Russian Qt Forum

QT       += core network

QT       -= gui

TARGET = proxy

CONFIG   += console
CONFIG   -= app_bundle

TEMPLATE = app


SOURCES += main.cpp \
    proxy.cpp

HEADERS += \
    proxy.h

#include <QCoreApplication>
#include "proxy.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    Proxy proxy;

    return a.exec();
}

#pragma once

#include <QObject>

class QTcpSocket;
class QTcpServer;

class Proxy : public QObject
{
    Q_OBJECT
public:
    explicit Proxy(QObject *parent = 0);
private:
    QTcpServer *srv;
    QTcpSocket *outSocket;
    QTcpSocket *inSocket;
    QByteArray inData;
    QByteArray outData;
    QString host;
    QString getHost(const QByteArray &data);
private slots:
    void slotSrvNewConnection();
    void slotInSocketRead();
    void slotOutSocketRead();
    void slotOutSocketConnected();
};

#include <QDebug>
#include <QTcpSocket>
#include <QTcpServer>
#include <QRegExp>
#include "proxy.h"

Proxy::Proxy(QObject *parent)
{
    srv = new QTcpServer;

    outSocket = new QTcpSocket;

    connect(srv, SIGNAL(newConnection()), SLOT(slotSrvNewConnection()));
    connect(outSocket, SIGNAL(readyRead()), SLOT(slotOutSocketRead()));
    connect(outSocket, SIGNAL(connected()), SLOT(slotOutSocketConnected()));

    srv->listen(QHostAddress::LocalHost, 8080);
}

QString Proxy::getHost(const QByteArray &data)
{
    QString str = data.data();

    QRegExp rx("host: ([A-Za-z0-9\\.\\-]+)");

    if (rx.indexIn(str.toLower()) != 1)
        host = rx.cap(1);

    return host;
}

void Proxy::slotSrvNewConnection()
{
    qDebug() << "-------------------------------";
    qDebug() << Q_FUNC_INFO;

    inSocket = srv->nextPendingConnection();

    connect(inSocket, SIGNAL(readyRead()), SLOT(slotInSocketRead()));
}

void Proxy::slotOutSocketConnected()
{
    qDebug() << "-------------------------------";
    qDebug() << host << Q_FUNC_INFO;

    outSocket->write(outData);
}

void Proxy::slotOutSocketRead()
{
    qDebug() << "-------------------------------";
    qDebug() << host << Q_FUNC_INFO;

    inData = outSocket->readAll();
    inSocket->write(inData);
}

void Proxy::slotInSocketRead()
{
    qDebug() << "-------------------------------";
    qDebug() << Q_FUNC_INFO;

    outData = inSocket->readAll();

    if (outSocket->state() != QAbstractSocket::UnconnectedState){
        outSocket->disconnectFromHost();
    }

    outSocket->connectToHost(getHost(outData), 80);
}