src/tx.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2021 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         }
 209         for i := 0; i <= wrappers; i++ {
 210                 r := <-results
 211                 if r.err != nil {
 212                         tmp.Fd.Close()
 213                         return nil, 0, err
 214                 }
 215                 if r.pktEncRaw != nil {
 216                         pktEncRaw = r.pktEncRaw
 217                         if payloadSize == 0 {
 218                                 payloadSize = r.size
 219                         }
 220                 }
 221         }
 222         nodePath := filepath.Join(ctx.Spool, lastNode.Id.String())
 223         err = tmp.Commit(filepath.Join(nodePath, string(TTx)))
 224         os.Symlink(nodePath, filepath.Join(ctx.Spool, lastNode.Name))
 225         if err != nil {
 226                 return lastNode, 0, err
 227         }
 228         if ctx.HdrUsage {
 229                 ctx.HdrWrite(pktEncRaw, filepath.Join(nodePath, string(TTx), tmp.Checksum()))
 230         }
 231         if area != nil {
 232                 msgHashRaw := blake2b.Sum256(pktEncMsg)
 233                 msgHash := Base32Codec.EncodeToString(msgHashRaw[:])
 234                 seenDir := filepath.Join(
 235                         ctx.Spool, ctx.SelfId.String(), AreaDir, areaId.String(),
 236                 )
 237                 seenPath := filepath.Join(seenDir, msgHash)
 238                 les := LEs{
 239                         {"Node", node.Id},
 240                         {"Nice", int(nice)},
 241                         {"Size", expectedSize},
 242                         {"Area", areaId},
 243                         {"AreaMsg", msgHash},
 244                 }
 245                 logMsg := func(les LEs) string {
 246                         return fmt.Sprintf(
 247                                 "Tx area packet to %s (source %s) nice: %s, area %s: %s",
 248                                 ctx.NodeName(node.Id),
 249                                 humanize.IBytes(uint64(expectedSize)),
 250                                 NicenessFmt(nice),
 251                                 area.Name,
 252                                 msgHash,
 253                         )
 254                 }
 255                 if err = ensureDir(seenDir); err != nil {
 256                         ctx.LogE("tx-mkdir", les, err, logMsg)
 257                         return lastNode, 0, err
 258                 }
 259                 if fd, err := os.Create(seenPath); err == nil {
 260                         fd.Close()
 261                         if err = DirSync(seenDir); err != nil {
 262                                 ctx.LogE("tx-dirsync", les, err, logMsg)
 263                                 return lastNode, 0, err
 264                         }
 265                 }
 266                 ctx.LogI("tx-area", les, logMsg)
 267         }
 268         return lastNode, payloadSize, err
 269 }
 270
 271 type DummyCloser struct{}
 272
 273 func (dc DummyCloser) Close() error { return nil }
 274
 275 func prepareTxFile(srcPath string) (
 276         reader io.Reader,
 277         closer io.Closer,
 278         srcSize int64,
 279         archived bool,
 280         rerr error,
 281 ) {
 282         if srcPath == "-" {
 283                 reader = os.Stdin
 284                 closer = os.Stdin
 285                 return
 286         }
 287
 288         srcStat, err := os.Stat(srcPath)
 289         if err != nil {
 290                 rerr = err
 291                 return
 292         }
 293         mode := srcStat.Mode()
 294
 295         if mode.IsRegular() {
 296                 // It is regular file, just send it
 297                 src, err := os.Open(srcPath)
 298                 if err != nil {
 299                         rerr = err
 300                         return
 301                 }
 302                 reader = src
 303                 closer = src
 304                 srcSize = srcStat.Size()
 305                 return
 306         }
 307
 308         if !mode.IsDir() {
 309                 rerr = errors.New("unsupported file type")
 310                 return
 311         }
 312
 313         // It is directory, create PAX archive with its contents
 314         archived = true
 315         basePath := filepath.Base(srcPath)
 316         rootPath, err := filepath.Abs(srcPath)
 317         if err != nil {
 318                 rerr = err
 319                 return
 320         }
 321         type einfo struct {
 322                 path    string
 323                 modTime time.Time
 324                 size    int64
 325         }
 326         dirs := make([]einfo, 0, 1<<10)
 327         files := make([]einfo, 0, 1<<10)
 328         rerr = filepath.Walk(rootPath, func(path string, info os.FileInfo, err error) error {
 329                 if err != nil {
 330                         return err
 331                 }
 332                 if info.IsDir() {
 333                         // directory header, PAX record header+contents
 334                         srcSize += TarBlockSize + 2*TarBlockSize
 335                         dirs = append(dirs, einfo{path: path, modTime: info.ModTime()})
 336                 } else {
 337                         // file header, PAX record header+contents, file content
 338                         srcSize += TarBlockSize + 2*TarBlockSize + info.Size()
 339                         if n := info.Size() % TarBlockSize; n != 0 {
 340                                 srcSize += TarBlockSize - n // padding
 341                         }
 342                         files = append(files, einfo{
 343                                 path:    path,
 344                                 modTime: info.ModTime(),
 345                                 size:    info.Size(),
 346                         })
 347                 }
 348                 return nil
 349         })
 350         if rerr != nil {
 351                 return
 352         }
 353
 354         r, w := io.Pipe()
 355         reader = r
 356         closer = DummyCloser{}
 357         srcSize += 2 * TarBlockSize // termination block
 358
 359         go func() error {
 360                 tarWr := tar.NewWriter(w)
 361                 hdr := tar.Header{
 362                         Typeflag: tar.TypeDir,
 363                         Mode:     0777,
 364                         PAXRecords: map[string]string{
 365                                 "comment": "Autogenerated by " + VersionGet(),
 366                         },
 367                         Format: tar.FormatPAX,
 368                 }
 369                 for _, e := range dirs {
 370                         hdr.Name = basePath + e.path[len(rootPath):]
 371                         hdr.ModTime = e.modTime
 372                         if err = tarWr.WriteHeader(&hdr); err != nil {
 373                                 return w.CloseWithError(err)
 374                         }
 375                 }
 376                 hdr.Typeflag = tar.TypeReg
 377                 hdr.Mode = 0666
 378                 for _, e := range files {
 379                         hdr.Name = basePath + e.path[len(rootPath):]
 380                         hdr.ModTime = e.modTime
 381                         hdr.Size = e.size
 382                         if err = tarWr.WriteHeader(&hdr); err != nil {
 383                                 return w.CloseWithError(err)
 384                         }
 385                         fd, err := os.Open(e.path)
 386                         if err != nil {
 387                                 fd.Close()
 388                                 return w.CloseWithError(err)
 389                         }
 390                         if _, err = io.Copy(tarWr, bufio.NewReader(fd)); err != nil {
 391                                 fd.Close()
 392                                 return w.CloseWithError(err)
 393                         }
 394                         fd.Close()
 395                 }
 396                 if err = tarWr.Close(); err != nil {
 397                         return w.CloseWithError(err)
 398                 }
 399                 return w.Close()
 400         }()
 401         return
 402 }
 403
 404 func (ctx *Ctx) TxFile(
 405         node *Node,
 406         nice uint8,
 407         srcPath, dstPath string,
 408         chunkSize, minSize, maxSize int64,
 409         areaId *AreaId,
 410 ) error {
 411         dstPathSpecified := false
 412         if dstPath == "" {
 413                 if srcPath == "-" {
 414                         return errors.New("Must provide destination filename")
 415                 }
 416                 dstPath = filepath.Base(srcPath)
 417         } else {
 418                 dstPathSpecified = true
 419         }
 420         dstPath = filepath.Clean(dstPath)
 421         if filepath.IsAbs(dstPath) {
 422                 return errors.New("Relative destination path required")
 423         }
 424         reader, closer, srcSize, archived, err := prepareTxFile(srcPath)
 425         if closer != nil {
 426                 defer closer.Close()
 427         }
 428         if err != nil {
 429                 return err
 430         }
 431         if archived && !dstPathSpecified {
 432                 dstPath += TarExt
 433         }
 434
 435         if chunkSize == 0 || (srcSize > 0 && srcSize <= chunkSize) {
 436                 pkt, err := NewPkt(PktTypeFile, nice, []byte(dstPath))
 437                 if err != nil {
 438                         return err
 439                 }
 440                 _, finalSize, err := ctx.Tx(
 441                         node, pkt, nice,
 442                         srcSize, minSize, maxSize,
 443                         bufio.NewReader(reader), dstPath, areaId,
 444                 )
 445                 les := LEs{
 446                         {"Type", "file"},
 447                         {"Node", node.Id},
 448                         {"Nice", int(nice)},
 449                         {"Src", srcPath},
 450                         {"Dst", dstPath},
 451                         {"Size", finalSize},
 452                 }
 453                 logMsg := func(les LEs) string {
 454                         return fmt.Sprintf(
 455                                 "File %s (%s) sent to %s:%s",
 456                                 srcPath,
 457                                 humanize.IBytes(uint64(finalSize)),
 458                                 ctx.NodeName(node.Id),
 459                                 dstPath,
 460                         )
 461                 }
 462                 if err == nil {
 463                         ctx.LogI("tx", les, logMsg)
 464                 } else {
 465                         ctx.LogE("tx", les, err, logMsg)
 466                 }
 467                 return err
 468         }
 469
 470         br := bufio.NewReader(reader)
 471         var sizeFull int64
 472         var chunkNum int
 473         checksums := [][MTHSize]byte{}
 474         for {
 475                 lr := io.LimitReader(br, chunkSize)
 476                 path := dstPath + ChunkedSuffixPart + strconv.Itoa(chunkNum)
 477                 pkt, err := NewPkt(PktTypeFile, nice, []byte(path))
 478                 if err != nil {
 479                         return err
 480                 }
 481                 hsh := MTHNew(0, 0)
 482                 _, size, err := ctx.Tx(
 483                         node, pkt, nice,
 484                         0, minSize, maxSize,
 485                         io.TeeReader(lr, hsh),
 486                         path, areaId,
 487                 )
 488
 489                 les := LEs{
 490                         {"Type", "file"},
 491                         {"Node", node.Id},
 492                         {"Nice", int(nice)},
 493                         {"Src", srcPath},
 494                         {"Dst", path},
 495                         {"Size", size},
 496                 }
 497                 logMsg := func(les LEs) string {
 498                         return fmt.Sprintf(
 499                                 "File %s (%s) sent to %s:%s",
 500                                 srcPath,
 501                                 humanize.IBytes(uint64(size)),
 502                                 ctx.NodeName(node.Id),
 503                                 path,
 504                         )
 505                 }
 506                 if err == nil {
 507                         ctx.LogI("tx", les, logMsg)
 508                 } else {
 509                         ctx.LogE("tx", les, err, logMsg)
 510                         return err
 511                 }
 512
 513                 sizeFull += size - PktOverhead
 514                 var checksum [MTHSize]byte
 515                 hsh.Sum(checksum[:0])
 516                 checksums = append(checksums, checksum)
 517                 chunkNum++
 518                 if size < chunkSize {
 519                         break
 520                 }
 521                 if _, err = br.Peek(1); err != nil {
 522                         break
 523                 }
 524         }
 525
 526         metaPkt := ChunkedMeta{
 527                 Magic:     MagicNNCPMv2.B,
 528                 FileSize:  uint64(sizeFull),
 529                 ChunkSize: uint64(chunkSize),
 530                 Checksums: checksums,
 531         }
 532         var buf bytes.Buffer
 533         _, err = xdr.Marshal(&buf, metaPkt)
 534         if err != nil {
 535                 return err
 536         }
 537         path := dstPath + ChunkedSuffixMeta
 538         pkt, err := NewPkt(PktTypeFile, nice, []byte(path))
 539         if err != nil {
 540                 return err
 541         }
 542         metaPktSize := int64(buf.Len())
 543         _, _, err = ctx.Tx(
 544                 node,
 545                 pkt,
 546                 nice,
 547                 metaPktSize, minSize, maxSize,
 548                 &buf, path, areaId,
 549         )
 550         les := LEs{
 551                 {"Type", "file"},
 552                 {"Node", node.Id},
 553                 {"Nice", int(nice)},
 554                 {"Src", srcPath},
 555                 {"Dst", path},
 556                 {"Size", metaPktSize},
 557         }
 558         logMsg := func(les LEs) string {
 559                 return fmt.Sprintf(
 560                         "File %s (%s) sent to %s:%s",
 561                         srcPath,
 562                         humanize.IBytes(uint64(metaPktSize)),
 563                         ctx.NodeName(node.Id),
 564                         path,
 565                 )
 566         }
 567         if err == nil {
 568                 ctx.LogI("tx", les, logMsg)
 569         } else {
 570                 ctx.LogE("tx", les, err, logMsg)
 571         }
 572         return err
 573 }
 574
 575 func (ctx *Ctx) TxFreq(
 576         node *Node,
 577         nice, replyNice uint8,
 578         srcPath, dstPath string,
 579         minSize int64,
 580 ) error {
 581         dstPath = filepath.Clean(dstPath)
 582         if filepath.IsAbs(dstPath) {
 583                 return errors.New("Relative destination path required")
 584         }
 585         srcPath = filepath.Clean(srcPath)
 586         if filepath.IsAbs(srcPath) {
 587                 return errors.New("Relative source path required")
 588         }
 589         pkt, err := NewPkt(PktTypeFreq, replyNice, []byte(srcPath))
 590         if err != nil {
 591                 return err
 592         }
 593         src := strings.NewReader(dstPath)
 594         size := int64(src.Len())
 595         _, _, err = ctx.Tx(node, pkt, nice, size, minSize, MaxFileSize, src, srcPath, nil)
 596         les := LEs{
 597                 {"Type", "freq"},
 598                 {"Node", node.Id},
 599                 {"Nice", int(nice)},
 600                 {"ReplyNice", int(replyNice)},
 601                 {"Src", srcPath},
 602                 {"Dst", dstPath},
 603         }
 604         logMsg := func(les LEs) string {
 605                 return fmt.Sprintf(
 606                         "File request from %s:%s to %s sent",
 607                         ctx.NodeName(node.Id), srcPath,
 608                         dstPath,
 609                 )
 610         }
 611         if err == nil {
 612                 ctx.LogI("tx", les, logMsg)
 613         } else {
 614                 ctx.LogE("tx", les, err, logMsg)
 615         }
 616         return err
 617 }
 618
 619 func (ctx *Ctx) TxExec(
 620         node *Node,
 621         nice, replyNice uint8,
 622         handle string,
 623         args []string,
 624         in io.Reader,
 625         minSize int64, maxSize int64,
 626         noCompress bool,
 627         areaId *AreaId,
 628 ) error {
 629         path := make([][]byte, 0, 1+len(args))
 630         path = append(path, []byte(handle))
 631         for _, arg := range args {
 632                 path = append(path, []byte(arg))
 633         }
 634         pktType := PktTypeExec
 635         if noCompress {
 636                 pktType = PktTypeExecFat
 637         }
 638         pkt, err := NewPkt(pktType, replyNice, bytes.Join(path, []byte{0}))
 639         if err != nil {
 640                 return err
 641         }
 642         compressErr := make(chan error, 1)
 643         if !noCompress {
 644                 pr, pw := io.Pipe()
 645                 compressor, err := zstd.NewWriter(pw, zstd.WithEncoderLevel(zstd.SpeedDefault))
 646                 if err != nil {
 647                         return err
 648                 }
 649                 go func(r io.Reader) {
 650                         if _, err := io.Copy(compressor, r); err != nil {
 651                                 compressErr <- err
 652                                 return
 653                         }
 654                         compressErr <- compressor.Close()
 655                         pw.Close()
 656                 }(in)
 657                 in = pr
 658         }
 659         _, size, err := ctx.Tx(node, pkt, nice, 0, minSize, maxSize, in, handle, areaId)
 660         if !noCompress {
 661                 e := <-compressErr
 662                 if err == nil {
 663                         err = e
 664                 }
 665         }
 666         dst := strings.Join(append([]string{handle}, args...), " ")
 667         les := LEs{
 668                 {"Type", "exec"},
 669                 {"Node", node.Id},
 670                 {"Nice", int(nice)},
 671                 {"ReplyNice", int(replyNice)},
 672                 {"Dst", dst},
 673                 {"Size", size},
 674         }
 675         logMsg := func(les LEs) string {
 676                 return fmt.Sprintf(
 677                         "Exec sent to %s@%s (%s)",
 678                         ctx.NodeName(node.Id), dst, humanize.IBytes(uint64(size)),
 679                 )
 680         }
 681         if err == nil {
 682                 ctx.LogI("tx", les, logMsg)
 683         } else {
 684                 ctx.LogE("tx", les, err, logMsg)
 685         }
 686         return err
 687 }
 688
 689 func (ctx *Ctx) TxTrns(node *Node, nice uint8, size int64, src io.Reader) error {
 690         les := LEs{
 691                 {"Type", "trns"},
 692                 {"Node", node.Id},
 693                 {"Nice", int(nice)},
 694                 {"Size", size},
 695         }
 696         logMsg := func(les LEs) string {
 697                 return fmt.Sprintf(
 698                         "Transitional packet to %s (%s) (nice %s)",
 699                         ctx.NodeName(node.Id),
 700                         humanize.IBytes(uint64(size)),
 701                         NicenessFmt(nice),
 702                 )
 703         }
 704         ctx.LogD("tx", les, logMsg)
 705         if !ctx.IsEnoughSpace(size) {
 706                 err := errors.New("is not enough space")
 707                 ctx.LogE("tx", les, err, logMsg)
 708                 return err
 709         }
 710         tmp, err := ctx.NewTmpFileWHash()
 711         if err != nil {
 712                 return err
 713         }
 714         if _, err = CopyProgressed(
 715                 tmp.W, src, "Tx trns",
 716                 LEs{{"Pkt", node.Id.String()}, {"FullSize", size}},
 717                 ctx.ShowPrgrs,
 718         ); err != nil {
 719                 return err
 720         }
 721         nodePath := filepath.Join(ctx.Spool, node.Id.String())
 722         err = tmp.Commit(filepath.Join(nodePath, string(TTx)))
 723         if err == nil {
 724                 ctx.LogI("tx", les, logMsg)
 725         } else {
 726                 ctx.LogI("tx", append(les, LE{"Err", err}), logMsg)
 727         }
 728         os.Symlink(nodePath, filepath.Join(ctx.Spool, node.Name))
 729         return err
 730 }