import (
"bufio"
- "bytes"
"context"
"encoding/binary"
"errors"
"net"
"os"
"path/filepath"
- "runtime/debug"
"strings"
"sync"
"time"
name string
}
-const (
- userIdleSeconds = 300 // time in seconds before an inactive user is marked idle
- idleCheckInterval = 10 // time in seconds to check for idle users
- trackerUpdateFrequency = 300 // time in seconds between tracker re-registration
-)
-
-var nostalgiaVersion = []byte{0, 0, 2, 0x2c} // version ID used by the Nostalgia client
-
type Server struct {
- Port int
- Accounts map[string]*Account
- Agreement []byte
- Clients map[uint16]*ClientConn
- ThreadedNews *ThreadedNews
-
+ Port int
+ Accounts map[string]*Account
+ Agreement []byte
+ Clients map[uint16]*ClientConn
fileTransfers map[[4]byte]*FileTransfer
- Config *Config
- ConfigDir string
- Logger *zap.SugaredLogger
- PrivateChats map[uint32]*PrivateChat
+ Config *Config
+ ConfigDir string
+ Logger *zap.SugaredLogger
+
+ PrivateChatsMu sync.Mutex
+ PrivateChats map[uint32]*PrivateChat
+
NextGuestID *uint16
TrackerPassID [4]byte
- Stats *Stats
+
+ StatsMu sync.Mutex
+ Stats *Stats
FS FileStore // Storage backend to use for File storage
outbox chan Transaction
mux sync.Mutex
+ threadedNewsMux sync.Mutex
+ ThreadedNews *ThreadedNews
+
flatNewsMux sync.Mutex
FlatNews []byte
+
+ banListMU sync.Mutex
+ banList map[string]*time.Time
+}
+
+func (s *Server) CurrentStats() Stats {
+ s.StatsMu.Lock()
+ defer s.StatsMu.Unlock()
+
+ stats := s.Stats
+ stats.CurrentlyConnected = len(s.Clients)
+
+ return *stats
}
type PrivateChat struct {
}
func (s *Server) sendTransaction(t Transaction) error {
- requestNum := binary.BigEndian.Uint16(t.Type)
clientID, err := byteToInt(*t.clientID)
if err != nil {
return err
if client == nil {
return fmt.Errorf("invalid client id %v", *t.clientID)
}
- userName := string(client.UserName)
- login := client.Account.Login
-
- handler := TransactionHandlers[requestNum]
b, err := t.MarshalBinary()
if err != nil {
return err
}
- var n int
- if n, err = client.Connection.Write(b); err != nil {
+
+ _, err = client.Connection.Write(b)
+ if err != nil {
return err
}
- s.Logger.Debugw("Sent Transaction",
- "name", userName,
- "login", login,
- "IsReply", t.IsReply,
- "type", handler.Name,
- "sentBytes", n,
- "remoteAddr", client.RemoteAddr,
- )
+
return nil
}
})
go func() {
+ s.Logger.Infow("Connection established", "RemoteAddr", conn.RemoteAddr())
+
+ defer conn.Close()
if err := s.handleNewConnection(connCtx, conn, conn.RemoteAddr().String()); err != nil {
- s.Logger.Infow("New client connection established", "RemoteAddr", conn.RemoteAddr())
if err == io.EOF {
s.Logger.Infow("Client disconnected", "RemoteAddr", conn.RemoteAddr())
} else {
Logger: logger,
NextGuestID: new(uint16),
outbox: make(chan Transaction),
- Stats: &Stats{StartTime: time.Now()},
+ Stats: &Stats{Since: time.Now()},
ThreadedNews: &ThreadedNews{},
FS: FS,
+ banList: make(map[string]*time.Time),
}
var err error
return nil, err
}
+ // try to load the ban list, but ignore errors as this file may not be present or may be empty
+ _ = server.loadBanList(filepath.Join(configDir, "Banlist.yaml"))
+
if err := server.loadThreadedNews(filepath.Join(configDir, "ThreadedNews.yaml")); err != nil {
return nil, err
}
if err := register(t, tr); err != nil {
server.Logger.Errorw("unable to register with tracker %v", "error", err)
}
- server.Logger.Infow("Sent Tracker registration", "data", tr)
+ server.Logger.Debugw("Sent Tracker registration", "addr", t)
}
time.Sleep(trackerUpdateFrequency * time.Second)
if c.IdleTime > userIdleSeconds && !c.Idle {
c.Idle = true
- flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))
+ flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(c.Flags)))
flagBitmap.SetBit(flagBitmap, userFlagAway, 1)
- binary.BigEndian.PutUint16(*c.Flags, uint16(flagBitmap.Int64()))
+ binary.BigEndian.PutUint16(c.Flags, uint16(flagBitmap.Int64()))
c.sendAll(
- tranNotifyChangeUser,
- NewField(fieldUserID, *c.ID),
- NewField(fieldUserFlags, *c.Flags),
- NewField(fieldUserName, c.UserName),
- NewField(fieldUserIconID, *c.Icon),
+ TranNotifyChangeUser,
+ NewField(FieldUserID, *c.ID),
+ NewField(FieldUserFlags, c.Flags),
+ NewField(FieldUserName, c.UserName),
+ NewField(FieldUserIconID, c.Icon),
)
}
}
}
}
+func (s *Server) writeBanList() error {
+ s.banListMU.Lock()
+ defer s.banListMU.Unlock()
+
+ out, err := yaml.Marshal(s.banList)
+ if err != nil {
+ return err
+ }
+ err = ioutil.WriteFile(
+ filepath.Join(s.ConfigDir, "Banlist.yaml"),
+ out,
+ 0666,
+ )
+ return err
+}
+
func (s *Server) writeThreadedNews() error {
- s.mux.Lock()
- defer s.mux.Unlock()
+ s.threadedNewsMux.Lock()
+ defer s.threadedNewsMux.Unlock()
out, err := yaml.Marshal(s.ThreadedNews)
if err != nil {
return err
}
- err = ioutil.WriteFile(
+ err = s.FS.WriteFile(
filepath.Join(s.ConfigDir, "ThreadedNews.yaml"),
out,
0666,
clientConn := &ClientConn{
ID: &[]byte{0, 0},
- Icon: &[]byte{0, 0},
- Flags: &[]byte{0, 0},
+ Icon: []byte{0, 0},
+ Flags: []byte{0, 0},
UserName: []byte{},
Connection: conn,
Server: s,
- Version: &[]byte{},
+ Version: []byte{},
AutoReply: []byte{},
transfers: map[int]map[[4]byte]*FileTransfer{},
- Agreed: false,
RemoteAddr: remoteAddr,
}
clientConn.transfers = map[int]map[[4]byte]*FileTransfer{
}
// NewUser creates a new user account entry in the server map and config file
-func (s *Server) NewUser(login, name, password string, access []byte) error {
+func (s *Server) NewUser(login, name, password string, access accessBitmap) error {
s.mux.Lock()
defer s.mux.Unlock()
Login: login,
Name: name,
Password: hashAndSalt([]byte(password)),
- Access: &access,
+ Access: access,
}
out, err := yaml.Marshal(&account)
if err != nil {
return s.FS.WriteFile(filepath.Join(s.ConfigDir, "Users", login+".yaml"), out, 0666)
}
-func (s *Server) UpdateUser(login, newLogin, name, password string, access []byte) error {
+func (s *Server) UpdateUser(login, newLogin, name, password string, access accessBitmap) error {
s.mux.Lock()
defer s.mux.Unlock()
}
account := s.Accounts[newLogin]
- account.Access = &access
+ account.Access = access
account.Name = name
account.Password = password
var connectedUsers []Field
for _, c := range sortedClients(s.Clients) {
- if !c.Agreed {
- continue
- }
user := User{
ID: *c.ID,
- Icon: *c.Icon,
- Flags: *c.Flags,
+ Icon: c.Icon,
+ Flags: c.Flags,
Name: string(c.UserName),
}
- connectedUsers = append(connectedUsers, NewField(fieldUsernameWithInfo, user.Payload()))
+ connectedUsers = append(connectedUsers, NewField(FieldUsernameWithInfo, user.Payload()))
}
return connectedUsers
}
+func (s *Server) loadBanList(path string) error {
+ fh, err := os.Open(path)
+ if err != nil {
+ return err
+ }
+ decoder := yaml.NewDecoder(fh)
+
+ return decoder.Decode(s.banList)
+}
+
// loadThreadedNews loads the threaded news data from disk
func (s *Server) loadThreadedNews(threadedNewsPath string) error {
fh, err := os.Open(threadedNewsPath)
return nil
}
-const (
- minTransactionLen = 22 // minimum length of any transaction
-)
-
-// dontPanic recovers and logs panics instead of crashing
-// TODO: remove this after known issues are fixed
-func dontPanic(logger *zap.SugaredLogger) {
- if r := recover(); r != nil {
- fmt.Println("stacktrace from panic: \n" + string(debug.Stack()))
- logger.Errorw("PANIC", "err", r, "trace", string(debug.Stack()))
- }
-}
-
// handleNewConnection takes a new net.Conn and performs the initial login sequence
-func (s *Server) handleNewConnection(ctx context.Context, conn io.ReadWriteCloser, remoteAddr string) error {
+func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser, remoteAddr string) error {
defer dontPanic(s.Logger)
- if err := Handshake(conn); err != nil {
+ if err := Handshake(rwc); err != nil {
return err
}
- buf := make([]byte, 1024)
- // TODO: fix potential short read with io.ReadFull
- readLen, err := conn.Read(buf)
- if readLen < minTransactionLen {
- return err
- }
- if err != nil {
+ // Create a new scanner for parsing incoming bytes into transaction tokens
+ scanner := bufio.NewScanner(rwc)
+ scanner.Split(transactionScanner)
+
+ scanner.Scan()
+
+ // Make a new []byte slice and copy the scanner bytes to it. This is critical to avoid a data race as the
+ // scanner re-uses the buffer for subsequent scans.
+ buf := make([]byte, len(scanner.Bytes()))
+ copy(buf, scanner.Bytes())
+
+ var clientLogin Transaction
+ if _, err := clientLogin.Write(buf); err != nil {
return err
}
- clientLogin, _, err := ReadTransaction(buf[:readLen])
- if err != nil {
- return err
+ // check if remoteAddr is present in the ban list
+ if banUntil, ok := s.banList[strings.Split(remoteAddr, ":")[0]]; ok {
+ // permaban
+ if banUntil == nil {
+ t := NewTransaction(
+ TranServerMsg,
+ &[]byte{0, 0},
+ NewField(FieldData, []byte("You are permanently banned on this server")),
+ NewField(FieldChatOptions, []byte{0, 0}),
+ )
+
+ b, err := t.MarshalBinary()
+ if err != nil {
+ return err
+ }
+
+ _, err = rwc.Write(b)
+ if err != nil {
+ return err
+ }
+
+ time.Sleep(1 * time.Second)
+ return nil
+ }
+
+ // temporary ban
+ if time.Now().Before(*banUntil) {
+ t := NewTransaction(
+ TranServerMsg,
+ &[]byte{0, 0},
+ NewField(FieldData, []byte("You are temporarily banned on this server")),
+ NewField(FieldChatOptions, []byte{0, 0}),
+ )
+ b, err := t.MarshalBinary()
+ if err != nil {
+ return err
+ }
+
+ _, err = rwc.Write(b)
+ if err != nil {
+ return err
+ }
+
+ time.Sleep(1 * time.Second)
+ return nil
+ }
}
- c := s.NewClientConn(conn, remoteAddr)
+ c := s.NewClientConn(rwc, remoteAddr)
defer c.Disconnect()
- encodedLogin := clientLogin.GetField(fieldUserLogin).Data
- encodedPassword := clientLogin.GetField(fieldUserPassword).Data
- *c.Version = clientLogin.GetField(fieldVersion).Data
+ encodedLogin := clientLogin.GetField(FieldUserLogin).Data
+ encodedPassword := clientLogin.GetField(FieldUserPassword).Data
+ c.Version = clientLogin.GetField(FieldVersion).Data
var login string
for _, char := range encodedLogin {
login = GuestAccount
}
+ c.logger = s.Logger.With("remoteAddr", remoteAddr, "login", login)
+
// If authentication fails, send error reply and close connection
if !c.Authenticate(login, encodedPassword) {
- t := c.NewErrReply(clientLogin, "Incorrect login.")
+ t := c.NewErrReply(&clientLogin, "Incorrect login.")
b, err := t.MarshalBinary()
if err != nil {
return err
}
- if _, err := conn.Write(b); err != nil {
+ if _, err := rwc.Write(b); err != nil {
return err
}
- return fmt.Errorf("incorrect login")
- }
- if clientLogin.GetField(fieldUserName).Data != nil {
- c.UserName = clientLogin.GetField(fieldUserName).Data
+ c.logger.Infow("Login failed", "clientVersion", fmt.Sprintf("%x", c.Version))
+
+ return nil
}
- if clientLogin.GetField(fieldUserIconID).Data != nil {
- *c.Icon = clientLogin.GetField(fieldUserIconID).Data
+ if clientLogin.GetField(FieldUserIconID).Data != nil {
+ c.Icon = clientLogin.GetField(FieldUserIconID).Data
}
c.Account = c.Server.Accounts[login]
- if c.Authorize(accessDisconUser) {
- *c.Flags = []byte{0, 2}
+ if clientLogin.GetField(FieldUserName).Data != nil {
+ if c.Authorize(accessAnyName) {
+ c.UserName = clientLogin.GetField(FieldUserName).Data
+ } else {
+ c.UserName = []byte(c.Account.Name)
+ }
}
- c.logger = s.Logger.With("remoteAddr", remoteAddr, "login", login)
-
- c.logger.Infow("Client connection received", "version", fmt.Sprintf("%x", *c.Version))
+ if c.Authorize(accessDisconUser) {
+ c.Flags = []byte{0, 2}
+ }
- s.outbox <- c.NewReply(clientLogin,
- NewField(fieldVersion, []byte{0x00, 0xbe}),
- NewField(fieldCommunityBannerID, []byte{0, 0}),
- NewField(fieldServerName, []byte(s.Config.Name)),
+ s.outbox <- c.NewReply(&clientLogin,
+ NewField(FieldVersion, []byte{0x00, 0xbe}),
+ NewField(FieldCommunityBannerID, []byte{0, 0}),
+ NewField(FieldServerName, []byte(s.Config.Name)),
)
// Send user access privs so client UI knows how to behave
- c.Server.outbox <- *NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, *c.Account.Access))
-
- // Show agreement to client
- c.Server.outbox <- *NewTransaction(tranShowAgreement, c.ID, NewField(fieldData, s.Agreement))
+ c.Server.outbox <- *NewTransaction(TranUserAccess, c.ID, NewField(FieldUserAccess, c.Account.Access[:]))
+
+ // Accounts with accessNoAgreement do not receive the server agreement on login. The behavior is different between
+ // client versions. For 1.2.3 client, we do not send TranShowAgreement. For other client versions, we send
+ // TranShowAgreement but with the NoServerAgreement field set to 1.
+ if c.Authorize(accessNoAgreement) {
+ // If client version is nil, then the client uses the 1.2.3 login behavior
+ if c.Version != nil {
+ c.Server.outbox <- *NewTransaction(TranShowAgreement, c.ID, NewField(FieldNoServerAgreement, []byte{1}))
+ }
+ } else {
+ c.Server.outbox <- *NewTransaction(TranShowAgreement, c.ID, NewField(FieldData, s.Agreement))
+ }
- // Used simplified hotline v1.2.3 login flow for clients that do not send login info in tranAgreed
- if *c.Version == nil || bytes.Equal(*c.Version, nostalgiaVersion) {
- c.Agreed = true
+ // If the client has provided a username as part of the login, we can infer that it is using the 1.2.3 login
+ // flow and not the 1.5+ flow.
+ if len(c.UserName) != 0 {
+ // Add the client username to the logger. For 1.5+ clients, we don't have this information yet as it comes as
+ // part of TranAgreed
c.logger = c.logger.With("name", string(c.UserName))
+ c.logger.Infow("Login successful", "clientVersion", "Not sent (probably 1.2.3)")
+
+ // Notify other clients on the server that the new user has logged in. For 1.5+ clients we don't have this
+ // information yet, so we do it in TranAgreed instead
for _, t := range c.notifyOthers(
*NewTransaction(
- tranNotifyChangeUser, nil,
- NewField(fieldUserName, c.UserName),
- NewField(fieldUserID, *c.ID),
- NewField(fieldUserIconID, *c.Icon),
- NewField(fieldUserFlags, *c.Flags),
+ TranNotifyChangeUser, nil,
+ NewField(FieldUserName, c.UserName),
+ NewField(FieldUserID, *c.ID),
+ NewField(FieldUserIconID, c.Icon),
+ NewField(FieldUserFlags, c.Flags),
),
) {
c.Server.outbox <- t
}
}
- c.Server.Stats.LoginCount += 1
+ c.Server.Stats.ConnectionCounter += 1
+ if len(s.Clients) > c.Server.Stats.ConnectionPeak {
+ c.Server.Stats.ConnectionPeak = len(s.Clients)
+ }
- const readBuffSize = 1024000 // 1KB - TODO: what should this be?
- tranBuff := make([]byte, 0)
- tReadlen := 0
- // Infinite loop where take action on incoming client requests until the connection is closed
- for {
- buf = make([]byte, readBuffSize)
- tranBuff = tranBuff[tReadlen:]
+ // Scan for new transactions and handle them as they come in.
+ for scanner.Scan() {
+ // Make a new []byte slice and copy the scanner bytes to it. This is critical to avoid a data race as the
+ // scanner re-uses the buffer for subsequent scans.
+ buf := make([]byte, len(scanner.Bytes()))
+ copy(buf, scanner.Bytes())
- readLen, err := c.Connection.Read(buf)
- if err != nil {
+ var t Transaction
+ if _, err := t.Write(buf); err != nil {
return err
}
- tranBuff = append(tranBuff, buf[:readLen]...)
- // We may have read multiple requests worth of bytes from Connection.Read. readTransactions splits them
- // into a slice of transactions
- var transactions []Transaction
- if transactions, tReadlen, err = readTransactions(tranBuff); err != nil {
+ if err := c.handleTransaction(t); err != nil {
c.logger.Errorw("Error handling transaction", "err", err)
}
-
- // iterate over all the transactions that were parsed from the byte slice and handle them
- for _, t := range transactions {
- if err := c.handleTransaction(&t); err != nil {
- c.logger.Errorw("Error handling transaction", "err", err)
- }
- }
}
+ return nil
}
func (s *Server) NewPrivateChat(cc *ClientConn) []byte {
- s.mux.Lock()
- defer s.mux.Unlock()
+ s.PrivateChatsMu.Lock()
+ defer s.PrivateChatsMu.Unlock()
randID := make([]byte, 4)
rand.Read(randID)
data := binary.BigEndian.Uint32(randID[:])
s.PrivateChats[data] = &PrivateChat{
- Subject: "",
ClientConn: make(map[uint16]*ClientConn),
}
s.PrivateChats[data].ClientConn[cc.uint16ID()] = cc
delete(s.fileTransfers, t.ReferenceNumber)
s.mux.Unlock()
+ // Wait a few seconds before closing the connection: this is a workaround for problems
+ // observed with Windows clients where the client must initiate close of the TCP connection before
+ // the server does. This is gross and seems unnecessary. TODO: Revisit?
+ time.Sleep(3 * time.Second)
}()
s.mux.Lock()
switch fileTransfer.Type {
case bannerDownload:
if err := s.bannerDownload(rwc); err != nil {
- panic(err)
return err
}
case FileDownload:
s.Stats.DownloadCounter += 1
+ s.Stats.DownloadsInProgress += 1
+ defer func() {
+ s.Stats.DownloadsInProgress -= 1
+ }()
var dataOffset int64
if fileTransfer.fileResumeData != nil {
case FileUpload:
s.Stats.UploadCounter += 1
+ s.Stats.UploadsInProgress += 1
+ defer func() { s.Stats.UploadsInProgress -= 1 }()
var file *os.File
}
rLogger.Infow("File upload complete", "dstFile", fullPath)
+
case FolderDownload:
+ s.Stats.DownloadCounter += 1
+ s.Stats.DownloadsInProgress += 1
+ defer func() { s.Stats.DownloadsInProgress -= 1 }()
+
// Folder Download flow:
// 1. Get filePath from the transfer
// 2. Iterate over files
}
case FolderUpload:
+ s.Stats.UploadCounter += 1
+ s.Stats.UploadsInProgress += 1
+ defer func() { s.Stats.UploadsInProgress -= 1 }()
rLogger.Infow(
"Folder upload started",
"dstPath", fullPath,
git.r.bdr.sh / rbdr / mobius / blobdiff