github/xrdp
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add support for forwarded resize request to VNC module

Browse Source 
This feature was added to the RFB community wiki on 2020-12-22. See
commit a6dab64825b2ce4e9b47b8c9541619b94b7d908b in the rfbproto
repository
This commit is contained in:
matt335672
2025-08-21 12:28:10 +01:00
parent 3700867e87
commit 0ff175c85e
4 changed files with 185 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files
vnc/rfb.c
+1
View File
@@ -31,6 +31,7 @@ static const char *eds_status_msg[] =
/* 1 */ "Resize is administratively prohibited",
/* 2 */ "Out of resources",
/* 3 */ "Invalid screen layout",
/* 4 */ "Request forwarded",
/* others */ "Unknown code"
};
vnc/rfb.h
+12
View File
@@ -80,6 +80,18 @@ enum sec_type
#define RFBPROTO_VER_3_7 MAKE_RFBPROTO_VER(3,7)
#define RFBPROTO_VER_3_8 MAKE_RFBPROTO_VER(3,8)
/*
* ExtendedDesktopSize status codes
*/
enum
{
RFB_EDS_NO_ERROR = 0,
RFB_EDS_ADMINISTRATIVELY_PROHIBITED = 1,
RFB_EDS_OUT_OF_RESOURCES = 2,
RFB_EDS_INVALID_SCREEN_LAYOUT = 3,
RFB_EDS_REQUEST_FORWARDED = 4
};
/**
* Returns an error string for an ExtendedDesktopSize status code
*/
vnc/vnc.c
+165 -31
View File
@@ -38,6 +38,7 @@
#include "vnc_clip.h"
#include "rfb.h"
#include "log.h"
#include "timers.h"
#include "trans.h"
#include "ssl_calls.h"
#include "string_calls.h"
@@ -53,6 +54,12 @@ enum
MSK_EXTENDED_DESKTOP_SIZE = (1 << 0)
};
enum
{
/** Time to wait for a forwarded resize to complete */
FORWARDED_RESIZE_TIMEOUT = 1500 /* milli-seconds */
};
/******************************************************************************/
int
lib_send_copy(struct vnc *v, struct stream *s)
@@ -309,7 +316,8 @@ send_set_desktop_size(struct vnc *v, const struct vnc_screen_layout *layout)
out_uint32_be(s, layout->s[i].flags);
}
s_mark_end(s);
LOG(LOG_LEVEL_DEBUG, "VNC Sending SetDesktopSize");
LOG(LOG_LEVEL_DEBUG, "VNC_RESIZE: Sending SetDesktopSize %dx%d",
layout->total_width, layout->total_height);
error = lib_send_copy(v, s);
free_stream(s);
@@ -954,7 +962,7 @@ skip_encoding(struct vnc *v, int x, int y, int cx, int cy,
{
struct vnc_screen_layout layout = {0};
LOG(LOG_LEVEL_DEBUG,
"Skipping RFB_ENC_EXTENDED_DESKTOP_SIZE encoding "
"VNC_RESIZE: Skipping RFB_ENC_EXTENDED_DESKTOP_SIZE encoding "
"x=%d, y=%d geom=%dx%d",
x, y, cx, cy);
error = read_extended_desktop_size_rect(v, &layout);
@@ -1033,7 +1041,7 @@ find_matching_extended_rect(struct vnc *v,
match(x, y, cx, cy))
{
LOG(LOG_LEVEL_DEBUG,
"VNC matched ExtendedDesktopSize rectangle "
"VNC_RESIZE: VNC matched ExtendedDesktopSize rectangle "
"x=%d, y=%d geom=%dx%d",
x, y, cx, cy);
found = 1;
@@ -1149,6 +1157,18 @@ rect_is_reply_to_us(int x, int y, int cx, int cy)
return (x == 1);
}
/**************************************************************************//**
* Tests if extended desktop size rect is a general change.
*
* This happens when we are looking for a layout change that the
* VNC server has reported as forwarded to the real desktop.
*/
static int
rect_is_general_change(int x, int y, int cx, int cy)
{
return (x == 0);
}
/**************************************************************************//**
* Handles the first framebuffer update from the server
*
@@ -1249,47 +1269,138 @@ lib_framebuffer_waiting_for_resize_confirm(struct vnc *v)
{
if (layout.count > 0)
{
if (response_code == 0)
if (response_code == RFB_EDS_REQUEST_FORWARDED)
{
LOG(LOG_LEVEL_DEBUG, "VNC server successfully resized");
log_screen_layout(LOG_LEVEL_INFO, "NewLayout", &layout);
v->server_layout = layout;
LOG(LOG_LEVEL_DEBUG, "VNC_RESIZE: VNC server resize forwarded");
log_screen_layout(LOG_LEVEL_INFO, "ForwardedLayout", &layout);
v->forward_timer =
timers_oneshot_init(FORWARDED_RESIZE_TIMEOUT);
v->forwarded_layout = layout;
}
else
{
LOG(LOG_LEVEL_WARNING,
"VNC server resize failed - error code %d [%s]",
response_code,
rfb_get_eds_status_msg(response_code));
// This is awkward. The client has asked for a specific size
// which we can't support.
//
// Currently we handle this by queueing a resize to our
// supported size, and continuing with the resize state
// machine in xrdp_mm.c
LOG(LOG_LEVEL_WARNING, "Resizing client to server");
error = resize_client_to_server(v, 0);
}
// The resize has either succeeded or failed
if (response_code == RFB_EDS_NO_ERROR)
{
LOG(LOG_LEVEL_DEBUG, "VNC_RESIZE:"
" VNC server successfully resized");
log_screen_layout(LOG_LEVEL_INFO, "NewLayout", &layout);
v->server_layout = layout;
}
else
{
LOG(LOG_LEVEL_WARNING,
"VNC server resize failed - error code %d [%s]",
response_code,
rfb_get_eds_status_msg(response_code));
// This is awkward. The client has asked for a
// specific size which we can't support.
//
// Currently we handle this by queueing a resize
// to our supported size, and continuing with the
// resize state machine in xrdp_mm.c
LOG(LOG_LEVEL_WARNING, "Resizing client to server");
error = resize_client_to_server(v, 0);
}
if (error == 0)
{
// If this resize was requested by the client mid-session
// (dynamic resize), we need to tell xrdp_mm that
// it's OK to continue with the resize state machine.
error = v->server_monitor_resize_done(v);
v->resize_status = VRS_DONE;
if (error == 0)
{
// If this resize was requested by the client mid-session
// (dynamic resize), we need to tell xrdp_mm that
// it's OK to continue with the resize state machine.
error = v->server_monitor_resize_done(v);
if (error == 0)
{
error = send_update_request_for_resize_status(v);
}
}
}
v->resize_status = VRS_DONE;
}
}
return error;
}
/**************************************************************************//**
* Looks for the forwarded screen layout in a framebuffer update request
*
* Looks for an ExtendedDesktopSize rectangle following a notification
* from the VNC server that the request has been forwarded to the real
* desktop. See rfbproto/pfbproto#32 for more info.
*
* @param v VNC object
* @return != 0 for error
*/
static int
lib_framebuffer_look_for_forwarded_layout(struct vnc *v)
{
int error;
struct vnc_screen_layout layout = {0};
int x = 0;
int y = 0;
error = find_matching_extended_rect(v,
rect_is_general_change,
&x,
&y,
&layout);
if (error == 0)
{
error = send_update_request_for_resize_status(v);
if (layout.count > 0)
{
if (vnc_screen_layouts_equal(&layout, &v->forwarded_layout))
{
LOG(LOG_LEVEL_DEBUG,
"VNC_RESIZE: VNC server forwarded resize complete");
free(v->forward_timer);
v->forward_timer = NULL;
v->server_layout = layout;
error = v->server_monitor_resize_done(v);
v->resize_status = VRS_DONE;
}
else
{
LOG(LOG_LEVEL_DEBUG,
"VNC_RESIZE: Ignored ExtendedDesktopSize %dx%d x=%d y=%d",
layout.total_width, layout.total_height, x, y);
// Delay for a little before we send another request for
// the size
g_sleep(100);
}
error = send_update_request_for_resize_status(v);
}
}
return error;
}
/******************************************************************************/
/*
* The VNC server has not actioned a forwarded resize request
*/
static int
forward_timer_expired(struct vnc *v)
{
LOG(LOG_LEVEL_WARNING, "VNC server forwarded resize timed out");
LOG(LOG_LEVEL_DEBUG,
"VNC_RESIZE: VNC server forwarded resize timed out");
free(v->forward_timer);
v->forward_timer = NULL;
v->resize_status = VRS_DONE;
int rv = v->server_monitor_resize_done(v);
if (rv == 0)
{
LOG(LOG_LEVEL_WARNING, "Resizing client to server");
rv = resize_client_to_server(v, 0);
}
return rv;
}
/******************************************************************************/
static int
lib_framebuffer_update(struct vnc *v)
@@ -1433,6 +1544,9 @@ lib_framebuffer_update(struct vnc *v)
layout.total_height = cy;
error = read_extended_desktop_size_rect(v, &layout);
/* If this is a reply to a request from us, x == 1 */
LOG(LOG_LEVEL_DEBUG,
"VNC_RESIZE: Read ExtendedDesktopSize %dx%d x=%d y=%d",
layout.total_width, layout.total_height, x, y);
if (error == 0 && x != 1)
{
if (!vnc_screen_layouts_equal(&v->server_layout, &layout))
@@ -1574,7 +1688,14 @@ lib_mod_process_message(struct vnc *v, struct stream *s)
break;
case VRS_WAITING_FOR_RESIZE_CONFIRM:
error = lib_framebuffer_waiting_for_resize_confirm(v);
if (v->forward_timer != NULL)
{
error = lib_framebuffer_look_for_forwarded_layout(v);
}
else
{
error = lib_framebuffer_waiting_for_resize_confirm(v);
}
break;
default:
@@ -2533,6 +2654,10 @@ lib_mod_get_wait_objs(struct vnc *v, tbus *read_objs, int *rcount,
trans_get_wait_objs_rw(v->trans, read_objs, rcount,
write_objs, wcount, timeout);
}
// Update timeout with any active timers
unsigned int now = g_get_elapsed_ms();
timers_oneshot_update_poll(v->forward_timer, now, timeout);
}
return 0;
@@ -2550,13 +2675,22 @@ lib_mod_check_wait_objs(struct vnc *v)
{
if (v->trans != 0)
{
rv = trans_check_wait_objs(v->trans);
if (rv != 0)
if ((rv = trans_check_wait_objs(v->trans)) != 0)
{
LOG(LOG_LEVEL_ERROR, "VNC server closed connection");
}
else
{
// Check timers
unsigned int now = g_get_elapsed_ms();
if (timers_oneshot_get_remaining(v->forward_timer, now) == 0)
{
rv = forward_timer_expired(v);
}
}
}
}
return rv;
}
vnc/vnc.h
+7
View File
@@ -31,6 +31,8 @@
#define CURRENT_MOD_VER 4
struct timers_oneshot;
/* Screen used for ExtendedDesktopSize / Set DesktopSize */
struct vnc_screen
{
@@ -188,6 +190,11 @@ struct vnc
struct vnc_screen_layout server_layout;
enum vnc_resize_status resize_status;
enum vnc_resize_support_status resize_supported;
/* forwarded resize */
// This occurs when the VNC server forwards a resize request
// elsewhere (RFB_EDS_REQUEST_FORWARDED)
struct timers_oneshot *forward_timer;
struct vnc_screen_layout forwarded_layout;
};
/*