QWebkit: downloading a page using a specific network interface

[sergico]

Hi Everybody,

I have a PC with two network interfaces; eth0 and eth1
eth1 has no IP address but it is bound to a ppp connection

eth0 Link encap:Ethernet HWaddr 00:26:18:f1:91:d1
inet addr:192.168.23.7 Bcast:192.168.23.255 Mask:255.255.255.0

ppp0 Link encap:Point-to-Point Protocol
inet addr:192.168.60.7 P-t-P:192.168.60.213 Mask:255.255.255.255

I'd like is to be able to use Qt webkit to download pages using the ppp0 and not the eth0 interface.

What I did at code level using Qt is the following:

• Retrieve the list of available network configurations
• Select the network configuration associated with the ppp0 iface
• create a QNetworkAccessManager
• set the configuration of the QNetworkAccessManager
• create a QWebPage
• set the network access manager of the webpage to the above one
• load the webpage

Unfortunately it seems that the data always exit via the eth0 iface (I monitored both ifaces with wireshark/tcpdump) The problem is not related to the routing configuration of the PC, I configured the system so that I can send packets out via the ppp0 iface.

ie. ping -c 3 -I 192.168.60.7 www.google.com is correctly routed out via the ppp0 iface

Here's a snapshot of my code:

@
QNetworkConfigurationManager* m_netConfigMngPtr;
QNetworkAccessManager* m_netAccessMngPtr;

m_netConfigMngPtr = new QNetworkConfigurationManager();
qDebug() << "network config manager capabilities" << m_netConfigMngPtr->capabilities();

QList<QNetworkConfiguration> netConfigList = m_netConfigMngPtr->allConfigurations();

QString ifaceId;
qDebug() << Q_FUNC_INFO << "Available Networck configurations:" << netConfigList.size();
foreach( QNetworkConfiguration c, netConfigList)
{
qDebug() << Q_FUNC_INFO << "network configuration:" << c.identifier() << c.name() << c.state() << c.isValid();
if (c.name() == "ppp0")
{
ifaceId = c.identifier();
}
}

QNetworkConfiguration netConf = m_netConfigMngPtr->configurationFromIdentifier(ifaceId);
qDebug() << "Net config for " << ifaceId << "(" << netConf.name() << ")" << "is valid: " << netConf.isValid();

m_netAccessMngPtr = new QNetworkAccessManager;
m_netAccessMngPtr->setConfiguration( netConf );

QWebPage* m_theWebPagePtr = new QWebPage;
m_theWebPagePtr->setNetworkAccessManager(m_netAccessMngPtr);
m_theWebPagePtr->currentFrame()->load( QUrl("http://www.google.com") );

@

I'm using Qt 4.8.1 on Linux 64bit
Any hint or suggestion on what I'm doing wrong?