rename "source" directory to "src"

1 files changed, 979 insertions, 0 deletions

diff --git a/src/QXmppStun.cpp b/src/QXmppStun.cpp
new file mode 100644
index 00000000..5bd3fd54
--- /dev/null
+++ b/src/QXmppStun.cpp
@@ -0,0 +1,979 @@
+/*
+ * Copyright (C) 2008-2010 The QXmpp developers
+ *
+ * Author:
+ *	Jeremy Lainé
+ *
+ * Source:
+ *	http://code.google.com/p/qxmpp
+ *
+ * This file is a part of QXmpp library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ */
+
+#define QXMPP_DEBUG_STUN
+
+#include <QCryptographicHash>
+#include <QDebug>
+#include <QNetworkInterface>
+#include <QUdpSocket>
+#include <QTimer>
+
+#include "QXmppStun.h"
+#include "QXmppUtils.h"
+
+#define ID_SIZE 12
+
+static const quint32 STUN_MAGIC = 0x2112A442;
+static const quint16 STUN_HEADER = 20;
+static const quint8 STUN_IPV4 = 0x01;
+static const quint8 STUN_IPV6 = 0x02;
+
+enum MessageType {
+    BindingRequest       = 0x0001,
+    BindingIndication    = 0x0011,
+    BindingResponse      = 0x0101,
+    BindingError         = 0x0111,
+    SharedSecretRequest  = 0x0002,
+    SharedSecretResponse = 0x0102,
+    SharedSecretError    = 0x0112,
+};
+
+enum AttributeType {
+    MappedAddress    = 0x0001,
+    Username         = 0x0006,
+    MessageIntegrity = 0x0008,
+    ErrorCode        = 0x0009,
+    XorMappedAddress = 0x0020,
+    Priority         = 0x0024,
+    UseCandidate     = 0x0025,
+    Software         = 0x8022,
+    Fingerprint      = 0x8028,
+    IceControlled    = 0x8029,
+    IceControlling   = 0x802a,
+    OtherAddress     = 0x802c,
+};
+
+static bool decodeAddress(QDataStream &stream, quint16 a_length, QHostAddress &address, quint16 &port)
+{
+    if (a_length < 4)
+        return false;
+    quint8 reserved, protocol;
+    stream >> reserved;
+    stream >> protocol;
+    stream >> port;
+    if (protocol == STUN_IPV4)
+    {
+        if (a_length != 8)
+            return false;
+        quint32 addr;
+        stream >> addr;
+        address = QHostAddress(addr);
+    } else if (protocol == STUN_IPV6) {
+        if (a_length != 20)
+            return false;
+        Q_IPV6ADDR addr;
+        stream.readRawData((char*)&addr, sizeof(addr));
+        address = QHostAddress(addr);
+    } else {
+        return false;
+    }
+    return true;
+}
+
+static void encodeAddress(QDataStream &stream, const QHostAddress &address, quint16 port)
+{
+    stream << quint16(8);
+    stream << quint8(0);
+    if (address.protocol() == QAbstractSocket::IPv4Protocol)
+    {
+        stream << quint8(STUN_IPV4);
+        stream << port;
+        stream << address.toIPv4Address();
+    } else if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+        stream << quint8(STUN_IPV6);
+        stream << port;
+        Q_IPV6ADDR addr = address.toIPv6Address();
+        stream.writeRawData((char*)&addr, sizeof(addr));
+    }
+}
+
+static void encodeString(QDataStream &stream, const QString &string)
+{
+    const QByteArray utf8string = string.toUtf8();
+    stream << quint16(utf8string.size());
+    stream.writeRawData(utf8string.data(), utf8string.size());
+    if (utf8string.size() % 4)
+    {
+        const QByteArray padding(4 - (utf8string.size() % 4), 0);
+        stream.writeRawData(padding.data(), padding.size());
+    }
+}
+
+static QByteArray randomByteArray(int length)
+{
+    QByteArray result(length, 0);
+    for (int i = 0; i < length; ++i)
+        result[i] = quint8(qrand() % 255);
+    return result;
+}
+
+/// Constructs a new QXmppStunMessage.
+
+QXmppStunMessage::QXmppStunMessage()
+    : errorCode(0),
+    priority(0),
+    mappedPort(0),
+    otherPort(0),
+    xorMappedPort(0),
+    useCandidate(false)
+{
+    m_id = QByteArray(ID_SIZE, 0);
+}
+
+QByteArray QXmppStunMessage::id() const
+{
+    return m_id;
+}
+
+void QXmppStunMessage::setId(const QByteArray &id)
+{
+    Q_ASSERT(id.size() == ID_SIZE);
+    m_id = id;
+}
+
+quint16 QXmppStunMessage::type() const
+{
+    return m_type;
+}
+
+void QXmppStunMessage::setType(quint16 type)
+{
+    m_type = type;
+}
+
+/// Decodes a QXmppStunMessage and checks its integrity using the given
+/// password.
+///
+/// \param buffer
+/// \param password
+
+bool QXmppStunMessage::decode(const QByteArray &buffer, const QString &password, QStringList *errors)
+{
+    QStringList silent;
+    if (!errors)
+        errors = &silent;
+
+    if (buffer.size() < STUN_HEADER)
+    {
+        *errors << QLatin1String("Received a truncated STUN packet");
+        return false;
+    }
+
+    // parse STUN header
+    QDataStream stream(buffer);
+    quint16 length;
+    quint32 cookie;
+    stream >> m_type;
+    stream >> length;
+    stream >> cookie;
+    stream.readRawData(m_id.data(), m_id.size());
+
+    if (cookie != STUN_MAGIC || length != buffer.size() - STUN_HEADER)
+    {
+        *errors << QLatin1String("Received an invalid STUN packet");
+        return false;
+    }
+
+    // parse STUN attributes
+    int done = 0;
+    bool after_integrity = false;
+    while (done < length)
+    {
+        quint16 a_type, a_length;
+        stream >> a_type;
+        stream >> a_length;
+        const int pad_length = 4 * ((a_length + 3) / 4) - a_length;
+
+        // only FINGERPRINT is allowed after MESSAGE-INTEGRITY
+        if (after_integrity && a_type != Fingerprint)
+        {
+            *errors << QString("Skipping attribute %1 after MESSAGE-INTEGRITY").arg(QString::number(a_type));
+            stream.skipRawData(a_length + pad_length);
+            done += 4 + a_length + pad_length;
+            continue;
+        }
+
+        if (a_type == Priority)
+        {
+            // PRIORITY
+            if (a_length != sizeof(priority))
+                return false;
+            stream >> priority;
+
+        } else if (a_type == ErrorCode) {
+
+            // ERROR-CODE
+            if (a_length < 4)
+                return false;
+            quint16 reserved;
+            quint8 errorCodeHigh, errorCodeLow;
+            stream >> reserved;
+            stream >> errorCodeHigh;
+            stream >> errorCodeLow;
+            errorCode = errorCodeHigh * 100 + errorCodeLow;
+            QByteArray phrase(a_length - 4, 0);
+            stream.readRawData(phrase.data(), phrase.size());
+            errorPhrase = QString::fromUtf8(phrase);
+
+        } else if (a_type == UseCandidate) {
+
+            // USE-CANDIDATE
+            if (a_length != 0)
+                return false;
+            useCandidate = true;
+
+        } else if (a_type == Software) {
+
+            // SOFTWARE
+            QByteArray utf8Software(a_length, 0);
+            stream.readRawData(utf8Software.data(), utf8Software.size());
+            software = QString::fromUtf8(utf8Software);
+
+        } else if (a_type == MappedAddress) {
+
+            // MAPPED-ADDRESS
+            if (!decodeAddress(stream, a_length, mappedHost, mappedPort))
+            {
+                *errors << QLatin1String("Bad MAPPED-ADDRESS");
+                return false;
+            }
+
+        } else if (a_type == OtherAddress) {
+
+            // OTHER-ADDRESS
+            if (!decodeAddress(stream, a_length, otherHost, otherPort))
+            {
+                *errors << QLatin1String("Bad OTHER-ADDRESS");
+                return false;
+            }
+
+        } else if (a_type == XorMappedAddress) {
+
+            // XOR-MAPPED-ADDRESS
+            if (a_length < 4)
+                return false;
+            quint8 reserved, protocol;
+            quint16 xport;
+            stream >> reserved;
+            stream >> protocol;
+            stream >> xport;
+            xorMappedPort = xport ^ (STUN_MAGIC >> 16);
+            if (protocol == STUN_IPV4)
+            {
+                if (a_length != 8)
+                    return false;
+                quint32 xaddr;
+                stream >> xaddr;
+                xorMappedHost = QHostAddress(xaddr ^ STUN_MAGIC);
+            } else if (protocol == STUN_IPV6) {
+                if (a_length != 20)
+                    return false;
+                QByteArray xaddr(16, 0);
+                stream.readRawData(xaddr.data(), xaddr.size());
+                QByteArray xpad;
+                QDataStream(&xpad, QIODevice::WriteOnly) << STUN_MAGIC;
+                xpad += m_id;
+                Q_IPV6ADDR addr;
+                for (int i = 0; i < 16; i++)
+                    addr[i] = xaddr[i] ^ xpad[i];
+                xorMappedHost = QHostAddress(addr);
+            } else {
+                *errors << QString("Bad protocol %1").arg(QString::number(protocol));
+                return false;
+            }
+
+        } else if (a_type == MessageIntegrity) {
+
+            // MESSAGE-INTEGRITY
+            if (a_length != 20)
+                return false;
+            QByteArray integrity(20, 0);
+            stream.readRawData(integrity.data(), integrity.size());
+
+            // check HMAC-SHA1
+            if (!password.isEmpty())
+            {
+                const QByteArray key = password.toUtf8();
+                QByteArray copy = buffer.left(STUN_HEADER + done);
+                setBodyLength(copy, done + 24);
+                if (integrity != generateHmacSha1(key, copy))
+                {
+                    *errors << QLatin1String("Bad message integrity");
+                    return false;
+                }
+            }
+
+            // from here onwards, only FINGERPRINT is allowed
+            after_integrity = true;
+
+        } else if (a_type == Fingerprint) {
+
+            // FINGERPRINT
+            if (a_length != 4)
+                return false;
+            quint32 fingerprint;
+            stream >> fingerprint;
+
+            // check CRC32
+            QByteArray copy = buffer.left(STUN_HEADER + done);
+            setBodyLength(copy, done + 8);
+            const quint32 expected = generateCrc32(copy) ^ 0x5354554eL;
+            if (fingerprint != expected)
+            {
+                *errors << QLatin1String("Bad fingerprint");
+                return false;
+            }
+
+            // stop parsing, no more attributes are allowed
+            return true;
+
+        } else if (a_type == IceControlling) {
+
+            /// ICE-CONTROLLING
+            if (a_length != 8)
+                return false;
+            iceControlling.resize(8);
+            stream.readRawData(iceControlling.data(), iceControlling.size());
+
+         } else if (a_type == IceControlled) {
+
+            /// ICE-CONTROLLED
+            if (a_length != 8)
+                return false;
+            iceControlled.resize(8);
+            stream.readRawData(iceControlled.data(), iceControlled.size());
+
+        } else if (a_type == Username) {
+
+            // USERNAME
+            QByteArray utf8Username(a_length, 0);
+            stream.readRawData(utf8Username.data(), utf8Username.size());
+            username = QString::fromUtf8(utf8Username);
+
+        } else {
+
+            // Unknown attribute
+            stream.skipRawData(a_length);
+            *errors << QString("Skipping unknown attribute %1").arg(QString::number(a_type));
+
+        }
+        stream.skipRawData(pad_length);
+        done += 4 + a_length + pad_length;
+    }
+    return true;
+}
+
+/// Encodes the current QXmppStunMessage, optionally calculating the
+/// message integrity attribute using the given password.
+/// 
+/// \param password
+
+QByteArray QXmppStunMessage::encode(const QString &password) const
+{
+    QByteArray buffer;
+    QDataStream stream(&buffer, QIODevice::WriteOnly);
+
+    // encode STUN header
+    quint16 length = 0;
+    stream << m_type;
+    stream << length;
+    stream << STUN_MAGIC;
+    stream.writeRawData(m_id.data(), m_id.size());
+
+    // MAPPED-ADDRESS
+    if (mappedPort && !mappedHost.isNull() &&
+        (mappedHost.protocol() == QAbstractSocket::IPv4Protocol ||
+         mappedHost.protocol() == QAbstractSocket::IPv6Protocol))
+    {
+        stream << quint16(MappedAddress);
+        encodeAddress(stream, mappedHost, mappedPort);
+    }
+
+    // OTHER-ADDRESS
+    if (otherPort && !otherHost.isNull() &&
+        (otherHost.protocol() == QAbstractSocket::IPv4Protocol ||
+         otherHost.protocol() == QAbstractSocket::IPv6Protocol))
+    {
+        stream << quint16(OtherAddress);
+        encodeAddress(stream, otherHost, otherPort);
+    }
+
+    // XOR-MAPPED-ADDRESS
+    if (xorMappedPort && !xorMappedHost.isNull() &&
+        (xorMappedHost.protocol() == QAbstractSocket::IPv4Protocol ||
+         xorMappedHost.protocol() == QAbstractSocket::IPv6Protocol))
+    {
+        stream << quint16(XorMappedAddress);
+        stream << quint16(8);
+        stream << quint8(0);
+        if (xorMappedHost.protocol() == QAbstractSocket::IPv4Protocol)
+        {
+            stream << quint8(STUN_IPV4);
+            stream << quint16(xorMappedPort ^ (STUN_MAGIC >> 16));
+            stream << quint32(xorMappedHost.toIPv4Address() ^ STUN_MAGIC);
+        } else {
+            stream << quint8(STUN_IPV6);
+            stream << quint16(xorMappedPort ^ (STUN_MAGIC >> 16));
+            Q_IPV6ADDR addr = xorMappedHost.toIPv6Address();
+            QByteArray xaddr;
+            QDataStream(&xaddr, QIODevice::WriteOnly) << STUN_MAGIC;
+            xaddr += m_id;
+            for (int i = 0; i < 16; i++)
+                xaddr[i] = xaddr[i] ^ addr[i];
+            stream.writeRawData(xaddr.data(), xaddr.size());
+        }
+    }
+
+    // ERROR-CODE
+    if (errorCode)
+    {
+        const quint16 reserved = 0;
+        const quint8 errorCodeHigh = errorCode / 100;
+        const quint8 errorCodeLow = errorCode % 100;
+        const QByteArray phrase = errorPhrase.toUtf8();
+        stream << quint16(ErrorCode);
+        stream << quint16(phrase.size() + 4);
+        stream << reserved;
+        stream << errorCodeHigh;
+        stream << errorCodeLow;
+        stream.writeRawData(phrase.data(), phrase.size());
+        if (phrase.size() % 4)
+        {
+            const QByteArray padding(4 - (phrase.size() %  4), 0);
+            stream.writeRawData(padding.data(), padding.size());
+        }
+    }
+
+    // PRIORITY
+    if (priority)
+    {
+        stream << quint16(Priority);
+        stream << quint16(sizeof(priority));
+        stream << priority;
+    }
+
+    // USE-CANDIDATE
+    if (useCandidate)
+    {
+        stream << quint16(UseCandidate);
+        stream << quint16(0);
+    }
+
+    // SOFTWARE
+    if (!software.isEmpty())
+    {
+        stream << quint16(Software);
+        encodeString(stream, software);
+    }
+
+    // ICE-CONTROLLING or ICE-CONTROLLED
+    if (!iceControlling.isEmpty())
+    {
+        stream << quint16(IceControlling);
+        stream << quint16(iceControlling.size());
+        stream.writeRawData(iceControlling.data(), iceControlling.size());
+    } else if (!iceControlled.isEmpty()) {
+        stream << quint16(IceControlled);
+        stream << quint16(iceControlled.size());
+        stream.writeRawData(iceControlled.data(), iceControlled.size());
+    }
+
+    // USERNAME
+    if (!username.isEmpty())
+    {
+        stream << quint16(Username);
+        encodeString(stream, username);
+    }
+
+    // set body length
+    setBodyLength(buffer, buffer.size() - STUN_HEADER);
+
+    // MESSAGE-INTEGRITY
+    if (!password.isEmpty())
+    {
+        const QByteArray key = password.toUtf8();
+        setBodyLength(buffer, buffer.size() - STUN_HEADER + 24);
+        QByteArray integrity = generateHmacSha1(key, buffer);
+        stream << quint16(MessageIntegrity);
+        stream << quint16(integrity.size());
+        stream.writeRawData(integrity.data(), integrity.size());
+    }
+
+    // FINGERPRINT
+    setBodyLength(buffer, buffer.size() - STUN_HEADER + 8);
+    quint32 fingerprint = generateCrc32(buffer) ^ 0x5354554eL;
+    stream << quint16(Fingerprint);
+    stream << quint16(sizeof(fingerprint));
+    stream << fingerprint;
+
+    return buffer;
+}
+
+/// If the given packet looks like a STUN message, returns the message
+/// type, otherwise returns 0.
+///
+/// \param buffer
+
+quint16 QXmppStunMessage::peekType(const QByteArray &buffer)
+{
+    if (buffer.size() < STUN_HEADER)
+        return 0;
+
+    // parse STUN header
+    QDataStream stream(buffer);
+    quint16 type;
+    quint16 length;
+    quint32 cookie;
+    stream >> type;
+    stream >> length;
+    stream >> cookie;
+
+    if (cookie != STUN_MAGIC || length != buffer.size() - STUN_HEADER)
+        return 0;
+
+    return type;
+}
+ 
+void QXmppStunMessage::setBodyLength(QByteArray &buffer, qint16 length) const
+{
+    QDataStream stream(&buffer, QIODevice::WriteOnly);
+    stream.device()->seek(2);
+    stream << length;
+}
+
+QString QXmppStunMessage::toString() const
+{
+    QStringList dumpLines;
+    QString typeName;
+    switch (m_type & 0x000f)
+    {
+        case 1: typeName = "Binding"; break;
+        case 2: typeName = "Shared Secret"; break;
+        default: typeName = "Unknown"; break;
+    }
+    switch (m_type & 0x0ff0)
+    {
+        case 0x000: typeName += " Request"; break;
+        case 0x010: typeName += " Indication"; break;
+        case 0x100: typeName += " Response"; break;
+        case 0x110: typeName += " Error"; break;
+        default: break;
+    }
+    dumpLines << QString(" type %1 (%2)")
+        .arg(typeName)
+        .arg(QString::number(m_type));
+    dumpLines << QString(" id %1").arg(QString::fromAscii(m_id.toHex()));
+
+    // attributes
+    if (!username.isEmpty())
+        dumpLines << QString(" * USERNAME %1").arg(username);
+    if (errorCode)
+        dumpLines << QString(" * ERROR-CODE %1 %2")
+            .arg(QString::number(errorCode))
+            .arg(errorPhrase);
+    if (!software.isEmpty())
+        dumpLines << QString(" * SOFTWARE %1").arg(software);
+    if (mappedPort)
+        dumpLines << QString(" * MAPPED-ADDRESS %1 %2")
+            .arg(mappedHost.toString())
+            .arg(QString::number(mappedPort));
+    if (otherPort)
+        dumpLines << QString(" * OTHER-ADDRESS %1 %2")
+            .arg(otherHost.toString())
+            .arg(QString::number(otherPort));
+    if (xorMappedPort)
+        dumpLines << QString(" * XOR-MAPPED-ADDRESS %1 %2")
+            .arg(xorMappedHost.toString())
+            .arg(QString::number(xorMappedPort));
+    if (!iceControlling.isEmpty())
+        dumpLines << QString(" * ICE-CONTROLLING %1")
+            .arg(QString::fromAscii(iceControlling.toHex()));
+    if (!iceControlled.isEmpty())
+        dumpLines << QString(" * ICE-CONTROLLED %1")
+            .arg(QString::fromAscii(iceControlled.toHex()));
+
+    return dumpLines.join("\n");
+}
+
+QXmppStunSocket::Pair::Pair()
+    : checked(QIODevice::NotOpen)
+{
+    // FIXME : calculate priority
+    priority = 1862270975;
+    transaction = randomByteArray(ID_SIZE);
+}
+
+QString QXmppStunSocket::Pair::toString() const
+{
+    QString str = QString("%1 %2").arg(remote.host().toString(), QString::number(remote.port()));
+    if (!reflexive.host().isNull() && reflexive.port())
+        str += QString(" (reflexive %1 %2)").arg(reflexive.host().toString(), QString::number(reflexive.port()));
+    return str;
+}
+
+/// Constructs a new QXmppStunSocket.
+///
+
+QXmppStunSocket::QXmppStunSocket(bool iceControlling, QObject *parent)
+    : QObject(parent),
+    m_activePair(0),
+    m_iceControlling(iceControlling)
+{
+    m_localUser = generateStanzaHash(4);
+    m_localPassword = generateStanzaHash(22);
+
+    m_socket = new QUdpSocket(this);
+    connect(m_socket, SIGNAL(readyRead()), this, SLOT(readyRead()));
+    if (!m_socket->bind())
+        qWarning("QXmppStunSocket could not start listening");
+
+    m_timer = new QTimer(this);
+    m_timer->setInterval(500);
+    connect(m_timer, SIGNAL(timeout()), this, SLOT(checkCandidates())); 
+}
+
+QXmppStunSocket::~QXmppStunSocket()
+{
+    foreach (Pair *pair, m_pairs)
+        delete pair;
+}
+
+/// Returns the component id for the current socket, e.g. 1 for RTP
+/// and 2 for RTCP.
+
+int QXmppStunSocket::component() const
+{
+    return m_component;
+}
+
+/// Sets the component id for the current socket, e.g. 1 for RTP
+/// and 2 for RTCP.
+///
+/// \param component
+
+void QXmppStunSocket::setComponent(int component)
+{
+    m_component = component;
+}
+
+void QXmppStunSocket::checkCandidates()
+{
+    debug("Checking remote candidates");
+    foreach (Pair *pair, m_pairs)
+    {
+        // send a binding request
+        QXmppStunMessage message;
+        message.setId(pair->transaction);
+        message.setType(BindingRequest);
+        message.priority = pair->priority;
+        message.username = QString("%1:%2").arg(m_remoteUser, m_localUser);
+        if (m_iceControlling)
+        {
+            message.iceControlling = QByteArray(8, 0);
+            message.useCandidate = true;
+        } else {
+            message.iceControlled = QByteArray(8, 0);
+        }
+        writeStun(message, pair);
+    }
+}
+
+/// Closes the socket.
+
+void QXmppStunSocket::close()
+{
+    m_socket->close();
+    m_timer->stop();
+}
+
+/// Start ICE connectivity checks.
+
+void QXmppStunSocket::connectToHost()
+{
+    checkCandidates();
+    m_timer->start();
+}
+
+/// Returns true if ICE negotiation completed, false otherwise.
+
+bool QXmppStunSocket::isConnected() const
+{
+    return m_activePair != 0;
+}
+
+void QXmppStunSocket::debug(const QString &message, QXmppLogger::MessageType type)
+{
+    emit logMessage(type, QString("STUN(%1) %2").arg(QString::number(m_component)).arg(message));
+}
+
+/// Returns the list of local HOST CANDIDATES candidates by iterating
+/// over the available network interfaces.
+
+QList<QXmppJingleCandidate> QXmppStunSocket::localCandidates() const
+{
+    QList<QXmppJingleCandidate> candidates;
+    foreach (const QNetworkInterface &interface, QNetworkInterface::allInterfaces())
+    {
+        if (!(interface.flags() & QNetworkInterface::IsRunning) ||
+            interface.flags() & QNetworkInterface::IsLoopBack)
+            continue;
+
+        foreach (const QNetworkAddressEntry &entry, interface.addressEntries())
+        {
+            if (entry.ip().protocol() != QAbstractSocket::IPv4Protocol ||
+                entry.netmask().isNull() ||
+                entry.netmask() == QHostAddress::Broadcast)
+                continue;
+
+            QXmppJingleCandidate candidate;
+            candidate.setComponent(m_component);
+            candidate.setHost(entry.ip());
+            candidate.setId(generateStanzaHash(10));
+            candidate.setNetwork(interface.index());
+            candidate.setPort(m_socket->localPort());
+            candidate.setPriority(2130706432 - m_component);
+            candidate.setProtocol("udp");
+            candidate.setType("host");
+            candidates << candidate;
+        }
+    }
+    return candidates;
+}
+
+QString QXmppStunSocket::localUser() const
+{
+    return m_localUser;
+}
+
+void QXmppStunSocket::setLocalUser(const QString &user)
+{
+    m_localUser = user;
+}
+
+QString QXmppStunSocket::localPassword() const
+{
+    return m_localPassword;
+}
+
+void QXmppStunSocket::setLocalPassword(const QString &password)
+{
+    m_localPassword = password;
+}
+
+/// Adds a remote STUN candidate.
+
+bool QXmppStunSocket::addRemoteCandidate(const QXmppJingleCandidate &candidate)
+{
+    if (candidate.component() != m_component ||
+        candidate.type() != "host" ||
+        candidate.protocol() != "udp")
+        return false;
+
+    foreach (Pair *pair, m_pairs)
+        if (pair->remote.host() == candidate.host() &&
+            pair->remote.port() == candidate.port())
+            return false;
+
+    Pair *pair = new Pair;
+    pair->remote = candidate;
+    m_pairs << pair;
+    return true;
+}
+
+/// Adds a discovered STUN candidate.
+
+QXmppStunSocket::Pair *QXmppStunSocket::addRemoteCandidate(const QHostAddress &host, quint16 port)
+{
+    foreach (Pair *pair, m_pairs)
+        if (pair->remote.host() == host &&
+            pair->remote.port() == port)
+            return pair;
+
+    QXmppJingleCandidate candidate;
+    candidate.setHost(host);
+    candidate.setPort(port);
+    candidate.setProtocol("udp");
+    candidate.setComponent(m_component);
+
+    Pair *pair = new Pair;
+    pair->remote = candidate;
+    m_pairs << pair;
+
+    debug(QString("Added candidate %1").arg(pair->toString()));
+    return pair;
+}
+
+void QXmppStunSocket::setRemoteUser(const QString &user)
+{
+    m_remoteUser = user;
+}
+
+void QXmppStunSocket::setRemotePassword(const QString &password)
+{
+    m_remotePassword = password;
+}
+
+void QXmppStunSocket::readyRead()
+{
+    const qint64 size = m_socket->pendingDatagramSize();
+    QHostAddress remoteHost;
+    quint16 remotePort;
+    QByteArray buffer(size, 0);
+    m_socket->readDatagram(buffer.data(), buffer.size(), &remoteHost, &remotePort);
+
+    // if this is not a STUN message, emit it
+    quint16 messageType = QXmppStunMessage::peekType(buffer);
+    if (!messageType)
+    {
+        emit datagramReceived(buffer);
+        return;
+    }
+
+    // parse STUN message
+    const QString messagePassword = (messageType & 0xFF00) ? m_remotePassword : m_localPassword;
+    if (messagePassword.isEmpty())
+        return;
+    QXmppStunMessage message;
+    QStringList errors;
+    if (!message.decode(buffer, messagePassword, &errors))
+    {
+        foreach (const QString &error, errors)
+            debug(error, QXmppLogger::WarningMessage);
+        return;
+    }
+#ifdef QXMPP_DEBUG_STUN
+    debug(QString("Received from %1 port %2\n%3")
+        .arg(remoteHost.toString())
+        .arg(QString::number(remotePort))
+        .arg(message.toString()),
+        QXmppLogger::ReceivedMessage);
+#endif
+
+    if (m_activePair)
+        return;
+
+    // process message
+    Pair *pair = 0;
+    if (message.type() == BindingRequest)
+    {
+        // add remote candidate
+        pair = addRemoteCandidate(remoteHost, remotePort);
+
+        // send a binding response
+        QXmppStunMessage response;
+        response.setId(message.id());
+        response.setType(BindingResponse);
+        response.username = message.username;
+        response.xorMappedHost = pair->remote.host();
+        response.xorMappedPort = pair->remote.port();
+        writeStun(response, pair);
+
+        // update state
+        if (m_iceControlling || message.useCandidate)
+        {
+            debug(QString("ICE reverse check %1").arg(pair->toString()));
+            pair->checked |= QIODevice::ReadOnly;
+        }
+
+        if (!m_iceControlling)
+        {
+            // send a triggered connectivity test
+            QXmppStunMessage message;
+            message.setId(pair->transaction);
+            message.setType(BindingRequest);
+            message.priority = pair->priority;
+            message.username = QString("%1:%2").arg(m_remoteUser, m_localUser);
+            message.iceControlled = QByteArray(8, 0);
+            writeStun(message, pair);
+        }
+
+    } else if (message.type() == BindingResponse) {
+
+        // find the pair for this transaction
+        foreach (Pair *ptr, m_pairs)
+        {
+            if (ptr->transaction == message.id())
+            {
+                pair = ptr;
+                break;
+            }
+        }
+        if (!pair)
+        {
+            debug(QString("Unknown transaction %1").arg(QString::fromAscii(message.id().toHex())));
+            return;
+        }
+        // store reflexive address
+        pair->reflexive.setHost(message.xorMappedHost);
+        pair->reflexive.setPort(message.xorMappedPort);
+
+        // add the new remote candidate
+        addRemoteCandidate(remoteHost, remotePort);
+
+#if 0
+        // send a binding indication
+        QXmppStunMessage indication;
+        indication.setId(randomByteArray(ID_SIZE));
+        indication.setType(BindingIndication);
+        m_socket->writeStun(indication, pair);
+#endif
+        // outgoing media can flow
+        debug(QString("ICE forward check %1").arg(pair->toString()));
+        pair->checked |= QIODevice::WriteOnly;
+    }
+
+    // signal completion
+    if (pair && pair->checked == QIODevice::ReadWrite)
+    { 
+        debug(QString("ICE completed %1").arg(pair->toString()));
+        m_activePair = pair;
+        m_timer->stop();
+        emit connected();
+    }
+}
+
+/// Sends a data packet to the remote party.
+///
+/// \param datagram
+
+qint64 QXmppStunSocket::writeDatagram(const QByteArray &datagram)
+{
+    if (!m_activePair)
+        return -1;
+    return m_socket->writeDatagram(datagram, m_activePair->remote.host(), m_activePair->remote.port());
+}
+
+/// Sends a STUN packet to the remote party.
+
+qint64 QXmppStunSocket::writeStun(const QXmppStunMessage &message, QXmppStunSocket::Pair *pair)
+{
+    const QString messagePassword = (message.type() & 0xFF00) ? m_localPassword : m_remotePassword;
+#ifdef QXMPP_DEBUG_STUN
+    debug(
+        QString("Sent to %1\n%2").arg(pair->toString(), message.toString()),
+        QXmppLogger::SentMessage);
+#endif
+    return m_socket->writeDatagram(message.encode(messagePassword), pair->remote.host(), pair->remote.port());
+}
+