peermanager.cpp Example File

network-chat/peermanager.cpp
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#include <QtNetwork> #include "client.h" #include "connection.h" #include "peermanager.h" static const qint32 BroadcastInterval = 2000; static const unsigned broadcastPort = 45000; PeerManager::PeerManager(Client *client) : QObject(client) { this->client = client; static const char *envVariables[] = { "USERNAME", "USER", "USERDOMAIN", "HOSTNAME", "DOMAINNAME" }; for (const char *varname : envVariables) { username = qEnvironmentVariable(varname); if (!username.isNull()) break; } if (username.isEmpty()) username = "unknown"; updateAddresses(); serverPort = 0; broadcastSocket.bind(QHostAddress::Any, broadcastPort, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint); connect(&broadcastSocket, SIGNAL(readyRead()), this, SLOT(readBroadcastDatagram())); broadcastTimer.setInterval(BroadcastInterval); connect(&broadcastTimer, SIGNAL(timeout()), this, SLOT(sendBroadcastDatagram())); } void PeerManager::setServerPort(int port) { serverPort = port; } QString PeerManager::userName() const { return username; } void PeerManager::startBroadcasting() { broadcastTimer.start(); } bool PeerManager::isLocalHostAddress(const QHostAddress &address) { foreach (QHostAddress localAddress, ipAddresses) { if (address.isEqual(localAddress)) return true; } return false; } void PeerManager::sendBroadcastDatagram() { QByteArray datagram; { QCborStreamWriter writer(&datagram); writer.startArray(2); writer.append(username); writer.append(serverPort); writer.endArray(); } bool validBroadcastAddresses = true; foreach (QHostAddress address, broadcastAddresses) { if (broadcastSocket.writeDatagram(datagram, address, broadcastPort) == -1) validBroadcastAddresses = false; } if (!validBroadcastAddresses) updateAddresses(); } void PeerManager::readBroadcastDatagram() { while (broadcastSocket.hasPendingDatagrams()) { QHostAddress senderIp; quint16 senderPort; QByteArray datagram; datagram.resize(broadcastSocket.pendingDatagramSize()); if (broadcastSocket.readDatagram(datagram.data(), datagram.size(), &senderIp, &senderPort) == -1) continue; int senderServerPort; { // decode the datagram QCborStreamReader reader(datagram); if (reader.lastError() != QCborError::NoError || !reader.isArray()) continue; if (!reader.isLengthKnown() || reader.length() != 2) continue; reader.enterContainer(); if (reader.lastError() != QCborError::NoError || !reader.isString()) continue; while (reader.readString().status == QCborStreamReader::Ok) { // we don't actually need the username right now } if (reader.lastError() != QCborError::NoError || !reader.isUnsignedInteger()) continue; senderServerPort = reader.toInteger(); } if (isLocalHostAddress(senderIp) && senderServerPort == serverPort) continue; if (!client->hasConnection(senderIp)) { Connection *connection = new Connection(this); emit newConnection(connection); connection->connectToHost(senderIp, senderServerPort); } } } void PeerManager::updateAddresses() { broadcastAddresses.clear(); ipAddresses.clear(); foreach (QNetworkInterface interface, QNetworkInterface::allInterfaces()) { foreach (QNetworkAddressEntry entry, interface.addressEntries()) { QHostAddress broadcastAddress = entry.broadcast(); if (broadcastAddress != QHostAddress::Null && entry.ip() != QHostAddress::LocalHost) { broadcastAddresses << broadcastAddress; ipAddresses << entry.ip(); } } } }