Implement log targets for pvsprivinputd

Also:
- add command line options and usage message.
- change --no-fork to --daemon to bring it in line with the
  pvs daemon.

1 files changed, 110 insertions, 6 deletions

diff --git a/src/input/pvsprivinputd.cpp b/src/input/pvsprivinputd.cpp
index 2f19d90..e6ae155 100644
--- a/src/input/pvsprivinputd.cpp
+++ b/src/input/pvsprivinputd.cpp
@@ -22,8 +22,10 @@
 #include <unistd.h>
 #include <cerrno>
 #include <cstdlib>
+#include <cstdio>
 #include <cstring>
 #include <QtDebug>
+#include <QFileInfo>
 #include <QSettings>
 #include <QCoreApplication>
 #include <QStringList>
@@ -32,6 +34,7 @@
 #include "pvsPrivInputSocket.h"
 #include "pvsPrivInputHandler.h"
 #include "pvsPrivInputSignalHandler.h"
+#include "pvsSyslog.h"
 
 using namespace std;
 
@@ -42,6 +45,9 @@ using namespace std;
 QByteArray socketPath;
 int signalFds[2];
 
+QTextStream qout(stdout, QIODevice::WriteOnly);
+QTextStream qerr(stderr, QIODevice::WriteOnly);
+
 static void unlinkSocket()
 {
 	if(!socketPath.isNull())
@@ -55,13 +61,70 @@ static void onCaughtSignal(int signum)
 	pvsPrivInputSendMessage(signalFds[0], &signum, sizeof(signum), 0);
 }
 
+static void usage()
+{
+	qout << QObject::tr(
+			"Usage: %1 [--help|-h] [--daemon|-d] [--log=<Logger>|-l<Logger>]\n"
+			"\n"
+			"Options:\n"
+			"  --help, -h     Show this message\n"
+			"  --daemon, -d   Run in background\n"
+			"  --log=<Logger>,\n"
+			"  -l<Logger>     Redirect all output to <Logger>\n"
+			"                 valid values are:\n"
+			"                   - any file name\n"
+			"                   - `syslog' to redirect output to the system log\n"
+			"                   - `null' to discard output (default)\n"
+			"                 (without quotes)\n"
+			"\n"
+			"Signals:\n"
+			"  SIGINT, SIGTERM (or press Ctrl+C when run in foreground)\n"
+			"                 Quit\n"
+			"  SIGHUP         Reload configuration and cached user data\n").arg(qApp->arguments().at(0)) << flush;
+}
+
 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);
+	bool no_fork = true;
+	QString logTarget = "null";
+
+	foreach(QString arg, app.arguments().mid(1))
+	{
+		if(arg == "--daemon" || arg == "-d")
+		{
+			no_fork = false;
+		}
+		else if(arg.startsWith("-l"))
+		{
+			logTarget = arg.mid(2);
+		}
+		else if(arg.startsWith("--log="))
+		{
+			logTarget = arg.mid(6);
+		}
+		else if(arg == "--help" || arg == "-h")
+		{
+			usage();
+			return EXIT_SUCCESS;
+		}
+		else
+		{
+			qout << "Unexpected argument: " << arg << endl;
+			usage();
+			return EXIT_FAILURE;
+		}
+	}
+
+	if(logTarget != "null" && logTarget != "syslog")
+	{
+		logTarget = QFileInfo(logTarget).absoluteFilePath();
+		qout << "Writing log to " << logTarget << endl;
+	}
+
 	if(!no_fork)
 	{
 		pid_t pid;
@@ -118,6 +181,9 @@ int main(int argc, char** argv)
 		exit(EXIT_FAILURE);
 	}
 
+	// Install our main object
+	PVSPrivInputHandler handler(sock);
+
 	// set up signal handling:
 	if(socketpair(AF_UNIX, SOCK_DGRAM, 0, signalFds) < 0)
 	{
@@ -135,24 +201,62 @@ int main(int argc, char** argv)
 	signal(SIGTERM, onCaughtSignal);
 	signal(SIGHUP, onCaughtSignal);
 
+	PVSLogRedirector* logRedir = 0;
+	QSocketNotifier* logNotif = 0;
 	// 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);
+		if(logTarget == "null")
+		{
+			freopen("/dev/null", "w", stdout);
+			freopen("/dev/null", "w", stderr);
+		}
+		else if(logTarget == "syslog")
+		{
+			logRedir = new PVSSyslogRedirector();
+		}
+		else
+		{
+			logRedir = new PVSLogfileRedirector(logTarget);
+		}
+
+		if(logRedir)
+		{
+			int logFds[2];
+			if(socketpair(AF_UNIX, SOCK_STREAM, 0, logFds) < 0)
+			{
+				qWarning("Could not open a socket pair: %s", strerror(errno));
+				return EXIT_FAILURE;
+			}
+
+			logNotif = new QSocketNotifier(logFds[1], QSocketNotifier::Read);
+			QObject::connect(logNotif, SIGNAL(activated(int)), logRedir, SLOT(inputAvailableOn(int)));
+
+			// redirect stdout and stderr:
+			dup2(logFds[0], 1);
+			dup2(logFds[0], 2);
+		}
+	}
 
 	atexit(unlinkSocket);
 
+	qout << "PVS Privileged Input Daemon initialization complete. Entering main loop." << endl;
+
 	// and run the main loop.
 	int ret = app.exec();
 
+	if(logRedir)
+	{
+		delete logNotif;
+		delete logRedir;
+	}
 
 	PVSCheckPrivileges::deleteInstance();
+
+	qout << "PVS Privileged Input Daemon deinitialization complete. Exiting." << endl;
+
 	return ret;
 }