Add ldapserver source in here & add support for client state

1 files changed, 145 insertions, 0 deletions

diff --git a/ldapserver/server.go b/ldapserver/server.go
new file mode 100644
index 0000000..3640d0a
--- /dev/null
+++ b/ldapserver/server.go
@@ -0,0 +1,145 @@
+package ldapserver
+
+import (
+	"bufio"
+	"net"
+	"sync"
+	"time"
+)
+
+// Server is an LDAP server.
+type Server struct {
+	Listener     net.Listener
+	ReadTimeout  time.Duration  // optional read timeout
+	WriteTimeout time.Duration  // optional write timeout
+	wg           sync.WaitGroup // group of goroutines (1 by client)
+	chDone       chan bool      // Channel Done, value => shutdown
+
+	// OnNewConnection, if non-nil, is called on new connections.
+	// If it returns non-nil, the connection is closed.
+	OnNewConnection func(c net.Conn) error
+
+	// Handler handles ldap message received from client
+	// it SHOULD "implement" RequestHandler interface
+	Handler Handler
+	NewUserState func() UserState
+}
+
+//NewServer return a LDAP Server
+func NewServer() *Server {
+	return &Server{
+		chDone: make(chan bool),
+	}
+}
+
+// Handle registers the handler for the server.
+// If a handler already exists for pattern, Handle panics
+func (s *Server) Handle(h Handler) {
+	if s.Handler != nil {
+		panic("LDAP: multiple Handler registrations")
+	}
+	s.Handler = h
+}
+
+// ListenAndServe listens on the TCP network address s.Addr and then
+// calls Serve to handle requests on incoming connections.  If
+// s.Addr is blank, ":389" is used.
+func (s *Server) ListenAndServe(addr string, options ...func(*Server)) error {
+
+	if addr == "" {
+		addr = ":389"
+	}
+
+	var e error
+	s.Listener, e = net.Listen("tcp", addr)
+	if e != nil {
+		return e
+	}
+	Logger.Printf("Listening on %s\n", addr)
+
+	for _, option := range options {
+		option(s)
+	}
+
+	return s.serve()
+}
+
+// Handle requests messages on the ln listener
+func (s *Server) serve() error {
+	defer s.Listener.Close()
+
+	if s.Handler == nil {
+		Logger.Panicln("No LDAP Request Handler defined")
+	}
+
+	i := 0
+
+	for {
+		select {
+		case <-s.chDone:
+			Logger.Print("Stopping server")
+			s.Listener.Close()
+			return nil
+		default:
+		}
+
+		rw, err := s.Listener.Accept()
+
+		if s.ReadTimeout != 0 {
+			rw.SetReadDeadline(time.Now().Add(s.ReadTimeout))
+		}
+		if s.WriteTimeout != 0 {
+			rw.SetWriteDeadline(time.Now().Add(s.WriteTimeout))
+		}
+		if nil != err {
+			if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() {
+				continue
+			}
+			Logger.Println(err)
+		}
+
+		cli, err := s.newClient(rw)
+
+		if err != nil {
+			continue
+		}
+
+		i = i + 1
+		cli.Numero = i
+		Logger.Printf("Connection client [%d] from %s accepted", cli.Numero, cli.rwc.RemoteAddr().String())
+		s.wg.Add(1)
+		go cli.serve()
+	}
+
+	return nil
+}
+
+// Return a new session with the connection
+// client has a writer and reader buffer
+func (s *Server) newClient(rwc net.Conn) (c *client, err error) {
+	c = &client{
+		srv:       s,
+		rwc:       rwc,
+		br:        bufio.NewReader(rwc),
+		bw:        bufio.NewWriter(rwc),
+		userState: s.NewUserState(),
+	}
+	return c, nil
+}
+
+// Termination of the LDAP session is initiated by the server sending a
+// Notice of Disconnection.  In this case, each
+// protocol peer gracefully terminates the LDAP session by ceasing
+// exchanges at the LDAP message layer, tearing down any SASL layer,
+// tearing down any TLS layer, and closing the transport connection.
+// A protocol peer may determine that the continuation of any
+// communication would be pernicious, and in this case, it may abruptly
+// terminate the session by ceasing communication and closing the
+// transport connection.
+// In either case, when the LDAP session is terminated.
+func (s *Server) Stop() {
+	close(s.chDone)
+	Logger.Print("gracefully closing client connections...")
+	s.wg.Wait()
+	Logger.Print("all clients connection closed")
+}