From 9f000842951f6b5cb40208e9254c50ec56f143e6 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Fri, 10 Feb 2017 00:22:03 +0100
Subject: os/xdmcp: Just send XDMCP keepalive packets once every three minute
Backported from X.org:
commit db1089eafc1c5371fa0030202de588d2e2b4f8e5
Author: Keith Packard <keithp@keithp.com>
Date: Mon Sep 21 07:16:17 2015 +0100
os/xdmcp: Just send XDMCP keepalive packets once every three minutes
There was a complicated scheme to increase the time between keepalives
from 3 minutes up to as much as 24 hours in an attempt to reduce
network traffic from idle X terminals. X terminals receiving X
traffic, or receiving user input would use the 3 minute value; X
terminals without any network traffic would use a longer value.
However, this was actually broken -- any activity in the X server,
either client requests or user input, would end up resetting the
keepalive timeout, so a user mashing on the keyboard would never
discover that the XDMCP master had disappeared and have the session
terminated, which was precisely the design goal of the XDMCP keepalive
mechanism.
Instead of attempting to fix this, accept the cost of a pair of XDMCP
packets once every three minutes and just perform keepalives
regularly.
This will also make reworking the block and wakeup handler APIs to
eliminate select masks easier.
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
---
nx-X11/programs/Xserver/os/xdmcp.c | 24 ++----------------------
1 file changed, 2 insertions(+), 22 deletions(-)
(limited to 'nx-X11')
diff --git a/nx-X11/programs/Xserver/os/xdmcp.c b/nx-X11/programs/Xserver/os/xdmcp.c
index 83e234b43..c4b71f6ec 100644
--- a/nx-X11/programs/Xserver/os/xdmcp.c
+++ b/nx-X11/programs/Xserver/os/xdmcp.c
@@ -88,8 +88,6 @@ static int req_socklen;
static CARD32 SessionID;
static CARD32 timeOutTime;
static int timeOutRtx;
-static CARD32 defaultKeepaliveDormancy = XDM_DEF_DORMANCY;
-static CARD32 keepaliveDormancy = XDM_DEF_DORMANCY;
static CARD16 DisplayNumber;
static xdmcp_states XDM_INIT_STATE = XDM_OFF;
#ifdef HASXDMAUTH
@@ -643,6 +641,7 @@ XdmcpOpenDisplay(int sock)
if (state != XDM_AWAIT_MANAGE_RESPONSE)
return;
state = XDM_RUN_SESSION;
+ timeOutTime = GetTimeInMillis() + XDM_DEF_DORMANCY * 1000;
sessionSocket = sock;
}
@@ -706,7 +705,6 @@ XdmcpWakeupHandler(
void * pReadmask)
{
fd_set* LastSelectMask = (fd_set*)pReadmask;
- fd_set devicesReadable;
#ifdef NX_TRANS_SOCKET
@@ -731,16 +729,6 @@ XdmcpWakeupHandler(
FD_CLR(xdmcpSocket6, LastSelectMask);
}
#endif
- XFD_ANDSET(&devicesReadable, LastSelectMask, &EnabledDevices);
- if (XFD_ANYSET(&devicesReadable))
- {
- if (state == XDM_AWAIT_USER_INPUT)
- restart();
- else if (state == XDM_RUN_SESSION)
- keepaliveDormancy = defaultKeepaliveDormancy;
- }
- if (XFD_ANYSET(&AllClients) && state == XDM_RUN_SESSION)
- timeOutTime = GetTimeInMillis() + keepaliveDormancy * 1000;
}
else if (timeOutTime && (int) (GetTimeInMillis() - timeOutTime) >= 0)
{
@@ -1428,16 +1416,8 @@ recv_alive_msg (unsigned length)
{
if (SessionRunning && AliveSessionID == SessionID)
{
- /* backoff dormancy period */
state = XDM_RUN_SESSION;
- if ((GetTimeInMillis() - lastDeviceEventTime.milliseconds) >
- keepaliveDormancy * 1000)
- {
- keepaliveDormancy <<= 1;
- if (keepaliveDormancy > XDM_MAX_DORMANCY)
- keepaliveDormancy = XDM_MAX_DORMANCY;
- }
- timeOutTime = GetTimeInMillis() + keepaliveDormancy * 1000;
+ timeOutTime = GetTimeInMillis() + XDM_DEF_DORMANCY * 1000;
}
else
{
--
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