IPv4 + IPv6 dual stack sockets

Adds support for binding "dual stack" sockets (via QUdpSocket or
QTcpServer). A dual stack socket will accept incoming connections on
either IPv4 or IPv6 interfaces.

QHostAddress::Any     - use this to bind a dual stack socket
QHostAddress::AnyIPv6 - use this to bind a socket for IPv6 only
QHostAddress::AnyIPv4 - use this to bind a socket for IPv4 only

Binding to a specific address rather than one of the "any" addresses
is restricting you to a protocol anyway so no behaviour change there.
IPv6 sockets were previously dual stack on some OS and v6 only on others
Any previously meant IPv4 only

This commit implemented & tested on Windows 7, Linux (Ubuntu 10.04)
and Mac OS 10.6.7.

Windows XP and server 2003 do not support dual stack sockets, even though
they can support IPv6. On those versions, QHostAddress::Any will still
bind to IPv4 0.0.0.0 (which is also the behaviour anywhere QT_NO_IPV6 is
defined)

Autotests run:
qudpsocket (includes a new test case)
qtcpserver (includes a new test case)
qtcpsocket
qnetworkreply
qhostaddress

Task-number: QTBUG-17080
Change-Id: Id486677c4f832e18dc0ff1a86c5f5fc422c9eb4f
Reviewed-on: http://codereview.qt.nokia.com/421
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Thiago Macieira <thiago.macieira@nokia.com>
Reviewed-by: Markus Goetz

7 files changed, 111 insertions, 27 deletions

diff --git a/src/network/kernel/qhostaddress.cpp b/src/network/kernel/qhostaddress.cpp
index 7eeb4e5a51..bff351c34f 100644
--- a/src/network/kernel/qhostaddress.cpp
+++ b/src/network/kernel/qhostaddress.cpp
@@ -134,15 +134,40 @@ QHostAddressPrivate::QHostAddressPrivate()
 void QHostAddressPrivate::setAddress(quint32 a_)
 {
     a = a_;
+    //create mapped address
+    memset(&a6, 0, sizeof(a6));
+    int i;
+    for (i=15; a_ != 0; i--) {
+        a6[i] = a_ & 0xFF;
+        a_ >>=8;
+    }
+    Q_ASSERT(i >= 11);
+    a6[11] = 0xFF;
+    a6[10] = 0xFF;
     protocol = QAbstractSocket::IPv4Protocol;
     isParsed = true;
 }
 
+static bool parseMappedAddress(quint32& a, const Q_IPV6ADDR &a6)
+{
+    int i;
+    for (i=0;i<10;i++)
+        if (a6[i]) return false;
+    for (;i<12;i++)
+        if (a6[i] != 0xFF) return false;
+    a=(a6[12] << 24) | (a6[13] << 16) | (a6[14] << 8) | a6[15];
+    return true;
+}
+
 void QHostAddressPrivate::setAddress(const quint8 *a_)
 {
     for (int i = 0; i < 16; i++)
         a6[i] = a_[i];
-    protocol = QAbstractSocket::IPv6Protocol;
+    a = 0;
+    if (parseMappedAddress(a, a6))
+        protocol = QAbstractSocket::IPv4Protocol;
+    else
+        protocol = QAbstractSocket::IPv6Protocol;
     isParsed = true;
 }
 
@@ -150,7 +175,10 @@ void QHostAddressPrivate::setAddress(const Q_IPV6ADDR &a_)
 {
     a6 = a_;
     a = 0;
-    protocol = QAbstractSocket::IPv6Protocol;
+    if (parseMappedAddress(a, a6))
+        protocol = QAbstractSocket::IPv4Protocol;
+    else
+        protocol = QAbstractSocket::IPv6Protocol;
     isParsed = true;
 }
 
@@ -447,8 +475,9 @@ void QNetmaskAddress::setPrefixLength(QAbstractSocket::NetworkLayerProtocol prot
     \value LocalHost The IPv4 localhost address. Equivalent to QHostAddress("127.0.0.1").
     \value LocalHostIPv6 The IPv6 localhost address. Equivalent to QHostAddress("::1").
     \value Broadcast The IPv4 broadcast address. Equivalent to QHostAddress("255.255.255.255").
-    \value Any The IPv4 any-address. Equivalent to QHostAddress("0.0.0.0").
-    \value AnyIPv6 The IPv6 any-address. Equivalent to QHostAddress("::").
+    \value AnyIPv4 The IPv4 any-address. Equivalent to QHostAddress("0.0.0.0"). A socket bound with this address will listen only on IPv4 interaces.
+    \value AnyIPv6 The IPv6 any-address. Equivalent to QHostAddress("::"). A socket bound with this address will listen only on IPv6 interaces.
+    \value Any The dual stack any-address. A socket bound with this address will listen on both IPv4 and IPv6 interfaces.
 */
 
 /*!  Constructs a host address object with the IP address 0.0.0.0.
@@ -548,12 +577,16 @@ QHostAddress::QHostAddress(SpecialAddress address)
     case LocalHostIPv6:
         setAddress(QLatin1String("::1"));
         break;
-    case Any:
+    case AnyIPv4:
         setAddress(QLatin1String("0.0.0.0"));
         break;
     case AnyIPv6:
         setAddress(QLatin1String("::"));
         break;
+    case Any:
+        d->clear();
+        d->protocol = QAbstractSocket::AnyIPProtocol;
+        break;
     }
 }
 
@@ -679,8 +712,11 @@ void QHostAddress::setAddress(const struct sockaddr *sockaddr)
     For example, if the address is 127.0.0.1, the returned value is
     2130706433 (i.e. 0x7f000001).
 
-    This value is only valid if the Protocol() is
-    \l{QAbstractSocket::}{IPv4Protocol}.
+    This value is valid if the protocol() is
+    \l{QAbstractSocket::}{IPv4Protocol},
+    or if the protocol is
+    \l{QAbstractSocket::}{IPv6Protocol},
+    and the IPv6 address is an IPv4 mapped address. (RFC4291)
 
     \sa toString()
 */
@@ -705,8 +741,11 @@ QAbstractSocket::NetworkLayerProtocol QHostAddress::protocol() const
 
     \snippet doc/src/snippets/code/src_network_kernel_qhostaddress.cpp 0
 
-    This value is only valid if the protocol() is
+    This value is valid if the protocol() is
     \l{QAbstractSocket::}{IPv6Protocol}.
+    If the protocol is
+    \l{QAbstractSocket::}{IPv4Protocol},
+    then the address is returned an an IPv4 mapped IPv6 address. (RFC4291)
 
     \sa toString()
 */
@@ -722,13 +761,15 @@ Q_IPV6ADDR QHostAddress::toIPv6Address() const
     For example, if the address is the IPv4 address 127.0.0.1, the
     returned string is "127.0.0.1". For IPv6 the string format will 
     follow the RFC5952 recommendation.
+    For QHostAddress::Any, its IPv4 address will be returned ("0.0.0.0")
 
     \sa toIPv4Address()
 */
 QString QHostAddress::toString() const
 {
     QT_ENSURE_PARSED(this);
-    if (d->protocol == QAbstractSocket::IPv4Protocol) {
+    if (d->protocol == QAbstractSocket::IPv4Protocol
+        || d->protocol == QAbstractSocket::AnyIPProtocol) {
         quint32 i = toIPv4Address();
         QString s;
         s.sprintf("%d.%d.%d.%d", (i>>24) & 0xff, (i>>16) & 0xff,
@@ -1183,6 +1224,9 @@ QDataStream &operator>>(QDataStream &in, QHostAddress &address)
         address.setScopeId(scope);
     }
         break;
+    case QAbstractSocket::AnyIPProtocol:
+        address = QHostAddress::Any;
+        break;
     default:
         address.clear();
         in.setStatus(QDataStream::ReadCorruptData);
diff --git a/src/network/kernel/qhostaddress.h b/src/network/kernel/qhostaddress.h
index 486f2322ae..efb3198fc0 100644
--- a/src/network/kernel/qhostaddress.h
+++ b/src/network/kernel/qhostaddress.h
@@ -76,7 +76,8 @@ public:
         LocalHost,
         LocalHostIPv6,
         Any,
-        AnyIPv6
+        AnyIPv6,
+        AnyIPv4
     };
 
     QHostAddress();
diff --git a/src/network/socket/qabstractsocket.h b/src/network/socket/qabstractsocket.h
index 1959fabdfc..2717ceb58a 100644
--- a/src/network/socket/qabstractsocket.h
+++ b/src/network/socket/qabstractsocket.h
@@ -74,6 +74,7 @@ public:
     enum NetworkLayerProtocol {
         IPv4Protocol,
         IPv6Protocol,
+        AnyIPProtocol,
         UnknownNetworkLayerProtocol = -1
     };
     enum SocketError {
diff --git a/src/network/socket/qnativesocketengine_p.h b/src/network/socket/qnativesocketengine_p.h
index c5c4b325d0..a024cd42d1 100644
--- a/src/network/socket/qnativesocketengine_p.h
+++ b/src/network/socket/qnativesocketengine_p.h
@@ -74,6 +74,11 @@ struct qt_sockaddr_storage {
       char __ss_pad2[QT_SS_PAD2SIZE];
 };
 
+#ifdef Q_OS_WIN
+#define QT_SOCKLEN_T int
+#define QT_SOCKOPTLEN_T int
+#endif
+
 // sockaddr_in6 size changed between old and new SDK
 // Only the new version is the correct one, so always
 // use this structure.
@@ -265,6 +270,10 @@ public:
     int nativeSelect(int timeout, bool selectForRead) const;
     int nativeSelect(int timeout, bool checkRead, bool checkWrite,
 		     bool *selectForRead, bool *selectForWrite) const;
+#ifdef Q_OS_WIN
+    void setPortAndAddress(sockaddr_in * sockAddrIPv4, qt_sockaddr_in6 * sockAddrIPv6,
+                           quint16 port, const QHostAddress & address, sockaddr ** sockAddrPtr, QT_SOCKLEN_T *sockAddrSize);
+#endif
 
     void nativeClose();
 
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp
index 39570c8c04..26053981ce 100644
--- a/src/network/socket/qnativesocketengine_unix.cpp
+++ b/src/network/socket/qnativesocketengine_unix.cpp
@@ -163,7 +163,7 @@ bool QNativeSocketEnginePrivate::createNewSocket(QAbstractSocket::SocketType soc
                                          QAbstractSocket::NetworkLayerProtocol socketProtocol)
 {
 #ifndef QT_NO_IPV6
-    int protocol = (socketProtocol == QAbstractSocket::IPv6Protocol) ? AF_INET6 : AF_INET;
+    int protocol = (socketProtocol == QAbstractSocket::IPv6Protocol || socketProtocol == QAbstractSocket::AnyIPProtocol) ? AF_INET6 : AF_INET;
 #else
     Q_UNUSED(socketProtocol);
     int protocol = AF_INET;
@@ -495,7 +495,14 @@ bool QNativeSocketEnginePrivate::nativeBind(const QHostAddress &address, quint16
 #if !defined(QT_NO_IPV6)
     struct sockaddr_in6 sockAddrIPv6;
 
-    if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+    if (address.protocol() == QAbstractSocket::IPv6Protocol || address.protocol() == QAbstractSocket::AnyIPProtocol) {
+#ifdef IPV6_V6ONLY
+        int ipv6only = 0;
+        if (address.protocol() == QAbstractSocket::IPv6Protocol)
+            ipv6only = 1;
+        //default value of this socket option varies depending on unix variant (or system configuration on BSD), so always set it explicitly
+        ::setsockopt(socketDescriptor, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&ipv6only, sizeof(ipv6only) );
+#endif
         memset(&sockAddrIPv6, 0, sizeof(sockAddrIPv6));
         sockAddrIPv6.sin6_family = AF_INET6;
         sockAddrIPv6.sin6_port = htons(port);
@@ -866,7 +873,8 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
 
 #if !defined(QT_NO_IPV6)
     struct sockaddr_in6 sockAddrIPv6;
-    if (host.protocol() == QAbstractSocket::IPv6Protocol) {
+    if (host.protocol() == QAbstractSocket::IPv6Protocol
+        || socketProtocol == QAbstractSocket::IPv6Protocol) {
     memset(&sockAddrIPv6, 0, sizeof(sockAddrIPv6));
     sockAddrIPv6.sin6_family = AF_INET6;
     sockAddrIPv6.sin6_port = htons(port);
diff --git a/src/network/socket/qnativesocketengine_win.cpp b/src/network/socket/qnativesocketengine_win.cpp
index 88b87b98fe..ba62bd6da2 100644
--- a/src/network/socket/qnativesocketengine_win.cpp
+++ b/src/network/socket/qnativesocketengine_win.cpp
@@ -159,11 +159,6 @@ static QByteArray qt_prettyDebug(const char *data, int len, int maxLength)
 #define SO_EXCLUSIVEADDRUSE ((int)(~SO_REUSEADDR)) /* disallow local address reuse */
 #endif
 
-//###
-#define QT_SOCKLEN_T int
-#define QT_SOCKOPTLEN_T int
-
-
 /*
     Extracts the port and address from a sockaddr, and stores them in
     \a port and \a addr if they are non-null.
@@ -202,11 +197,13 @@ static inline void qt_socket_getPortAndAddress(SOCKET socketDescriptor, const qt
 
     Sets the port and address to a sockaddr. Requires that sa point to the IPv6 struct if the address is IPv6.
 */
-static inline void qt_socket_setPortAndAddress(SOCKET socketDescriptor, sockaddr_in * sockAddrIPv4, qt_sockaddr_in6 * sockAddrIPv6,
+void QNativeSocketEnginePrivate::setPortAndAddress(sockaddr_in * sockAddrIPv4, qt_sockaddr_in6 * sockAddrIPv6,
                                                quint16 port, const QHostAddress & address, sockaddr ** sockAddrPtr, QT_SOCKLEN_T *sockAddrSize)
 {
 #if !defined(QT_NO_IPV6)
-    if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+    if (address.protocol() == QAbstractSocket::IPv6Protocol
+        || address.protocol() == QAbstractSocket::AnyIPProtocol
+        || socketProtocol == QAbstractSocket::IPv6Protocol) {
         memset(sockAddrIPv6, 0, sizeof(qt_sockaddr_in6));
         sockAddrIPv6->sin6_family = AF_INET6;
         sockAddrIPv6->sin6_scope_id = address.scopeId().toInt();
@@ -306,7 +303,9 @@ bool QNativeSocketEnginePrivate::createNewSocket(QAbstractSocket::SocketType soc
     }
     */
 
-    int protocol = (socketProtocol == QAbstractSocket::IPv6Protocol) ? AF_INET6 : AF_INET;
+    //Windows XP and 2003 support IPv6 but not dual stack sockets
+    int protocol = (socketProtocol == QAbstractSocket::IPv6Protocol
+        || (socketProtocol == QAbstractSocket::AnyIPProtocol && QSysInfo::windowsVersion() >= QSysInfo::WV_6_0)) ? AF_INET6 : AF_INET;
     int type = (socketType == QAbstractSocket::UdpSocket) ? SOCK_DGRAM : SOCK_STREAM;
     // MSDN KB179942 states that on winnt 4 WSA_FLAG_OVERLAPPED is needed if socket is to be non blocking
     // and recomends alwasy doing it for cross windows version comapablity.
@@ -602,7 +601,7 @@ bool QNativeSocketEnginePrivate::nativeConnect(const QHostAddress &address, quin
     struct sockaddr *sockAddrPtr = 0;
     QT_SOCKLEN_T sockAddrSize = 0;
 
-    qt_socket_setPortAndAddress(socketDescriptor, &sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
+    setPortAndAddress(&sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
 
     forever {
         int connectResult = ::WSAConnect(socketDescriptor, sockAddrPtr, sockAddrSize, 0,0,0,0);
@@ -708,19 +707,35 @@ bool QNativeSocketEnginePrivate::nativeConnect(const QHostAddress &address, quin
 bool QNativeSocketEnginePrivate::nativeBind(const QHostAddress &a, quint16 port)
 {
     QHostAddress address = a;
+    DWORD ipv6only = 0;
     switch (address.protocol()) {
     case QAbstractSocket::IPv6Protocol:
         if (address.toIPv6Address()[0] == 0xff) {
             // binding to a multicast address
             address = QHostAddress(QHostAddress::AnyIPv6);
         }
+#if !defined (QT_NO_IPV6) && defined (IPV6_V6ONLY)
+        //This is default in current windows versions, it may change in future so set it explicitly
+        if (QSysInfo::windowsVersion() >= QSysInfo::WV_6_0) {
+            ipv6only = 1;
+            ipv6only = ::setsockopt(socketDescriptor, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&ipv6only, sizeof(ipv6only) );
+        }
+#endif
         break;
     case QAbstractSocket::IPv4Protocol:
         if ((address.toIPv4Address() & 0xffff0000) == 0xefff0000) {
             // binding to a multicast address
-            address = QHostAddress(QHostAddress::Any);
+            address = QHostAddress(QHostAddress::AnyIPv4);
         }
         break;
+    case QAbstractSocket::AnyIPProtocol:
+#if !defined (QT_NO_IPV6) && defined (IPV6_V6ONLY)
+        if (QSysInfo::windowsVersion() >= QSysInfo::WV_6_0)
+            ipv6only = ::setsockopt(socketDescriptor, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&ipv6only, sizeof(ipv6only) );
+        else
+#endif
+            address = QHostAddress(QHostAddress::AnyIPv4); //xp/WS2003 and earlier don't support dual stack, so bind to IPv4
+        break;
     default:
         break;
     }
@@ -730,7 +745,7 @@ bool QNativeSocketEnginePrivate::nativeBind(const QHostAddress &a, quint16 port)
     struct sockaddr *sockAddrPtr = 0;
     QT_SOCKLEN_T sockAddrSize = 0;
 
-    qt_socket_setPortAndAddress(socketDescriptor, &sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
+    setPortAndAddress(&sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
 
 
     int bindResult = ::bind(socketDescriptor, sockAddrPtr, sockAddrSize);
@@ -1182,7 +1197,7 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
     struct sockaddr *sockAddrPtr = 0;
     QT_SOCKLEN_T sockAddrSize = 0;
 
-    qt_socket_setPortAndAddress(socketDescriptor, &sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
+    setPortAndAddress(&sockAddrIPv4, &sockAddrIPv6, port, address, &sockAddrPtr, &sockAddrSize);
 
     WSABUF buf;
 #if !defined(Q_OS_WINCE)
diff --git a/src/network/socket/qsocks5socketengine.cpp b/src/network/socket/qsocks5socketengine.cpp
index ab757987f6..514a7a0f6f 100644
--- a/src/network/socket/qsocks5socketengine.cpp
+++ b/src/network/socket/qsocks5socketengine.cpp
@@ -827,7 +827,7 @@ void QSocks5SocketEnginePrivate::sendRequestMethod()
         //### set error code ....
         return;
     } else if (!peerName.isEmpty() && !qt_socks5_set_host_name_and_port(peerName, port, &buf)) {
-        QSOCKS5_DEBUG << "error setting address" << address << " : " << port;
+        QSOCKS5_DEBUG << "error setting peer name" << peerName << " : " << port;
         //### set error code ....
         return;
     }
@@ -1325,12 +1325,18 @@ void QSocks5SocketEnginePrivate::_q_udpSocketReadNotification()
 }
 #endif // QT_NO_UDPSOCKET
 
-bool QSocks5SocketEngine::bind(const QHostAddress &address, quint16 port)
+bool QSocks5SocketEngine::bind(const QHostAddress &addr, quint16 port)
 {
     Q_D(QSocks5SocketEngine);
 
     // when bind wee will block until the bind is finished as the info from the proxy server is needed
 
+    QHostAddress address;
+    if (addr.protocol() == QAbstractSocket::AnyIPProtocol)
+        address = QHostAddress::AnyIPv4; //SOCKS5 doesnt support dual stack, and there isn't any implementation of udp on ipv6 yet
+    else
+        address = addr;
+
     if (!d->data) {
         if (socketType() == QAbstractSocket::TcpSocket) {
             d->initialize(QSocks5SocketEnginePrivate::BindMode);