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

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "fmt"
   8         "gopkg.in/yaml.v3"
   9         "io/ioutil"
  10         "math/big"
  11         "os"
  12         "path"
  13         "path/filepath"
  14         "sort"
  15         "strings"
  16         "time"
  17 )
  18
  19 type TransactionType struct {
  20         Handler        func(*ClientConn, *Transaction) ([]Transaction, error) // function for handling the transaction type
  21         Name           string                                                 // Name of transaction as it will appear in logging
  22         RequiredFields []requiredField
  23 }
  24
  25 var TransactionHandlers = map[uint16]TransactionType{
  26         // Server initiated
  27         tranChatMsg: {
  28                 Name: "tranChatMsg",
  29         },
  30         // Server initiated
  31         tranNotifyChangeUser: {
  32                 Name: "tranNotifyChangeUser",
  33         },
  34         tranError: {
  35                 Name: "tranError",
  36         },
  37         tranShowAgreement: {
  38                 Name: "tranShowAgreement",
  39         },
  40         tranUserAccess: {
  41                 Name: "tranUserAccess",
  42         },
  43         tranNotifyDeleteUser: {
  44                 Name: "tranNotifyDeleteUser",
  45         },
  46         tranAgreed: {
  47                 Name:    "tranAgreed",
  48                 Handler: HandleTranAgreed,
  49         },
  50         tranChatSend: {
  51                 Name:    "tranChatSend",
  52                 Handler: HandleChatSend,
  53                 RequiredFields: []requiredField{
  54                         {
  55                                 ID:     fieldData,
  56                                 minLen: 0,
  57                         },
  58                 },
  59         },
  60         tranDelNewsArt: {
  61                 Name:    "tranDelNewsArt",
  62                 Handler: HandleDelNewsArt,
  63         },
  64         tranDelNewsItem: {
  65                 Name:    "tranDelNewsItem",
  66                 Handler: HandleDelNewsItem,
  67         },
  68         tranDeleteFile: {
  69                 Name:    "tranDeleteFile",
  70                 Handler: HandleDeleteFile,
  71         },
  72         tranDeleteUser: {
  73                 Name:    "tranDeleteUser",
  74                 Handler: HandleDeleteUser,
  75         },
  76         tranDisconnectUser: {
  77                 Name:    "tranDisconnectUser",
  78                 Handler: HandleDisconnectUser,
  79         },
  80         tranDownloadFile: {
  81                 Name:    "tranDownloadFile",
  82                 Handler: HandleDownloadFile,
  83         },
  84         tranDownloadFldr: {
  85                 Name:    "tranDownloadFldr",
  86                 Handler: HandleDownloadFolder,
  87         },
  88         tranGetClientInfoText: {
  89                 Name:    "tranGetClientInfoText",
  90                 Handler: HandleGetClientInfoText,
  91         },
  92         tranGetFileInfo: {
  93                 Name:    "tranGetFileInfo",
  94                 Handler: HandleGetFileInfo,
  95         },
  96         tranGetFileNameList: {
  97                 Name:    "tranGetFileNameList",
  98                 Handler: HandleGetFileNameList,
  99         },
 100         tranGetMsgs: {
 101                 Name:    "tranGetMsgs",
 102                 Handler: HandleGetMsgs,
 103         },
 104         tranGetNewsArtData: {
 105                 Name:    "tranGetNewsArtData",
 106                 Handler: HandleGetNewsArtData,
 107         },
 108         tranGetNewsArtNameList: {
 109                 Name:    "tranGetNewsArtNameList",
 110                 Handler: HandleGetNewsArtNameList,
 111         },
 112         tranGetNewsCatNameList: {
 113                 Name:    "tranGetNewsCatNameList",
 114                 Handler: HandleGetNewsCatNameList,
 115         },
 116         tranGetUser: {
 117                 Name:    "tranGetUser",
 118                 Handler: HandleGetUser,
 119         },
 120         tranGetUserNameList: {
 121                 Name:    "tranHandleGetUserNameList",
 122                 Handler: HandleGetUserNameList,
 123         },
 124         tranInviteNewChat: {
 125                 Name:    "tranInviteNewChat",
 126                 Handler: HandleInviteNewChat,
 127         },
 128         tranInviteToChat: {
 129                 Name:    "tranInviteToChat",
 130                 Handler: HandleInviteToChat,
 131         },
 132         tranJoinChat: {
 133                 Name:    "tranJoinChat",
 134                 Handler: HandleJoinChat,
 135         },
 136         tranKeepAlive: {
 137                 Name:    "tranKeepAlive",
 138                 Handler: HandleKeepAlive,
 139         },
 140         tranLeaveChat: {
 141                 Name:    "tranJoinChat",
 142                 Handler: HandleLeaveChat,
 143         },
 144         tranListUsers: {
 145                 Name:    "tranListUsers",
 146                 Handler: HandleListUsers,
 147         },
 148         tranMoveFile: {
 149                 Name:    "tranMoveFile",
 150                 Handler: HandleMoveFile,
 151         },
 152         tranNewFolder: {
 153                 Name:    "tranNewFolder",
 154                 Handler: HandleNewFolder,
 155         },
 156         tranNewNewsCat: {
 157                 Name:    "tranNewNewsCat",
 158                 Handler: HandleNewNewsCat,
 159         },
 160         tranNewNewsFldr: {
 161                 Name:    "tranNewNewsFldr",
 162                 Handler: HandleNewNewsFldr,
 163         },
 164         tranNewUser: {
 165                 Name:    "tranNewUser",
 166                 Handler: HandleNewUser,
 167         },
 168         tranUpdateUser: {
 169                 Name:    "tranUpdateUser",
 170                 Handler: HandleUpdateUser,
 171         },
 172         tranOldPostNews: {
 173                 Name:    "tranOldPostNews",
 174                 Handler: HandleTranOldPostNews,
 175         },
 176         tranPostNewsArt: {
 177                 Name:    "tranPostNewsArt",
 178                 Handler: HandlePostNewsArt,
 179         },
 180         tranRejectChatInvite: {
 181                 Name:    "tranRejectChatInvite",
 182                 Handler: HandleRejectChatInvite,
 183         },
 184         tranSendInstantMsg: {
 185                 Name:    "tranSendInstantMsg",
 186                 Handler: HandleSendInstantMsg,
 187                 RequiredFields: []requiredField{
 188                         {
 189                                 ID:     fieldData,
 190                                 minLen: 0,
 191                         },
 192                         {
 193                                 ID: fieldUserID,
 194                         },
 195                 },
 196         },
 197         tranSetChatSubject: {
 198                 Name:    "tranSetChatSubject",
 199                 Handler: HandleSetChatSubject,
 200         },
 201         tranMakeFileAlias: {
 202                 Name:    "tranMakeFileAlias",
 203                 Handler: HandleMakeAlias,
 204                 RequiredFields: []requiredField{
 205                         {ID: fieldFileName, minLen: 1},
 206                         {ID: fieldFilePath, minLen: 1},
 207                         {ID: fieldFileNewPath, minLen: 1},
 208                 },
 209         },
 210         tranSetClientUserInfo: {
 211                 Name:    "tranSetClientUserInfo",
 212                 Handler: HandleSetClientUserInfo,
 213         },
 214         tranSetFileInfo: {
 215                 Name:    "tranSetFileInfo",
 216                 Handler: HandleSetFileInfo,
 217         },
 218         tranSetUser: {
 219                 Name:    "tranSetUser",
 220                 Handler: HandleSetUser,
 221         },
 222         tranUploadFile: {
 223                 Name:    "tranUploadFile",
 224                 Handler: HandleUploadFile,
 225         },
 226         tranUploadFldr: {
 227                 Name:    "tranUploadFldr",
 228                 Handler: HandleUploadFolder,
 229         },
 230         tranUserBroadcast: {
 231                 Name:    "tranUserBroadcast",
 232                 Handler: HandleUserBroadcast,
 233         },
 234         tranDownloadBanner: {
 235                 Name:    "tranDownloadBanner",
 236                 Handler: HandleDownloadBanner,
 237         },
 238 }
 239
 240 func HandleChatSend(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 241         if !authorize(cc.Account.Access, accessSendChat) {
 242                 res = append(res, cc.NewErrReply(t, "You are not allowed to participate in chat."))
 243                 return res, err
 244         }
 245
 246         // Truncate long usernames
 247         trunc := fmt.Sprintf("%13s", cc.UserName)
 248         formattedMsg := fmt.Sprintf("\r%.14s:  %s", trunc, t.GetField(fieldData).Data)
 249
 250         // By holding the option key, Hotline chat allows users to send /me formatted messages like:
 251         // *** Halcyon does stuff
 252         // This is indicated by the presence of the optional field fieldChatOptions in the transaction payload
 253         if t.GetField(fieldChatOptions).Data != nil {
 254                 formattedMsg = fmt.Sprintf("\r*** %s %s", cc.UserName, t.GetField(fieldData).Data)
 255         }
 256
 257         chatID := t.GetField(fieldChatID).Data
 258         // a non-nil chatID indicates the message belongs to a private chat
 259         if chatID != nil {
 260                 chatInt := binary.BigEndian.Uint32(chatID)
 261                 privChat := cc.Server.PrivateChats[chatInt]
 262
 263                 clients := sortedClients(privChat.ClientConn)
 264
 265                 // send the message to all connected clients of the private chat
 266                 for _, c := range clients {
 267                         res = append(res, *NewTransaction(
 268                                 tranChatMsg,
 269                                 c.ID,
 270                                 NewField(fieldChatID, chatID),
 271                                 NewField(fieldData, []byte(formattedMsg)),
 272                         ))
 273                 }
 274                 return res, err
 275         }
 276
 277         for _, c := range sortedClients(cc.Server.Clients) {
 278                 // Filter out clients that do not have the read chat permission
 279                 if authorize(c.Account.Access, accessReadChat) {
 280                         res = append(res, *NewTransaction(tranChatMsg, c.ID, NewField(fieldData, []byte(formattedMsg))))
 281                 }
 282         }
 283
 284         return res, err
 285 }
 286
 287 // HandleSendInstantMsg sends instant message to the user on the current server.
 288 // Fields used in the request:
 289 //      103     User ID
 290 //      113     Options
 291 //              One of the following values:
 292 //              - User message (myOpt_UserMessage = 1)
 293 //              - Refuse message (myOpt_RefuseMessage = 2)
 294 //              - Refuse chat (myOpt_RefuseChat  = 3)
 295 //              - Automatic response (myOpt_AutomaticResponse = 4)"
 296 //      101     Data    Optional
 297 //      214     Quoting message Optional
 298 //
 299 // Fields used in the reply:
 300 // None
 301 func HandleSendInstantMsg(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 302         if !cc.Authorize(accessSendPrivMsg) {
 303                 res = append(res, cc.NewErrReply(t, "You are not allowed to send private messages."))
 304                 return res, err
 305         }
 306
 307         msg := t.GetField(fieldData)
 308         ID := t.GetField(fieldUserID)
 309
 310         reply := NewTransaction(
 311                 tranServerMsg,
 312                 &ID.Data,
 313                 NewField(fieldData, msg.Data),
 314                 NewField(fieldUserName, cc.UserName),
 315                 NewField(fieldUserID, *cc.ID),
 316                 NewField(fieldOptions, []byte{0, 1}),
 317         )
 318
 319         // Later versions of Hotline include the original message in the fieldQuotingMsg field so
 320         //  the receiving client can display both the received message and what it is in reply to
 321         if t.GetField(fieldQuotingMsg).Data != nil {
 322                 reply.Fields = append(reply.Fields, NewField(fieldQuotingMsg, t.GetField(fieldQuotingMsg).Data))
 323         }
 324
 325         res = append(res, *reply)
 326
 327         id, _ := byteToInt(ID.Data)
 328         otherClient, ok := cc.Server.Clients[uint16(id)]
 329         if !ok {
 330                 return res, errors.New("invalid client ID")
 331         }
 332
 333         // Respond with auto reply if other client has it enabled
 334         if len(otherClient.AutoReply) > 0 {
 335                 res = append(res,
 336                         *NewTransaction(
 337                                 tranServerMsg,
 338                                 cc.ID,
 339                                 NewField(fieldData, otherClient.AutoReply),
 340                                 NewField(fieldUserName, otherClient.UserName),
 341                                 NewField(fieldUserID, *otherClient.ID),
 342                                 NewField(fieldOptions, []byte{0, 1}),
 343                         ),
 344                 )
 345         }
 346
 347         res = append(res, cc.NewReply(t))
 348
 349         return res, err
 350 }
 351
 352 func HandleGetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 353         fileName := t.GetField(fieldFileName).Data
 354         filePath := t.GetField(fieldFilePath).Data
 355
 356         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 357         if err != nil {
 358                 return res, err
 359         }
 360
 361         fw, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 362         if err != nil {
 363                 return res, err
 364         }
 365
 366         res = append(res, cc.NewReply(t,
 367                 NewField(fieldFileName, []byte(fw.name)),
 368                 NewField(fieldFileTypeString, fw.ffo.FlatFileInformationFork.friendlyType()),
 369                 NewField(fieldFileCreatorString, fw.ffo.FlatFileInformationFork.friendlyCreator()),
 370                 NewField(fieldFileComment, fw.ffo.FlatFileInformationFork.Comment),
 371                 NewField(fieldFileType, fw.ffo.FlatFileInformationFork.TypeSignature),
 372                 NewField(fieldFileCreateDate, fw.ffo.FlatFileInformationFork.CreateDate),
 373                 NewField(fieldFileModifyDate, fw.ffo.FlatFileInformationFork.ModifyDate),
 374                 NewField(fieldFileSize, fw.totalSize()),
 375         ))
 376         return res, err
 377 }
 378
 379 // HandleSetFileInfo updates a file or folder name and/or comment from the Get Info window
 380 // Fields used in the request:
 381 // * 201        File name
 382 // * 202        File path       Optional
 383 // * 211        File new name   Optional
 384 // * 210        File comment    Optional
 385 // Fields used in the reply:    None
 386 func HandleSetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 387         fileName := t.GetField(fieldFileName).Data
 388         filePath := t.GetField(fieldFilePath).Data
 389
 390         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 391         if err != nil {
 392                 return res, err
 393         }
 394
 395         fi, err := cc.Server.FS.Stat(fullFilePath)
 396         if err != nil {
 397                 return res, err
 398         }
 399
 400         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 401         if err != nil {
 402                 return res, err
 403         }
 404         if t.GetField(fieldFileComment).Data != nil {
 405                 switch mode := fi.Mode(); {
 406                 case mode.IsDir():
 407                         if !authorize(cc.Account.Access, accessSetFolderComment) {
 408                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for folders."))
 409                                 return res, err
 410                         }
 411                 case mode.IsRegular():
 412                         if !authorize(cc.Account.Access, accessSetFileComment) {
 413                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for files."))
 414                                 return res, err
 415                         }
 416                 }
 417
 418                 if err := hlFile.ffo.FlatFileInformationFork.setComment(t.GetField(fieldFileComment).Data); err != nil {
 419                         return res, err
 420                 }
 421                 w, err := hlFile.infoForkWriter()
 422                 if err != nil {
 423                         return res, err
 424                 }
 425                 _, err = w.Write(hlFile.ffo.FlatFileInformationFork.MarshalBinary())
 426                 if err != nil {
 427                         return res, err
 428                 }
 429         }
 430
 431         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, t.GetField(fieldFileNewName).Data)
 432         if err != nil {
 433                 return nil, err
 434         }
 435
 436         fileNewName := t.GetField(fieldFileNewName).Data
 437
 438         if fileNewName != nil {
 439                 switch mode := fi.Mode(); {
 440                 case mode.IsDir():
 441                         if !authorize(cc.Account.Access, accessRenameFolder) {
 442                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename folders."))
 443                                 return res, err
 444                         }
 445                         err = os.Rename(fullFilePath, fullNewFilePath)
 446                         if os.IsNotExist(err) {
 447                                 res = append(res, cc.NewErrReply(t, "Cannot rename folder "+string(fileName)+" because it does not exist or cannot be found."))
 448                                 return res, err
 449                         }
 450                 case mode.IsRegular():
 451                         if !authorize(cc.Account.Access, accessRenameFile) {
 452                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename files."))
 453                                 return res, err
 454                         }
 455                         fileDir, err := readPath(cc.Server.Config.FileRoot, filePath, []byte{})
 456                         if err != nil {
 457                                 return nil, err
 458                         }
 459                         hlFile.name = string(fileNewName)
 460                         err = hlFile.move(fileDir)
 461                         if os.IsNotExist(err) {
 462                                 res = append(res, cc.NewErrReply(t, "Cannot rename file "+string(fileName)+" because it does not exist or cannot be found."))
 463                                 return res, err
 464                         }
 465                         if err != nil {
 466                                 panic(err)
 467                         }
 468                 }
 469         }
 470
 471         res = append(res, cc.NewReply(t))
 472         return res, err
 473 }
 474
 475 // HandleDeleteFile deletes a file or folder
 476 // Fields used in the request:
 477 // * 201        File name
 478 // * 202        File path
 479 // Fields used in the reply: none
 480 func HandleDeleteFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 481         fileName := t.GetField(fieldFileName).Data
 482         filePath := t.GetField(fieldFilePath).Data
 483
 484         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 485         if err != nil {
 486                 return res, err
 487         }
 488
 489         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 490         if err != nil {
 491                 return res, err
 492         }
 493
 494         fi, err := hlFile.dataFile()
 495         if err != nil {
 496                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+string(fileName)+" because it does not exist or cannot be found."))
 497                 return res, nil
 498         }
 499
 500         switch mode := fi.Mode(); {
 501         case mode.IsDir():
 502                 if !authorize(cc.Account.Access, accessDeleteFolder) {
 503                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete folders."))
 504                         return res, err
 505                 }
 506         case mode.IsRegular():
 507                 if !authorize(cc.Account.Access, accessDeleteFile) {
 508                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete files."))
 509                         return res, err
 510                 }
 511         }
 512
 513         if err := hlFile.delete(); err != nil {
 514                 return res, err
 515         }
 516
 517         res = append(res, cc.NewReply(t))
 518         return res, err
 519 }
 520
 521 // HandleMoveFile moves files or folders. Note: seemingly not documented
 522 func HandleMoveFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 523         fileName := string(t.GetField(fieldFileName).Data)
 524
 525         filePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
 526         if err != nil {
 527                 return res, err
 528         }
 529
 530         fileNewPath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFileNewPath).Data, nil)
 531         if err != nil {
 532                 return res, err
 533         }
 534
 535         cc.logger.Infow("Move file", "src", filePath+"/"+fileName, "dst", fileNewPath+"/"+fileName)
 536
 537         hlFile, err := newFileWrapper(cc.Server.FS, filePath, 0)
 538         if err != nil {
 539                 return res, err
 540         }
 541
 542         fi, err := hlFile.dataFile()
 543         if err != nil {
 544                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+fileName+" because it does not exist or cannot be found."))
 545                 return res, err
 546         }
 547         if err != nil {
 548                 return res, err
 549         }
 550         switch mode := fi.Mode(); {
 551         case mode.IsDir():
 552                 if !authorize(cc.Account.Access, accessMoveFolder) {
 553                         res = append(res, cc.NewErrReply(t, "You are not allowed to move folders."))
 554                         return res, err
 555                 }
 556         case mode.IsRegular():
 557                 if !authorize(cc.Account.Access, accessMoveFile) {
 558                         res = append(res, cc.NewErrReply(t, "You are not allowed to move files."))
 559                         return res, err
 560                 }
 561         }
 562         if err := hlFile.move(fileNewPath); err != nil {
 563                 return res, err
 564         }
 565         // TODO: handle other possible errors; e.g. fileWrapper delete fails due to fileWrapper permission issue
 566
 567         res = append(res, cc.NewReply(t))
 568         return res, err
 569 }
 570
 571 func HandleNewFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 572         if !authorize(cc.Account.Access, accessCreateFolder) {
 573                 res = append(res, cc.NewErrReply(t, "You are not allowed to create folders."))
 574                 return res, err
 575         }
 576         folderName := string(t.GetField(fieldFileName).Data)
 577
 578         folderName = path.Join("/", folderName)
 579
 580         var subPath string
 581
 582         // fieldFilePath is only present for nested paths
 583         if t.GetField(fieldFilePath).Data != nil {
 584                 var newFp FilePath
 585                 err := newFp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
 586                 if err != nil {
 587                         return nil, err
 588                 }
 589
 590                 for _, pathItem := range newFp.Items {
 591                         subPath = filepath.Join("/", subPath, string(pathItem.Name))
 592                 }
 593         }
 594         newFolderPath := path.Join(cc.Server.Config.FileRoot, subPath, folderName)
 595
 596         // TODO: check path and folder name lengths
 597
 598         if _, err := cc.Server.FS.Stat(newFolderPath); !os.IsNotExist(err) {
 599                 msg := fmt.Sprintf("Cannot create folder \"%s\" because there is already a file or folder with that name.", folderName)
 600                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 601         }
 602
 603         // TODO: check for disallowed characters to maintain compatibility for original client
 604
 605         if err := cc.Server.FS.Mkdir(newFolderPath, 0777); err != nil {
 606                 msg := fmt.Sprintf("Cannot create folder \"%s\" because an error occurred.", folderName)
 607                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 608         }
 609
 610         res = append(res, cc.NewReply(t))
 611         return res, err
 612 }
 613
 614 func HandleSetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 615         if !authorize(cc.Account.Access, accessModifyUser) {
 616                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 617                 return res, err
 618         }
 619
 620         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 621         userName := string(t.GetField(fieldUserName).Data)
 622
 623         newAccessLvl := t.GetField(fieldUserAccess).Data
 624
 625         account := cc.Server.Accounts[login]
 626         account.Access = &newAccessLvl
 627         account.Name = userName
 628
 629         // If the password field is cleared in the Hotline edit user UI, the SetUser transaction does
 630         // not include fieldUserPassword
 631         if t.GetField(fieldUserPassword).Data == nil {
 632                 account.Password = hashAndSalt([]byte(""))
 633         }
 634         if len(t.GetField(fieldUserPassword).Data) > 1 {
 635                 account.Password = hashAndSalt(t.GetField(fieldUserPassword).Data)
 636         }
 637
 638         out, err := yaml.Marshal(&account)
 639         if err != nil {
 640                 return res, err
 641         }
 642         if err := os.WriteFile(filepath.Join(cc.Server.ConfigDir, "Users", login+".yaml"), out, 0666); err != nil {
 643                 return res, err
 644         }
 645
 646         // Notify connected clients logged in as the user of the new access level
 647         for _, c := range cc.Server.Clients {
 648                 if c.Account.Login == login {
 649                         // Note: comment out these two lines to test server-side deny messages
 650                         newT := NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, newAccessLvl))
 651                         res = append(res, *newT)
 652
 653                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(c.Flags)))
 654                         if authorize(c.Account.Access, accessDisconUser) {
 655                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 1)
 656                         } else {
 657                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 0)
 658                         }
 659                         binary.BigEndian.PutUint16(c.Flags, uint16(flagBitmap.Int64()))
 660
 661                         c.Account.Access = account.Access
 662
 663                         cc.sendAll(
 664                                 tranNotifyChangeUser,
 665                                 NewField(fieldUserID, *c.ID),
 666                                 NewField(fieldUserFlags, c.Flags),
 667                                 NewField(fieldUserName, c.UserName),
 668                                 NewField(fieldUserIconID, c.Icon),
 669                         )
 670                 }
 671         }
 672
 673         res = append(res, cc.NewReply(t))
 674         return res, err
 675 }
 676
 677 func HandleGetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 678         if !authorize(cc.Account.Access, accessOpenUser) {
 679                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 680                 return res, err
 681         }
 682
 683         account := cc.Server.Accounts[string(t.GetField(fieldUserLogin).Data)]
 684         if account == nil {
 685                 res = append(res, cc.NewErrReply(t, "Account does not exist."))
 686                 return res, err
 687         }
 688
 689         res = append(res, cc.NewReply(t,
 690                 NewField(fieldUserName, []byte(account.Name)),
 691                 NewField(fieldUserLogin, negateString(t.GetField(fieldUserLogin).Data)),
 692                 NewField(fieldUserPassword, []byte(account.Password)),
 693                 NewField(fieldUserAccess, *account.Access),
 694         ))
 695         return res, err
 696 }
 697
 698 func HandleListUsers(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 699         if !authorize(cc.Account.Access, accessOpenUser) {
 700                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 701                 return res, err
 702         }
 703
 704         var userFields []Field
 705         for _, acc := range cc.Server.Accounts {
 706                 b := make([]byte, 0, 100)
 707                 n, err := acc.Read(b)
 708                 if err != nil {
 709                         return res, err
 710                 }
 711
 712                 userFields = append(userFields, NewField(fieldData, b[:n]))
 713         }
 714
 715         res = append(res, cc.NewReply(t, userFields...))
 716         return res, err
 717 }
 718
 719 // HandleUpdateUser is used by the v1.5+ multi-user editor to perform account editing for multiple users at a time.
 720 // An update can be a mix of these actions:
 721 // * Create user
 722 // * Delete user
 723 // * Modify user (including renaming the account login)
 724 //
 725 // The Transaction sent by the client includes one data field per user that was modified.  This data field in turn
 726 // contains another data field encoded in its payload with a varying number of sub fields depending on which action is
 727 // performed.  This seems to be the only place in the Hotline protocol where a data field contains another data field.
 728 func HandleUpdateUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 729         for _, field := range t.Fields {
 730                 subFields, err := ReadFields(field.Data[0:2], field.Data[2:])
 731                 if err != nil {
 732                         return res, err
 733                 }
 734
 735                 if len(subFields) == 1 {
 736                         login := DecodeUserString(getField(fieldData, &subFields).Data)
 737                         cc.logger.Infow("DeleteUser", "login", login)
 738
 739                         if !authorize(cc.Account.Access, accessDeleteUser) {
 740                                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 741                                 return res, err
 742                         }
 743
 744                         if err := cc.Server.DeleteUser(login); err != nil {
 745                                 return res, err
 746                         }
 747                         continue
 748                 }
 749
 750                 login := DecodeUserString(getField(fieldUserLogin, &subFields).Data)
 751
 752                 // check if the login dataFile; if so, we know we are updating an existing user
 753                 if acc, ok := cc.Server.Accounts[login]; ok {
 754                         cc.logger.Infow("UpdateUser", "login", login)
 755
 756                         // account dataFile, so this is an update action
 757                         if !authorize(cc.Account.Access, accessModifyUser) {
 758                                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 759                                 return res, err
 760                         }
 761
 762                         if getField(fieldUserPassword, &subFields) != nil {
 763                                 newPass := getField(fieldUserPassword, &subFields).Data
 764                                 acc.Password = hashAndSalt(newPass)
 765                         } else {
 766                                 acc.Password = hashAndSalt([]byte(""))
 767                         }
 768
 769                         if getField(fieldUserAccess, &subFields) != nil {
 770                                 acc.Access = &getField(fieldUserAccess, &subFields).Data
 771                         }
 772
 773                         err = cc.Server.UpdateUser(
 774                                 DecodeUserString(getField(fieldData, &subFields).Data),
 775                                 DecodeUserString(getField(fieldUserLogin, &subFields).Data),
 776                                 string(getField(fieldUserName, &subFields).Data),
 777                                 acc.Password,
 778                                 *acc.Access,
 779                         )
 780                         if err != nil {
 781                                 return res, err
 782                         }
 783                 } else {
 784                         cc.logger.Infow("CreateUser", "login", login)
 785
 786                         if !authorize(cc.Account.Access, accessCreateUser) {
 787                                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 788                                 return res, err
 789                         }
 790
 791                         err := cc.Server.NewUser(
 792                                 login,
 793                                 string(getField(fieldUserName, &subFields).Data),
 794                                 string(getField(fieldUserPassword, &subFields).Data),
 795                                 getField(fieldUserAccess, &subFields).Data,
 796                         )
 797                         if err != nil {
 798                                 return []Transaction{}, err
 799                         }
 800                 }
 801         }
 802
 803         res = append(res, cc.NewReply(t))
 804         return res, err
 805 }
 806
 807 // HandleNewUser creates a new user account
 808 func HandleNewUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 809         if !authorize(cc.Account.Access, accessCreateUser) {
 810                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 811                 return res, err
 812         }
 813
 814         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 815
 816         // If the account already dataFile, reply with an error
 817         if _, ok := cc.Server.Accounts[login]; ok {
 818                 res = append(res, cc.NewErrReply(t, "Cannot create account "+login+" because there is already an account with that login."))
 819                 return res, err
 820         }
 821
 822         if err := cc.Server.NewUser(
 823                 login,
 824                 string(t.GetField(fieldUserName).Data),
 825                 string(t.GetField(fieldUserPassword).Data),
 826                 t.GetField(fieldUserAccess).Data,
 827         ); err != nil {
 828                 return []Transaction{}, err
 829         }
 830
 831         res = append(res, cc.NewReply(t))
 832         return res, err
 833 }
 834
 835 func HandleDeleteUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 836         if !authorize(cc.Account.Access, accessDeleteUser) {
 837                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 838                 return res, err
 839         }
 840
 841         // TODO: Handle case where account doesn't exist; e.g. delete race condition
 842         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 843
 844         if err := cc.Server.DeleteUser(login); err != nil {
 845                 return res, err
 846         }
 847
 848         res = append(res, cc.NewReply(t))
 849         return res, err
 850 }
 851
 852 // HandleUserBroadcast sends an Administrator Message to all connected clients of the server
 853 func HandleUserBroadcast(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 854         if !authorize(cc.Account.Access, accessBroadcast) {
 855                 res = append(res, cc.NewErrReply(t, "You are not allowed to send broadcast messages."))
 856                 return res, err
 857         }
 858
 859         cc.sendAll(
 860                 tranServerMsg,
 861                 NewField(fieldData, t.GetField(tranGetMsgs).Data),
 862                 NewField(fieldChatOptions, []byte{0}),
 863         )
 864
 865         res = append(res, cc.NewReply(t))
 866         return res, err
 867 }
 868
 869 func byteToInt(bytes []byte) (int, error) {
 870         switch len(bytes) {
 871         case 2:
 872                 return int(binary.BigEndian.Uint16(bytes)), nil
 873         case 4:
 874                 return int(binary.BigEndian.Uint32(bytes)), nil
 875         }
 876
 877         return 0, errors.New("unknown byte length")
 878 }
 879
 880 // HandleGetClientInfoText returns user information for the specific user.
 881 //
 882 // Fields used in the request:
 883 // 103  User ID
 884 //
 885 // Fields used in the reply:
 886 // 102  User name
 887 // 101  Data            User info text string
 888 func HandleGetClientInfoText(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 889         if !authorize(cc.Account.Access, accessGetClientInfo) {
 890                 res = append(res, cc.NewErrReply(t, "You are not allowed to get client info."))
 891                 return res, err
 892         }
 893
 894         clientID, _ := byteToInt(t.GetField(fieldUserID).Data)
 895
 896         clientConn := cc.Server.Clients[uint16(clientID)]
 897         if clientConn == nil {
 898                 return append(res, cc.NewErrReply(t, "User not found.")), err
 899         }
 900
 901         res = append(res, cc.NewReply(t,
 902                 NewField(fieldData, []byte(clientConn.String())),
 903                 NewField(fieldUserName, clientConn.UserName),
 904         ))
 905         return res, err
 906 }
 907
 908 func HandleGetUserNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 909         res = append(res, cc.NewReply(t, cc.Server.connectedUsers()...))
 910
 911         return res, err
 912 }
 913
 914 func HandleTranAgreed(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 915         cc.Agreed = true
 916
 917         if t.GetField(fieldUserName).Data != nil {
 918                 if cc.Authorize(accessAnyName) {
 919                         cc.UserName = t.GetField(fieldUserName).Data
 920                 } else {
 921                         cc.UserName = []byte(cc.Account.Name)
 922                 }
 923         }
 924
 925         cc.Icon = t.GetField(fieldUserIconID).Data
 926
 927         cc.logger = cc.logger.With("name", string(cc.UserName))
 928         cc.logger.Infow("Login successful", "clientVersion", fmt.Sprintf("%x", cc.Version))
 929
 930         options := t.GetField(fieldOptions).Data
 931         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 932
 933         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
 934
 935         // Check refuse private PM option
 936         if optBitmap.Bit(refusePM) == 1 {
 937                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, 1)
 938                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 939         }
 940
 941         // Check refuse private chat option
 942         if optBitmap.Bit(refuseChat) == 1 {
 943                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, 1)
 944                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 945         }
 946
 947         // Check auto response
 948         if optBitmap.Bit(autoResponse) == 1 {
 949                 cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
 950         } else {
 951                 cc.AutoReply = []byte{}
 952         }
 953
 954         trans := cc.notifyOthers(
 955                 *NewTransaction(
 956                         tranNotifyChangeUser, nil,
 957                         NewField(fieldUserName, cc.UserName),
 958                         NewField(fieldUserID, *cc.ID),
 959                         NewField(fieldUserIconID, cc.Icon),
 960                         NewField(fieldUserFlags, cc.Flags),
 961                 ),
 962         )
 963         res = append(res, trans...)
 964
 965         if cc.Server.Config.BannerFile != "" {
 966                 res = append(res, *NewTransaction(tranServerBanner, cc.ID, NewField(fieldBannerType, []byte("JPEG"))))
 967         }
 968
 969         res = append(res, cc.NewReply(t))
 970
 971         return res, err
 972 }
 973
 974 const defaultNewsDateFormat = "Jan02 15:04" // Jun23 20:49
 975 //  "Mon, 02 Jan 2006 15:04:05 MST"
 976
 977 const defaultNewsTemplate = `From %s (%s):
 978
 979 %s
 980
 981 __________________________________________________________`
 982
 983 // HandleTranOldPostNews updates the flat news
 984 // Fields used in this request:
 985 // 101  Data
 986 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 987         if !authorize(cc.Account.Access, accessNewsPostArt) {
 988                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
 989                 return res, err
 990         }
 991
 992         cc.Server.flatNewsMux.Lock()
 993         defer cc.Server.flatNewsMux.Unlock()
 994
 995         newsDateTemplate := defaultNewsDateFormat
 996         if cc.Server.Config.NewsDateFormat != "" {
 997                 newsDateTemplate = cc.Server.Config.NewsDateFormat
 998         }
 999
1000         newsTemplate := defaultNewsTemplate
1001         if cc.Server.Config.NewsDelimiter != "" {
1002                 newsTemplate = cc.Server.Config.NewsDelimiter
1003         }
1004
1005         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(fieldData).Data)
1006         newsPost = strings.Replace(newsPost, "\n", "\r", -1)
1007
1008         // update news in memory
1009         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
1010
1011         // update news on disk
1012         if err := ioutil.WriteFile(cc.Server.ConfigDir+"MessageBoard.txt", cc.Server.FlatNews, 0644); err != nil {
1013                 return res, err
1014         }
1015
1016         // Notify all clients of updated news
1017         cc.sendAll(
1018                 tranNewMsg,
1019                 NewField(fieldData, []byte(newsPost)),
1020         )
1021
1022         res = append(res, cc.NewReply(t))
1023         return res, err
1024 }
1025
1026 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1027         if !authorize(cc.Account.Access, accessDisconUser) {
1028                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1029                 return res, err
1030         }
1031
1032         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(fieldUserID).Data)]
1033
1034         if authorize(clientConn.Account.Access, accessCannotBeDiscon) {
1035                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1036                 return res, err
1037         }
1038
1039         // If fieldOptions is set, then the client IP is banned in addition to disconnected.
1040         // 00 01 = temporary ban
1041         // 00 02 = permanent ban
1042         if t.GetField(fieldOptions).Data != nil {
1043                 switch t.GetField(fieldOptions).Data[1] {
1044                 case 1:
1045                         // send message: "You are temporarily banned on this server"
1046                         cc.logger.Infow("Disconnect & temporarily ban " + string(clientConn.UserName))
1047
1048                         res = append(res, *NewTransaction(
1049                                 tranServerMsg,
1050                                 clientConn.ID,
1051                                 NewField(fieldData, []byte("You are temporarily banned on this server")),
1052                                 NewField(fieldChatOptions, []byte{0, 0}),
1053                         ))
1054
1055                         banUntil := time.Now().Add(tempBanDuration)
1056                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = &banUntil
1057                         cc.Server.writeBanList()
1058                 case 2:
1059                         // send message: "You are permanently banned on this server"
1060                         cc.logger.Infow("Disconnect & ban " + string(clientConn.UserName))
1061
1062                         res = append(res, *NewTransaction(
1063                                 tranServerMsg,
1064                                 clientConn.ID,
1065                                 NewField(fieldData, []byte("You are permanently banned on this server")),
1066                                 NewField(fieldChatOptions, []byte{0, 0}),
1067                         ))
1068
1069                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = nil
1070                         cc.Server.writeBanList()
1071                 }
1072         }
1073
1074         // TODO: remove this awful hack
1075         go func() {
1076                 time.Sleep(1 * time.Second)
1077                 clientConn.Disconnect()
1078         }()
1079
1080         return append(res, cc.NewReply(t)), err
1081 }
1082
1083 // HandleGetNewsCatNameList returns a list of news categories for a path
1084 // Fields used in the request:
1085 // 325  News path       (Optional)
1086 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1087         if !authorize(cc.Account.Access, accessNewsReadArt) {
1088                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1089                 return res, err
1090         }
1091
1092         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1093         cats := cc.Server.GetNewsCatByPath(pathStrs)
1094
1095         // To store the keys in slice in sorted order
1096         keys := make([]string, len(cats))
1097         i := 0
1098         for k := range cats {
1099                 keys[i] = k
1100                 i++
1101         }
1102         sort.Strings(keys)
1103
1104         var fieldData []Field
1105         for _, k := range keys {
1106                 cat := cats[k]
1107                 b, _ := cat.MarshalBinary()
1108                 fieldData = append(fieldData, NewField(
1109                         fieldNewsCatListData15,
1110                         b,
1111                 ))
1112         }
1113
1114         res = append(res, cc.NewReply(t, fieldData...))
1115         return res, err
1116 }
1117
1118 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1119         if !authorize(cc.Account.Access, accessNewsCreateCat) {
1120                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1121                 return res, err
1122         }
1123
1124         name := string(t.GetField(fieldNewsCatName).Data)
1125         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1126
1127         cats := cc.Server.GetNewsCatByPath(pathStrs)
1128         cats[name] = NewsCategoryListData15{
1129                 Name:     name,
1130                 Type:     []byte{0, 3},
1131                 Articles: map[uint32]*NewsArtData{},
1132                 SubCats:  make(map[string]NewsCategoryListData15),
1133         }
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 // 322  News category name
1144 // 325  News path
1145 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1146         if !authorize(cc.Account.Access, accessNewsCreateFldr) {
1147                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1148                 return res, err
1149         }
1150
1151         name := string(t.GetField(fieldFileName).Data)
1152         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1153
1154         cc.logger.Infof("Creating new news folder %s", name)
1155
1156         cats := cc.Server.GetNewsCatByPath(pathStrs)
1157         cats[name] = NewsCategoryListData15{
1158                 Name:     name,
1159                 Type:     []byte{0, 2},
1160                 Articles: map[uint32]*NewsArtData{},
1161                 SubCats:  make(map[string]NewsCategoryListData15),
1162         }
1163         if err := cc.Server.writeThreadedNews(); err != nil {
1164                 return res, err
1165         }
1166         res = append(res, cc.NewReply(t))
1167         return res, err
1168 }
1169
1170 // Fields used in the request:
1171 // 325  News path       Optional
1172 //
1173 // Reply fields:
1174 // 321  News article list data  Optional
1175 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1176         if !authorize(cc.Account.Access, accessNewsReadArt) {
1177                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1178                 return res, err
1179         }
1180         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1181
1182         var cat NewsCategoryListData15
1183         cats := cc.Server.ThreadedNews.Categories
1184
1185         for _, fp := range pathStrs {
1186                 cat = cats[fp]
1187                 cats = cats[fp].SubCats
1188         }
1189
1190         nald := cat.GetNewsArtListData()
1191
1192         res = append(res, cc.NewReply(t, NewField(fieldNewsArtListData, nald.Payload())))
1193         return res, err
1194 }
1195
1196 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1197         if !authorize(cc.Account.Access, accessNewsReadArt) {
1198                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1199                 return res, err
1200         }
1201
1202         // Request fields
1203         // 325  News fp
1204         // 326  News article ID
1205         // 327  News article data flavor
1206
1207         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1208
1209         var cat NewsCategoryListData15
1210         cats := cc.Server.ThreadedNews.Categories
1211
1212         for _, fp := range pathStrs {
1213                 cat = cats[fp]
1214                 cats = cats[fp].SubCats
1215         }
1216         newsArtID := t.GetField(fieldNewsArtID).Data
1217
1218         convertedArtID := binary.BigEndian.Uint16(newsArtID)
1219
1220         art := cat.Articles[uint32(convertedArtID)]
1221         if art == nil {
1222                 res = append(res, cc.NewReply(t))
1223                 return res, err
1224         }
1225
1226         // Reply fields
1227         // 328  News article title
1228         // 329  News article poster
1229         // 330  News article date
1230         // 331  Previous article ID
1231         // 332  Next article ID
1232         // 335  Parent article ID
1233         // 336  First child article ID
1234         // 327  News article data flavor        "Should be “text/plain”
1235         // 333  News article data       Optional (if data flavor is “text/plain”)
1236
1237         res = append(res, cc.NewReply(t,
1238                 NewField(fieldNewsArtTitle, []byte(art.Title)),
1239                 NewField(fieldNewsArtPoster, []byte(art.Poster)),
1240                 NewField(fieldNewsArtDate, art.Date),
1241                 NewField(fieldNewsArtPrevArt, art.PrevArt),
1242                 NewField(fieldNewsArtNextArt, art.NextArt),
1243                 NewField(fieldNewsArtParentArt, art.ParentArt),
1244                 NewField(fieldNewsArt1stChildArt, art.FirstChildArt),
1245                 NewField(fieldNewsArtDataFlav, []byte("text/plain")),
1246                 NewField(fieldNewsArtData, []byte(art.Data)),
1247         ))
1248         return res, err
1249 }
1250
1251 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1252         // Has multiple access flags: News Delete Folder (37) or News Delete Category (35)
1253         // TODO: Implement
1254
1255         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1256
1257         // TODO: determine if path is a Folder (Bundle) or Category and check for permission
1258
1259         cc.logger.Infof("DelNewsItem %v", pathStrs)
1260
1261         cats := cc.Server.ThreadedNews.Categories
1262
1263         delName := pathStrs[len(pathStrs)-1]
1264         if len(pathStrs) > 1 {
1265                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1266                         cats = cats[fp].SubCats
1267                 }
1268         }
1269
1270         delete(cats, delName)
1271
1272         err = cc.Server.writeThreadedNews()
1273         if err != nil {
1274                 return res, err
1275         }
1276
1277         // Reply params: none
1278         res = append(res, cc.NewReply(t))
1279
1280         return res, err
1281 }
1282
1283 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1284         if !authorize(cc.Account.Access, accessNewsDeleteArt) {
1285                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1286                 return res, err
1287         }
1288
1289         // Request Fields
1290         // 325  News path
1291         // 326  News article ID
1292         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1293         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1294         ID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1295
1296         // TODO: Delete recursive
1297         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1298
1299         catName := pathStrs[len(pathStrs)-1]
1300         cat := cats[catName]
1301
1302         delete(cat.Articles, uint32(ID))
1303
1304         cats[catName] = cat
1305         if err := cc.Server.writeThreadedNews(); err != nil {
1306                 return res, err
1307         }
1308
1309         res = append(res, cc.NewReply(t))
1310         return res, err
1311 }
1312
1313 // Request fields
1314 // 325  News path
1315 // 326  News article ID                                                 ID of the parent article?
1316 // 328  News article title
1317 // 334  News article flags
1318 // 327  News article data flavor                Currently “text/plain”
1319 // 333  News article data
1320 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1321         if !authorize(cc.Account.Access, accessNewsPostArt) {
1322                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1323                 return res, err
1324         }
1325
1326         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1327         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1328
1329         catName := pathStrs[len(pathStrs)-1]
1330         cat := cats[catName]
1331
1332         newArt := NewsArtData{
1333                 Title:         string(t.GetField(fieldNewsArtTitle).Data),
1334                 Poster:        string(cc.UserName),
1335                 Date:          toHotlineTime(time.Now()),
1336                 PrevArt:       []byte{0, 0, 0, 0},
1337                 NextArt:       []byte{0, 0, 0, 0},
1338                 ParentArt:     append([]byte{0, 0}, t.GetField(fieldNewsArtID).Data...),
1339                 FirstChildArt: []byte{0, 0, 0, 0},
1340                 DataFlav:      []byte("text/plain"),
1341                 Data:          string(t.GetField(fieldNewsArtData).Data),
1342         }
1343
1344         var keys []int
1345         for k := range cat.Articles {
1346                 keys = append(keys, int(k))
1347         }
1348
1349         nextID := uint32(1)
1350         if len(keys) > 0 {
1351                 sort.Ints(keys)
1352                 prevID := uint32(keys[len(keys)-1])
1353                 nextID = prevID + 1
1354
1355                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1356
1357                 // Set next article ID
1358                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1359         }
1360
1361         // Update parent article with first child reply
1362         parentID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1363         if parentID != 0 {
1364                 parentArt := cat.Articles[uint32(parentID)]
1365
1366                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1367                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1368                 }
1369         }
1370
1371         cat.Articles[nextID] = &newArt
1372
1373         cats[catName] = cat
1374         if err := cc.Server.writeThreadedNews(); err != nil {
1375                 return res, err
1376         }
1377
1378         res = append(res, cc.NewReply(t))
1379         return res, err
1380 }
1381
1382 // HandleGetMsgs returns the flat news data
1383 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1384         if !authorize(cc.Account.Access, accessNewsReadArt) {
1385                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1386                 return res, err
1387         }
1388
1389         res = append(res, cc.NewReply(t, NewField(fieldData, cc.Server.FlatNews)))
1390
1391         return res, err
1392 }
1393
1394 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1395         if !authorize(cc.Account.Access, accessDownloadFile) {
1396                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1397                 return res, err
1398         }
1399
1400         fileName := t.GetField(fieldFileName).Data
1401         filePath := t.GetField(fieldFilePath).Data
1402         resumeData := t.GetField(fieldFileResumeData).Data
1403
1404         var dataOffset int64
1405         var frd FileResumeData
1406         if resumeData != nil {
1407                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1408                         return res, err
1409                 }
1410                 // TODO: handle rsrc fork offset
1411                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1412         }
1413
1414         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1415         if err != nil {
1416                 return res, err
1417         }
1418
1419         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1420         if err != nil {
1421                 return res, err
1422         }
1423
1424         xferSize := hlFile.ffo.TransferSize(0)
1425
1426         ft := cc.newFileTransfer(FileDownload, fileName, filePath, xferSize)
1427
1428         // TODO: refactor to remove this
1429         if resumeData != nil {
1430                 var frd FileResumeData
1431                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1432                         return res, err
1433                 }
1434                 ft.fileResumeData = &frd
1435         }
1436
1437         // Optional field for when a HL v1.5+ client requests file preview
1438         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1439         // The value will always be 2
1440         if t.GetField(fieldFileTransferOptions).Data != nil {
1441                 ft.options = t.GetField(fieldFileTransferOptions).Data
1442                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1443         }
1444
1445         res = append(res, cc.NewReply(t,
1446                 NewField(fieldRefNum, ft.refNum[:]),
1447                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1448                 NewField(fieldTransferSize, xferSize),
1449                 NewField(fieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1450         ))
1451
1452         return res, err
1453 }
1454
1455 // Download all files from the specified folder and sub-folders
1456 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1457         if !authorize(cc.Account.Access, accessDownloadFile) {
1458                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1459                 return res, err
1460         }
1461
1462         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
1463         if err != nil {
1464                 return res, err
1465         }
1466
1467         transferSize, err := CalcTotalSize(fullFilePath)
1468         if err != nil {
1469                 return res, err
1470         }
1471         itemCount, err := CalcItemCount(fullFilePath)
1472         if err != nil {
1473                 return res, err
1474         }
1475
1476         fileTransfer := cc.newFileTransfer(FolderDownload, t.GetField(fieldFileName).Data, t.GetField(fieldFilePath).Data, transferSize)
1477
1478         var fp FilePath
1479         err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data)
1480         if err != nil {
1481                 return res, err
1482         }
1483
1484         res = append(res, cc.NewReply(t,
1485                 NewField(fieldRefNum, fileTransfer.ReferenceNumber),
1486                 NewField(fieldTransferSize, transferSize),
1487                 NewField(fieldFolderItemCount, itemCount),
1488                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1489         ))
1490         return res, err
1491 }
1492
1493 // Upload all files from the local folder and its subfolders to the specified path on the server
1494 // Fields used in the request
1495 // 201  File name
1496 // 202  File path
1497 // 108  transfer size   Total size of all items in the folder
1498 // 220  Folder item count
1499 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1500 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
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 := cc.newFileTransfer(FolderUpload,
1517                 t.GetField(fieldFileName).Data,
1518                 t.GetField(fieldFilePath).Data,
1519                 t.GetField(fieldTransferSize).Data,
1520         )
1521
1522         fileTransfer.FolderItemCount = t.GetField(fieldFolderItemCount).Data
1523
1524         res = append(res, cc.NewReply(t, NewField(fieldRefNum, fileTransfer.ReferenceNumber)))
1525         return res, err
1526 }
1527
1528 // HandleUploadFile
1529 // Fields used in the request:
1530 // 201  File name
1531 // 202  File path
1532 // 204  File transfer options   "Optional
1533 // Used only to resume download, currently has value 2"
1534 // 108  File transfer size      "Optional used if download is not resumed"
1535 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1536         if !authorize(cc.Account.Access, accessUploadFile) {
1537                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1538                 return res, err
1539         }
1540
1541         fileName := t.GetField(fieldFileName).Data
1542         filePath := t.GetField(fieldFilePath).Data
1543         transferOptions := t.GetField(fieldFileTransferOptions).Data
1544         transferSize := t.GetField(fieldTransferSize).Data // not sent for resume
1545
1546         var fp FilePath
1547         if filePath != nil {
1548                 if err = fp.UnmarshalBinary(filePath); err != nil {
1549                         return res, err
1550                 }
1551         }
1552
1553         // Handle special cases for Upload and Drop Box folders
1554         if !authorize(cc.Account.Access, accessUploadAnywhere) {
1555                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1556                         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))))
1557                         return res, err
1558                 }
1559         }
1560         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1561         if err != nil {
1562                 return res, err
1563         }
1564
1565         if _, err := cc.Server.FS.Stat(fullFilePath); err == nil {
1566                 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))))
1567                 return res, err
1568         }
1569
1570         ft := cc.newFileTransfer(FileUpload, fileName, filePath, transferSize)
1571
1572         replyT := cc.NewReply(t, NewField(fieldRefNum, ft.ReferenceNumber))
1573
1574         // client has requested to resume a partially transferred file
1575         if transferOptions != nil {
1576
1577                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1578                 if err != nil {
1579                         return res, err
1580                 }
1581
1582                 offset := make([]byte, 4)
1583                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1584
1585                 fileResumeData := NewFileResumeData([]ForkInfoList{
1586                         *NewForkInfoList(offset),
1587                 })
1588
1589                 b, _ := fileResumeData.BinaryMarshal()
1590
1591                 ft.TransferSize = offset
1592
1593                 replyT.Fields = append(replyT.Fields, NewField(fieldFileResumeData, b))
1594         }
1595
1596         res = append(res, replyT)
1597         return res, err
1598 }
1599
1600 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1601         if len(t.GetField(fieldUserIconID).Data) == 4 {
1602                 cc.Icon = t.GetField(fieldUserIconID).Data[2:]
1603         } else {
1604                 cc.Icon = t.GetField(fieldUserIconID).Data
1605         }
1606         if cc.Authorize(accessAnyName) {
1607                 cc.UserName = t.GetField(fieldUserName).Data
1608         }
1609
1610         // the options field is only passed by the client versions > 1.2.3.
1611         options := t.GetField(fieldOptions).Data
1612         if options != nil {
1613                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1614                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
1615
1616                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, optBitmap.Bit(refusePM))
1617                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1618
1619                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, optBitmap.Bit(refuseChat))
1620                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1621
1622                 // Check auto response
1623                 if optBitmap.Bit(autoResponse) == 1 {
1624                         cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
1625                 } else {
1626                         cc.AutoReply = []byte{}
1627                 }
1628         }
1629
1630         for _, c := range sortedClients(cc.Server.Clients) {
1631                 res = append(res, *NewTransaction(
1632                         tranNotifyChangeUser,
1633                         c.ID,
1634                         NewField(fieldUserID, *cc.ID),
1635                         NewField(fieldUserIconID, cc.Icon),
1636                         NewField(fieldUserFlags, cc.Flags),
1637                         NewField(fieldUserName, cc.UserName),
1638                 ))
1639         }
1640
1641         return res, err
1642 }
1643
1644 // HandleKeepAlive responds to keepalive transactions with an empty reply
1645 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1646 // * HL 1.2.3 Client doesn't send keepalives
1647 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1648         res = append(res, cc.NewReply(t))
1649
1650         return res, err
1651 }
1652
1653 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1654         fullPath, err := readPath(
1655                 cc.Server.Config.FileRoot,
1656                 t.GetField(fieldFilePath).Data,
1657                 nil,
1658         )
1659         if err != nil {
1660                 return res, err
1661         }
1662
1663         var fp FilePath
1664         if t.GetField(fieldFilePath).Data != nil {
1665                 if err = fp.UnmarshalBinary(t.GetField(fieldFilePath).Data); err != nil {
1666                         return res, err
1667                 }
1668         }
1669
1670         // Handle special case for drop box folders
1671         if fp.IsDropbox() && !authorize(cc.Account.Access, accessViewDropBoxes) {
1672                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1673                 return res, err
1674         }
1675
1676         fileNames, err := getFileNameList(fullPath, cc.Server.Config.IgnoreFiles)
1677         if err != nil {
1678                 return res, err
1679         }
1680
1681         res = append(res, cc.NewReply(t, fileNames...))
1682
1683         return res, err
1684 }
1685
1686 // =================================
1687 //     Hotline private chat flow
1688 // =================================
1689 // 1. ClientA sends tranInviteNewChat to server with user ID to invite
1690 // 2. Server creates new ChatID
1691 // 3. Server sends tranInviteToChat to invitee
1692 // 4. Server replies to ClientA with new Chat ID
1693 //
1694 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1695 // If Accepted is clicked:
1696 // 1. ClientB sends tranJoinChat with fieldChatID
1697
1698 // HandleInviteNewChat invites users to new private chat
1699 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1700         if !authorize(cc.Account.Access, accessOpenChat) {
1701                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1702                 return res, err
1703         }
1704
1705         // Client to Invite
1706         targetID := t.GetField(fieldUserID).Data
1707         newChatID := cc.Server.NewPrivateChat(cc)
1708
1709         res = append(res,
1710                 *NewTransaction(
1711                         tranInviteToChat,
1712                         &targetID,
1713                         NewField(fieldChatID, newChatID),
1714                         NewField(fieldUserName, cc.UserName),
1715                         NewField(fieldUserID, *cc.ID),
1716                 ),
1717         )
1718
1719         res = append(res,
1720                 cc.NewReply(t,
1721                         NewField(fieldChatID, newChatID),
1722                         NewField(fieldUserName, cc.UserName),
1723                         NewField(fieldUserID, *cc.ID),
1724                         NewField(fieldUserIconID, cc.Icon),
1725                         NewField(fieldUserFlags, cc.Flags),
1726                 ),
1727         )
1728
1729         return res, err
1730 }
1731
1732 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1733         if !authorize(cc.Account.Access, accessOpenChat) {
1734                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1735                 return res, err
1736         }
1737
1738         // Client to Invite
1739         targetID := t.GetField(fieldUserID).Data
1740         chatID := t.GetField(fieldChatID).Data
1741
1742         res = append(res,
1743                 *NewTransaction(
1744                         tranInviteToChat,
1745                         &targetID,
1746                         NewField(fieldChatID, chatID),
1747                         NewField(fieldUserName, cc.UserName),
1748                         NewField(fieldUserID, *cc.ID),
1749                 ),
1750         )
1751         res = append(res,
1752                 cc.NewReply(
1753                         t,
1754                         NewField(fieldChatID, chatID),
1755                         NewField(fieldUserName, cc.UserName),
1756                         NewField(fieldUserID, *cc.ID),
1757                         NewField(fieldUserIconID, cc.Icon),
1758                         NewField(fieldUserFlags, cc.Flags),
1759                 ),
1760         )
1761
1762         return res, err
1763 }
1764
1765 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1766         chatID := t.GetField(fieldChatID).Data
1767         chatInt := binary.BigEndian.Uint32(chatID)
1768
1769         privChat := cc.Server.PrivateChats[chatInt]
1770
1771         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1772
1773         for _, c := range sortedClients(privChat.ClientConn) {
1774                 res = append(res,
1775                         *NewTransaction(
1776                                 tranChatMsg,
1777                                 c.ID,
1778                                 NewField(fieldChatID, chatID),
1779                                 NewField(fieldData, resMsg),
1780                         ),
1781                 )
1782         }
1783
1784         return res, err
1785 }
1786
1787 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1788 // Fields used in the reply:
1789 // * 115        Chat subject
1790 // * 300        User name with info (Optional)
1791 // * 300        (more user names with info)
1792 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1793         chatID := t.GetField(fieldChatID).Data
1794         chatInt := binary.BigEndian.Uint32(chatID)
1795
1796         privChat := cc.Server.PrivateChats[chatInt]
1797
1798         // Send tranNotifyChatChangeUser to current members of the chat to inform of new user
1799         for _, c := range sortedClients(privChat.ClientConn) {
1800                 res = append(res,
1801                         *NewTransaction(
1802                                 tranNotifyChatChangeUser,
1803                                 c.ID,
1804                                 NewField(fieldChatID, chatID),
1805                                 NewField(fieldUserName, cc.UserName),
1806                                 NewField(fieldUserID, *cc.ID),
1807                                 NewField(fieldUserIconID, cc.Icon),
1808                                 NewField(fieldUserFlags, cc.Flags),
1809                         ),
1810                 )
1811         }
1812
1813         privChat.ClientConn[cc.uint16ID()] = cc
1814
1815         replyFields := []Field{NewField(fieldChatSubject, []byte(privChat.Subject))}
1816         for _, c := range sortedClients(privChat.ClientConn) {
1817                 user := User{
1818                         ID:    *c.ID,
1819                         Icon:  c.Icon,
1820                         Flags: c.Flags,
1821                         Name:  string(c.UserName),
1822                 }
1823
1824                 replyFields = append(replyFields, NewField(fieldUsernameWithInfo, user.Payload()))
1825         }
1826
1827         res = append(res, cc.NewReply(t, replyFields...))
1828         return res, err
1829 }
1830
1831 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1832 // Fields used in the request:
1833 //      * 114   fieldChatID
1834 // Reply is not expected.
1835 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1836         chatID := t.GetField(fieldChatID).Data
1837         chatInt := binary.BigEndian.Uint32(chatID)
1838
1839         privChat, ok := cc.Server.PrivateChats[chatInt]
1840         if !ok {
1841                 return res, nil
1842         }
1843
1844         delete(privChat.ClientConn, cc.uint16ID())
1845
1846         // Notify members of the private chat that the user has left
1847         for _, c := range sortedClients(privChat.ClientConn) {
1848                 res = append(res,
1849                         *NewTransaction(
1850                                 tranNotifyChatDeleteUser,
1851                                 c.ID,
1852                                 NewField(fieldChatID, chatID),
1853                                 NewField(fieldUserID, *cc.ID),
1854                         ),
1855                 )
1856         }
1857
1858         return res, err
1859 }
1860
1861 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1862 // Fields used in the request:
1863 // * 114        Chat ID
1864 // * 115        Chat subject    Chat subject string
1865 // Reply is not expected.
1866 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1867         chatID := t.GetField(fieldChatID).Data
1868         chatInt := binary.BigEndian.Uint32(chatID)
1869
1870         privChat := cc.Server.PrivateChats[chatInt]
1871         privChat.Subject = string(t.GetField(fieldChatSubject).Data)
1872
1873         for _, c := range sortedClients(privChat.ClientConn) {
1874                 res = append(res,
1875                         *NewTransaction(
1876                                 tranNotifyChatSubject,
1877                                 c.ID,
1878                                 NewField(fieldChatID, chatID),
1879                                 NewField(fieldChatSubject, t.GetField(fieldChatSubject).Data),
1880                         ),
1881                 )
1882         }
1883
1884         return res, err
1885 }
1886
1887 // HandleMakeAlias makes a filer alias using the specified path.
1888 // Fields used in the request:
1889 // 201  File name
1890 // 202  File path
1891 // 212  File new path   Destination path
1892 //
1893 // Fields used in the reply:
1894 // None
1895 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1896         if !authorize(cc.Account.Access, accessMakeAlias) {
1897                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1898                 return res, err
1899         }
1900         fileName := t.GetField(fieldFileName).Data
1901         filePath := t.GetField(fieldFilePath).Data
1902         fileNewPath := t.GetField(fieldFileNewPath).Data
1903
1904         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1905         if err != nil {
1906                 return res, err
1907         }
1908
1909         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1910         if err != nil {
1911                 return res, err
1912         }
1913
1914         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1915
1916         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
1917                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
1918                 return res, nil
1919         }
1920
1921         res = append(res, cc.NewReply(t))
1922         return res, err
1923 }
1924
1925 func HandleDownloadBanner(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1926         fi, err := cc.Server.FS.Stat(filepath.Join(cc.Server.ConfigDir, cc.Server.Config.BannerFile))
1927         if err != nil {
1928                 return res, err
1929         }
1930
1931         ft := cc.newFileTransfer(bannerDownload, []byte{}, []byte{}, make([]byte, 4))
1932
1933         binary.BigEndian.PutUint32(ft.TransferSize, uint32(fi.Size()))
1934
1935         res = append(res, cc.NewReply(t,
1936                 NewField(fieldRefNum, ft.refNum[:]),
1937                 NewField(fieldTransferSize, ft.TransferSize),
1938         ))
1939
1940         return res, err
1941 }