From 1e321f0959643f905a3af2505f90c838293f37ca Mon Sep 17 00:00:00 2001
From: Gerd von Egidy <gerd@egidy.de>
Date: Tue, 29 Apr 2014 00:05:39 +0200
Subject: [PATCH] Fix possible race when the reload-process determines it's
 parent pid and the true parent has ended

Now transfers the true parent pid as parameter to --reload-internal.

Refs #5788
---
 icinga-app/icinga.cpp    | 11 ++++++-----
 lib/base/application.cpp |  7 ++++++-
 lib/base/utility.cpp     | 15 ---------------
 lib/base/utility.h       |  1 -
 4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/icinga-app/icinga.cpp b/icinga-app/icinga.cpp
index 4208bed6a..8c7940ca1 100644
--- a/icinga-app/icinga.cpp
+++ b/icinga-app/icinga.cpp
@@ -195,8 +195,8 @@ static bool Daemonize(const String& stderrFile)
 static void TerminateAndWaitForEnd(pid_t target)
 {
 #ifndef _WIN32
-	// allow 15 seconds timeout
-	double timeout = Utility::GetTime() + 15;
+	// allow 30 seconds timeout
+	double timeout = Utility::GetTime() + 30;
 
 	int ret = kill(target, SIGTERM);
 
@@ -279,8 +279,8 @@ int Main(void)
 		("validate,C", "exit after validating the configuration")
 		("debug,x", "enable debugging")
 		("errorlog,e", po::value<std::string>(), "log fatal errors to the specified log file (only works in combination with --daemonize)")
-		("reload-internal", "used internally to implement config reload: do not call manually, send SIGHUP instead")
 #ifndef _WIN32
+		("reload-internal", po::value<int>(), "used internally to implement config reload: do not call manually, send SIGHUP instead")
 		("daemonize,d", "detach from the controlling terminal")
 		("user,u", po::value<std::string>(), "user to run Icinga as")
 		("group,g", po::value<std::string>(), "group to run Icinga as")
@@ -450,8 +450,9 @@ int Main(void)
 	}
 
 	if(g_AppParams.count("reload-internal")) {
-		Log(LogInformation, "icinga-app", "Terminating previous instance of Icinga (PID " + Convert::ToString(Utility::GetParentPid()) + ")");
-		TerminateAndWaitForEnd(Utility::GetParentPid());
+		int parentpid = g_AppParams["reload-internal"].as<int>();
+		Log(LogInformation, "icinga-app", "Terminating previous instance of Icinga (PID " + Convert::ToString(parentpid) + ")");
+		TerminateAndWaitForEnd(parentpid);
 		Log(LogInformation, "icinga-app", "Previous instance has ended, taking over now.");
 	}
 
diff --git a/lib/base/application.cpp b/lib/base/application.cpp
index 6cef2b83f..5a5f36757 100644
--- a/lib/base/application.cpp
+++ b/lib/base/application.cpp
@@ -26,6 +26,7 @@
 #include "base/utility.h"
 #include "base/debug.h"
 #include "base/type.h"
+#include "base/convert.h"
 #include "base/scriptvariable.h"
 #include "icinga-version.h"
 #include <sstream>
@@ -282,10 +283,14 @@ void Application::StartReloadProcess(void) const
 	std::vector<String> args;
 	args.push_back(GetExePath(m_ArgV[0]));
 
-	for (int i=1; i < Application::GetArgC(); i++)
+	for (int i=1; i < Application::GetArgC(); i++) {
 		if (std::string(Application::GetArgV()[i]) != "--reload-internal")
 			args.push_back(Application::GetArgV()[i]);
+		else
+			i++;     // the next parameter after --reload-internal is the pid, remove that too
+	}
 	args.push_back("--reload-internal");
+	args.push_back(Convert::ToString(Utility::GetPid()));
 
 	Process::Ptr process = make_shared<Process>(args);
 
diff --git a/lib/base/utility.cpp b/lib/base/utility.cpp
index dc3c8232b..56559fea2 100644
--- a/lib/base/utility.cpp
+++ b/lib/base/utility.cpp
@@ -331,21 +331,6 @@ pid_t Utility::GetPid(void)
 #endif /* _WIN32 */
 }
 
-/**
- * Returns the ID of the parent process.
- *
- * @returns The PID.
- */
-pid_t Utility::GetParentPid(void)
-{
-#ifndef _WIN32
-	return getppid();
-#else /* _WIN32 */
-	// TODO
-	return 0;
-#endif /* _WIN32 */
-}
-
 /**
  * Sleeps for the specified amount of time.
  *
diff --git a/lib/base/utility.h b/lib/base/utility.h
index ada33d43a..f8c05a5fe 100644
--- a/lib/base/utility.h
+++ b/lib/base/utility.h
@@ -74,7 +74,6 @@ public:
 	static double GetTime(void);
 
 	static pid_t GetPid(void);
-	static pid_t GetParentPid(void);
 
 	static void Sleep(double timeout);