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         cc.logger.Infow("Login successful", "clientVersion", fmt.Sprintf("%x", *cc.Version))
 911
 912         options := t.GetField(fieldOptions).Data
 913         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 914
 915         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
 916
 917         // Check refuse private PM option
 918         if optBitmap.Bit(refusePM) == 1 {
 919                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, 1)
 920                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 921         }
 922
 923         // Check refuse private chat option
 924         if optBitmap.Bit(refuseChat) == 1 {
 925                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, 1)
 926                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 927         }
 928
 929         // Check auto response
 930         if optBitmap.Bit(autoResponse) == 1 {
 931                 cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
 932         } else {
 933                 cc.AutoReply = []byte{}
 934         }
 935
 936         for _, t := range cc.notifyOthers(
 937                 *NewTransaction(
 938                         tranNotifyChangeUser, nil,
 939                         NewField(fieldUserName, cc.UserName),
 940                         NewField(fieldUserID, *cc.ID),
 941                         NewField(fieldUserIconID, *cc.Icon),
 942                         NewField(fieldUserFlags, *cc.Flags),
 943                 ),
 944         ) {
 945                 cc.Server.outbox <- t
 946         }
 947
 948         if cc.Server.Config.BannerFile != "" {
 949                 cc.Server.outbox <- *NewTransaction(tranServerBanner, cc.ID, NewField(fieldBannerType, []byte("JPEG")))
 950         }
 951
 952         res = append(res, cc.NewReply(t))
 953
 954         return res, err
 955 }
 956
 957 const defaultNewsDateFormat = "Jan02 15:04" // Jun23 20:49
 958 //  "Mon, 02 Jan 2006 15:04:05 MST"
 959
 960 const defaultNewsTemplate = `From %s (%s):
 961
 962 %s
 963
 964 __________________________________________________________`
 965
 966 // HandleTranOldPostNews updates the flat news
 967 // Fields used in this request:
 968 // 101  Data
 969 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 970         if !authorize(cc.Account.Access, accessNewsPostArt) {
 971                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
 972                 return res, err
 973         }
 974
 975         cc.Server.flatNewsMux.Lock()
 976         defer cc.Server.flatNewsMux.Unlock()
 977
 978         newsDateTemplate := defaultNewsDateFormat
 979         if cc.Server.Config.NewsDateFormat != "" {
 980                 newsDateTemplate = cc.Server.Config.NewsDateFormat
 981         }
 982
 983         newsTemplate := defaultNewsTemplate
 984         if cc.Server.Config.NewsDelimiter != "" {
 985                 newsTemplate = cc.Server.Config.NewsDelimiter
 986         }
 987
 988         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(fieldData).Data)
 989         newsPost = strings.Replace(newsPost, "\n", "\r", -1)
 990
 991         // update news in memory
 992         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
 993
 994         // update news on disk
 995         if err := ioutil.WriteFile(cc.Server.ConfigDir+"MessageBoard.txt", cc.Server.FlatNews, 0644); err != nil {
 996                 return res, err
 997         }
 998
 999         // Notify all clients of updated news
1000         cc.sendAll(
1001                 tranNewMsg,
1002                 NewField(fieldData, []byte(newsPost)),
1003         )
1004
1005         res = append(res, cc.NewReply(t))
1006         return res, err
1007 }
1008
1009 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1010         if !authorize(cc.Account.Access, accessDisconUser) {
1011                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1012                 return res, err
1013         }
1014
1015         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(fieldUserID).Data)]
1016
1017         if authorize(clientConn.Account.Access, accessCannotBeDiscon) {
1018                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1019                 return res, err
1020         }
1021
1022         if err := clientConn.Connection.Close(); err != nil {
1023                 return res, err
1024         }
1025
1026         res = append(res, cc.NewReply(t))
1027         return res, err
1028 }
1029
1030 // HandleGetNewsCatNameList returns a list of news categories for a path
1031 // Fields used in the request:
1032 // 325  News path       (Optional)
1033 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1034         if !authorize(cc.Account.Access, accessNewsReadArt) {
1035                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1036                 return res, err
1037         }
1038
1039         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1040         cats := cc.Server.GetNewsCatByPath(pathStrs)
1041
1042         // To store the keys in slice in sorted order
1043         keys := make([]string, len(cats))
1044         i := 0
1045         for k := range cats {
1046                 keys[i] = k
1047                 i++
1048         }
1049         sort.Strings(keys)
1050
1051         var fieldData []Field
1052         for _, k := range keys {
1053                 cat := cats[k]
1054                 b, _ := cat.MarshalBinary()
1055                 fieldData = append(fieldData, NewField(
1056                         fieldNewsCatListData15,
1057                         b,
1058                 ))
1059         }
1060
1061         res = append(res, cc.NewReply(t, fieldData...))
1062         return res, err
1063 }
1064
1065 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1066         if !authorize(cc.Account.Access, accessNewsCreateCat) {
1067                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1068                 return res, err
1069         }
1070
1071         name := string(t.GetField(fieldNewsCatName).Data)
1072         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1073
1074         cats := cc.Server.GetNewsCatByPath(pathStrs)
1075         cats[name] = NewsCategoryListData15{
1076                 Name:     name,
1077                 Type:     []byte{0, 3},
1078                 Articles: map[uint32]*NewsArtData{},
1079                 SubCats:  make(map[string]NewsCategoryListData15),
1080         }
1081
1082         if err := cc.Server.writeThreadedNews(); err != nil {
1083                 return res, err
1084         }
1085         res = append(res, cc.NewReply(t))
1086         return res, err
1087 }
1088
1089 // Fields used in the request:
1090 // 322  News category name
1091 // 325  News path
1092 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1093         if !authorize(cc.Account.Access, accessNewsCreateFldr) {
1094                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1095                 return res, err
1096         }
1097
1098         name := string(t.GetField(fieldFileName).Data)
1099         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1100
1101         cc.logger.Infof("Creating new news folder %s", name)
1102
1103         cats := cc.Server.GetNewsCatByPath(pathStrs)
1104         cats[name] = NewsCategoryListData15{
1105                 Name:     name,
1106                 Type:     []byte{0, 2},
1107                 Articles: map[uint32]*NewsArtData{},
1108                 SubCats:  make(map[string]NewsCategoryListData15),
1109         }
1110         if err := cc.Server.writeThreadedNews(); err != nil {
1111                 return res, err
1112         }
1113         res = append(res, cc.NewReply(t))
1114         return res, err
1115 }
1116
1117 // Fields used in the request:
1118 // 325  News path       Optional
1119 //
1120 // Reply fields:
1121 // 321  News article list data  Optional
1122 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1123         if !authorize(cc.Account.Access, accessNewsReadArt) {
1124                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1125                 return res, err
1126         }
1127         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1128
1129         var cat NewsCategoryListData15
1130         cats := cc.Server.ThreadedNews.Categories
1131
1132         for _, fp := range pathStrs {
1133                 cat = cats[fp]
1134                 cats = cats[fp].SubCats
1135         }
1136
1137         nald := cat.GetNewsArtListData()
1138
1139         res = append(res, cc.NewReply(t, NewField(fieldNewsArtListData, nald.Payload())))
1140         return res, err
1141 }
1142
1143 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1144         if !authorize(cc.Account.Access, accessNewsReadArt) {
1145                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1146                 return res, err
1147         }
1148
1149         // Request fields
1150         // 325  News fp
1151         // 326  News article ID
1152         // 327  News article data flavor
1153
1154         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1155
1156         var cat NewsCategoryListData15
1157         cats := cc.Server.ThreadedNews.Categories
1158
1159         for _, fp := range pathStrs {
1160                 cat = cats[fp]
1161                 cats = cats[fp].SubCats
1162         }
1163         newsArtID := t.GetField(fieldNewsArtID).Data
1164
1165         convertedArtID := binary.BigEndian.Uint16(newsArtID)
1166
1167         art := cat.Articles[uint32(convertedArtID)]
1168         if art == nil {
1169                 res = append(res, cc.NewReply(t))
1170                 return res, err
1171         }
1172
1173         // Reply fields
1174         // 328  News article title
1175         // 329  News article poster
1176         // 330  News article date
1177         // 331  Previous article ID
1178         // 332  Next article ID
1179         // 335  Parent article ID
1180         // 336  First child article ID
1181         // 327  News article data flavor        "Should be “text/plain”
1182         // 333  News article data       Optional (if data flavor is “text/plain”)
1183
1184         res = append(res, cc.NewReply(t,
1185                 NewField(fieldNewsArtTitle, []byte(art.Title)),
1186                 NewField(fieldNewsArtPoster, []byte(art.Poster)),
1187                 NewField(fieldNewsArtDate, art.Date),
1188                 NewField(fieldNewsArtPrevArt, art.PrevArt),
1189                 NewField(fieldNewsArtNextArt, art.NextArt),
1190                 NewField(fieldNewsArtParentArt, art.ParentArt),
1191                 NewField(fieldNewsArt1stChildArt, art.FirstChildArt),
1192                 NewField(fieldNewsArtDataFlav, []byte("text/plain")),
1193                 NewField(fieldNewsArtData, []byte(art.Data)),
1194         ))
1195         return res, err
1196 }
1197
1198 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1199         // Has multiple access flags: News Delete Folder (37) or News Delete Category (35)
1200         // TODO: Implement
1201
1202         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1203
1204         // TODO: determine if path is a Folder (Bundle) or Category and check for permission
1205
1206         cc.logger.Infof("DelNewsItem %v", pathStrs)
1207
1208         cats := cc.Server.ThreadedNews.Categories
1209
1210         delName := pathStrs[len(pathStrs)-1]
1211         if len(pathStrs) > 1 {
1212                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1213                         cats = cats[fp].SubCats
1214                 }
1215         }
1216
1217         delete(cats, delName)
1218
1219         err = cc.Server.writeThreadedNews()
1220         if err != nil {
1221                 return res, err
1222         }
1223
1224         // Reply params: none
1225         res = append(res, cc.NewReply(t))
1226
1227         return res, err
1228 }
1229
1230 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1231         if !authorize(cc.Account.Access, accessNewsDeleteArt) {
1232                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1233                 return res, err
1234         }
1235
1236         // Request Fields
1237         // 325  News path
1238         // 326  News article ID
1239         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1240         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1241         ID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1242
1243         // TODO: Delete recursive
1244         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1245
1246         catName := pathStrs[len(pathStrs)-1]
1247         cat := cats[catName]
1248
1249         delete(cat.Articles, uint32(ID))
1250
1251         cats[catName] = cat
1252         if err := cc.Server.writeThreadedNews(); err != nil {
1253                 return res, err
1254         }
1255
1256         res = append(res, cc.NewReply(t))
1257         return res, err
1258 }
1259
1260 // Request fields
1261 // 325  News path
1262 // 326  News article ID                                                 ID of the parent article?
1263 // 328  News article title
1264 // 334  News article flags
1265 // 327  News article data flavor                Currently “text/plain”
1266 // 333  News article data
1267 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1268         if !authorize(cc.Account.Access, accessNewsPostArt) {
1269                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1270                 return res, err
1271         }
1272
1273         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1274         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1275
1276         catName := pathStrs[len(pathStrs)-1]
1277         cat := cats[catName]
1278
1279         newArt := NewsArtData{
1280                 Title:         string(t.GetField(fieldNewsArtTitle).Data),
1281                 Poster:        string(cc.UserName),
1282                 Date:          toHotlineTime(time.Now()),
1283                 PrevArt:       []byte{0, 0, 0, 0},
1284                 NextArt:       []byte{0, 0, 0, 0},
1285                 ParentArt:     append([]byte{0, 0}, t.GetField(fieldNewsArtID).Data...),
1286                 FirstChildArt: []byte{0, 0, 0, 0},
1287                 DataFlav:      []byte("text/plain"),
1288                 Data:          string(t.GetField(fieldNewsArtData).Data),
1289         }
1290
1291         var keys []int
1292         for k := range cat.Articles {
1293                 keys = append(keys, int(k))
1294         }
1295
1296         nextID := uint32(1)
1297         if len(keys) > 0 {
1298                 sort.Ints(keys)
1299                 prevID := uint32(keys[len(keys)-1])
1300                 nextID = prevID + 1
1301
1302                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1303
1304                 // Set next article ID
1305                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1306         }
1307
1308         // Update parent article with first child reply
1309         parentID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1310         if parentID != 0 {
1311                 parentArt := cat.Articles[uint32(parentID)]
1312
1313                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1314                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1315                 }
1316         }
1317
1318         cat.Articles[nextID] = &newArt
1319
1320         cats[catName] = cat
1321         if err := cc.Server.writeThreadedNews(); err != nil {
1322                 return res, err
1323         }
1324
1325         res = append(res, cc.NewReply(t))
1326         return res, err
1327 }
1328
1329 // HandleGetMsgs returns the flat news data
1330 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1331         if !authorize(cc.Account.Access, accessNewsReadArt) {
1332                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1333                 return res, err
1334         }
1335
1336         res = append(res, cc.NewReply(t, NewField(fieldData, cc.Server.FlatNews)))
1337
1338         return res, err
1339 }
1340
1341 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1342         if !authorize(cc.Account.Access, accessDownloadFile) {
1343                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1344                 return res, err
1345         }
1346
1347         fileName := t.GetField(fieldFileName).Data
1348         filePath := t.GetField(fieldFilePath).Data
1349         resumeData := t.GetField(fieldFileResumeData).Data
1350
1351         var dataOffset int64
1352         var frd FileResumeData
1353         if resumeData != nil {
1354                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1355                         return res, err
1356                 }
1357                 // TODO: handle rsrc fork offset
1358                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1359         }
1360
1361         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1362         if err != nil {
1363                 return res, err
1364         }
1365
1366         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1367         if err != nil {
1368                 return res, err
1369         }
1370
1371         xferSize := hlFile.ffo.TransferSize(0)
1372
1373         ft := cc.newFileTransfer(FileDownload, fileName, filePath, xferSize)
1374
1375         // TODO: refactor to remove this
1376         if resumeData != nil {
1377                 var frd FileResumeData
1378                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1379                         return res, err
1380                 }
1381                 ft.fileResumeData = &frd
1382         }
1383
1384         // Optional field for when a HL v1.5+ client requests file preview
1385         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1386         // The value will always be 2
1387         if t.GetField(fieldFileTransferOptions).Data != nil {
1388                 ft.options = t.GetField(fieldFileTransferOptions).Data
1389                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1390         }
1391
1392         res = append(res, cc.NewReply(t,
1393                 NewField(fieldRefNum, ft.refNum[:]),
1394                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1395                 NewField(fieldTransferSize, xferSize),
1396                 NewField(fieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1397         ))
1398
1399         return res, err
1400 }
1401
1402 // Download all files from the specified folder and sub-folders
1403 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1404         if !authorize(cc.Account.Access, accessDownloadFile) {
1405                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1406                 return res, err
1407         }
1408
1409         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
1410         if err != nil {
1411                 return res, err
1412         }
1413
1414         transferSize, err := CalcTotalSize(fullFilePath)
1415         if err != nil {
1416                 return res, err
1417         }
1418         itemCount, err := CalcItemCount(fullFilePath)
1419         if err != nil {
1420                 return res, err
1421         }
1422
1423         fileTransfer := cc.newFileTransfer(FolderDownload, t.GetField(fieldFileName).Data, t.GetField(fieldFilePath).Data, transferSize)
1424
1425         var fp FilePath
1426         err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
1427         if err != nil {
1428                 return res, err
1429         }
1430
1431         res = append(res, cc.NewReply(t,
1432                 NewField(fieldRefNum, fileTransfer.ReferenceNumber),
1433                 NewField(fieldTransferSize, transferSize),
1434                 NewField(fieldFolderItemCount, itemCount),
1435                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1436         ))
1437         return res, err
1438 }
1439
1440 // Upload all files from the local folder and its subfolders to the specified path on the server
1441 // Fields used in the request
1442 // 201  File name
1443 // 202  File path
1444 // 108  transfer size   Total size of all items in the folder
1445 // 220  Folder item count
1446 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1447 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1448         var fp FilePath
1449         if t.GetField(fieldFilePath).Data != nil {
1450                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1451                         return res, err
1452                 }
1453         }
1454
1455         // Handle special cases for Upload and Drop Box folders
1456         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1457                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1458                         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))))
1459                         return res, err
1460                 }
1461         }
1462
1463         fileTransfer := cc.newFileTransfer(FolderUpload,
1464                 t.GetField(fieldFileName).Data,
1465                 t.GetField(fieldFilePath).Data,
1466                 t.GetField(fieldTransferSize).Data,
1467         )
1468
1469         fileTransfer.FolderItemCount = t.GetField(fieldFolderItemCount).Data
1470
1471         res = append(res, cc.NewReply(t, NewField(fieldRefNum, fileTransfer.ReferenceNumber)))
1472         return res, err
1473 }
1474
1475 // HandleUploadFile
1476 // Fields used in the request:
1477 // 201  File name
1478 // 202  File path
1479 // 204  File transfer options   "Optional
1480 // Used only to resume download, currently has value 2"
1481 // 108  File transfer size      "Optional used if download is not resumed"
1482 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1483         if !authorize(cc.Account.Access, accessUploadFile) {
1484                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1485                 return res, err
1486         }
1487
1488         fileName := t.GetField(fieldFileName).Data
1489         filePath := t.GetField(fieldFilePath).Data
1490         transferOptions := t.GetField(fieldFileTransferOptions).Data
1491         transferSize := t.GetField(fieldTransferSize).Data // not sent for resume
1492
1493         var fp FilePath
1494         if filePath != nil {
1495                 if err = fp.UnmarshalBinary(filePath); err != nil {
1496                         return res, err
1497                 }
1498         }
1499
1500         // Handle special cases for Upload and Drop Box folders
1501         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1502                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1503                         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))))
1504                         return res, err
1505                 }
1506         }
1507         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1508         if err != nil {
1509                 return res, err
1510         }
1511
1512         if _, err := cc.Server.FS.Stat(fullFilePath); err == nil {
1513                 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))))
1514                 return res, err
1515         }
1516
1517         ft := cc.newFileTransfer(FileUpload, fileName, filePath, transferSize)
1518
1519         replyT := cc.NewReply(t, NewField(fieldRefNum, ft.ReferenceNumber))
1520
1521         // client has requested to resume a partially transferred file
1522         if transferOptions != nil {
1523
1524                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1525                 if err != nil {
1526                         return res, err
1527                 }
1528
1529                 offset := make([]byte, 4)
1530                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1531
1532                 fileResumeData := NewFileResumeData([]ForkInfoList{
1533                         *NewForkInfoList(offset),
1534                 })
1535
1536                 b, _ := fileResumeData.BinaryMarshal()
1537
1538                 ft.TransferSize = offset
1539
1540                 replyT.Fields = append(replyT.Fields, NewField(fieldFileResumeData, b))
1541         }
1542
1543         res = append(res, replyT)
1544         return res, err
1545 }
1546
1547 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1548         var icon []byte
1549         if len(t.GetField(fieldUserIconID).Data) == 4 {
1550                 icon = t.GetField(fieldUserIconID).Data[2:]
1551         } else {
1552                 icon = t.GetField(fieldUserIconID).Data
1553         }
1554         *cc.Icon = icon
1555         cc.UserName = t.GetField(fieldUserName).Data
1556
1557         // the options field is only passed by the client versions > 1.2.3.
1558         options := t.GetField(fieldOptions).Data
1559
1560         if options != nil {
1561                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1562                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
1563
1564                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, optBitmap.Bit(refusePM))
1565                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1566
1567                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, optBitmap.Bit(refuseChat))
1568                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1569
1570                 // Check auto response
1571                 if optBitmap.Bit(autoResponse) == 1 {
1572                         cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
1573                 } else {
1574                         cc.AutoReply = []byte{}
1575                 }
1576         }
1577
1578         // Notify all clients of updated user info
1579         cc.sendAll(
1580                 tranNotifyChangeUser,
1581                 NewField(fieldUserID, *cc.ID),
1582                 NewField(fieldUserIconID, *cc.Icon),
1583                 NewField(fieldUserFlags, *cc.Flags),
1584                 NewField(fieldUserName, cc.UserName),
1585         )
1586
1587         return res, err
1588 }
1589
1590 // HandleKeepAlive responds to keepalive transactions with an empty reply
1591 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1592 // * HL 1.2.3 Client doesn't send keepalives
1593 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1594         res = append(res, cc.NewReply(t))
1595
1596         return res, err
1597 }
1598
1599 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1600         fullPath, err := readPath(
1601                 cc.Server.Config.FileRoot,
1602                 t.GetField(fieldFilePath).Data,
1603                 nil,
1604         )
1605         if err != nil {
1606                 return res, err
1607         }
1608
1609         var fp FilePath
1610         if t.GetField(fieldFilePath).Data != nil {
1611                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1612                         return res, err
1613                 }
1614         }
1615
1616         // Handle special case for drop box folders
1617         if fp.IsDropbox() && !authorize(cc.Account.Access, accessViewDropBoxes) {
1618                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1619                 return res, err
1620         }
1621
1622         fileNames, err := getFileNameList(fullPath)
1623         if err != nil {
1624                 return res, err
1625         }
1626
1627         res = append(res, cc.NewReply(t, fileNames...))
1628
1629         return res, err
1630 }
1631
1632 // =================================
1633 //     Hotline private chat flow
1634 // =================================
1635 // 1. ClientA sends tranInviteNewChat to server with user ID to invite
1636 // 2. Server creates new ChatID
1637 // 3. Server sends tranInviteToChat to invitee
1638 // 4. Server replies to ClientA with new Chat ID
1639 //
1640 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1641 // If Accepted is clicked:
1642 // 1. ClientB sends tranJoinChat with fieldChatID
1643
1644 // HandleInviteNewChat invites users to new private chat
1645 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1646         if !authorize(cc.Account.Access, accessOpenChat) {
1647                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1648                 return res, err
1649         }
1650
1651         // Client to Invite
1652         targetID := t.GetField(fieldUserID).Data
1653         newChatID := cc.Server.NewPrivateChat(cc)
1654
1655         res = append(res,
1656                 *NewTransaction(
1657                         tranInviteToChat,
1658                         &targetID,
1659                         NewField(fieldChatID, newChatID),
1660                         NewField(fieldUserName, cc.UserName),
1661                         NewField(fieldUserID, *cc.ID),
1662                 ),
1663         )
1664
1665         res = append(res,
1666                 cc.NewReply(t,
1667                         NewField(fieldChatID, newChatID),
1668                         NewField(fieldUserName, cc.UserName),
1669                         NewField(fieldUserID, *cc.ID),
1670                         NewField(fieldUserIconID, *cc.Icon),
1671                         NewField(fieldUserFlags, *cc.Flags),
1672                 ),
1673         )
1674
1675         return res, err
1676 }
1677
1678 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1679         if !authorize(cc.Account.Access, accessOpenChat) {
1680                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1681                 return res, err
1682         }
1683
1684         // Client to Invite
1685         targetID := t.GetField(fieldUserID).Data
1686         chatID := t.GetField(fieldChatID).Data
1687
1688         res = append(res,
1689                 *NewTransaction(
1690                         tranInviteToChat,
1691                         &targetID,
1692                         NewField(fieldChatID, chatID),
1693                         NewField(fieldUserName, cc.UserName),
1694                         NewField(fieldUserID, *cc.ID),
1695                 ),
1696         )
1697         res = append(res,
1698                 cc.NewReply(
1699                         t,
1700                         NewField(fieldChatID, chatID),
1701                         NewField(fieldUserName, cc.UserName),
1702                         NewField(fieldUserID, *cc.ID),
1703                         NewField(fieldUserIconID, *cc.Icon),
1704                         NewField(fieldUserFlags, *cc.Flags),
1705                 ),
1706         )
1707
1708         return res, err
1709 }
1710
1711 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1712         chatID := t.GetField(fieldChatID).Data
1713         chatInt := binary.BigEndian.Uint32(chatID)
1714
1715         privChat := cc.Server.PrivateChats[chatInt]
1716
1717         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1718
1719         for _, c := range sortedClients(privChat.ClientConn) {
1720                 res = append(res,
1721                         *NewTransaction(
1722                                 tranChatMsg,
1723                                 c.ID,
1724                                 NewField(fieldChatID, chatID),
1725                                 NewField(fieldData, resMsg),
1726                         ),
1727                 )
1728         }
1729
1730         return res, err
1731 }
1732
1733 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1734 // Fields used in the reply:
1735 // * 115        Chat subject
1736 // * 300        User name with info (Optional)
1737 // * 300        (more user names with info)
1738 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1739         chatID := t.GetField(fieldChatID).Data
1740         chatInt := binary.BigEndian.Uint32(chatID)
1741
1742         privChat := cc.Server.PrivateChats[chatInt]
1743
1744         // Send tranNotifyChatChangeUser to current members of the chat to inform of new user
1745         for _, c := range sortedClients(privChat.ClientConn) {
1746                 res = append(res,
1747                         *NewTransaction(
1748                                 tranNotifyChatChangeUser,
1749                                 c.ID,
1750                                 NewField(fieldChatID, chatID),
1751                                 NewField(fieldUserName, cc.UserName),
1752                                 NewField(fieldUserID, *cc.ID),
1753                                 NewField(fieldUserIconID, *cc.Icon),
1754                                 NewField(fieldUserFlags, *cc.Flags),
1755                         ),
1756                 )
1757         }
1758
1759         privChat.ClientConn[cc.uint16ID()] = cc
1760
1761         replyFields := []Field{NewField(fieldChatSubject, []byte(privChat.Subject))}
1762         for _, c := range sortedClients(privChat.ClientConn) {
1763                 user := User{
1764                         ID:    *c.ID,
1765                         Icon:  *c.Icon,
1766                         Flags: *c.Flags,
1767                         Name:  string(c.UserName),
1768                 }
1769
1770                 replyFields = append(replyFields, NewField(fieldUsernameWithInfo, user.Payload()))
1771         }
1772
1773         res = append(res, cc.NewReply(t, replyFields...))
1774         return res, err
1775 }
1776
1777 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1778 // Fields used in the request:
1779 //      * 114   fieldChatID
1780 // Reply is not expected.
1781 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1782         chatID := t.GetField(fieldChatID).Data
1783         chatInt := binary.BigEndian.Uint32(chatID)
1784
1785         privChat, ok := cc.Server.PrivateChats[chatInt]
1786         if !ok {
1787                 return res, nil
1788         }
1789
1790         delete(privChat.ClientConn, cc.uint16ID())
1791
1792         // Notify members of the private chat that the user has left
1793         for _, c := range sortedClients(privChat.ClientConn) {
1794                 res = append(res,
1795                         *NewTransaction(
1796                                 tranNotifyChatDeleteUser,
1797                                 c.ID,
1798                                 NewField(fieldChatID, chatID),
1799                                 NewField(fieldUserID, *cc.ID),
1800                         ),
1801                 )
1802         }
1803
1804         return res, err
1805 }
1806
1807 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1808 // Fields used in the request:
1809 // * 114        Chat ID
1810 // * 115        Chat subject    Chat subject string
1811 // Reply is not expected.
1812 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1813         chatID := t.GetField(fieldChatID).Data
1814         chatInt := binary.BigEndian.Uint32(chatID)
1815
1816         privChat := cc.Server.PrivateChats[chatInt]
1817         privChat.Subject = string(t.GetField(fieldChatSubject).Data)
1818
1819         for _, c := range sortedClients(privChat.ClientConn) {
1820                 res = append(res,
1821                         *NewTransaction(
1822                                 tranNotifyChatSubject,
1823                                 c.ID,
1824                                 NewField(fieldChatID, chatID),
1825                                 NewField(fieldChatSubject, t.GetField(fieldChatSubject).Data),
1826                         ),
1827                 )
1828         }
1829
1830         return res, err
1831 }
1832
1833 // HandleMakeAlias makes a filer alias using the specified path.
1834 // Fields used in the request:
1835 // 201  File name
1836 // 202  File path
1837 // 212  File new path   Destination path
1838 //
1839 // Fields used in the reply:
1840 // None
1841 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1842         if !authorize(cc.Account.Access, accessMakeAlias) {
1843                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1844                 return res, err
1845         }
1846         fileName := t.GetField(fieldFileName).Data
1847         filePath := t.GetField(fieldFilePath).Data
1848         fileNewPath := t.GetField(fieldFileNewPath).Data
1849
1850         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1851         if err != nil {
1852                 return res, err
1853         }
1854
1855         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1856         if err != nil {
1857                 return res, err
1858         }
1859
1860         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1861
1862         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
1863                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
1864                 return res, nil
1865         }
1866
1867         res = append(res, cc.NewReply(t))
1868         return res, err
1869 }
1870
1871 func HandleDownloadBanner(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1872         fi, err := cc.Server.FS.Stat(filepath.Join(cc.Server.ConfigDir, cc.Server.Config.BannerFile))
1873         if err != nil {
1874                 return res, err
1875         }
1876
1877         ft := cc.newFileTransfer(bannerDownload, []byte{}, []byte{}, make([]byte, 4))
1878
1879         binary.BigEndian.PutUint32(ft.TransferSize, uint32(fi.Size()))
1880
1881         res = append(res, cc.NewReply(t,
1882                 NewField(fieldRefNum, ft.refNum[:]),
1883                 NewField(fieldTransferSize, ft.TransferSize),
1884         ))
1885
1886         return res, err
1887 }