package ldapserver import ( "bufio" "net" "sync" "time" ldap "github.com/vjeantet/goldap/message" ) type UserState interface{} type client struct { Numero int srv *Server rwc net.Conn br *bufio.Reader bw *bufio.Writer chanOut chan *ldap.LDAPMessage wg sync.WaitGroup closing chan bool requestList map[int]*Message mutex sync.Mutex writeDone chan bool rawData []byte userState UserState } func (c *client) GetConn() net.Conn { return c.rwc } func (c *client) GetRaw() []byte { return c.rawData } func (c *client) SetConn(conn net.Conn) { c.rwc = conn c.br = bufio.NewReader(c.rwc) c.bw = bufio.NewWriter(c.rwc) } func (c *client) GetMessageByID(messageID int) (*Message, bool) { if requestToAbandon, ok := c.requestList[messageID]; ok { return requestToAbandon, true } return nil, false } func (c *client) Addr() net.Addr { return c.rwc.RemoteAddr() } func (c *client) ReadPacket() (*messagePacket, error) { mP, err := readMessagePacket(c.br) c.rawData = make([]byte, len(mP.bytes)) copy(c.rawData, mP.bytes) return mP, err } func (c *client) serve() { defer c.close() c.closing = make(chan bool) if onc := c.srv.OnNewConnection; onc != nil { if err := onc(c.rwc); err != nil { Logger.Printf("Erreur OnNewConnection: %s", err) return } } // Create the ldap response queue to be writted to client (buffered to 20) // buffered to 20 means that If client is slow to handler responses, Server // Handlers will stop to send more respones c.chanOut = make(chan *ldap.LDAPMessage) c.writeDone = make(chan bool) // for each message in c.chanOut send it to client go func() { for msg := range c.chanOut { c.writeMessage(msg) } close(c.writeDone) }() // Listen for server signal to shutdown go func() { for { select { case <-c.srv.chDone: // server signals shutdown process c.wg.Add(1) r := NewExtendedResponse(LDAPResultUnwillingToPerform) r.SetDiagnosticMessage("server is about to stop") r.SetResponseName(NoticeOfDisconnection) m := ldap.NewLDAPMessageWithProtocolOp(r) c.chanOut <- m c.wg.Done() c.rwc.SetReadDeadline(time.Now().Add(time.Millisecond)) return case <-c.closing: return } } }() c.requestList = make(map[int]*Message) for { if c.srv.ReadTimeout != 0 { c.rwc.SetReadDeadline(time.Now().Add(c.srv.ReadTimeout)) } if c.srv.WriteTimeout != 0 { c.rwc.SetWriteDeadline(time.Now().Add(c.srv.WriteTimeout)) } //Read client input as a ASN1/BER binary message messagePacket, err := c.ReadPacket() if err != nil { if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() { Logger.Printf("Sorry client %d, i can not wait anymore (reading timeout) ! %s", c.Numero, err) } else { Logger.Printf("Error readMessagePacket: %s", err) } return } //Convert ASN1 binaryMessage to a ldap Message message, err := messagePacket.readMessage() if err != nil { Logger.Printf("Error reading Message : %s\n\t%x", err.Error(), messagePacket.bytes) continue } if DEBUG { Logger.Printf("<<< %d - %s - hex=%x", c.Numero, message.ProtocolOpName(), messagePacket) } // TODO: Use a implementation to limit runnuning request by client // solution 1 : when the buffered output channel is full, send a busy // solution 2 : when 10 client requests (goroutines) are running, send a busy message // And when the limit is reached THEN send a BusyLdapMessage // When message is an UnbindRequest, stop serving if _, ok := message.ProtocolOp().(ldap.UnbindRequest); ok { return } // If client requests a startTls, do not handle it in a // goroutine, connection has to remain free until TLS is OK // @see RFC https://tools.ietf.org/html/rfc4511#section-4.14.1 if req, ok := message.ProtocolOp().(ldap.ExtendedRequest); ok { if req.RequestName() == NoticeOfStartTLS { c.wg.Add(1) c.ProcessRequestMessage(&message) continue } } // TODO: go/non go routine choice should be done in the ProcessRequestMessage // not in the client.serve func c.wg.Add(1) go c.ProcessRequestMessage(&message) } } // close closes client, // * stop reading from client // * signals to all currently running request processor to stop // * wait for all request processor to end // * close client connection // * signal to server that client shutdown is ok func (c *client) close() { if DEBUG { Logger.Printf("client %d close()", c.Numero) } close(c.closing) // stop reading from client c.rwc.SetReadDeadline(time.Now().Add(time.Millisecond)) if DEBUG { Logger.Printf("client %d close() - stop reading from client", c.Numero) } // signals to all currently running request processor to stop c.mutex.Lock() for messageID, request := range c.requestList { Logger.Printf("Client %d close() - sent abandon signal to request[messageID = %d]", c.Numero, messageID) go request.Abandon() } c.mutex.Unlock() if DEBUG { Logger.Printf("client %d close() - Abandon signal sent to processors", c.Numero) } c.wg.Wait() // wait for all current running request processor to end close(c.chanOut) // No more message will be sent to client, close chanOUT if DEBUG { Logger.Printf("client [%d] request processors ended", c.Numero) } <-c.writeDone // Wait for the last message sent to be written c.rwc.Close() // close client connection Logger.Printf("client [%d] connection closed", c.Numero) c.srv.wg.Done() // signal to server that client shutdown is ok } func (c *client) writeMessage(m *ldap.LDAPMessage) { data, _ := m.Write() if DEBUG { Logger.Printf(">>> %d - %s - hex=%x", c.Numero, m.ProtocolOpName(), data.Bytes()) } c.bw.Write(data.Bytes()) c.bw.Flush() } // ResponseWriter interface is used by an LDAP handler to // construct an LDAP response. type ResponseWriter interface { // Write writes the LDAPResponse to the connection as part of an LDAP reply. Write(po ldap.ProtocolOp) } type responseWriterImpl struct { chanOut chan *ldap.LDAPMessage messageID int } func (w responseWriterImpl) Write(po ldap.ProtocolOp) { m := ldap.NewLDAPMessageWithProtocolOp(po) m.SetMessageID(w.messageID) w.chanOut <- m } func (c *client) ProcessRequestMessage(message *ldap.LDAPMessage) { defer c.wg.Done() var m Message m = Message{ LDAPMessage: message, Done: make(chan bool, 2), Client: c, } c.registerRequest(&m) defer c.unregisterRequest(&m) var w responseWriterImpl w.chanOut = c.chanOut w.messageID = m.MessageID().Int() c.srv.Handler.ServeLDAP(c.userState, w, &m) } func (c *client) registerRequest(m *Message) { c.mutex.Lock() c.requestList[m.MessageID().Int()] = m c.mutex.Unlock() } func (c *client) unregisterRequest(m *Message) { c.mutex.Lock() delete(c.requestList, m.MessageID().Int()) c.mutex.Unlock() }