Make all TCP methods optional; at least FTP data is a read-only

connection and so legitimately ignores acked() and senddata().

src/net/tcp.c

 	assert ( conn->tcp_op->newdata != NULL );
 	assert ( conn->tcp_op->senddata != NULL );
 
-	if ( uip_aborted() && op->aborted ) /* optional method */
+	if ( uip_aborted() && op->aborted )
 		op->aborted ( conn );
-	if ( uip_timedout() && op->timedout ) /* optional method */
+	if ( uip_timedout() && op->timedout )
 		op->timedout ( conn );
-	if ( uip_closed() && op->closed ) /* optional method */
+	if ( uip_closed() && op->closed )
 		op->closed ( conn );
-	if ( uip_connected() )
+	if ( uip_connected() && op->connected )
 		op->connected ( conn );
-	if ( uip_acked() )
+	if ( uip_acked() && op->acked )
 		op->acked ( conn, uip_conn->len );
-	if ( uip_newdata() )
+	if ( uip_newdata() && op->newdata )
 		op->newdata ( conn, ( void * ) uip_appdata, uip_len );
-	if ( uip_rexmit() || uip_newdata() || uip_acked() ||
-	     uip_connected() || uip_poll() )
+	if ( ( uip_rexmit() || uip_newdata() || uip_acked() ||
+	       uip_connected() || uip_poll() ) && op->senddata )
 		op->senddata ( conn );
 }
 
  * This calls tcp_periodic() at regular intervals.
  */
 static void tcp_step ( struct process *process ) {
-	static long timeout = 0;
+	static unsigned long timeout = 0;
 
 	if ( currticks() > timeout ) {
 		timeout = currticks() + ( TICKS_PER_SEC / 10 );

src/net/tcp/ftp.c

 	ftp_complete ( ftp, 1 );
 }
 
-static void ftp_connected ( struct tcp_connection *conn ) {
-	struct ftp_request *ftp = tcp_to_ftp ( conn );
-
-	/* Nothing to do */
-}
-
 static void ftp_acked ( struct tcp_connection *conn, size_t len ) {
 	struct ftp_request *ftp = tcp_to_ftp ( conn );
 	
 	ftp->already_sent += len;
 }
 
-static int ftp_open_passive ( struct ftp_request *ftp ) {
+int ftp_open_passive ( struct ftp_request *ftp ) {
 	char *ptr = ftp->passive_text;
 	uint8_t *byte = ( uint8_t * ) ( &ftp->tcp_data.sin );
 	int i;
 	return 0;
 }
 
-static void ftp_reply ( struct ftp_request *ftp ) {
+void ftp_reply ( struct ftp_request *ftp ) {
 	char status_major = ftp->status_text[0];
 	int success;
 
 	.aborted	= ftp_aborted,
 	.timedout	= ftp_timedout,
 	.closed		= ftp_closed,
-	.connected	= ftp_connected,
 	.acked		= ftp_acked,
 	.newdata	= ftp_newdata,
 	.senddata	= ftp_senddata,
 	ftp_complete ( ftp, -ETIMEDOUT );
 }
 
-static void ftp_data_closed ( struct tcp_connection *conn ) {
-	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
-
-	/* Nothing to do */
-}
-
-static void ftp_data_connected ( struct tcp_connection *conn ) {
-	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
-
-	/* Nothing to do */
-}
-
-static void ftp_data_acked ( struct tcp_connection *conn, size_t len ) {
-	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
-	
-	/* Nothing to do */
-}
-
 static void ftp_data_newdata ( struct tcp_connection *conn,
 			       void *data, size_t len ) {
 	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
 	ftp->callback ( data, len );
 }
 
-static void ftp_data_senddata ( struct tcp_connection *conn ) {
-	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
-	
-	/* Nothing to do */
-}
-
 static struct tcp_operations ftp_data_tcp_operations = {
 	.aborted	= ftp_data_aborted,
 	.timedout	= ftp_data_timedout,
-	.closed		= ftp_data_closed,
-	.connected	= ftp_data_connected,
-	.acked		= ftp_data_acked,
 	.newdata	= ftp_data_newdata,
-	.senddata	= ftp_data_senddata,
 };
 
 /**