There is no need to LoadLibrary and GetProcAddress to get pointers to
NtDelayExecution or NtSetTimerResolution. These functions don't have
prototypes in any SDK header, but they are exported in ntdll.dll and
we can simply declare the prototype and link ntdll.
There is also no chance that the functions do not exist: I checked an
old install of Windows NT 4.0 and both of these functions exist.
Also used NtSetTimerResolution instead of ZeSetTimerResolution for
consistency (they are the same).
Also changed system timer resolution log message units to μs with
one decimal digit for readability. This is the actual amount of
precision available to us.
According to MSDN documentation for CreateEnvironmentBlock, "[i]f the
environment block is passed to CreateProcessAsUser, you must also
specify the CREATE_UNICODE_ENVIRONMENT flag."
Also pass DETACHED_PROCESS because the host is a GUI application and
doesn't use the console.
Since with the service, we are already running as SYSTEM, we don't need
to use dupeSystemProcessToken to get the token for SYSTEM. This removes
the need for having SeDebugPrivilege, SeTcbPrivilege, and
SeAssignPrimaryTokenPrivilege, or otherwise doing sketchy things.
Furthermore, we now only open the token with the privileges we actually
need.
This allows the process to be terminated without resorting to
TerminateProcess. With some fixes, this allows the notification icon to be
removed when the service is restarted.
Furthermore, instead of sending WM_DESTROY to fool the window into believing
it's being destroyed, we actually call DestroyWindow now.
For adjacent changed regions, we actually use the bounding box for the
entire polygon. This may result in more area being damaged than strictly
necessary, but is nevertheless desirable since it reduces the number of
rectangles.
The windows hook WH_MOUSE_LL is called in such a way that any delay in
processing causes a system wide stall. This change spawns an extra
thread which waits on an event set by the hook which is then used to
call the callback with an artifical limit of 1000Hz.
Before we try and perhaps fail to init DXGI, we should print out what
the device is so that when there is an error report we can immediately
see if the user has the QXL device attached still.
While it's correct for DXGI to use a asyncronous waitFrame model, other
capture interfaces such as NvFBC it is not correct. This change allows
the capture interface to specify which is more correct for it and moves
the waitFrame/post into the main thread if async is not desired.
This changes the host to use a seperate pool of LGMP memory for cursor
positionl updates without shape information helping to prevent
corruption of the shape entries if they are still pending. While this is
not a perfect solution it resolves the issue without making major
changes to LGMP during the RC phase we are currently in.
Before, we only break out of the current row when a change is detected,
and all subsequent rows are still scanned. Now we break out of the entire
loop. This should make change detection ever so slightly faster.
Testing shows that `D3DKMTSetProcessSchedulingPriorityClass` has a
positive performance impact for NvFBC as well as DXGI, as such always
try to boost the priority for the windows host.
This so called "enhanced" event logic is completely flawed and can never
work correctly, better to strip it out and put our faith in windows to
handle the events for us.
And yes, I am fully aware I wrote the utter trash in the first place :)
People often miss the warnings about invalid arguments in their command
line, this last minute patch attempts to address this by making
warnings, errors, fixme's and fatal errors stand out if stdout is a TTY.
If the guest VM is not showing a cursor when it starts such as on the
Windows login screen, the client never gets the current position of the
cursor, which prevents the client from attempting to send mouse
movements. This change ensures the client gets the mouse location on
startup.
We should only advance the pointerIndex if the buffer was not swapped
out for storage. This is to ensure that we do not overwrite cursor
memory that the client(s) may still be using.
This reverts commit d82f2e510d.
While the proposed change is more correct, it breaks the generation of
the file due to failure to locate the resource files, such as
`resources/icon.ico`.
When a new cursor shape is provided by the capture interface we need to
retain a copy of it incase a new client connects which will not yet have
the cursor shape. The logic here was flawed causing the wrong shape to
be sent to a new client in some instances.
This change adds an average function to time how long it takes the GPU
to copy and map the texture, and then uses this average to sleep for 80%
of this average lowering CPU usage and potentially decreasing lock
contention.
It has been detemined that a failure to init NvFBC causes a 20-30%
performance penalty on non NvFBC supported hardware (GeForce) when using
DXGI, as such reverse the order and default to using DXGI as our first
option.
If NvFBC is still desired, pr #500 added the option `app:capture` which
can be used to force NvFBC.
One of the most common issues reported in the support channels is the
IVSHMEM size being too small. This change adds a calculation to
determine an optimal size and uses the new `os_showMessage` platform
method to display a message box to the user with the error.
Since we now let the mouse hook linger until the process is killed, the
cursor event that the hook signals may now be null, as the capture could
have stopped. If the hook fires during this time, a crash occurs.
Instead of converting every SID to string with ConvertSidToStringSidA
and compare it with the magical SID string for local system with strcmp,
we could instead create the local system SID and compare directly with
EqualSid.
We don't actually have any handles that should be inherited, so specifying
TRUE for bInheritHandles to CreateProcessAsUserA is pointless.
Furthermore, according to MSDN, "[y]ou cannot inherit handles across
sessions," and we are spawning the host in a different session, so this
is even more pointless.
Instead of doing ShellExecute from the service, we instead get the token
of the currently logged in user, and do CreateProcessAsUserA to run
notepad with that token. This should be safe.
Also for failure to parse command line. For these errors, restarting
with exponential backoff will not help: no amount of restarting the
service could possibly make the ivshmem device exist or larger, so
we shouldn't try.
Certain users of Radeon cards have observed that the host fails to start
at boot, with D3D11CreateDevice failing with HSTATUS 0x887a0004, which
translates to "The specified device interface or feature level is not
supported on this system."
This failure results in a LG_HOST_EXIT_FAILED exit code, which the service
does not attempt to restart. The user has to manually restart the service
for the host application to work.
These users reported that the host application started fine on
B2. This strongly suggests that the fix to enable capturing the login
screen made the host application start too early during the boot process,
and the graphics driver did not have time to initialize fully.
This PR allows the service to retry a few times on LG_HOST_EXIT_FAILED,
with exponential backoff, before giving up. This should cover this bug
and other similar bugs related to the early initialization which I do not
have logs for.
This commit introduces a new option, app:capture, which can be set to
either DXGI or NvFBC to force the host application to use that backend.
This is very useful for testing DXGI on Quadro cards, which would default
to running with NvFBC.
This is needed for proper cleanup.
Freeing the capture interface also avoids a crash when using the NvFBC
backend. This is because we moved the mouse hook removal to nvfbc_free.
If nvfbc_free is not called before we start freeing LGMP memory, the
mouse hook would end up writing the cursor position into an invalid
memory address, causing an access violation.
This will allow us to add an option to disable the screensaver on the client
when an application in the guest requests it. This behaviour may be useful
when the guest is doing media playback.
The mouse hook code is very fragile, and we would like to avoid unhooking
and re-hooking as much as possible.
After this commit, this is done only once, and the hook and 1x1 window is
only destroyed upon exit. This, of course, comes with the downside of
the slight performance penalty if the guest machine is used directly while
the host is running and the client is not running.
Moving NvFBCToSysSetup to nvfbc_init means that when the pointer thread
fails to be created, NvFBCToSysRelease needs to be called.
To resolve such cleanup issues in the future, we instead call nvfbc_deinit,
which should cleanup everything that needs to be cleaned up. fails.
When NvFBCToSysCapture reports recreation is required, we return
CAPTURE_RESULT_REINIT, which eventually calls nvfbc_deinit and then
nvfbc_init.
However, the NvFBC object is actually created in nvfbc_create, which
means the NvFBC object is never actually recreated. The result is an
endless cycle of NvFBC asking for recreation. This commonly manifests
as the client waiting endlessly for the host when the guest machine
reboots.
In this commit, the NvFBC object creation is moved into nvfbc_init,
and when recreation is required, it will actually be recreated.
mouseHook_install and dwmForceComposition both create threads, but these
are only freed in nvfbc_deinit which is not called if nvfbc_init fails.
These should be freed if the pointer thread fails to be created, as
nothing else could be cleaning it up.
Instead of using %windir%\Temp, which is not accessible by default and
contains a lot of unrelated files, as the location for our log files,
this commit moves it to %ProgramData%\Looking Glass (host), which will
be a dedicated directory just for the LG host log files. This applies
to both the host application logs and the service logs.
Also, we now switched to using PathCombineA from shlwapi.dll instead
of using snprintf, which greatly simplifies the code. PathCombineA
guarantees that the path would not overflow a buffer of MAX_PATH.
Before this commit, the NvFBC backend only generated the first cursor
position update when the mouse moves. Therefore, if the user does
not move the mouse, the cursor will be shown at (0, 0), which is not
ideal.
This commit changes this behaviour to unconditionally generate a
cursor update when the mouse hook initializes.
Nehalem is the minimum requirement for the host application as it makes
use of SSE4.1 instructions, as such we should default to compling with
it instead of `-march=native` so that when the binary is distributed it
will operate on foreign systems.
Fixed#416
Before this change, the log is buffered, so if the host application exits
for any reason, it usually would not show up in the log file immediately,
and the service has to be restarted for the logs to be flushed.
This commit disables the buffering so that any log entries shows up
immediately.
This is because we keep track of the top-left corner of the cursor, not
the location of the hotspot. When the cursor shape changes, the hotspot
location may also change. When it does, the position of the top-left
corner changes and requires an update.
In the case that we do not have the current cursor position, which
happens on startup, we do not generate this update.
NvFBC is unable to capture certain applications that bypasses the DWM
compositor, for example, Firefox playing video in full screen. This
has been a known issue for a long time with Nvidia's ShadowPlay, see:
* https://www.nvidia.com/en-us/geforce/forums/geforce-experience/14/233709/
* https://crbug.com/609857
Nvidia won't fix this, but there are workarounds. For example, we
create a transparent 1x1 layered window, which forces desktop composition
to be enabled.
Note that SetLayeredWindowAttributes also supports alpha-based transparency,
but setting transparency to 0 will cause DWM to skip composition. We could
use a transparency of 1, but this ruins the image by the slightest bit,
which is unacceptable. Therefore, we must use chroma key-based
transparency, which tricks DWM into compositing despite being fully
transparent.
Basically, this creates a separate thread for the mouse events, and this
thread detects that the desktop has changed (say to the secure desktop),
and unhooks, switches to the new desktop, and then rehooks.
This allows the cursor location to be updated while using NvFBC on secure
desktop and the login screen.
WTSGetActiveConsoleSessionId will return a session even if it's not logged in,
unlike our old GetInteractiveSessionID function. Launching looking glass on
such a console session will allow the login screen to be captured.
Note that WTSGetActiveConsoleSessionId() will return 0xFFFFFFFF if there are
no sessions attached.
To quote MSDN documentation:
> The lpApplicationName parameter can be NULL, in which case the executable
> name must be the first white space–delimited string in lpCommandLine. If
> the executable or path name has a space in it, there is a risk that a
> different executable could be run because of the way the function parses
> spaces. The following example is dangerous because the function will
> attempt to run "Program.exe", if it exists, instead of "MyApp.exe".
>
> LPTSTR szCmdline[] = _tcsdup(TEXT("C:\\Program Files\\MyApp"));
> CreateProcessAsUser(hToken, NULL, szCmdline, /*...*/ );
>
> If a malicious user were to create an application called "Program.exe" on
> a system, any program that incorrectly calls CreateProcessAsUser using the
> Program Files directory will run this application instead of the intended
> application.
>
> To avoid this problem, do not pass NULL for lpApplicationName.
So instead, we pass the executable to lpApplicationName instead, which avoids
the issue. MSDN says:
> The lpCommandLine parameter can be NULL. In that case, the function uses
> the string pointed to by lpApplicationName as the command line.
This also avoids the strdup since lpApplicationName is LPCSTR unlike
lpCommandLine which is LPSTR.
It shouldn't have any effect, since the host application is created with
the token, and there is no need for the service itself to impersonate.
In practice, removal doesn't appear to have any effect on the ability to
capture privileged things like secure desktop.
Use the process handle returned by CreateProcessAsUserA to wait on the
process. This results in faster response times and less polling.
For example, it now restarts instantly when UAC is activated.
This also removes the call to OpenProcess and rendering the mutex unnecessary.
As a bonus, it should fix#298.
The host process will be changed to return these codes, from which the
service process could decide whether to exit or restart the process and log.
Note that on Windows, return values are 32-bit unlike POSIX which is only 8.
This makes it a compile-time error to call a function that semantically
takes no parameters with a nonzero number of arguments.
Previously, such code would still compile, but risk blowing up the stack
if a compiler chose to use something other than caller-cleanup calling
conventions.
There is no need to allocate a buffer for each message as the client is
only required to show the latest version of the cursor. Whie the logic
should prevent cursor corruption, it's not guaranteed, however this is
not a problem as this can only happen if the client is lagging behind
and as such when it gets another update message it will re-read the
now new shape anyway.
This commit bumps the KVMFR protocol version as it adds additional
hotspot x & y fields to the KVMFRCursor struct. This corrects the issue
of invalid alignment of the local mouse when the shape has an offset
such as the 'I' beam.
Now that it's recommended to run LG as the `SYSTEM` user, launching an
application to read the log file is dangerous as it will be launched
with the same access rights (`SYSTEM`). Instead so as Microsoft
recommends and only present a message box with the information.
Experimental, use at your own peril!
This commit adds the ability for the LG host to install and launch with
Windows as a system service.
To install simply run `looking-glass-host.exe InstallService` or
conversely to uninstall `looking-glass-host.exe UninstallService`.
SafeRelease was really useless, derefencing the smart pointers through
the use of & releases the value before SafeRelease get's to it. Instead
either allow the destructor to handle it's release, or explicityly
release it by assigning NULL
Contrary to the MS documentation, benchmarking shows a substantial
increase in performance when releasing the captured frame as soon
as possible. This change makes it possible to achieve 60FPS at 4K
resolutions.
Pass -DUNICODE as a CFLAG. The visual studio project asks for
a unicode (wide-string) build, but the unix makefile did not.
This fixes the build on msys2.
* [host] rename min() to LG_MIN()
* [host] format string type fixes, %Ix doesn't exist in mingw
* [host] DXGI minor fixes
* [host] mingw lacks media foundation api headers and QISearch
Writing to shared memory is much faster then reading as the shared
memory is not cached, this change ensures we are using a local copy
of the header performing the final update all in one go.
This will help frame delivery to the host arrive on time, as well as
allow lower latency with a higher host refresh rate.
Data offset addresses are now also pre-calculated rather then
updated on every frame.
NvFBC will wait forever for a change if nothing has changed, instead use
a timeout so that if the guest has re-connected it doesn't stall waiting
for a guest update.
For this to function correctly the display scaling in the nvidia control
panel must be set to "No scaling", failure to do so will cause incorrect
window cropping. This is due to the inability to capture a non-scaled
image using NvFBC.
DXGI doesn't like to restart too fast, com exceptions are logged and the
duplication device fails to create with an E_ACCESS_DENIED error. Adding
a 200ms sleep between teardown and re-init resolves this issue.
Note: This class will be entirely re-written when I find some time,
it is very poorly implemented, full of assumptions and creates a new
texture for every single frame 🤦.
