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 TransactionType struct {
  19         Handler        func(*ClientConn, *Transaction) ([]Transaction, error) // function for handling the transaction type
  20         Name           string                                                 // Name of transaction as it will appear in logging
  21         RequiredFields []requiredField
  22 }
  23
  24 var TransactionHandlers = map[uint16]TransactionType{
  25         // Server initiated
  26         tranChatMsg: {
  27                 Name: "tranChatMsg",
  28         },
  29         // Server initiated
  30         tranNotifyChangeUser: {
  31                 Name: "tranNotifyChangeUser",
  32         },
  33         tranError: {
  34                 Name: "tranError",
  35         },
  36         tranShowAgreement: {
  37                 Name: "tranShowAgreement",
  38         },
  39         tranUserAccess: {
  40                 Name: "tranUserAccess",
  41         },
  42         tranNotifyDeleteUser: {
  43                 Name: "tranNotifyDeleteUser",
  44         },
  45         tranAgreed: {
  46                 Name:    "tranAgreed",
  47                 Handler: HandleTranAgreed,
  48         },
  49         tranChatSend: {
  50                 Name:    "tranChatSend",
  51                 Handler: HandleChatSend,
  52                 RequiredFields: []requiredField{
  53                         {
  54                                 ID:     fieldData,
  55                                 minLen: 0,
  56                         },
  57                 },
  58         },
  59         tranDelNewsArt: {
  60                 Name:    "tranDelNewsArt",
  61                 Handler: HandleDelNewsArt,
  62         },
  63         tranDelNewsItem: {
  64                 Name:    "tranDelNewsItem",
  65                 Handler: HandleDelNewsItem,
  66         },
  67         tranDeleteFile: {
  68                 Name:    "tranDeleteFile",
  69                 Handler: HandleDeleteFile,
  70         },
  71         tranDeleteUser: {
  72                 Name:    "tranDeleteUser",
  73                 Handler: HandleDeleteUser,
  74         },
  75         tranDisconnectUser: {
  76                 Name:    "tranDisconnectUser",
  77                 Handler: HandleDisconnectUser,
  78         },
  79         tranDownloadFile: {
  80                 Name:    "tranDownloadFile",
  81                 Handler: HandleDownloadFile,
  82         },
  83         tranDownloadFldr: {
  84                 Name:    "tranDownloadFldr",
  85                 Handler: HandleDownloadFolder,
  86         },
  87         tranGetClientInfoText: {
  88                 Name:    "tranGetClientInfoText",
  89                 Handler: HandleGetClientInfoText,
  90         },
  91         tranGetFileInfo: {
  92                 Name:    "tranGetFileInfo",
  93                 Handler: HandleGetFileInfo,
  94         },
  95         tranGetFileNameList: {
  96                 Name:    "tranGetFileNameList",
  97                 Handler: HandleGetFileNameList,
  98         },
  99         tranGetMsgs: {
 100                 Name:    "tranGetMsgs",
 101                 Handler: HandleGetMsgs,
 102         },
 103         tranGetNewsArtData: {
 104                 Name:    "tranGetNewsArtData",
 105                 Handler: HandleGetNewsArtData,
 106         },
 107         tranGetNewsArtNameList: {
 108                 Name:    "tranGetNewsArtNameList",
 109                 Handler: HandleGetNewsArtNameList,
 110         },
 111         tranGetNewsCatNameList: {
 112                 Name:    "tranGetNewsCatNameList",
 113                 Handler: HandleGetNewsCatNameList,
 114         },
 115         tranGetUser: {
 116                 Name:    "tranGetUser",
 117                 Handler: HandleGetUser,
 118         },
 119         tranGetUserNameList: {
 120                 Name:    "tranHandleGetUserNameList",
 121                 Handler: HandleGetUserNameList,
 122         },
 123         tranInviteNewChat: {
 124                 Name:    "tranInviteNewChat",
 125                 Handler: HandleInviteNewChat,
 126         },
 127         tranInviteToChat: {
 128                 Name:    "tranInviteToChat",
 129                 Handler: HandleInviteToChat,
 130         },
 131         tranJoinChat: {
 132                 Name:    "tranJoinChat",
 133                 Handler: HandleJoinChat,
 134         },
 135         tranKeepAlive: {
 136                 Name:    "tranKeepAlive",
 137                 Handler: HandleKeepAlive,
 138         },
 139         tranLeaveChat: {
 140                 Name:    "tranJoinChat",
 141                 Handler: HandleLeaveChat,
 142         },
 143         tranListUsers: {
 144                 Name:    "tranListUsers",
 145                 Handler: HandleListUsers,
 146         },
 147         tranMoveFile: {
 148                 Name:    "tranMoveFile",
 149                 Handler: HandleMoveFile,
 150         },
 151         tranNewFolder: {
 152                 Name:    "tranNewFolder",
 153                 Handler: HandleNewFolder,
 154         },
 155         tranNewNewsCat: {
 156                 Name:    "tranNewNewsCat",
 157                 Handler: HandleNewNewsCat,
 158         },
 159         tranNewNewsFldr: {
 160                 Name:    "tranNewNewsFldr",
 161                 Handler: HandleNewNewsFldr,
 162         },
 163         tranNewUser: {
 164                 Name:    "tranNewUser",
 165                 Handler: HandleNewUser,
 166         },
 167         tranUpdateUser: {
 168                 Name:    "tranUpdateUser",
 169                 Handler: HandleUpdateUser,
 170         },
 171         tranOldPostNews: {
 172                 Name:    "tranOldPostNews",
 173                 Handler: HandleTranOldPostNews,
 174         },
 175         tranPostNewsArt: {
 176                 Name:    "tranPostNewsArt",
 177                 Handler: HandlePostNewsArt,
 178         },
 179         tranRejectChatInvite: {
 180                 Name:    "tranRejectChatInvite",
 181                 Handler: HandleRejectChatInvite,
 182         },
 183         tranSendInstantMsg: {
 184                 Name:    "tranSendInstantMsg",
 185                 Handler: HandleSendInstantMsg,
 186                 RequiredFields: []requiredField{
 187                         {
 188                                 ID:     fieldData,
 189                                 minLen: 0,
 190                         },
 191                         {
 192                                 ID: fieldUserID,
 193                         },
 194                 },
 195         },
 196         tranSetChatSubject: {
 197                 Name:    "tranSetChatSubject",
 198                 Handler: HandleSetChatSubject,
 199         },
 200         tranMakeFileAlias: {
 201                 Name:    "tranMakeFileAlias",
 202                 Handler: HandleMakeAlias,
 203                 RequiredFields: []requiredField{
 204                         {ID: fieldFileName, minLen: 1},
 205                         {ID: fieldFilePath, minLen: 1},
 206                         {ID: fieldFileNewPath, minLen: 1},
 207                 },
 208         },
 209         tranSetClientUserInfo: {
 210                 Name:    "tranSetClientUserInfo",
 211                 Handler: HandleSetClientUserInfo,
 212         },
 213         tranSetFileInfo: {
 214                 Name:    "tranSetFileInfo",
 215                 Handler: HandleSetFileInfo,
 216         },
 217         tranSetUser: {
 218                 Name:    "tranSetUser",
 219                 Handler: HandleSetUser,
 220         },
 221         tranUploadFile: {
 222                 Name:    "tranUploadFile",
 223                 Handler: HandleUploadFile,
 224         },
 225         tranUploadFldr: {
 226                 Name:    "tranUploadFldr",
 227                 Handler: HandleUploadFolder,
 228         },
 229         tranUserBroadcast: {
 230                 Name:    "tranUserBroadcast",
 231                 Handler: HandleUserBroadcast,
 232         },
 233         tranDownloadBanner: {
 234                 Name:    "tranDownloadBanner",
 235                 Handler: HandleDownloadBanner,
 236         },
 237 }
 238
 239 func HandleChatSend(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 240         if !cc.Authorize(accessSendChat) {
 241                 res = append(res, cc.NewErrReply(t, "You are not allowed to participate in chat."))
 242                 return res, err
 243         }
 244
 245         // Truncate long usernames
 246         trunc := fmt.Sprintf("%13s", cc.UserName)
 247         formattedMsg := fmt.Sprintf("\r%.14s:  %s", trunc, t.GetField(fieldData).Data)
 248
 249         // By holding the option key, Hotline chat allows users to send /me formatted messages like:
 250         // *** Halcyon does stuff
 251         // This is indicated by the presence of the optional field fieldChatOptions in the transaction payload
 252         if t.GetField(fieldChatOptions).Data != nil {
 253                 formattedMsg = fmt.Sprintf("\r*** %s %s", cc.UserName, t.GetField(fieldData).Data)
 254         }
 255
 256         chatID := t.GetField(fieldChatID).Data
 257         // a non-nil chatID indicates the message belongs to a private chat
 258         if chatID != nil {
 259                 chatInt := binary.BigEndian.Uint32(chatID)
 260                 privChat := cc.Server.PrivateChats[chatInt]
 261
 262                 clients := sortedClients(privChat.ClientConn)
 263
 264                 // send the message to all connected clients of the private chat
 265                 for _, c := range clients {
 266                         res = append(res, *NewTransaction(
 267                                 tranChatMsg,
 268                                 c.ID,
 269                                 NewField(fieldChatID, chatID),
 270                                 NewField(fieldData, []byte(formattedMsg)),
 271                         ))
 272                 }
 273                 return res, err
 274         }
 275
 276         for _, c := range sortedClients(cc.Server.Clients) {
 277                 // Filter out clients that do not have the read chat permission
 278                 if c.Authorize(accessReadChat) {
 279                         res = append(res, *NewTransaction(tranChatMsg, c.ID, NewField(fieldData, []byte(formattedMsg))))
 280                 }
 281         }
 282
 283         return res, err
 284 }
 285
 286 // HandleSendInstantMsg sends instant message to the user on the current server.
 287 // Fields used in the request:
 288 //      103     User ID
 289 //      113     Options
 290 //              One of the following values:
 291 //              - User message (myOpt_UserMessage = 1)
 292 //              - Refuse message (myOpt_RefuseMessage = 2)
 293 //              - Refuse chat (myOpt_RefuseChat  = 3)
 294 //              - Automatic response (myOpt_AutomaticResponse = 4)"
 295 //      101     Data    Optional
 296 //      214     Quoting message Optional
 297 //
 298 // Fields used in the reply:
 299 // None
 300 func HandleSendInstantMsg(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 301         if !cc.Authorize(accessSendPrivMsg) {
 302                 res = append(res, cc.NewErrReply(t, "You are not allowed to send private messages."))
 303                 return res, err
 304         }
 305
 306         msg := t.GetField(fieldData)
 307         ID := t.GetField(fieldUserID)
 308
 309         reply := NewTransaction(
 310                 tranServerMsg,
 311                 &ID.Data,
 312                 NewField(fieldData, msg.Data),
 313                 NewField(fieldUserName, cc.UserName),
 314                 NewField(fieldUserID, *cc.ID),
 315                 NewField(fieldOptions, []byte{0, 1}),
 316         )
 317
 318         // Later versions of Hotline include the original message in the fieldQuotingMsg field so
 319         //  the receiving client can display both the received message and what it is in reply to
 320         if t.GetField(fieldQuotingMsg).Data != nil {
 321                 reply.Fields = append(reply.Fields, NewField(fieldQuotingMsg, t.GetField(fieldQuotingMsg).Data))
 322         }
 323
 324         id, _ := byteToInt(ID.Data)
 325         otherClient, ok := cc.Server.Clients[uint16(id)]
 326         if !ok {
 327                 return res, errors.New("invalid client ID")
 328         }
 329
 330         // Check if target user has "Refuse private messages" flag
 331         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(otherClient.Flags)))
 332         if flagBitmap.Bit(userFLagRefusePChat) == 1 {
 333                 res = append(res,
 334                         *NewTransaction(
 335                                 tranServerMsg,
 336                                 cc.ID,
 337                                 NewField(fieldData, []byte(string(otherClient.UserName)+" does not accept private messages.")),
 338                                 NewField(fieldUserName, otherClient.UserName),
 339                                 NewField(fieldUserID, *otherClient.ID),
 340                                 NewField(fieldOptions, []byte{0, 2}),
 341                         ),
 342                 )
 343         } else {
 344                 res = append(res, *reply)
 345         }
 346
 347         // Respond with auto reply if other client has it enabled
 348         if len(otherClient.AutoReply) > 0 {
 349                 res = append(res,
 350                         *NewTransaction(
 351                                 tranServerMsg,
 352                                 cc.ID,
 353                                 NewField(fieldData, otherClient.AutoReply),
 354                                 NewField(fieldUserName, otherClient.UserName),
 355                                 NewField(fieldUserID, *otherClient.ID),
 356                                 NewField(fieldOptions, []byte{0, 1}),
 357                         ),
 358                 )
 359         }
 360
 361         res = append(res, cc.NewReply(t))
 362
 363         return res, err
 364 }
 365
 366 func HandleGetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 367         fileName := t.GetField(fieldFileName).Data
 368         filePath := t.GetField(fieldFilePath).Data
 369
 370         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 371         if err != nil {
 372                 return res, err
 373         }
 374
 375         fw, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 376         if err != nil {
 377                 return res, err
 378         }
 379
 380         res = append(res, cc.NewReply(t,
 381                 NewField(fieldFileName, []byte(fw.name)),
 382                 NewField(fieldFileTypeString, fw.ffo.FlatFileInformationFork.friendlyType()),
 383                 NewField(fieldFileCreatorString, fw.ffo.FlatFileInformationFork.friendlyCreator()),
 384                 NewField(fieldFileComment, fw.ffo.FlatFileInformationFork.Comment),
 385                 NewField(fieldFileType, fw.ffo.FlatFileInformationFork.TypeSignature),
 386                 NewField(fieldFileCreateDate, fw.ffo.FlatFileInformationFork.CreateDate),
 387                 NewField(fieldFileModifyDate, fw.ffo.FlatFileInformationFork.ModifyDate),
 388                 NewField(fieldFileSize, fw.totalSize()),
 389         ))
 390         return res, err
 391 }
 392
 393 // HandleSetFileInfo updates a file or folder name and/or comment from the Get Info window
 394 // Fields used in the request:
 395 // * 201        File name
 396 // * 202        File path       Optional
 397 // * 211        File new name   Optional
 398 // * 210        File comment    Optional
 399 // Fields used in the reply:    None
 400 func HandleSetFileInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 401         fileName := t.GetField(fieldFileName).Data
 402         filePath := t.GetField(fieldFilePath).Data
 403
 404         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 405         if err != nil {
 406                 return res, err
 407         }
 408
 409         fi, err := cc.Server.FS.Stat(fullFilePath)
 410         if err != nil {
 411                 return res, err
 412         }
 413
 414         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 415         if err != nil {
 416                 return res, err
 417         }
 418         if t.GetField(fieldFileComment).Data != nil {
 419                 switch mode := fi.Mode(); {
 420                 case mode.IsDir():
 421                         if !cc.Authorize(accessSetFolderComment) {
 422                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for folders."))
 423                                 return res, err
 424                         }
 425                 case mode.IsRegular():
 426                         if !cc.Authorize(accessSetFileComment) {
 427                                 res = append(res, cc.NewErrReply(t, "You are not allowed to set comments for files."))
 428                                 return res, err
 429                         }
 430                 }
 431
 432                 if err := hlFile.ffo.FlatFileInformationFork.setComment(t.GetField(fieldFileComment).Data); err != nil {
 433                         return res, err
 434                 }
 435                 w, err := hlFile.infoForkWriter()
 436                 if err != nil {
 437                         return res, err
 438                 }
 439                 _, err = w.Write(hlFile.ffo.FlatFileInformationFork.MarshalBinary())
 440                 if err != nil {
 441                         return res, err
 442                 }
 443         }
 444
 445         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, t.GetField(fieldFileNewName).Data)
 446         if err != nil {
 447                 return nil, err
 448         }
 449
 450         fileNewName := t.GetField(fieldFileNewName).Data
 451
 452         if fileNewName != nil {
 453                 switch mode := fi.Mode(); {
 454                 case mode.IsDir():
 455                         if !cc.Authorize(accessRenameFolder) {
 456                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename folders."))
 457                                 return res, err
 458                         }
 459                         err = os.Rename(fullFilePath, fullNewFilePath)
 460                         if os.IsNotExist(err) {
 461                                 res = append(res, cc.NewErrReply(t, "Cannot rename folder "+string(fileName)+" because it does not exist or cannot be found."))
 462                                 return res, err
 463                         }
 464                 case mode.IsRegular():
 465                         if !cc.Authorize(accessRenameFile) {
 466                                 res = append(res, cc.NewErrReply(t, "You are not allowed to rename files."))
 467                                 return res, err
 468                         }
 469                         fileDir, err := readPath(cc.Server.Config.FileRoot, filePath, []byte{})
 470                         if err != nil {
 471                                 return nil, err
 472                         }
 473                         hlFile.name = string(fileNewName)
 474                         err = hlFile.move(fileDir)
 475                         if os.IsNotExist(err) {
 476                                 res = append(res, cc.NewErrReply(t, "Cannot rename file "+string(fileName)+" because it does not exist or cannot be found."))
 477                                 return res, err
 478                         }
 479                         if err != nil {
 480                                 return res, err
 481                         }
 482                 }
 483         }
 484
 485         res = append(res, cc.NewReply(t))
 486         return res, err
 487 }
 488
 489 // HandleDeleteFile deletes a file or folder
 490 // Fields used in the request:
 491 // * 201        File name
 492 // * 202        File path
 493 // Fields used in the reply: none
 494 func HandleDeleteFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 495         fileName := t.GetField(fieldFileName).Data
 496         filePath := t.GetField(fieldFilePath).Data
 497
 498         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
 499         if err != nil {
 500                 return res, err
 501         }
 502
 503         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, 0)
 504         if err != nil {
 505                 return res, err
 506         }
 507
 508         fi, err := hlFile.dataFile()
 509         if err != nil {
 510                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+string(fileName)+" because it does not exist or cannot be found."))
 511                 return res, nil
 512         }
 513
 514         switch mode := fi.Mode(); {
 515         case mode.IsDir():
 516                 if !cc.Authorize(accessDeleteFolder) {
 517                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete folders."))
 518                         return res, err
 519                 }
 520         case mode.IsRegular():
 521                 if !cc.Authorize(accessDeleteFile) {
 522                         res = append(res, cc.NewErrReply(t, "You are not allowed to delete files."))
 523                         return res, err
 524                 }
 525         }
 526
 527         if err := hlFile.delete(); err != nil {
 528                 return res, err
 529         }
 530
 531         res = append(res, cc.NewReply(t))
 532         return res, err
 533 }
 534
 535 // HandleMoveFile moves files or folders. Note: seemingly not documented
 536 func HandleMoveFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 537         fileName := string(t.GetField(fieldFileName).Data)
 538
 539         filePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
 540         if err != nil {
 541                 return res, err
 542         }
 543
 544         fileNewPath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFileNewPath).Data, nil)
 545         if err != nil {
 546                 return res, err
 547         }
 548
 549         cc.logger.Infow("Move file", "src", filePath+"/"+fileName, "dst", fileNewPath+"/"+fileName)
 550
 551         hlFile, err := newFileWrapper(cc.Server.FS, filePath, 0)
 552         if err != nil {
 553                 return res, err
 554         }
 555
 556         fi, err := hlFile.dataFile()
 557         if err != nil {
 558                 res = append(res, cc.NewErrReply(t, "Cannot delete file "+fileName+" because it does not exist or cannot be found."))
 559                 return res, err
 560         }
 561         if err != nil {
 562                 return res, err
 563         }
 564         switch mode := fi.Mode(); {
 565         case mode.IsDir():
 566                 if !cc.Authorize(accessMoveFolder) {
 567                         res = append(res, cc.NewErrReply(t, "You are not allowed to move folders."))
 568                         return res, err
 569                 }
 570         case mode.IsRegular():
 571                 if !cc.Authorize(accessMoveFile) {
 572                         res = append(res, cc.NewErrReply(t, "You are not allowed to move files."))
 573                         return res, err
 574                 }
 575         }
 576         if err := hlFile.move(fileNewPath); err != nil {
 577                 return res, err
 578         }
 579         // TODO: handle other possible errors; e.g. fileWrapper delete fails due to fileWrapper permission issue
 580
 581         res = append(res, cc.NewReply(t))
 582         return res, err
 583 }
 584
 585 func HandleNewFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 586         if !cc.Authorize(accessCreateFolder) {
 587                 res = append(res, cc.NewErrReply(t, "You are not allowed to create folders."))
 588                 return res, err
 589         }
 590         folderName := string(t.GetField(fieldFileName).Data)
 591
 592         folderName = path.Join("/", folderName)
 593
 594         var subPath string
 595
 596         // fieldFilePath is only present for nested paths
 597         if t.GetField(fieldFilePath).Data != nil {
 598                 var newFp FilePath
 599                 _, err := newFp.Write(t.GetField(fieldFilePath).Data)
 600                 if err != nil {
 601                         return nil, err
 602                 }
 603
 604                 for _, pathItem := range newFp.Items {
 605                         subPath = filepath.Join("/", subPath, string(pathItem.Name))
 606                 }
 607         }
 608         newFolderPath := path.Join(cc.Server.Config.FileRoot, subPath, folderName)
 609
 610         // TODO: check path and folder name lengths
 611
 612         if _, err := cc.Server.FS.Stat(newFolderPath); !os.IsNotExist(err) {
 613                 msg := fmt.Sprintf("Cannot create folder \"%s\" because there is already a file or folder with that name.", folderName)
 614                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 615         }
 616
 617         // TODO: check for disallowed characters to maintain compatibility for original client
 618
 619         if err := cc.Server.FS.Mkdir(newFolderPath, 0777); err != nil {
 620                 msg := fmt.Sprintf("Cannot create folder \"%s\" because an error occurred.", folderName)
 621                 return []Transaction{cc.NewErrReply(t, msg)}, nil
 622         }
 623
 624         res = append(res, cc.NewReply(t))
 625         return res, err
 626 }
 627
 628 func HandleSetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 629         if !cc.Authorize(accessModifyUser) {
 630                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 631                 return res, err
 632         }
 633
 634         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 635         userName := string(t.GetField(fieldUserName).Data)
 636
 637         newAccessLvl := t.GetField(fieldUserAccess).Data
 638
 639         account := cc.Server.Accounts[login]
 640         account.Name = userName
 641         copy(account.Access[:], newAccessLvl)
 642
 643         // If the password field is cleared in the Hotline edit user UI, the SetUser transaction does
 644         // not include fieldUserPassword
 645         if t.GetField(fieldUserPassword).Data == nil {
 646                 account.Password = hashAndSalt([]byte(""))
 647         }
 648         if len(t.GetField(fieldUserPassword).Data) > 1 {
 649                 account.Password = hashAndSalt(t.GetField(fieldUserPassword).Data)
 650         }
 651
 652         out, err := yaml.Marshal(&account)
 653         if err != nil {
 654                 return res, err
 655         }
 656         if err := os.WriteFile(filepath.Join(cc.Server.ConfigDir, "Users", login+".yaml"), out, 0666); err != nil {
 657                 return res, err
 658         }
 659
 660         // Notify connected clients logged in as the user of the new access level
 661         for _, c := range cc.Server.Clients {
 662                 if c.Account.Login == login {
 663                         // Note: comment out these two lines to test server-side deny messages
 664                         newT := NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, newAccessLvl))
 665                         res = append(res, *newT)
 666
 667                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(c.Flags)))
 668                         if c.Authorize(accessDisconUser) {
 669                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 1)
 670                         } else {
 671                                 flagBitmap.SetBit(flagBitmap, userFlagAdmin, 0)
 672                         }
 673                         binary.BigEndian.PutUint16(c.Flags, uint16(flagBitmap.Int64()))
 674
 675                         c.Account.Access = account.Access
 676
 677                         cc.sendAll(
 678                                 tranNotifyChangeUser,
 679                                 NewField(fieldUserID, *c.ID),
 680                                 NewField(fieldUserFlags, c.Flags),
 681                                 NewField(fieldUserName, c.UserName),
 682                                 NewField(fieldUserIconID, c.Icon),
 683                         )
 684                 }
 685         }
 686
 687         res = append(res, cc.NewReply(t))
 688         return res, err
 689 }
 690
 691 func HandleGetUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 692         if !cc.Authorize(accessOpenUser) {
 693                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 694                 return res, err
 695         }
 696
 697         account := cc.Server.Accounts[string(t.GetField(fieldUserLogin).Data)]
 698         if account == nil {
 699                 res = append(res, cc.NewErrReply(t, "Account does not exist."))
 700                 return res, err
 701         }
 702
 703         res = append(res, cc.NewReply(t,
 704                 NewField(fieldUserName, []byte(account.Name)),
 705                 NewField(fieldUserLogin, negateString(t.GetField(fieldUserLogin).Data)),
 706                 NewField(fieldUserPassword, []byte(account.Password)),
 707                 NewField(fieldUserAccess, account.Access[:]),
 708         ))
 709         return res, err
 710 }
 711
 712 func HandleListUsers(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 713         if !cc.Authorize(accessOpenUser) {
 714                 res = append(res, cc.NewErrReply(t, "You are not allowed to view accounts."))
 715                 return res, err
 716         }
 717
 718         var userFields []Field
 719         for _, acc := range cc.Server.Accounts {
 720                 b := make([]byte, 0, 100)
 721                 n, err := acc.Read(b)
 722                 if err != nil {
 723                         return res, err
 724                 }
 725
 726                 userFields = append(userFields, NewField(fieldData, b[:n]))
 727         }
 728
 729         res = append(res, cc.NewReply(t, userFields...))
 730         return res, err
 731 }
 732
 733 // HandleUpdateUser is used by the v1.5+ multi-user editor to perform account editing for multiple users at a time.
 734 // An update can be a mix of these actions:
 735 // * Create user
 736 // * Delete user
 737 // * Modify user (including renaming the account login)
 738 //
 739 // The Transaction sent by the client includes one data field per user that was modified.  This data field in turn
 740 // contains another data field encoded in its payload with a varying number of sub fields depending on which action is
 741 // performed.  This seems to be the only place in the Hotline protocol where a data field contains another data field.
 742 func HandleUpdateUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 743         for _, field := range t.Fields {
 744                 subFields, err := ReadFields(field.Data[0:2], field.Data[2:])
 745                 if err != nil {
 746                         return res, err
 747                 }
 748
 749                 if len(subFields) == 1 {
 750                         login := DecodeUserString(getField(fieldData, &subFields).Data)
 751                         cc.logger.Infow("DeleteUser", "login", login)
 752
 753                         if !cc.Authorize(accessDeleteUser) {
 754                                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 755                                 return res, err
 756                         }
 757
 758                         if err := cc.Server.DeleteUser(login); err != nil {
 759                                 return res, err
 760                         }
 761                         continue
 762                 }
 763
 764                 login := DecodeUserString(getField(fieldUserLogin, &subFields).Data)
 765
 766                 // check if the login dataFile; if so, we know we are updating an existing user
 767                 if acc, ok := cc.Server.Accounts[login]; ok {
 768                         cc.logger.Infow("UpdateUser", "login", login)
 769
 770                         // account dataFile, so this is an update action
 771                         if !cc.Authorize(accessModifyUser) {
 772                                 res = append(res, cc.NewErrReply(t, "You are not allowed to modify accounts."))
 773                                 return res, err
 774                         }
 775
 776                         if getField(fieldUserPassword, &subFields) != nil {
 777                                 newPass := getField(fieldUserPassword, &subFields).Data
 778                                 acc.Password = hashAndSalt(newPass)
 779                         } else {
 780                                 acc.Password = hashAndSalt([]byte(""))
 781                         }
 782
 783                         if getField(fieldUserAccess, &subFields) != nil {
 784                                 copy(acc.Access[:], getField(fieldUserAccess, &subFields).Data)
 785                         }
 786
 787                         err = cc.Server.UpdateUser(
 788                                 DecodeUserString(getField(fieldData, &subFields).Data),
 789                                 DecodeUserString(getField(fieldUserLogin, &subFields).Data),
 790                                 string(getField(fieldUserName, &subFields).Data),
 791                                 acc.Password,
 792                                 acc.Access,
 793                         )
 794                         if err != nil {
 795                                 return res, err
 796                         }
 797                 } else {
 798                         cc.logger.Infow("CreateUser", "login", login)
 799
 800                         if !cc.Authorize(accessCreateUser) {
 801                                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 802                                 return res, err
 803                         }
 804
 805                         newAccess := accessBitmap{}
 806                         copy(newAccess[:], getField(fieldUserAccess, &subFields).Data[:])
 807
 808                         // Prevent account from creating new account with greater permission
 809                         for i := 0; i < 64; i++ {
 810                                 if newAccess.IsSet(i) {
 811                                         if !cc.Authorize(i) {
 812                                                 return append(res, cc.NewErrReply(t, "Cannot create account with more access than yourself.")), err
 813                                         }
 814                                 }
 815                         }
 816
 817                         err := cc.Server.NewUser(login, string(getField(fieldUserName, &subFields).Data), string(getField(fieldUserPassword, &subFields).Data), newAccess)
 818                         if err != nil {
 819                                 return []Transaction{}, err
 820                         }
 821                 }
 822         }
 823
 824         res = append(res, cc.NewReply(t))
 825         return res, err
 826 }
 827
 828 // HandleNewUser creates a new user account
 829 func HandleNewUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 830         if !cc.Authorize(accessCreateUser) {
 831                 res = append(res, cc.NewErrReply(t, "You are not allowed to create new accounts."))
 832                 return res, err
 833         }
 834
 835         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 836
 837         // If the account already dataFile, reply with an error
 838         if _, ok := cc.Server.Accounts[login]; ok {
 839                 res = append(res, cc.NewErrReply(t, "Cannot create account "+login+" because there is already an account with that login."))
 840                 return res, err
 841         }
 842
 843         newAccess := accessBitmap{}
 844         copy(newAccess[:], t.GetField(fieldUserAccess).Data[:])
 845
 846         // Prevent account from creating new account with greater permission
 847         for i := 0; i < 64; i++ {
 848                 if newAccess.IsSet(i) {
 849                         if !cc.Authorize(i) {
 850                                 res = append(res, cc.NewErrReply(t, "Cannot create account with more access than yourself."))
 851                                 return res, err
 852                         }
 853                 }
 854         }
 855
 856         if err := cc.Server.NewUser(login, string(t.GetField(fieldUserName).Data), string(t.GetField(fieldUserPassword).Data), newAccess); err != nil {
 857                 return []Transaction{}, err
 858         }
 859
 860         res = append(res, cc.NewReply(t))
 861         return res, err
 862 }
 863
 864 func HandleDeleteUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 865         if !cc.Authorize(accessDeleteUser) {
 866                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete accounts."))
 867                 return res, err
 868         }
 869
 870         // TODO: Handle case where account doesn't exist; e.g. delete race condition
 871         login := DecodeUserString(t.GetField(fieldUserLogin).Data)
 872
 873         if err := cc.Server.DeleteUser(login); err != nil {
 874                 return res, err
 875         }
 876
 877         res = append(res, cc.NewReply(t))
 878         return res, err
 879 }
 880
 881 // HandleUserBroadcast sends an Administrator Message to all connected clients of the server
 882 func HandleUserBroadcast(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 883         if !cc.Authorize(accessBroadcast) {
 884                 res = append(res, cc.NewErrReply(t, "You are not allowed to send broadcast messages."))
 885                 return res, err
 886         }
 887
 888         cc.sendAll(
 889                 tranServerMsg,
 890                 NewField(fieldData, t.GetField(tranGetMsgs).Data),
 891                 NewField(fieldChatOptions, []byte{0}),
 892         )
 893
 894         res = append(res, cc.NewReply(t))
 895         return res, err
 896 }
 897
 898 func byteToInt(bytes []byte) (int, error) {
 899         switch len(bytes) {
 900         case 2:
 901                 return int(binary.BigEndian.Uint16(bytes)), nil
 902         case 4:
 903                 return int(binary.BigEndian.Uint32(bytes)), nil
 904         }
 905
 906         return 0, errors.New("unknown byte length")
 907 }
 908
 909 // HandleGetClientInfoText returns user information for the specific user.
 910 //
 911 // Fields used in the request:
 912 // 103  User ID
 913 //
 914 // Fields used in the reply:
 915 // 102  User name
 916 // 101  Data            User info text string
 917 func HandleGetClientInfoText(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 918         if !cc.Authorize(accessGetClientInfo) {
 919                 res = append(res, cc.NewErrReply(t, "You are not allowed to get client info."))
 920                 return res, err
 921         }
 922
 923         clientID, _ := byteToInt(t.GetField(fieldUserID).Data)
 924
 925         clientConn := cc.Server.Clients[uint16(clientID)]
 926         if clientConn == nil {
 927                 return append(res, cc.NewErrReply(t, "User not found.")), err
 928         }
 929
 930         res = append(res, cc.NewReply(t,
 931                 NewField(fieldData, []byte(clientConn.String())),
 932                 NewField(fieldUserName, clientConn.UserName),
 933         ))
 934         return res, err
 935 }
 936
 937 func HandleGetUserNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 938         res = append(res, cc.NewReply(t, cc.Server.connectedUsers()...))
 939
 940         return res, err
 941 }
 942
 943 func HandleTranAgreed(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
 944         cc.Agreed = true
 945
 946         if t.GetField(fieldUserName).Data != nil {
 947                 if cc.Authorize(accessAnyName) {
 948                         cc.UserName = t.GetField(fieldUserName).Data
 949                 } else {
 950                         cc.UserName = []byte(cc.Account.Name)
 951                 }
 952         }
 953
 954         cc.Icon = t.GetField(fieldUserIconID).Data
 955
 956         cc.logger = cc.logger.With("name", string(cc.UserName))
 957         cc.logger.Infow("Login successful", "clientVersion", fmt.Sprintf("%v", func() int { i, _ := byteToInt(cc.Version); return i }()))
 958
 959         options := t.GetField(fieldOptions).Data
 960         optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
 961
 962         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
 963
 964         // Check refuse private PM option
 965         if optBitmap.Bit(refusePM) == 1 {
 966                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, 1)
 967                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 968         }
 969
 970         // Check refuse private chat option
 971         if optBitmap.Bit(refuseChat) == 1 {
 972                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, 1)
 973                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
 974         }
 975
 976         // Check auto response
 977         if optBitmap.Bit(autoResponse) == 1 {
 978                 cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
 979         } else {
 980                 cc.AutoReply = []byte{}
 981         }
 982
 983         trans := cc.notifyOthers(
 984                 *NewTransaction(
 985                         tranNotifyChangeUser, nil,
 986                         NewField(fieldUserName, cc.UserName),
 987                         NewField(fieldUserID, *cc.ID),
 988                         NewField(fieldUserIconID, cc.Icon),
 989                         NewField(fieldUserFlags, cc.Flags),
 990                 ),
 991         )
 992         res = append(res, trans...)
 993
 994         if cc.Server.Config.BannerFile != "" {
 995                 res = append(res, *NewTransaction(tranServerBanner, cc.ID, NewField(fieldBannerType, []byte("JPEG"))))
 996         }
 997
 998         res = append(res, cc.NewReply(t))
 999
1000         return res, err
1001 }
1002
1003 const defaultNewsDateFormat = "Jan02 15:04" // Jun23 20:49
1004 //  "Mon, 02 Jan 2006 15:04:05 MST"
1005
1006 const defaultNewsTemplate = `From %s (%s):
1007
1008 %s
1009
1010 __________________________________________________________`
1011
1012 // HandleTranOldPostNews updates the flat news
1013 // Fields used in this request:
1014 // 101  Data
1015 func HandleTranOldPostNews(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1016         if !cc.Authorize(accessNewsPostArt) {
1017                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news."))
1018                 return res, err
1019         }
1020
1021         cc.Server.flatNewsMux.Lock()
1022         defer cc.Server.flatNewsMux.Unlock()
1023
1024         newsDateTemplate := defaultNewsDateFormat
1025         if cc.Server.Config.NewsDateFormat != "" {
1026                 newsDateTemplate = cc.Server.Config.NewsDateFormat
1027         }
1028
1029         newsTemplate := defaultNewsTemplate
1030         if cc.Server.Config.NewsDelimiter != "" {
1031                 newsTemplate = cc.Server.Config.NewsDelimiter
1032         }
1033
1034         newsPost := fmt.Sprintf(newsTemplate+"\r", cc.UserName, time.Now().Format(newsDateTemplate), t.GetField(fieldData).Data)
1035         newsPost = strings.Replace(newsPost, "\n", "\r", -1)
1036
1037         // update news in memory
1038         cc.Server.FlatNews = append([]byte(newsPost), cc.Server.FlatNews...)
1039
1040         // update news on disk
1041         if err := cc.Server.FS.WriteFile(filepath.Join(cc.Server.ConfigDir, "MessageBoard.txt"), cc.Server.FlatNews, 0644); err != nil {
1042                 return res, err
1043         }
1044
1045         // Notify all clients of updated news
1046         cc.sendAll(
1047                 tranNewMsg,
1048                 NewField(fieldData, []byte(newsPost)),
1049         )
1050
1051         res = append(res, cc.NewReply(t))
1052         return res, err
1053 }
1054
1055 func HandleDisconnectUser(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1056         if !cc.Authorize(accessDisconUser) {
1057                 res = append(res, cc.NewErrReply(t, "You are not allowed to disconnect users."))
1058                 return res, err
1059         }
1060
1061         clientConn := cc.Server.Clients[binary.BigEndian.Uint16(t.GetField(fieldUserID).Data)]
1062
1063         if clientConn.Authorize(accessCannotBeDiscon) {
1064                 res = append(res, cc.NewErrReply(t, clientConn.Account.Login+" is not allowed to be disconnected."))
1065                 return res, err
1066         }
1067
1068         // If fieldOptions is set, then the client IP is banned in addition to disconnected.
1069         // 00 01 = temporary ban
1070         // 00 02 = permanent ban
1071         if t.GetField(fieldOptions).Data != nil {
1072                 switch t.GetField(fieldOptions).Data[1] {
1073                 case 1:
1074                         // send message: "You are temporarily banned on this server"
1075                         cc.logger.Infow("Disconnect & temporarily ban " + string(clientConn.UserName))
1076
1077                         res = append(res, *NewTransaction(
1078                                 tranServerMsg,
1079                                 clientConn.ID,
1080                                 NewField(fieldData, []byte("You are temporarily banned on this server")),
1081                                 NewField(fieldChatOptions, []byte{0, 0}),
1082                         ))
1083
1084                         banUntil := time.Now().Add(tempBanDuration)
1085                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = &banUntil
1086                         cc.Server.writeBanList()
1087                 case 2:
1088                         // send message: "You are permanently banned on this server"
1089                         cc.logger.Infow("Disconnect & ban " + string(clientConn.UserName))
1090
1091                         res = append(res, *NewTransaction(
1092                                 tranServerMsg,
1093                                 clientConn.ID,
1094                                 NewField(fieldData, []byte("You are permanently banned on this server")),
1095                                 NewField(fieldChatOptions, []byte{0, 0}),
1096                         ))
1097
1098                         cc.Server.banList[strings.Split(clientConn.RemoteAddr, ":")[0]] = nil
1099                         cc.Server.writeBanList()
1100                 }
1101         }
1102
1103         // TODO: remove this awful hack
1104         go func() {
1105                 time.Sleep(1 * time.Second)
1106                 clientConn.Disconnect()
1107         }()
1108
1109         return append(res, cc.NewReply(t)), err
1110 }
1111
1112 // HandleGetNewsCatNameList returns a list of news categories for a path
1113 // Fields used in the request:
1114 // 325  News path       (Optional)
1115 func HandleGetNewsCatNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1116         if !cc.Authorize(accessNewsReadArt) {
1117                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1118                 return res, err
1119         }
1120
1121         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1122         cats := cc.Server.GetNewsCatByPath(pathStrs)
1123
1124         // To store the keys in slice in sorted order
1125         keys := make([]string, len(cats))
1126         i := 0
1127         for k := range cats {
1128                 keys[i] = k
1129                 i++
1130         }
1131         sort.Strings(keys)
1132
1133         var fieldData []Field
1134         for _, k := range keys {
1135                 cat := cats[k]
1136                 b, _ := cat.MarshalBinary()
1137                 fieldData = append(fieldData, NewField(
1138                         fieldNewsCatListData15,
1139                         b,
1140                 ))
1141         }
1142
1143         res = append(res, cc.NewReply(t, fieldData...))
1144         return res, err
1145 }
1146
1147 func HandleNewNewsCat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1148         if !cc.Authorize(accessNewsCreateCat) {
1149                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news categories."))
1150                 return res, err
1151         }
1152
1153         name := string(t.GetField(fieldNewsCatName).Data)
1154         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1155
1156         cats := cc.Server.GetNewsCatByPath(pathStrs)
1157         cats[name] = NewsCategoryListData15{
1158                 Name:     name,
1159                 Type:     []byte{0, 3},
1160                 Articles: map[uint32]*NewsArtData{},
1161                 SubCats:  make(map[string]NewsCategoryListData15),
1162         }
1163
1164         if err := cc.Server.writeThreadedNews(); err != nil {
1165                 return res, err
1166         }
1167         res = append(res, cc.NewReply(t))
1168         return res, err
1169 }
1170
1171 // Fields used in the request:
1172 // 322  News category name
1173 // 325  News path
1174 func HandleNewNewsFldr(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1175         if !cc.Authorize(accessNewsCreateFldr) {
1176                 res = append(res, cc.NewErrReply(t, "You are not allowed to create news folders."))
1177                 return res, err
1178         }
1179
1180         name := string(t.GetField(fieldFileName).Data)
1181         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1182
1183         cc.logger.Infof("Creating new news folder %s", name)
1184
1185         cats := cc.Server.GetNewsCatByPath(pathStrs)
1186         cats[name] = NewsCategoryListData15{
1187                 Name:     name,
1188                 Type:     []byte{0, 2},
1189                 Articles: map[uint32]*NewsArtData{},
1190                 SubCats:  make(map[string]NewsCategoryListData15),
1191         }
1192         if err := cc.Server.writeThreadedNews(); err != nil {
1193                 return res, err
1194         }
1195         res = append(res, cc.NewReply(t))
1196         return res, err
1197 }
1198
1199 // Fields used in the request:
1200 // 325  News path       Optional
1201 //
1202 // Reply fields:
1203 // 321  News article list data  Optional
1204 func HandleGetNewsArtNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1205         if !cc.Authorize(accessNewsReadArt) {
1206                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1207                 return res, err
1208         }
1209         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1210
1211         var cat NewsCategoryListData15
1212         cats := cc.Server.ThreadedNews.Categories
1213
1214         for _, fp := range pathStrs {
1215                 cat = cats[fp]
1216                 cats = cats[fp].SubCats
1217         }
1218
1219         nald := cat.GetNewsArtListData()
1220
1221         res = append(res, cc.NewReply(t, NewField(fieldNewsArtListData, nald.Payload())))
1222         return res, err
1223 }
1224
1225 func HandleGetNewsArtData(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1226         if !cc.Authorize(accessNewsReadArt) {
1227                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1228                 return res, err
1229         }
1230
1231         // Request fields
1232         // 325  News fp
1233         // 326  News article ID
1234         // 327  News article data flavor
1235
1236         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1237
1238         var cat NewsCategoryListData15
1239         cats := cc.Server.ThreadedNews.Categories
1240
1241         for _, fp := range pathStrs {
1242                 cat = cats[fp]
1243                 cats = cats[fp].SubCats
1244         }
1245         newsArtID := t.GetField(fieldNewsArtID).Data
1246
1247         convertedArtID := binary.BigEndian.Uint16(newsArtID)
1248
1249         art := cat.Articles[uint32(convertedArtID)]
1250         if art == nil {
1251                 res = append(res, cc.NewReply(t))
1252                 return res, err
1253         }
1254
1255         // Reply fields
1256         // 328  News article title
1257         // 329  News article poster
1258         // 330  News article date
1259         // 331  Previous article ID
1260         // 332  Next article ID
1261         // 335  Parent article ID
1262         // 336  First child article ID
1263         // 327  News article data flavor        "Should be “text/plain”
1264         // 333  News article data       Optional (if data flavor is “text/plain”)
1265
1266         res = append(res, cc.NewReply(t,
1267                 NewField(fieldNewsArtTitle, []byte(art.Title)),
1268                 NewField(fieldNewsArtPoster, []byte(art.Poster)),
1269                 NewField(fieldNewsArtDate, art.Date),
1270                 NewField(fieldNewsArtPrevArt, art.PrevArt),
1271                 NewField(fieldNewsArtNextArt, art.NextArt),
1272                 NewField(fieldNewsArtParentArt, art.ParentArt),
1273                 NewField(fieldNewsArt1stChildArt, art.FirstChildArt),
1274                 NewField(fieldNewsArtDataFlav, []byte("text/plain")),
1275                 NewField(fieldNewsArtData, []byte(art.Data)),
1276         ))
1277         return res, err
1278 }
1279
1280 // HandleDelNewsItem deletes an existing threaded news folder or category from the server.
1281 // Fields used in the request:
1282 // 325  News path
1283 // Fields used in the reply:
1284 // None
1285 func HandleDelNewsItem(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1286         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1287
1288         cats := cc.Server.ThreadedNews.Categories
1289         delName := pathStrs[len(pathStrs)-1]
1290         if len(pathStrs) > 1 {
1291                 for _, fp := range pathStrs[0 : len(pathStrs)-1] {
1292                         cats = cats[fp].SubCats
1293                 }
1294         }
1295
1296         if bytes.Compare(cats[delName].Type, []byte{0, 3}) == 0 {
1297                 if !cc.Authorize(accessNewsDeleteCat) {
1298                         return append(res, cc.NewErrReply(t, "You are not allowed to delete news categories.")), nil
1299                 }
1300         } else {
1301                 if !cc.Authorize(accessNewsDeleteFldr) {
1302                         return append(res, cc.NewErrReply(t, "You are not allowed to delete news folders.")), nil
1303                 }
1304         }
1305
1306         delete(cats, delName)
1307
1308         if err := cc.Server.writeThreadedNews(); err != nil {
1309                 return res, err
1310         }
1311
1312         return append(res, cc.NewReply(t)), nil
1313 }
1314
1315 func HandleDelNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1316         if !cc.Authorize(accessNewsDeleteArt) {
1317                 res = append(res, cc.NewErrReply(t, "You are not allowed to delete news articles."))
1318                 return res, err
1319         }
1320
1321         // Request Fields
1322         // 325  News path
1323         // 326  News article ID
1324         // 337  News article – recursive delete       Delete child articles (1) or not (0)
1325         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1326         ID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1327
1328         // TODO: Delete recursive
1329         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1330
1331         catName := pathStrs[len(pathStrs)-1]
1332         cat := cats[catName]
1333
1334         delete(cat.Articles, uint32(ID))
1335
1336         cats[catName] = cat
1337         if err := cc.Server.writeThreadedNews(); err != nil {
1338                 return res, err
1339         }
1340
1341         res = append(res, cc.NewReply(t))
1342         return res, err
1343 }
1344
1345 // Request fields
1346 // 325  News path
1347 // 326  News article ID                                                 ID of the parent article?
1348 // 328  News article title
1349 // 334  News article flags
1350 // 327  News article data flavor                Currently “text/plain”
1351 // 333  News article data
1352 func HandlePostNewsArt(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1353         if !cc.Authorize(accessNewsPostArt) {
1354                 res = append(res, cc.NewErrReply(t, "You are not allowed to post news articles."))
1355                 return res, err
1356         }
1357
1358         pathStrs := ReadNewsPath(t.GetField(fieldNewsPath).Data)
1359         cats := cc.Server.GetNewsCatByPath(pathStrs[:len(pathStrs)-1])
1360
1361         catName := pathStrs[len(pathStrs)-1]
1362         cat := cats[catName]
1363
1364         newArt := NewsArtData{
1365                 Title:         string(t.GetField(fieldNewsArtTitle).Data),
1366                 Poster:        string(cc.UserName),
1367                 Date:          toHotlineTime(time.Now()),
1368                 PrevArt:       []byte{0, 0, 0, 0},
1369                 NextArt:       []byte{0, 0, 0, 0},
1370                 ParentArt:     append([]byte{0, 0}, t.GetField(fieldNewsArtID).Data...),
1371                 FirstChildArt: []byte{0, 0, 0, 0},
1372                 DataFlav:      []byte("text/plain"),
1373                 Data:          string(t.GetField(fieldNewsArtData).Data),
1374         }
1375
1376         var keys []int
1377         for k := range cat.Articles {
1378                 keys = append(keys, int(k))
1379         }
1380
1381         nextID := uint32(1)
1382         if len(keys) > 0 {
1383                 sort.Ints(keys)
1384                 prevID := uint32(keys[len(keys)-1])
1385                 nextID = prevID + 1
1386
1387                 binary.BigEndian.PutUint32(newArt.PrevArt, prevID)
1388
1389                 // Set next article ID
1390                 binary.BigEndian.PutUint32(cat.Articles[prevID].NextArt, nextID)
1391         }
1392
1393         // Update parent article with first child reply
1394         parentID := binary.BigEndian.Uint16(t.GetField(fieldNewsArtID).Data)
1395         if parentID != 0 {
1396                 parentArt := cat.Articles[uint32(parentID)]
1397
1398                 if bytes.Equal(parentArt.FirstChildArt, []byte{0, 0, 0, 0}) {
1399                         binary.BigEndian.PutUint32(parentArt.FirstChildArt, nextID)
1400                 }
1401         }
1402
1403         cat.Articles[nextID] = &newArt
1404
1405         cats[catName] = cat
1406         if err := cc.Server.writeThreadedNews(); err != nil {
1407                 return res, err
1408         }
1409
1410         res = append(res, cc.NewReply(t))
1411         return res, err
1412 }
1413
1414 // HandleGetMsgs returns the flat news data
1415 func HandleGetMsgs(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1416         if !cc.Authorize(accessNewsReadArt) {
1417                 res = append(res, cc.NewErrReply(t, "You are not allowed to read news."))
1418                 return res, err
1419         }
1420
1421         res = append(res, cc.NewReply(t, NewField(fieldData, cc.Server.FlatNews)))
1422
1423         return res, err
1424 }
1425
1426 func HandleDownloadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1427         if !cc.Authorize(accessDownloadFile) {
1428                 res = append(res, cc.NewErrReply(t, "You are not allowed to download files."))
1429                 return res, err
1430         }
1431
1432         fileName := t.GetField(fieldFileName).Data
1433         filePath := t.GetField(fieldFilePath).Data
1434         resumeData := t.GetField(fieldFileResumeData).Data
1435
1436         var dataOffset int64
1437         var frd FileResumeData
1438         if resumeData != nil {
1439                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1440                         return res, err
1441                 }
1442                 // TODO: handle rsrc fork offset
1443                 dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
1444         }
1445
1446         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1447         if err != nil {
1448                 return res, err
1449         }
1450
1451         hlFile, err := newFileWrapper(cc.Server.FS, fullFilePath, dataOffset)
1452         if err != nil {
1453                 return res, err
1454         }
1455
1456         xferSize := hlFile.ffo.TransferSize(0)
1457
1458         ft := cc.newFileTransfer(FileDownload, fileName, filePath, xferSize)
1459
1460         // TODO: refactor to remove this
1461         if resumeData != nil {
1462                 var frd FileResumeData
1463                 if err := frd.UnmarshalBinary(t.GetField(fieldFileResumeData).Data); err != nil {
1464                         return res, err
1465                 }
1466                 ft.fileResumeData = &frd
1467         }
1468
1469         // Optional field for when a HL v1.5+ client requests file preview
1470         // Used only for TEXT, JPEG, GIFF, BMP or PICT files
1471         // The value will always be 2
1472         if t.GetField(fieldFileTransferOptions).Data != nil {
1473                 ft.options = t.GetField(fieldFileTransferOptions).Data
1474                 xferSize = hlFile.ffo.FlatFileDataForkHeader.DataSize[:]
1475         }
1476
1477         res = append(res, cc.NewReply(t,
1478                 NewField(fieldRefNum, ft.refNum[:]),
1479                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1480                 NewField(fieldTransferSize, xferSize),
1481                 NewField(fieldFileSize, hlFile.ffo.FlatFileDataForkHeader.DataSize[:]),
1482         ))
1483
1484         return res, err
1485 }
1486
1487 // Download all files from the specified folder and sub-folders
1488 func HandleDownloadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1489         if !cc.Authorize(accessDownloadFile) {
1490                 res = append(res, cc.NewErrReply(t, "You are not allowed to download folders."))
1491                 return res, err
1492         }
1493
1494         fullFilePath, err := readPath(cc.Server.Config.FileRoot, t.GetField(fieldFilePath).Data, t.GetField(fieldFileName).Data)
1495         if err != nil {
1496                 return res, err
1497         }
1498
1499         transferSize, err := CalcTotalSize(fullFilePath)
1500         if err != nil {
1501                 return res, err
1502         }
1503         itemCount, err := CalcItemCount(fullFilePath)
1504         if err != nil {
1505                 return res, err
1506         }
1507
1508         fileTransfer := cc.newFileTransfer(FolderDownload, t.GetField(fieldFileName).Data, t.GetField(fieldFilePath).Data, transferSize)
1509
1510         var fp FilePath
1511         _, err = fp.Write(t.GetField(fieldFilePath).Data)
1512         if err != nil {
1513                 return res, err
1514         }
1515
1516         res = append(res, cc.NewReply(t,
1517                 NewField(fieldRefNum, fileTransfer.ReferenceNumber),
1518                 NewField(fieldTransferSize, transferSize),
1519                 NewField(fieldFolderItemCount, itemCount),
1520                 NewField(fieldWaitingCount, []byte{0x00, 0x00}), // TODO: Implement waiting count
1521         ))
1522         return res, err
1523 }
1524
1525 // Upload all files from the local folder and its subfolders to the specified path on the server
1526 // Fields used in the request
1527 // 201  File name
1528 // 202  File path
1529 // 108  transfer size   Total size of all items in the folder
1530 // 220  Folder item count
1531 // 204  File transfer options   "Optional Currently set to 1" (TODO: ??)
1532 func HandleUploadFolder(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1533         var fp FilePath
1534         if t.GetField(fieldFilePath).Data != nil {
1535                 if _, err = fp.Write(t.GetField(fieldFilePath).Data); err != nil {
1536                         return res, err
1537                 }
1538         }
1539
1540         // Handle special cases for Upload and Drop Box folders
1541         if !cc.Authorize(accessUploadAnywhere) {
1542                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1543                         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))))
1544                         return res, err
1545                 }
1546         }
1547
1548         fileTransfer := cc.newFileTransfer(FolderUpload,
1549                 t.GetField(fieldFileName).Data,
1550                 t.GetField(fieldFilePath).Data,
1551                 t.GetField(fieldTransferSize).Data,
1552         )
1553
1554         fileTransfer.FolderItemCount = t.GetField(fieldFolderItemCount).Data
1555
1556         res = append(res, cc.NewReply(t, NewField(fieldRefNum, fileTransfer.ReferenceNumber)))
1557         return res, err
1558 }
1559
1560 // HandleUploadFile
1561 // Fields used in the request:
1562 // 201  File name
1563 // 202  File path
1564 // 204  File transfer options   "Optional
1565 // Used only to resume download, currently has value 2"
1566 // 108  File transfer size      "Optional used if download is not resumed"
1567 func HandleUploadFile(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1568         if !cc.Authorize(accessUploadFile) {
1569                 res = append(res, cc.NewErrReply(t, "You are not allowed to upload files."))
1570                 return res, err
1571         }
1572
1573         fileName := t.GetField(fieldFileName).Data
1574         filePath := t.GetField(fieldFilePath).Data
1575         transferOptions := t.GetField(fieldFileTransferOptions).Data
1576         transferSize := t.GetField(fieldTransferSize).Data // not sent for resume
1577
1578         var fp FilePath
1579         if filePath != nil {
1580                 if _, err = fp.Write(filePath); err != nil {
1581                         return res, err
1582                 }
1583         }
1584
1585         // Handle special cases for Upload and Drop Box folders
1586         if !cc.Authorize(accessUploadAnywhere) {
1587                 if !fp.IsUploadDir() && !fp.IsDropbox() {
1588                         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))))
1589                         return res, err
1590                 }
1591         }
1592         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1593         if err != nil {
1594                 return res, err
1595         }
1596
1597         if _, err := cc.Server.FS.Stat(fullFilePath); err == nil {
1598                 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))))
1599                 return res, err
1600         }
1601
1602         ft := cc.newFileTransfer(FileUpload, fileName, filePath, transferSize)
1603
1604         replyT := cc.NewReply(t, NewField(fieldRefNum, ft.ReferenceNumber))
1605
1606         // client has requested to resume a partially transferred file
1607         if transferOptions != nil {
1608
1609                 fileInfo, err := cc.Server.FS.Stat(fullFilePath + incompleteFileSuffix)
1610                 if err != nil {
1611                         return res, err
1612                 }
1613
1614                 offset := make([]byte, 4)
1615                 binary.BigEndian.PutUint32(offset, uint32(fileInfo.Size()))
1616
1617                 fileResumeData := NewFileResumeData([]ForkInfoList{
1618                         *NewForkInfoList(offset),
1619                 })
1620
1621                 b, _ := fileResumeData.BinaryMarshal()
1622
1623                 ft.TransferSize = offset
1624
1625                 replyT.Fields = append(replyT.Fields, NewField(fieldFileResumeData, b))
1626         }
1627
1628         res = append(res, replyT)
1629         return res, err
1630 }
1631
1632 func HandleSetClientUserInfo(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1633         if len(t.GetField(fieldUserIconID).Data) == 4 {
1634                 cc.Icon = t.GetField(fieldUserIconID).Data[2:]
1635         } else {
1636                 cc.Icon = t.GetField(fieldUserIconID).Data
1637         }
1638         if cc.Authorize(accessAnyName) {
1639                 cc.UserName = t.GetField(fieldUserName).Data
1640         }
1641
1642         // the options field is only passed by the client versions > 1.2.3.
1643         options := t.GetField(fieldOptions).Data
1644         if options != nil {
1645                 optBitmap := big.NewInt(int64(binary.BigEndian.Uint16(options)))
1646                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(cc.Flags)))
1647
1648                 flagBitmap.SetBit(flagBitmap, userFlagRefusePM, optBitmap.Bit(refusePM))
1649                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1650
1651                 flagBitmap.SetBit(flagBitmap, userFLagRefusePChat, optBitmap.Bit(refuseChat))
1652                 binary.BigEndian.PutUint16(cc.Flags, uint16(flagBitmap.Int64()))
1653
1654                 // Check auto response
1655                 if optBitmap.Bit(autoResponse) == 1 {
1656                         cc.AutoReply = t.GetField(fieldAutomaticResponse).Data
1657                 } else {
1658                         cc.AutoReply = []byte{}
1659                 }
1660         }
1661
1662         for _, c := range sortedClients(cc.Server.Clients) {
1663                 res = append(res, *NewTransaction(
1664                         tranNotifyChangeUser,
1665                         c.ID,
1666                         NewField(fieldUserID, *cc.ID),
1667                         NewField(fieldUserIconID, cc.Icon),
1668                         NewField(fieldUserFlags, cc.Flags),
1669                         NewField(fieldUserName, cc.UserName),
1670                 ))
1671         }
1672
1673         return res, err
1674 }
1675
1676 // HandleKeepAlive responds to keepalive transactions with an empty reply
1677 // * HL 1.9.2 Client sends keepalive msg every 3 minutes
1678 // * HL 1.2.3 Client doesn't send keepalives
1679 func HandleKeepAlive(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1680         res = append(res, cc.NewReply(t))
1681
1682         return res, err
1683 }
1684
1685 func HandleGetFileNameList(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1686         fullPath, err := readPath(
1687                 cc.Server.Config.FileRoot,
1688                 t.GetField(fieldFilePath).Data,
1689                 nil,
1690         )
1691         if err != nil {
1692                 return res, err
1693         }
1694
1695         var fp FilePath
1696         if t.GetField(fieldFilePath).Data != nil {
1697                 if _, err = fp.Write(t.GetField(fieldFilePath).Data); err != nil {
1698                         return res, err
1699                 }
1700         }
1701
1702         // Handle special case for drop box folders
1703         if fp.IsDropbox() && !cc.Authorize(accessViewDropBoxes) {
1704                 res = append(res, cc.NewErrReply(t, "You are not allowed to view drop boxes."))
1705                 return res, err
1706         }
1707
1708         fileNames, err := getFileNameList(fullPath, cc.Server.Config.IgnoreFiles)
1709         if err != nil {
1710                 return res, err
1711         }
1712
1713         res = append(res, cc.NewReply(t, fileNames...))
1714
1715         return res, err
1716 }
1717
1718 // =================================
1719 //     Hotline private chat flow
1720 // =================================
1721 // 1. ClientA sends tranInviteNewChat to server with user ID to invite
1722 // 2. Server creates new ChatID
1723 // 3. Server sends tranInviteToChat to invitee
1724 // 4. Server replies to ClientA with new Chat ID
1725 //
1726 // A dialog box pops up in the invitee client with options to accept or decline the invitation.
1727 // If Accepted is clicked:
1728 // 1. ClientB sends tranJoinChat with fieldChatID
1729
1730 // HandleInviteNewChat invites users to new private chat
1731 func HandleInviteNewChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1732         if !cc.Authorize(accessOpenChat) {
1733                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1734                 return res, err
1735         }
1736
1737         // Client to Invite
1738         targetID := t.GetField(fieldUserID).Data
1739         newChatID := cc.Server.NewPrivateChat(cc)
1740
1741         // Check if target user has "Refuse private chat" flag
1742         binary.BigEndian.Uint16(targetID)
1743         targetClient := cc.Server.Clients[binary.BigEndian.Uint16(targetID)]
1744
1745         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(targetClient.Flags)))
1746         if flagBitmap.Bit(userFLagRefusePChat) == 1 {
1747                 res = append(res,
1748                         *NewTransaction(
1749                                 tranServerMsg,
1750                                 cc.ID,
1751                                 NewField(fieldData, []byte(string(targetClient.UserName)+" does not accept private chats.")),
1752                                 NewField(fieldUserName, targetClient.UserName),
1753                                 NewField(fieldUserID, *targetClient.ID),
1754                                 NewField(fieldOptions, []byte{0, 2}),
1755                         ),
1756                 )
1757         } else {
1758                 res = append(res,
1759                         *NewTransaction(
1760                                 tranInviteToChat,
1761                                 &targetID,
1762                                 NewField(fieldChatID, newChatID),
1763                                 NewField(fieldUserName, cc.UserName),
1764                                 NewField(fieldUserID, *cc.ID),
1765                         ),
1766                 )
1767         }
1768
1769         res = append(res,
1770                 cc.NewReply(t,
1771                         NewField(fieldChatID, newChatID),
1772                         NewField(fieldUserName, cc.UserName),
1773                         NewField(fieldUserID, *cc.ID),
1774                         NewField(fieldUserIconID, cc.Icon),
1775                         NewField(fieldUserFlags, cc.Flags),
1776                 ),
1777         )
1778
1779         return res, err
1780 }
1781
1782 func HandleInviteToChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1783         if !cc.Authorize(accessOpenChat) {
1784                 res = append(res, cc.NewErrReply(t, "You are not allowed to request private chat."))
1785                 return res, err
1786         }
1787
1788         // Client to Invite
1789         targetID := t.GetField(fieldUserID).Data
1790         chatID := t.GetField(fieldChatID).Data
1791
1792         res = append(res,
1793                 *NewTransaction(
1794                         tranInviteToChat,
1795                         &targetID,
1796                         NewField(fieldChatID, chatID),
1797                         NewField(fieldUserName, cc.UserName),
1798                         NewField(fieldUserID, *cc.ID),
1799                 ),
1800         )
1801         res = append(res,
1802                 cc.NewReply(
1803                         t,
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         return res, err
1813 }
1814
1815 func HandleRejectChatInvite(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1816         chatID := t.GetField(fieldChatID).Data
1817         chatInt := binary.BigEndian.Uint32(chatID)
1818
1819         privChat := cc.Server.PrivateChats[chatInt]
1820
1821         resMsg := append(cc.UserName, []byte(" declined invitation to chat")...)
1822
1823         for _, c := range sortedClients(privChat.ClientConn) {
1824                 res = append(res,
1825                         *NewTransaction(
1826                                 tranChatMsg,
1827                                 c.ID,
1828                                 NewField(fieldChatID, chatID),
1829                                 NewField(fieldData, resMsg),
1830                         ),
1831                 )
1832         }
1833
1834         return res, err
1835 }
1836
1837 // HandleJoinChat is sent from a v1.8+ Hotline client when the joins a private chat
1838 // Fields used in the reply:
1839 // * 115        Chat subject
1840 // * 300        User name with info (Optional)
1841 // * 300        (more user names with info)
1842 func HandleJoinChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1843         chatID := t.GetField(fieldChatID).Data
1844         chatInt := binary.BigEndian.Uint32(chatID)
1845
1846         privChat := cc.Server.PrivateChats[chatInt]
1847
1848         // Send tranNotifyChatChangeUser to current members of the chat to inform of new user
1849         for _, c := range sortedClients(privChat.ClientConn) {
1850                 res = append(res,
1851                         *NewTransaction(
1852                                 tranNotifyChatChangeUser,
1853                                 c.ID,
1854                                 NewField(fieldChatID, chatID),
1855                                 NewField(fieldUserName, cc.UserName),
1856                                 NewField(fieldUserID, *cc.ID),
1857                                 NewField(fieldUserIconID, cc.Icon),
1858                                 NewField(fieldUserFlags, cc.Flags),
1859                         ),
1860                 )
1861         }
1862
1863         privChat.ClientConn[cc.uint16ID()] = cc
1864
1865         replyFields := []Field{NewField(fieldChatSubject, []byte(privChat.Subject))}
1866         for _, c := range sortedClients(privChat.ClientConn) {
1867                 user := User{
1868                         ID:    *c.ID,
1869                         Icon:  c.Icon,
1870                         Flags: c.Flags,
1871                         Name:  string(c.UserName),
1872                 }
1873
1874                 replyFields = append(replyFields, NewField(fieldUsernameWithInfo, user.Payload()))
1875         }
1876
1877         res = append(res, cc.NewReply(t, replyFields...))
1878         return res, err
1879 }
1880
1881 // HandleLeaveChat is sent from a v1.8+ Hotline client when the user exits a private chat
1882 // Fields used in the request:
1883 //      * 114   fieldChatID
1884 // Reply is not expected.
1885 func HandleLeaveChat(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1886         chatID := t.GetField(fieldChatID).Data
1887         chatInt := binary.BigEndian.Uint32(chatID)
1888
1889         privChat, ok := cc.Server.PrivateChats[chatInt]
1890         if !ok {
1891                 return res, nil
1892         }
1893
1894         delete(privChat.ClientConn, cc.uint16ID())
1895
1896         // Notify members of the private chat that the user has left
1897         for _, c := range sortedClients(privChat.ClientConn) {
1898                 res = append(res,
1899                         *NewTransaction(
1900                                 tranNotifyChatDeleteUser,
1901                                 c.ID,
1902                                 NewField(fieldChatID, chatID),
1903                                 NewField(fieldUserID, *cc.ID),
1904                         ),
1905                 )
1906         }
1907
1908         return res, err
1909 }
1910
1911 // HandleSetChatSubject is sent from a v1.8+ Hotline client when the user sets a private chat subject
1912 // Fields used in the request:
1913 // * 114        Chat ID
1914 // * 115        Chat subject    Chat subject string
1915 // Reply is not expected.
1916 func HandleSetChatSubject(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1917         chatID := t.GetField(fieldChatID).Data
1918         chatInt := binary.BigEndian.Uint32(chatID)
1919
1920         privChat := cc.Server.PrivateChats[chatInt]
1921         privChat.Subject = string(t.GetField(fieldChatSubject).Data)
1922
1923         for _, c := range sortedClients(privChat.ClientConn) {
1924                 res = append(res,
1925                         *NewTransaction(
1926                                 tranNotifyChatSubject,
1927                                 c.ID,
1928                                 NewField(fieldChatID, chatID),
1929                                 NewField(fieldChatSubject, t.GetField(fieldChatSubject).Data),
1930                         ),
1931                 )
1932         }
1933
1934         return res, err
1935 }
1936
1937 // HandleMakeAlias makes a filer alias using the specified path.
1938 // Fields used in the request:
1939 // 201  File name
1940 // 202  File path
1941 // 212  File new path   Destination path
1942 //
1943 // Fields used in the reply:
1944 // None
1945 func HandleMakeAlias(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1946         if !cc.Authorize(accessMakeAlias) {
1947                 res = append(res, cc.NewErrReply(t, "You are not allowed to make aliases."))
1948                 return res, err
1949         }
1950         fileName := t.GetField(fieldFileName).Data
1951         filePath := t.GetField(fieldFilePath).Data
1952         fileNewPath := t.GetField(fieldFileNewPath).Data
1953
1954         fullFilePath, err := readPath(cc.Server.Config.FileRoot, filePath, fileName)
1955         if err != nil {
1956                 return res, err
1957         }
1958
1959         fullNewFilePath, err := readPath(cc.Server.Config.FileRoot, fileNewPath, fileName)
1960         if err != nil {
1961                 return res, err
1962         }
1963
1964         cc.logger.Debugw("Make alias", "src", fullFilePath, "dst", fullNewFilePath)
1965
1966         if err := cc.Server.FS.Symlink(fullFilePath, fullNewFilePath); err != nil {
1967                 res = append(res, cc.NewErrReply(t, "Error creating alias"))
1968                 return res, nil
1969         }
1970
1971         res = append(res, cc.NewReply(t))
1972         return res, err
1973 }
1974
1975 // HandleDownloadBanner handles requests for a new banner from the server
1976 // Fields used in the request:
1977 // None
1978 // Fields used in the reply:
1979 // 107  fieldRefNum                     Used later for transfer
1980 // 108  fieldTransferSize       Size of data to be downloaded
1981 func HandleDownloadBanner(cc *ClientConn, t *Transaction) (res []Transaction, err error) {
1982         fi, err := cc.Server.FS.Stat(filepath.Join(cc.Server.ConfigDir, cc.Server.Config.BannerFile))
1983         if err != nil {
1984                 return res, err
1985         }
1986
1987         ft := cc.newFileTransfer(bannerDownload, []byte{}, []byte{}, make([]byte, 4))
1988
1989         binary.BigEndian.PutUint32(ft.TransferSize, uint32(fi.Size()))
1990
1991         res = append(res, cc.NewReply(t,
1992                 NewField(fieldRefNum, ft.refNum[:]),
1993                 NewField(fieldTransferSize, ft.TransferSize),
1994         ))
1995
1996         return res, err
1997 }