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: HandleGetClientConnInfoText,
  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 }
 235
 236 func HandleChatSend(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 237         if !authorize(cc.Account.Access, accessSendChat) {
 238                 res = append(res, cc.NewErrReply(t, "You are not allowed to participate in chat."))
 239                 return res, err
 240         }
 241
 242         // Truncate long usernames
 243         trunc := fmt.Sprintf("%13s", cc.UserName)
 244         formattedMsg := fmt.Sprintf("\r%.14s:  %s", trunc, t.GetField(fieldData).Data)
 245
 246         // By holding the option key, Hotline chat allows users to send /me formatted messages like:
 247         // *** Halcyon does stuff
 248         // This is indicated by the presence of the optional field fieldChatOptions in the transaction payload
 249         if t.GetField(fieldChatOptions).Data != nil {
 250                 formattedMsg = fmt.Sprintf("\r*** %s %s", cc.UserName, t.GetField(fieldData).Data)
 251         }
 252
 253         chatID := t.GetField(fieldChatID).Data
 254         // a non-nil chatID indicates the message belongs to a private chat
 255         if chatID != nil {
 256                 chatInt := binary.BigEndian.Uint32(chatID)
 257                 privChat := cc.Server.PrivateChats[chatInt]
 258
 259                 clients := sortedClients(privChat.ClientConn)
 260
 261                 // send the message to all connected clients of the private chat
 262                 for _, c := range clients {
 263                         res = append(res, *NewTransaction(
 264                                 tranChatMsg,
 265                                 c.ID,
 266                                 NewField(fieldChatID, chatID),
 267                                 NewField(fieldData, []byte(formattedMsg)),
 268                         ))
 269                 }
 270                 return res, err
 271         }
 272
 273         for _, c := range sortedClients(cc.Server.Clients) {
 274                 // Filter out clients that do not have the read chat permission
 275                 if authorize(c.Account.Access, accessReadChat) {
 276                         res = append(res, *NewTransaction(tranChatMsg, c.ID, NewField(fieldData, []byte(formattedMsg))))
 277                 }
 278         }
 279
 280         return res, err
 281 }
 282
 283 // HandleSendInstantMsg sends instant message to the user on the current server.
 284 // Fields used in the request:
 285 //      103     User ID
 286 //      113     Options
 287 //              One of the following values:
 288 //              - User message (myOpt_UserMessage = 1)
 289 //              - Refuse message (myOpt_RefuseMessage = 2)
 290 //              - Refuse chat (myOpt_RefuseChat  = 3)
 291 //              - Automatic response (myOpt_AutomaticResponse = 4)"
 292 //      101     Data    Optional
 293 //      214     Quoting message Optional
 294 //
 295 // Fields used in the reply:
 296 // None
 297 func HandleSendInstantMsg(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 298         msg := t.GetField(fieldData)
 299         ID := t.GetField(fieldUserID)
 300
 301         reply := NewTransaction(
 302                 tranServerMsg,
 303                 &ID.Data,
 304                 NewField(fieldData, msg.Data),
 305                 NewField(fieldUserName, cc.UserName),
 306                 NewField(fieldUserID, *cc.ID),
 307                 NewField(fieldOptions, []byte{0, 1}),
 308         )
 309
 310         // Later versions of Hotline include the original message in the fieldQuotingMsg field so
 311         //  the receiving client can display both the received message and what it is in reply to
 312         if t.GetField(fieldQuotingMsg).Data != nil {
 313                 reply.Fields = append(reply.Fields, NewField(fieldQuotingMsg, t.GetField(fieldQuotingMsg).Data))
 314         }
 315
 316         res = append(res, *reply)
 317
 318         id, _ := byteToInt(ID.Data)
 319         otherClient, ok := cc.Server.Clients[uint16(id)]
 320         if !ok {
 321                 return res, errors.New("invalid client ID")
 322         }
 323
 324         // Respond with auto reply if other client has it enabled
 325         if len(otherClient.AutoReply) > 0 {
 326                 res = append(res,
 327                         *NewTransaction(
 328                                 tranServerMsg,
 329                                 cc.ID,
 330                                 NewField(fieldData, otherClient.AutoReply),
 331                                 NewField(fieldUserName, otherClient.UserName),
 332                                 NewField(fieldUserID, *otherClient.ID),
 333                                 NewField(fieldOptions, []byte{0, 1}),
 334                         ),
 335                 )
 336         }
 337
 338         res = append(res, cc.NewReply(t))
 339
 340         return res, err
 341 }
 342
 343 func HandleGetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 344         fileName := t.GetField(fieldFileName).Data
 345         filePath := t.GetField(fieldFilePath).Data
 346
 347         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 348         if err != nil {
 349                 return res, err
 350         }
 351
 352         fw, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 353         if err != nil {
 354                 return res, err
 355         }
 356
 357         res = append(res, cc.NewReply(t,
 358                 NewField(fieldFileName, []byte(fw.name)),
 359                 NewField(fieldFileTypeString, fw.ffo.FlatFileInformationFork.friendlyType()),
 360                 NewField(fieldFileCreatorString, fw.ffo.FlatFileInformationFork.friendlyCreator()),
 361                 NewField(fieldFileComment, fw.ffo.FlatFileInformationFork.Comment),
 362                 NewField(fieldFileType, fw.ffo.FlatFileInformationFork.TypeSignature),
 363                 NewField(fieldFileCreateDate, fw.ffo.FlatFileInformationFork.CreateDate),
 364                 NewField(fieldFileModifyDate, fw.ffo.FlatFileInformationFork.ModifyDate),
 365                 NewField(fieldFileSize, fw.totalSize()),
 366         ))
 367         return res, err
 368 }
 369
 370 // HandleSetFileInfo updates a file or folder name and/or comment from the Get Info window
 371 // Fields used in the request:
 372 // * 201        File name
 373 // * 202        File path       Optional
 374 // * 211        File new name   Optional
 375 // * 210        File comment    Optional
 376 // Fields used in the reply:    None
 377 func HandleSetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 378         fileName := t.GetField(fieldFileName).Data
 379         filePath := t.GetField(fieldFilePath).Data
 380
 381         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 382         if err != nil {
 383                 return res, err
 384         }
 385
 386         fi, err := cc.Server.FS.Stat(fullFilePath)
 387         if err != nil {
 388                 return res, err
 389         }
 390
 391         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 392         if err != nil {
 393                 return res, err
 394         }
 395         if t.GetField(fieldFileComment).Data != nil {
 396                 switch mode := fi.Mode(); {
 397                 case mode.IsDir():
 398                         if !authorize(cc.Account.Access, accessSetFolderComment) {
 399                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for folders."))
 400                                 return res, err
 401                         }
 402                 case mode.IsRegular():
 403                         if !authorize(cc.Account.Access, accessSetFileComment) {
 404                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for files."))
 405                                 return res, err
 406                         }
 407                 }
 408
 409                 if err := hlFile.ffo.FlatFileInformationFork.setComment(t.GetField(fieldFileComment).Data); err != nil {
 410                         return res, err
 411                 }
 412                 w, err := hlFile.infoForkWriter()
 413                 if err != nil {
 414                         return res, err
 415                 }
 416                 _, err = w.Write(hlFile.ffo.FlatFileInformationFork.MarshalBinary())
 417                 if err != nil {
 418                         return res, err
 419                 }
 420         }
 421
 422         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, t.GetField(fieldFileNewName).Data)
 423         if err != nil {
 424                 return nil, err
 425         }
 426
 427         fileNewName := t.GetField(fieldFileNewName).Data
 428
 429         if fileNewName != nil {
 430                 switch mode := fi.Mode(); {
 431                 case mode.IsDir():
 432                         if !authorize(cc.Account.Access, accessRenameFolder) {
 433                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename folders."))
 434                                 return res, err
 435                         }
 436                         err = os.Rename(fullFilePath, fullNewFilePath)
 437                         if os.IsNotExist(err) {
 438                                 res = append(res, cc.NewErrReply(t, "Cannot rename folder "+string(fileName)+" because it does not exist or cannot be found."))
 439                                 return res, err
 440                         }
 441                 case mode.IsRegular():
 442                         if !authorize(cc.Account.Access, accessRenameFile) {
 443                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename files."))
 444                                 return res, err
 445                         }
 446                         fileDir, err := readPath(cc.Server.Config.FileRoot, filePath, []byte{})
 447                         if err != nil {
 448                                 return nil, err
 449                         }
 450                         hlFile.name = string(fileNewName)
 451                         err = hlFile.move(fileDir)
 452                         if os.IsNotExist(err) {
 453                                 res = append(res, cc.NewErrReply(t, "Cannot rename file "+string(fileName)+" because it does not exist or cannot be found."))
 454                                 return res, err
 455                         }
 456                         if err != nil {
 457                                 panic(err)
 458                         }
 459                 }
 460         }
 461
 462         res = append(res, cc.NewReply(t))
 463         return res, err
 464 }
 465
 466 // HandleDeleteFile deletes a file or folder
 467 // Fields used in the request:
 468 // * 201        File name
 469 // * 202        File path
 470 // Fields used in the reply: none
 471 func HandleDeleteFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 472         fileName := t.GetField(fieldFileName).Data
 473         filePath := t.GetField(fieldFilePath).Data
 474
 475         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 476         if err != nil {
 477                 return res, err
 478         }
 479
 480         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 481         if err != nil {
 482                 return res, err
 483         }
 484
 485         fi, err := hlFile.dataFile()
 486         if err != nil {
 487                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+string(fileName)+" because it does not exist or cannot be found."))
 488                 return res, nil
 489         }
 490
 491         switch mode := fi.Mode(); {
 492         case mode.IsDir():
 493                 if !authorize(cc.Account.Access, accessDeleteFolder) {
 494                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete folders."))
 495                         return res, err
 496                 }
 497         case mode.IsRegular():
 498                 if !authorize(cc.Account.Access, accessDeleteFile) {
 499                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete files."))
 500                         return res, err
 501                 }
 502         }
 503
 504         if err := hlFile.delete(); err != nil {
 505                 return res, err
 506         }
 507
 508         res = append(res, cc.NewReply(t))
 509         return res, err
 510 }
 511
 512 // HandleMoveFile moves files or folders. Note: seemingly not documented
 513 func HandleMoveFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 514         fileName := string(t.GetField(fieldFileName).Data)
 515
 516         filePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
 517         if err != nil {
 518                 return res, err
 519         }
 520
 521         fileNewPath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFileNewPath).Data, nil)
 522         if err != nil {
 523                 return res, err
 524         }
 525
 526         cc.logger.Infow("Move file", "src", filePath+"/"+fileName, "dst", fileNewPath+"/"+fileName)
 527
 528         hlFile, err := newFileWrapper(cc.Server.FS, filePath, 0)
 529         if err != nil {
 530                 return res, err
 531         }
 532
 533         fi, err := hlFile.dataFile()
 534         if err != nil {
 535                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+fileName+" because it does not exist or cannot be found."))
 536                 return res, err
 537         }
 538         if err != nil {
 539                 return res, err
 540         }
 541         switch mode := fi.Mode(); {
 542         case mode.IsDir():
 543                 if !authorize(cc.Account.Access, accessMoveFolder) {
 544                         res = append(res, cc.NewErrReply(t, "You are not allowed to move folders."))
 545                         return res, err
 546                 }
 547         case mode.IsRegular():
 548                 if !authorize(cc.Account.Access, accessMoveFile) {
 549                         res = append(res, cc.NewErrReply(t, "You are not allowed to move files."))
 550                         return res, err
 551                 }
 552         }
 553         if err := hlFile.move(fileNewPath); err != nil {
 554                 return res, err
 555         }
 556         // TODO: handle other possible errors; e.g. fileWrapper delete fails due to fileWrapper permission issue
 557
 558         res = append(res, cc.NewReply(t))
 559         return res, err
 560 }
 561
 562 func HandleNewFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 563         if !authorize(cc.Account.Access, accessCreateFolder) {
 564                 res = append(res, cc.NewErrReply(t, "You are not allowed to create folders."))
 565                 return res, err
 566         }
 567         folderName := string(t.GetField(fieldFileName).Data)
 568
 569         folderName = path.Join("/", folderName)
 570
 571         var subPath string
 572
 573         // fieldFilePath is only present for nested paths
 574         if t.GetField(fieldFilePath).Data != nil {
 575                 var newFp FilePath
 576                 err := newFp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
 577                 if err != nil {
 578                         return nil, err
 579                 }
 580
 581                 for _, pathItem := range newFp.Items {
 582                         subPath = filepath.Join("/", subPath, string(pathItem.Name))
 583                 }
 584         }
 585         newFolderPath := path.Join(cc.Server.Config.FileRoot, subPath, folderName)
 586
 587         // TODO: check path and folder name lengths
 588
 589         if _, err := cc.Server.FS.Stat(newFolderPath); !os.IsNotExist(err) {
 590                 msg := fmt.Sprintf("Cannot create folder \"%s\" because there is already a file or folder with that name.", folderName)
 591                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 592         }
 593
 594         // TODO: check for disallowed characters to maintain compatibility for original client
 595
 596         if err := cc.Server.FS.Mkdir(newFolderPath, 0777); err != nil {
 597                 msg := fmt.Sprintf("Cannot create folder \"%s\" because an error occurred.", folderName)
 598                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 599         }
 600
 601         res = append(res, cc.NewReply(t))
 602         return res, err
 603 }
 604
 605 func HandleSetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 606         if !authorize(cc.Account.Access, accessModifyUser) {
 607                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 608                 return res, err
 609         }
 610
 611         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 612         userName := string(t.GetField(fieldUserName).Data)
 613
 614         newAccessLvl := t.GetField(fieldUserAccess).Data
 615
 616         account := cc.Server.Accounts[login]
 617         account.Access = &newAccessLvl
 618         account.Name = userName
 619
 620         // If the password field is cleared in the Hotline edit user UI, the SetUser transaction does
 621         // not include fieldUserPassword
 622         if t.GetField(fieldUserPassword).Data == nil {
 623                 account.Password = hashAndSalt([]byte(""))
 624         }
 625         if len(t.GetField(fieldUserPassword).Data) > 1 {
 626                 account.Password = hashAndSalt(t.GetField(fieldUserPassword).Data)
 627         }
 628
 629         out, err := yaml.Marshal(&account)
 630         if err != nil {
 631                 return res, err
 632         }
 633         if err := os.WriteFile(cc.Server.ConfigDir+"Users/"+login+".yaml", out, 0666); err != nil {
 634                 return res, err
 635         }
 636
 637         // Notify connected clients logged in as the user of the new access level
 638         for _, c := range cc.Server.Clients {
 639                 if c.Account.Login == login {
 640                         // Note: comment out these two lines to test server-side deny messages
 641                         newT := NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, newAccessLvl))
 642                         res = append(res, *newT)
 643
 644                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))
 645                         if authorize(c.Account.Access, accessDisconUser) {
 646                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 1)
 647                         } else {
 648                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 0)
 649                         }
 650                         binary.BigEndian.PutUint16(*c.Flags, uint16(flagBitmap.Int64()))
 651
 652                         c.Account.Access = account.Access
 653
 654                         cc.sendAll(
 655                                 tranNotifyChangeUser,
 656                                 NewField(fieldUserID, *c.ID),
 657                                 NewField(fieldUserFlags, *c.Flags),
 658                                 NewField(fieldUserName, c.UserName),
 659                                 NewField(fieldUserIconID, *c.Icon),
 660                         )
 661                 }
 662         }
 663
 664         res = append(res, cc.NewReply(t))
 665         return res, err
 666 }
 667
 668 func HandleGetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 669         if !authorize(cc.Account.Access, accessOpenUser) {
 670                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 671                 return res, err
 672         }
 673
 674         account := cc.Server.Accounts[string(t.GetField(fieldUserLogin).Data)]
 675         if account == nil {
 676                 res = append(res, cc.NewErrReply(t, "Account does not exist."))
 677                 return res, err
 678         }
 679
 680         res = append(res, cc.NewReply(t,
 681                 NewField(fieldUserName, []byte(account.Name)),
 682                 NewField(fieldUserLogin, negateString(t.GetField(fieldUserLogin).Data)),
 683                 NewField(fieldUserPassword, []byte(account.Password)),
 684                 NewField(fieldUserAccess, *account.Access),
 685         ))
 686         return res, err
 687 }
 688
 689 func HandleListUsers(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 690         if !authorize(cc.Account.Access, accessOpenUser) {
 691                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 692                 return res, err
 693         }
 694
 695         var userFields []Field
 696         for _, acc := range cc.Server.Accounts {
 697                 userField := acc.MarshalBinary()
 698                 userFields = append(userFields, NewField(fieldData, userField))
 699         }
 700
 701         res = append(res, cc.NewReply(t, userFields...))
 702         return res, err
 703 }
 704
 705 // HandleUpdateUser is used by the v1.5+ multi-user editor to perform account editing for multiple users at a time.
 706 // An update can be a mix of these actions:
 707 // * Create user
 708 // * Delete user
 709 // * Modify user (including renaming the account login)
 710 //
 711 // The Transaction sent by the client includes one data field per user that was modified.  This data field in turn
 712 // contains another data field encoded in its payload with a varying number of sub fields depending on which action is
 713 // performed.  This seems to be the only place in the Hotline protocol where a data field contains another data field.
 714 func HandleUpdateUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 715         for _, field := range t.Fields {
 716                 subFields, err := ReadFields(field.Data[0:2], field.Data[2:])
 717                 if err != nil {
 718                         return res, err
 719                 }
 720
 721                 if len(subFields) == 1 {
 722                         login := DecodeUserString(getField(fieldData, &subFields).Data)
 723                         cc.logger.Infow("DeleteUser", "login", login)
 724
 725                         if !authorize(cc.Account.Access, accessDeleteUser) {
 726                                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 727                                 return res, err
 728                         }
 729
 730                         if err := cc.Server.DeleteUser(login); err != nil {
 731                                 return res, err
 732                         }
 733                         continue
 734                 }
 735
 736                 login := DecodeUserString(getField(fieldUserLogin, &subFields).Data)
 737
 738                 // check if the login dataFile; if so, we know we are updating an existing user
 739                 if acc, ok := cc.Server.Accounts[login]; ok {
 740                         cc.logger.Infow("UpdateUser", "login", login)
 741
 742                         // account dataFile, so this is an update action
 743                         if !authorize(cc.Account.Access, accessModifyUser) {
 744                                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 745                                 return res, err
 746                         }
 747
 748                         if getField(fieldUserPassword, &subFields) != nil {
 749                                 newPass := getField(fieldUserPassword, &subFields).Data
 750                                 acc.Password = hashAndSalt(newPass)
 751                         } else {
 752                                 acc.Password = hashAndSalt([]byte(""))
 753                         }
 754
 755                         if getField(fieldUserAccess, &subFields) != nil {
 756                                 acc.Access = &getField(fieldUserAccess, &subFields).Data
 757                         }
 758
 759                         err = cc.Server.UpdateUser(
 760                                 DecodeUserString(getField(fieldData, &subFields).Data),
 761                                 DecodeUserString(getField(fieldUserLogin, &subFields).Data),
 762                                 string(getField(fieldUserName, &subFields).Data),
 763                                 acc.Password,
 764                                 *acc.Access,
 765                         )
 766                         if err != nil {
 767                                 return res, err
 768                         }
 769                 } else {
 770                         cc.logger.Infow("CreateUser", "login", login)
 771
 772                         if !authorize(cc.Account.Access, accessCreateUser) {
 773                                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 774                                 return res, err
 775                         }
 776
 777                         err := cc.Server.NewUser(
 778                                 login,
 779                                 string(getField(fieldUserName, &subFields).Data),
 780                                 string(getField(fieldUserPassword, &subFields).Data),
 781                                 getField(fieldUserAccess, &subFields).Data,
 782                         )
 783                         if err != nil {
 784                                 return []Transaction{}, err
 785                         }
 786                 }
 787         }
 788
 789         res = append(res, cc.NewReply(t))
 790         return res, err
 791 }
 792
 793 // HandleNewUser creates a new user account
 794 func HandleNewUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 795         if !authorize(cc.Account.Access, accessCreateUser) {
 796                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 797                 return res, err
 798         }
 799
 800         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 801
 802         // If the account already dataFile, reply with an error
 803         if _, ok := cc.Server.Accounts[login]; ok {
 804                 res = append(res, cc.NewErrReply(t, "Cannot create account "+login+" because there is already an account with that login."))
 805                 return res, err
 806         }
 807
 808         if err := cc.Server.NewUser(
 809                 login,
 810                 string(t.GetField(fieldUserName).Data),
 811                 string(t.GetField(fieldUserPassword).Data),
 812                 t.GetField(fieldUserAccess).Data,
 813         ); err != nil {
 814                 return []Transaction{}, err
 815         }
 816
 817         res = append(res, cc.NewReply(t))
 818         return res, err
 819 }
 820
 821 func HandleDeleteUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 822         if !authorize(cc.Account.Access, accessDeleteUser) {
 823                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 824                 return res, err
 825         }
 826
 827         // TODO: Handle case where account doesn't exist; e.g. delete race condition
 828         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 829
 830         if err := cc.Server.DeleteUser(login); err != nil {
 831                 return res, err
 832         }
 833
 834         res = append(res, cc.NewReply(t))
 835         return res, err
 836 }
 837
 838 // HandleUserBroadcast sends an Administrator Message to all connected clients of the server
 839 func HandleUserBroadcast(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 840         if !authorize(cc.Account.Access, accessBroadcast) {
 841                 res = append(res, cc.NewErrReply(t, "You are not allowed to send broadcast messages."))
 842                 return res, err
 843         }
 844
 845         cc.sendAll(
 846                 tranServerMsg,
 847                 NewField(fieldData, t.GetField(tranGetMsgs).Data),
 848                 NewField(fieldChatOptions, []byte{0}),
 849         )
 850
 851         res = append(res, cc.NewReply(t))
 852         return res, err
 853 }
 854
 855 func byteToInt(bytes []byte) (int, error) {
 856         switch len(bytes) {
 857         case 2:
 858                 return int(binary.BigEndian.Uint16(bytes)), nil
 859         case 4:
 860                 return int(binary.BigEndian.Uint32(bytes)), nil
 861         }
 862
 863         return 0, errors.New("unknown byte length")
 864 }
 865
 866 func HandleGetClientConnInfoText(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 867         if !authorize(cc.Account.Access, accessGetClientInfo) {
 868                 res = append(res, cc.NewErrReply(t, "You are not allowed to get client info"))
 869                 return res, err
 870         }
 871
 872         clientID, _ := byteToInt(t.GetField(fieldUserID).Data)
 873
 874         clientConn := cc.Server.Clients[uint16(clientID)]
 875         if clientConn == nil {
 876                 return res, errors.New("invalid client")
 877         }
 878
 879         // TODO: Implement non-hardcoded values
 880         template := `Nickname:   %s
 881 Name:       %s
 882 Account:    %s
 883 Address:    %s
 884
 885 -------- File Downloads ---------
 886
 887 %s
 888
 889 ------- Folder Downloads --------
 890
 891 None.
 892
 893 --------- File Uploads ----------
 894
 895 None.
 896
 897 -------- Folder Uploads ---------
 898
 899 None.
 900
 901 ------- Waiting Downloads -------
 902
 903 None.
 904
 905         `
 906
 907         activeDownloads := clientConn.Transfers[FileDownload]
 908         activeDownloadList := "None."
 909         for _, dl := range activeDownloads {
 910                 activeDownloadList += dl.String() + "\n"
 911         }
 912
 913         template = fmt.Sprintf(
 914                 template,
 915                 clientConn.UserName,
 916                 clientConn.Account.Name,
 917                 clientConn.Account.Login,
 918                 clientConn.RemoteAddr,
 919                 activeDownloadList,
 920         )
 921         template = strings.Replace(template, "\n", "\r", -1)
 922
 923         res = append(res, cc.NewReply(t,
 924                 NewField(fieldData, []byte(template)),
 925                 NewField(fieldUserName, clientConn.UserName),
 926         ))
 927         return res, err
 928 }
 929
 930 func HandleGetUserNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 931         res = append(res, cc.NewReply(t, cc.Server.connectedUsers()...))
 932
 933         return res, err
 934 }
 935
 936 func HandleTranAgreed(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 937         cc.Agreed = true
 938         cc.UserName = t.GetField(fieldUserName).Data
 939         *cc.Icon = t.GetField(fieldUserIconID).Data
 940
 941         cc.logger = cc.logger.With("name", string(cc.UserName))
 942
 943         options := t.GetField(fieldOptions).Data
 944         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 945
 946         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
 947
 948         // Check refuse private PM option
 949         if optBitmap.Bit(refusePM) == 1 {
 950                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, 1)
 951                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 952         }
 953
 954         // Check refuse private chat option
 955         if optBitmap.Bit(refuseChat) == 1 {
 956                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, 1)
 957                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 958         }
 959
 960         // Check auto response
 961         if optBitmap.Bit(autoResponse) == 1 {
 962                 cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
 963         } else {
 964                 cc.AutoReply = []byte{}
 965         }
 966
 967         cc.notifyOthers(
 968                 *NewTransaction(
 969                         tranNotifyChangeUser, nil,
 970                         NewField(fieldUserName, cc.UserName),
 971                         NewField(fieldUserID, *cc.ID),
 972                         NewField(fieldUserIconID, *cc.Icon),
 973                         NewField(fieldUserFlags, *cc.Flags),
 974                 ),
 975         )
 976
 977         res = append(res, cc.NewReply(t))
 978
 979         return res, err
 980 }
 981
 982 const defaultNewsDateFormat = "Jan02 15:04" // Jun23 20:49
 983 //  "Mon, 02 Jan 2006 15:04:05 MST"
 984
 985 const defaultNewsTemplate = `From %s (%s):
 986
 987 %s
 988
 989 __________________________________________________________`
 990
 991 // HandleTranOldPostNews updates the flat news
 992 // Fields used in this request:
 993 // 101  Data
 994 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 995         if !authorize(cc.Account.Access, accessNewsPostArt) {
 996                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
 997                 return res, err
 998         }
 999
1000         cc.Server.flatNewsMux.Lock()
1001         defer cc.Server.flatNewsMux.Unlock()
1002
1003         newsDateTemplate := defaultNewsDateFormat
1004         if cc.Server.Config.NewsDateFormat != "" {
1005                 newsDateTemplate = cc.Server.Config.NewsDateFormat
1006         }
1007
1008         newsTemplate := defaultNewsTemplate
1009         if cc.Server.Config.NewsDelimiter != "" {
1010                 newsTemplate = cc.Server.Config.NewsDelimiter
1011         }
1012
1013         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(fieldData).Data)
1014         newsPost = strings.Replace(newsPost, "\n", "\r", -1)
1015
1016         // update news in memory
1017         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
1018
1019         // update news on disk
1020         if err := ioutil.WriteFile(cc.Server.ConfigDir+"MessageBoard.txt", cc.Server.FlatNews, 0644); err != nil {
1021                 return res, err
1022         }
1023
1024         // Notify all clients of updated news
1025         cc.sendAll(
1026                 tranNewMsg,
1027                 NewField(fieldData, []byte(newsPost)),
1028         )
1029
1030         res = append(res, cc.NewReply(t))
1031         return res, err
1032 }
1033
1034 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1035         if !authorize(cc.Account.Access, accessDisconUser) {
1036                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1037                 return res, err
1038         }
1039
1040         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(fieldUserID).Data)]
1041
1042         if authorize(clientConn.Account.Access, accessCannotBeDiscon) {
1043                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1044                 return res, err
1045         }
1046
1047         if err := clientConn.Connection.Close(); err != nil {
1048                 return res, err
1049         }
1050
1051         res = append(res, cc.NewReply(t))
1052         return res, err
1053 }
1054
1055 // HandleGetNewsCatNameList returns a list of news categories for a path
1056 // Fields used in the request:
1057 // 325  News path       (Optional)
1058 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1059         if !authorize(cc.Account.Access, accessNewsReadArt) {
1060                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1061                 return res, err
1062         }
1063
1064         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1065         cats := cc.Server.GetNewsCatByPath(pathStrs)
1066
1067         // To store the keys in slice in sorted order
1068         keys := make([]string, len(cats))
1069         i := 0
1070         for k := range cats {
1071                 keys[i] = k
1072                 i++
1073         }
1074         sort.Strings(keys)
1075
1076         var fieldData []Field
1077         for _, k := range keys {
1078                 cat := cats[k]
1079                 b, _ := cat.MarshalBinary()
1080                 fieldData = append(fieldData, NewField(
1081                         fieldNewsCatListData15,
1082                         b,
1083                 ))
1084         }
1085
1086         res = append(res, cc.NewReply(t, fieldData...))
1087         return res, err
1088 }
1089
1090 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1091         if !authorize(cc.Account.Access, accessNewsCreateCat) {
1092                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1093                 return res, err
1094         }
1095
1096         name := string(t.GetField(fieldNewsCatName).Data)
1097         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1098
1099         cats := cc.Server.GetNewsCatByPath(pathStrs)
1100         cats[name] = NewsCategoryListData15{
1101                 Name:     name,
1102                 Type:     []byte{0, 3},
1103                 Articles: map[uint32]*NewsArtData{},
1104                 SubCats:  make(map[string]NewsCategoryListData15),
1105         }
1106
1107         if err := cc.Server.writeThreadedNews(); err != nil {
1108                 return res, err
1109         }
1110         res = append(res, cc.NewReply(t))
1111         return res, err
1112 }
1113
1114 // Fields used in the request:
1115 // 322  News category name
1116 // 325  News path
1117 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1118         if !authorize(cc.Account.Access, accessNewsCreateFldr) {
1119                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1120                 return res, err
1121         }
1122
1123         name := string(t.GetField(fieldFileName).Data)
1124         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1125
1126         cc.logger.Infof("Creating new news folder %s", name)
1127
1128         cats := cc.Server.GetNewsCatByPath(pathStrs)
1129         cats[name] = NewsCategoryListData15{
1130                 Name:     name,
1131                 Type:     []byte{0, 2},
1132                 Articles: map[uint32]*NewsArtData{},
1133                 SubCats:  make(map[string]NewsCategoryListData15),
1134         }
1135         if err := cc.Server.writeThreadedNews(); err != nil {
1136                 return res, err
1137         }
1138         res = append(res, cc.NewReply(t))
1139         return res, err
1140 }
1141
1142 // Fields used in the request:
1143 // 325  News path       Optional
1144 //
1145 // Reply fields:
1146 // 321  News article list data  Optional
1147 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1148         if !authorize(cc.Account.Access, accessNewsReadArt) {
1149                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1150                 return res, err
1151         }
1152         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1153
1154         var cat NewsCategoryListData15
1155         cats := cc.Server.ThreadedNews.Categories
1156
1157         for _, fp := range pathStrs {
1158                 cat = cats[fp]
1159                 cats = cats[fp].SubCats
1160         }
1161
1162         nald := cat.GetNewsArtListData()
1163
1164         res = append(res, cc.NewReply(t, NewField(fieldNewsArtListData, nald.Payload())))
1165         return res, err
1166 }
1167
1168 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1169         if !authorize(cc.Account.Access, accessNewsReadArt) {
1170                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1171                 return res, err
1172         }
1173
1174         // Request fields
1175         // 325  News fp
1176         // 326  News article ID
1177         // 327  News article data flavor
1178
1179         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1180
1181         var cat NewsCategoryListData15
1182         cats := cc.Server.ThreadedNews.Categories
1183
1184         for _, fp := range pathStrs {
1185                 cat = cats[fp]
1186                 cats = cats[fp].SubCats
1187         }
1188         newsArtID := t.GetField(fieldNewsArtID).Data
1189
1190         convertedArtID := binary.BigEndian.Uint16(newsArtID)
1191
1192         art := cat.Articles[uint32(convertedArtID)]
1193         if art == nil {
1194                 res = append(res, cc.NewReply(t))
1195                 return res, err
1196         }
1197
1198         // Reply fields
1199         // 328  News article title
1200         // 329  News article poster
1201         // 330  News article date
1202         // 331  Previous article ID
1203         // 332  Next article ID
1204         // 335  Parent article ID
1205         // 336  First child article ID
1206         // 327  News article data flavor        "Should be “text/plain”
1207         // 333  News article data       Optional (if data flavor is “text/plain”)
1208
1209         res = append(res, cc.NewReply(t,
1210                 NewField(fieldNewsArtTitle, []byte(art.Title)),
1211                 NewField(fieldNewsArtPoster, []byte(art.Poster)),
1212                 NewField(fieldNewsArtDate, art.Date),
1213                 NewField(fieldNewsArtPrevArt, art.PrevArt),
1214                 NewField(fieldNewsArtNextArt, art.NextArt),
1215                 NewField(fieldNewsArtParentArt, art.ParentArt),
1216                 NewField(fieldNewsArt1stChildArt, art.FirstChildArt),
1217                 NewField(fieldNewsArtDataFlav, []byte("text/plain")),
1218                 NewField(fieldNewsArtData, []byte(art.Data)),
1219         ))
1220         return res, err
1221 }
1222
1223 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1224         // Has multiple access flags: News Delete Folder (37) or News Delete Category (35)
1225         // TODO: Implement
1226
1227         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1228
1229         // TODO: determine if path is a Folder (Bundle) or Category and check for permission
1230
1231         cc.logger.Infof("DelNewsItem %v", pathStrs)
1232
1233         cats := cc.Server.ThreadedNews.Categories
1234
1235         delName := pathStrs[len(pathStrs)-1]
1236         if len(pathStrs) > 1 {
1237                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1238                         cats = cats[fp].SubCats
1239                 }
1240         }
1241
1242         delete(cats, delName)
1243
1244         err = cc.Server.writeThreadedNews()
1245         if err != nil {
1246                 return res, err
1247         }
1248
1249         // Reply params: none
1250         res = append(res, cc.NewReply(t))
1251
1252         return res, err
1253 }
1254
1255 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1256         if !authorize(cc.Account.Access, accessNewsDeleteArt) {
1257                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1258                 return res, err
1259         }
1260
1261         // Request Fields
1262         // 325  News path
1263         // 326  News article ID
1264         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1265         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1266         ID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1267
1268         // TODO: Delete recursive
1269         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1270
1271         catName := pathStrs[len(pathStrs)-1]
1272         cat := cats[catName]
1273
1274         delete(cat.Articles, uint32(ID))
1275
1276         cats[catName] = cat
1277         if err := cc.Server.writeThreadedNews(); err != nil {
1278                 return res, err
1279         }
1280
1281         res = append(res, cc.NewReply(t))
1282         return res, err
1283 }
1284
1285 // Request fields
1286 // 325  News path
1287 // 326  News article ID                                                 ID of the parent article?
1288 // 328  News article title
1289 // 334  News article flags
1290 // 327  News article data flavor                Currently “text/plain”
1291 // 333  News article data
1292 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1293         if !authorize(cc.Account.Access, accessNewsPostArt) {
1294                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1295                 return res, err
1296         }
1297
1298         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1299         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1300
1301         catName := pathStrs[len(pathStrs)-1]
1302         cat := cats[catName]
1303
1304         newArt := NewsArtData{
1305                 Title:         string(t.GetField(fieldNewsArtTitle).Data),
1306                 Poster:        string(cc.UserName),
1307                 Date:          toHotlineTime(time.Now()),
1308                 PrevArt:       []byte{0, 0, 0, 0},
1309                 NextArt:       []byte{0, 0, 0, 0},
1310                 ParentArt:     append([]byte{0, 0}, t.GetField(fieldNewsArtID).Data...),
1311                 FirstChildArt: []byte{0, 0, 0, 0},
1312                 DataFlav:      []byte("text/plain"),
1313                 Data:          string(t.GetField(fieldNewsArtData).Data),
1314         }
1315
1316         var keys []int
1317         for k := range cat.Articles {
1318                 keys = append(keys, int(k))
1319         }
1320
1321         nextID := uint32(1)
1322         if len(keys) > 0 {
1323                 sort.Ints(keys)
1324                 prevID := uint32(keys[len(keys)-1])
1325                 nextID = prevID + 1
1326
1327                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1328
1329                 // Set next article ID
1330                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1331         }
1332
1333         // Update parent article with first child reply
1334         parentID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1335         if parentID != 0 {
1336                 parentArt := cat.Articles[uint32(parentID)]
1337
1338                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1339                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1340                 }
1341         }
1342
1343         cat.Articles[nextID] = &newArt
1344
1345         cats[catName] = cat
1346         if err := cc.Server.writeThreadedNews(); err != nil {
1347                 return res, err
1348         }
1349
1350         res = append(res, cc.NewReply(t))
1351         return res, err
1352 }
1353
1354 // HandleGetMsgs returns the flat news data
1355 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1356         if !authorize(cc.Account.Access, accessNewsReadArt) {
1357                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1358                 return res, err
1359         }
1360
1361         res = append(res, cc.NewReply(t, NewField(fieldData, cc.Server.FlatNews)))
1362
1363         return res, err
1364 }
1365
1366 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1367         if !authorize(cc.Account.Access, accessDownloadFile) {
1368                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1369                 return res, err
1370         }
1371
1372         fileName := t.GetField(fieldFileName).Data
1373         filePath := t.GetField(fieldFilePath).Data
1374         resumeData := t.GetField(fieldFileResumeData).Data
1375
1376         var dataOffset int64
1377         var frd FileResumeData
1378         if resumeData != nil {
1379                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1380                         return res, err
1381                 }
1382                 // TODO: handle rsrc fork offset
1383                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1384         }
1385
1386         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1387         if err != nil {
1388                 return res, err
1389         }
1390
1391         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1392         if err != nil {
1393                 return res, err
1394         }
1395
1396         transactionRef := cc.Server.NewTransactionRef()
1397         data := binary.BigEndian.Uint32(transactionRef)
1398
1399         ft := &FileTransfer{
1400                 FileName:        fileName,
1401                 FilePath:        filePath,
1402                 ReferenceNumber: transactionRef,
1403                 Type:            FileDownload,
1404         }
1405
1406         // TODO: refactor to remove this
1407         if resumeData != nil {
1408                 var frd FileResumeData
1409                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1410                         return res, err
1411                 }
1412                 ft.fileResumeData = &frd
1413         }
1414
1415         xferSize := hlFile.ffo.TransferSize(0)
1416
1417         // Optional field for when a HL v1.5+ client requests file preview
1418         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1419         // The value will always be 2
1420         if t.GetField(fieldFileTransferOptions).Data != nil {
1421                 ft.options = t.GetField(fieldFileTransferOptions).Data
1422                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1423         }
1424
1425         cc.Server.mux.Lock()
1426         defer cc.Server.mux.Unlock()
1427         cc.Server.FileTransfers[data] = ft
1428
1429         cc.Transfers[FileDownload] = append(cc.Transfers[FileDownload], ft)
1430
1431         res = append(res, cc.NewReply(t,
1432                 NewField(fieldRefNum, transactionRef),
1433                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1434                 NewField(fieldTransferSize, xferSize),
1435                 NewField(fieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1436         ))
1437
1438         return res, err
1439 }
1440
1441 // Download all files from the specified folder and sub-folders
1442 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1443         if !authorize(cc.Account.Access, accessDownloadFile) {
1444                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1445                 return res, err
1446         }
1447
1448         transactionRef := cc.Server.NewTransactionRef()
1449         data := binary.BigEndian.Uint32(transactionRef)
1450
1451         fileTransfer := &FileTransfer{
1452                 FileName:        t.GetField(fieldFileName).Data,
1453                 FilePath:        t.GetField(fieldFilePath).Data,
1454                 ReferenceNumber: transactionRef,
1455                 Type:            FolderDownload,
1456         }
1457         cc.Server.mux.Lock()
1458         cc.Server.FileTransfers[data] = fileTransfer
1459         cc.Server.mux.Unlock()
1460         cc.Transfers[FolderDownload] = append(cc.Transfers[FolderDownload], fileTransfer)
1461
1462         var fp FilePath
1463         err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
1464         if err != nil {
1465                 return res, err
1466         }
1467
1468         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
1469         if err != nil {
1470                 return res, err
1471         }
1472
1473         transferSize, err := CalcTotalSize(fullFilePath)
1474         if err != nil {
1475                 return res, err
1476         }
1477         itemCount, err := CalcItemCount(fullFilePath)
1478         if err != nil {
1479                 return res, err
1480         }
1481         res = append(res, cc.NewReply(t,
1482                 NewField(fieldRefNum, transactionRef),
1483                 NewField(fieldTransferSize, transferSize),
1484                 NewField(fieldFolderItemCount, itemCount),
1485                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1486         ))
1487         return res, err
1488 }
1489
1490 // Upload all files from the local folder and its subfolders to the specified path on the server
1491 // Fields used in the request
1492 // 201  File name
1493 // 202  File path
1494 // 108  transfer size   Total size of all items in the folder
1495 // 220  Folder item count
1496 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1497 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1498         transactionRef := cc.Server.NewTransactionRef()
1499         data := binary.BigEndian.Uint32(transactionRef)
1500
1501         var fp FilePath
1502         if t.GetField(fieldFilePath).Data != nil {
1503                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1504                         return res, err
1505                 }
1506         }
1507
1508         // Handle special cases for Upload and Drop Box folders
1509         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1510                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1511                         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))))
1512                         return res, err
1513                 }
1514         }
1515
1516         fileTransfer := &FileTransfer{
1517                 FileName:        t.GetField(fieldFileName).Data,
1518                 FilePath:        t.GetField(fieldFilePath).Data,
1519                 ReferenceNumber: transactionRef,
1520                 Type:            FolderUpload,
1521                 FolderItemCount: t.GetField(fieldFolderItemCount).Data,
1522                 TransferSize:    t.GetField(fieldTransferSize).Data,
1523         }
1524         cc.Server.FileTransfers[data] = fileTransfer
1525
1526         res = append(res, cc.NewReply(t, NewField(fieldRefNum, transactionRef)))
1527         return res, err
1528 }
1529
1530 // HandleUploadFile
1531 // Fields used in the request:
1532 // 201  File name
1533 // 202  File path
1534 // 204  File transfer options   "Optional
1535 // Used only to resume download, currently has value 2"
1536 // 108  File transfer size      "Optional used if download is not resumed"
1537 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1538         if !authorize(cc.Account.Access, accessUploadFile) {
1539                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1540                 return res, err
1541         }
1542
1543         fileName := t.GetField(fieldFileName).Data
1544         filePath := t.GetField(fieldFilePath).Data
1545
1546         transferOptions := t.GetField(fieldFileTransferOptions).Data
1547
1548         // TODO: is this field useful for anything?
1549         // transferSize := t.GetField(fieldTransferSize).Data
1550
1551         var fp FilePath
1552         if filePath != nil {
1553                 if err = fp.UnmarshalBinary(filePath); err != nil {
1554                         return res, err
1555                 }
1556         }
1557
1558         // Handle special cases for Upload and Drop Box folders
1559         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1560                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1561                         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))))
1562                         return res, err
1563                 }
1564         }
1565
1566         transactionRef := cc.Server.NewTransactionRef()
1567         data := binary.BigEndian.Uint32(transactionRef)
1568
1569         cc.Server.mux.Lock()
1570         cc.Server.FileTransfers[data] = &FileTransfer{
1571                 FileName:        fileName,
1572                 FilePath:        filePath,
1573                 ReferenceNumber: transactionRef,
1574                 Type:            FileUpload,
1575         }
1576         cc.Server.mux.Unlock()
1577
1578         replyT := cc.NewReply(t, NewField(fieldRefNum, transactionRef))
1579
1580         // client has requested to resume a partially transferred file
1581         if transferOptions != nil {
1582                 fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1583                 if err != nil {
1584                         return res, err
1585                 }
1586
1587                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1588                 if err != nil {
1589                         return res, err
1590                 }
1591
1592                 offset := make([]byte, 4)
1593                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1594
1595                 fileResumeData := NewFileResumeData([]ForkInfoList{
1596                         *NewForkInfoList(offset),
1597                 })
1598
1599                 b, _ := fileResumeData.BinaryMarshal()
1600
1601                 replyT.Fields = append(replyT.Fields, NewField(fieldFileResumeData, b))
1602         }
1603
1604         res = append(res, replyT)
1605         return res, err
1606 }
1607
1608 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1609         var icon []byte
1610         if len(t.GetField(fieldUserIconID).Data) == 4 {
1611                 icon = t.GetField(fieldUserIconID).Data[2:]
1612         } else {
1613                 icon = t.GetField(fieldUserIconID).Data
1614         }
1615         *cc.Icon = icon
1616         cc.UserName = t.GetField(fieldUserName).Data
1617
1618         // the options field is only passed by the client versions > 1.2.3.
1619         options := t.GetField(fieldOptions).Data
1620
1621         if options != nil {
1622                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1623                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
1624
1625                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, optBitmap.Bit(refusePM))
1626                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1627
1628                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, optBitmap.Bit(refuseChat))
1629                 binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
1630
1631                 // Check auto response
1632                 if optBitmap.Bit(autoResponse) == 1 {
1633                         cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
1634                 } else {
1635                         cc.AutoReply = []byte{}
1636                 }
1637         }
1638
1639         // Notify all clients of updated user info
1640         cc.sendAll(
1641                 tranNotifyChangeUser,
1642                 NewField(fieldUserID, *cc.ID),
1643                 NewField(fieldUserIconID, *cc.Icon),
1644                 NewField(fieldUserFlags, *cc.Flags),
1645                 NewField(fieldUserName, cc.UserName),
1646         )
1647
1648         return res, err
1649 }
1650
1651 // HandleKeepAlive responds to keepalive transactions with an empty reply
1652 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1653 // * HL 1.2.3 Client doesn't send keepalives
1654 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1655         res = append(res, cc.NewReply(t))
1656
1657         return res, err
1658 }
1659
1660 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1661         fullPath, err := readPath(
1662                 cc.Server.Config.FileRoot,
1663                 t.GetField(fieldFilePath).Data,
1664                 nil,
1665         )
1666         if err != nil {
1667                 return res, err
1668         }
1669
1670         var fp FilePath
1671         if t.GetField(fieldFilePath).Data != nil {
1672                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1673                         return res, err
1674                 }
1675         }
1676
1677         // Handle special case for drop box folders
1678         if fp.IsDropbox() && !authorize(cc.Account.Access, accessViewDropBoxes) {
1679                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1680                 return res, err
1681         }
1682
1683         fileNames, err := getFileNameList(fullPath)
1684         if err != nil {
1685                 return res, err
1686         }
1687
1688         res = append(res, cc.NewReply(t, fileNames...))
1689
1690         return res, err
1691 }
1692
1693 // =================================
1694 //     Hotline private chat flow
1695 // =================================
1696 // 1. ClientA sends tranInviteNewChat to server with user ID to invite
1697 // 2. Server creates new ChatID
1698 // 3. Server sends tranInviteToChat to invitee
1699 // 4. Server replies to ClientA with new Chat ID
1700 //
1701 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1702 // If Accepted is clicked:
1703 // 1. ClientB sends tranJoinChat with fieldChatID
1704
1705 // HandleInviteNewChat invites users to new private chat
1706 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1707         if !authorize(cc.Account.Access, accessOpenChat) {
1708                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1709                 return res, err
1710         }
1711
1712         // Client to Invite
1713         targetID := t.GetField(fieldUserID).Data
1714         newChatID := cc.Server.NewPrivateChat(cc)
1715
1716         res = append(res,
1717                 *NewTransaction(
1718                         tranInviteToChat,
1719                         &targetID,
1720                         NewField(fieldChatID, newChatID),
1721                         NewField(fieldUserName, cc.UserName),
1722                         NewField(fieldUserID, *cc.ID),
1723                 ),
1724         )
1725
1726         res = append(res,
1727                 cc.NewReply(t,
1728                         NewField(fieldChatID, newChatID),
1729                         NewField(fieldUserName, cc.UserName),
1730                         NewField(fieldUserID, *cc.ID),
1731                         NewField(fieldUserIconID, *cc.Icon),
1732                         NewField(fieldUserFlags, *cc.Flags),
1733                 ),
1734         )
1735
1736         return res, err
1737 }
1738
1739 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1740         if !authorize(cc.Account.Access, accessOpenChat) {
1741                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1742                 return res, err
1743         }
1744
1745         // Client to Invite
1746         targetID := t.GetField(fieldUserID).Data
1747         chatID := t.GetField(fieldChatID).Data
1748
1749         res = append(res,
1750                 *NewTransaction(
1751                         tranInviteToChat,
1752                         &targetID,
1753                         NewField(fieldChatID, chatID),
1754                         NewField(fieldUserName, cc.UserName),
1755                         NewField(fieldUserID, *cc.ID),
1756                 ),
1757         )
1758         res = append(res,
1759                 cc.NewReply(
1760                         t,
1761                         NewField(fieldChatID, chatID),
1762                         NewField(fieldUserName, cc.UserName),
1763                         NewField(fieldUserID, *cc.ID),
1764                         NewField(fieldUserIconID, *cc.Icon),
1765                         NewField(fieldUserFlags, *cc.Flags),
1766                 ),
1767         )
1768
1769         return res, err
1770 }
1771
1772 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1773         chatID := t.GetField(fieldChatID).Data
1774         chatInt := binary.BigEndian.Uint32(chatID)
1775
1776         privChat := cc.Server.PrivateChats[chatInt]
1777
1778         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1779
1780         for _, c := range sortedClients(privChat.ClientConn) {
1781                 res = append(res,
1782                         *NewTransaction(
1783                                 tranChatMsg,
1784                                 c.ID,
1785                                 NewField(fieldChatID, chatID),
1786                                 NewField(fieldData, resMsg),
1787                         ),
1788                 )
1789         }
1790
1791         return res, err
1792 }
1793
1794 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1795 // Fields used in the reply:
1796 // * 115        Chat subject
1797 // * 300        User name with info (Optional)
1798 // * 300        (more user names with info)
1799 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1800         chatID := t.GetField(fieldChatID).Data
1801         chatInt := binary.BigEndian.Uint32(chatID)
1802
1803         privChat := cc.Server.PrivateChats[chatInt]
1804
1805         // Send tranNotifyChatChangeUser to current members of the chat to inform of new user
1806         for _, c := range sortedClients(privChat.ClientConn) {
1807                 res = append(res,
1808                         *NewTransaction(
1809                                 tranNotifyChatChangeUser,
1810                                 c.ID,
1811                                 NewField(fieldChatID, chatID),
1812                                 NewField(fieldUserName, cc.UserName),
1813                                 NewField(fieldUserID, *cc.ID),
1814                                 NewField(fieldUserIconID, *cc.Icon),
1815                                 NewField(fieldUserFlags, *cc.Flags),
1816                         ),
1817                 )
1818         }
1819
1820         privChat.ClientConn[cc.uint16ID()] = cc
1821
1822         replyFields := []Field{NewField(fieldChatSubject, []byte(privChat.Subject))}
1823         for _, c := range sortedClients(privChat.ClientConn) {
1824                 user := User{
1825                         ID:    *c.ID,
1826                         Icon:  *c.Icon,
1827                         Flags: *c.Flags,
1828                         Name:  string(c.UserName),
1829                 }
1830
1831                 replyFields = append(replyFields, NewField(fieldUsernameWithInfo, user.Payload()))
1832         }
1833
1834         res = append(res, cc.NewReply(t, replyFields...))
1835         return res, err
1836 }
1837
1838 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1839 // Fields used in the request:
1840 //      * 114   fieldChatID
1841 // Reply is not expected.
1842 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1843         chatID := t.GetField(fieldChatID).Data
1844         chatInt := binary.BigEndian.Uint32(chatID)
1845
1846         privChat := cc.Server.PrivateChats[chatInt]
1847
1848         delete(privChat.ClientConn, cc.uint16ID())
1849
1850         // Notify members of the private chat that the user has left
1851         for _, c := range sortedClients(privChat.ClientConn) {
1852                 res = append(res,
1853                         *NewTransaction(
1854                                 tranNotifyChatDeleteUser,
1855                                 c.ID,
1856                                 NewField(fieldChatID, chatID),
1857                                 NewField(fieldUserID, *cc.ID),
1858                         ),
1859                 )
1860         }
1861
1862         return res, err
1863 }
1864
1865 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1866 // Fields used in the request:
1867 // * 114        Chat ID
1868 // * 115        Chat subject    Chat subject string
1869 // Reply is not expected.
1870 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1871         chatID := t.GetField(fieldChatID).Data
1872         chatInt := binary.BigEndian.Uint32(chatID)
1873
1874         privChat := cc.Server.PrivateChats[chatInt]
1875         privChat.Subject = string(t.GetField(fieldChatSubject).Data)
1876
1877         for _, c := range sortedClients(privChat.ClientConn) {
1878                 res = append(res,
1879                         *NewTransaction(
1880                                 tranNotifyChatSubject,
1881                                 c.ID,
1882                                 NewField(fieldChatID, chatID),
1883                                 NewField(fieldChatSubject, t.GetField(fieldChatSubject).Data),
1884                         ),
1885                 )
1886         }
1887
1888         return res, err
1889 }
1890
1891 // HandleMakeAlias makes a filer alias using the specified path.
1892 // Fields used in the request:
1893 // 201  File name
1894 // 202  File path
1895 // 212  File new path   Destination path
1896 //
1897 // Fields used in the reply:
1898 // None
1899 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1900         if !authorize(cc.Account.Access, accessMakeAlias) {
1901                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1902                 return res, err
1903         }
1904         fileName := t.GetField(fieldFileName).Data
1905         filePath := t.GetField(fieldFilePath).Data
1906         fileNewPath := t.GetField(fieldFileNewPath).Data
1907
1908         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1909         if err != nil {
1910                 return res, err
1911         }
1912
1913         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1914         if err != nil {
1915                 return res, err
1916         }
1917
1918         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1919
1920         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
1921                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
1922                 return res, nil
1923         }
1924
1925         res = append(res, cc.NewReply(t))
1926         return res, err
1927 }