From c82d40749dc1ce816333e84d7f3232e59fbe2058 Mon Sep 17 00:00:00 2001 From: Robin Burchell Date: Fri, 30 Mar 2012 16:23:24 +0200 Subject: Fix multicast join/leave when binding to QHostAddress::Any. On OS X and Windows, this was not working, because the socket was being bound in v6 mode (due to ::Any being for dual mode), but the address passed was a v4 address, meaning it took the wrong codepath. Linux, strangely, apparently works anyway. This is fixable in OS X (by using the v6 join path when bound in v6/dual mode), but the same fix doesn't work on Windows, failing with WSAEADDRNOTAVAIL. Don't allow this behaviour, and provide a sane error message telling the user what to do instead. Done-with: Shane Kearns Task-number: QTBUG-25047 Change-Id: Iaf5bbee82e13ac92e11b60c558f5af9ce26f474b Reviewed-by: Shane Kearns --- src/network/socket/qnativesocketengine.cpp | 13 +++++++++++++ src/network/socket/qudpsocket.cpp | 4 ++++ 2 files changed, 17 insertions(+) (limited to 'src') diff --git a/src/network/socket/qnativesocketengine.cpp b/src/network/socket/qnativesocketengine.cpp index a34b19f7ef..8fac3613c0 100644 --- a/src/network/socket/qnativesocketengine.cpp +++ b/src/network/socket/qnativesocketengine.cpp @@ -637,6 +637,19 @@ bool QNativeSocketEngine::joinMulticastGroup(const QHostAddress &groupAddress, Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::joinMulticastGroup(), false); Q_CHECK_STATE(QNativeSocketEngine::joinMulticastGroup(), QAbstractSocket::BoundState, false); Q_CHECK_TYPE(QNativeSocketEngine::joinMulticastGroup(), QAbstractSocket::UdpSocket, false); + + // if the user binds a socket to an IPv6 address (or QHostAddress::Any) and + // then attempts to join an IPv4 multicast group, this won't work on + // Windows. In order to make this cross-platform, we warn & fail on all + // platforms. + if (groupAddress.protocol() == QAbstractSocket::IPv4Protocol && + (d->socketProtocol == QAbstractSocket::IPv6Protocol || + d->socketProtocol == QAbstractSocket::AnyIPProtocol)) { + qWarning("QAbstractSocket: cannot bind to QHostAddress::Any (or an IPv6 address) and join an IPv4 multicast group"); + qWarning("QAbstractSocket: bind to QHostAddress::AnyIPv4 instead if you want to do this"); + return false; + } + return d->nativeJoinMulticastGroup(groupAddress, iface); } diff --git a/src/network/socket/qudpsocket.cpp b/src/network/socket/qudpsocket.cpp index ec751c289e..23c1956ec5 100644 --- a/src/network/socket/qudpsocket.cpp +++ b/src/network/socket/qudpsocket.cpp @@ -178,6 +178,10 @@ QUdpSocket::~QUdpSocket() interface chosen by the operating system. The socket must be in BoundState, otherwise an error occurs. + Note that if you are attempting to join an IPv4 group, your socket must not + be bound using IPv6 (or in dual mode, using QHostAddress::Any). You must use + QHostAddress::AnyIPv4 instead. + This function returns true if successful; otherwise it returns false and sets the socket error accordingly. -- cgit v1.2.3