From caa5bdcad5693518c08b03402c19c96a24086639 Mon Sep 17 00:00:00 2001
From: Jeremy Lainé <jeremy.laine@m4x.org>
Date: Wed, 26 Aug 2015 21:38:13 +0200
Subject: ICE: do not send STUN check for incompatible addresses

---
 src/base/QXmppStun.cpp | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

(limited to 'src/base/QXmppStun.cpp')

diff --git a/src/base/QXmppStun.cpp b/src/base/QXmppStun.cpp
index b8313881..7a835ad5 100644
--- a/src/base/QXmppStun.cpp
+++ b/src/base/QXmppStun.cpp
@@ -123,6 +123,13 @@ static bool isLoopbackAddress(const QHostAddress &addr)
     return (addr.toIPv4Address() & 0xff000000) == 0x7f000000;
 }
 
+// Returns true if the two addresses are compatible.
+static bool isCompatibleAddress(const QHostAddress &a1, const QHostAddress &a2)
+{
+    return a1.protocol() == a2.protocol() &&
+           isIPv6LinkLocalAddress(a1) == isIPv6LinkLocalAddress(a2);
+}
+
 static bool decodeAddress(QDataStream &stream, quint16 a_length, QHostAddress &address, quint16 &port, const QByteArray &xorId = QByteArray())
 {
     if (a_length < 4)
@@ -1976,11 +1983,9 @@ bool QXmppIceComponent::addRemoteCandidate(const QXmppJingleCandidate &candidate
     d->remoteCandidates << candidate;
 
     foreach (QXmppIceTransport *transport, d->transports) {
-        // do not pair IPv4 with IPv6 or global with link-local addresses
+        // only pair compatible addresses
         const QXmppJingleCandidate local = transport->localCandidate(d->component);
-
-        if (local.host().protocol() != candidate.host().protocol() ||
-            isIPv6LinkLocalAddress(local.host()) != isIPv6LinkLocalAddress(candidate.host()))
+        if (!isCompatibleAddress(local.host(), candidate.host()))
             continue;
 
         CandidatePair *pair = new CandidatePair(d->component, d->iceControlling, this);
@@ -2056,6 +2061,10 @@ void QXmppIceComponent::setSockets(QList<QUdpSocket*> sockets)
         QXmppStunMessage request;
         request.setType(QXmppStunMessage::Binding | QXmppStunMessage::Request);
         foreach (QXmppIceTransport *transport, d->transports) {
+            const QXmppJingleCandidate local = transport->localCandidate(d->component);
+            if (!isCompatibleAddress(local.host(), d->stunHost))
+                continue;
+
             request.setId(QXmppUtils::generateRandomBytes(STUN_ID_SIZE));
             QXmppStunTransaction *transaction = new QXmppStunTransaction(request, this);
             d->stunTransactions.insert(transaction, transport);
-- 
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