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Fix deferred telemetry pipe attach for RDP sessions #1992

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Merged
tyrielv merged 1 commit into from
Jun 1, 2026
+141 −27
Merged

Fix deferred telemetry pipe attach for RDP sessions #1992

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60 changes: 56 additions & 4 deletions GVFS/GVFS.Platform.Windows/CurrentUser.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -134,7 +134,7 @@ public bool RunAs(string processName, string args)
if (CreateEnvironmentBlock(ref environment, duplicate, false))
{
STARTUP_INFO info = new STARTUP_INFO();
info.Length = Marshal.SizeOf(typeof(STARTUP_INFO));
info.Length = Marshal.SizeOf<STARTUP_INFO>();

PROCESS_INFORMATION procInfo = new PROCESS_INFORMATION();
if (CreateProcessAsUser(
Expand Down Expand Up @@ -193,6 +193,55 @@ public bool RunAs(string processName, string args)
return false;
}

/// <summary>
/// Returns session IDs for sessions that have a logged-in user
/// whose token can be queried via <c>WTSQueryUserToken</c>.
/// </summary>
/// <remarks>
/// <para>
/// WTS session states relevant to telemetry pipe attachment:
/// </para>
/// <list type="table">
/// <listheader><term>State</term><description>Meaning</description></listheader>
/// <item><term>Active</term><description>
/// User logged in, session connected (console or RDP).
/// Has a valid user token. This is the primary case.
/// </description></item>
/// <item><term>Connected</term><description>
/// Client attached but no user logged in (e.g. the console
/// session showing the Windows login screen on a Cloud PC).
/// No user token — <c>WTSQueryUserToken</c> will fail.
/// </description></item>
/// <item><term>Disconnected</term><description>
/// User logged in but client disconnected (e.g. closed RDP
/// window without logging off). The user's profile, processes,
/// and token are still available. Included so the service can
/// attach telemetry even when no client is actively connected.
/// </description></item>
/// </list>
/// <para>
/// Session 0 is the services session and never has a user token,
/// even when its state is Disconnected. Excluded by the ID > 0
/// guard.
/// </para>
/// </remarks>
public static List<int> GetInteractiveSessionIds(ITracer tracer)
{
List<int> sessionIds = new List<int>();
List<WTS_SESSION_INFO> sessions = ListSessions(tracer);
foreach (WTS_SESSION_INFO session in sessions)
{
if (session.SessionID > 0 &&
(session.State == ConnectionState.Active ||
session.State == ConnectionState.Disconnected))
{
sessionIds.Add(session.SessionID);
}
}

return sessionIds;
}

public void Dispose()
{
if (this.token != IntPtr.Zero)
Expand All @@ -216,7 +265,10 @@ private static IntPtr GetCurrentUserToken(ITracer tracer, int sessionId)
}
else
{
TraceWin32Error(tracer, string.Format("Unable to query user token from session '{0}'.", sessionId));
// Warning, not error: sessions without a logged-in user
// (e.g. the console session on a Cloud PC) are expected.
Win32Exception e = new Win32Exception(Marshal.GetLastWin32Error());
tracer.RelatedWarning("Unable to query user token from session '{0}'. Exception: {1}", sessionId, e.Message);
}

return IntPtr.Zero;
Expand All @@ -234,12 +286,12 @@ private static List<WTS_SESSION_INFO> ListSessions(ITracer tracer)
int retval = WTSEnumerateSessions(IntPtr.Zero, 0, 1, ref sessionInfo, ref count);
if (retval != 0)
{
int dataSize = Marshal.SizeOf(typeof(WTS_SESSION_INFO));
int dataSize = Marshal.SizeOf<WTS_SESSION_INFO>();
long current = sessionInfo.ToInt64();

for (int i = 0; i < count; i++)
{
WTS_SESSION_INFO si = (WTS_SESSION_INFO)Marshal.PtrToStructure((IntPtr)current, typeof(WTS_SESSION_INFO));
WTS_SESSION_INFO si = Marshal.PtrToStructure<WTS_SESSION_INFO>((IntPtr)current);
current += dataSize;

output.Add(si);
Expand Down
108 changes: 85 additions & 23 deletions GVFS/GVFS.Service/GVFSService.Windows.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
using GVFS.Platform.Windows;
using GVFS.Service.Handlers;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.AccessControl;
Expand Down Expand Up @@ -46,6 +47,46 @@ public void Run()
metadata.Add("Version", ProcessHelper.GetCurrentProcessVersion());
this.tracer.RelatedEvent(EventLevel.Informational, $"{nameof(GVFSService)}_{nameof(this.Run)}", metadata);

// Set up deferred telemetry pipe attachment FIRST, before any
// telemetry-emitting work (particularly PendingUpgradeHandler,
// whose Deferred/Complete events we want to capture).
//
// The service runs as SYSTEM and can't read the user's global
// git config (where gvfs.telemetry-pipe is configured) at
// startup. The DeferredTelemetryAttacher adds a
// BufferingTelemetryListener that captures events in memory,
// then replays them once the real pipe listener attaches.
//
// Three attach paths exist:
// 1. TryAttachTelemetryPipeForAnySessions() below — tries
// all Active/Disconnected sessions immediately.
// 2. OnSessionChange (SessionLogon) — fires when a new user
// logs in after the service is already running.
// 3. StartRetryTimer — periodic retry (10s, 30s, 1m, 5m)
// as a fallback, reads system config only (no user
// config available without a session to impersonate).
string gitBinRoot = GVFSPlatform.Instance.GitInstallation.GetInstalledGitBinPath();
if (!string.IsNullOrEmpty(gitBinRoot))
{
this.telemetryAttacher = new DeferredTelemetryAttacher(
this.tracer,
GVFSConstants.Service.ServiceName,
enlistmentId: null,
mountId: null);
this.telemetryAttacher.StartRetryTimer(gitBinRoot);

// If a user is already logged in (e.g. service restart
// during active session), try attaching immediately by
// enumerating all interactive sessions. This is needed
// because WTSGetActiveConsoleSessionId only returns the
// physical console session, which on Cloud PCs / DevBoxes
// (RDP-only) has no logged-in user. The actual user is
// in an RDP session that the console-only check misses.
// SessionLogon events also won't fire for sessions that
// were already established before the service started.
this.TryAttachTelemetryPipeForAnySessions();
}

// Check for a staged upgrade before doing anything else.
// If no GVFS.Mount processes are running (typical at boot or after
// unmount-all), copy staged files in-place and proceed normally.
Expand Down Expand Up @@ -77,29 +118,6 @@ public void Run()
{
this.CheckEnableGitStatusCacheTokenFile();

// Set up deferred telemetry pipe attachment. The service
// runs as SYSTEM and can't read the user's global git
// config at startup, so the daemon listener can't be
// created in the JsonTracer constructor.
string gitBinRoot = GVFSPlatform.Instance.GitInstallation.GetInstalledGitBinPath();
if (!string.IsNullOrEmpty(gitBinRoot))
{
this.telemetryAttacher = new DeferredTelemetryAttacher(
this.tracer,
GVFSConstants.Service.ServiceName,
enlistmentId: null,
mountId: null);
this.telemetryAttacher.StartRetryTimer(gitBinRoot);

// If a user is already logged in (e.g. service restart
// during active session), try attaching immediately.
int activeSession = NativeMethods.GetActiveConsoleSessionId();
if (activeSession > 0)
{
this.TryAttachTelemetryPipeForSession(activeSession);
}
}

using (ITracer activity = this.tracer.StartActivity("EnsurePrjFltHealthy", EventLevel.Informational))
{
// Make a best-effort to enable PrjFlt. Continue even if it fails.
Expand Down Expand Up @@ -475,6 +493,50 @@ private void TryAttachTelemetryPipeForSession(int sessionId)
}
}

/// <summary>
/// Enumerates all interactive sessions (Active and Disconnected)
/// and tries to attach the telemetry pipe using each session's
/// user profile. Stops on the first successful attach.
/// </summary>
/// <remarks>
/// This method exists because the console-only check
/// (<c>WTSGetActiveConsoleSessionId</c>) fails on Cloud PCs and
/// RDP-only machines where the console session is in the Connected
/// state (login screen, no user). Disconnected sessions are also
/// checked because an RDP user who disconnected without logging
/// off still has a valid token and git config.
/// </remarks>
private void TryAttachTelemetryPipeForAnySessions()
{
if (this.telemetryAttacher == null || this.telemetryAttacher.IsAttached)
{
return;
}

List<int> sessionIds = CurrentUser.GetInteractiveSessionIds(this.tracer);
if (sessionIds.Count == 0)
{
this.tracer.RelatedInfo("TryAttachTelemetryPipeForAnySessions: No interactive sessions found");
return;
}

foreach (int sessionId in sessionIds)
{
this.TryAttachTelemetryPipeForSession(sessionId);
if (this.telemetryAttacher.IsAttached)
{
break;
}
}

if (!this.telemetryAttacher.IsAttached)
{
this.tracer.RelatedWarning(
"TryAttachTelemetryPipeForAnySessions: Could not attach from any of {0} interactive session(s)",
sessionIds.Count);
}
}

private DirectorySecurity GetServiceDirectorySecurity(string serviceDataRootPath)
{
DirectorySecurity serviceDataRootSecurity;
Expand Down
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