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

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "fmt"
   8         "gopkg.in/yaml.v3"
   9         "io/ioutil"
  10         "math/big"
  11         "os"
  12         "path"
  13         "path/filepath"
  14         "sort"
  15         "strings"
  16         "time"
  17 )
  18
  19 type TransactionType struct {
  20         Handler        func(*ClientConn, *Transaction) ([]Transaction, error) // function for handling the transaction type
  21         Name           string                                                 // Name of transaction as it will appear in logging
  22         RequiredFields []requiredField
  23 }
  24
  25 var TransactionHandlers = map[uint16]TransactionType{
  26         // Server initiated
  27         tranChatMsg: {
  28                 Name: "tranChatMsg",
  29         },
  30         // Server initiated
  31         tranNotifyChangeUser: {
  32                 Name: "tranNotifyChangeUser",
  33         },
  34         tranError: {
  35                 Name: "tranError",
  36         },
  37         tranShowAgreement: {
  38                 Name: "tranShowAgreement",
  39         },
  40         tranUserAccess: {
  41                 Name: "tranUserAccess",
  42         },
  43         tranNotifyDeleteUser: {
  44                 Name: "tranNotifyDeleteUser",
  45         },
  46         tranAgreed: {
  47                 Name:    "tranAgreed",
  48                 Handler: HandleTranAgreed,
  49         },
  50         tranChatSend: {
  51                 Name:    "tranChatSend",
  52                 Handler: HandleChatSend,
  53                 RequiredFields: []requiredField{
  54                         {
  55                                 ID:     fieldData,
  56                                 minLen: 0,
  57                         },
  58                 },
  59         },
  60         tranDelNewsArt: {
  61                 Name:    "tranDelNewsArt",
  62                 Handler: HandleDelNewsArt,
  63         },
  64         tranDelNewsItem: {
  65                 Name:    "tranDelNewsItem",
  66                 Handler: HandleDelNewsItem,
  67         },
  68         tranDeleteFile: {
  69                 Name:    "tranDeleteFile",
  70                 Handler: HandleDeleteFile,
  71         },
  72         tranDeleteUser: {
  73                 Name:    "tranDeleteUser",
  74                 Handler: HandleDeleteUser,
  75         },
  76         tranDisconnectUser: {
  77                 Name:    "tranDisconnectUser",
  78                 Handler: HandleDisconnectUser,
  79         },
  80         tranDownloadFile: {
  81                 Name:    "tranDownloadFile",
  82                 Handler: HandleDownloadFile,
  83         },
  84         tranDownloadFldr: {
  85                 Name:    "tranDownloadFldr",
  86                 Handler: HandleDownloadFolder,
  87         },
  88         tranGetClientInfoText: {
  89                 Name:    "tranGetClientInfoText",
  90                 Handler: HandleGetClientInfoText,
  91         },
  92         tranGetFileInfo: {
  93                 Name:    "tranGetFileInfo",
  94                 Handler: HandleGetFileInfo,
  95         },
  96         tranGetFileNameList: {
  97                 Name:    "tranGetFileNameList",
  98                 Handler: HandleGetFileNameList,
  99         },
 100         tranGetMsgs: {
 101                 Name:    "tranGetMsgs",
 102                 Handler: HandleGetMsgs,
 103         },
 104         tranGetNewsArtData: {
 105                 Name:    "tranGetNewsArtData",
 106                 Handler: HandleGetNewsArtData,
 107         },
 108         tranGetNewsArtNameList: {
 109                 Name:    "tranGetNewsArtNameList",
 110                 Handler: HandleGetNewsArtNameList,
 111         },
 112         tranGetNewsCatNameList: {
 113                 Name:    "tranGetNewsCatNameList",
 114                 Handler: HandleGetNewsCatNameList,
 115         },
 116         tranGetUser: {
 117                 Name:    "tranGetUser",
 118                 Handler: HandleGetUser,
 119         },
 120         tranGetUserNameList: {
 121                 Name:    "tranHandleGetUserNameList",
 122                 Handler: HandleGetUserNameList,
 123         },
 124         tranInviteNewChat: {
 125                 Name:    "tranInviteNewChat",
 126                 Handler: HandleInviteNewChat,
 127         },
 128         tranInviteToChat: {
 129                 Name:    "tranInviteToChat",
 130                 Handler: HandleInviteToChat,
 131         },
 132         tranJoinChat: {
 133                 Name:    "tranJoinChat",
 134                 Handler: HandleJoinChat,
 135         },
 136         tranKeepAlive: {
 137                 Name:    "tranKeepAlive",
 138                 Handler: HandleKeepAlive,
 139         },
 140         tranLeaveChat: {
 141                 Name:    "tranJoinChat",
 142                 Handler: HandleLeaveChat,
 143         },
 144         tranListUsers: {
 145                 Name:    "tranListUsers",
 146                 Handler: HandleListUsers,
 147         },
 148         tranMoveFile: {
 149                 Name:    "tranMoveFile",
 150                 Handler: HandleMoveFile,
 151         },
 152         tranNewFolder: {
 153                 Name:    "tranNewFolder",
 154                 Handler: HandleNewFolder,
 155         },
 156         tranNewNewsCat: {
 157                 Name:    "tranNewNewsCat",
 158                 Handler: HandleNewNewsCat,
 159         },
 160         tranNewNewsFldr: {
 161                 Name:    "tranNewNewsFldr",
 162                 Handler: HandleNewNewsFldr,
 163         },
 164         tranNewUser: {
 165                 Name:    "tranNewUser",
 166                 Handler: HandleNewUser,
 167         },
 168         tranUpdateUser: {
 169                 Name:    "tranUpdateUser",
 170                 Handler: HandleUpdateUser,
 171         },
 172         tranOldPostNews: {
 173                 Name:    "tranOldPostNews",
 174                 Handler: HandleTranOldPostNews,
 175         },
 176         tranPostNewsArt: {
 177                 Name:    "tranPostNewsArt",
 178                 Handler: HandlePostNewsArt,
 179         },
 180         tranRejectChatInvite: {
 181                 Name:    "tranRejectChatInvite",
 182                 Handler: HandleRejectChatInvite,
 183         },
 184         tranSendInstantMsg: {
 185                 Name:    "tranSendInstantMsg",
 186                 Handler: HandleSendInstantMsg,
 187                 RequiredFields: []requiredField{
 188                         {
 189                                 ID:     fieldData,
 190                                 minLen: 0,
 191                         },
 192                         {
 193                                 ID: fieldUserID,
 194                         },
 195                 },
 196         },
 197         tranSetChatSubject: {
 198                 Name:    "tranSetChatSubject",
 199                 Handler: HandleSetChatSubject,
 200         },
 201         tranMakeFileAlias: {
 202                 Name:    "tranMakeFileAlias",
 203                 Handler: HandleMakeAlias,
 204                 RequiredFields: []requiredField{
 205                         {ID: fieldFileName, minLen: 1},
 206                         {ID: fieldFilePath, minLen: 1},
 207                         {ID: fieldFileNewPath, minLen: 1},
 208                 },
 209         },
 210         tranSetClientUserInfo: {
 211                 Name:    "tranSetClientUserInfo",
 212                 Handler: HandleSetClientUserInfo,
 213         },
 214         tranSetFileInfo: {
 215                 Name:    "tranSetFileInfo",
 216                 Handler: HandleSetFileInfo,
 217         },
 218         tranSetUser: {
 219                 Name:    "tranSetUser",
 220                 Handler: HandleSetUser,
 221         },
 222         tranUploadFile: {
 223                 Name:    "tranUploadFile",
 224                 Handler: HandleUploadFile,
 225         },
 226         tranUploadFldr: {
 227                 Name:    "tranUploadFldr",
 228                 Handler: HandleUploadFolder,
 229         },
 230         tranUserBroadcast: {
 231                 Name:    "tranUserBroadcast",
 232                 Handler: HandleUserBroadcast,
 233         },
 234         tranDownloadBanner: {
 235                 Name:    "tranDownloadBanner",
 236                 Handler: HandleDownloadBanner,
 237         },
 238 }
 239
 240 func HandleChatSend(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 241         if !authorize(cc.Account.Access, accessSendChat) {
 242                 res = append(res, cc.NewErrReply(t, "You are not allowed to participate in chat."))
 243                 return res, err
 244         }
 245
 246         // Truncate long usernames
 247         trunc := fmt.Sprintf("%13s", cc.UserName)
 248         formattedMsg := fmt.Sprintf("\r%.14s:  %s", trunc, t.GetField(fieldData).Data)
 249
 250         // By holding the option key, Hotline chat allows users to send /me formatted messages like:
 251         // *** Halcyon does stuff
 252         // This is indicated by the presence of the optional field fieldChatOptions in the transaction payload
 253         if t.GetField(fieldChatOptions).Data != nil {
 254                 formattedMsg = fmt.Sprintf("\r*** %s %s", cc.UserName, t.GetField(fieldData).Data)
 255         }
 256
 257         chatID := t.GetField(fieldChatID).Data
 258         // a non-nil chatID indicates the message belongs to a private chat
 259         if chatID != nil {
 260                 chatInt := binary.BigEndian.Uint32(chatID)
 261                 privChat := cc.Server.PrivateChats[chatInt]
 262
 263                 clients := sortedClients(privChat.ClientConn)
 264
 265                 // send the message to all connected clients of the private chat
 266                 for _, c := range clients {
 267                         res = append(res, *NewTransaction(
 268                                 tranChatMsg,
 269                                 c.ID,
 270                                 NewField(fieldChatID, chatID),
 271                                 NewField(fieldData, []byte(formattedMsg)),
 272                         ))
 273                 }
 274                 return res, err
 275         }
 276
 277         for _, c := range sortedClients(cc.Server.Clients) {
 278                 // Filter out clients that do not have the read chat permission
 279                 if authorize(c.Account.Access, accessReadChat) {
 280                         res = append(res, *NewTransaction(tranChatMsg, c.ID, NewField(fieldData, []byte(formattedMsg))))
 281                 }
 282         }
 283
 284         return res, err
 285 }
 286
 287 // HandleSendInstantMsg sends instant message to the user on the current server.
 288 // Fields used in the request:
 289 //      103     User ID
 290 //      113     Options
 291 //              One of the following values:
 292 //              - User message (myOpt_UserMessage = 1)
 293 //              - Refuse message (myOpt_RefuseMessage = 2)
 294 //              - Refuse chat (myOpt_RefuseChat  = 3)
 295 //              - Automatic response (myOpt_AutomaticResponse = 4)"
 296 //      101     Data    Optional
 297 //      214     Quoting message Optional
 298 //
 299 // Fields used in the reply:
 300 // None
 301 func HandleSendInstantMsg(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 302         msg := t.GetField(fieldData)
 303         ID := t.GetField(fieldUserID)
 304
 305         reply := NewTransaction(
 306                 tranServerMsg,
 307                 &ID.Data,
 308                 NewField(fieldData, msg.Data),
 309                 NewField(fieldUserName, cc.UserName),
 310                 NewField(fieldUserID, *cc.ID),
 311                 NewField(fieldOptions, []byte{0, 1}),
 312         )
 313
 314         // Later versions of Hotline include the original message in the fieldQuotingMsg field so
 315         //  the receiving client can display both the received message and what it is in reply to
 316         if t.GetField(fieldQuotingMsg).Data != nil {
 317                 reply.Fields = append(reply.Fields, NewField(fieldQuotingMsg, t.GetField(fieldQuotingMsg).Data))
 318         }
 319
 320         res = append(res, *reply)
 321
 322         id, _ := byteToInt(ID.Data)
 323         otherClient, ok := cc.Server.Clients[uint16(id)]
 324         if !ok {
 325                 return res, errors.New("invalid client ID")
 326         }
 327
 328         // Respond with auto reply if other client has it enabled
 329         if len(otherClient.AutoReply) > 0 {
 330                 res = append(res,
 331                         *NewTransaction(
 332                                 tranServerMsg,
 333                                 cc.ID,
 334                                 NewField(fieldData, otherClient.AutoReply),
 335                                 NewField(fieldUserName, otherClient.UserName),
 336                                 NewField(fieldUserID, *otherClient.ID),
 337                                 NewField(fieldOptions, []byte{0, 1}),
 338                         ),
 339                 )
 340         }
 341
 342         res = append(res, cc.NewReply(t))
 343
 344         return res, err
 345 }
 346
 347 func HandleGetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 348         fileName := t.GetField(fieldFileName).Data
 349         filePath := t.GetField(fieldFilePath).Data
 350
 351         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 352         if err != nil {
 353                 return res, err
 354         }
 355
 356         fw, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 357         if err != nil {
 358                 return res, err
 359         }
 360
 361         res = append(res, cc.NewReply(t,
 362                 NewField(fieldFileName, []byte(fw.name)),
 363                 NewField(fieldFileTypeString, fw.ffo.FlatFileInformationFork.friendlyType()),
 364                 NewField(fieldFileCreatorString, fw.ffo.FlatFileInformationFork.friendlyCreator()),
 365                 NewField(fieldFileComment, fw.ffo.FlatFileInformationFork.Comment),
 366                 NewField(fieldFileType, fw.ffo.FlatFileInformationFork.TypeSignature),
 367                 NewField(fieldFileCreateDate, fw.ffo.FlatFileInformationFork.CreateDate),
 368                 NewField(fieldFileModifyDate, fw.ffo.FlatFileInformationFork.ModifyDate),
 369                 NewField(fieldFileSize, fw.totalSize()),
 370         ))
 371         return res, err
 372 }
 373
 374 // HandleSetFileInfo updates a file or folder name and/or comment from the Get Info window
 375 // Fields used in the request:
 376 // * 201        File name
 377 // * 202        File path       Optional
 378 // * 211        File new name   Optional
 379 // * 210        File comment    Optional
 380 // Fields used in the reply:    None
 381 func HandleSetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 382         fileName := t.GetField(fieldFileName).Data
 383         filePath := t.GetField(fieldFilePath).Data
 384
 385         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 386         if err != nil {
 387                 return res, err
 388         }
 389
 390         fi, err := cc.Server.FS.Stat(fullFilePath)
 391         if err != nil {
 392                 return res, err
 393         }
 394
 395         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 396         if err != nil {
 397                 return res, err
 398         }
 399         if t.GetField(fieldFileComment).Data != nil {
 400                 switch mode := fi.Mode(); {
 401                 case mode.IsDir():
 402                         if !authorize(cc.Account.Access, accessSetFolderComment) {
 403                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for folders."))
 404                                 return res, err
 405                         }
 406                 case mode.IsRegular():
 407                         if !authorize(cc.Account.Access, accessSetFileComment) {
 408                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for files."))
 409                                 return res, err
 410                         }
 411                 }
 412
 413                 if err := hlFile.ffo.FlatFileInformationFork.setComment(t.GetField(fieldFileComment).Data); err != nil {
 414                         return res, err
 415                 }
 416                 w, err := hlFile.infoForkWriter()
 417                 if err != nil {
 418                         return res, err
 419                 }
 420                 _, err = w.Write(hlFile.ffo.FlatFileInformationFork.MarshalBinary())
 421                 if err != nil {
 422                         return res, err
 423                 }
 424         }
 425
 426         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, t.GetField(fieldFileNewName).Data)
 427         if err != nil {
 428                 return nil, err
 429         }
 430
 431         fileNewName := t.GetField(fieldFileNewName).Data
 432
 433         if fileNewName != nil {
 434                 switch mode := fi.Mode(); {
 435                 case mode.IsDir():
 436                         if !authorize(cc.Account.Access, accessRenameFolder) {
 437                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename folders."))
 438                                 return res, err
 439                         }
 440                         err = os.Rename(fullFilePath, fullNewFilePath)
 441                         if os.IsNotExist(err) {
 442                                 res = append(res, cc.NewErrReply(t, "Cannot rename folder "+string(fileName)+" because it does not exist or cannot be found."))
 443                                 return res, err
 444                         }
 445                 case mode.IsRegular():
 446                         if !authorize(cc.Account.Access, accessRenameFile) {
 447                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename files."))
 448                                 return res, err
 449                         }
 450                         fileDir, err := readPath(cc.Server.Config.FileRoot, filePath, []byte{})
 451                         if err != nil {
 452                                 return nil, err
 453                         }
 454                         hlFile.name = string(fileNewName)
 455                         err = hlFile.move(fileDir)
 456                         if os.IsNotExist(err) {
 457                                 res = append(res, cc.NewErrReply(t, "Cannot rename file "+string(fileName)+" because it does not exist or cannot be found."))
 458                                 return res, err
 459                         }
 460                         if err != nil {
 461                                 panic(err)
 462                         }
 463                 }
 464         }
 465
 466         res = append(res, cc.NewReply(t))
 467         return res, err
 468 }
 469
 470 // HandleDeleteFile deletes a file or folder
 471 // Fields used in the request:
 472 // * 201        File name
 473 // * 202        File path
 474 // Fields used in the reply: none
 475 func HandleDeleteFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 476         fileName := t.GetField(fieldFileName).Data
 477         filePath := t.GetField(fieldFilePath).Data
 478
 479         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 480         if err != nil {
 481                 return res, err
 482         }
 483
 484         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 485         if err != nil {
 486                 return res, err
 487         }
 488
 489         fi, err := hlFile.dataFile()
 490         if err != nil {
 491                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+string(fileName)+" because it does not exist or cannot be found."))
 492                 return res, nil
 493         }
 494
 495         switch mode := fi.Mode(); {
 496         case mode.IsDir():
 497                 if !authorize(cc.Account.Access, accessDeleteFolder) {
 498                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete folders."))
 499                         return res, err
 500                 }
 501         case mode.IsRegular():
 502                 if !authorize(cc.Account.Access, accessDeleteFile) {
 503                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete files."))
 504                         return res, err
 505                 }
 506         }
 507
 508         if err := hlFile.delete(); err != nil {
 509                 return res, err
 510         }
 511
 512         res = append(res, cc.NewReply(t))
 513         return res, err
 514 }
 515
 516 // HandleMoveFile moves files or folders. Note: seemingly not documented
 517 func HandleMoveFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 518         fileName := string(t.GetField(fieldFileName).Data)
 519
 520         filePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
 521         if err != nil {
 522                 return res, err
 523         }
 524
 525         fileNewPath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFileNewPath).Data, nil)
 526         if err != nil {
 527                 return res, err
 528         }
 529
 530         cc.logger.Infow("Move file", "src", filePath+"/"+fileName, "dst", fileNewPath+"/"+fileName)
 531
 532         hlFile, err := newFileWrapper(cc.Server.FS, filePath, 0)
 533         if err != nil {
 534                 return res, err
 535         }
 536
 537         fi, err := hlFile.dataFile()
 538         if err != nil {
 539                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+fileName+" because it does not exist or cannot be found."))
 540                 return res, err
 541         }
 542         if err != nil {
 543                 return res, err
 544         }
 545         switch mode := fi.Mode(); {
 546         case mode.IsDir():
 547                 if !authorize(cc.Account.Access, accessMoveFolder) {
 548                         res = append(res, cc.NewErrReply(t, "You are not allowed to move folders."))
 549                         return res, err
 550                 }
 551         case mode.IsRegular():
 552                 if !authorize(cc.Account.Access, accessMoveFile) {
 553                         res = append(res, cc.NewErrReply(t, "You are not allowed to move files."))
 554                         return res, err
 555                 }
 556         }
 557         if err := hlFile.move(fileNewPath); err != nil {
 558                 return res, err
 559         }
 560         // TODO: handle other possible errors; e.g. fileWrapper delete fails due to fileWrapper permission issue
 561
 562         res = append(res, cc.NewReply(t))
 563         return res, err
 564 }
 565
 566 func HandleNewFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 567         if !authorize(cc.Account.Access, accessCreateFolder) {
 568                 res = append(res, cc.NewErrReply(t, "You are not allowed to create folders."))
 569                 return res, err
 570         }
 571         folderName := string(t.GetField(fieldFileName).Data)
 572
 573         folderName = path.Join("/", folderName)
 574
 575         var subPath string
 576
 577         // fieldFilePath is only present for nested paths
 578         if t.GetField(fieldFilePath).Data != nil {
 579                 var newFp FilePath
 580                 err := newFp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
 581                 if err != nil {
 582                         return nil, err
 583                 }
 584
 585                 for _, pathItem := range newFp.Items {
 586                         subPath = filepath.Join("/", subPath, string(pathItem.Name))
 587                 }
 588         }
 589         newFolderPath := path.Join(cc.Server.Config.FileRoot, subPath, folderName)
 590
 591         // TODO: check path and folder name lengths
 592
 593         if _, err := cc.Server.FS.Stat(newFolderPath); !os.IsNotExist(err) {
 594                 msg := fmt.Sprintf("Cannot create folder \"%s\" because there is already a file or folder with that name.", folderName)
 595                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 596         }
 597
 598         // TODO: check for disallowed characters to maintain compatibility for original client
 599
 600         if err := cc.Server.FS.Mkdir(newFolderPath, 0777); err != nil {
 601                 msg := fmt.Sprintf("Cannot create folder \"%s\" because an error occurred.", folderName)
 602                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 603         }
 604
 605         res = append(res, cc.NewReply(t))
 606         return res, err
 607 }
 608
 609 func HandleSetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 610         if !authorize(cc.Account.Access, accessModifyUser) {
 611                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 612                 return res, err
 613         }
 614
 615         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 616         userName := string(t.GetField(fieldUserName).Data)
 617
 618         newAccessLvl := t.GetField(fieldUserAccess).Data
 619
 620         account := cc.Server.Accounts[login]
 621         account.Access = &newAccessLvl
 622         account.Name = userName
 623
 624         // If the password field is cleared in the Hotline edit user UI, the SetUser transaction does
 625         // not include fieldUserPassword
 626         if t.GetField(fieldUserPassword).Data == nil {
 627                 account.Password = hashAndSalt([]byte(""))
 628         }
 629         if len(t.GetField(fieldUserPassword).Data) > 1 {
 630                 account.Password = hashAndSalt(t.GetField(fieldUserPassword).Data)
 631         }
 632
 633         out, err := yaml.Marshal(&account)
 634         if err != nil {
 635                 return res, err
 636         }
 637         if err := os.WriteFile(cc.Server.ConfigDir+"Users/"+login+".yaml", out, 0666); err != nil {
 638                 return res, err
 639         }
 640
 641         // Notify connected clients logged in as the user of the new access level
 642         for _, c := range cc.Server.Clients {
 643                 if c.Account.Login == login {
 644                         // Note: comment out these two lines to test server-side deny messages
 645                         newT := NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, newAccessLvl))
 646                         res = append(res, *newT)
 647
 648                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))
 649                         if authorize(c.Account.Access, accessDisconUser) {
 650                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 1)
 651                         } else {
 652                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 0)
 653                         }
 654                         binary.BigEndian.PutUint16(*c.Flags, uint16(flagBitmap.Int64()))
 655
 656                         c.Account.Access = account.Access
 657
 658                         cc.sendAll(
 659                                 tranNotifyChangeUser,
 660                                 NewField(fieldUserID, *c.ID),
 661                                 NewField(fieldUserFlags, *c.Flags),
 662                                 NewField(fieldUserName, c.UserName),
 663                                 NewField(fieldUserIconID, *c.Icon),
 664                         )
 665                 }
 666         }
 667
 668         res = append(res, cc.NewReply(t))
 669         return res, err
 670 }
 671
 672 func HandleGetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 673         if !authorize(cc.Account.Access, accessOpenUser) {
 674                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 675                 return res, err
 676         }
 677
 678         account := cc.Server.Accounts[string(t.GetField(fieldUserLogin).Data)]
 679         if account == nil {
 680                 res = append(res, cc.NewErrReply(t, "Account does not exist."))
 681                 return res, err
 682         }
 683
 684         res = append(res, cc.NewReply(t,
 685                 NewField(fieldUserName, []byte(account.Name)),
 686                 NewField(fieldUserLogin, negateString(t.GetField(fieldUserLogin).Data)),
 687                 NewField(fieldUserPassword, []byte(account.Password)),
 688                 NewField(fieldUserAccess, *account.Access),
 689         ))
 690         return res, err
 691 }
 692
 693 func HandleListUsers(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 694         if !authorize(cc.Account.Access, accessOpenUser) {
 695                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 696                 return res, err
 697         }
 698
 699         var userFields []Field
 700         for _, acc := range cc.Server.Accounts {
 701                 userField := acc.MarshalBinary()
 702                 userFields = append(userFields, NewField(fieldData, userField))
 703         }
 704
 705         res = append(res, cc.NewReply(t, userFields...))
 706         return res, err
 707 }
 708
 709 // HandleUpdateUser is used by the v1.5+ multi-user editor to perform account editing for multiple users at a time.
 710 // An update can be a mix of these actions:
 711 // * Create user
 712 // * Delete user
 713 // * Modify user (including renaming the account login)
 714 //
 715 // The Transaction sent by the client includes one data field per user that was modified.  This data field in turn
 716 // contains another data field encoded in its payload with a varying number of sub fields depending on which action is
 717 // performed.  This seems to be the only place in the Hotline protocol where a data field contains another data field.
 718 func HandleUpdateUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 719         for _, field := range t.Fields {
 720                 subFields, err := ReadFields(field.Data[0:2], field.Data[2:])
 721                 if err != nil {
 722                         return res, err
 723                 }
 724
 725                 if len(subFields) == 1 {
 726                         login := DecodeUserString(getField(fieldData, &subFields).Data)
 727                         cc.logger.Infow("DeleteUser", "login", login)
 728
 729                         if !authorize(cc.Account.Access, accessDeleteUser) {
 730                                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 731                                 return res, err
 732                         }
 733
 734                         if err := cc.Server.DeleteUser(login); err != nil {
 735                                 return res, err
 736                         }
 737                         continue
 738                 }
 739
 740                 login := DecodeUserString(getField(fieldUserLogin, &subFields).Data)
 741
 742                 // check if the login dataFile; if so, we know we are updating an existing user
 743                 if acc, ok := cc.Server.Accounts[login]; ok {
 744                         cc.logger.Infow("UpdateUser", "login", login)
 745
 746                         // account dataFile, so this is an update action
 747                         if !authorize(cc.Account.Access, accessModifyUser) {
 748                                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 749                                 return res, err
 750                         }
 751
 752                         if getField(fieldUserPassword, &subFields) != nil {
 753                                 newPass := getField(fieldUserPassword, &subFields).Data
 754                                 acc.Password = hashAndSalt(newPass)
 755                         } else {
 756                                 acc.Password = hashAndSalt([]byte(""))
 757                         }
 758
 759                         if getField(fieldUserAccess, &subFields) != nil {
 760                                 acc.Access = &getField(fieldUserAccess, &subFields).Data
 761                         }
 762
 763                         err = cc.Server.UpdateUser(
 764                                 DecodeUserString(getField(fieldData, &subFields).Data),
 765                                 DecodeUserString(getField(fieldUserLogin, &subFields).Data),
 766                                 string(getField(fieldUserName, &subFields).Data),
 767                                 acc.Password,
 768                                 *acc.Access,
 769                         )
 770                         if err != nil {
 771                                 return res, err
 772                         }
 773                 } else {
 774                         cc.logger.Infow("CreateUser", "login", login)
 775
 776                         if !authorize(cc.Account.Access, accessCreateUser) {
 777                                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 778                                 return res, err
 779                         }
 780
 781                         err := cc.Server.NewUser(
 782                                 login,
 783                                 string(getField(fieldUserName, &subFields).Data),
 784                                 string(getField(fieldUserPassword, &subFields).Data),
 785                                 getField(fieldUserAccess, &subFields).Data,
 786                         )
 787                         if err != nil {
 788                                 return []Transaction{}, err
 789                         }
 790                 }
 791         }
 792
 793         res = append(res, cc.NewReply(t))
 794         return res, err
 795 }
 796
 797 // HandleNewUser creates a new user account
 798 func HandleNewUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 799         if !authorize(cc.Account.Access, accessCreateUser) {
 800                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 801                 return res, err
 802         }
 803
 804         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 805
 806         // If the account already dataFile, reply with an error
 807         if _, ok := cc.Server.Accounts[login]; ok {
 808                 res = append(res, cc.NewErrReply(t, "Cannot create account "+login+" because there is already an account with that login."))
 809                 return res, err
 810         }
 811
 812         if err := cc.Server.NewUser(
 813                 login,
 814                 string(t.GetField(fieldUserName).Data),
 815                 string(t.GetField(fieldUserPassword).Data),
 816                 t.GetField(fieldUserAccess).Data,
 817         ); err != nil {
 818                 return []Transaction{}, err
 819         }
 820
 821         res = append(res, cc.NewReply(t))
 822         return res, err
 823 }
 824
 825 func HandleDeleteUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 826         if !authorize(cc.Account.Access, accessDeleteUser) {
 827                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 828                 return res, err
 829         }
 830
 831         // TODO: Handle case where account doesn't exist; e.g. delete race condition
 832         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 833
 834         if err := cc.Server.DeleteUser(login); err != nil {
 835                 return res, err
 836         }
 837
 838         res = append(res, cc.NewReply(t))
 839         return res, err
 840 }
 841
 842 // HandleUserBroadcast sends an Administrator Message to all connected clients of the server
 843 func HandleUserBroadcast(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 844         if !authorize(cc.Account.Access, accessBroadcast) {
 845                 res = append(res, cc.NewErrReply(t, "You are not allowed to send broadcast messages."))
 846                 return res, err
 847         }
 848
 849         cc.sendAll(
 850                 tranServerMsg,
 851                 NewField(fieldData, t.GetField(tranGetMsgs).Data),
 852                 NewField(fieldChatOptions, []byte{0}),
 853         )
 854
 855         res = append(res, cc.NewReply(t))
 856         return res, err
 857 }
 858
 859 func byteToInt(bytes []byte) (int, error) {
 860         switch len(bytes) {
 861         case 2:
 862                 return int(binary.BigEndian.Uint16(bytes)), nil
 863         case 4:
 864                 return int(binary.BigEndian.Uint32(bytes)), nil
 865         }
 866
 867         return 0, errors.New("unknown byte length")
 868 }
 869
 870 // HandleGetClientInfoText returns user information for the specific user.
 871 //
 872 // Fields used in the request:
 873 // 103  User ID
 874 //
 875 // Fields used in the reply:
 876 // 102  User name
 877 // 101  Data            User info text string
 878 func HandleGetClientInfoText(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 879         if !authorize(cc.Account.Access, accessGetClientInfo) {
 880                 res = append(res, cc.NewErrReply(t, "You are not allowed to get client info."))
 881                 return res, err
 882         }
 883
 884         clientID, _ := byteToInt(t.GetField(fieldUserID).Data)
 885
 886         clientConn := cc.Server.Clients[uint16(clientID)]
 887         if clientConn == nil {
 888                 return append(res, cc.NewErrReply(t, "User not found.")), err
 889         }
 890
 891         res = append(res, cc.NewReply(t,
 892                 NewField(fieldData, []byte(clientConn.String())),
 893                 NewField(fieldUserName, clientConn.UserName),
 894         ))
 895         return res, err
 896 }
 897
 898 func HandleGetUserNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 899         res = append(res, cc.NewReply(t, cc.Server.connectedUsers()...))
 900
 901         return res, err
 902 }
 903
 904 func HandleTranAgreed(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 905         cc.Agreed = true
 906         cc.UserName = t.GetField(fieldUserName).Data
 907         *cc.Icon = t.GetField(fieldUserIconID).Data
 908
 909         cc.logger = cc.logger.With("name", string(cc.UserName))
 910
 911         options := t.GetField(fieldOptions).Data
 912         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 913
 914         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
 915
 916         // Check refuse private PM option
 917         if optBitmap.Bit(refusePM) == 1 {
 918                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, 1)
 919                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 920         }
 921
 922         // Check refuse private chat option
 923         if optBitmap.Bit(refuseChat) == 1 {
 924                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, 1)
 925                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 926         }
 927
 928         // Check auto response
 929         if optBitmap.Bit(autoResponse) == 1 {
 930                 cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
 931         } else {
 932                 cc.AutoReply = []byte{}
 933         }
 934
 935         for _, t := range cc.notifyOthers(
 936                 *NewTransaction(
 937                         tranNotifyChangeUser, nil,
 938                         NewField(fieldUserName, cc.UserName),
 939                         NewField(fieldUserID, *cc.ID),
 940                         NewField(fieldUserIconID, *cc.Icon),
 941                         NewField(fieldUserFlags, *cc.Flags),
 942                 ),
 943         ) {
 944                 cc.Server.outbox <- t
 945         }
 946
 947         if cc.Server.Config.BannerFile != "" {
 948                 cc.Server.outbox <- *NewTransaction(tranServerBanner, cc.ID, NewField(fieldBannerType, []byte("JPEG")))
 949         }
 950
 951         res = append(res, cc.NewReply(t))
 952
 953         return res, err
 954 }
 955
 956 const defaultNewsDateFormat = "Jan02 15:04" // Jun23 20:49
 957 //  "Mon, 02 Jan 2006 15:04:05 MST"
 958
 959 const defaultNewsTemplate = `From %s (%s):
 960
 961 %s
 962
 963 __________________________________________________________`
 964
 965 // HandleTranOldPostNews updates the flat news
 966 // Fields used in this request:
 967 // 101  Data
 968 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 969         if !authorize(cc.Account.Access, accessNewsPostArt) {
 970                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
 971                 return res, err
 972         }
 973
 974         cc.Server.flatNewsMux.Lock()
 975         defer cc.Server.flatNewsMux.Unlock()
 976
 977         newsDateTemplate := defaultNewsDateFormat
 978         if cc.Server.Config.NewsDateFormat != "" {
 979                 newsDateTemplate = cc.Server.Config.NewsDateFormat
 980         }
 981
 982         newsTemplate := defaultNewsTemplate
 983         if cc.Server.Config.NewsDelimiter != "" {
 984                 newsTemplate = cc.Server.Config.NewsDelimiter
 985         }
 986
 987         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(fieldData).Data)
 988         newsPost = strings.Replace(newsPost, "\n", "\r", -1)
 989
 990         // update news in memory
 991         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
 992
 993         // update news on disk
 994         if err := ioutil.WriteFile(cc.Server.ConfigDir+"MessageBoard.txt", cc.Server.FlatNews, 0644); err != nil {
 995                 return res, err
 996         }
 997
 998         // Notify all clients of updated news
 999         cc.sendAll(
1000                 tranNewMsg,
1001                 NewField(fieldData, []byte(newsPost)),
1002         )
1003
1004         res = append(res, cc.NewReply(t))
1005         return res, err
1006 }
1007
1008 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1009         if !authorize(cc.Account.Access, accessDisconUser) {
1010                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1011                 return res, err
1012         }
1013
1014         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(fieldUserID).Data)]
1015
1016         if authorize(clientConn.Account.Access, accessCannotBeDiscon) {
1017                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1018                 return res, err
1019         }
1020
1021         if err := clientConn.Connection.Close(); err != nil {
1022                 return res, err
1023         }
1024
1025         res = append(res, cc.NewReply(t))
1026         return res, err
1027 }
1028
1029 // HandleGetNewsCatNameList returns a list of news categories for a path
1030 // Fields used in the request:
1031 // 325  News path       (Optional)
1032 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1033         if !authorize(cc.Account.Access, accessNewsReadArt) {
1034                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1035                 return res, err
1036         }
1037
1038         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1039         cats := cc.Server.GetNewsCatByPath(pathStrs)
1040
1041         // To store the keys in slice in sorted order
1042         keys := make([]string, len(cats))
1043         i := 0
1044         for k := range cats {
1045                 keys[i] = k
1046                 i++
1047         }
1048         sort.Strings(keys)
1049
1050         var fieldData []Field
1051         for _, k := range keys {
1052                 cat := cats[k]
1053                 b, _ := cat.MarshalBinary()
1054                 fieldData = append(fieldData, NewField(
1055                         fieldNewsCatListData15,
1056                         b,
1057                 ))
1058         }
1059
1060         res = append(res, cc.NewReply(t, fieldData...))
1061         return res, err
1062 }
1063
1064 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1065         if !authorize(cc.Account.Access, accessNewsCreateCat) {
1066                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1067                 return res, err
1068         }
1069
1070         name := string(t.GetField(fieldNewsCatName).Data)
1071         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1072
1073         cats := cc.Server.GetNewsCatByPath(pathStrs)
1074         cats[name] = NewsCategoryListData15{
1075                 Name:     name,
1076                 Type:     []byte{0, 3},
1077                 Articles: map[uint32]*NewsArtData{},
1078                 SubCats:  make(map[string]NewsCategoryListData15),
1079         }
1080
1081         if err := cc.Server.writeThreadedNews(); err != nil {
1082                 return res, err
1083         }
1084         res = append(res, cc.NewReply(t))
1085         return res, err
1086 }
1087
1088 // Fields used in the request:
1089 // 322  News category name
1090 // 325  News path
1091 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1092         if !authorize(cc.Account.Access, accessNewsCreateFldr) {
1093                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1094                 return res, err
1095         }
1096
1097         name := string(t.GetField(fieldFileName).Data)
1098         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1099
1100         cc.logger.Infof("Creating new news folder %s", name)
1101
1102         cats := cc.Server.GetNewsCatByPath(pathStrs)
1103         cats[name] = NewsCategoryListData15{
1104                 Name:     name,
1105                 Type:     []byte{0, 2},
1106                 Articles: map[uint32]*NewsArtData{},
1107                 SubCats:  make(map[string]NewsCategoryListData15),
1108         }
1109         if err := cc.Server.writeThreadedNews(); err != nil {
1110                 return res, err
1111         }
1112         res = append(res, cc.NewReply(t))
1113         return res, err
1114 }
1115
1116 // Fields used in the request:
1117 // 325  News path       Optional
1118 //
1119 // Reply fields:
1120 // 321  News article list data  Optional
1121 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1122         if !authorize(cc.Account.Access, accessNewsReadArt) {
1123                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1124                 return res, err
1125         }
1126         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1127
1128         var cat NewsCategoryListData15
1129         cats := cc.Server.ThreadedNews.Categories
1130
1131         for _, fp := range pathStrs {
1132                 cat = cats[fp]
1133                 cats = cats[fp].SubCats
1134         }
1135
1136         nald := cat.GetNewsArtListData()
1137
1138         res = append(res, cc.NewReply(t, NewField(fieldNewsArtListData, nald.Payload())))
1139         return res, err
1140 }
1141
1142 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1143         if !authorize(cc.Account.Access, accessNewsReadArt) {
1144                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1145                 return res, err
1146         }
1147
1148         // Request fields
1149         // 325  News fp
1150         // 326  News article ID
1151         // 327  News article data flavor
1152
1153         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1154
1155         var cat NewsCategoryListData15
1156         cats := cc.Server.ThreadedNews.Categories
1157
1158         for _, fp := range pathStrs {
1159                 cat = cats[fp]
1160                 cats = cats[fp].SubCats
1161         }
1162         newsArtID := t.GetField(fieldNewsArtID).Data
1163
1164         convertedArtID := binary.BigEndian.Uint16(newsArtID)
1165
1166         art := cat.Articles[uint32(convertedArtID)]
1167         if art == nil {
1168                 res = append(res, cc.NewReply(t))
1169                 return res, err
1170         }
1171
1172         // Reply fields
1173         // 328  News article title
1174         // 329  News article poster
1175         // 330  News article date
1176         // 331  Previous article ID
1177         // 332  Next article ID
1178         // 335  Parent article ID
1179         // 336  First child article ID
1180         // 327  News article data flavor        "Should be “text/plain”
1181         // 333  News article data       Optional (if data flavor is “text/plain”)
1182
1183         res = append(res, cc.NewReply(t,
1184                 NewField(fieldNewsArtTitle, []byte(art.Title)),
1185                 NewField(fieldNewsArtPoster, []byte(art.Poster)),
1186                 NewField(fieldNewsArtDate, art.Date),
1187                 NewField(fieldNewsArtPrevArt, art.PrevArt),
1188                 NewField(fieldNewsArtNextArt, art.NextArt),
1189                 NewField(fieldNewsArtParentArt, art.ParentArt),
1190                 NewField(fieldNewsArt1stChildArt, art.FirstChildArt),
1191                 NewField(fieldNewsArtDataFlav, []byte("text/plain")),
1192                 NewField(fieldNewsArtData, []byte(art.Data)),
1193         ))
1194         return res, err
1195 }
1196
1197 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1198         // Has multiple access flags: News Delete Folder (37) or News Delete Category (35)
1199         // TODO: Implement
1200
1201         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1202
1203         // TODO: determine if path is a Folder (Bundle) or Category and check for permission
1204
1205         cc.logger.Infof("DelNewsItem %v", pathStrs)
1206
1207         cats := cc.Server.ThreadedNews.Categories
1208
1209         delName := pathStrs[len(pathStrs)-1]
1210         if len(pathStrs) > 1 {
1211                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1212                         cats = cats[fp].SubCats
1213                 }
1214         }
1215
1216         delete(cats, delName)
1217
1218         err = cc.Server.writeThreadedNews()
1219         if err != nil {
1220                 return res, err
1221         }
1222
1223         // Reply params: none
1224         res = append(res, cc.NewReply(t))
1225
1226         return res, err
1227 }
1228
1229 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1230         if !authorize(cc.Account.Access, accessNewsDeleteArt) {
1231                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1232                 return res, err
1233         }
1234
1235         // Request Fields
1236         // 325  News path
1237         // 326  News article ID
1238         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1239         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1240         ID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1241
1242         // TODO: Delete recursive
1243         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1244
1245         catName := pathStrs[len(pathStrs)-1]
1246         cat := cats[catName]
1247
1248         delete(cat.Articles, uint32(ID))
1249
1250         cats[catName] = cat
1251         if err := cc.Server.writeThreadedNews(); err != nil {
1252                 return res, err
1253         }
1254
1255         res = append(res, cc.NewReply(t))
1256         return res, err
1257 }
1258
1259 // Request fields
1260 // 325  News path
1261 // 326  News article ID                                                 ID of the parent article?
1262 // 328  News article title
1263 // 334  News article flags
1264 // 327  News article data flavor                Currently “text/plain”
1265 // 333  News article data
1266 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1267         if !authorize(cc.Account.Access, accessNewsPostArt) {
1268                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1269                 return res, err
1270         }
1271
1272         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1273         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1274
1275         catName := pathStrs[len(pathStrs)-1]
1276         cat := cats[catName]
1277
1278         newArt := NewsArtData{
1279                 Title:         string(t.GetField(fieldNewsArtTitle).Data),
1280                 Poster:        string(cc.UserName),
1281                 Date:          toHotlineTime(time.Now()),
1282                 PrevArt:       []byte{0, 0, 0, 0},
1283                 NextArt:       []byte{0, 0, 0, 0},
1284                 ParentArt:     append([]byte{0, 0}, t.GetField(fieldNewsArtID).Data...),
1285                 FirstChildArt: []byte{0, 0, 0, 0},
1286                 DataFlav:      []byte("text/plain"),
1287                 Data:          string(t.GetField(fieldNewsArtData).Data),
1288         }
1289
1290         var keys []int
1291         for k := range cat.Articles {
1292                 keys = append(keys, int(k))
1293         }
1294
1295         nextID := uint32(1)
1296         if len(keys) > 0 {
1297                 sort.Ints(keys)
1298                 prevID := uint32(keys[len(keys)-1])
1299                 nextID = prevID + 1
1300
1301                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1302
1303                 // Set next article ID
1304                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1305         }
1306
1307         // Update parent article with first child reply
1308         parentID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1309         if parentID != 0 {
1310                 parentArt := cat.Articles[uint32(parentID)]
1311
1312                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1313                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1314                 }
1315         }
1316
1317         cat.Articles[nextID] = &newArt
1318
1319         cats[catName] = cat
1320         if err := cc.Server.writeThreadedNews(); err != nil {
1321                 return res, err
1322         }
1323
1324         res = append(res, cc.NewReply(t))
1325         return res, err
1326 }
1327
1328 // HandleGetMsgs returns the flat news data
1329 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1330         if !authorize(cc.Account.Access, accessNewsReadArt) {
1331                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1332                 return res, err
1333         }
1334
1335         res = append(res, cc.NewReply(t, NewField(fieldData, cc.Server.FlatNews)))
1336
1337         return res, err
1338 }
1339
1340 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1341         if !authorize(cc.Account.Access, accessDownloadFile) {
1342                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1343                 return res, err
1344         }
1345
1346         fileName := t.GetField(fieldFileName).Data
1347         filePath := t.GetField(fieldFilePath).Data
1348         resumeData := t.GetField(fieldFileResumeData).Data
1349
1350         var dataOffset int64
1351         var frd FileResumeData
1352         if resumeData != nil {
1353                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1354                         return res, err
1355                 }
1356                 // TODO: handle rsrc fork offset
1357                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1358         }
1359
1360         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1361         if err != nil {
1362                 return res, err
1363         }
1364
1365         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1366         if err != nil {
1367                 return res, err
1368         }
1369
1370         xferSize := hlFile.ffo.TransferSize(0)
1371
1372         ft := cc.newFileTransfer(FileDownload, fileName, filePath, xferSize)
1373
1374         // TODO: refactor to remove this
1375         if resumeData != nil {
1376                 var frd FileResumeData
1377                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1378                         return res, err
1379                 }
1380                 ft.fileResumeData = &frd
1381         }
1382
1383         // Optional field for when a HL v1.5+ client requests file preview
1384         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1385         // The value will always be 2
1386         if t.GetField(fieldFileTransferOptions).Data != nil {
1387                 ft.options = t.GetField(fieldFileTransferOptions).Data
1388                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1389         }
1390
1391         res = append(res, cc.NewReply(t,
1392                 NewField(fieldRefNum, ft.refNum[:]),
1393                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1394                 NewField(fieldTransferSize, xferSize),
1395                 NewField(fieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1396         ))
1397
1398         return res, err
1399 }
1400
1401 // Download all files from the specified folder and sub-folders
1402 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1403         if !authorize(cc.Account.Access, accessDownloadFile) {
1404                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1405                 return res, err
1406         }
1407
1408         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
1409         if err != nil {
1410                 return res, err
1411         }
1412
1413         transferSize, err := CalcTotalSize(fullFilePath)
1414         if err != nil {
1415                 return res, err
1416         }
1417         itemCount, err := CalcItemCount(fullFilePath)
1418         if err != nil {
1419                 return res, err
1420         }
1421
1422         fileTransfer := cc.newFileTransfer(FolderDownload, t.GetField(fieldFileName).Data, t.GetField(fieldFilePath).Data, transferSize)
1423
1424         var fp FilePath
1425         err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
1426         if err != nil {
1427                 return res, err
1428         }
1429
1430         res = append(res, cc.NewReply(t,
1431                 NewField(fieldRefNum, fileTransfer.ReferenceNumber),
1432                 NewField(fieldTransferSize, transferSize),
1433                 NewField(fieldFolderItemCount, itemCount),
1434                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1435         ))
1436         return res, err
1437 }
1438
1439 // Upload all files from the local folder and its subfolders to the specified path on the server
1440 // Fields used in the request
1441 // 201  File name
1442 // 202  File path
1443 // 108  transfer size   Total size of all items in the folder
1444 // 220  Folder item count
1445 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1446 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1447         var fp FilePath
1448         if t.GetField(fieldFilePath).Data != nil {
1449                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1450                         return res, err
1451                 }
1452         }
1453
1454         // Handle special cases for Upload and Drop Box folders
1455         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1456                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1457                         res = append(res, cc.NewErrReply(t, fmt.Sprintf("Cannot accept upload of the folder \"%v\" because you are only allowed to upload to the \"Uploads\" folder.", string(t.GetField(fieldFileName).Data))))
1458                         return res, err
1459                 }
1460         }
1461
1462         fileTransfer := cc.newFileTransfer(FolderUpload,
1463                 t.GetField(fieldFileName).Data,
1464                 t.GetField(fieldFilePath).Data,
1465                 t.GetField(fieldTransferSize).Data,
1466         )
1467
1468         fileTransfer.FolderItemCount = t.GetField(fieldFolderItemCount).Data
1469
1470         res = append(res, cc.NewReply(t, NewField(fieldRefNum, fileTransfer.ReferenceNumber)))
1471         return res, err
1472 }
1473
1474 // HandleUploadFile
1475 // Fields used in the request:
1476 // 201  File name
1477 // 202  File path
1478 // 204  File transfer options   "Optional
1479 // Used only to resume download, currently has value 2"
1480 // 108  File transfer size      "Optional used if download is not resumed"
1481 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1482         if !authorize(cc.Account.Access, accessUploadFile) {
1483                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1484                 return res, err
1485         }
1486
1487         fileName := t.GetField(fieldFileName).Data
1488         filePath := t.GetField(fieldFilePath).Data
1489         transferOptions := t.GetField(fieldFileTransferOptions).Data
1490         transferSize := t.GetField(fieldTransferSize).Data // not sent for resume
1491
1492         var fp FilePath
1493         if filePath != nil {
1494                 if err = fp.UnmarshalBinary(filePath); err != nil {
1495                         return res, err
1496                 }
1497         }
1498
1499         // Handle special cases for Upload and Drop Box folders
1500         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1501                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1502                         res = append(res, cc.NewErrReply(t, fmt.Sprintf("Cannot accept upload of the file \"%v\" because you are only allowed to upload to the \"Uploads\" folder.", string(fileName))))
1503                         return res, err
1504                 }
1505         }
1506         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1507         if err != nil {
1508                 return res, err
1509         }
1510
1511         if _, err := cc.Server.FS.Stat(fullFilePath); err == nil {
1512                 res = append(res, cc.NewErrReply(t, fmt.Sprintf("Cannot accept upload because there is already a file named \"%v\".  Try choosing a different name.", string(fileName))))
1513                 return res, err
1514         }
1515
1516         ft := cc.newFileTransfer(FileUpload, fileName, filePath, transferSize)
1517
1518         replyT := cc.NewReply(t, NewField(fieldRefNum, ft.ReferenceNumber))
1519
1520         // client has requested to resume a partially transferred file
1521         if transferOptions != nil {
1522
1523                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1524                 if err != nil {
1525                         return res, err
1526                 }
1527
1528                 offset := make([]byte, 4)
1529                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1530
1531                 fileResumeData := NewFileResumeData([]ForkInfoList{
1532                         *NewForkInfoList(offset),
1533                 })
1534
1535                 b, _ := fileResumeData.BinaryMarshal()
1536
1537                 ft.TransferSize = offset
1538
1539                 replyT.Fields = append(replyT.Fields, NewField(fieldFileResumeData, b))
1540         }
1541
1542         res = append(res, replyT)
1543         return res, err
1544 }
1545
1546 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1547         var icon []byte
1548         if len(t.GetField(fieldUserIconID).Data) == 4 {
1549                 icon = t.GetField(fieldUserIconID).Data[2:]
1550         } else {
1551                 icon = t.GetField(fieldUserIconID).Data
1552         }
1553         *cc.Icon = icon
1554         cc.UserName = t.GetField(fieldUserName).Data
1555
1556         // the options field is only passed by the client versions > 1.2.3.
1557         options := t.GetField(fieldOptions).Data
1558
1559         if options != nil {
1560                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1561                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
1562
1563                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, optBitmap.Bit(refusePM))
1564                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1565
1566                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, optBitmap.Bit(refuseChat))
1567                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1568
1569                 // Check auto response
1570                 if optBitmap.Bit(autoResponse) == 1 {
1571                         cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
1572                 } else {
1573                         cc.AutoReply = []byte{}
1574                 }
1575         }
1576
1577         // Notify all clients of updated user info
1578         cc.sendAll(
1579                 tranNotifyChangeUser,
1580                 NewField(fieldUserID, *cc.ID),
1581                 NewField(fieldUserIconID, *cc.Icon),
1582                 NewField(fieldUserFlags, *cc.Flags),
1583                 NewField(fieldUserName, cc.UserName),
1584         )
1585
1586         return res, err
1587 }
1588
1589 // HandleKeepAlive responds to keepalive transactions with an empty reply
1590 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1591 // * HL 1.2.3 Client doesn't send keepalives
1592 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1593         res = append(res, cc.NewReply(t))
1594
1595         return res, err
1596 }
1597
1598 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1599         fullPath, err := readPath(
1600                 cc.Server.Config.FileRoot,
1601                 t.GetField(fieldFilePath).Data,
1602                 nil,
1603         )
1604         if err != nil {
1605                 return res, err
1606         }
1607
1608         var fp FilePath
1609         if t.GetField(fieldFilePath).Data != nil {
1610                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1611                         return res, err
1612                 }
1613         }
1614
1615         // Handle special case for drop box folders
1616         if fp.IsDropbox() && !authorize(cc.Account.Access, accessViewDropBoxes) {
1617                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1618                 return res, err
1619         }
1620
1621         fileNames, err := getFileNameList(fullPath)
1622         if err != nil {
1623                 return res, err
1624         }
1625
1626         res = append(res, cc.NewReply(t, fileNames...))
1627
1628         return res, err
1629 }
1630
1631 // =================================
1632 //     Hotline private chat flow
1633 // =================================
1634 // 1. ClientA sends tranInviteNewChat to server with user ID to invite
1635 // 2. Server creates new ChatID
1636 // 3. Server sends tranInviteToChat to invitee
1637 // 4. Server replies to ClientA with new Chat ID
1638 //
1639 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1640 // If Accepted is clicked:
1641 // 1. ClientB sends tranJoinChat with fieldChatID
1642
1643 // HandleInviteNewChat invites users to new private chat
1644 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1645         if !authorize(cc.Account.Access, accessOpenChat) {
1646                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1647                 return res, err
1648         }
1649
1650         // Client to Invite
1651         targetID := t.GetField(fieldUserID).Data
1652         newChatID := cc.Server.NewPrivateChat(cc)
1653
1654         res = append(res,
1655                 *NewTransaction(
1656                         tranInviteToChat,
1657                         &targetID,
1658                         NewField(fieldChatID, newChatID),
1659                         NewField(fieldUserName, cc.UserName),
1660                         NewField(fieldUserID, *cc.ID),
1661                 ),
1662         )
1663
1664         res = append(res,
1665                 cc.NewReply(t,
1666                         NewField(fieldChatID, newChatID),
1667                         NewField(fieldUserName, cc.UserName),
1668                         NewField(fieldUserID, *cc.ID),
1669                         NewField(fieldUserIconID, *cc.Icon),
1670                         NewField(fieldUserFlags, *cc.Flags),
1671                 ),
1672         )
1673
1674         return res, err
1675 }
1676
1677 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1678         if !authorize(cc.Account.Access, accessOpenChat) {
1679                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1680                 return res, err
1681         }
1682
1683         // Client to Invite
1684         targetID := t.GetField(fieldUserID).Data
1685         chatID := t.GetField(fieldChatID).Data
1686
1687         res = append(res,
1688                 *NewTransaction(
1689                         tranInviteToChat,
1690                         &targetID,
1691                         NewField(fieldChatID, chatID),
1692                         NewField(fieldUserName, cc.UserName),
1693                         NewField(fieldUserID, *cc.ID),
1694                 ),
1695         )
1696         res = append(res,
1697                 cc.NewReply(
1698                         t,
1699                         NewField(fieldChatID, chatID),
1700                         NewField(fieldUserName, cc.UserName),
1701                         NewField(fieldUserID, *cc.ID),
1702                         NewField(fieldUserIconID, *cc.Icon),
1703                         NewField(fieldUserFlags, *cc.Flags),
1704                 ),
1705         )
1706
1707         return res, err
1708 }
1709
1710 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1711         chatID := t.GetField(fieldChatID).Data
1712         chatInt := binary.BigEndian.Uint32(chatID)
1713
1714         privChat := cc.Server.PrivateChats[chatInt]
1715
1716         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1717
1718         for _, c := range sortedClients(privChat.ClientConn) {
1719                 res = append(res,
1720                         *NewTransaction(
1721                                 tranChatMsg,
1722                                 c.ID,
1723                                 NewField(fieldChatID, chatID),
1724                                 NewField(fieldData, resMsg),
1725                         ),
1726                 )
1727         }
1728
1729         return res, err
1730 }
1731
1732 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1733 // Fields used in the reply:
1734 // * 115        Chat subject
1735 // * 300        User name with info (Optional)
1736 // * 300        (more user names with info)
1737 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1738         chatID := t.GetField(fieldChatID).Data
1739         chatInt := binary.BigEndian.Uint32(chatID)
1740
1741         privChat := cc.Server.PrivateChats[chatInt]
1742
1743         // Send tranNotifyChatChangeUser to current members of the chat to inform of new user
1744         for _, c := range sortedClients(privChat.ClientConn) {
1745                 res = append(res,
1746                         *NewTransaction(
1747                                 tranNotifyChatChangeUser,
1748                                 c.ID,
1749                                 NewField(fieldChatID, chatID),
1750                                 NewField(fieldUserName, cc.UserName),
1751                                 NewField(fieldUserID, *cc.ID),
1752                                 NewField(fieldUserIconID, *cc.Icon),
1753                                 NewField(fieldUserFlags, *cc.Flags),
1754                         ),
1755                 )
1756         }
1757
1758         privChat.ClientConn[cc.uint16ID()] = cc
1759
1760         replyFields := []Field{NewField(fieldChatSubject, []byte(privChat.Subject))}
1761         for _, c := range sortedClients(privChat.ClientConn) {
1762                 user := User{
1763                         ID:    *c.ID,
1764                         Icon:  *c.Icon,
1765                         Flags: *c.Flags,
1766                         Name:  string(c.UserName),
1767                 }
1768
1769                 replyFields = append(replyFields, NewField(fieldUsernameWithInfo, user.Payload()))
1770         }
1771
1772         res = append(res, cc.NewReply(t, replyFields...))
1773         return res, err
1774 }
1775
1776 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1777 // Fields used in the request:
1778 //      * 114   fieldChatID
1779 // Reply is not expected.
1780 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1781         chatID := t.GetField(fieldChatID).Data
1782         chatInt := binary.BigEndian.Uint32(chatID)
1783
1784         privChat := cc.Server.PrivateChats[chatInt]
1785
1786         delete(privChat.ClientConn, cc.uint16ID())
1787
1788         // Notify members of the private chat that the user has left
1789         for _, c := range sortedClients(privChat.ClientConn) {
1790                 res = append(res,
1791                         *NewTransaction(
1792                                 tranNotifyChatDeleteUser,
1793                                 c.ID,
1794                                 NewField(fieldChatID, chatID),
1795                                 NewField(fieldUserID, *cc.ID),
1796                         ),
1797                 )
1798         }
1799
1800         return res, err
1801 }
1802
1803 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1804 // Fields used in the request:
1805 // * 114        Chat ID
1806 // * 115        Chat subject    Chat subject string
1807 // Reply is not expected.
1808 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1809         chatID := t.GetField(fieldChatID).Data
1810         chatInt := binary.BigEndian.Uint32(chatID)
1811
1812         privChat := cc.Server.PrivateChats[chatInt]
1813         privChat.Subject = string(t.GetField(fieldChatSubject).Data)
1814
1815         for _, c := range sortedClients(privChat.ClientConn) {
1816                 res = append(res,
1817                         *NewTransaction(
1818                                 tranNotifyChatSubject,
1819                                 c.ID,
1820                                 NewField(fieldChatID, chatID),
1821                                 NewField(fieldChatSubject, t.GetField(fieldChatSubject).Data),
1822                         ),
1823                 )
1824         }
1825
1826         return res, err
1827 }
1828
1829 // HandleMakeAlias makes a filer alias using the specified path.
1830 // Fields used in the request:
1831 // 201  File name
1832 // 202  File path
1833 // 212  File new path   Destination path
1834 //
1835 // Fields used in the reply:
1836 // None
1837 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1838         if !authorize(cc.Account.Access, accessMakeAlias) {
1839                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1840                 return res, err
1841         }
1842         fileName := t.GetField(fieldFileName).Data
1843         filePath := t.GetField(fieldFilePath).Data
1844         fileNewPath := t.GetField(fieldFileNewPath).Data
1845
1846         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1847         if err != nil {
1848                 return res, err
1849         }
1850
1851         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1852         if err != nil {
1853                 return res, err
1854         }
1855
1856         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1857
1858         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
1859                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
1860                 return res, nil
1861         }
1862
1863         res = append(res, cc.NewReply(t))
1864         return res, err
1865 }
1866
1867 func HandleDownloadBanner(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1868         fi, err := cc.Server.FS.Stat(filepath.Join(cc.Server.ConfigDir, cc.Server.Config.BannerFile))
1869         if err != nil {
1870                 return res, err
1871         }
1872
1873         ft := cc.newFileTransfer(bannerDownload, []byte{}, []byte{}, make([]byte, 4))
1874
1875         binary.BigEndian.PutUint32(ft.TransferSize, uint32(fi.Size()))
1876
1877         res = append(res, cc.NewReply(t,
1878                 NewField(fieldRefNum, ft.refNum[:]),
1879                 NewField(fieldTransferSize, ft.TransferSize),
1880         ))
1881
1882         return res, err
1883 }