// Copyright 2007-2023 The Mumble Developers. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file at the root of the
// Mumble source tree or at <https://www.mumble.info/LICENSE>.

#include "Server.h"

#include "ACL.h"
#include "Channel.h"
#include "ClientType.h"
#include "Connection.h"
#include "EnvUtils.h"
#include "Group.h"
#include "HTMLFilter.h"
#include "HostAddress.h"
#include "Meta.h"
#include "MumbleProtocol.h"
#include "ProtoUtils.h"
#include "QtUtils.h"
#include "ServerDB.h"
#include "ServerUser.h"
#include "User.h"
#include "Version.h"

#ifdef USE_ZEROCONF
#	include "Zeroconf.h"
#endif

#include "Utils.h"

#include <QtCore/QCoreApplication>
#include <QtCore/QSet>
#include <QtCore/QXmlStreamAttributes>
#include <QtCore/QtEndian>
#include <QtNetwork/QHostInfo>
#include <QtNetwork/QSslConfiguration>

#include <boost/bind/bind.hpp>

#include "TracyConstants.h"
#include <tracy/Tracy.hpp>
#include <tracy/TracyC.h>

#include <algorithm>
#include <cassert>
#include <vector>

#ifdef Q_OS_WIN
#	include <qos2.h>
#	include <ws2tcpip.h>
#else
#	include <netinet/in.h>
#	include <poll.h>
#endif

ExecEvent::ExecEvent(boost::function< void() > f) : QEvent(static_cast< QEvent::Type >(EXEC_QEVENT)) {
	func = f;
}

void ExecEvent::execute() {
	func();
}

SslServer::SslServer(QObject *p) : QTcpServer(p) {
}

void SslServer::incomingConnection(qintptr v) {
	QSslSocket *s = new QSslSocket(this);
	s->setSocketDescriptor(v);
	qlSockets.append(s);
}

QSslSocket *SslServer::nextPendingSSLConnection() {
	if (qlSockets.isEmpty())
		return nullptr;
	return qlSockets.takeFirst();
}


Server::Server(int snum, QObject *p) : QThread(p) {
	tracy::SetThreadName("Main");

	bValid     = true;
	iServerNum = snum;
#ifdef USE_ZEROCONF
	zeroconf = nullptr;
#endif
	bUsingMetaCert = false;

#ifdef Q_OS_UNIX
	aiNotify[0] = aiNotify[1] = -1;
#else
	hNotify = nullptr;
#endif
	qtTimeout = new QTimer(this);

	iCodecAlpha = iCodecBeta = 0;
	bPreferAlpha             = false;
	bOpus                    = true;

	qnamNetwork = nullptr;

	readParams();
	initialize();

	foreach (const QHostAddress &qha, qlBind) {
		SslServer *ss = new SslServer(this);

		connect(ss, SIGNAL(newConnection()), this, SLOT(newClient()), Qt::QueuedConnection);

		if (!ss->listen(qha, usPort)) {
			log(QString("Server: TCP Listen on %1 failed: %2").arg(addressToString(qha, usPort), ss->errorString()));
			bValid = false;
		} else {
			log(QString("Server listening on %1").arg(addressToString(qha, usPort)));
		}
		qlServer << ss;
	}

	if (!bValid)
		return;

	foreach (SslServer *ss, qlServer) {
		sockaddr_storage addr;
#ifdef Q_OS_UNIX
		int tcpsock   = static_cast< int >(ss->socketDescriptor());
		socklen_t len = sizeof(addr);
#else
		SOCKET tcpsock        = ss->socketDescriptor();
		int len               = sizeof(addr);
#endif
		memset(&addr, 0, sizeof(addr));
		getsockname(tcpsock, reinterpret_cast< struct sockaddr * >(&addr), &len);
#ifdef Q_OS_UNIX
		int sock = ::socket(addr.ss_family, SOCK_DGRAM, 0);
#	ifdef Q_OS_LINUX
		int sockopt = 1;
		if (setsockopt(sock, IPPROTO_IP, IP_PKTINFO, &sockopt, sizeof(sockopt)))
			log(QString("Failed to set IP_PKTINFO for %1").arg(addressToString(ss->serverAddress(), usPort)));
		sockopt = 1;
		if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &sockopt, sizeof(sockopt)))
			log(QString("Failed to set IPV6_RECVPKTINFO for %1").arg(addressToString(ss->serverAddress(), usPort)));
#	endif
#else
#	ifndef SIO_UDP_CONNRESET
#		define SIO_UDP_CONNRESET _WSAIOW(IOC_VENDOR, 12)
#	endif
		SOCKET sock           = ::WSASocket(addr.ss_family, SOCK_DGRAM, IPPROTO_UDP, nullptr, 0, WSA_FLAG_OVERLAPPED);
		DWORD dwBytesReturned = 0;
		BOOL bNewBehaviour    = FALSE;
		if (WSAIoctl(sock, SIO_UDP_CONNRESET, &bNewBehaviour, sizeof(bNewBehaviour), nullptr, 0, &dwBytesReturned,
					 nullptr, nullptr)
			== SOCKET_ERROR) {
			log(QString("Failed to set SIO_UDP_CONNRESET: %1").arg(WSAGetLastError()));
		}
#endif
		if (sock == INVALID_SOCKET) {
			log("Failed to create UDP Socket");
			bValid = false;
			return;
		} else {
			if (addr.ss_family == AF_INET6) {
				// Copy IPV6_V6ONLY attribute from tcp socket, it defaults to nonzero on Windows
				// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms738574%28v=vs.85%29.aspx
				// This will fail for WindowsXP which is ok. Our TCP code will have split that up
				// into two sockets.
				int ipv6only     = 0;
				socklen_t optlen = sizeof(ipv6only);
				if (::getsockopt(tcpsock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast< char * >(&ipv6only), &optlen)
					== 0) {
					if (::setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast< const char * >(&ipv6only),
									 optlen)
						== SOCKET_ERROR) {
						log(QString("Failed to copy IPV6_V6ONLY socket attribute from tcp to udp socket"));
					}
				}
			}

			if (::bind(sock, reinterpret_cast< sockaddr * >(&addr), len) == SOCKET_ERROR) {
				log(QString("Failed to bind UDP Socket to %1").arg(addressToString(ss->serverAddress(), usPort)));
			} else {
#ifdef Q_OS_UNIX
				int val = 0xe0;
				if (setsockopt(sock, IPPROTO_IP, IP_TOS, &val, sizeof(val))) {
					val = 0x80;
					if (setsockopt(sock, IPPROTO_IP, IP_TOS, &val, sizeof(val)))
						log("Server: Failed to set TOS for UDP Socket");
				}
#	if defined(SO_PRIORITY)
				socklen_t optlen = sizeof(val);
				if (getsockopt(sock, SOL_SOCKET, SO_PRIORITY, &val, &optlen) == 0) {
					if (val == 0) {
						val = 6;
						setsockopt(sock, SOL_SOCKET, SO_PRIORITY, &val, sizeof(val));
					}
				}
#	endif
#endif
			}
			QSocketNotifier *qsn = new QSocketNotifier(sock, QSocketNotifier::Read, this);
			connect(qsn, SIGNAL(activated(int)), this, SLOT(udpActivated(int)));
			qlUdpSocket << sock;
			qlUdpNotifier << qsn;
		}
	}

	bValid = bValid && (qlServer.count() == qlBind.count()) && (qlUdpSocket.count() == qlBind.count());
	if (!bValid)
		return;

#ifdef Q_OS_UNIX
	if (socketpair(AF_UNIX, SOCK_STREAM, 0, aiNotify) != 0) {
		log("Failed to create notify socket");
		bValid = false;
		return;
	}
#else
	hNotify = CreateEvent(nullptr, FALSE, FALSE, nullptr);
#endif

	connect(this, SIGNAL(tcpTransmit(QByteArray, unsigned int)), this, SLOT(tcpTransmitData(QByteArray, unsigned int)),
			Qt::QueuedConnection);
	connect(this, SIGNAL(reqSync(unsigned int)), this, SLOT(doSync(unsigned int)));

	for (int i = 1; i < iMaxUsers * 2; ++i)
		qqIds.enqueue(i);

	connect(qtTimeout, SIGNAL(timeout()), this, SLOT(checkTimeout()));

	getBans();
	readChannels();
	readLinks();
	initializeCert();

	if (bValid) {
#ifdef USE_ZEROCONF
		if (bBonjour)
			initZeroconf();
#endif
		initRegister();
	}
}

void Server::startThread() {
	if (!isRunning()) {
		log("Starting voice thread");
		bRunning = true;

		foreach (QSocketNotifier *qsn, qlUdpNotifier)
			qsn->setEnabled(false);
		start(QThread::HighestPriority);
#ifdef Q_OS_LINUX
		// QThread::HighestPriority == Same as everything else...
		int policy;
		struct sched_param param;
		if (pthread_getschedparam(pthread_self(), &policy, &param) == 0) {
			if (policy == SCHED_OTHER) {
				policy               = SCHED_FIFO;
				param.sched_priority = 1;
				pthread_setschedparam(pthread_self(), policy, &param);
			}
		}
#endif
	}
	if (!qtTimeout->isActive())
		qtTimeout->start(15500);
}

void Server::stopThread() {
	bRunning = false;
	if (isRunning()) {
		log("Ending voice thread");

#ifdef Q_OS_UNIX
		unsigned char val = 0;
		if (::write(aiNotify[1], &val, 1) != 1)
			log("Failed to signal voice thread");
#else
		SetEvent(hNotify);
#endif
		wait();

		foreach (QSocketNotifier *qsn, qlUdpNotifier)
			qsn->setEnabled(true);
	}
	qtTimeout->stop();
}

Server::~Server() {
#ifdef USE_ZEROCONF
	removeZeroconf();
#endif

	stopThread();

	foreach (QSocketNotifier *qsn, qlUdpNotifier)
		delete qsn;

#ifdef Q_OS_UNIX
	foreach (int s, qlUdpSocket)
		close(s);

	if (aiNotify[0] >= 0)
		close(aiNotify[0]);
	if (aiNotify[1] >= 0)
		close(aiNotify[1]);
#else
	foreach (SOCKET s, qlUdpSocket)
		closesocket(s);
	if (hNotify)
		CloseHandle(hNotify);
#endif
	clearACLCache();

	log("Stopped");
}

void Server::readParams() {
	qsPassword                         = Meta::mp.qsPassword;
	usPort                             = static_cast< unsigned short >(Meta::mp.usPort + iServerNum - 1);
	iTimeout                           = Meta::mp.iTimeout;
	iMaxBandwidth                      = Meta::mp.iMaxBandwidth;
	iMaxUsers                          = Meta::mp.iMaxUsers;
	iMaxUsersPerChannel                = Meta::mp.iMaxUsersPerChannel;
	iMaxTextMessageLength              = Meta::mp.iMaxTextMessageLength;
	iMaxImageMessageLength             = Meta::mp.iMaxImageMessageLength;
	bAllowHTML                         = Meta::mp.bAllowHTML;
	iDefaultChan                       = Meta::mp.iDefaultChan;
	bRememberChan                      = Meta::mp.bRememberChan;
	iRememberChanDuration              = Meta::mp.iRememberChanDuration;
	qsWelcomeText                      = Meta::mp.qsWelcomeText;
	qsWelcomeTextFile                  = Meta::mp.qsWelcomeTextFile;
	qlBind                             = Meta::mp.qlBind;
	qsRegName                          = Meta::mp.qsRegName;
	qsRegPassword                      = Meta::mp.qsRegPassword;
	qsRegHost                          = Meta::mp.qsRegHost;
	qsRegLocation                      = Meta::mp.qsRegLocation;
	qurlRegWeb                         = Meta::mp.qurlRegWeb;
	bBonjour                           = Meta::mp.bBonjour;
	bAllowPing                         = Meta::mp.bAllowPing;
	allowRecording                     = Meta::mp.allowRecording;
	bCertRequired                      = Meta::mp.bCertRequired;
	bForceExternalAuth                 = Meta::mp.bForceExternalAuth;
	qrUserName                         = Meta::mp.qrUserName;
	qrChannelName                      = Meta::mp.qrChannelName;
	iMessageLimit                      = Meta::mp.iMessageLimit;
	iMessageBurst                      = Meta::mp.iMessageBurst;
	iPluginMessageLimit                = Meta::mp.iPluginMessageLimit;
	iPluginMessageBurst                = Meta::mp.iPluginMessageBurst;
	broadcastListenerVolumeAdjustments = Meta::mp.broadcastListenerVolumeAdjustments;
	m_suggestVersion                   = Meta::mp.m_suggestVersion;
	qvSuggestPositional                = Meta::mp.qvSuggestPositional;
	qvSuggestPushToTalk                = Meta::mp.qvSuggestPushToTalk;
	iOpusThreshold                     = Meta::mp.iOpusThreshold;
	iChannelNestingLimit               = Meta::mp.iChannelNestingLimit;
	iChannelCountLimit                 = Meta::mp.iChannelCountLimit;

	QString qsHost = getConf("host", QString()).toString();
	if (!qsHost.isEmpty()) {
		qlBind.clear();
#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
		foreach (const QString &host, qsHost.split(QRegExp(QLatin1String("\\s+")), Qt::SkipEmptyParts)) {
#else
		// Qt 5.14 introduced the Qt::SplitBehavior flags deprecating the QString fields
		foreach (const QString &host, qsHost.split(QRegExp(QLatin1String("\\s+")), QString::SkipEmptyParts)) {
#endif
			QHostAddress qhaddr;
			if (qhaddr.setAddress(qsHost)) {
				qlBind << qhaddr;
			} else {
				bool found   = false;
				QHostInfo hi = QHostInfo::fromName(host);
				foreach (QHostAddress qha, hi.addresses()) {
					if ((qha.protocol() == QAbstractSocket::IPv4Protocol)
						|| (qha.protocol() == QAbstractSocket::IPv6Protocol)) {
						qlBind << qha;
						found = true;
					}
				}
				if (!found) {
					log(QString("Lookup of bind hostname %1 failed").arg(host));
				}
			}
		}
		foreach (const QHostAddress &qha, qlBind)
			log(QString("Binding to address %1").arg(qha.toString()));
		if (qlBind.isEmpty())
			qlBind = Meta::mp.qlBind;
	}

	qsPassword             = getConf("password", qsPassword).toString();
	usPort                 = static_cast< unsigned short >(getConf("port", usPort).toUInt());
	iTimeout               = getConf("timeout", iTimeout).toInt();
	iMaxBandwidth          = getConf("bandwidth", iMaxBandwidth).toInt();
	iMaxUsers              = getConf("users", iMaxUsers).toInt();
	iMaxUsersPerChannel    = getConf("usersperchannel", iMaxUsersPerChannel).toInt();
	iMaxTextMessageLength  = getConf("textmessagelength", iMaxTextMessageLength).toInt();
	iMaxImageMessageLength = getConf("imagemessagelength", iMaxImageMessageLength).toInt();
	bAllowHTML             = getConf("allowhtml", bAllowHTML).toBool();
	iDefaultChan           = getConf("defaultchannel", iDefaultChan).toInt();
	bRememberChan          = getConf("rememberchannel", bRememberChan).toBool();
	iRememberChanDuration  = getConf("rememberchannelduration", iRememberChanDuration).toInt();
	qsWelcomeText          = getConf("welcometext", qsWelcomeText).toString();
	qsWelcomeTextFile      = getConf("welcometextfile", qsWelcomeTextFile).toString();

	if (!qsWelcomeTextFile.isEmpty()) {
		if (qsWelcomeText.isEmpty()) {
			QFile f(qsWelcomeTextFile);
			if (f.open(QFile::ReadOnly | QFile::Text)) {
				QTextStream in(&f);
				qsWelcomeText = in.readAll();
				f.close();
			} else {
				log(QString("Failed to open welcome text file %1").arg(qsWelcomeTextFile));
			}
		} else {
			log(QString("Ignoring welcometextfile %1 because welcometext is defined").arg(qsWelcomeTextFile));
		}
	}

	qsRegName          = getConf("registername", qsRegName).toString();
	qsRegPassword      = getConf("registerpassword", qsRegPassword).toString();
	qsRegHost          = getConf("registerhostname", qsRegHost).toString();
	qsRegLocation      = getConf("registerlocation", qsRegLocation).toString();
	qurlRegWeb         = QUrl(getConf("registerurl", qurlRegWeb.toString()).toString());
	bBonjour           = getConf("bonjour", bBonjour).toBool();
	bAllowPing         = getConf("allowping", bAllowPing).toBool();
	bCertRequired      = getConf("certrequired", bCertRequired).toBool();
	bForceExternalAuth = getConf("forceExternalAuth", bForceExternalAuth).toBool();

	m_suggestVersion =
		Version::fromString(getConf("suggestversion", Version::toConfigString(m_suggestVersion)).toString());

	qvSuggestPositional = getConf("suggestpositional", qvSuggestPositional);
	if (qvSuggestPositional.toString().trimmed().isEmpty())
		qvSuggestPositional = QVariant();

	qvSuggestPushToTalk = getConf("suggestpushtotalk", qvSuggestPushToTalk);
	if (qvSuggestPushToTalk.toString().trimmed().isEmpty())
		qvSuggestPushToTalk = QVariant();

	iOpusThreshold = getConf("opusthreshold", iOpusThreshold).toInt();

	iChannelNestingLimit = getConf("channelnestinglimit", iChannelNestingLimit).toInt();
	iChannelCountLimit   = getConf("channelcountlimit", iChannelCountLimit).toInt();

	qrUserName    = QRegExp(getConf("username", qrUserName.pattern()).toString());
	qrChannelName = QRegExp(getConf("channelname", qrChannelName.pattern()).toString());

	iMessageLimit = getConf("messagelimit", iMessageLimit).toUInt();
	if (iMessageLimit < 1) { // Prevent disabling messages entirely
		iMessageLimit = 1;
	}
	iMessageBurst = getConf("messageburst", iMessageBurst).toUInt();
	if (iMessageBurst < 1) { // Prevent disabling messages entirely
		iMessageBurst = 1;
	}

	iPluginMessageLimit = getConf("mpluginessagelimit", iPluginMessageLimit).toUInt();
	if (iPluginMessageLimit < 1) { // Prevent disabling messages entirely
		iPluginMessageLimit = 1;
	}
	iPluginMessageBurst = getConf("pluginmessageburst", iPluginMessageBurst).toUInt();
	if (iPluginMessageBurst < 1) { // Prevent disabling messages entirely
		iPluginMessageBurst = 1;
	}
	broadcastListenerVolumeAdjustments =
		getConf("broadcastlistenervolumeadjustments", broadcastListenerVolumeAdjustments).toBool();
}

void Server::setLiveConf(const QString &key, const QString &value) {
	QString v = value.trimmed().isEmpty() ? QString() : value;
	int i     = v.toInt();
	if ((key == "password") || (key == "serverpassword"))
		qsPassword = !v.isNull() ? v : Meta::mp.qsPassword;
	else if (key == "timeout")
		iTimeout = i ? i : Meta::mp.iTimeout;
	else if (key == "bandwidth") {
		int length = i ? i : Meta::mp.iMaxBandwidth;
		if (length != iMaxBandwidth) {
			iMaxBandwidth = length;
			MumbleProto::ServerConfig mpsc;
			mpsc.set_max_bandwidth(length);
			sendAll(mpsc);
		}
	} else if (key == "users") {
		int newmax = i ? i : Meta::mp.iMaxUsers;
		if (iMaxUsers == newmax)
			return;

		iMaxUsers = newmax;
		qqIds.clear();
		for (int id = 1; id < iMaxUsers * 2; ++id)
			if (!qhUsers.contains(id))
				qqIds.enqueue(id);

		MumbleProto::ServerConfig mpsc;
		mpsc.set_max_users(iMaxUsers);
		sendAll(mpsc);
	} else if (key == "usersperchannel")
		iMaxUsersPerChannel = i ? i : Meta::mp.iMaxUsersPerChannel;
	else if (key == "textmessagelength") {
		int length = i ? i : Meta::mp.iMaxTextMessageLength;
		if (length != iMaxTextMessageLength) {
			iMaxTextMessageLength = length;
			MumbleProto::ServerConfig mpsc;
			mpsc.set_message_length(length);
			sendAll(mpsc);
		}
	} else if (key == "imagemessagelength") {
		int length = i ? i : Meta::mp.iMaxImageMessageLength;
		if (length != iMaxImageMessageLength) {
			iMaxImageMessageLength = length;
			MumbleProto::ServerConfig mpsc;
			mpsc.set_image_message_length(length);
			sendAll(mpsc);
		}
	} else if (key == "allowhtml") {
		bool allow = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bAllowHTML;
		if (allow != bAllowHTML) {
			bAllowHTML = allow;
			MumbleProto::ServerConfig mpsc;
			mpsc.set_allow_html(bAllowHTML);
			sendAll(mpsc);
		}
	} else if (key == "defaultchannel")
		iDefaultChan = i ? i : Meta::mp.iDefaultChan;
	else if (key == "rememberchannel")
		bRememberChan = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bRememberChan;
	else if (key == "rememberchannelduration") {
		iRememberChanDuration = !v.isNull() ? v.toInt() : Meta::mp.iRememberChanDuration;
		if (iRememberChanDuration < 0) {
			iRememberChanDuration = 0;
		}
	} else if (key == "welcometext") {
		QString text = !v.isNull() ? v : Meta::mp.qsWelcomeText;
		if (text != qsWelcomeText) {
			qsWelcomeText = text;
		}
	} else if (key == "registername") {
		QString text = !v.isNull() ? v : Meta::mp.qsRegName;
		if (text != qsRegName) {
			qsRegName = text;
			if (!qsRegName.isEmpty()) {
				MumbleProto::ChannelState mpcs;
				mpcs.set_channel_id(0);
				mpcs.set_name(u8(qsRegName));
				sendAll(mpcs);
			}
		}
	} else if (key == "registerpassword")
		qsRegPassword = !v.isNull() ? v : Meta::mp.qsRegPassword;
	else if (key == "registerhostname")
		qsRegHost = !v.isNull() ? v : Meta::mp.qsRegHost;
	else if (key == "registerlocation")
		qsRegLocation = !v.isNull() ? v : Meta::mp.qsRegLocation;
	else if (key == "registerurl")
		qurlRegWeb = !v.isNull() ? v : Meta::mp.qurlRegWeb;
	else if (key == "certrequired")
		bCertRequired = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bCertRequired;
	else if (key == "forceExternalAuth")
		bForceExternalAuth = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bForceExternalAuth;
	else if (key == "bonjour") {
		bBonjour = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bBonjour;
#ifdef USE_ZEROCONF
		if (bBonjour && !zeroconf) {
			initZeroconf();
		} else if (!bBonjour && zeroconf) {
			removeZeroconf();
		}
#endif
	} else if (key == "allowping")
		bAllowPing = !v.isNull() ? QVariant(v).toBool() : Meta::mp.bAllowPing;
	else if (key == "allowrecording")
		allowRecording = !v.isNull() ? QVariant(v).toBool() : Meta::mp.allowRecording;
	else if (key == "username")
		qrUserName = !v.isNull() ? QRegExp(v) : Meta::mp.qrUserName;
	else if (key == "channelname")
		qrChannelName = !v.isNull() ? QRegExp(v) : Meta::mp.qrChannelName;
	else if (key == "suggestversion")
		m_suggestVersion = !v.isNull() ? Version::fromConfig(v) : Meta::mp.m_suggestVersion;
	else if (key == "suggestpositional")
		qvSuggestPositional = !v.isNull() ? (v.isEmpty() ? QVariant() : v) : Meta::mp.qvSuggestPositional;
	else if (key == "suggestpushtotalk")
		qvSuggestPushToTalk = !v.isNull() ? (v.isEmpty() ? QVariant() : v) : Meta::mp.qvSuggestPushToTalk;
	else if (key == "opusthreshold")
		iOpusThreshold = (i >= 0 && !v.isNull()) ? qBound(0, i, 100) : Meta::mp.iOpusThreshold;
	else if (key == "channelnestinglimit")
		iChannelNestingLimit = (i >= 0 && !v.isNull()) ? i : Meta::mp.iChannelNestingLimit;
	else if (key == "channelcountlimit")
		iChannelCountLimit = (i >= 0 && !v.isNull()) ? i : Meta::mp.iChannelCountLimit;
	else if (key == "messagelimit") {
		iMessageLimit = (!v.isNull()) ? v.toUInt() : Meta::mp.iMessageLimit;
		if (iMessageLimit < 1) {
			iMessageLimit = 1;
		}
	} else if (key == "messageburst") {
		iMessageBurst = (!v.isNull()) ? v.toUInt() : Meta::mp.iMessageBurst;
		if (iMessageBurst < 1) {
			iMessageBurst = 1;
		}
	} else if (key == "broadcastlistenervolumeadjustments") {
		broadcastListenerVolumeAdjustments =
			(!v.isNull() ? QVariant(v).toBool() : Meta::mp.broadcastListenerVolumeAdjustments);
	}
}

#ifdef USE_ZEROCONF
void Server::initZeroconf() {
	zeroconf = new Zeroconf();
	if (zeroconf->isOk()) {
		log("Registering zeroconf service...");
		zeroconf->registerService(BonjourRecord(qsRegName, "_mumble._tcp", ""), usPort);
		return;
	}

	delete zeroconf;
	zeroconf = nullptr;
}

void Server::removeZeroconf() {
	if (!zeroconf) {
		return;
	}

	if (zeroconf->isOk()) {
		log("Unregistering zeroconf service...");
	}

	delete zeroconf;
	zeroconf = nullptr;
}
#endif

gsl::span< const Mumble::Protocol::byte >
	Server::handlePing(const Mumble::Protocol::UDPDecoder< Mumble::Protocol::Role::Server > &decoder,
					   Mumble::Protocol::UDPPingEncoder< Mumble::Protocol::Role::Server > &encoder,
					   bool expectExtended) {
	Mumble::Protocol::PingData pingData = decoder.getPingData();

	if (pingData.requestAdditionalInformation) {
		pingData.requestAdditionalInformation = false;

		pingData.serverVersion                 = Version::get();
		pingData.userCount                     = qhUsers.size() - m_botCount;
		pingData.maxUserCount                  = iMaxUsers;
		pingData.maxBandwidthPerUser           = iMaxBandwidth;
		pingData.containsAdditionalInformation = true;
	} else if (expectExtended) {
		// Return zero-length span
		return {};
	}

	// Encode in the same protocol version that we decoded with
	encoder.setProtocolVersion(decoder.getProtocolVersion());

	return encoder.encodePingPacket(pingData);
}


void Server::customEvent(QEvent *evt) {
	if (evt->type() == EXEC_QEVENT)
		static_cast< ExecEvent * >(evt)->execute();
}

void Server::udpActivated(int socket) {
	// At this part we are only expecting pings of clients we don't know yet -> thus we also don't know which protocol
	// version they are using.
	m_udpDecoder.setProtocolVersion(Version::UNKNOWN);

	qint32 len;

	sockaddr_storage from;
#ifdef Q_OS_UNIX
#	ifdef Q_OS_LINUX
	struct msghdr msg;
	struct iovec iov[1];

	iov[0].iov_base = m_udpDecoder.getBuffer().data();
	iov[0].iov_len  = m_udpDecoder.getBuffer().size();

	uint8_t controldata[CMSG_SPACE(std::max(sizeof(struct in6_pktinfo), sizeof(struct in_pktinfo)))];

	memset(&msg, 0, sizeof(msg));
	msg.msg_name       = reinterpret_cast< struct sockaddr * >(&from);
	msg.msg_namelen    = sizeof(from);
	msg.msg_iov        = iov;
	msg.msg_iovlen     = 1;
	msg.msg_control    = controldata;
	msg.msg_controllen = sizeof(controldata);

	int &sock = socket;
	len       = static_cast< quint32 >(::recvmsg(sock, &msg, MSG_TRUNC));
#	else
	socklen_t fromlen = sizeof(from);
	int &sock         = socket;
	len = static_cast< qint32 >(::recvfrom(sock, m_udpDecoder.getBuffer().data(), m_udpDecoder.getBuffer().size(),
										   MSG_TRUNC, reinterpret_cast< struct sockaddr * >(&from), &fromlen));
#	endif
#else
	int fromlen = sizeof(from);
	SOCKET sock = static_cast< SOCKET >(socket);
	len = ::recvfrom(sock, reinterpret_cast< char * >(m_udpDecoder.getBuffer().data()), m_udpDecoder.getBuffer().size(),
					 0, reinterpret_cast< struct sockaddr * >(&from), &fromlen);
#endif

	gsl::span< Mumble::Protocol::byte > inputData(&m_udpDecoder.getBuffer()[0], len);

	if (bAllowPing && m_udpDecoder.decodePing(inputData)
		&& m_udpDecoder.getMessageType() == Mumble::Protocol::UDPMessageType::Ping) {
		gsl::span< const Mumble::Protocol::byte > encodedPing = handlePing(m_udpDecoder, m_udpPingEncoder, true);

		if (!encodedPing.empty()) {
#ifdef Q_OS_LINUX
			// There will be space for only one header, and the only data we have asked for is the incoming
			// address. So we can reuse most of the same msg and control data.
			iov[0].iov_len  = encodedPing.size();
			iov[0].iov_base = const_cast< Mumble::Protocol::byte * >(encodedPing.data());
			::sendmsg(sock, &msg, 0);
#else
			::sendto(sock, reinterpret_cast< const char * >(encodedPing.data()), encodedPing.size(), 0,
					 reinterpret_cast< struct sockaddr * >(&from), fromlen);
#endif
		}
	}
}

void Server::run() {
	tracy::SetThreadName("Audio");

	qint32 len;
#if defined(__LP64__)
	unsigned char encbuff[Mumble::Protocol::MAX_UDP_PACKET_SIZE + 8];
	unsigned char *encrypt = encbuff + 4;
#else
	unsigned char encrypt[Mumble::Protocol::MAX_UDP_PACKET_SIZE];
#endif
	unsigned char buffer[Mumble::Protocol::MAX_UDP_PACKET_SIZE];

	sockaddr_storage from;
	int nfds = qlUdpSocket.count();

#ifdef Q_OS_UNIX
	socklen_t fromlen;
	STACKVAR(struct pollfd, fds, nfds + 1);

	for (int i = 0; i < nfds; ++i) {
		fds[i].fd      = qlUdpSocket.at(i);
		fds[i].events  = POLLIN;
		fds[i].revents = 0;
	}

	fds[nfds].fd      = aiNotify[0];
	fds[nfds].events  = POLLIN;
	fds[nfds].revents = 0;
#else
	int fromlen;
	STACKVAR(SOCKET, fds, nfds);
	STACKVAR(HANDLE, events, nfds + 1);
	for (int i = 0; i < nfds; ++i) {
		fds[i]    = qlUdpSocket.at(i);
		events[i] = CreateEvent(nullptr, FALSE, FALSE, nullptr);
		::WSAEventSelect(fds[i], events[i], FD_READ);
	}
	events[nfds] = hNotify;
#endif

	++nfds;

	while (bRunning) {
		FrameMarkNamed(TracyConstants::UDP_FRAME);

#ifdef Q_OS_UNIX
		int pret = poll(fds, nfds, -1);
		if (pret <= 0) {
			if (errno == EINTR)
				continue;
			qCritical("poll failure");
			bRunning = false;
			break;
		}

		if (fds[nfds - 1].revents) {
			// Drain pipe
			unsigned char val;
			while (::recv(aiNotify[0], &val, 1, MSG_DONTWAIT) == 1) {
			};
			break;
		}

		for (int i = 0; i < nfds - 1; ++i) {
			if (fds[i].revents) {
				if (fds[i].revents & (POLLHUP | POLLERR | POLLNVAL)) {
					qCritical("poll event failure");
					bRunning = false;
					break;
				}

				int sock = fds[i].fd;
#else
		for (int i = 0; i < 1; ++i) {
			{
				DWORD ret = WaitForMultipleObjects(nfds, events, FALSE, INFINITE);
				if (ret == (WAIT_OBJECT_0 + nfds - 1)) {
					break;
				}
				if (ret == WAIT_FAILED) {
					qCritical("UDP wait failed");
					bRunning = false;
					break;
				}
				SOCKET sock = fds[ret - WAIT_OBJECT_0];
#endif

				fromlen = sizeof(from);
#ifdef Q_OS_WIN
				len = ::recvfrom(sock, reinterpret_cast< char * >(encrypt), Mumble::Protocol::MAX_UDP_PACKET_SIZE, 0,
								 reinterpret_cast< struct sockaddr * >(&from), &fromlen);
#else
#	ifdef Q_OS_LINUX
				struct msghdr msg;
				struct iovec iov[1];

				iov[0].iov_base = encrypt;
				iov[0].iov_len  = Mumble::Protocol::MAX_UDP_PACKET_SIZE;

				uint8_t controldata[CMSG_SPACE(std::max(sizeof(struct in6_pktinfo), sizeof(struct in_pktinfo)))];

				memset(&msg, 0, sizeof(msg));
				msg.msg_name       = reinterpret_cast< struct sockaddr * >(&from);
				msg.msg_namelen    = sizeof(from);
				msg.msg_iov        = iov;
				msg.msg_iovlen     = 1;
				msg.msg_control    = controldata;
				msg.msg_controllen = sizeof(controldata);

				len = static_cast< quint32 >(::recvmsg(sock, &msg, MSG_TRUNC));
				Q_UNUSED(fromlen);
#	else
				len = static_cast< qint32 >(::recvfrom(sock, encrypt, Mumble::Protocol::MAX_UDP_PACKET_SIZE, MSG_TRUNC,
													   reinterpret_cast< struct sockaddr * >(&from), &fromlen));
#	endif
#endif

				// Capture only the processing without the polling
				ZoneScopedN(TracyConstants::UDP_PACKET_PROCESSING_ZONE);

				if (len == 0) {
					break;
				} else if (len == SOCKET_ERROR) {
					break;
				} else if (len < 5) {
					// 4 bytes crypt header + type + session
					continue;
				} else if (static_cast< unsigned int >(len) > Mumble::Protocol::MAX_UDP_PACKET_SIZE) {
					// This will also catch the len == -1 case (indicating error)
					static_assert(static_cast< unsigned int >(-1) > Mumble::Protocol::MAX_UDP_PACKET_SIZE,
								  "Invalid assumption");
					continue;
				}

				QReadLocker rl(&qrwlVoiceThread);

				quint16 port = (from.ss_family == AF_INET6) ? (reinterpret_cast< sockaddr_in6 * >(&from)->sin6_port)
															: (reinterpret_cast< sockaddr_in * >(&from)->sin_port);
				const HostAddress &ha = HostAddress(from);

				const QPair< HostAddress, quint16 > &key = QPair< HostAddress, quint16 >(ha, port);

				ServerUser *u = qhPeerUsers.value(key);

				if (u) {
					m_udpDecoder.setProtocolVersion(u->m_version);
				} else {
					m_udpDecoder.setProtocolVersion(Version::UNKNOWN);
				}
				// This may be a general ping requesting server details, unencrypted.
				if (bAllowPing && m_udpDecoder.decodePing(gsl::span< Mumble::Protocol::byte >(encrypt, len))
					&& m_udpDecoder.getMessageType() == Mumble::Protocol::UDPMessageType::Ping) {
					ZoneScopedN(TracyConstants::PING_PROCESSING_ZONE);

					gsl::span< const Mumble::Protocol::byte > encodedPing =
						handlePing(m_udpDecoder, m_udpPingEncoder, true);

					if (!encodedPing.empty()) {
#ifdef Q_OS_LINUX
						// We are only reading from the buffer and thus the const_cast should be fine
						iov[0].iov_base = const_cast< Mumble::Protocol::byte * >(encodedPing.data());
						iov[0].iov_len  = encodedPing.size();
						::sendmsg(sock, &msg, 0);
#else
						::sendto(sock, reinterpret_cast< const char * >(encodedPing.data()), encodedPing.size(), 0,
								 reinterpret_cast< struct sockaddr * >(&from), fromlen);
#endif
					}

					continue;
				}


				if (u) {
					if (!checkDecrypt(u, encrypt, buffer, len)) {
						continue;
					}
				} else {
					ZoneScopedN(TracyConstants::DECRYPT_UNKNOWN_PEER_ZONE);

					// Unknown peer
					foreach (ServerUser *usr, qhHostUsers.value(ha)) {
						if (checkDecrypt(usr, encrypt, buffer, len)) { // checkDecrypt takes the User's qrwlCrypt lock.
							// Every time we relock, reverify users' existence.
							// The main thread might delete the user while the lock isn't held.
							unsigned int uiSession = usr->uiSession;
							rl.unlock();
							qrwlVoiceThread.lockForWrite();
							if (qhUsers.contains(uiSession)) {
								u             = usr;
								u->sUdpSocket = sock;
								memcpy(&u->saiUdpAddress, &from, sizeof(from));
								qhHostUsers[from].remove(u);
								qhPeerUsers.insert(key, u);
							}
							qrwlVoiceThread.unlock();
							rl.relock();
							if (u && !qhUsers.contains(uiSession))
								u = nullptr;
							break;
						}
					}
					if (!u) {
						continue;
					}
				}
				len -= 4;

				if (m_udpDecoder.decode(gsl::span< Mumble::Protocol::byte >(buffer, len))) {
					switch (m_udpDecoder.getMessageType()) {
						case Mumble::Protocol::UDPMessageType::Audio: {
							Mumble::Protocol::AudioData audioData = m_udpDecoder.getAudioData();

							// Allow all voice packets through by default.
							bool ok = true;
							// ...Unless we're in Opus mode. In Opus mode, only Opus packets are allowed.
							if (bOpus && audioData.usedCodec != Mumble::Protocol::AudioCodec::Opus) {
								ok = false;
							}

							if (ok) {
								u->aiUdpFlag = 1;

								// Add session id
								audioData.senderSession = u->uiSession;

								processMsg(u, audioData, m_udpAudioReceivers, m_udpAudioEncoder);
							}
							break;
						}
						case Mumble::Protocol::UDPMessageType::Ping: {
							ZoneScopedN(TracyConstants::UDP_PING_PROCESSING_ZONE);

							Mumble::Protocol::PingData pingData = m_udpDecoder.getPingData();
							if (!pingData.requestAdditionalInformation && !pingData.containsAdditionalInformation) {
								// At this point here, we only want to handle connectivity pings
								gsl::span< const Mumble::Protocol::byte > encodedPing =
									handlePing(m_udpDecoder, m_udpPingEncoder, false);

								QByteArray cache;
								sendMessage(*u, encodedPing.data(), encodedPing.size(), cache, true);
							}
							break;
						}
					}
				}
#ifdef Q_OS_UNIX
				fds[i].revents = 0;
#endif
			}
		}
	}
#ifdef Q_OS_WIN
	for (int i = 0; i < nfds - 1; ++i) {
		::WSAEventSelect(fds[i], nullptr, 0);
		CloseHandle(events[i]);
	}
#endif
}

bool Server::checkDecrypt(ServerUser *u, const unsigned char *encrypt, unsigned char *plain, unsigned int len) {
	ZoneScoped;

	QMutexLocker l(&u->qmCrypt);

	if (u->csCrypt->isValid() && u->csCrypt->decrypt(encrypt, plain, len)) {
		return true;
	}

	if (u->csCrypt->tLastGood.elapsed() > 5000000ULL) {
		if (u->csCrypt->tLastRequest.elapsed() > 5000000ULL) {
			u->csCrypt->tLastRequest.restart();
			emit reqSync(u->uiSession);
		}
	}
	return false;
}

void Server::sendMessage(ServerUser &u, const unsigned char *data, int len, QByteArray &cache, bool force) {
	ZoneScoped;

#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
	if ((u.aiUdpFlag.loadRelaxed() == 1 || force) && (u.sUdpSocket != INVALID_SOCKET)) {
#else
	// Qt 5.14 introduced QAtomicInteger::loadRelaxed() which deprecates QAtomicInteger::load()
	if ((u.aiUdpFlag.load() == 1 || force) && (u.sUdpSocket != INVALID_SOCKET)) {
#endif
#if defined(__LP64__)
		STACKVAR(char, ebuffer, len + 4 + 16);
		char *buffer = reinterpret_cast< char * >(((reinterpret_cast< quint64 >(ebuffer) + 8) & ~7) + 4);
#else
		STACKVAR(char, buffer, len + 4);
#endif
		{
			QMutexLocker wl(&u.qmCrypt);

			if (!u.csCrypt->isValid()) {
				return;
			}

			if (!u.csCrypt->encrypt(reinterpret_cast< const unsigned char * >(data),
									reinterpret_cast< unsigned char * >(buffer), len)) {
				return;
			}
		}
#ifdef Q_OS_WIN
		DWORD dwFlow = 0;
		if (Meta::hQoS)
			QOSAddSocketToFlow(Meta::hQoS, u.sUdpSocket, reinterpret_cast< struct sockaddr * >(&u.saiUdpAddress),
							   QOSTrafficTypeVoice, QOS_NON_ADAPTIVE_FLOW, reinterpret_cast< PQOS_FLOWID >(&dwFlow));
#endif
#ifdef Q_OS_LINUX
		struct msghdr msg;
		struct iovec iov[1];

		iov[0].iov_base = buffer;
		iov[0].iov_len  = len + 4;

		uint8_t controldata[CMSG_SPACE(std::max(sizeof(struct in6_pktinfo), sizeof(struct in_pktinfo)))];
		memset(controldata, 0, sizeof(controldata));

		memset(&msg, 0, sizeof(msg));
		msg.msg_name    = reinterpret_cast< struct sockaddr * >(&u.saiUdpAddress);
		msg.msg_namelen = static_cast< socklen_t >(
			(u.saiUdpAddress.ss_family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in));
		msg.msg_iov        = iov;
		msg.msg_iovlen     = 1;
		msg.msg_control    = controldata;
		msg.msg_controllen = CMSG_SPACE((u.saiUdpAddress.ss_family == AF_INET6) ? sizeof(struct in6_pktinfo)
																				: sizeof(struct in_pktinfo));

		struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
		HostAddress tcpha(u.saiTcpLocalAddress);
		if (u.saiUdpAddress.ss_family == AF_INET6) {
			cmsg->cmsg_level            = IPPROTO_IPV6;
			cmsg->cmsg_type             = IPV6_PKTINFO;
			cmsg->cmsg_len              = CMSG_LEN(sizeof(struct in6_pktinfo));
			struct in6_pktinfo *pktinfo = reinterpret_cast< struct in6_pktinfo * >(CMSG_DATA(cmsg));
			memset(pktinfo, 0, sizeof(*pktinfo));
			memcpy(&pktinfo->ipi6_addr.s6_addr[0], &tcpha.qip6.c[0], sizeof(pktinfo->ipi6_addr.s6_addr));
		} else {
			cmsg->cmsg_level           = IPPROTO_IP;
			cmsg->cmsg_type            = IP_PKTINFO;
			cmsg->cmsg_len             = CMSG_LEN(sizeof(struct in_pktinfo));
			struct in_pktinfo *pktinfo = reinterpret_cast< struct in_pktinfo * >(CMSG_DATA(cmsg));
			memset(pktinfo, 0, sizeof(*pktinfo));
			if (tcpha.isV6())
				return;
			pktinfo->ipi_spec_dst.s_addr = tcpha.hash[3];
		}


		::sendmsg(u.sUdpSocket, &msg, 0);
#else
		::sendto(u.sUdpSocket, buffer, len + 4, 0, reinterpret_cast< struct sockaddr * >(&u.saiUdpAddress),
				 (u.saiUdpAddress.ss_family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in));
#endif
#ifdef Q_OS_WIN
		if (Meta::hQoS && dwFlow)
			QOSRemoveSocketFromFlow(Meta::hQoS, 0, dwFlow, 0);
#else
#endif
	} else {
		if (cache.isEmpty())
			cache = QByteArray(reinterpret_cast< const char * >(data), len);
		emit tcpTransmit(cache, u.uiSession);
	}
}

void Server::addListener(QHash< ServerUser *, VolumeAdjustment > &listeners, ServerUser &user, const Channel &channel) {
	const VolumeAdjustment &volumeAdjustment =
		m_channelListenerManager.getListenerVolumeAdjustment(user.uiSession, channel.iId);

	auto it = listeners.find(&user);

	if (it == listeners.end() || it->factor < volumeAdjustment.factor) {
		listeners[&user] = volumeAdjustment;
	}
}

void Server::processMsg(ServerUser *u, Mumble::Protocol::AudioData audioData, AudioReceiverBuffer &buffer,
						Mumble::Protocol::UDPAudioEncoder< Mumble::Protocol::Role::Server > &encoder) {
	ZoneScoped;

	// Note that in this function we never have to acquire a read-lock on qrwlVoiceThread
	// as all places that call this function will hold that lock at the point of calling
	// this function.
	// This function is currently called from Server::msgUDPTunnel, Server::run and
	// Server::message
	if (u->sState != ServerUser::Authenticated || u->bMute || u->bSuppress || u->bSelfMute)
		return;

	// Check the voice data rate limit.
	{
		BandwidthRecord *bw = &u->bwr;

		// IP + UDP + Crypt + Data
		const int packetsize = 20 + 8 + 4 + audioData.payload.size();

		if (!bw->addFrame(packetsize, iMaxBandwidth / 8)) {
			// Suppress packet.
			return;
		}
	}

	buffer.clear();

	if (audioData.targetOrContext == Mumble::Protocol::ReservedTargetIDs::SERVER_LOOPBACK) {
		buffer.forceAddReceiver(*u, Mumble::Protocol::AudioContext::NORMAL, audioData.containsPositionalData);
	} else if (audioData.targetOrContext == Mumble::Protocol::ReservedTargetIDs::REGULAR_SPEECH) {
		Channel *c = u->cChannel;

		// Send audio to all users that are listening to the channel
		foreach (unsigned int currentSession, m_channelListenerManager.getListenersForChannel(c->iId)) {
			ServerUser *pDst = static_cast< ServerUser * >(qhUsers.value(currentSession));
			if (pDst) {
				buffer.addReceiver(*u, *pDst, Mumble::Protocol::AudioContext::LISTEN, audioData.containsPositionalData,
								   m_channelListenerManager.getListenerVolumeAdjustment(pDst->uiSession, c->iId));
			}
		}

		// Send audio to all users in the same channel
		for (User *p : c->qlUsers) {
			ServerUser *pDst = static_cast< ServerUser * >(p);

			buffer.addReceiver(*u, *pDst, Mumble::Protocol::AudioContext::NORMAL, audioData.containsPositionalData);
		}

		// Send audio to all linked channels the user has speak-permission
		if (!c->qhLinks.isEmpty()) {
			QSet< Channel * > chans = c->allLinks();
			chans.remove(c);

			QMutexLocker qml(&qmCache);

			for (Channel *l : chans) {
				if (ChanACL::hasPermission(u, l, ChanACL::Speak, &acCache)) {
					// Send the audio stream to all users that are listening to the linked channel
					for (unsigned int currentSession : m_channelListenerManager.getListenersForChannel(l->iId)) {
						ServerUser *pDst = static_cast< ServerUser * >(qhUsers.value(currentSession));
						if (pDst) {
							buffer.addReceiver(
								*u, *pDst, Mumble::Protocol::AudioContext::LISTEN, audioData.containsPositionalData,
								m_channelListenerManager.getListenerVolumeAdjustment(pDst->uiSession, l->iId));
						}
					}

					// Send audio to users in the linked channel
					for (User *p : l->qlUsers) {
						ServerUser *pDst = static_cast< ServerUser * >(p);

						buffer.addReceiver(*u, *pDst, Mumble::Protocol::AudioContext::NORMAL,
										   audioData.containsPositionalData);
					}
				}
			}
		}
	} else if (u->qmTargets.contains(audioData.targetOrContext)) { // Whisper/Shout
		QSet< ServerUser * > channel;
		QSet< ServerUser * > direct;
		QHash< ServerUser *, VolumeAdjustment > cachedListeners;

		if (u->qmTargetCache.contains(audioData.targetOrContext)) {
			ZoneScopedN(TracyConstants::AUDIO_WHISPER_CACHE_STORE);

			const WhisperTargetCache &cache = u->qmTargetCache.value(audioData.targetOrContext);
			channel                         = cache.channelTargets;
			direct                          = cache.directTargets;
			cachedListeners                 = cache.listeningTargets;
		} else {
			ZoneScopedN(TracyConstants::AUDIO_WHISPER_CACHE_CREATE);

			const WhisperTarget &wt = u->qmTargets.value(audioData.targetOrContext);
			if (!wt.qlChannels.isEmpty()) {
				QMutexLocker qml(&qmCache);

				foreach (const WhisperTarget::Channel &wtc, wt.qlChannels) {
					Channel *wc = qhChannels.value(wtc.iId);
					if (wc) {
						bool link       = wtc.bLinks && !wc->qhLinks.isEmpty();
						bool dochildren = wtc.bChildren && !wc->qlChannels.isEmpty();
						bool group      = !wtc.qsGroup.isEmpty();
						if (!link && !dochildren && !group) {
							// Common case
							if (ChanACL::hasPermission(u, wc, ChanACL::Whisper, &acCache)) {
								foreach (User *p, wc->qlUsers) { channel.insert(static_cast< ServerUser * >(p)); }

								foreach (unsigned int currentSession,
										 m_channelListenerManager.getListenersForChannel(wc->iId)) {
									ServerUser *pDst = static_cast< ServerUser * >(qhUsers.value(currentSession));

									if (pDst) {
										addListener(cachedListeners, *pDst, *wc);
									}
								}
							}
						} else {
							QSet< Channel * > channels;
							if (link)
								channels = wc->allLinks();
							else
								channels.insert(wc);
							if (dochildren)
								channels.unite(wc->allChildren());
							const QString &redirect = u->qmWhisperRedirect.value(wtc.qsGroup);
							const QString &qsg      = redirect.isEmpty() ? wtc.qsGroup : redirect;
							foreach (Channel *tc, channels) {
								if (ChanACL::hasPermission(u, tc, ChanACL::Whisper, &acCache)) {
									foreach (User *p, tc->qlUsers) {
										ServerUser *su = static_cast< ServerUser * >(p);

										if (!group || Group::appliesToUser(*tc, *tc, qsg, *su)) {
											channel.insert(su);
										}
									}

									foreach (unsigned int currentSession,
											 m_channelListenerManager.getListenersForChannel(tc->iId)) {
										ServerUser *pDst = static_cast< ServerUser * >(qhUsers.value(currentSession));

										if (pDst && (!group || Group::appliesToUser(*tc, *tc, qsg, *pDst))) {
											// Only send audio to listener if the user exists and it is in the group the
											// speech is directed at (if any)
											addListener(cachedListeners, *pDst, *tc);
										}
									}
								}
							}
						}
					}
				}
			}

			{
				QMutexLocker qml(&qmCache);

				foreach (unsigned int id, wt.qlSessions) {
					ServerUser *pDst = qhUsers.value(id);
					if (pDst && ChanACL::hasPermission(u, pDst->cChannel, ChanACL::Whisper, &acCache)
						&& !channel.contains(pDst))
						direct.insert(pDst);
				}
			}

			int uiSession = u->uiSession;
			qrwlVoiceThread.unlock();
			qrwlVoiceThread.lockForWrite();

			if (qhUsers.contains(uiSession))
				u->qmTargetCache.insert(audioData.targetOrContext, { channel, direct, cachedListeners });
			qrwlVoiceThread.unlock();
			qrwlVoiceThread.lockForRead();
			if (!qhUsers.contains(uiSession))
				return;
		}
		// These users receive the audio because someone is shouting to their channel
		for (ServerUser *pDst : channel) {
			buffer.addReceiver(*u, *pDst, Mumble::Protocol::AudioContext::SHOUT, audioData.containsPositionalData);
		}
		// These users receive audio because someone is whispering to them
		for (ServerUser *pDst : direct) {
			buffer.addReceiver(*u, *pDst, Mumble::Protocol::AudioContext::WHISPER, audioData.containsPositionalData);
		}
		// These users receive audio because someone is sending audio to one of their listeners
		QHashIterator< ServerUser *, VolumeAdjustment > it(cachedListeners);
		while (it.hasNext()) {
			it.next();
			ServerUser *user                         = it.key();
			const VolumeAdjustment &volumeAdjustment = it.value();

			buffer.addReceiver(*u, *user, Mumble::Protocol::AudioContext::LISTEN, audioData.containsPositionalData,
							   volumeAdjustment);
		}
	}

	ZoneNamedN(__tracy_scoped_zone2, TracyConstants::AUDIO_SENDOUT_ZONE, true);

	buffer.preprocessBuffer();

	bool isFirstIteration = true;
	QByteArray tcpCache;
	for (bool includePositionalData : { true, false }) {
		std::vector< AudioReceiver > &receiverList = buffer.getReceivers(includePositionalData);

		audioData.containsPositionalData = includePositionalData && audioData.containsPositionalData;

		if (!audioData.containsPositionalData) {
			encoder.dropPositionalData();
		}

		// Note: The receiver-ranges are determined in such a way, that they are all going to receive the exact
		// same audio packet.
		ReceiverRange< std::vector< AudioReceiver >::iterator > currentRange =
			AudioReceiverBuffer::getReceiverRange(receiverList.begin(), receiverList.end());

		while (currentRange.begin != currentRange.end) {
			// Setup encoder for this range
			if (isFirstIteration
				|| !Mumble::Protocol::protocolVersionsAreCompatible(encoder.getProtocolVersion(),
																	currentRange.begin->getReceiver().m_version)) {
				ZoneScopedN(TracyConstants::AUDIO_ENCODE);

				encoder.setProtocolVersion(currentRange.begin->getReceiver().m_version);

				// We have to re-encode the "fixed" part of the audio message
				encoder.prepareAudioPacket(audioData);

				if (audioData.containsPositionalData) {
					encoder.addPositionalData(audioData);
				}

				isFirstIteration = false;
			}

			audioData.targetOrContext  = currentRange.begin->getContext();
			audioData.volumeAdjustment = currentRange.begin->getVolumeAdjustment();

			// Update data
			TracyCZoneN(__tracy_zone, TracyConstants::AUDIO_UPDATE, true);
			gsl::span< const Mumble::Protocol::byte > encodedPacket = encoder.updateAudioPacket(audioData);
			TracyCZoneEnd(__tracy_zone);

			// Clear TCP cache
			tcpCache.clear();

			// Send encoded packet to all receivers of this range
			for (auto it = currentRange.begin; it != currentRange.end; ++it) {
				sendMessage(it->getReceiver(), encodedPacket.data(), encodedPacket.size(), tcpCache);
			}

			// Find next range
			currentRange = AudioReceiverBuffer::getReceiverRange(currentRange.end, receiverList.end());
		}
	}
}

void Server::log(ServerUser *u, const QString &str) const {
	QString msg = QString("<%1:%2(%3)> %4").arg(QString::number(u->uiSession), u->qsName, QString::number(u->iId), str);
	log(msg);
}

void Server::log(const QString &msg) const {
	dblog(msg);
	qWarning("%d => %s", iServerNum, msg.toUtf8().constData());
}

void Server::newClient() {
	SslServer *ss = qobject_cast< SslServer * >(sender());
	if (!ss)
		return;
	forever {
		QSslSocket *sock = ss->nextPendingSSLConnection();
		if (!sock)
			return;

		QHostAddress adr = sock->peerAddress();

		if (meta->banCheck(adr)) {
			log(QString("Ignoring connection: %1 (Global ban)")
					.arg(addressToString(sock->peerAddress(), sock->peerPort())));
			sock->disconnectFromHost();
			sock->deleteLater();
			return;
		}

		HostAddress ha(adr);

		QList< Ban > tmpBans = qlBans;
		foreach (const Ban &ban, qlBans) {
			if (ban.isExpired())
				tmpBans.removeOne(ban);
		}
		if (qlBans.count() != tmpBans.count()) {
			qlBans = tmpBans;
			saveBans();
		}

		foreach (const Ban &ban, qlBans) {
			if (ban.haAddress.match(ha, ban.iMask)) {
				log(QString("Ignoring connection: %1, Reason: %2, Username: %3, Hash: %4 (Server ban)")
						.arg(addressToString(sock->peerAddress(), sock->peerPort()), ban.qsReason, ban.qsUsername,
							 ban.qsHash));
				sock->disconnectFromHost();
				sock->deleteLater();
				return;
			}
		}

#ifdef Q_OS_MAC
		// One unexpected behavior of Qt's SSL backend is: it will add the key pair
		// it uses in a connection into the default keychain, and when access the private
		// key afterwards, a pop up will show up asking for user's permission.
		// In some case (OS X 10.15.5), this pop up will be suppressed somehow and no private
		// key is returned.
		// This env variable will avoid Qt directly adding the key pair into the default keychain,
		// using a temporary keychain instead.
		// See #4298 and https://codereview.qt-project.org/c/qt/qtbase/+/184243
		EnvUtils::setenv("QT_SSL_USE_TEMPORARY_KEYCHAIN", "1");
#endif
		sock->setPrivateKey(qskKey);
		sock->setLocalCertificate(qscCert);

		QSslConfiguration config;
#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
		config = sock->sslConfiguration();
		// Qt 5.15 introduced QSslConfiguration::addCaCertificate(s) that should be preferred over the functions in
		// QSslSocket

		// Treat the leaf certificate as a root.
		// This shouldn't strictly be necessary,
		// and is a left-over from early on.
		// Perhaps it is necessary for self-signed
		// certs?
		config.addCaCertificate(qscCert);

		// Add CA certificates specified via
		// murmur.ini's sslCA option.
		config.addCaCertificates(Meta::mp.qlCA);

		// Add intermediate CAs found in the PEM
		// bundle used for this server's certificate.
		config.addCaCertificates(qlIntermediates);
#else
		// Treat the leaf certificate as a root.
		// This shouldn't strictly be necessary,
		// and is a left-over from early on.
		// Perhaps it is necessary for self-signed
		// certs?
		sock->addCaCertificate(qscCert);

		// Add CA certificates specified via
		// murmur.ini's sslCA option.
		sock->addCaCertificates(Meta::mp.qlCA);

		// Add intermediate CAs found in the PEM
		// bundle used for this server's certificate.
		sock->addCaCertificates(qlIntermediates);

		// Must not get config from socket before setting CA certificates
		config = sock->sslConfiguration();
#endif

		config.setCiphers(Meta::mp.qlCiphers);
#if defined(USE_QSSLDIFFIEHELLMANPARAMETERS)
		config.setDiffieHellmanParameters(qsdhpDHParams);
#endif
		sock->setSslConfiguration(config);

		if (qqIds.isEmpty()) {
			log(QString("Session ID pool (%1) empty, rejecting connection").arg(iMaxUsers));
			sock->disconnectFromHost();
			sock->deleteLater();
			return;
		}

		ServerUser *u = new ServerUser(this, sock);
		u->haAddress  = ha;
		HostAddress(sock->localAddress()).toSockaddr(&u->saiTcpLocalAddress);

		connect(u, &ServerUser::connectionClosed, this, &Server::connectionClosed);
		connect(u, SIGNAL(message(Mumble::Protocol::TCPMessageType, const QByteArray &)), this,
				SLOT(message(Mumble::Protocol::TCPMessageType, const QByteArray &)));
		connect(u, &ServerUser::handleSslErrors, this, &Server::sslError);
		connect(u, &ServerUser::encrypted, this, &Server::encrypted);

		log(u, QString("New connection: %1").arg(addressToString(sock->peerAddress(), sock->peerPort())));

		u->setToS();

#if QT_VERSION >= 0x050500
		sock->setProtocol(QSsl::TlsV1_0OrLater);
#elif QT_VERSION >= 0x050400
		// In Qt 5.4, QSsl::SecureProtocols is equivalent
		// to "TLSv1.0 or later", which we require.
		sock->setProtocol(QSsl::SecureProtocols);
#else
		sock->setProtocol(QSsl::TlsV1_0);
#endif
		sock->startServerEncryption();

		meta->successfulConnectionFrom(adr);
	}
}

void Server::encrypted() {
	ServerUser *uSource = qobject_cast< ServerUser * >(sender());

	MumbleProto::Version mpv;
	MumbleProto::setVersion(mpv, Version::get());
	if (Meta::mp.bSendVersion) {
		mpv.set_release(u8(Version::getRelease()));
		mpv.set_os(u8(meta->qsOS));
		mpv.set_os_version(u8(meta->qsOSVersion));
	}
	sendMessage(uSource, mpv);

	QList< QSslCertificate > certs = uSource->peerCertificateChain();
	if (!certs.isEmpty()) {
		// Get the client's immediate SSL certificate
		const QSslCertificate &cert = certs.first();
		uSource->qslEmail           = cert.subjectAlternativeNames().values(QSsl::EmailEntry);
		uSource->qsHash             = QString::fromLatin1(cert.digest(QCryptographicHash::Sha1).toHex());
		if (!uSource->qslEmail.isEmpty() && uSource->bVerified) {
			QString subject;
			QString issuer;

			QStringList subjectList = cert.subjectInfo(QSslCertificate::CommonName);
			if (!subjectList.isEmpty()) {
				subject = subjectList.first();
			}

			QStringList issuerList = certs.first().issuerInfo(QSslCertificate::CommonName);
			if (!issuerList.isEmpty()) {
				issuer = issuerList.first();
			}

			log(uSource, QString::fromUtf8("Strong certificate for %1 <%2> (signed by %3)")
							 .arg(subject)
							 .arg(uSource->qslEmail.join(", "))
							 .arg(issuer));
		}

		foreach (const Ban &ban, qlBans) {
			if (ban.qsHash == uSource->qsHash) {
				log(uSource, QString("Certificate hash is banned: %1, Username: %2, Reason: %3.")
								 .arg(ban.qsHash, ban.qsUsername, ban.qsReason));
				uSource->disconnectSocket();
			}
		}
	}
}

void Server::sslError(const QList< QSslError > &errors) {
	ServerUser *u = qobject_cast< ServerUser * >(sender());
	if (!u)
		return;

	bool ok = true;
	foreach (QSslError e, errors) {
		switch (e.error()) {
			case QSslError::InvalidPurpose:
				// Allow email certificates.
				break;
			case QSslError::NoPeerCertificate:
			case QSslError::SelfSignedCertificate:
			case QSslError::SelfSignedCertificateInChain:
			case QSslError::UnableToGetLocalIssuerCertificate:
			case QSslError::UnableToVerifyFirstCertificate:
			case QSslError::HostNameMismatch:
			case QSslError::CertificateNotYetValid:
			case QSslError::CertificateExpired:
				u->bVerified = false;
				break;
			default:
				log(u, QString("SSL Error: %1").arg(e.errorString()));
				ok = false;
		}
	}

	if (ok) {
		u->proceedAnyway();
	} else {
		// Due to a regression in Qt 5 (QTBUG-53906),
		// we can't 'force' disconnect (which calls
		// QAbstractSocket->abort()) when built against Qt 5.
		//
		// The bug is that Qt doesn't update the
		// QSslSocket's socket state when QSslSocket->abort()
		// is called.
		//
		// Our call to abort() happens when QSslSocket is inside
		// startHandshake(). That is, a handshake is in progress.
		//
		// After emitting the peerVerifyError/sslErrors signals,
		// startHandshake() checks whether the connection is still
		// in QAbstractSocket::ConectedState.
		//
		// Unfortunately, because abort() doesn't update the socket's
		// state to signal that it is no longer connected, startHandshake()
		// still thinks the socket is connected and will continue to
		// attempt to finish the handshake.
		//
		// Because abort() tears down a lot of internal state
		// of the QSslSocket, including the 'SSL *' object
		// associated with the socket, this is fatal and leads
		// to crashes, such as attempting to derefernce a nullptr
		// 'SSL *' object.
		//
		// To avoid this, we use a non-forceful disconnect
		// until this is fixed upstream.
		//
		// See
		// https://bugreports.qt.io/browse/QTBUG-53906
		// https://github.com/mumble-voip/mumble/issues/2334

		u->disconnectSocket();
	}
}

void Server::connectionClosed(QAbstractSocket::SocketError err, const QString &reason) {
	if (reason.contains(QLatin1String("140E0197"))) {
		// A severe bug was introduced in qt/qtbase@93a803a6de27d9eb57931c431b5f3d074914f693.
		// q_SSL_shutdown() causes Qt to emit "error()" from unrelated QSslSocket(s), in addition to the correct
		// one. The issue causes this function to disconnect random authenticated clients.
		//
		// The workaround consists in ignoring a specific OpenSSL error:
		// "Error while reading: error:140E0197:SSL routines:SSL_shutdown:shutdown while in init [20]"
		//
		// Definitely not ideal, but it fixes a critical vulnerability.
		qWarning("Ignored OpenSSL error 140E0197 for %p", static_cast< void * >(sender()));
		return;
	}

	Connection *c = qobject_cast< Connection * >(sender());
	if (!c)
		return;
	if (c->bDisconnectedEmitted)
		return;
	c->bDisconnectedEmitted = true;

	ServerUser *u = static_cast< ServerUser * >(c);

	log(u, QString("Connection closed: %1 [%2]").arg(reason).arg(err));

	setLastDisconnect(u);

	if (u->sState == ServerUser::Authenticated) {
		if (m_channelListenerManager.isListeningToAny(u->uiSession)) {
			foreach (int channelID, m_channelListenerManager.getListenedChannelsForUser(u->uiSession)) {
				// Remove the client from the list on the server
				m_channelListenerManager.removeListener(u->uiSession, channelID);
			}
		}

		MumbleProto::UserRemove mpur;
		mpur.set_session(u->uiSession);
		sendExcept(u, mpur);

		if (u->m_clientType == ClientType::BOT) {
			m_botCount--;
		}

		emit userDisconnected(u);
	}

	Channel *old = u->cChannel;

	{
		QWriteLocker wl(&qrwlVoiceThread);

		qhUsers.remove(u->uiSession);
		qhHostUsers[u->haAddress].remove(u);

		quint16 port = (u->saiUdpAddress.ss_family == AF_INET6)
						   ? (reinterpret_cast< sockaddr_in6 * >(&u->saiUdpAddress)->sin6_port)
						   : (reinterpret_cast< sockaddr_in * >(&u->saiUdpAddress)->sin_port);
		const QPair< HostAddress, quint16 > &key = QPair< HostAddress, quint16 >(u->haAddress, port);
		qhPeerUsers.remove(key);

		if (old)
			old->removeUser(u);
	}

	if (old && old->bTemporary && old->qlUsers.isEmpty())
		QCoreApplication::instance()->postEvent(this,
												new ExecEvent(boost::bind(&Server::removeChannel, this, old->iId)));

	if (u->uiSession > 0 && static_cast< int >(u->uiSession) < iMaxUsers * 2)
		qqIds.enqueue(u->uiSession); // Reinsert session id into pool

	if (u->sState == ServerUser::Authenticated) {
		clearTempGroups(u);     // Also clears ACL cache
		recheckCodecVersions(); // Maybe can choose a better codec now
	}

	u->deleteLater();

	if (qhUsers.isEmpty())
		stopThread();
}

void Server::message(Mumble::Protocol::TCPMessageType type, const QByteArray &qbaMsg, ServerUser *u) {
	ZoneScopedN(TracyConstants::TCP_PACKET_PROCESSING_ZONE);

	if (!u) {
		u = static_cast< ServerUser * >(sender());
	}

	if (u->sState == ServerUser::Authenticated) {
		u->resetActivityTime();
	}

	if (type == Mumble::Protocol::TCPMessageType::UDPTunnel) {
		int len = qbaMsg.size();
		if (len < 2 || static_cast< unsigned int >(len) > Mumble::Protocol::MAX_UDP_PACKET_SIZE) {
			// Drop messages that are too small to be senseful or that are bigger than allowed
			return;
		}

		QReadLocker rl(&qrwlVoiceThread);

		u->aiUdpFlag = 0;

		m_tcpTunnelDecoder.setProtocolVersion(u->m_version);

		if (m_tcpTunnelDecoder.decode(gsl::span< const Mumble::Protocol::byte >(
				reinterpret_cast< const Mumble::Protocol::byte * >(qbaMsg.constData()), qbaMsg.size()))) {
			if (m_tcpTunnelDecoder.getMessageType() == Mumble::Protocol::UDPMessageType::Audio) {
				Mumble::Protocol::AudioData audioData = m_tcpTunnelDecoder.getAudioData();
				// Allow all voice packets through by default.
				bool ok = true;
				// ...Unless we're in Opus mode. In Opus mode, only Opus packets are allowed.
				if (bOpus && audioData.usedCodec != Mumble::Protocol::AudioCodec::Opus) {
					ok = false;
				}

				if (ok) {
					// Add session id
					audioData.senderSession = u->uiSession;

					processMsg(u, std::move(audioData), m_tcpAudioReceivers, m_tcpAudioEncoder);
				}
			}
		}

		return;
	}

#ifdef QT_NO_DEBUG
#	define PROCESS_MUMBLE_TCP_MESSAGE(name, value)                      \
		case Mumble::Protocol::TCPMessageType::name: {                   \
			MumbleProto::name msg;                                       \
			if (msg.ParseFromArray(qbaMsg.constData(), qbaMsg.size())) { \
				msg.DiscardUnknownFields();                              \
				msg##name(u, msg);                                       \
			}                                                            \
			break;                                                       \
		}
#else
#	define PROCESS_MUMBLE_TCP_MESSAGE(name, value)                      \
		case Mumble::Protocol::TCPMessageType::name: {                   \
			MumbleProto::name msg;                                       \
			if (msg.ParseFromArray(qbaMsg.constData(), qbaMsg.size())) { \
				if (type != Mumble::Protocol::TCPMessageType::Ping) {    \
					printf("== %s:\n", #name);                           \
					msg.PrintDebugString();                              \
				}                                                        \
				msg.DiscardUnknownFields();                              \
				msg##name(u, msg);                                       \
			}                                                            \
			break;                                                       \
		}
#endif

	switch (type) { MUMBLE_ALL_TCP_MESSAGES }

#undef PROCESS_MUMBLE_TCP_MESSAGE
}

void Server::checkTimeout() {
	QList< ServerUser * > qlClose;

	qrwlVoiceThread.lockForRead();
	foreach (ServerUser *u, qhUsers) {
		if (u->activityTime() > (iTimeout * 1000)) {
			log(u, "Timeout");
			qlClose.append(u);
		}
	}
	qrwlVoiceThread.unlock();
	foreach (ServerUser *u, qlClose)
		u->disconnectSocket(true);
}

void Server::tcpTransmitData(QByteArray a, unsigned int id) {
	Connection *c = qhUsers.value(id);
	if (c) {
		QByteArray qba;
		int len = a.size();

		qba.resize(len + 6);
		unsigned char *uc = reinterpret_cast< unsigned char * >(qba.data());
		*reinterpret_cast< quint16 * >(&uc[0]) =
			qToBigEndian(static_cast< quint16 >(Mumble::Protocol::TCPMessageType::UDPTunnel));
		*reinterpret_cast< quint32 * >(&uc[2]) = qToBigEndian(static_cast< quint32 >(len));
		memcpy(uc + 6, a.constData(), len);

		c->sendMessage(qba);
		c->forceFlush();
	}
}

void Server::doSync(unsigned int id) {
	ServerUser *u = qhUsers.value(id);
	if (u) {
		log(u, "Requesting crypt-nonce resync");
		MumbleProto::CryptSetup mpcs;
		sendMessage(u, mpcs);
	}
}

void Server::sendProtoMessage(ServerUser *u, const ::google::protobuf::Message &msg,
							  Mumble::Protocol::TCPMessageType msgType) {
	QByteArray cache;
	u->sendMessage(msg, msgType, cache);
}

void Server::sendProtoAll(const ::google::protobuf::Message &msg, Mumble::Protocol::TCPMessageType msgType,
						  Version::full_t version, Version::CompareMode mode) {
	sendProtoExcept(nullptr, msg, msgType, version, mode);
}

void Server::sendProtoExcept(ServerUser *u, const ::google::protobuf::Message &msg,
							 Mumble::Protocol::TCPMessageType msgType, Version::full_t version,
							 Version::CompareMode mode) {
	QByteArray cache;
	foreach (ServerUser *usr, qhUsers)
		if ((usr != u) && (usr->sState == ServerUser::Authenticated)) {
			assert(mode == Version::CompareMode::AtLeast || mode == Version::CompareMode::LessThan);

			const bool isUnknown = version == Version::UNKNOWN;
			const bool fulfillsVersionRequirement =
				mode == Version::CompareMode::AtLeast ? usr->m_version >= version : usr->m_version < version;
			if (isUnknown || fulfillsVersionRequirement) {
				usr->sendMessage(msg, msgType, cache);
			}
		}
}

void Server::removeChannel(int id) {
	Channel *c = qhChannels.value(id);
	if (c)
		removeChannel(c);
}

void Server::removeChannel(Channel *chan, Channel *dest) {
	Channel *c;
	User *p;

	if (!dest)
		dest = chan->cParent;

	{
		QWriteLocker wl(&qrwlVoiceThread);
		chan->unlink(nullptr);
	}

	foreach (c, chan->qlChannels) { removeChannel(c, dest); }

	foreach (p, chan->qlUsers) {
		{
			QWriteLocker wl(&qrwlVoiceThread);
			chan->removeUser(p);
		}

		Channel *target = dest;
		while (target->cParent
			   && (!hasPermission(static_cast< ServerUser * >(p), target, ChanACL::Enter)
				   || isChannelFull(target, static_cast< ServerUser * >(p))))
			target = target->cParent;

		MumbleProto::UserState mpus;
		mpus.set_session(p->uiSession);
		mpus.set_channel_id(target->iId);
		userEnterChannel(p, target, mpus);
		sendAll(mpus);
		emit userStateChanged(p);
	}

	foreach (unsigned int userSession, m_channelListenerManager.getListenersForChannel(chan->iId)) {
		const ServerUser *user = qhUsers.value(userSession);
		if (!user) {
			continue;
		}

		deleteChannelListener(*user, *chan);

		// Notify that all clients that have been listening to this channel, will do so no more
		MumbleProto::UserState mpus;
		mpus.set_session(user->uiSession);
		mpus.add_listening_channel_remove(chan->iId);

		sendAll(mpus);
	}

	MumbleProto::ChannelRemove mpcr;
	mpcr.set_channel_id(chan->iId);
	sendAll(mpcr);

	removeChannelDB(chan);
	emit channelRemoved(chan);

	if (chan->cParent) {
		QWriteLocker wl(&qrwlVoiceThread);
		chan->cParent->removeChannel(chan);
	}

	delete chan;
}

bool Server::unregisterUser(int id) {
	if (!unregisterUserDB(id))
		return false;

	{
		QMutexLocker lock(&qmCache);

		foreach (Channel *c, qhChannels) {
			bool write            = false;
			QList< ChanACL * > ql = c->qlACL;

			foreach (ChanACL *acl, ql) {
				if (acl->iUserId == id) {
					c->qlACL.removeAll(acl);
					write = true;
				}
			}
			foreach (Group *g, c->qhGroups) {
				bool addrem = g->qsAdd.remove(id);
				bool remrem = g->qsRemove.remove(id);
				write       = write || addrem || remrem;
			}
			if (write)
				updateChannel(c);
		}
	}

	foreach (ServerUser *u, qhUsers) {
		if (u->iId == id) {
			clearACLCache(u);
			MumbleProto::UserState mpus;
			mpus.set_session(u->uiSession);
			mpus.set_user_id(-1);
			sendAll(mpus);

			u->iId = -1;
			break;
		}
	}
	return true;
}

void Server::userEnterChannel(User *p, Channel *c, MumbleProto::UserState &mpus) {
	if (p->cChannel == c)
		return;

	Channel *old = p->cChannel;

	{
		QWriteLocker wl(&qrwlVoiceThread);
		c->addUser(p);

		bool mayspeak = ChanACL::hasPermission(static_cast< ServerUser * >(p), c, ChanACL::Speak, nullptr);
		bool sup      = p->bSuppress;

		if (mayspeak == sup) {
			// Ok, he can speak and was suppressed, or vice versa
			p->bSuppress = !mayspeak;
			mpus.set_suppress(p->bSuppress);
		}

		if (p->bPrioritySpeaker) {
			// Clear priority speaker flag when switching channels
			p->bPrioritySpeaker = false;
			mpus.set_priority_speaker(p->bPrioritySpeaker);
		}
	}

	clearACLCache(p);
	setLastChannel(p);

	if (old && old->bTemporary && old->qlUsers.isEmpty()) {
		QCoreApplication::instance()->postEvent(this,
												new ExecEvent(boost::bind(&Server::removeChannel, this, old->iId)));
	}

	sendClientPermission(static_cast< ServerUser * >(p), c);
	if (c->cParent)
		sendClientPermission(static_cast< ServerUser * >(p), c->cParent);
}

bool Server::hasPermission(ServerUser *p, Channel *c, QFlags< ChanACL::Perm > perm) {
	QMutexLocker qml(&qmCache);
	return ChanACL::hasPermission(p, c, perm, &acCache);
}

QFlags< ChanACL::Perm > Server::effectivePermissions(ServerUser *p, Channel *c) {
	QMutexLocker qml(&qmCache);
	return ChanACL::effectivePermissions(p, c, &acCache);
}

void Server::sendClientPermission(ServerUser *u, Channel *c, bool explicitlyRequested) {
	unsigned int perm;

	if (u->iId == 0)
		return;

	{
		QMutexLocker qml(&qmCache);
		// Abuse that hasPermission will update acCache with the latest permissions (all of them,
		// not only the requested one) so that we can pull this information out of it afterwards.
		ChanACL::hasPermission(u, c, ChanACL::Enter, &acCache);
		perm = acCache.value(u)->value(c);
	}

	if (explicitlyRequested) {
		// Store the last channel the client showed explicit interest in
		u->iLastPermissionCheck = c->iId;
	}

	if (explicitlyRequested || u->qmPermissionSent.value(c->iId) != perm) {
		// Send the permission info only if the client has explicitly asked for it
		// or if the permissions have changed since the last time the client has
		// been informed about permission for this channel.
		u->qmPermissionSent.insert(c->iId, perm);

		MumbleProto::PermissionQuery mppq;
		mppq.set_channel_id(c->iId);
		mppq.set_permissions(perm);

		sendMessage(u, mppq);
	}
}

/* This function is a helper for clearACLCache and assumes qmCache is held.
 * First, check if anything actually changed, or if the list is getting awfully large,
 * because this function is potentially quite expensive.
 * If all the items are still valid; great. If they aren't, send off the last channel
 * the client expliticly asked for -- this may not be what it wants, but it's our best
 * guess.
 */

void Server::flushClientPermissionCache(ServerUser *u, MumbleProto::PermissionQuery &mppq) {
	QMap< int, unsigned int >::const_iterator i;
	bool match = (u->qmPermissionSent.count() < 20);
	for (i = u->qmPermissionSent.constBegin(); (match && (i != u->qmPermissionSent.constEnd())); ++i) {
		Channel *c = qhChannels.value(i.key());
		if (!c) {
			match = false;
		} else {
			ChanACL::hasPermission(u, c, ChanACL::Enter, &acCache);
			unsigned int perm = acCache.value(u)->value(c);
			if (perm != i.value())
				match = false;
		}
	}

	if (match)
		return;

	u->qmPermissionSent.clear();

	Channel *c = qhChannels.value(u->iLastPermissionCheck);
	if (!c) {
		c                       = u->cChannel;
		u->iLastPermissionCheck = c->iId;
	}

	ChanACL::hasPermission(u, c, ChanACL::Enter, &acCache);
	unsigned int perm = acCache.value(u)->value(c);
	u->qmPermissionSent.insert(c->iId, perm);

	mppq.Clear();
	mppq.set_channel_id(c->iId);
	mppq.set_permissions(perm);
	mppq.set_flush(true);

	sendMessage(u, mppq);
}

void Server::clearACLCache(User *p) {
	MumbleProto::PermissionQuery mppq;

	{
		QMutexLocker qml(&qmCache);

		if (p) {
			ChanACL::ChanCache *h = acCache.take(p);
			delete h;

			flushClientPermissionCache(static_cast< ServerUser * >(p), mppq);
		} else {
			foreach (ChanACL::ChanCache *h, acCache)
				delete h;
			acCache.clear();

			foreach (ServerUser *u, qhUsers)
				if (u->sState == ServerUser::Authenticated)
					flushClientPermissionCache(u, mppq);
		}

		// A change in ACLs could also change a user's suppression state
		MumbleProto::UserState mpus;
		auto processingFunction = [&](ServerUser *user) {
			bool maySpeak = ChanACL::hasPermission(user, user->cChannel, ChanACL::Speak, &acCache);

			if (maySpeak == user->bSuppress) {
				// Mirror a user's ability to speak in the current channel (by means of the ACLs) in the suppress
				// property (not being allowed to speak -> suppressed and vice versa)
				user->bSuppress = !maySpeak;

				mpus.Clear();
				mpus.set_session(user->uiSession);
				mpus.set_suppress(true);
				sendAll(mpus);
			}
		};

		if (p) {
			processingFunction(static_cast< ServerUser * >(p));
		} else {
			for (ServerUser *currentUser : qhUsers) {
				processingFunction(currentUser);
			}
		}
	}

	// A change in ACLs means that the user might be able to whisper
	// to users it didn't have permission to do before (or vice versa)
	clearWhisperTargetCache();
}

void Server::clearWhisperTargetCache() {
	QWriteLocker lock(&qrwlVoiceThread);

	foreach (ServerUser *u, qhUsers) { u->qmTargetCache.clear(); }
}

QString Server::addressToString(const QHostAddress &adr, unsigned short port) {
	HostAddress ha(adr);

	if ((Meta::mp.iObfuscate != 0)) {
		QCryptographicHash h(QCryptographicHash::Sha1);
		h.addData(reinterpret_cast< const char * >(&Meta::mp.iObfuscate), sizeof(Meta::mp.iObfuscate));
		if (adr.protocol() == QAbstractSocket::IPv4Protocol) {
			quint32 num = adr.toIPv4Address();
			h.addData(reinterpret_cast< const char * >(&num), sizeof(num));
		} else if (adr.protocol() == QAbstractSocket::IPv6Protocol) {
			Q_IPV6ADDR num = adr.toIPv6Address();
			h.addData(reinterpret_cast< const char * >(num.c), sizeof(num.c));
		}
		return QString("<<%1:%2>>").arg(QString::fromLatin1(h.result().toHex()), QString::number(port));
	}
	return QString("%1:%2").arg(ha.toString(), QString::number(port));
}

bool Server::validateUserName(const QString &name) {
	// We expect the name passed to this function to be fully trimmed already. This way we
	// prevent "empty" names (at least with the default username restriction).
	return (name.trimmed().length() == name.length() && qrUserName.exactMatch(name) && (name.length() <= 512));
}

bool Server::validateChannelName(const QString &name) {
	return (qrChannelName.exactMatch(name) && (name.length() <= 512));
}

void Server::recheckCodecVersions(ServerUser *connectingUser) {
	QMap< int, int > qmCodecUsercount;
	QMap< int, int >::const_iterator i;
	int users = 0;
	int opus  = 0;

	// Count how many users use which codec
	foreach (ServerUser *u, qhUsers) {
		if (u->qlCodecs.isEmpty() && !u->bOpus)
			continue;

		++users;
		if (u->bOpus)
			++opus;

		foreach (int version, u->qlCodecs)
			++qmCodecUsercount[version];
	}

	if (!users)
		return;

	// Enable Opus if the number of users with Opus is higher than the threshold
	bool enableOpus = ((opus * 100 / users) >= iOpusThreshold);

	// Find the best possible codec most users support
	int version       = 0;
	int maximum_users = 0;
	i                 = qmCodecUsercount.constEnd();
	do {
		--i;
		if (i.value() > maximum_users) {
			version       = i.key();
			maximum_users = i.value();
		}
	} while (i != qmCodecUsercount.constBegin());

	int current_version = bPreferAlpha ? iCodecAlpha : iCodecBeta;

	// If we don't already use the compat bitstream version set
	// it as alpha and announce it. If another codec now got the
	// majority set it as the opposite of the currently valid bPreferAlpha
	// and announce it.

	if (current_version != version) {
		if (version == static_cast< qint32 >(0x8000000b))
			bPreferAlpha = true;
		else
			bPreferAlpha = !bPreferAlpha;

		if (bPreferAlpha)
			iCodecAlpha = version;
		else
			iCodecBeta = version;
	} else if (bOpus == enableOpus) {
		if (bOpus && connectingUser && !connectingUser->bOpus) {
			sendTextMessage(
				nullptr, connectingUser, false,
				QLatin1String(
					"<strong>WARNING:</strong> Your client doesn't support the Opus codec the server is using, you "
					"won't be able to talk or hear anyone. Please upgrade to a client with Opus support."));
		}
		return;
	}

	bOpus = enableOpus;

	MumbleProto::CodecVersion mpcv;
	mpcv.set_alpha(iCodecAlpha);
	mpcv.set_beta(iCodecBeta);
	mpcv.set_prefer_alpha(bPreferAlpha);
	mpcv.set_opus(bOpus);
	sendAll(mpcv);

	if (bOpus) {
		foreach (ServerUser *u, qhUsers) {
			// Prevent connected users that could not yet declare their opus capability during msgAuthenticate from
			// being spammed. Only authenticated users and the currently connecting user (if recheck is called in
			// that context) have a reliable u->bOpus.
			if ((u->sState == ServerUser::Authenticated || u == connectingUser) && !u->bOpus) {
				sendTextMessage(nullptr, u, false,
								QLatin1String("<strong>WARNING:</strong> Your client doesn't support the Opus "
											  "codec the server is switching "
											  "to, you won't be able to talk or hear anyone. Please upgrade to a "
											  "client with Opus support."));
			}
		}
	}

	log(QString::fromLatin1("CELT codec switch %1 %2 (prefer %3) (Opus %4)")
			.arg(iCodecAlpha, 0, 16)
			.arg(iCodecBeta, 0, 16)
			.arg(bPreferAlpha ? iCodecAlpha : iCodecBeta, 0, 16)
			.arg(bOpus));
}

void Server::hashAssign(QString &dest, QByteArray &hash, const QString &src) {
	dest = src;
	if (src.length() >= 128)
		hash = sha1(src);
	else
		hash = QByteArray();
}

void Server::hashAssign(QByteArray &dest, QByteArray &hash, const QByteArray &src) {
	dest = src;
	if (src.length() >= 128)
		hash = sha1(src);
	else
		hash = QByteArray();
}

bool Server::isTextAllowed(QString &text, bool &changed) {
	changed = false;

	if (!bAllowHTML) {
		QString out;
		if (HTMLFilter::filter(text, out)) {
			changed = true;
			text    = out;
		}
		return ((iMaxTextMessageLength == 0) || (text.length() <= iMaxTextMessageLength));
	} else {
		int length = text.length();

		// No limits
		if ((iMaxTextMessageLength == 0) && (iMaxImageMessageLength == 0))
			return true;

		// Over Image limit? (If so, always fail)
		if ((iMaxImageMessageLength != 0) && (length > iMaxImageMessageLength))
			return false;

		// Under textlength?
		if ((iMaxTextMessageLength == 0) || (length <= iMaxTextMessageLength))
			return true;

		// Over textlength, under imagelength. If no XML, this is a fail.
		if (!text.contains(QLatin1Char('<')))
			return false;

		// Strip value from <img>s src attributes to check text-length only -
		// we already ensured the img-length requirement is met
		QString qsOut;
		QXmlStreamReader qxsr(QString::fromLatin1("<document>%1</document>").arg(text));
		QXmlStreamWriter qxsw(&qsOut);
		while (!qxsr.atEnd()) {
			switch (qxsr.readNext()) {
				case QXmlStreamReader::Invalid:
					return false;
				case QXmlStreamReader::StartElement: {
					if (qxsr.name() == QLatin1String("img")) {
						qxsw.writeStartElement(qxsr.namespaceUri().toString(), qxsr.name().toString());
						foreach (const QXmlStreamAttribute &a, qxsr.attributes())
							if (a.name() != QLatin1String("src"))
								qxsw.writeAttribute(a);
					} else {
						qxsw.writeCurrentToken(qxsr);
					}
				} break;
				default:
					qxsw.writeCurrentToken(qxsr);
					break;
			}
		}

		length = qsOut.length();

		return (length <= iMaxTextMessageLength);
	}
}

bool Server::isChannelFull(Channel *c, ServerUser *u) {
	if (u && hasPermission(u, c, ChanACL::Write)) {
		return false;
	}
	if (c->uiMaxUsers) {
		return static_cast< unsigned int >(c->qlUsers.count()) >= c->uiMaxUsers;
	}
	if (iMaxUsersPerChannel) {
		return c->qlUsers.count() >= iMaxUsersPerChannel;
	}
	return false;
}

bool Server::canNest(Channel *newParent, Channel *channel) const {
	const int parentLevel  = newParent ? static_cast< int >(newParent->getLevel()) : -1;
	const int channelDepth = channel ? static_cast< int >(channel->getDepth()) : 0;

	return (parentLevel + channelDepth) < iChannelNestingLimit;
}

#undef SIO_UDP_CONNRESET
#undef SENDTO