Add an info vnc monitor command

diff -r 64e6128482fb monitor.c
@@ -1297,6 +1297,8 @@ static term_cmd_t info_cmds[] = {
       "", "show the currently saved VM snapshots" },
     { "mice", "", do_info_mice,
       "", "show which guest mouse is receiving events" },
+    { "vnc", "", do_info_vnc,
+      "", "show the vnc server status"},
     { NULL, NULL, },
 };
 

diff -r 64e6128482fb vl.h
@@ -897,6 +897,7 @@ void cocoa_display_init(DisplayState *ds
 
 /* vnc.c */
 void vnc_display_init(DisplayState *ds, const char *display);
+void do_info_vnc(void);
 
 /* ide.c */
 #define MAX_DISKS 4

diff -r 64e6128482fb vnc.c
@@ -73,6 +73,8 @@ struct VncState
     int last_x;
     int last_y;
 
+    const char *display;
+
     Buffer output;
     Buffer input;
     kbd_layout_t *kbd_layout;

@@ -89,6 +91,24 @@ struct VncState
     /* input */
     uint8_t modifiers_state[256];
 };
+
+static VncState *vnc_state; /* needed for info vnc */
+
+void do_info_vnc(void)
+{
+    if (vnc_state == NULL)
+	term_printf("VNC server disabled\n");
+    else {
+	term_printf("VNC server active on: ");
+	term_print_filename(vnc_state->display);
+	term_printf("\n");
+
+	if (vnc_state->csock == -1)
+	    term_printf("No client connected\n");
+	else
+	    term_printf("Client connected\n");
+    }
+}
 
 /* TODO
    1) Get the queue working for IO.

@@ -1150,6 +1170,8 @@ void vnc_display_init(DisplayState *ds, 
 	exit(1);
 
     ds->opaque = vs;
+    vnc_state = vs;
+    vs->display = arg;
 
     vs->lsock = -1;
     vs->csock = -1;