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.

4 files changed, 308 insertions, 6 deletions

diff --git a/src/input/CMakeLists.txt b/src/input/CMakeLists.txt
index 0cf5177..a2e6fda 100644
--- a/src/input/CMakeLists.txt
+++ b/src/input/CMakeLists.txt
@@ -18,6 +18,7 @@ if(UNIX)
 		pvsprivinputd.cpp
 		pvsPrivInputHandler.cpp
 		pvsCheckPrivileges.cpp
+		pvsSyslog.cpp
 		pvsPrivInputSignalHandler.cpp
 		rebootSystemHandler.cpp
 		killX11Handler.cpp
@@ -27,6 +28,7 @@ if(UNIX)
 	set(pvsprivinputd_MOC_HDRS
 		pvsPrivInputHandler.h
 		pvsCheckPrivileges.h
+		pvsSyslog.h
 		pvsPrivInputSignalHandler.h
 	)
 
diff --git a/src/input/pvsSyslog.cpp b/src/input/pvsSyslog.cpp
new file mode 100644
index 0000000..6a9be31
--- /dev/null
+++ b/src/input/pvsSyslog.cpp
@@ -0,0 +1,133 @@
+/*
+ # 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/
+ # --------------------------------------------------------------------------
+ # pvsSyslog.cpp:
+ #  - Send output to syslog or to a file - implementation
+ # --------------------------------------------------------------------------
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <cerrno>
+#include <syslog.h>
+#include <QFile>
+#include <QTextStream>
+#include "pvsSyslog.h"
+
+using namespace std;
+
+#define PVS_LOG_BUFSIZ 8192
+
+void PVSLogRedirector::inputAvailableOn(int fd)
+{
+	QByteArray readbuf;
+	readbuf.resize(PVS_LOG_BUFSIZ);
+	ssize_t siz;
+	bool cont = true;
+
+	do
+	{
+		siz = recv(fd, readbuf.data(), readbuf.size(), MSG_DONTWAIT);
+		if(siz > 0)
+		{
+			_buf.append(readbuf.constData(), siz);
+
+			// Send lines:
+			int oldnpos = -1;
+			int npos = -1;
+			while((npos = _buf.indexOf('\n', oldnpos + 1)) >= 0)
+			{
+				if((oldnpos + 1) == npos)
+				{
+					oldnpos = npos;
+					continue;
+				}
+				QString line = QString::fromLocal8Bit(_buf.constData() + oldnpos + 1, npos - oldnpos - 1);
+				doRedirectInput(line);
+				oldnpos = npos;
+			}
+
+			// All complete lines have been sent. Remove sent bytes from buffer.
+			_buf.remove(0, oldnpos + 1);
+
+			// If line length is too large, send it now.
+			if(_buf.size() >= BUFSIZ)
+			{
+				QString longLine = QString::fromLocal8Bit(_buf.constData(), _buf.size());
+				doRedirectInput(longLine);
+				_buf.clear();
+			}
+		}
+		else if(siz == 0)
+		{
+			// Socket closed on other end.
+			break;
+		}
+		else if(siz < 0)
+		{
+			int err = errno;
+			switch(err)
+			{
+			case EAGAIN:
+#if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN)
+			case EWOULDBLOCK:
+#endif
+				// We read all there is to read.
+				cont = false;
+				break;
+			default:
+				// Something happened.
+				// We can't inform the user via qDebug() and friends as that would loop right back to us again,
+				// so we emit a log line.
+				doRedirectInput(QString("Error in logging code: Could not read log input: %s").arg(strerror(err)));
+				cont = false;
+			}
+		}
+	}
+	while(cont);
+}
+
+PVSSyslogRedirector::PVSSyslogRedirector()
+{
+	openlog("pvsprivinputd", LOG_PID, LOG_USER);
+}
+
+PVSSyslogRedirector::~PVSSyslogRedirector()
+{
+	closelog();
+}
+
+void PVSSyslogRedirector::doRedirectInput(QString const& line)
+{
+	QByteArray bytes = line.toLocal8Bit();
+	syslog(LOG_NOTICE, "%s", bytes.data());
+}
+
+PVSLogfileRedirector::PVSLogfileRedirector(QString const& filename)
+{
+	_file = new QFile(filename, this);
+	_file->open(QIODevice::Append);
+	_stream = new QTextStream(_file);
+}
+
+PVSLogfileRedirector::~PVSLogfileRedirector()
+{
+	_stream->flush();
+	_file->close();
+	delete _stream;
+	delete _file;
+}
+
+void PVSLogfileRedirector::doRedirectInput(QString const& line)
+{
+	*_stream << line << flush;
+}
diff --git a/src/input/pvsSyslog.h b/src/input/pvsSyslog.h
new file mode 100644
index 0000000..8c9591a
--- /dev/null
+++ b/src/input/pvsSyslog.h
@@ -0,0 +1,63 @@
+/*
+ # 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/
+ # --------------------------------------------------------------------------
+ # pvsSyslog.h:
+ #  - Send output to syslog or to a file - interface
+ # --------------------------------------------------------------------------
+ */
+
+#ifndef PVSSYSLOG_H_
+#define PVSSYSLOG_H_
+
+#include <QObject>
+#include <QString>
+
+class PVSLogRedirector : public QObject
+{
+	Q_OBJECT
+public slots:
+	void inputAvailableOn(int fd);
+
+protected:
+	virtual void doRedirectInput(QString const& line) = 0;
+
+private:
+	QByteArray _buf;
+};
+
+class PVSSyslogRedirector : public PVSLogRedirector
+{
+public:
+	PVSSyslogRedirector();
+	virtual ~PVSSyslogRedirector();
+
+protected:
+	void doRedirectInput(QString const& line);
+};
+
+class QFile;
+class QTextStream;
+
+class PVSLogfileRedirector : public PVSLogRedirector
+{
+public:
+	PVSLogfileRedirector(QString const& filename);
+	virtual ~PVSLogfileRedirector();
+
+protected:
+	void doRedirectInput(QString const& line);
+
+private:
+	QFile* _file;
+	QTextStream* _stream;
+};
+
+#endif /* PVSSYSLOG_H_ */
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;
 }