Use Linux capabilities to allow us to really use high priority threads

git-svn-id: https://mumble.svn.sourceforge.net/svnroot/mumble/trunk@1587 05730e5d-ab1b-0410-a4ac-84af385074fa

9 files changed, 102 insertions, 22 deletions

diff --git a/src/murmur/DBus.cpp b/src/murmur/DBus.cpp
index 7b32fae67..0f4ded712 100644
--- a/src/murmur/DBus.cpp
+++ b/src/murmur/DBus.cpp
@@ -1016,26 +1016,6 @@ void MetaDBus::setSuperUserPassword(int server_id, const QString &pw, const QDBu
 	}
 }
 
-extern QFile *qfLog;
-
-void MetaDBus::rotateLogs(const QDBusMessage &msg) {
-	if (! qfLog || ! qfLog->isOpen()) {
-		MurmurDBus::qdbc.send(msg.createErrorReply("net.sourceforge.mumble.Error.nolog", "Logfile not in use"));
-		return;
-	}
-	qWarning("Logfile rotation requested from D-Bus, will reopen %s", qPrintable(Meta::mp.qsLogfile));
-	qfLog->close();
-	qfLog->setFileName(Meta::mp.qsLogfile);
-	if (! qfLog->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
-		delete qfLog;
-		qfLog = NULL;
-		MurmurDBus::qdbc.send(msg.createErrorReply("net.sourceforge.mumble.Error.logfail", "Failed to reopen log"));
-	} else {
-		qfLog->setTextModeEnabled(true);
-		qWarning("Log rotated successfully");
-	}
-}
-
 void MetaDBus::quit() {
 	qCritical("Quit requested from D-Bus");
 	QCoreApplication::instance()->quit();
diff --git a/src/murmur/DBus.h b/src/murmur/DBus.h
index 67ad7c202..f06ab6b41 100644
--- a/src/murmur/DBus.h
+++ b/src/murmur/DBus.h
@@ -246,7 +246,6 @@ class MetaDBus : public QDBusAbstractAdaptor {
 		void getDefaultConf(ConfigMap &values);
 		void setConf(int server_id, const QString &key, const QString &value, const QDBusMessage &);
 		void setSuperUserPassword(int server_id, const QString &pw, const QDBusMessage &);
-		void rotateLogs(const QDBusMessage &);
 		void getLog(int server_id, int min_offset, int max_offset, const QDBusMessage &, QList<LogEntry> &entries);
 		void getVersion(int &major, int &minor, int &patch, QString &string);
 		void quit();
diff --git a/src/murmur/Meta.cpp b/src/murmur/Meta.cpp
index c07ffaaf2..14eb66e8d 100644
--- a/src/murmur/Meta.cpp
+++ b/src/murmur/Meta.cpp
@@ -58,6 +58,8 @@ MetaParams::MetaParams() {
 	iBanTries = 10;
 	iBanTimeframe = 120;
 	iBanTime = 300;
+	
+	uiUid = uiGid = 0;
 
 	qrPlayerName = QRegExp(QLatin1String("[-=\\w\\[\\]\\{\\}\\(\\)\\@\\|\\.]+"));
 	qrChannelName = QRegExp(QLatin1String("[ \\-=\\w\\#\\[\\]\\{\\}\\(\\)\\@\\|]+"));
@@ -166,6 +168,20 @@ void MetaParams::read(QString fname) {
 	iBanTries = qs.value("autobanAttempts", iBanTries).toInt();
 	iBanTimeframe = qs.value("autobanTimeframe", iBanTimeframe).toInt();
 	iBanTime = qs.value("autobanTime", iBanTime).toInt();
+	
+#ifdef Q_OS_UNIX
+	const QString uname = qs.value("uname").toString();
+	if (! uname.isEmpty() && (geteuid() == 0)) {
+		struct passwd *pw = getpwnam(qPrintable(uname));
+		if (pw) {
+			uiUid = pw->pw_uid;
+			uiGid = pw->pw_gid;
+		}
+		if (uiUid == 0) {
+			qFatal("Cannot find username %s", qPrintable(uname));
+		}
+	}
+#endif
 
 	qrPlayerName = QRegExp(qs.value("playername", qrPlayerName.pattern()).toString());
 	qrChannelName = QRegExp(qs.value("channelname", qrChannelName.pattern()).toString());
diff --git a/src/murmur/Meta.h b/src/murmur/Meta.h
index 7e3451573..6f3fd2d84 100644
--- a/src/murmur/Meta.h
+++ b/src/murmur/Meta.h
@@ -84,6 +84,8 @@ struct MetaParams {
 	QByteArray qbaPassPhrase;
 
 	QMap<QString, QString> qmConfig;
+	
+	unsigned int uiUid, uiGid;
 
 	MetaParams();
 	void read(QString fname = QString("murmur.ini"));
diff --git a/src/murmur/UnixMurmur.cpp b/src/murmur/UnixMurmur.cpp
index a99b98885..81ef84a2b 100644
--- a/src/murmur/UnixMurmur.cpp
+++ b/src/murmur/UnixMurmur.cpp
@@ -165,7 +165,12 @@ void UnixMurmur::handleSigHup() {
 		qWarning("Caught SIGHUP, will reopen %s", qPrintable(Meta::mp.qsLogfile));
 		qfLog->close();
 		qfLog->setFileName(Meta::mp.qsLogfile);
-		if (! qfLog->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
+		if (Meta::mp.uiUid != 0)
+			setresuid(0,0,0);
+		bool result = qfLog->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text);
+		if (Meta::mp.uiUid != 0)
+			setresuid(Meta::mp.uiUid, Meta::mp.uiUid, 0);
+		if (! result) {
 			delete qfLog;
 			qfLog = NULL;
 		} else {
@@ -187,3 +192,54 @@ void UnixMurmur::handleSigTerm() {
 
 	qsnTerm->setEnabled(true);
 }
+
+void UnixMurmur::setuid() {
+	if (Meta::mp.uiUid != 0) {
+		if (setregid(Meta::mp.uiGid, Meta::mp.uiGid) != 0)
+			qCritical("Failed to switch to gid %d", Meta::mp.uiGid);
+		if (setresuid(Meta::mp.uiUid, Meta::mp.uiUid, 0) != 0) {
+			qFatal("Failed to become uid %d", Meta::mp.uiUid);
+		} else {
+			qCritical("Successfully switched to uid %d", Meta::mp.uiUid);
+		}
+	}
+}
+
+void UnixMurmur::initialcap() {
+#ifdef Q_OS_LINUX
+	cap_value_t caps[] = {CAP_DAC_OVERRIDE, CAP_SYS_NICE, CAP_SETUID };
+
+	if (geteuid() != 0)
+		return;
+		
+	cap_t c = cap_init();
+	cap_clear(c);
+	cap_set_flag(c, CAP_EFFECTIVE, sizeof(caps)/sizeof(cap_value_t), caps, CAP_SET);
+	cap_set_flag(c, CAP_INHERITABLE, sizeof(caps)/sizeof(cap_value_t), caps, CAP_SET);
+	cap_set_flag(c, CAP_PERMITTED, sizeof(caps)/sizeof(cap_value_t), caps, CAP_SET);
+	if (cap_set_proc(c) != 0) {
+		qCritical("Failed to set initial capabilities");
+	} else {
+		qWarning("Successfully dropped initial capabilities");
+	}
+#endif
+}
+
+void UnixMurmur::finalcap() {
+#ifdef Q_OS_LINUX
+	cap_value_t caps[] = {CAP_DAC_OVERRIDE, CAP_SYS_NICE, CAP_SETUID };
+
+	if (Meta::mp.uiUid == 0)
+		return;
+
+	cap_t c = cap_init();
+	cap_clear(c);
+	cap_set_flag(c, CAP_EFFECTIVE, sizeof(caps)/sizeof(cap_value_t), caps, CAP_SET);
+	cap_set_flag(c, CAP_PERMITTED, sizeof(caps)/sizeof(cap_value_t), caps, CAP_SET);
+	if (cap_set_proc(c) != 0) {
+		qCritical("Failed to set final capabilities");
+	} else {
+		qWarning("Successfully dropped capabilities");
+	}
+#endif
+}
diff --git a/src/murmur/UnixMurmur.h b/src/murmur/UnixMurmur.h
index f00ed6216..86b137c01 100644
--- a/src/murmur/UnixMurmur.h
+++ b/src/murmur/UnixMurmur.h
@@ -58,6 +58,10 @@ class UnixMurmur : public QObject {
 		void handleSigHup();

 		void handleSigTerm();

 	public:

+		void setuid();

+		void initialcap();

+		void finalcap();

+

 		UnixMurmur();

 		~UnixMurmur();

 };

diff --git a/src/murmur/main.cpp b/src/murmur/main.cpp
index 9727bb41e..c77e3ad71 100644
--- a/src/murmur/main.cpp
+++ b/src/murmur/main.cpp
@@ -155,6 +155,7 @@ int main(int argc, char **argv) {
 #else
 	QCoreApplication a(argc, argv);
 	UnixMurmur unixhandler;
+	unixhandler.initialcap();
 #endif
 	a.setApplicationName("Murmur");
 	a.setOrganizationName("Mumble");
@@ -256,6 +257,10 @@ int main(int argc, char **argv) {
 	}
 
 	Meta::mp.read(inifile);
+
+#ifdef Q_OS_UNIX
+	unixhandler.setuid();
+#endif
 	ServerDB db;
 
 	meta = new Meta();
@@ -297,6 +302,10 @@ int main(int argc, char **argv) {
 
 	if (detach && ! Meta::mp.qsLogfile.isEmpty()) {
 		qfLog = new QFile(Meta::mp.qsLogfile);
+#ifdef Q_OS_UNIX
+		if (Meta::mp.uiUid != 0)
+			setresuid(Meta::mp.uiUid,0,0);
+#endif
 		if (! qfLog->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
 			delete qfLog;
 			qfLog = NULL;
@@ -311,6 +320,10 @@ int main(int argc, char **argv) {
 			QFileInfo qfi(*qfLog);
 			Meta::mp.qsLogfile = qfi.absoluteFilePath();
 		}
+#ifdef Q_OS_UNIX
+		if (Meta::mp.uiUid != 0)
+			setresuid(Meta::mp.uiUid,Meta::mp.uiUid,0);
+#endif
 	} else {
 		detach = false;
 	}
@@ -351,6 +364,7 @@ int main(int argc, char **argv) {
 		dup2(fd, 2);
 		close(fd);
 	}
+	unixhandler.finalcap();
 #endif
 
 #ifdef USE_DBUS
diff --git a/src/murmur/murmur.pro b/src/murmur/murmur.pro
index 7135dd214..6339e3626 100644
--- a/src/murmur/murmur.pro
+++ b/src/murmur/murmur.pro
@@ -46,6 +46,9 @@ win32 {
 unix {
   UNAME=$$system(uname -s)
   CONFIG *= link_pkgconfig
+  contains(UNAME, Linux) {
+    LIBS *= -lcap
+  }
   
   contains(UNAME, FreeBSD) {
     LIBS *= -lcrypto
diff --git a/src/murmur/murmur_pch.h b/src/murmur/murmur_pch.h
index b83cacd54..06f178d36 100644
--- a/src/murmur/murmur_pch.h
+++ b/src/murmur/murmur_pch.h
@@ -37,6 +37,12 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#ifdef Q_OS_LINUX
+#include <sys/capability.h>
+#endif
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <pwd.h>
 #ifdef __FreeBSD__
 #include <netinet/in_systm.h>
 #endif