Implement privileged input daemon, first version without handlers.

1 files changed, 147 insertions, 0 deletions

diff --git a/src/input/pvsprivinputd.cpp b/src/input/pvsprivinputd.cpp
new file mode 100644
index 0000000..3a5e1a8
--- /dev/null
+++ b/src/input/pvsprivinputd.cpp
@@ -0,0 +1,147 @@
+/*
+ # Copyright (c) 2009 - OpenSLX Project, Computer Center University of Freiburg
+ #
+ # This program is free software distributed under the GPL version 2.
+ # See http://openslx.org/COPYING
+ #
+ # If you have any feedback please consult http://openslx.org/feedback and
+ # send your suggestions, praise, or complaints to feedback@openslx.org
+ #
+ # General information about OpenSLX can be found at http://openslx.org/
+ # --------------------------------------------------------------------------
+ # pvsprivinputd.cpp:
+ #  - Handle privileged input events - daemon
+ # --------------------------------------------------------------------------
+ */
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <signal.h>
+#include <unistd.h>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <QtDebug>
+#include <QSettings>
+#include <QCoreApplication>
+#include <QStringList>
+#include <QSocketNotifier>
+#include "pvsPrivInputSocket.h"
+#include "pvsPrivInputHandler.h"
+
+using namespace std;
+
+#ifndef UNIX_PATH_MAX
+# define UNIX_PATH_MAX 108 /* according to unix(7) */
+#endif
+
+QByteArray socketPath;
+int sigintFds[2];
+
+static void unlinkSocket()
+{
+	if(!socketPath.isNull())
+	{
+		unlink(socketPath.constData());
+	}
+}
+
+static void onInterrupt(int)
+{
+	char buf[] = { '!' };
+	char msg[] = "SIGINT caught. Quitting.\n";
+	write(sigintFds[0], buf, 1);
+	write(1, msg, sizeof(msg)-1);
+}
+
+int main(int argc, char** argv)
+{
+	QCoreApplication app(argc, argv);
+	app.setApplicationName("pvsprivinputd");
+	app.setOrganizationName("openslx");
+
+	bool no_fork = app.arguments().contains("--no-fork", Qt::CaseInsensitive);
+	if(!no_fork)
+	{
+		pid_t pid;
+		pid_t sid;
+
+		pid = fork();
+		if(pid < 0)
+		{
+			qCritical("Could not fork: %s", strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+		if(pid > 0)
+		{
+			exit(EXIT_SUCCESS);
+		}
+
+		// We are now inside a child process.
+		// Detach from parent:
+		sid = setsid();
+		if(sid < 0)
+		{
+			qCritical("Could not detach from parent process: %s", strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+
+		// Change to some benign directory:
+		if(chdir("/") < 0)
+		{
+			qCritical("Could not change directory: %s", strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	// Okay, we are running as a daemon. Defer reopening standard file descriptors
+	// so we can report errors.
+
+	// Set the file creation mask to allow all processes to connect to
+	// the socket (access control is handled differently):
+	umask(0);
+
+	// Ignore SIGPIPE. Connection errors are handled internally.
+	// According to signal(2), the only error is that the signal number
+	// is invalid. This cannot happen.
+	signal(SIGPIPE, SIG_IGN);
+
+	// set up signal handling:
+	if(socketpair(AF_UNIX, SOCK_STREAM, 0, sigintFds) < 0)
+	{
+		qCritical("Could not set up signal handling. Giving up.");
+		exit(EXIT_FAILURE);
+	}
+	socketPath = pvsPrivInputGetSocketAddress().toLocal8Bit();
+	QSocketNotifier sigintWatcher(sigintFds[1], QSocketNotifier::Read);
+	QObject::connect(&sigintWatcher, SIGNAL(activated(int)), &app, SLOT(quit()));
+	signal(SIGINT, onInterrupt);
+
+	// Create our socket:
+	int sock = pvsPrivInputMakeServerSocket();
+	if(sock < 0)
+	{
+		exit(EXIT_FAILURE);
+	}
+
+	// Our setup is complete.
+	if(!no_fork)
+	{
+		// Reopen standard file descriptors:
+		freopen("/dev/null", "r", stdin);
+		freopen("/dev/null", "w", stderr);
+		freopen("/dev/null", "w", stdout);
+	}
+
+	// Install our main object
+	PVSPrivInputHandler handler(sock);
+
+	atexit(unlinkSocket);
+
+	// and run the main loop.
+	int ret = app.exec();
+
+	return ret;
+}