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

   1 package hotline
   2
   3 import (
   4         "bufio"
   5         "bytes"
   6         "context"
   7         "embed"
   8         "encoding/binary"
   9         "errors"
  10         "fmt"
  11         "github.com/gdamore/tcell/v2"
  12         "github.com/rivo/tview"
  13         "gopkg.in/yaml.v3"
  14         "log/slog"
  15         "math/big"
  16         "math/rand"
  17         "net"
  18         "os"
  19         "strings"
  20         "time"
  21 )
  22
  23 const (
  24         trackerListPage = "trackerList"
  25         serverUIPage    = "serverUI"
  26 )
  27
  28 //go:embed banners/*.txt
  29 var bannerDir embed.FS
  30
  31 type Bookmark struct {
  32         Name     string `yaml:"Name"`
  33         Addr     string `yaml:"Addr"`
  34         Login    string `yaml:"Login"`
  35         Password string `yaml:"Password"`
  36 }
  37
  38 type ClientPrefs struct {
  39         Username   string     `yaml:"Username"`
  40         IconID     int        `yaml:"IconID"`
  41         Bookmarks  []Bookmark `yaml:"Bookmarks"`
  42         Tracker    string     `yaml:"Tracker"`
  43         EnableBell bool       `yaml:"EnableBell"`
  44 }
  45
  46 func (cp *ClientPrefs) IconBytes() []byte {
  47         iconBytes := make([]byte, 2)
  48         binary.BigEndian.PutUint16(iconBytes, uint16(cp.IconID))
  49         return iconBytes
  50 }
  51
  52 func (cp *ClientPrefs) AddBookmark(name, addr, login, pass string) {
  53         cp.Bookmarks = append(cp.Bookmarks, Bookmark{Addr: addr, Login: login, Password: pass})
  54 }
  55
  56 func readConfig(cfgPath string) (*ClientPrefs, error) {
  57         fh, err := os.Open(cfgPath)
  58         if err != nil {
  59                 return nil, err
  60         }
  61
  62         prefs := ClientPrefs{}
  63         decoder := yaml.NewDecoder(fh)
  64         if err := decoder.Decode(&prefs); err != nil {
  65                 return nil, err
  66         }
  67         return &prefs, nil
  68 }
  69
  70 type Client struct {
  71         cfgPath     string
  72         DebugBuf    *DebugBuffer
  73         Connection  net.Conn
  74         UserAccess  []byte
  75         filePath    []string
  76         UserList    []User
  77         Logger      *slog.Logger
  78         activeTasks map[uint32]*Transaction
  79         serverName  string
  80
  81         Pref *ClientPrefs
  82
  83         Handlers map[uint16]ClientHandler
  84
  85         UI *UI
  86
  87         Inbox chan *Transaction
  88 }
  89
  90 type ClientHandler func(context.Context, *Client, *Transaction) ([]Transaction, error)
  91
  92 func (c *Client) HandleFunc(transactionID uint16, handler ClientHandler) {
  93         c.Handlers[transactionID] = handler
  94 }
  95
  96 func NewClient(username string, logger *slog.Logger) *Client {
  97         c := &Client{
  98                 Logger:      logger,
  99                 activeTasks: make(map[uint32]*Transaction),
 100                 Handlers:    make(map[uint16]ClientHandler),
 101         }
 102         c.Pref = &ClientPrefs{Username: username}
 103
 104         return c
 105 }
 106
 107 func NewUIClient(cfgPath string, logger *slog.Logger) *Client {
 108         c := &Client{
 109                 cfgPath:     cfgPath,
 110                 Logger:      logger,
 111                 activeTasks: make(map[uint32]*Transaction),
 112                 Handlers:    clientHandlers,
 113         }
 114         c.UI = NewUI(c)
 115
 116         prefs, err := readConfig(cfgPath)
 117         if err != nil {
 118                 logger.Error(fmt.Sprintf("unable to read config file %s\n", cfgPath))
 119                 os.Exit(1)
 120         }
 121         c.Pref = prefs
 122
 123         return c
 124 }
 125
 126 // DebugBuffer wraps a *tview.TextView and adds a Sync() method to make it available as a Zap logger
 127 type DebugBuffer struct {
 128         TextView *tview.TextView
 129 }
 130
 131 func (db *DebugBuffer) Write(p []byte) (int, error) {
 132         return db.TextView.Write(p)
 133 }
 134
 135 // Sync is a noop function that dataFile to satisfy the zapcore.WriteSyncer interface
 136 func (db *DebugBuffer) Sync() error {
 137         return nil
 138 }
 139
 140 func randomBanner() string {
 141         rand.Seed(time.Now().UnixNano())
 142
 143         bannerFiles, _ := bannerDir.ReadDir("banners")
 144         file, _ := bannerDir.ReadFile("banners/" + bannerFiles[rand.Intn(len(bannerFiles))].Name())
 145
 146         return fmt.Sprintf("\n\n\nWelcome to...\n\n[red::b]%s[-:-:-]\n\n", file)
 147 }
 148
 149 type ClientTransaction struct {
 150         Name    string
 151         Handler func(*Client, *Transaction) ([]Transaction, error)
 152 }
 153
 154 func (ch ClientTransaction) Handle(cc *Client, t *Transaction) ([]Transaction, error) {
 155         return ch.Handler(cc, t)
 156 }
 157
 158 type ClientTHandler interface {
 159         Handle(*Client, *Transaction) ([]Transaction, error)
 160 }
 161
 162 var clientHandlers = map[uint16]ClientHandler{
 163         TranChatMsg:          handleClientChatMsg,
 164         TranLogin:            handleClientTranLogin,
 165         TranShowAgreement:    handleClientTranShowAgreement,
 166         TranUserAccess:       handleClientTranUserAccess,
 167         TranGetUserNameList:  handleClientGetUserNameList,
 168         TranNotifyChangeUser: handleNotifyChangeUser,
 169         TranNotifyDeleteUser: handleNotifyDeleteUser,
 170         TranGetMsgs:          handleGetMsgs,
 171         TranGetFileNameList:  handleGetFileNameList,
 172         TranServerMsg:        handleTranServerMsg,
 173         TranKeepAlive: func(ctx context.Context, client *Client, transaction *Transaction) (t []Transaction, err error) {
 174                 return t, err
 175         },
 176 }
 177
 178 func handleTranServerMsg(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 179         now := time.Now().Format(time.RFC850)
 180
 181         msg := strings.ReplaceAll(string(t.GetField(FieldData).Data), "\r", "\n")
 182         msg += "\n\nAt " + now
 183         title := fmt.Sprintf("| Private Message From:   %s |", t.GetField(FieldUserName).Data)
 184
 185         msgBox := tview.NewTextView().SetScrollable(true)
 186         msgBox.SetText(msg).SetBackgroundColor(tcell.ColorDarkSlateBlue)
 187         msgBox.SetTitle(title).SetBorder(true)
 188         msgBox.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
 189                 switch event.Key() {
 190                 case tcell.KeyEscape:
 191                         c.UI.Pages.RemovePage("serverMsgModal" + now)
 192                 }
 193                 return event
 194         })
 195
 196         centeredFlex := tview.NewFlex().
 197                 AddItem(nil, 0, 1, false).
 198                 AddItem(tview.NewFlex().SetDirection(tview.FlexRow).
 199                         AddItem(nil, 0, 1, false).
 200                         AddItem(msgBox, 0, 2, true).
 201                         AddItem(nil, 0, 1, false), 0, 2, true).
 202                 AddItem(nil, 0, 1, false)
 203
 204         c.UI.Pages.AddPage("serverMsgModal"+now, centeredFlex, true, true)
 205         c.UI.App.Draw() // TODO: errModal doesn't render without this.  wtf?
 206
 207         return res, err
 208 }
 209
 210 func (c *Client) showErrMsg(msg string) {
 211         t := time.Now().Format(time.RFC850)
 212
 213         title := "| Error |"
 214
 215         msgBox := tview.NewTextView().SetScrollable(true)
 216         msgBox.SetText(msg).SetBackgroundColor(tcell.ColorDarkRed)
 217         msgBox.SetTitle(title).SetBorder(true)
 218         msgBox.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
 219                 switch event.Key() {
 220                 case tcell.KeyEscape:
 221                         c.UI.Pages.RemovePage("serverMsgModal" + t)
 222                 }
 223                 return event
 224         })
 225
 226         centeredFlex := tview.NewFlex().
 227                 AddItem(nil, 0, 1, false).
 228                 AddItem(tview.NewFlex().SetDirection(tview.FlexRow).
 229                         AddItem(nil, 0, 1, false).
 230                         AddItem(msgBox, 0, 2, true).
 231                         AddItem(nil, 0, 1, false), 0, 2, true).
 232                 AddItem(nil, 0, 1, false)
 233
 234         c.UI.Pages.AddPage("serverMsgModal"+t, centeredFlex, true, true)
 235         c.UI.App.Draw() // TODO: errModal doesn't render without this.  wtf?
 236 }
 237
 238 func handleGetFileNameList(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 239         if t.IsError() {
 240                 c.showErrMsg(string(t.GetField(FieldError).Data))
 241                 return res, err
 242         }
 243
 244         fTree := tview.NewTreeView().SetTopLevel(1)
 245         root := tview.NewTreeNode("Root")
 246         fTree.SetRoot(root).SetCurrentNode(root)
 247         fTree.SetBorder(true).SetTitle("| Files |")
 248         fTree.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
 249                 switch event.Key() {
 250                 case tcell.KeyEscape:
 251                         c.UI.Pages.RemovePage("files")
 252                         c.filePath = []string{}
 253                 case tcell.KeyEnter:
 254                         selectedNode := fTree.GetCurrentNode()
 255
 256                         if selectedNode.GetText() == "<- Back" {
 257                                 c.filePath = c.filePath[:len(c.filePath)-1]
 258                                 f := NewField(FieldFilePath, EncodeFilePath(strings.Join(c.filePath, "/")))
 259
 260                                 if err := c.UI.HLClient.Send(*NewTransaction(TranGetFileNameList, nil, f)); err != nil {
 261                                         c.UI.HLClient.Logger.Error("err", "err", err)
 262                                 }
 263                                 return event
 264                         }
 265
 266                         entry := selectedNode.GetReference().(*FileNameWithInfo)
 267
 268                         if bytes.Equal(entry.Type[:], []byte("fldr")) {
 269                                 c.Logger.Info("get new directory listing", "name", string(entry.name))
 270
 271                                 c.filePath = append(c.filePath, string(entry.name))
 272                                 f := NewField(FieldFilePath, EncodeFilePath(strings.Join(c.filePath, "/")))
 273
 274                                 if err := c.UI.HLClient.Send(*NewTransaction(TranGetFileNameList, nil, f)); err != nil {
 275                                         c.UI.HLClient.Logger.Error("err", "err", err)
 276                                 }
 277                         } else {
 278                                 // TODO: initiate file download
 279                                 c.Logger.Info("download file", "name", string(entry.name))
 280                         }
 281                 }
 282
 283                 return event
 284         })
 285
 286         if len(c.filePath) > 0 {
 287                 node := tview.NewTreeNode("<- Back")
 288                 root.AddChild(node)
 289         }
 290
 291         for _, f := range t.Fields {
 292                 var fn FileNameWithInfo
 293                 err = fn.UnmarshalBinary(f.Data)
 294                 if err != nil {
 295                         return nil, nil
 296                 }
 297
 298                 if bytes.Equal(fn.Type[:], []byte("fldr")) {
 299                         node := tview.NewTreeNode(fmt.Sprintf("[blue::]📁 %s[-:-:-]", fn.name))
 300                         node.SetReference(&fn)
 301                         root.AddChild(node)
 302                 } else {
 303                         size := binary.BigEndian.Uint32(fn.FileSize[:]) / 1024
 304
 305                         node := tview.NewTreeNode(fmt.Sprintf("   %-40s %10v KB", fn.name, size))
 306                         node.SetReference(&fn)
 307                         root.AddChild(node)
 308                 }
 309         }
 310
 311         centerFlex := tview.NewFlex().
 312                 AddItem(nil, 0, 1, false).
 313                 AddItem(tview.NewFlex().
 314                         SetDirection(tview.FlexRow).
 315                         AddItem(nil, 0, 1, false).
 316                         AddItem(fTree, 20, 1, true).
 317                         AddItem(nil, 0, 1, false), 60, 1, true).
 318                 AddItem(nil, 0, 1, false)
 319
 320         c.UI.Pages.AddPage("files", centerFlex, true, true)
 321         c.UI.App.Draw()
 322
 323         return res, err
 324 }
 325
 326 func handleGetMsgs(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 327         newsText := string(t.GetField(FieldData).Data)
 328         newsText = strings.ReplaceAll(newsText, "\r", "\n")
 329
 330         newsTextView := tview.NewTextView().
 331                 SetText(newsText).
 332                 SetDoneFunc(func(key tcell.Key) {
 333                         c.UI.Pages.SwitchToPage(serverUIPage)
 334                         c.UI.App.SetFocus(c.UI.chatInput)
 335                 })
 336         newsTextView.SetBorder(true).SetTitle("News")
 337
 338         c.UI.Pages.AddPage("news", newsTextView, true, true)
 339         // c.UI.Pages.SwitchToPage("news")
 340         // c.UI.App.SetFocus(newsTextView)
 341         c.UI.App.Draw()
 342
 343         return res, err
 344 }
 345
 346 func handleNotifyChangeUser(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 347         newUser := User{
 348                 ID:    t.GetField(FieldUserID).Data,
 349                 Name:  string(t.GetField(FieldUserName).Data),
 350                 Icon:  t.GetField(FieldUserIconID).Data,
 351                 Flags: t.GetField(FieldUserFlags).Data,
 352         }
 353
 354         // Possible cases:
 355         // user is new to the server
 356         // user is already on the server but has a new name
 357
 358         var oldName string
 359         var newUserList []User
 360         updatedUser := false
 361         for _, u := range c.UserList {
 362                 if bytes.Equal(newUser.ID, u.ID) {
 363                         oldName = u.Name
 364                         u.Name = newUser.Name
 365                         if u.Name != newUser.Name {
 366                                 _, _ = fmt.Fprintf(c.UI.chatBox, " <<< "+oldName+" is now known as "+newUser.Name+" >>>\n")
 367                         }
 368                         updatedUser = true
 369                 }
 370                 newUserList = append(newUserList, u)
 371         }
 372
 373         if !updatedUser {
 374                 newUserList = append(newUserList, newUser)
 375         }
 376
 377         c.UserList = newUserList
 378
 379         c.renderUserList()
 380
 381         return res, err
 382 }
 383
 384 func handleNotifyDeleteUser(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 385         exitUser := t.GetField(FieldUserID).Data
 386
 387         var newUserList []User
 388         for _, u := range c.UserList {
 389                 if !bytes.Equal(exitUser, u.ID) {
 390                         newUserList = append(newUserList, u)
 391                 }
 392         }
 393
 394         c.UserList = newUserList
 395
 396         c.renderUserList()
 397
 398         return res, err
 399 }
 400
 401 func handleClientGetUserNameList(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 402         var users []User
 403         for _, field := range t.Fields {
 404                 // The Hotline protocol docs say that ClientGetUserNameList should only return FieldUsernameWithInfo (300)
 405                 // fields, but shxd sneaks in FieldChatSubject (115) so it's important to filter explicitly for the expected
 406                 // field type.  Probably a good idea to do everywhere.
 407                 if bytes.Equal(field.ID, []byte{0x01, 0x2c}) {
 408                         u, err := ReadUser(field.Data)
 409                         if err != nil {
 410                                 return res, err
 411                         }
 412                         users = append(users, *u)
 413                 }
 414         }
 415         c.UserList = users
 416
 417         c.renderUserList()
 418
 419         return res, err
 420 }
 421
 422 func (c *Client) renderUserList() {
 423         c.UI.userList.Clear()
 424         for _, u := range c.UserList {
 425                 flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(u.Flags)))
 426                 if flagBitmap.Bit(UserFlagAdmin) == 1 {
 427                         _, _ = fmt.Fprintf(c.UI.userList, "[red::b]%s[-:-:-]\n", u.Name)
 428                 } else {
 429                         _, _ = fmt.Fprintf(c.UI.userList, "%s\n", u.Name)
 430                 }
 431                 // TODO: fade if user is away
 432         }
 433 }
 434
 435 func handleClientChatMsg(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 436         if c.Pref.EnableBell {
 437                 fmt.Println("\a")
 438         }
 439
 440         _, _ = fmt.Fprintf(c.UI.chatBox, "%s \n", t.GetField(FieldData).Data)
 441
 442         return res, err
 443 }
 444
 445 func handleClientTranUserAccess(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 446         c.UserAccess = t.GetField(FieldUserAccess).Data
 447
 448         return res, err
 449 }
 450
 451 func handleClientTranShowAgreement(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 452         agreement := string(t.GetField(FieldData).Data)
 453         agreement = strings.ReplaceAll(agreement, "\r", "\n")
 454
 455         agreeModal := tview.NewModal().
 456                 SetText(agreement).
 457                 AddButtons([]string{"Agree", "Disagree"}).
 458                 SetDoneFunc(func(buttonIndex int, buttonLabel string) {
 459                         if buttonIndex == 0 {
 460                                 res = append(res,
 461                                         *NewTransaction(
 462                                                 TranAgreed, nil,
 463                                                 NewField(FieldUserName, []byte(c.Pref.Username)),
 464                                                 NewField(FieldUserIconID, c.Pref.IconBytes()),
 465                                                 NewField(FieldUserFlags, []byte{0x00, 0x00}),
 466                                                 NewField(FieldOptions, []byte{0x00, 0x00}),
 467                                         ),
 468                                 )
 469                                 c.UI.Pages.HidePage("agreement")
 470                                 c.UI.App.SetFocus(c.UI.chatInput)
 471                         } else {
 472                                 _ = c.Disconnect()
 473                                 c.UI.Pages.SwitchToPage("home")
 474                         }
 475                 },
 476                 )
 477
 478         c.UI.Pages.AddPage("agreement", agreeModal, false, true)
 479
 480         return res, err
 481 }
 482
 483 func handleClientTranLogin(ctx context.Context, c *Client, t *Transaction) (res []Transaction, err error) {
 484         if !bytes.Equal(t.ErrorCode, []byte{0, 0, 0, 0}) {
 485                 errMsg := string(t.GetField(FieldError).Data)
 486                 errModal := tview.NewModal()
 487                 errModal.SetText(errMsg)
 488                 errModal.AddButtons([]string{"Oh no"})
 489                 errModal.SetDoneFunc(func(buttonIndex int, buttonLabel string) {
 490                         c.UI.Pages.RemovePage("errModal")
 491                 })
 492                 c.UI.Pages.RemovePage("joinServer")
 493                 c.UI.Pages.AddPage("errModal", errModal, false, true)
 494
 495                 c.UI.App.Draw() // TODO: errModal doesn't render without this.  wtf?
 496
 497                 c.Logger.Error(string(t.GetField(FieldError).Data))
 498                 return nil, errors.New("login error: " + string(t.GetField(FieldError).Data))
 499         }
 500         c.UI.Pages.AddAndSwitchToPage(serverUIPage, c.UI.renderServerUI(), true)
 501         c.UI.App.SetFocus(c.UI.chatInput)
 502
 503         if err := c.Send(*NewTransaction(TranGetUserNameList, nil)); err != nil {
 504                 c.Logger.Error("err", "err", err)
 505         }
 506         return res, err
 507 }
 508
 509 // JoinServer connects to a Hotline server and completes the login flow
 510 func (c *Client) Connect(address, login, passwd string) (err error) {
 511         // Establish TCP connection to server
 512         c.Connection, err = net.DialTimeout("tcp", address, 5*time.Second)
 513         if err != nil {
 514                 return err
 515         }
 516
 517         // Send handshake sequence
 518         if err := c.Handshake(); err != nil {
 519                 return err
 520         }
 521
 522         // Authenticate (send TranLogin 107)
 523         if err := c.LogIn(login, passwd); err != nil {
 524                 return err
 525         }
 526
 527         // start keepalive go routine
 528         go func() { _ = c.keepalive() }()
 529
 530         return nil
 531 }
 532
 533 const keepaliveInterval = 300 * time.Second
 534
 535 func (c *Client) keepalive() error {
 536         for {
 537                 time.Sleep(keepaliveInterval)
 538                 _ = c.Send(*NewTransaction(TranKeepAlive, nil))
 539         }
 540 }
 541
 542 var ClientHandshake = []byte{
 543         0x54, 0x52, 0x54, 0x50, // TRTP
 544         0x48, 0x4f, 0x54, 0x4c, // HOTL
 545         0x00, 0x01,
 546         0x00, 0x02,
 547 }
 548
 549 var ServerHandshake = []byte{
 550         0x54, 0x52, 0x54, 0x50, // TRTP
 551         0x00, 0x00, 0x00, 0x00, // ErrorCode
 552 }
 553
 554 func (c *Client) Handshake() error {
 555         // Protocol ID  4       ‘TRTP’      0x54 52 54 50
 556         // Sub-protocol ID      4               User defined
 557         // Version      2       1       Currently 1
 558         // Sub-version  2               User defined
 559         if _, err := c.Connection.Write(ClientHandshake); err != nil {
 560                 return fmt.Errorf("handshake write err: %s", err)
 561         }
 562
 563         replyBuf := make([]byte, 8)
 564         _, err := c.Connection.Read(replyBuf)
 565         if err != nil {
 566                 return err
 567         }
 568
 569         if bytes.Equal(replyBuf, ServerHandshake) {
 570                 return nil
 571         }
 572
 573         // In the case of an error, client and server close the connection.
 574         return fmt.Errorf("handshake response err: %s", err)
 575 }
 576
 577 func (c *Client) LogIn(login string, password string) error {
 578         return c.Send(
 579                 *NewTransaction(
 580                         TranLogin, nil,
 581                         NewField(FieldUserName, []byte(c.Pref.Username)),
 582                         NewField(FieldUserIconID, c.Pref.IconBytes()),
 583                         NewField(FieldUserLogin, negateString([]byte(login))),
 584                         NewField(FieldUserPassword, negateString([]byte(password))),
 585                 ),
 586         )
 587 }
 588
 589 func (c *Client) Send(t Transaction) error {
 590         requestNum := binary.BigEndian.Uint16(t.Type)
 591
 592         // if transaction is NOT reply, add it to the list to transactions we're expecting a response for
 593         if t.IsReply == 0 {
 594                 c.activeTasks[binary.BigEndian.Uint32(t.ID)] = &t
 595         }
 596
 597         b, err := t.MarshalBinary()
 598         if err != nil {
 599                 return err
 600         }
 601
 602         var n int
 603         if n, err = c.Connection.Write(b); err != nil {
 604                 return err
 605         }
 606         c.Logger.Debug("Sent Transaction",
 607                 "IsReply", t.IsReply,
 608                 "type", requestNum,
 609                 "sentBytes", n,
 610         )
 611         return nil
 612 }
 613
 614 func (c *Client) HandleTransaction(ctx context.Context, t *Transaction) error {
 615         var origT Transaction
 616         if t.IsReply == 1 {
 617                 requestID := binary.BigEndian.Uint32(t.ID)
 618                 origT = *c.activeTasks[requestID]
 619                 t.Type = origT.Type
 620         }
 621
 622         if handler, ok := c.Handlers[binary.BigEndian.Uint16(t.Type)]; ok {
 623                 c.Logger.Debug(
 624                         "Received transaction",
 625                         "IsReply", t.IsReply,
 626                         "type", binary.BigEndian.Uint16(t.Type),
 627                 )
 628                 outT, _ := handler(ctx, c, t)
 629                 for _, t := range outT {
 630                         if err := c.Send(t); err != nil {
 631                                 return err
 632                         }
 633                 }
 634         } else {
 635                 c.Logger.Debug(
 636                         "Unimplemented transaction type",
 637                         "IsReply", t.IsReply,
 638                         "type", binary.BigEndian.Uint16(t.Type),
 639                 )
 640         }
 641
 642         return nil
 643 }
 644
 645 func (c *Client) Disconnect() error {
 646         return c.Connection.Close()
 647 }
 648
 649
 650 func (c *Client) HandleTransactions(ctx context.Context) error {
 651         // Create a new scanner for parsing incoming bytes into transaction tokens
 652         scanner := bufio.NewScanner(c.Connection)
 653         scanner.Split(transactionScanner)
 654
 655         // Scan for new transactions and handle them as they come in.
 656         for scanner.Scan() {
 657                 // Make a new []byte slice and copy the scanner bytes to it.  This is critical to avoid a data race as the
 658                 // scanner re-uses the buffer for subsequent scans.
 659                 buf := make([]byte, len(scanner.Bytes()))
 660                 copy(buf, scanner.Bytes())
 661
 662                 var t Transaction
 663                 _, err := t.Write(buf)
 664                 if err != nil {
 665                         break
 666                 }
 667
 668                 if err := c.HandleTransaction(ctx, &t); err != nil {
 669                         c.Logger.Error("Error handling transaction", "err", err)
 670                 }
 671         }
 672
 673         if scanner.Err() == nil {
 674                 return scanner.Err()
 675         }
 676         return nil
 677 }