mirrors
/
xrdp
mirror of https://github.com/neutrinolabs/xrdp
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Don't tell the RDP client about unchanged clip data from the RFB side

This commit is contained in:
matt335672 2021-06-04 14:32:08 +01:00
parent fe28af93e8
commit f52d038d3e
1 changed files with 77 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

83
vnc/vnc_clip.c
View File

@ -33,6 +33,7 @@
#include "vnc.h"
#include "vnc_clip.h"
#include "string_calls.h"
#include "ssl_calls.h"
#include "rfb.h"
#include "log.h"
#include "trans.h"
@ -70,6 +71,16 @@ struct vnc_clipboard_data
bool_t startup_complete; /* is the startup sequence done (1.3.2.1) */
};
/**
* Summarise a stream contents in a way which allows two streams to
* be easily compared
*/
struct stream_characteristics
{
char digest[16];
int length;
};
#ifdef USE_DEVEL_LOGGING
/***************************************************************************//**
* Convert a CF_ constant to text
@ -338,6 +349,49 @@ handle_cb_format_list(struct vnc *v, int msg_flags, struct stream *s)
return rv;
}
/***************************************************************************//**
* Computes the characteristics of a stream.
*
* This can be used to tell if a stream has changed or two streams are
* the same
*
* @param s Stream
* @param[out] chars Resulting characteristics of stream
*/
static void
compute_stream_characteristics(const struct stream *s,
struct stream_characteristics *chars)
{
void *info = ssl_md5_info_create();
ssl_md5_clear(info);
if (s->data != NULL && s->end != NULL)
{
chars->length = (int)(s->end - s->data);
ssl_md5_transform(info, s->data, chars->length);
}
else
{
chars->length = 0;
}
ssl_md5_complete(info, chars->digest);
ssl_md5_info_delete(info);
}
/***************************************************************************//**
* Compare two stream characteristics structs for equality
*
* @param a characteristics of first stream
* @param b characteristics of second stream
* @result != 0 if characteristics are equal
*/
static int
stream_characteristics_equal(const struct stream_characteristics *a,
const struct stream_characteristics *b)
{
return (a->length == b->length &&
g_memcmp(a->digest, b->digest, sizeof(a->digest)) == 0);
}
/******************************************************************************/
static int
handle_cb_format_data_request(struct vnc *v, struct stream *s)
@ -938,6 +992,12 @@ vnc_clip_process_rfb_data(struct vnc *v)
}
else
{
struct stream_characteristics old_chars;
struct stream_characteristics new_chars;
/* Compute the characteristics of the existing data */
compute_stream_characteristics(vc->rfb_clip_s, &old_chars);
/* Lose any existing RFB clip data */
free_stream(vc->rfb_clip_s);
vc->rfb_clip_s = 0;
@ -959,13 +1019,24 @@ vnc_clip_process_rfb_data(struct vnc *v)
LOG(LOG_LEVEL_DEBUG, "Reading %d clip bytes from RFB", size);
rv = trans_force_read_s(v->trans, vc->rfb_clip_s, size);
}
}
}
/* startup_complete is only ever set if we're using the VNC clip facility */
if (rv == 0 && vc->startup_complete)
{
send_format_list(v);
/* Consider telling the RDP client about the update only if we've
* completed the startup handshake */
if (rv == 0 && vc->startup_complete)
{
/* Has the data actually changed ? */
compute_stream_characteristics(vc->rfb_clip_s, &new_chars);
if (stream_characteristics_equal(&old_chars, &new_chars))
{
LOG_DEVEL(LOG_LEVEL_INFO, "RFB Clip data is unchanged");
}
else
{
LOG_DEVEL(LOG_LEVEL_INFO, "RFB Clip data is updated");
send_format_list(v);
}
}
}
}
free_stream(s);