Don't listen on IPv6 address by default. Prevents network connectivity problems. Closes #1880.

src/preferences/advancedsettings.h

@@ -13,7 +13,7 @@
 #include "preferences.h"
 
 enum AdvSettingsCols {PROPERTY, VALUE};
-enum AdvSettingsRows {DISK_CACHE, DISK_CACHE_TTL, OS_CACHE, OUTGOING_PORT_MIN, OUTGOING_PORT_MAX, IGNORE_LIMIT_LAN, RECHECK_COMPLETED, LIST_REFRESH, RESOLVE_COUNTRIES, RESOLVE_HOSTS, MAX_HALF_OPEN, SUPER_SEEDING, NETWORK_IFACE, NETWORK_ADDRESS, PROGRAM_NOTIFICATIONS, TRACKER_STATUS, TRACKER_PORT,
+enum AdvSettingsRows {DISK_CACHE, DISK_CACHE_TTL, OS_CACHE, OUTGOING_PORT_MIN, OUTGOING_PORT_MAX, IGNORE_LIMIT_LAN, RECHECK_COMPLETED, LIST_REFRESH, RESOLVE_COUNTRIES, RESOLVE_HOSTS, MAX_HALF_OPEN, SUPER_SEEDING, NETWORK_IFACE, NETWORK_LISTEN_IPV6, NETWORK_ADDRESS, PROGRAM_NOTIFICATIONS, TRACKER_STATUS, TRACKER_PORT,
                     #if defined(Q_OS_WIN) || defined(Q_OS_MAC)
                       UPDATE_CHECK,
                     #endif
@@ -31,7 +31,7 @@ private:
   QSpinBox spin_cache, outgoing_ports_min, outgoing_ports_max, spin_list_refresh, spin_maxhalfopen, spin_tracker_port;
   QCheckBox cb_os_cache, cb_ignore_limits_lan, cb_recheck_completed, cb_resolve_countries, cb_resolve_hosts,
   cb_super_seeding, cb_program_notifications, cb_tracker_status, cb_confirm_torrent_deletion,
-  cb_enable_tracker_ext;
+  cb_enable_tracker_ext, cb_listen_ipv6;
   QComboBox combo_iface;
   QSpinBox spin_cache_ttl;
 #if defined(Q_OS_WIN) || defined(Q_OS_MAC)
@@ -98,6 +98,8 @@ public slots:
       pref->setNetworkInterface(combo_iface.itemData(combo_iface.currentIndex()).toString());
       pref->setNetworkInterfaceName(combo_iface.currentText());
     }
+    // Listen on IPv6 address
+    pref->setListenIPv6(cb_listen_ipv6.isChecked());
     // Network address
     QHostAddress addr(txt_network_address.text().trimmed());
     if (addr.isNull())
@@ -249,6 +251,9 @@ private slots:
       combo_iface.setCurrentIndex(i);
     }
     setRow(NETWORK_IFACE, tr("Network Interface (requires restart)"), &combo_iface);
+    // Listen on IPv6 address
+    cb_listen_ipv6.setChecked(pref->getListenIPv6());
+    setRow(NETWORK_LISTEN_IPV6, tr("Listen on IPv6 address (requires restart)"), &cb_listen_ipv6);
     // Network address
     txt_network_address.setText(pref->getNetworkAddress());
     setRow(NETWORK_ADDRESS, tr("IP Address to report to trackers (requires restart)"), &txt_network_address);

src/preferences/preferences.cpp

@@ -1248,6 +1248,14 @@ void Preferences::setNetworkInterfaceName(const QString& iface) {
   setValue("Preferences/Connection/InterfaceName", iface);
 }
 
+bool Preferences::getListenIPv6() const {
+  return value("Preferences/Connection/InterfaceListenIPv6", false).toBool();
+}
+
+void Preferences::setListenIPv6(bool enable) {
+  setValue("Preferences/Connection/InterfaceListenIPv6", enable);
+}
+
 QString Preferences::getNetworkAddress() const {
   return value("Preferences/Connection/InetAddress").toString();
 }

src/preferences/preferences.h

@@ -334,6 +334,8 @@ public:
   void setNetworkInterface(const QString& iface);
   QString getNetworkInterfaceName() const;
   void setNetworkInterfaceName(const QString& iface);
+  bool getListenIPv6() const;
+  void setListenIPv6(bool enable);
   QString getNetworkAddress() const;
   void setNetworkAddress(const QString& addr);
   bool isAnonymousModeEnabled() const;

src/qtlibtorrent/qbtsession.cpp

@@ -1896,9 +1896,17 @@ void QBtSession::setListeningPort(int port) {
   std::pair<int,int> ports(port, port);
   libtorrent::error_code ec;
   const QString iface_name = pref->getNetworkInterface();
+  const bool listen_ipv6 = pref->getListenIPv6();
   if (iface_name.isEmpty()) {
     addConsoleMessage(tr("qBittorrent is trying to listen on any interface port: %1", "e.g: qBittorrent is trying to listen on any interface port: TCP/6881").arg(QString::number(port)), "blue");
-    s->listen_on(ports, ec, 0, session::listen_no_system_port);
+    if (listen_ipv6)
+      s->listen_on(ports, ec, "::", session::listen_no_system_port);
+    else
+      s->listen_on(ports, ec, "0.0.0.0", session::listen_no_system_port);
+
+    if (ec)
+      addConsoleMessage(tr("qBittorrent failed to listen on any interface port: %1. Reason: %2", "e.g: qBittorrent failed to listen on any interface port: TCP/6881. Reason: no such interface" ).arg(QString::number(port)).arg(misc::toQStringU(ec.message())), "red");
+
     return;
   }
   // Attempt to listen on provided interface
@@ -1911,6 +1919,8 @@ void QBtSession::setListeningPort(int port) {
   QString ip;
   qDebug("This network interface has %d IP addresses", network_iface.addressEntries().size());
   foreach (const QNetworkAddressEntry &entry, network_iface.addressEntries()) {
+    if (!listen_ipv6 && (entry.ip().protocol() == QAbstractSocket::IPv6Protocol))
+      continue;
     qDebug("Trying to listen on IP %s (%s)", qPrintable(entry.ip().toString()), qPrintable(iface_name));
     s->listen_on(ports, ec, entry.ip().toString().toLatin1().constData(), session::listen_no_system_port);
     if (!ec) {