--- a/svr-x11fwd.c	Tue Jan 23 23:27:40 2018 +0800
+++ b/svr-x11fwd.c	Sat Feb 17 19:29:51 2018 +0800
@@ -38,9 +38,9 @@
 #define X11BASEPORT 6000
 #define X11BINDBASE 6010
 
-static void x11accept(struct Listener* listener, int sock);
+static void x11accept(const struct Listener* listener, int sock);
 static int bindport(int fd);
-static int send_msg_channel_open_x11(int fd, struct sockaddr_in* addr);
+static int send_msg_channel_open_x11(int fd, const struct sockaddr_in* addr);
 
 /* Check untrusted xauth strings for metacharacters */
 /* Returns DROPBEAR_SUCCESS/DROPBEAR_FAILURE */
@@ -126,7 +126,7 @@
 
 /* accepts a new X11 socket */
 /* returns DROPBEAR_FAILURE or DROPBEAR_SUCCESS */
-static void x11accept(struct Listener* listener, int sock) {
+static void x11accept(const struct Listener* listener, int sock) {
 
 	int fd;
 	struct sockaddr_in addr;
@@ -154,7 +154,7 @@
 
 /* This is called after switching to the user, and sets up the xauth
  * and environment variables.  */
-void x11setauth(struct ChanSess *chansess) {
+void x11setauth(const struct ChanSess *chansess) {
 
 	char display[20]; /* space for "localhost:12345.123" */
 	FILE * authprog = NULL;
@@ -220,7 +220,7 @@
 };
 
 
-static int send_msg_channel_open_x11(int fd, struct sockaddr_in* addr) {
+static int send_msg_channel_open_x11(int fd, const struct sockaddr_in* addr) {
 
 	char* ipstring = NULL;