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         "math/big"
  10         "os"
  11         "path"
  12         "path/filepath"
  13         "sort"
  14         "strings"
  15         "time"
  16 )
  17
  18 type HandlerFunc func(*ClientConn, *Transaction) ([]Transaction, error)
  19
  20 type TransactionType struct {
  21         Handler        HandlerFunc // function for handling the transaction type
  22         Name           string      // Name of transaction as it will appear in logging
  23         RequiredFields []requiredField
  24 }
  25
  26 var TransactionHandlers = map[uint16]TransactionType{
  27         // Server initiated
  28         TranChatMsg: {
  29                 Name: "TranChatMsg",
  30         },
  31         // Server initiated
  32         TranNotifyChangeUser: {
  33                 Name: "TranNotifyChangeUser",
  34         },
  35         TranError: {
  36                 Name: "TranError",
  37         },
  38         TranShowAgreement: {
  39                 Name: "TranShowAgreement",
  40         },
  41         TranUserAccess: {
  42                 Name: "TranUserAccess",
  43         },
  44         TranNotifyDeleteUser: {
  45                 Name: "TranNotifyDeleteUser",
  46         },
  47         TranAgreed: {
  48                 Name:    "TranAgreed",
  49                 Handler: HandleTranAgreed,
  50         },
  51         TranChatSend: {
  52                 Name:    "TranChatSend",
  53                 Handler: HandleChatSend,
  54                 RequiredFields: []requiredField{
  55                         {
  56                                 ID:     FieldData,
  57                                 minLen: 0,
  58                         },
  59                 },
  60         },
  61         TranDelNewsArt: {
  62                 Name:    "TranDelNewsArt",
  63                 Handler: HandleDelNewsArt,
  64         },
  65         TranDelNewsItem: {
  66                 Name:    "TranDelNewsItem",
  67                 Handler: HandleDelNewsItem,
  68         },
  69         TranDeleteFile: {
  70                 Name:    "TranDeleteFile",
  71                 Handler: HandleDeleteFile,
  72         },
  73         TranDeleteUser: {
  74                 Name:    "TranDeleteUser",
  75                 Handler: HandleDeleteUser,
  76         },
  77         TranDisconnectUser: {
  78                 Name:    "TranDisconnectUser",
  79                 Handler: HandleDisconnectUser,
  80         },
  81         TranDownloadFile: {
  82                 Name:    "TranDownloadFile",
  83                 Handler: HandleDownloadFile,
  84         },
  85         TranDownloadFldr: {
  86                 Name:    "TranDownloadFldr",
  87                 Handler: HandleDownloadFolder,
  88         },
  89         TranGetClientInfoText: {
  90                 Name:    "TranGetClientInfoText",
  91                 Handler: HandleGetClientInfoText,
  92         },
  93         TranGetFileInfo: {
  94                 Name:    "TranGetFileInfo",
  95                 Handler: HandleGetFileInfo,
  96         },
  97         TranGetFileNameList: {
  98                 Name:    "TranGetFileNameList",
  99                 Handler: HandleGetFileNameList,
 100         },
 101         TranGetMsgs: {
 102                 Name:    "TranGetMsgs",
 103                 Handler: HandleGetMsgs,
 104         },
 105         TranGetNewsArtData: {
 106                 Name:    "TranGetNewsArtData",
 107                 Handler: HandleGetNewsArtData,
 108         },
 109         TranGetNewsArtNameList: {
 110                 Name:    "TranGetNewsArtNameList",
 111                 Handler: HandleGetNewsArtNameList,
 112         },
 113         TranGetNewsCatNameList: {
 114                 Name:    "TranGetNewsCatNameList",
 115                 Handler: HandleGetNewsCatNameList,
 116         },
 117         TranGetUser: {
 118                 Name:    "TranGetUser",
 119                 Handler: HandleGetUser,
 120         },
 121         TranGetUserNameList: {
 122                 Name:    "tranHandleGetUserNameList",
 123                 Handler: HandleGetUserNameList,
 124         },
 125         TranInviteNewChat: {
 126                 Name:    "TranInviteNewChat",
 127                 Handler: HandleInviteNewChat,
 128         },
 129         TranInviteToChat: {
 130                 Name:    "TranInviteToChat",
 131                 Handler: HandleInviteToChat,
 132         },
 133         TranJoinChat: {
 134                 Name:    "TranJoinChat",
 135                 Handler: HandleJoinChat,
 136         },
 137         TranKeepAlive: {
 138                 Name:    "TranKeepAlive",
 139                 Handler: HandleKeepAlive,
 140         },
 141         TranLeaveChat: {
 142                 Name:    "TranJoinChat",
 143                 Handler: HandleLeaveChat,
 144         },
 145         TranListUsers: {
 146                 Name:    "TranListUsers",
 147                 Handler: HandleListUsers,
 148         },
 149         TranMoveFile: {
 150                 Name:    "TranMoveFile",
 151                 Handler: HandleMoveFile,
 152         },
 153         TranNewFolder: {
 154                 Name:    "TranNewFolder",
 155                 Handler: HandleNewFolder,
 156         },
 157         TranNewNewsCat: {
 158                 Name:    "TranNewNewsCat",
 159                 Handler: HandleNewNewsCat,
 160         },
 161         TranNewNewsFldr: {
 162                 Name:    "TranNewNewsFldr",
 163                 Handler: HandleNewNewsFldr,
 164         },
 165         TranNewUser: {
 166                 Name:    "TranNewUser",
 167                 Handler: HandleNewUser,
 168         },
 169         TranUpdateUser: {
 170                 Name:    "TranUpdateUser",
 171                 Handler: HandleUpdateUser,
 172         },
 173         TranOldPostNews: {
 174                 Name:    "TranOldPostNews",
 175                 Handler: HandleTranOldPostNews,
 176         },
 177         TranPostNewsArt: {
 178                 Name:    "TranPostNewsArt",
 179                 Handler: HandlePostNewsArt,
 180         },
 181         TranRejectChatInvite: {
 182                 Name:    "TranRejectChatInvite",
 183                 Handler: HandleRejectChatInvite,
 184         },
 185         TranSendInstantMsg: {
 186                 Name:    "TranSendInstantMsg",
 187                 Handler: HandleSendInstantMsg,
 188                 RequiredFields: []requiredField{
 189                         {
 190                                 ID:     FieldData,
 191                                 minLen: 0,
 192                         },
 193                         {
 194                                 ID: FieldUserID,
 195                         },
 196                 },
 197         },
 198         TranSetChatSubject: {
 199                 Name:    "TranSetChatSubject",
 200                 Handler: HandleSetChatSubject,
 201         },
 202         TranMakeFileAlias: {
 203                 Name:    "TranMakeFileAlias",
 204                 Handler: HandleMakeAlias,
 205                 RequiredFields: []requiredField{
 206                         {ID: FieldFileName, minLen: 1},
 207                         {ID: FieldFilePath, minLen: 1},
 208                         {ID: FieldFileNewPath, minLen: 1},
 209                 },
 210         },
 211         TranSetClientUserInfo: {
 212                 Name:    "TranSetClientUserInfo",
 213                 Handler: HandleSetClientUserInfo,
 214         },
 215         TranSetFileInfo: {
 216                 Name:    "TranSetFileInfo",
 217                 Handler: HandleSetFileInfo,
 218         },
 219         TranSetUser: {
 220                 Name:    "TranSetUser",
 221                 Handler: HandleSetUser,
 222         },
 223         TranUploadFile: {
 224                 Name:    "TranUploadFile",
 225                 Handler: HandleUploadFile,
 226         },
 227         TranUploadFldr: {
 228                 Name:    "TranUploadFldr",
 229                 Handler: HandleUploadFolder,
 230         },
 231         TranUserBroadcast: {
 232                 Name:    "TranUserBroadcast",
 233                 Handler: HandleUserBroadcast,
 234         },
 235         TranDownloadBanner: {
 236                 Name:    "TranDownloadBanner",
 237                 Handler: HandleDownloadBanner,
 238         },
 239 }
 240
 241 func HandleChatSend(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 242         if !cc.Authorize(accessSendChat) {
 243                 res = append(res, cc.NewErrReply(t, "You are not allowed to participate in chat."))
 244                 return res, err
 245         }
 246
 247         // Truncate long usernames
 248         trunc := fmt.Sprintf("%13s", cc.UserName)
 249         formattedMsg := fmt.Sprintf("\r%.14s:  %s", trunc, t.GetField(FieldData).Data)
 250
 251         // By holding the option key, Hotline chat allows users to send /me formatted messages like:
 252         // *** Halcyon does stuff
 253         // This is indicated by the presence of the optional field FieldChatOptions set to a value of 1.
 254         // Most clients do not send this option for normal chat messages.
 255         if t.GetField(FieldChatOptions).Data != nil && bytes.Equal(t.GetField(FieldChatOptions).Data, []byte{0, 1}) {
 256                 formattedMsg = fmt.Sprintf("\r*** %s %s", cc.UserName, t.GetField(FieldData).Data)
 257         }
 258
 259         // The ChatID field is used to identify messages as belonging to a private chat.
 260         // All clients *except* Frogblast omit this field for public chat, but Frogblast sends a value of 00 00 00 00.
 261         chatID := t.GetField(FieldChatID).Data
 262         if chatID != nil && !bytes.Equal([]byte{0, 0, 0, 0}, chatID) {
 263                 chatInt := binary.BigEndian.Uint32(chatID)
 264                 privChat := cc.Server.PrivateChats[chatInt]
 265
 266                 clients := sortedClients(privChat.ClientConn)
 267
 268                 // send the message to all connected clients of the private chat
 269                 for _, c := range clients {
 270                         res = append(res, *NewTransaction(
 271                                 TranChatMsg,
 272                                 c.ID,
 273                                 NewField(FieldChatID, chatID),
 274                                 NewField(FieldData, []byte(formattedMsg)),
 275                         ))
 276                 }
 277                 return res, err
 278         }
 279
 280         for _, c := range sortedClients(cc.Server.Clients) {
 281                 // Filter out clients that do not have the read chat permission
 282                 if c.Authorize(accessReadChat) {
 283                         res = append(res, *NewTransaction(TranChatMsg, c.ID, NewField(FieldData, []byte(formattedMsg))))
 284                 }
 285         }
 286
 287         return res, err
 288 }
 289
 290 // HandleSendInstantMsg sends instant message to the user on the current server.
 291 // Fields used in the request:
 292 //
 293 //      103     User ID
 294 //      113     Options
 295 //              One of the following values:
 296 //              - User message (myOpt_UserMessage = 1)
 297 //              - Refuse message (myOpt_RefuseMessage = 2)
 298 //              - Refuse chat (myOpt_RefuseChat  = 3)
 299 //              - Automatic response (myOpt_AutomaticResponse = 4)"
 300 //      101     Data    Optional
 301 //      214     Quoting message Optional
 302 //
 303 // Fields used in the reply:
 304 // None
 305 func HandleSendInstantMsg(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 306         if !cc.Authorize(accessSendPrivMsg) {
 307                 res = append(res, cc.NewErrReply(t, "You are not allowed to send private messages."))
 308                 return res, errors.New("user is not allowed to send private messages")
 309         }
 310
 311         msg := t.GetField(FieldData)
 312         ID := t.GetField(FieldUserID)
 313
 314         reply := NewTransaction(
 315                 TranServerMsg,
 316                 &ID.Data,
 317                 NewField(FieldData, msg.Data),
 318                 NewField(FieldUserName, cc.UserName),
 319                 NewField(FieldUserID, *cc.ID),
 320                 NewField(FieldOptions, []byte{0, 1}),
 321         )
 322
 323         // Later versions of Hotline include the original message in the FieldQuotingMsg field so
 324         //  the receiving client can display both the received message and what it is in reply to
 325         if t.GetField(FieldQuotingMsg).Data != nil {
 326                 reply.Fields = append(reply.Fields, NewField(FieldQuotingMsg, t.GetField(FieldQuotingMsg).Data))
 327         }
 328
 329         id, err := byteToInt(ID.Data)
 330         if err != nil {
 331                 return res, errors.New("invalid client ID")
 332         }
 333         otherClient, ok := cc.Server.Clients[uint16(id)]
 334         if !ok {
 335                 return res, errors.New("invalid client ID")
 336         }
 337
 338         // Check if target user has "Refuse private messages" flag
 339         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(otherClient.Flags)))
 340         if flagBitmap.Bit(UserFlagRefusePM) == 1 {
 341                 res = append(res,
 342                         *NewTransaction(
 343                                 TranServerMsg,
 344                                 cc.ID,
 345                                 NewField(FieldData, []byte(string(otherClient.UserName)+" does not accept private messages.")),
 346                                 NewField(FieldUserName, otherClient.UserName),
 347                                 NewField(FieldUserID, *otherClient.ID),
 348                                 NewField(FieldOptions, []byte{0, 2}),
 349                         ),
 350                 )
 351         } else {
 352                 res = append(res, *reply)
 353         }
 354
 355         // Respond with auto reply if other client has it enabled
 356         if len(otherClient.AutoReply) > 0 {
 357                 res = append(res,
 358                         *NewTransaction(
 359                                 TranServerMsg,
 360                                 cc.ID,
 361                                 NewField(FieldData, otherClient.AutoReply),
 362                                 NewField(FieldUserName, otherClient.UserName),
 363                                 NewField(FieldUserID, *otherClient.ID),
 364                                 NewField(FieldOptions, []byte{0, 1}),
 365                         ),
 366                 )
 367         }
 368
 369         res = append(res, cc.NewReply(t))
 370
 371         return res, err
 372 }
 373
 374 func HandleGetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 375         fileName := t.GetField(FieldFileName).Data
 376         filePath := t.GetField(FieldFilePath).Data
 377
 378         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 379         if err != nil {
 380                 return res, err
 381         }
 382
 383         fw, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 384         if err != nil {
 385                 return res, err
 386         }
 387
 388         encodedName, err := txtEncoder.String(fw.name)
 389         if err != nil {
 390                 return res, fmt.Errorf("invalid filepath encoding: %w", err)
 391         }
 392
 393         fields := []Field{
 394                 NewField(FieldFileName, []byte(encodedName)),
 395                 NewField(FieldFileTypeString, fw.ffo.FlatFileInformationFork.friendlyType()),
 396                 NewField(FieldFileCreatorString, fw.ffo.FlatFileInformationFork.friendlyCreator()),
 397                 NewField(FieldFileType, fw.ffo.FlatFileInformationFork.TypeSignature),
 398                 NewField(FieldFileCreateDate, fw.ffo.FlatFileInformationFork.CreateDate),
 399                 NewField(FieldFileModifyDate, fw.ffo.FlatFileInformationFork.ModifyDate),
 400         }
 401
 402         // Include the optional FileComment field if there is a comment.
 403         if len(fw.ffo.FlatFileInformationFork.Comment) != 0 {
 404                 fields = append(fields, NewField(FieldFileComment, fw.ffo.FlatFileInformationFork.Comment))
 405         }
 406
 407         // Include the FileSize field for files.
 408         if !bytes.Equal(fw.ffo.FlatFileInformationFork.TypeSignature, []byte{0x66, 0x6c, 0x64, 0x72}) {
 409                 fields = append(fields, NewField(FieldFileSize, fw.totalSize()))
 410         }
 411
 412         res = append(res, cc.NewReply(t, fields...))
 413         return res, err
 414 }
 415
 416 // HandleSetFileInfo updates a file or folder name and/or comment from the Get Info window
 417 // Fields used in the request:
 418 // * 201        File name
 419 // * 202        File path       Optional
 420 // * 211        File new name   Optional
 421 // * 210        File comment    Optional
 422 // Fields used in the reply:    None
 423 func HandleSetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 424         fileName := t.GetField(FieldFileName).Data
 425         filePath := t.GetField(FieldFilePath).Data
 426
 427         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 428         if err != nil {
 429                 return res, err
 430         }
 431
 432         fi, err := cc.Server.FS.Stat(fullFilePath)
 433         if err != nil {
 434                 return res, err
 435         }
 436
 437         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 438         if err != nil {
 439                 return res, err
 440         }
 441         if t.GetField(FieldFileComment).Data != nil {
 442                 switch mode := fi.Mode(); {
 443                 case mode.IsDir():
 444                         if !cc.Authorize(accessSetFolderComment) {
 445                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for folders."))
 446                                 return res, err
 447                         }
 448                 case mode.IsRegular():
 449                         if !cc.Authorize(accessSetFileComment) {
 450                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for files."))
 451                                 return res, err
 452                         }
 453                 }
 454
 455                 if err := hlFile.ffo.FlatFileInformationFork.setComment(t.GetField(FieldFileComment).Data); err != nil {
 456                         return res, err
 457                 }
 458                 w, err := hlFile.infoForkWriter()
 459                 if err != nil {
 460                         return res, err
 461                 }
 462                 _, err = w.Write(hlFile.ffo.FlatFileInformationFork.MarshalBinary())
 463                 if err != nil {
 464                         return res, err
 465                 }
 466         }
 467
 468         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, t.GetField(FieldFileNewName).Data)
 469         if err != nil {
 470                 return nil, err
 471         }
 472
 473         fileNewName := t.GetField(FieldFileNewName).Data
 474
 475         if fileNewName != nil {
 476                 switch mode := fi.Mode(); {
 477                 case mode.IsDir():
 478                         if !cc.Authorize(accessRenameFolder) {
 479                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename folders."))
 480                                 return res, err
 481                         }
 482                         err = os.Rename(fullFilePath, fullNewFilePath)
 483                         if os.IsNotExist(err) {
 484                                 res = append(res, cc.NewErrReply(t, "Cannot rename folder "+string(fileName)+" because it does not exist or cannot be found."))
 485                                 return res, err
 486                         }
 487                 case mode.IsRegular():
 488                         if !cc.Authorize(accessRenameFile) {
 489                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename files."))
 490                                 return res, err
 491                         }
 492                         fileDir, err := readPath(cc.Server.Config.FileRoot, filePath, []byte{})
 493                         if err != nil {
 494                                 return nil, err
 495                         }
 496                         hlFile.name, err = txtDecoder.String(string(fileNewName))
 497                         if err != nil {
 498                                 return res, fmt.Errorf("invalid filepath encoding: %w", err)
 499                         }
 500
 501                         err = hlFile.move(fileDir)
 502                         if os.IsNotExist(err) {
 503                                 res = append(res, cc.NewErrReply(t, "Cannot rename file "+string(fileName)+" because it does not exist or cannot be found."))
 504                                 return res, err
 505                         }
 506                         if err != nil {
 507                                 return res, err
 508                         }
 509                 }
 510         }
 511
 512         res = append(res, cc.NewReply(t))
 513         return res, err
 514 }
 515
 516 // HandleDeleteFile deletes a file or folder
 517 // Fields used in the request:
 518 // * 201        File name
 519 // * 202        File path
 520 // Fields used in the reply: none
 521 func HandleDeleteFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 522         fileName := t.GetField(FieldFileName).Data
 523         filePath := t.GetField(FieldFilePath).Data
 524
 525         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 526         if err != nil {
 527                 return res, err
 528         }
 529
 530         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 531         if err != nil {
 532                 return res, err
 533         }
 534
 535         fi, err := hlFile.dataFile()
 536         if err != nil {
 537                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+string(fileName)+" because it does not exist or cannot be found."))
 538                 return res, nil
 539         }
 540
 541         switch mode := fi.Mode(); {
 542         case mode.IsDir():
 543                 if !cc.Authorize(accessDeleteFolder) {
 544                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete folders."))
 545                         return res, err
 546                 }
 547         case mode.IsRegular():
 548                 if !cc.Authorize(accessDeleteFile) {
 549                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete files."))
 550                         return res, err
 551                 }
 552         }
 553
 554         if err := hlFile.delete(); err != nil {
 555                 return res, err
 556         }
 557
 558         res = append(res, cc.NewReply(t))
 559         return res, err
 560 }
 561
 562 // HandleMoveFile moves files or folders. Note: seemingly not documented
 563 func HandleMoveFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 564         fileName := string(t.GetField(FieldFileName).Data)
 565
 566         filePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(FieldFilePath).Data, t.GetField(FieldFileName).Data)
 567         if err != nil {
 568                 return res, err
 569         }
 570
 571         fileNewPath, err := readPath(cc.Server.Config.FileRoot, t.GetField(FieldFileNewPath).Data, nil)
 572         if err != nil {
 573                 return res, err
 574         }
 575
 576         cc.logger.Infow("Move file", "src", filePath+"/"+fileName, "dst", fileNewPath+"/"+fileName)
 577
 578         hlFile, err := newFileWrapper(cc.Server.FS, filePath, 0)
 579         if err != nil {
 580                 return res, err
 581         }
 582
 583         fi, err := hlFile.dataFile()
 584         if err != nil {
 585                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+fileName+" because it does not exist or cannot be found."))
 586                 return res, err
 587         }
 588         switch mode := fi.Mode(); {
 589         case mode.IsDir():
 590                 if !cc.Authorize(accessMoveFolder) {
 591                         res = append(res, cc.NewErrReply(t, "You are not allowed to move folders."))
 592                         return res, err
 593                 }
 594         case mode.IsRegular():
 595                 if !cc.Authorize(accessMoveFile) {
 596                         res = append(res, cc.NewErrReply(t, "You are not allowed to move files."))
 597                         return res, err
 598                 }
 599         }
 600         if err := hlFile.move(fileNewPath); err != nil {
 601                 return res, err
 602         }
 603         // TODO: handle other possible errors; e.g. fileWrapper delete fails due to fileWrapper permission issue
 604
 605         res = append(res, cc.NewReply(t))
 606         return res, err
 607 }
 608
 609 func HandleNewFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 610         if !cc.Authorize(accessCreateFolder) {
 611                 res = append(res, cc.NewErrReply(t, "You are not allowed to create folders."))
 612                 return res, err
 613         }
 614         folderName := string(t.GetField(FieldFileName).Data)
 615
 616         folderName = path.Join("/", folderName)
 617
 618         var subPath string
 619
 620         // FieldFilePath is only present for nested paths
 621         if t.GetField(FieldFilePath).Data != nil {
 622                 var newFp FilePath
 623                 _, err := newFp.Write(t.GetField(FieldFilePath).Data)
 624                 if err != nil {
 625                         return nil, err
 626                 }
 627
 628                 for _, pathItem := range newFp.Items {
 629                         subPath = filepath.Join("/", subPath, string(pathItem.Name))
 630                 }
 631         }
 632         newFolderPath := path.Join(cc.Server.Config.FileRoot, subPath, folderName)
 633         newFolderPath, err = txtDecoder.String(newFolderPath)
 634         if err != nil {
 635                 return res, fmt.Errorf("invalid filepath encoding: %w", err)
 636         }
 637
 638         // TODO: check path and folder name lengths
 639
 640         if _, err := cc.Server.FS.Stat(newFolderPath); !os.IsNotExist(err) {
 641                 msg := fmt.Sprintf("Cannot create folder \"%s\" because there is already a file or folder with that name.", folderName)
 642                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 643         }
 644
 645         if err := cc.Server.FS.Mkdir(newFolderPath, 0777); err != nil {
 646                 msg := fmt.Sprintf("Cannot create folder \"%s\" because an error occurred.", folderName)
 647                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 648         }
 649
 650         res = append(res, cc.NewReply(t))
 651         return res, err
 652 }
 653
 654 func HandleSetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 655         if !cc.Authorize(accessModifyUser) {
 656                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 657                 return res, err
 658         }
 659
 660         login := decodeString(t.GetField(FieldUserLogin).Data)
 661         userName := string(t.GetField(FieldUserName).Data)
 662
 663         newAccessLvl := t.GetField(FieldUserAccess).Data
 664
 665         account := cc.Server.Accounts[login]
 666         account.Name = userName
 667         copy(account.Access[:], newAccessLvl)
 668
 669         // If the password field is cleared in the Hotline edit user UI, the SetUser transaction does
 670         // not include FieldUserPassword
 671         if t.GetField(FieldUserPassword).Data == nil {
 672                 account.Password = hashAndSalt([]byte(""))
 673         }
 674         if len(t.GetField(FieldUserPassword).Data) > 1 {
 675                 account.Password = hashAndSalt(t.GetField(FieldUserPassword).Data)
 676         }
 677
 678         out, err := yaml.Marshal(&account)
 679         if err != nil {
 680                 return res, err
 681         }
 682         if err := os.WriteFile(filepath.Join(cc.Server.ConfigDir, "Users", login+".yaml"), out, 0666); err != nil {
 683                 return res, err
 684         }
 685
 686         // Notify connected clients logged in as the user of the new access level
 687         for _, c := range cc.Server.Clients {
 688                 if c.Account.Login == login {
 689                         // Note: comment out these two lines to test server-side deny messages
 690                         newT := NewTransaction(TranUserAccess, c.ID, NewField(FieldUserAccess, newAccessLvl))
 691                         res = append(res, *newT)
 692
 693                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(c.Flags)))
 694                         if c.Authorize(accessDisconUser) {
 695                                 flagBitmap.SetBit(flagBitmap, UserFlagAdmin, 1)
 696                         } else {
 697                                 flagBitmap.SetBit(flagBitmap, UserFlagAdmin, 0)
 698                         }
 699                         binary.BigEndian.PutUint16(c.Flags, uint16(flagBitmap.Int64()))
 700
 701                         c.Account.Access = account.Access
 702
 703                         cc.sendAll(
 704                                 TranNotifyChangeUser,
 705                                 NewField(FieldUserID, *c.ID),
 706                                 NewField(FieldUserFlags, c.Flags),
 707                                 NewField(FieldUserName, c.UserName),
 708                                 NewField(FieldUserIconID, c.Icon),
 709                         )
 710                 }
 711         }
 712
 713         res = append(res, cc.NewReply(t))
 714         return res, err
 715 }
 716
 717 func HandleGetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 718         if !cc.Authorize(accessOpenUser) {
 719                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 720                 return res, err
 721         }
 722
 723         account := cc.Server.Accounts[string(t.GetField(FieldUserLogin).Data)]
 724         if account == nil {
 725                 res = append(res, cc.NewErrReply(t, "Account does not exist."))
 726                 return res, err
 727         }
 728
 729         res = append(res, cc.NewReply(t,
 730                 NewField(FieldUserName, []byte(account.Name)),
 731                 NewField(FieldUserLogin, encodeString(t.GetField(FieldUserLogin).Data)),
 732                 NewField(FieldUserPassword, []byte(account.Password)),
 733                 NewField(FieldUserAccess, account.Access[:]),
 734         ))
 735         return res, err
 736 }
 737
 738 func HandleListUsers(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 739         if !cc.Authorize(accessOpenUser) {
 740                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 741                 return res, err
 742         }
 743
 744         var userFields []Field
 745         for _, acc := range cc.Server.Accounts {
 746                 b := make([]byte, 0, 100)
 747                 n, err := acc.Read(b)
 748                 if err != nil {
 749                         return res, err
 750                 }
 751
 752                 userFields = append(userFields, NewField(FieldData, b[:n]))
 753         }
 754
 755         res = append(res, cc.NewReply(t, userFields...))
 756         return res, err
 757 }
 758
 759 // HandleUpdateUser is used by the v1.5+ multi-user editor to perform account editing for multiple users at a time.
 760 // An update can be a mix of these actions:
 761 // * Create user
 762 // * Delete user
 763 // * Modify user (including renaming the account login)
 764 //
 765 // The Transaction sent by the client includes one data field per user that was modified.  This data field in turn
 766 // contains another data field encoded in its payload with a varying number of sub fields depending on which action is
 767 // performed.  This seems to be the only place in the Hotline protocol where a data field contains another data field.
 768 func HandleUpdateUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 769         for _, field := range t.Fields {
 770                 subFields, err := ReadFields(field.Data[0:2], field.Data[2:])
 771                 if err != nil {
 772                         return res, err
 773                 }
 774
 775                 if len(subFields) == 1 {
 776                         login := decodeString(getField(FieldData, &subFields).Data)
 777                         cc.logger.Infow("DeleteUser", "login", login)
 778
 779                         if !cc.Authorize(accessDeleteUser) {
 780                                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 781                                 return res, err
 782                         }
 783
 784                         if err := cc.Server.DeleteUser(login); err != nil {
 785                                 return res, err
 786                         }
 787                         continue
 788                 }
 789
 790                 login := decodeString(getField(FieldUserLogin, &subFields).Data)
 791
 792                 // check if the login dataFile; if so, we know we are updating an existing user
 793                 if acc, ok := cc.Server.Accounts[login]; ok {
 794                         cc.logger.Infow("UpdateUser", "login", login)
 795
 796                         // account exists, so this is an update action
 797                         if !cc.Authorize(accessModifyUser) {
 798                                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 799                                 return res, err
 800                         }
 801
 802                         // This part is a bit tricky. There are three possibilities:
 803                         // 1) The transaction is intended to update the password.
 804                         //        In this case, FieldUserPassword is sent with the new password.
 805                         // 2) The transaction is intended to remove the password.
 806                         //    In this case, FieldUserPassword is not sent.
 807                         // 3) The transaction updates the users access bits, but not the password.
 808                         //    In this case, FieldUserPassword is sent with zero as the only byte..
 809                         if getField(FieldUserPassword, &subFields) != nil {
 810                                 newPass := getField(FieldUserPassword, &subFields).Data
 811                                 if !bytes.Equal([]byte{0}, newPass) {
 812                                         acc.Password = hashAndSalt(newPass)
 813                                 }
 814                         } else {
 815                                 acc.Password = hashAndSalt([]byte(""))
 816                         }
 817
 818                         if getField(FieldUserAccess, &subFields) != nil {
 819                                 copy(acc.Access[:], getField(FieldUserAccess, &subFields).Data)
 820                         }
 821
 822                         err = cc.Server.UpdateUser(
 823                                 decodeString(getField(FieldData, &subFields).Data),
 824                                 decodeString(getField(FieldUserLogin, &subFields).Data),
 825                                 string(getField(FieldUserName, &subFields).Data),
 826                                 acc.Password,
 827                                 acc.Access,
 828                         )
 829                         if err != nil {
 830                                 return res, err
 831                         }
 832                 } else {
 833                         cc.logger.Infow("CreateUser", "login", login)
 834
 835                         if !cc.Authorize(accessCreateUser) {
 836                                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 837                                 return res, err
 838                         }
 839
 840                         newAccess := accessBitmap{}
 841                         copy(newAccess[:], getField(FieldUserAccess, &subFields).Data)
 842
 843                         // Prevent account from creating new account with greater permission
 844                         for i := 0; i < 64; i++ {
 845                                 if newAccess.IsSet(i) {
 846                                         if !cc.Authorize(i) {
 847                                                 return append(res, cc.NewErrReply(t, "Cannot create account with more access than yourself.")), err
 848                                         }
 849                                 }
 850                         }
 851
 852                         err := cc.Server.NewUser(login, string(getField(FieldUserName, &subFields).Data), string(getField(FieldUserPassword, &subFields).Data), newAccess)
 853                         if err != nil {
 854                                 return []Transaction{}, err
 855                         }
 856                 }
 857         }
 858
 859         res = append(res, cc.NewReply(t))
 860         return res, err
 861 }
 862
 863 // HandleNewUser creates a new user account
 864 func HandleNewUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 865         if !cc.Authorize(accessCreateUser) {
 866                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 867                 return res, err
 868         }
 869
 870         login := decodeString(t.GetField(FieldUserLogin).Data)
 871
 872         // If the account already dataFile, reply with an error
 873         if _, ok := cc.Server.Accounts[login]; ok {
 874                 res = append(res, cc.NewErrReply(t, "Cannot create account "+login+" because there is already an account with that login."))
 875                 return res, err
 876         }
 877
 878         newAccess := accessBitmap{}
 879         copy(newAccess[:], t.GetField(FieldUserAccess).Data)
 880
 881         // Prevent account from creating new account with greater permission
 882         for i := 0; i < 64; i++ {
 883                 if newAccess.IsSet(i) {
 884                         if !cc.Authorize(i) {
 885                                 res = append(res, cc.NewErrReply(t, "Cannot create account with more access than yourself."))
 886                                 return res, err
 887                         }
 888                 }
 889         }
 890
 891         if err := cc.Server.NewUser(login, string(t.GetField(FieldUserName).Data), string(t.GetField(FieldUserPassword).Data), newAccess); err != nil {
 892                 return []Transaction{}, err
 893         }
 894
 895         res = append(res, cc.NewReply(t))
 896         return res, err
 897 }
 898
 899 func HandleDeleteUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 900         if !cc.Authorize(accessDeleteUser) {
 901                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 902                 return res, err
 903         }
 904
 905         // TODO: Handle case where account doesn't exist; e.g. delete race condition
 906         login := decodeString(t.GetField(FieldUserLogin).Data)
 907
 908         if err := cc.Server.DeleteUser(login); err != nil {
 909                 return res, err
 910         }
 911
 912         res = append(res, cc.NewReply(t))
 913         return res, err
 914 }
 915
 916 // HandleUserBroadcast sends an Administrator Message to all connected clients of the server
 917 func HandleUserBroadcast(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 918         if !cc.Authorize(accessBroadcast) {
 919                 res = append(res, cc.NewErrReply(t, "You are not allowed to send broadcast messages."))
 920                 return res, err
 921         }
 922
 923         cc.sendAll(
 924                 TranServerMsg,
 925                 NewField(FieldData, t.GetField(TranGetMsgs).Data),
 926                 NewField(FieldChatOptions, []byte{0}),
 927         )
 928
 929         res = append(res, cc.NewReply(t))
 930         return res, err
 931 }
 932
 933 // HandleGetClientInfoText returns user information for the specific user.
 934 //
 935 // Fields used in the request:
 936 // 103  User ID
 937 //
 938 // Fields used in the reply:
 939 // 102  User name
 940 // 101  Data            User info text string
 941 func HandleGetClientInfoText(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 942         if !cc.Authorize(accessGetClientInfo) {
 943                 res = append(res, cc.NewErrReply(t, "You are not allowed to get client info."))
 944                 return res, err
 945         }
 946
 947         clientID, _ := byteToInt(t.GetField(FieldUserID).Data)
 948
 949         clientConn := cc.Server.Clients[uint16(clientID)]
 950         if clientConn == nil {
 951                 return append(res, cc.NewErrReply(t, "User not found.")), err
 952         }
 953
 954         res = append(res, cc.NewReply(t,
 955                 NewField(FieldData, []byte(clientConn.String())),
 956                 NewField(FieldUserName, clientConn.UserName),
 957         ))
 958         return res, err
 959 }
 960
 961 func HandleGetUserNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 962         res = append(res, cc.NewReply(t, cc.Server.connectedUsers()...))
 963
 964         return res, err
 965 }
 966
 967 func HandleTranAgreed(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 968         if t.GetField(FieldUserName).Data != nil {
 969                 if cc.Authorize(accessAnyName) {
 970                         cc.UserName = t.GetField(FieldUserName).Data
 971                 } else {
 972                         cc.UserName = []byte(cc.Account.Name)
 973                 }
 974         }
 975
 976         cc.Icon = t.GetField(FieldUserIconID).Data
 977
 978         cc.logger = cc.logger.With("name", string(cc.UserName))
 979         cc.logger.Infow("Login successful", "clientVersion", fmt.Sprintf("%v", func() int { i, _ := byteToInt(cc.Version); return i }()))
 980
 981         options := t.GetField(FieldOptions).Data
 982         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 983
 984         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
 985
 986         // Check refuse private PM option
 987         if optBitmap.Bit(refusePM) == 1 {
 988                 flagBitmap.SetBit(flagBitmap, UserFlagRefusePM, 1)
 989                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 990         }
 991
 992         // Check refuse private chat option
 993         if optBitmap.Bit(refuseChat) == 1 {
 994                 flagBitmap.SetBit(flagBitmap, UserFlagRefusePChat, 1)
 995                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 996         }
 997
 998         // Check auto response
 999         if optBitmap.Bit(autoResponse) == 1 {
1000                 cc.AutoReply = t.GetField(FieldAutomaticResponse).Data
1001         } else {
1002                 cc.AutoReply = []byte{}
1003         }
1004
1005         trans := cc.notifyOthers(
1006                 *NewTransaction(
1007                         TranNotifyChangeUser, nil,
1008                         NewField(FieldUserName, cc.UserName),
1009                         NewField(FieldUserID, *cc.ID),
1010                         NewField(FieldUserIconID, cc.Icon),
1011                         NewField(FieldUserFlags, cc.Flags),
1012                 ),
1013         )
1014         res = append(res, trans...)
1015
1016         if cc.Server.Config.BannerFile != "" {
1017                 res = append(res, *NewTransaction(TranServerBanner, cc.ID, NewField(FieldBannerType, []byte("JPEG"))))
1018         }
1019
1020         res = append(res, cc.NewReply(t))
1021
1022         return res, err
1023 }
1024
1025 // HandleTranOldPostNews updates the flat news
1026 // Fields used in this request:
1027 // 101  Data
1028 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1029         if !cc.Authorize(accessNewsPostArt) {
1030                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
1031                 return res, err
1032         }
1033
1034         cc.Server.flatNewsMux.Lock()
1035         defer cc.Server.flatNewsMux.Unlock()
1036
1037         newsDateTemplate := defaultNewsDateFormat
1038         if cc.Server.Config.NewsDateFormat != "" {
1039                 newsDateTemplate = cc.Server.Config.NewsDateFormat
1040         }
1041
1042         newsTemplate := defaultNewsTemplate
1043         if cc.Server.Config.NewsDelimiter != "" {
1044                 newsTemplate = cc.Server.Config.NewsDelimiter
1045         }
1046
1047         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(FieldData).Data)
1048         newsPost = strings.ReplaceAll(newsPost, "\n", "\r")
1049
1050         // update news in memory
1051         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
1052
1053         // update news on disk
1054         if err := cc.Server.FS.WriteFile(filepath.Join(cc.Server.ConfigDir, "MessageBoard.txt"), cc.Server.FlatNews, 0644); err != nil {
1055                 return res, err
1056         }
1057
1058         // Notify all clients of updated news
1059         cc.sendAll(
1060                 TranNewMsg,
1061                 NewField(FieldData, []byte(newsPost)),
1062         )
1063
1064         res = append(res, cc.NewReply(t))
1065         return res, err
1066 }
1067
1068 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1069         if !cc.Authorize(accessDisconUser) {
1070                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1071                 return res, err
1072         }
1073
1074         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(FieldUserID).Data)]
1075
1076         if clientConn.Authorize(accessCannotBeDiscon) {
1077                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1078                 return res, err
1079         }
1080
1081         // If FieldOptions is set, then the client IP is banned in addition to disconnected.
1082         // 00 01 = temporary ban
1083         // 00 02 = permanent ban
1084         if t.GetField(FieldOptions).Data != nil {
1085                 switch t.GetField(FieldOptions).Data[1] {
1086                 case 1:
1087                         // send message: "You are temporarily banned on this server"
1088                         cc.logger.Infow("Disconnect & temporarily ban " + string(clientConn.UserName))
1089
1090                         res = append(res, *NewTransaction(
1091                                 TranServerMsg,
1092                                 clientConn.ID,
1093                                 NewField(FieldData, []byte("You are temporarily banned on this server")),
1094                                 NewField(FieldChatOptions, []byte{0, 0}),
1095                         ))
1096
1097                         banUntil := time.Now().Add(tempBanDuration)
1098                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = &banUntil
1099                 case 2:
1100                         // send message: "You are permanently banned on this server"
1101                         cc.logger.Infow("Disconnect & ban " + string(clientConn.UserName))
1102
1103                         res = append(res, *NewTransaction(
1104                                 TranServerMsg,
1105                                 clientConn.ID,
1106                                 NewField(FieldData, []byte("You are permanently banned on this server")),
1107                                 NewField(FieldChatOptions, []byte{0, 0}),
1108                         ))
1109
1110                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = nil
1111                 }
1112
1113                 err := cc.Server.writeBanList()
1114                 if err != nil {
1115                         return res, err
1116                 }
1117         }
1118
1119         // TODO: remove this awful hack
1120         go func() {
1121                 time.Sleep(1 * time.Second)
1122                 clientConn.Disconnect()
1123         }()
1124
1125         return append(res, cc.NewReply(t)), err
1126 }
1127
1128 // HandleGetNewsCatNameList returns a list of news categories for a path
1129 // Fields used in the request:
1130 // 325  News path       (Optional)
1131 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1132         if !cc.Authorize(accessNewsReadArt) {
1133                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1134                 return res, err
1135         }
1136
1137         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1138         cats := cc.Server.GetNewsCatByPath(pathStrs)
1139
1140         // To store the keys in slice in sorted order
1141         keys := make([]string, len(cats))
1142         i := 0
1143         for k := range cats {
1144                 keys[i] = k
1145                 i++
1146         }
1147         sort.Strings(keys)
1148
1149         var fieldData []Field
1150         for _, k := range keys {
1151                 cat := cats[k]
1152                 b, _ := cat.MarshalBinary()
1153                 fieldData = append(fieldData, NewField(
1154                         FieldNewsCatListData15,
1155                         b,
1156                 ))
1157         }
1158
1159         res = append(res, cc.NewReply(t, fieldData...))
1160         return res, err
1161 }
1162
1163 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1164         if !cc.Authorize(accessNewsCreateCat) {
1165                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1166                 return res, err
1167         }
1168
1169         name := string(t.GetField(FieldNewsCatName).Data)
1170         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1171
1172         cats := cc.Server.GetNewsCatByPath(pathStrs)
1173         cats[name] = NewsCategoryListData15{
1174                 Name:     name,
1175                 Type:     []byte{0, 3},
1176                 Articles: map[uint32]*NewsArtData{},
1177                 SubCats:  make(map[string]NewsCategoryListData15),
1178         }
1179
1180         if err := cc.Server.writeThreadedNews(); err != nil {
1181                 return res, err
1182         }
1183         res = append(res, cc.NewReply(t))
1184         return res, err
1185 }
1186
1187 // Fields used in the request:
1188 // 322  News category name
1189 // 325  News path
1190 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1191         if !cc.Authorize(accessNewsCreateFldr) {
1192                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1193                 return res, err
1194         }
1195
1196         name := string(t.GetField(FieldFileName).Data)
1197         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1198
1199         cc.logger.Infof("Creating new news folder %s", name)
1200
1201         cats := cc.Server.GetNewsCatByPath(pathStrs)
1202         cats[name] = NewsCategoryListData15{
1203                 Name:     name,
1204                 Type:     []byte{0, 2},
1205                 Articles: map[uint32]*NewsArtData{},
1206                 SubCats:  make(map[string]NewsCategoryListData15),
1207         }
1208         if err := cc.Server.writeThreadedNews(); err != nil {
1209                 return res, err
1210         }
1211         res = append(res, cc.NewReply(t))
1212         return res, err
1213 }
1214
1215 // HandleGetNewsArtData gets the list of article names at the specified news path.
1216
1217 // Fields used in the request:
1218 // 325  News path       Optional
1219
1220 // Fields used in the reply:
1221 // 321  News article list data  Optional
1222 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1223         if !cc.Authorize(accessNewsReadArt) {
1224                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1225                 return res, err
1226         }
1227         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1228
1229         var cat NewsCategoryListData15
1230         cats := cc.Server.ThreadedNews.Categories
1231
1232         for _, fp := range pathStrs {
1233                 cat = cats[fp]
1234                 cats = cats[fp].SubCats
1235         }
1236
1237         nald := cat.GetNewsArtListData()
1238
1239         res = append(res, cc.NewReply(t, NewField(FieldNewsArtListData, nald.Payload())))
1240         return res, err
1241 }
1242
1243 // HandleGetNewsArtData requests information about the specific news article.
1244 // Fields used in the request:
1245 //
1246 // Request fields
1247 // 325  News path
1248 // 326  News article ID
1249 // 327  News article data flavor
1250 //
1251 // Fields used in the reply:
1252 // 328  News article title
1253 // 329  News article poster
1254 // 330  News article date
1255 // 331  Previous article ID
1256 // 332  Next article ID
1257 // 335  Parent article ID
1258 // 336  First child article ID
1259 // 327  News article data flavor        "Should be “text/plain”
1260 // 333  News article data       Optional (if data flavor is “text/plain”)
1261 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1262         if !cc.Authorize(accessNewsReadArt) {
1263                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1264                 return res, err
1265         }
1266
1267         var cat NewsCategoryListData15
1268         cats := cc.Server.ThreadedNews.Categories
1269
1270         for _, fp := range ReadNewsPath(t.GetField(FieldNewsPath).Data) {
1271                 cat = cats[fp]
1272                 cats = cats[fp].SubCats
1273         }
1274
1275         // The official Hotline clients will send the article ID as 2 bytes if possible, but
1276         // some third party clients such as Frogblast and Heildrun will always send 4 bytes
1277         convertedID, err := byteToInt(t.GetField(FieldNewsArtID).Data)
1278         if err != nil {
1279                 return res, err
1280         }
1281
1282         art := cat.Articles[uint32(convertedID)]
1283         if art == nil {
1284                 res = append(res, cc.NewReply(t))
1285                 return res, err
1286         }
1287
1288         res = append(res, cc.NewReply(t,
1289                 NewField(FieldNewsArtTitle, []byte(art.Title)),
1290                 NewField(FieldNewsArtPoster, []byte(art.Poster)),
1291                 NewField(FieldNewsArtDate, art.Date),
1292                 NewField(FieldNewsArtPrevArt, art.PrevArt),
1293                 NewField(FieldNewsArtNextArt, art.NextArt),
1294                 NewField(FieldNewsArtParentArt, art.ParentArt),
1295                 NewField(FieldNewsArt1stChildArt, art.FirstChildArt),
1296                 NewField(FieldNewsArtDataFlav, []byte("text/plain")),
1297                 NewField(FieldNewsArtData, []byte(art.Data)),
1298         ))
1299         return res, err
1300 }
1301
1302 // HandleDelNewsItem deletes an existing threaded news folder or category from the server.
1303 // Fields used in the request:
1304 // 325  News path
1305 // Fields used in the reply:
1306 // None
1307 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1308         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1309
1310         cats := cc.Server.ThreadedNews.Categories
1311         delName := pathStrs[len(pathStrs)-1]
1312         if len(pathStrs) > 1 {
1313                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1314                         cats = cats[fp].SubCats
1315                 }
1316         }
1317
1318         if bytes.Equal(cats[delName].Type, []byte{0, 3}) {
1319                 if !cc.Authorize(accessNewsDeleteCat) {
1320                         return append(res, cc.NewErrReply(t, "You are not allowed to delete news categories.")), nil
1321                 }
1322         } else {
1323                 if !cc.Authorize(accessNewsDeleteFldr) {
1324                         return append(res, cc.NewErrReply(t, "You are not allowed to delete news folders.")), nil
1325                 }
1326         }
1327
1328         delete(cats, delName)
1329
1330         if err := cc.Server.writeThreadedNews(); err != nil {
1331                 return res, err
1332         }
1333
1334         return append(res, cc.NewReply(t)), nil
1335 }
1336
1337 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1338         if !cc.Authorize(accessNewsDeleteArt) {
1339                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1340                 return res, err
1341         }
1342
1343         // Request Fields
1344         // 325  News path
1345         // 326  News article ID
1346         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1347         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1348         ID, err := byteToInt(t.GetField(FieldNewsArtID).Data)
1349         if err != nil {
1350                 return res, err
1351         }
1352
1353         // TODO: Delete recursive
1354         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1355
1356         catName := pathStrs[len(pathStrs)-1]
1357         cat := cats[catName]
1358
1359         delete(cat.Articles, uint32(ID))
1360
1361         cats[catName] = cat
1362         if err := cc.Server.writeThreadedNews(); err != nil {
1363                 return res, err
1364         }
1365
1366         res = append(res, cc.NewReply(t))
1367         return res, err
1368 }
1369
1370 // Request fields
1371 // 325  News path
1372 // 326  News article ID                                                 ID of the parent article?
1373 // 328  News article title
1374 // 334  News article flags
1375 // 327  News article data flavor                Currently “text/plain”
1376 // 333  News article data
1377 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1378         if !cc.Authorize(accessNewsPostArt) {
1379                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1380                 return res, err
1381         }
1382
1383         pathStrs := ReadNewsPath(t.GetField(FieldNewsPath).Data)
1384         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1385
1386         catName := pathStrs[len(pathStrs)-1]
1387         cat := cats[catName]
1388
1389         artID, err := byteToInt(t.GetField(FieldNewsArtID).Data)
1390         if err != nil {
1391                 return res, err
1392         }
1393         convertedArtID := uint32(artID)
1394         bs := make([]byte, 4)
1395         binary.BigEndian.PutUint32(bs, convertedArtID)
1396
1397         newArt := NewsArtData{
1398                 Title:         string(t.GetField(FieldNewsArtTitle).Data),
1399                 Poster:        string(cc.UserName),
1400                 Date:          toHotlineTime(time.Now()),
1401                 PrevArt:       []byte{0, 0, 0, 0},
1402                 NextArt:       []byte{0, 0, 0, 0},
1403                 ParentArt:     bs,
1404                 FirstChildArt: []byte{0, 0, 0, 0},
1405                 DataFlav:      []byte("text/plain"),
1406                 Data:          string(t.GetField(FieldNewsArtData).Data),
1407         }
1408
1409         var keys []int
1410         for k := range cat.Articles {
1411                 keys = append(keys, int(k))
1412         }
1413
1414         nextID := uint32(1)
1415         if len(keys) > 0 {
1416                 sort.Ints(keys)
1417                 prevID := uint32(keys[len(keys)-1])
1418                 nextID = prevID + 1
1419
1420                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1421
1422                 // Set next article ID
1423                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1424         }
1425
1426         // Update parent article with first child reply
1427         parentID := convertedArtID
1428         if parentID != 0 {
1429                 parentArt := cat.Articles[parentID]
1430
1431                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1432                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1433                 }
1434         }
1435
1436         cat.Articles[nextID] = &newArt
1437
1438         cats[catName] = cat
1439         if err := cc.Server.writeThreadedNews(); err != nil {
1440                 return res, err
1441         }
1442
1443         res = append(res, cc.NewReply(t))
1444         return res, err
1445 }
1446
1447 // HandleGetMsgs returns the flat news data
1448 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1449         if !cc.Authorize(accessNewsReadArt) {
1450                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1451                 return res, err
1452         }
1453
1454         res = append(res, cc.NewReply(t, NewField(FieldData, cc.Server.FlatNews)))
1455
1456         return res, err
1457 }
1458
1459 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1460         if !cc.Authorize(accessDownloadFile) {
1461                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1462                 return res, err
1463         }
1464
1465         fileName := t.GetField(FieldFileName).Data
1466         filePath := t.GetField(FieldFilePath).Data
1467         resumeData := t.GetField(FieldFileResumeData).Data
1468
1469         var dataOffset int64
1470         var frd FileResumeData
1471         if resumeData != nil {
1472                 if err := frd.UnmarshalBinary(t.GetField(FieldFileResumeData).Data); err != nil {
1473                         return res, err
1474                 }
1475                 // TODO: handle rsrc fork offset
1476                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1477         }
1478
1479         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1480         if err != nil {
1481                 return res, err
1482         }
1483
1484         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1485         if err != nil {
1486                 return res, err
1487         }
1488
1489         xferSize := hlFile.ffo.TransferSize(0)
1490
1491         ft := cc.newFileTransfer(FileDownload, fileName, filePath, xferSize)
1492
1493         // TODO: refactor to remove this
1494         if resumeData != nil {
1495                 var frd FileResumeData
1496                 if err := frd.UnmarshalBinary(t.GetField(FieldFileResumeData).Data); err != nil {
1497                         return res, err
1498                 }
1499                 ft.fileResumeData = &frd
1500         }
1501
1502         // Optional field for when a HL v1.5+ client requests file preview
1503         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1504         // The value will always be 2
1505         if t.GetField(FieldFileTransferOptions).Data != nil {
1506                 ft.options = t.GetField(FieldFileTransferOptions).Data
1507                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1508         }
1509
1510         res = append(res, cc.NewReply(t,
1511                 NewField(FieldRefNum, ft.refNum[:]),
1512                 NewField(FieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1513                 NewField(FieldTransferSize, xferSize),
1514                 NewField(FieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1515         ))
1516
1517         return res, err
1518 }
1519
1520 // Download all files from the specified folder and sub-folders
1521 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1522         if !cc.Authorize(accessDownloadFile) {
1523                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1524                 return res, err
1525         }
1526
1527         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(FieldFilePath).Data, t.GetField(FieldFileName).Data)
1528         if err != nil {
1529                 return res, err
1530         }
1531
1532         transferSize, err := CalcTotalSize(fullFilePath)
1533         if err != nil {
1534                 return res, err
1535         }
1536         itemCount, err := CalcItemCount(fullFilePath)
1537         if err != nil {
1538                 return res, err
1539         }
1540
1541         fileTransfer := cc.newFileTransfer(FolderDownload, t.GetField(FieldFileName).Data, t.GetField(FieldFilePath).Data, transferSize)
1542
1543         var fp FilePath
1544         _, err = fp.Write(t.GetField(FieldFilePath).Data)
1545         if err != nil {
1546                 return res, err
1547         }
1548
1549         res = append(res, cc.NewReply(t,
1550                 NewField(FieldRefNum, fileTransfer.ReferenceNumber),
1551                 NewField(FieldTransferSize, transferSize),
1552                 NewField(FieldFolderItemCount, itemCount),
1553                 NewField(FieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1554         ))
1555         return res, err
1556 }
1557
1558 // Upload all files from the local folder and its subfolders to the specified path on the server
1559 // Fields used in the request
1560 // 201  File name
1561 // 202  File path
1562 // 108  transfer size   Total size of all items in the folder
1563 // 220  Folder item count
1564 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1565 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1566         var fp FilePath
1567         if t.GetField(FieldFilePath).Data != nil {
1568                 if _, err = fp.Write(t.GetField(FieldFilePath).Data); err != nil {
1569                         return res, err
1570                 }
1571         }
1572
1573         // Handle special cases for Upload and Drop Box folders
1574         if !cc.Authorize(accessUploadAnywhere) {
1575                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1576                         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))))
1577                         return res, err
1578                 }
1579         }
1580
1581         fileTransfer := cc.newFileTransfer(FolderUpload,
1582                 t.GetField(FieldFileName).Data,
1583                 t.GetField(FieldFilePath).Data,
1584                 t.GetField(FieldTransferSize).Data,
1585         )
1586
1587         fileTransfer.FolderItemCount = t.GetField(FieldFolderItemCount).Data
1588
1589         res = append(res, cc.NewReply(t, NewField(FieldRefNum, fileTransfer.ReferenceNumber)))
1590         return res, err
1591 }
1592
1593 // HandleUploadFile
1594 // Fields used in the request:
1595 // 201  File name
1596 // 202  File path
1597 // 204  File transfer options   "Optional
1598 // Used only to resume download, currently has value 2"
1599 // 108  File transfer size      "Optional used if download is not resumed"
1600 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1601         if !cc.Authorize(accessUploadFile) {
1602                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1603                 return res, err
1604         }
1605
1606         fileName := t.GetField(FieldFileName).Data
1607         filePath := t.GetField(FieldFilePath).Data
1608         transferOptions := t.GetField(FieldFileTransferOptions).Data
1609         transferSize := t.GetField(FieldTransferSize).Data // not sent for resume
1610
1611         var fp FilePath
1612         if filePath != nil {
1613                 if _, err = fp.Write(filePath); err != nil {
1614                         return res, err
1615                 }
1616         }
1617
1618         // Handle special cases for Upload and Drop Box folders
1619         if !cc.Authorize(accessUploadAnywhere) {
1620                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1621                         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))))
1622                         return res, err
1623                 }
1624         }
1625         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1626         if err != nil {
1627                 return res, err
1628         }
1629
1630         if _, err := cc.Server.FS.Stat(fullFilePath); err == nil {
1631                 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))))
1632                 return res, err
1633         }
1634
1635         ft := cc.newFileTransfer(FileUpload, fileName, filePath, transferSize)
1636
1637         replyT := cc.NewReply(t, NewField(FieldRefNum, ft.ReferenceNumber))
1638
1639         // client has requested to resume a partially transferred file
1640         if transferOptions != nil {
1641                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1642                 if err != nil {
1643                         return res, err
1644                 }
1645
1646                 offset := make([]byte, 4)
1647                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1648
1649                 fileResumeData := NewFileResumeData([]ForkInfoList{
1650                         *NewForkInfoList(offset),
1651                 })
1652
1653                 b, _ := fileResumeData.BinaryMarshal()
1654
1655                 ft.TransferSize = offset
1656
1657                 replyT.Fields = append(replyT.Fields, NewField(FieldFileResumeData, b))
1658         }
1659
1660         res = append(res, replyT)
1661         return res, err
1662 }
1663
1664 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1665         if len(t.GetField(FieldUserIconID).Data) == 4 {
1666                 cc.Icon = t.GetField(FieldUserIconID).Data[2:]
1667         } else {
1668                 cc.Icon = t.GetField(FieldUserIconID).Data
1669         }
1670         if cc.Authorize(accessAnyName) {
1671                 cc.UserName = t.GetField(FieldUserName).Data
1672         }
1673
1674         // the options field is only passed by the client versions > 1.2.3.
1675         options := t.GetField(FieldOptions).Data
1676         if options != nil {
1677                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1678                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
1679
1680                 flagBitmap.SetBit(flagBitmap, UserFlagRefusePM, optBitmap.Bit(refusePM))
1681                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1682
1683                 flagBitmap.SetBit(flagBitmap, UserFlagRefusePChat, optBitmap.Bit(refuseChat))
1684                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1685
1686                 // Check auto response
1687                 if optBitmap.Bit(autoResponse) == 1 {
1688                         cc.AutoReply = t.GetField(FieldAutomaticResponse).Data
1689                 } else {
1690                         cc.AutoReply = []byte{}
1691                 }
1692         }
1693
1694         for _, c := range sortedClients(cc.Server.Clients) {
1695                 res = append(res, *NewTransaction(
1696                         TranNotifyChangeUser,
1697                         c.ID,
1698                         NewField(FieldUserID, *cc.ID),
1699                         NewField(FieldUserIconID, cc.Icon),
1700                         NewField(FieldUserFlags, cc.Flags),
1701                         NewField(FieldUserName, cc.UserName),
1702                 ))
1703         }
1704
1705         return res, err
1706 }
1707
1708 // HandleKeepAlive responds to keepalive transactions with an empty reply
1709 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1710 // * HL 1.2.3 Client doesn't send keepalives
1711 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1712         res = append(res, cc.NewReply(t))
1713
1714         return res, err
1715 }
1716
1717 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1718         fullPath, err := readPath(
1719                 cc.Server.Config.FileRoot,
1720                 t.GetField(FieldFilePath).Data,
1721                 nil,
1722         )
1723         if err != nil {
1724                 return res, err
1725         }
1726
1727         var fp FilePath
1728         if t.GetField(FieldFilePath).Data != nil {
1729                 if _, err = fp.Write(t.GetField(FieldFilePath).Data); err != nil {
1730                         return res, err
1731                 }
1732         }
1733
1734         // Handle special case for drop box folders
1735         if fp.IsDropbox() && !cc.Authorize(accessViewDropBoxes) {
1736                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1737                 return res, err
1738         }
1739
1740         fileNames, err := getFileNameList(fullPath, cc.Server.Config.IgnoreFiles)
1741         if err != nil {
1742                 return res, err
1743         }
1744
1745         res = append(res, cc.NewReply(t, fileNames...))
1746
1747         return res, err
1748 }
1749
1750 // =================================
1751 //     Hotline private chat flow
1752 // =================================
1753 // 1. ClientA sends TranInviteNewChat to server with user ID to invite
1754 // 2. Server creates new ChatID
1755 // 3. Server sends TranInviteToChat to invitee
1756 // 4. Server replies to ClientA with new Chat ID
1757 //
1758 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1759 // If Accepted is clicked:
1760 // 1. ClientB sends TranJoinChat with FieldChatID
1761
1762 // HandleInviteNewChat invites users to new private chat
1763 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1764         if !cc.Authorize(accessOpenChat) {
1765                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1766                 return res, err
1767         }
1768
1769         // Client to Invite
1770         targetID := t.GetField(FieldUserID).Data
1771         newChatID := cc.Server.NewPrivateChat(cc)
1772
1773         // Check if target user has "Refuse private chat" flag
1774         binary.BigEndian.Uint16(targetID)
1775         targetClient := cc.Server.Clients[binary.BigEndian.Uint16(targetID)]
1776
1777         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(targetClient.Flags)))
1778         if flagBitmap.Bit(UserFlagRefusePChat) == 1 {
1779                 res = append(res,
1780                         *NewTransaction(
1781                                 TranServerMsg,
1782                                 cc.ID,
1783                                 NewField(FieldData, []byte(string(targetClient.UserName)+" does not accept private chats.")),
1784                                 NewField(FieldUserName, targetClient.UserName),
1785                                 NewField(FieldUserID, *targetClient.ID),
1786                                 NewField(FieldOptions, []byte{0, 2}),
1787                         ),
1788                 )
1789         } else {
1790                 res = append(res,
1791                         *NewTransaction(
1792                                 TranInviteToChat,
1793                                 &targetID,
1794                                 NewField(FieldChatID, newChatID),
1795                                 NewField(FieldUserName, cc.UserName),
1796                                 NewField(FieldUserID, *cc.ID),
1797                         ),
1798                 )
1799         }
1800
1801         res = append(res,
1802                 cc.NewReply(t,
1803                         NewField(FieldChatID, newChatID),
1804                         NewField(FieldUserName, cc.UserName),
1805                         NewField(FieldUserID, *cc.ID),
1806                         NewField(FieldUserIconID, cc.Icon),
1807                         NewField(FieldUserFlags, cc.Flags),
1808                 ),
1809         )
1810
1811         return res, err
1812 }
1813
1814 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1815         if !cc.Authorize(accessOpenChat) {
1816                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1817                 return res, err
1818         }
1819
1820         // Client to Invite
1821         targetID := t.GetField(FieldUserID).Data
1822         chatID := t.GetField(FieldChatID).Data
1823
1824         res = append(res,
1825                 *NewTransaction(
1826                         TranInviteToChat,
1827                         &targetID,
1828                         NewField(FieldChatID, chatID),
1829                         NewField(FieldUserName, cc.UserName),
1830                         NewField(FieldUserID, *cc.ID),
1831                 ),
1832         )
1833         res = append(res,
1834                 cc.NewReply(
1835                         t,
1836                         NewField(FieldChatID, chatID),
1837                         NewField(FieldUserName, cc.UserName),
1838                         NewField(FieldUserID, *cc.ID),
1839                         NewField(FieldUserIconID, cc.Icon),
1840                         NewField(FieldUserFlags, cc.Flags),
1841                 ),
1842         )
1843
1844         return res, err
1845 }
1846
1847 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1848         chatID := t.GetField(FieldChatID).Data
1849         chatInt := binary.BigEndian.Uint32(chatID)
1850
1851         privChat := cc.Server.PrivateChats[chatInt]
1852
1853         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1854
1855         for _, c := range sortedClients(privChat.ClientConn) {
1856                 res = append(res,
1857                         *NewTransaction(
1858                                 TranChatMsg,
1859                                 c.ID,
1860                                 NewField(FieldChatID, chatID),
1861                                 NewField(FieldData, resMsg),
1862                         ),
1863                 )
1864         }
1865
1866         return res, err
1867 }
1868
1869 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1870 // Fields used in the reply:
1871 // * 115        Chat subject
1872 // * 300        User name with info (Optional)
1873 // * 300        (more user names with info)
1874 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1875         chatID := t.GetField(FieldChatID).Data
1876         chatInt := binary.BigEndian.Uint32(chatID)
1877
1878         privChat := cc.Server.PrivateChats[chatInt]
1879
1880         // Send TranNotifyChatChangeUser to current members of the chat to inform of new user
1881         for _, c := range sortedClients(privChat.ClientConn) {
1882                 res = append(res,
1883                         *NewTransaction(
1884                                 TranNotifyChatChangeUser,
1885                                 c.ID,
1886                                 NewField(FieldChatID, chatID),
1887                                 NewField(FieldUserName, cc.UserName),
1888                                 NewField(FieldUserID, *cc.ID),
1889                                 NewField(FieldUserIconID, cc.Icon),
1890                                 NewField(FieldUserFlags, cc.Flags),
1891                         ),
1892                 )
1893         }
1894
1895         privChat.ClientConn[cc.uint16ID()] = cc
1896
1897         replyFields := []Field{NewField(FieldChatSubject, []byte(privChat.Subject))}
1898         for _, c := range sortedClients(privChat.ClientConn) {
1899                 user := User{
1900                         ID:    *c.ID,
1901                         Icon:  c.Icon,
1902                         Flags: c.Flags,
1903                         Name:  string(c.UserName),
1904                 }
1905
1906                 replyFields = append(replyFields, NewField(FieldUsernameWithInfo, user.Payload()))
1907         }
1908
1909         res = append(res, cc.NewReply(t, replyFields...))
1910         return res, err
1911 }
1912
1913 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1914 // Fields used in the request:
1915 //   - 114      FieldChatID
1916 //
1917 // Reply is not expected.
1918 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1919         chatID := t.GetField(FieldChatID).Data
1920         chatInt := binary.BigEndian.Uint32(chatID)
1921
1922         privChat, ok := cc.Server.PrivateChats[chatInt]
1923         if !ok {
1924                 return res, nil
1925         }
1926
1927         delete(privChat.ClientConn, cc.uint16ID())
1928
1929         // Notify members of the private chat that the user has left
1930         for _, c := range sortedClients(privChat.ClientConn) {
1931                 res = append(res,
1932                         *NewTransaction(
1933                                 TranNotifyChatDeleteUser,
1934                                 c.ID,
1935                                 NewField(FieldChatID, chatID),
1936                                 NewField(FieldUserID, *cc.ID),
1937                         ),
1938                 )
1939         }
1940
1941         return res, err
1942 }
1943
1944 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1945 // Fields used in the request:
1946 // * 114        Chat ID
1947 // * 115        Chat subject
1948 // Reply is not expected.
1949 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1950         chatID := t.GetField(FieldChatID).Data
1951         chatInt := binary.BigEndian.Uint32(chatID)
1952
1953         privChat := cc.Server.PrivateChats[chatInt]
1954         privChat.Subject = string(t.GetField(FieldChatSubject).Data)
1955
1956         for _, c := range sortedClients(privChat.ClientConn) {
1957                 res = append(res,
1958                         *NewTransaction(
1959                                 TranNotifyChatSubject,
1960                                 c.ID,
1961                                 NewField(FieldChatID, chatID),
1962                                 NewField(FieldChatSubject, t.GetField(FieldChatSubject).Data),
1963                         ),
1964                 )
1965         }
1966
1967         return res, err
1968 }
1969
1970 // HandleMakeAlias makes a file alias using the specified path.
1971 // Fields used in the request:
1972 // 201  File name
1973 // 202  File path
1974 // 212  File new path   Destination path
1975 //
1976 // Fields used in the reply:
1977 // None
1978 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1979         if !cc.Authorize(accessMakeAlias) {
1980                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1981                 return res, err
1982         }
1983         fileName := t.GetField(FieldFileName).Data
1984         filePath := t.GetField(FieldFilePath).Data
1985         fileNewPath := t.GetField(FieldFileNewPath).Data
1986
1987         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1988         if err != nil {
1989                 return res, err
1990         }
1991
1992         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1993         if err != nil {
1994                 return res, err
1995         }
1996
1997         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1998
1999         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
2000                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
2001                 return res, nil
2002         }
2003
2004         res = append(res, cc.NewReply(t))
2005         return res, err
2006 }
2007
2008 // HandleDownloadBanner handles requests for a new banner from the server
2009 // Fields used in the request:
2010 // None
2011 // Fields used in the reply:
2012 // 107  FieldRefNum                     Used later for transfer
2013 // 108  FieldTransferSize       Size of data to be downloaded
2014 func HandleDownloadBanner(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
2015         fi, err := cc.Server.FS.Stat(filepath.Join(cc.Server.ConfigDir, cc.Server.Config.BannerFile))
2016         if err != nil {
2017                 return res, err
2018         }
2019
2020         ft := cc.newFileTransfer(bannerDownload, []byte{}, []byte{}, make([]byte, 4))
2021
2022         binary.BigEndian.PutUint32(ft.TransferSize, uint32(fi.Size()))
2023
2024         res = append(res, cc.NewReply(t,
2025                 NewField(FieldRefNum, ft.refNum[:]),
2026                 NewField(FieldTransferSize, ft.TransferSize),
2027         ))
2028
2029         return res, err
2030 }