byte(path))
 540         if err != nil {
 541                 return err
 542         }
 543         metaPktSize := int64(buf.Len())
 544         _, _, err = ctx.Tx(
 545                 node,
 546                 pkt,
 547                 nice,
 548                 metaPktSize, minSize, maxSize,
 549                 &buf, path, areaId,
 550         )
 551         les := LEs{
 552                 {"Type", "file"},
 553                 {"Node", node.Id},
 554                 {"Nice", int(nice)},
 555                 {"Src", srcPath},
 556                 {"Dst", path},
 557                 {"Size", metaPktSize},
 558         }
 559         logMsg := func(les LEs) string {
 560                 return fmt.Sprintf(
 561                         "File %s (%s) sent to %s:%s",
 562                         srcPath,
 563                         humanize.IBytes(uint64(metaPktSize)),
 564                         ctx.NodeName(node.Id),
 565                         path,
 566                 )
 567         }
 568         if err == nil {
 569                 ctx.LogI("tx", les, logMsg)
 570         } else {
 571                 ctx.LogE("tx", les, err, logMsg)
 572         }
 573         return err
 574 }
 575
 576 func (ctx *Ctx) TxFreq(
 577         node *Node,
 578         nice, replyNice uint8,
 579         srcPath, dstPath string,
 580         minSize int64,
 581 ) error {
 582         dstPath = filepath.Clean(dstPath)
 583         if filepath.IsAbs(dstPath) {
 584                 return errors.New("Relative destination path required")
 585         }
 586         srcPath = filepath.Clean(srcPath)
 587         if filepath.IsAbs(srcPath) {
 588                 return errors.New("Relative source path required")
 589         }
 590         pkt, err := NewPkt(PktTypeFreq, replyNice, []byte(srcPath))
 591         if err != nil {
 592                 return err
 593         }
 594         src := strings.NewReader(dstPath)
 595         size := int64(src.Len())
 596         _, _, err = ctx.Tx(node, pkt, nice, size, minSize, MaxFileSize, src, srcPath, nil)
 597         les := LEs{
 598                 {"Type", "freq"},
 599                 {"Node", node.Id},
 600                 {"Nice", int(nice)},
 601                 {"ReplyNice", int(replyNice)},
 602                 {"Src", srcPath},
 603                 {"Dst", dstPath},
 604         }
 605         logMsg := func(les LEs) string {
 606                 return fmt.Sprintf(
 607                         "File request from %s:%s to %s sent",
 608                         ctx.NodeName(node.Id), srcPath,
 609                         dstPath,
 610                 )
 611         }
 612         if err == nil {
 613                 ctx.LogI("tx", les, logMsg)
 614         } else {
 615                 ctx.LogE("tx", les, err, logMsg)
 616         }
 617         return err
 618 }
 619
 620 func (ctx *Ctx) TxExec(
 621         node *Node,
 622         nice, replyNice uint8,
 623         handle string,
 624         args []string,
 625         in io.Reader,
 626         minSize int64, maxSize int64,
 627         noCompress bool,
 628         areaId *AreaId,
 629 ) error {
 630         path := make([][]byte, 0, 1+len(args))
 631         path = append(path, []byte(handle))
 632         for _, arg := range args {
 633                 path = append(path, []byte(arg))
 634         }
 635         pktType := PktTypeExec
 636         if noCompress {
 637                 pktType = PktTypeExecFat
 638         }
 639         pkt, err := NewPkt(pktType, replyNice, bytes.Join(path, []byte{0}))
 640         if err != nil {
 641                 return err
 642         }
 643         compressErr := make(chan error, 1)
 644         if !noCompress {
 645                 pr, pw := io.Pipe()
 646                 compressor, err := zstd.NewWriter(pw, zstd.WithEncoderLevel(zstd.SpeedDefault))
 647                 if err != nil {
 648                         return err
 649                 }
 650                 go func(r io.Reader) {
 651                         if _, err := io.Copy(compressor, r); err != nil {
 652                                 compressErr <- err
 653                                 return
 654                         }
 655                         compressErr <- compressor.Close()
 656                         pw.Close()
 657                 }(in)
 658                 in = pr
 659         }
 660         _, size, err := ctx.Tx(node, pkt, nice, 0, minSize, maxSize, in, handle, areaId)
 661         if !noCompress {
 662                 e := <-compressErr
 663                 if err == nil {
 664                         err = e
 665                 }
 666         }
 667         dst := strings.Join(append([]string{handle}, args...), " ")
 668         les := LEs{
 669                 {"Type", "exec"},
 670                 {"Node", node.Id},
 671                 {"Nice", int(nice)},
 672                 {"ReplyNice", int(replyNice)},
 673                 {"Dst", dst},
 674                 {"Size", size},
 675         }
 676         logMsg := func(les LEs) string {
 677                 return fmt.Sprintf(
 678                         "Exec sent to %s@%s (%s)",
 679                         ctx.NodeName(node.Id), dst, humanize.IBytes(uint64(size)),
 680                 )
 681         }
 682         if err == nil {
 683                 ctx.LogI("tx", les, logMsg)
 684         } else {
 685                 ctx.LogE("tx", les, err, logMsg)
 686         }
 687         return err
 688 }
 689
 690 func (ctx *Ctx) TxTrns(node *Node, nice uint8, size int64, src io.Reader) error {
 691         les := LEs{
 692                 {"Type", "trns"},
 693                 {"Node", node.Id},
 694                 {"Nice", int(nice)},
 695                 {"Size", size},
 696         }
 697         logMsg := func(les LEs) string {
 698                 return fmt.Sprintf(
 699                         "Transitional packet to %s (%s) (nice %s)",
 700                         ctx.NodeName(node.Id),
 701                         humanize.IBytes(uint64(size)),
 702                         NicenessFmt(nice),
 703                 )
 704         }
 705         ctx.LogD("tx", les, logMsg)
 706         if !ctx.IsEnoughSpace(size) {
 707                 err := errors.New("is not enough space")
 708                 ctx.LogE("tx", les, err, logMsg)
 709                 return err
 710         }
 711         tmp, err := ctx.NewTmpFileWHash()
 712         if err != nil {
 713                 return err
 714         }
 715         if _, err = CopyProgressed(
 716                 tmp.W, src, "Tx trns",
 717                 LEs{{"Pkt", node.Id.String()}, {"FullSize", size}},
 718                 ctx.ShowPrgrs,
 719         ); err != nil {
 720                 return err
 721         }
 722         nodePath := filepath.Join(ctx.Spool, node.Id.String())
 723         err = tmp.Commit(filepath.Join(nodePath, string(TTx)))
 724         if err == nil {
 725                 ctx.LogI("tx", les, logMsg)
 726         } else {
 727                 ctx.LogI("tx", append(les, LE{"Err", err}), logMsg)
 728         }
 729         os.Symlink(nodePath, filepath.Join(ctx.Spool, node.Name))
 730         return err
 731 }