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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 664 insertions, 0 deletions

diff --git a/examples/network/torrent/peerwireclient.cpp b/examples/network/torrent/peerwireclient.cpp
new file mode 100644
index 0000000000..0d9580eeff
--- /dev/null
+++ b/examples/network/torrent/peerwireclient.cpp
@@ -0,0 +1,664 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
+**     the names of its contributors may be used to endorse or promote
+**     products derived from this software without specific prior written
+**     permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "peerwireclient.h"
+
+#include <QHostAddress>
+#include <QTimerEvent>
+
+static const int PendingRequestTimeout = 60 * 1000;
+static const int ClientTimeout = 120 * 1000;
+static const int ConnectTimeout = 60 * 1000;
+static const int KeepAliveInterval = 30 * 1000;
+static const int RateControlTimerDelay = 2000;
+static const int MinimalHeaderSize = 48;
+static const int FullHeaderSize = 68;
+static const char ProtocolId[] = "BitTorrent protocol";
+static const char ProtocolIdSize = 19;
+
+// Reads a 32bit unsigned int from data in network order.
+static inline quint32 fromNetworkData(const char *data)
+{
+    const unsigned char *udata = (const unsigned char *)data;
+    return (quint32(udata[0]) << 24)
+        | (quint32(udata[1]) << 16)
+        | (quint32(udata[2]) << 8)
+        | (quint32(udata[3]));
+}
+
+// Writes a 32bit unsigned int from num to data in network order.
+static inline void toNetworkData(quint32 num, char *data)
+{
+    unsigned char *udata = (unsigned char *)data;
+    udata[3] = (num & 0xff);
+    udata[2] = (num & 0xff00) >> 8;
+    udata[1] = (num & 0xff0000) >> 16;
+    udata[0] = (num & 0xff000000) >> 24;
+}
+
+// Constructs an unconnected PeerWire client and starts the connect timer.
+PeerWireClient::PeerWireClient(const QByteArray &peerId, QObject *parent)
+    : QTcpSocket(parent), pendingBlockSizes(0),
+      pwState(ChokingPeer | ChokedByPeer), receivedHandShake(false), gotPeerId(false),
+      sentHandShake(false), nextPacketLength(-1), pendingRequestTimer(0), invalidateTimeout(false),
+      keepAliveTimer(0), torrentPeer(0)
+{
+    memset(uploadSpeedData, 0, sizeof(uploadSpeedData));
+    memset(downloadSpeedData, 0, sizeof(downloadSpeedData));
+
+    transferSpeedTimer = startTimer(RateControlTimerDelay);
+    timeoutTimer = startTimer(ConnectTimeout);
+    peerIdString = peerId;
+
+    connect(this, SIGNAL(readyRead()), this, SIGNAL(readyToTransfer()));
+    connect(this, SIGNAL(connected()), this, SIGNAL(readyToTransfer()));
+
+    connect(&socket, SIGNAL(connected()),
+            this, SIGNAL(connected()));
+    connect(&socket, SIGNAL(readyRead()),
+            this, SIGNAL(readyRead()));
+    connect(&socket, SIGNAL(disconnected()),
+            this, SIGNAL(disconnected()));
+    connect(&socket, SIGNAL(error(QAbstractSocket::SocketError)),
+            this, SIGNAL(error(QAbstractSocket::SocketError)));
+    connect(&socket, SIGNAL(bytesWritten(qint64)),
+            this, SIGNAL(bytesWritten(qint64)));
+    connect(&socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
+            this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
+
+}
+
+// Registers the peer ID and SHA1 sum of the torrent, and initiates
+// the handshake.
+void PeerWireClient::initialize(const QByteArray &infoHash, int pieceCount)
+{
+    this->infoHash = infoHash;
+    peerPieces.resize(pieceCount);
+    if (!sentHandShake)
+        sendHandShake();
+}
+
+void PeerWireClient::setPeer(TorrentPeer *peer)
+{
+    torrentPeer = peer;
+}
+
+TorrentPeer *PeerWireClient::peer() const
+{
+    return torrentPeer;
+}
+
+QBitArray PeerWireClient::availablePieces() const
+{
+    return peerPieces;
+}
+
+QList<TorrentBlock> PeerWireClient::incomingBlocks() const
+{
+    return incoming;
+}
+
+// Sends a "choke" message, asking the peer to stop requesting blocks.
+void PeerWireClient::chokePeer()
+{
+    const char message[] = {0, 0, 0, 1, 0};
+    write(message, sizeof(message));
+    pwState |= ChokingPeer;
+
+    // After receiving a choke message, the peer will assume all
+    // pending requests are lost.
+    pendingBlocks.clear();
+    pendingBlockSizes = 0;
+}
+
+// Sends an "unchoke" message, allowing the peer to start/resume
+// requesting blocks.
+void PeerWireClient::unchokePeer()
+{
+    const char message[] = {0, 0, 0, 1, 1};
+    write(message, sizeof(message));
+    pwState &= ~ChokingPeer;
+
+    if (pendingRequestTimer)
+        killTimer(pendingRequestTimer);
+}
+
+// Sends a "keep-alive" message to prevent the peer from closing
+// the connection when there's no activity
+void PeerWireClient::sendKeepAlive()
+{
+    const char message[] = {0, 0, 0, 0};
+    write(message, sizeof(message));
+}
+
+// Sends an "interested" message, informing the peer that it has got
+// pieces that we'd like to download.
+void PeerWireClient::sendInterested()
+{
+    const char message[] = {0, 0, 0, 1, 2};
+    write(message, sizeof(message));
+    pwState |= InterestedInPeer;
+
+    // After telling the peer that we're interested, we expect to get
+    // unchoked within a certain timeframe; otherwise we'll drop the
+    // connection.
+    if (pendingRequestTimer)
+        killTimer(pendingRequestTimer);
+    pendingRequestTimer = startTimer(PendingRequestTimeout);
+}
+
+// Sends a "not interested" message, informing the peer that it does
+// not have any pieces that we'd like to download.
+void PeerWireClient::sendNotInterested()
+{
+    const char message[] = {0, 0, 0, 1, 3};
+    write(message, sizeof(message));
+    pwState &= ~InterestedInPeer;
+}
+
+// Sends a piece notification / a "have" message, informing the peer
+// that we have just downloaded a new piece.
+void PeerWireClient::sendPieceNotification(int piece)
+{
+    if (!sentHandShake)
+        sendHandShake();
+
+    char message[] = {0, 0, 0, 5, 4, 0, 0, 0, 0};
+    toNetworkData(piece, &message[5]);
+    write(message, sizeof(message));
+}
+
+// Sends the complete list of pieces that we have downloaded.
+void PeerWireClient::sendPieceList(const QBitArray &bitField)
+{
+    // The bitfield message may only be sent immediately after the
+    // handshaking sequence is completed, and before any other
+    // messages are sent.
+    if (!sentHandShake)
+        sendHandShake();
+
+    // Don't send the bitfield if it's all zeros.
+    if (bitField.count(true) == 0)
+	return;
+
+    int bitFieldSize = bitField.size();
+    int size = (bitFieldSize + 7) / 8;
+    QByteArray bits(size, '\0');
+    for (int i = 0; i < bitFieldSize; ++i) {
+        if (bitField.testBit(i)) {
+            quint32 byte = quint32(i) / 8;
+            quint32 bit = quint32(i) % 8;
+            bits[byte] = uchar(bits.at(byte)) | (1 << (7 - bit));
+        }
+    }
+
+    char message[] = {0, 0, 0, 1, 5};
+    toNetworkData(bits.size() + 1, &message[0]);
+    write(message, sizeof(message));
+    write(bits);
+}
+
+// Sends a request for a block.
+void PeerWireClient::requestBlock(int piece, int offset, int length)
+{
+    char message[] = {0, 0, 0, 1, 6};
+    toNetworkData(13, &message[0]);
+    write(message, sizeof(message));
+
+    char numbers[4 * 3];
+    toNetworkData(piece, &numbers[0]);
+    toNetworkData(offset, &numbers[4]);
+    toNetworkData(length, &numbers[8]);
+    write(numbers, sizeof(numbers));
+
+    incoming << TorrentBlock(piece, offset, length);
+
+    // After requesting a block, we expect the block to be sent by the
+    // other peer within a certain number of seconds. Otherwise, we
+    // drop the connection.
+    if (pendingRequestTimer)
+        killTimer(pendingRequestTimer);
+    pendingRequestTimer = startTimer(PendingRequestTimeout);
+}
+
+// Cancels a request for a block.
+void PeerWireClient::cancelRequest(int piece, int offset, int length)
+{
+    char message[] = {0, 0, 0, 1, 8};
+    toNetworkData(13, &message[0]);
+    write(message, sizeof(message));
+
+    char numbers[4 * 3];
+    toNetworkData(piece, &numbers[0]);
+    toNetworkData(offset, &numbers[4]);
+    toNetworkData(length, &numbers[8]);
+    write(numbers, sizeof(numbers));
+
+    incoming.removeAll(TorrentBlock(piece, offset, length));
+}
+
+// Sends a block to the peer.
+void PeerWireClient::sendBlock(int piece, int offset, const QByteArray &data)
+{
+    QByteArray block;
+
+    char message[] = {0, 0, 0, 1, 7};
+    toNetworkData(9 + data.size(), &message[0]);
+    block += QByteArray(message, sizeof(message));
+
+    char numbers[4 * 2];
+    toNetworkData(piece, &numbers[0]);
+    toNetworkData(offset, &numbers[4]);
+    block += QByteArray(numbers, sizeof(numbers));
+    block += data;
+
+    BlockInfo blockInfo;
+    blockInfo.pieceIndex = piece;
+    blockInfo.offset = offset;
+    blockInfo.length = data.size();
+    blockInfo.block = block;
+
+    pendingBlocks << blockInfo;
+    pendingBlockSizes += block.size();
+
+    if (pendingBlockSizes > 32 * 16384) {
+        chokePeer();
+        unchokePeer();
+        return;
+    }
+    emit readyToTransfer();
+}
+
+// Attempts to write 'bytes' bytes to the socket from the buffer.
+// This is used by RateController, which precisely controls how much
+// each client can write.
+qint64 PeerWireClient::writeToSocket(qint64 bytes)
+{
+    qint64 totalWritten = 0;
+    do {
+        if (outgoingBuffer.isEmpty() && !pendingBlocks.isEmpty()) {
+            BlockInfo block = pendingBlocks.takeFirst();
+            pendingBlockSizes -= block.length;
+            outgoingBuffer += block.block;
+        }
+        qint64 written = socket.write(outgoingBuffer.constData(),
+                                      qMin<qint64>(bytes - totalWritten, outgoingBuffer.size()));
+        if (written <= 0)
+            return totalWritten ? totalWritten : written;
+
+        totalWritten += written;
+        uploadSpeedData[0] += written;
+        outgoingBuffer.remove(0, written);
+    } while (totalWritten < bytes && (!outgoingBuffer.isEmpty() || !pendingBlocks.isEmpty()));
+
+    return totalWritten;
+}
+
+// Attempts to read at most 'bytes' bytes from the socket.
+qint64 PeerWireClient::readFromSocket(qint64 bytes)
+{
+    char buffer[1024];
+    qint64 totalRead = 0;
+    do {
+        qint64 bytesRead = socket.read(buffer, qMin<qint64>(sizeof(buffer), bytes - totalRead));
+        if (bytesRead <= 0)
+            break;
+        qint64 oldSize = incomingBuffer.size();
+        incomingBuffer.resize(oldSize + bytesRead);
+        memcpy(incomingBuffer.data() + oldSize, buffer, bytesRead);
+
+        totalRead += bytesRead;
+    } while (totalRead < bytes);
+
+    if (totalRead > 0) {
+        downloadSpeedData[0] += totalRead;
+        emit bytesReceived(totalRead);
+        processIncomingData();
+    }
+    return totalRead;
+}
+
+// Returns the average number of bytes per second this client is
+// downloading.
+qint64 PeerWireClient::downloadSpeed() const
+{
+    qint64 sum = 0;
+    for (unsigned int i = 0; i < sizeof(downloadSpeedData) / sizeof(qint64); ++i)
+        sum += downloadSpeedData[i];
+    return sum / (8 * 2);
+}
+
+// Returns the average number of bytes per second this client is
+// uploading.
+qint64 PeerWireClient::uploadSpeed() const
+{
+    qint64 sum = 0;
+    for (unsigned int i = 0; i < sizeof(uploadSpeedData) / sizeof(qint64); ++i)
+        sum += uploadSpeedData[i];
+    return sum / (8 * 2);
+}
+
+void PeerWireClient::setReadBufferSize(int size)
+{
+    socket.setReadBufferSize(size);
+}
+
+bool PeerWireClient::canTransferMore() const
+{
+    return bytesAvailable() > 0 || socket.bytesAvailable() > 0
+        || !outgoingBuffer.isEmpty() || !pendingBlocks.isEmpty();
+}
+
+void PeerWireClient::connectToHostImplementation(const QString &hostName,
+                                                 quint16 port, OpenMode openMode)
+
+{
+    setOpenMode(openMode);
+    socket.connectToHost(hostName, port, openMode);
+}
+
+void PeerWireClient::diconnectFromHostImplementation()
+{
+    socket.disconnectFromHost();
+}
+
+void PeerWireClient::timerEvent(QTimerEvent *event)
+{
+    if (event->timerId() == transferSpeedTimer) {
+        // Rotate the upload / download records.
+        for (int i = 6; i >= 0; --i) {
+            uploadSpeedData[i + 1] = uploadSpeedData[i];
+            downloadSpeedData[i + 1] = downloadSpeedData[i];
+        }
+        uploadSpeedData[0] = 0;
+        downloadSpeedData[0] = 0;
+    } else if (event->timerId() == timeoutTimer) {
+        // Disconnect if we timed out; otherwise the timeout is
+        // restarted.
+        if (invalidateTimeout) {
+            invalidateTimeout = false;
+        } else {
+            abort();
+            emit infoHashReceived(QByteArray());
+        }
+    } else if (event->timerId() == pendingRequestTimer) {
+        abort();
+    } else if (event->timerId() == keepAliveTimer) {
+        sendKeepAlive();
+    }
+    QTcpSocket::timerEvent(event);
+}
+
+// Sends the handshake to the peer.
+void PeerWireClient::sendHandShake()
+{
+    sentHandShake = true;
+
+    // Restart the timeout
+    if (timeoutTimer)
+        killTimer(timeoutTimer);
+    timeoutTimer = startTimer(ClientTimeout);
+
+    // Write the 68 byte PeerWire handshake.
+    write(&ProtocolIdSize, 1);
+    write(ProtocolId, ProtocolIdSize);
+    write(QByteArray(8, '\0'));
+    write(infoHash);
+    write(peerIdString);
+}
+
+void PeerWireClient::processIncomingData()
+{
+    invalidateTimeout = true;
+    if (!receivedHandShake) {
+        // Check that we received enough data
+        if (bytesAvailable() < MinimalHeaderSize)
+            return;
+
+        // Sanity check the protocol ID
+        QByteArray id = read(ProtocolIdSize + 1);
+        if (id.at(0) != ProtocolIdSize || !id.mid(1).startsWith(ProtocolId)) {
+            abort();
+            return;
+        }
+
+        // Discard 8 reserved bytes, then read the info hash and peer ID
+        (void) read(8);
+
+        // Read infoHash
+        QByteArray peerInfoHash = read(20);
+        if (!infoHash.isEmpty() && peerInfoHash != infoHash) {
+            abort();
+            return;
+        }
+
+        emit infoHashReceived(peerInfoHash);
+        if (infoHash.isEmpty()) {
+            abort();
+            return;
+        }
+
+        // Send handshake
+        if (!sentHandShake)
+            sendHandShake();
+        receivedHandShake = true;
+    }
+
+    // Handle delayed peer id arrival
+    if (!gotPeerId) {
+        if (bytesAvailable() < 20)
+            return;
+        gotPeerId = true;
+        if (read(20) == peerIdString) {
+            // We connected to ourself
+            abort();
+            return;
+        }
+    }
+
+    // Initialize keep-alive timer
+    if (!keepAliveTimer)
+        keepAliveTimer = startTimer(KeepAliveInterval);
+
+    do {
+        // Find the packet length
+        if (nextPacketLength == -1) {
+            if (bytesAvailable() < 4)
+                return;
+
+            char tmp[4];
+            read(tmp, sizeof(tmp));
+            nextPacketLength = fromNetworkData(tmp);
+
+            if (nextPacketLength < 0 || nextPacketLength > 200000) {
+                // Prevent DoS
+                abort();
+                return;
+            }
+        }
+
+        // KeepAlive
+        if (nextPacketLength == 0) {
+            nextPacketLength = -1;
+            continue;
+        }
+
+        // Wait with parsing until the whole packet has been received
+        if (bytesAvailable() < nextPacketLength)
+            return;
+
+        // Read the packet
+        QByteArray packet = read(nextPacketLength);
+        if (packet.size() != nextPacketLength) {
+            abort();
+            return;
+        }
+
+        switch (packet.at(0)) {
+        case ChokePacket:
+            // We have been choked.
+            pwState |= ChokedByPeer;
+            incoming.clear();
+            if (pendingRequestTimer)
+                killTimer(pendingRequestTimer);
+            emit choked();
+            break;
+        case UnchokePacket:
+            // We have been unchoked.
+            pwState &= ~ChokedByPeer;
+            emit unchoked();
+            break;
+        case InterestedPacket:
+            // The peer is interested in downloading.
+            pwState |= PeerIsInterested;
+            emit interested();
+            break;
+        case NotInterestedPacket:
+            // The peer is not interested in downloading.
+            pwState &= ~PeerIsInterested;
+            emit notInterested();
+            break;
+        case HavePacket: {
+            // The peer has a new piece available.
+            quint32 index = fromNetworkData(&packet.data()[1]);
+            if (index < quint32(peerPieces.size())) {
+                // Only accept indexes within the valid range.
+                peerPieces.setBit(int(index));
+            }
+            emit piecesAvailable(availablePieces());
+            break;
+        }
+        case BitFieldPacket:
+            // The peer has the following pieces available.
+            for (int i = 1; i < packet.size(); ++i) {
+                for (int bit = 0; bit < 8; ++bit) {
+                    if (packet.at(i) & (1 << (7 - bit))) {
+                        int bitIndex = int(((i - 1) * 8) + bit);
+                        if (bitIndex >= 0 && bitIndex < peerPieces.size()) {
+                            // Occasionally, broken clients claim to have
+                            // pieces whose index is outside the valid range.
+                            // The most common mistake is the index == size
+                            // case.
+                            peerPieces.setBit(bitIndex);
+                        }
+                    }
+                }
+            }
+            emit piecesAvailable(availablePieces());
+            break;
+        case RequestPacket: {
+            // The peer requests a block.
+            quint32 index = fromNetworkData(&packet.data()[1]);
+            quint32 begin = fromNetworkData(&packet.data()[5]);
+            quint32 length = fromNetworkData(&packet.data()[9]);
+            emit blockRequested(int(index), int(begin), int(length));
+            break;
+        }
+        case PiecePacket: {
+            int index = int(fromNetworkData(&packet.data()[1]));
+            int begin = int(fromNetworkData(&packet.data()[5]));
+
+            incoming.removeAll(TorrentBlock(index, begin, packet.size() - 9));
+
+            // The peer sends a block.
+            emit blockReceived(index, begin, packet.mid(9));
+
+            // Kill the pending block timer.
+            if (pendingRequestTimer) {
+                killTimer(pendingRequestTimer);
+                pendingRequestTimer = 0;
+            }
+            break;
+        }
+        case CancelPacket: {
+            // The peer cancels a block request.
+            quint32 index = fromNetworkData(&packet.data()[1]);
+            quint32 begin = fromNetworkData(&packet.data()[5]);
+            quint32 length = fromNetworkData(&packet.data()[9]);
+            for (int i = 0; i < pendingBlocks.size(); ++i) {
+                const BlockInfo &blockInfo = pendingBlocks.at(i);
+                if (blockInfo.pieceIndex == int(index)
+                    && blockInfo.offset == int(begin)
+                    && blockInfo.length == int(length)) {
+                    pendingBlocks.removeAt(i);
+                    break;
+                }
+            }
+            break;
+        }
+        default:
+            // Unsupported packet type; just ignore it.
+            break;
+        }
+        nextPacketLength = -1;
+    } while (bytesAvailable() > 0);
+}
+
+void PeerWireClient::socketStateChanged(QAbstractSocket::SocketState state)
+{
+    setLocalAddress(socket.localAddress());
+    setLocalPort(socket.localPort());
+    setPeerName(socket.peerName());
+    setPeerAddress(socket.peerAddress());
+    setPeerPort(socket.peerPort());
+    setSocketState(state);
+}
+
+qint64 PeerWireClient::readData(char *data, qint64 size)
+{
+    int n = qMin<int>(size, incomingBuffer.size());
+    memcpy(data, incomingBuffer.constData(), n);
+    incomingBuffer.remove(0, n);
+    return n;
+}
+
+qint64 PeerWireClient::readLineData(char *data, qint64 maxlen)
+{
+    return QIODevice::readLineData(data, maxlen);
+}
+
+qint64 PeerWireClient::writeData(const char *data, qint64 size)
+{
+    int oldSize = outgoingBuffer.size();
+    outgoingBuffer.resize(oldSize + size);
+    memcpy(outgoingBuffer.data() + oldSize, data, size);
+    emit readyToTransfer();
+    return size;
+}