Add libproxy backend for QNetworkProxyFactory

It will be used on Unix systems if the required dev package is
present. (Detected by a configure compile test.)
You can configure with -no-libproxy to avoid the dependency.
It will not be used on OS X or Windows, as we already implement
the native API for getting proxies there.

Currently we use whatever PAC runner is provided by the distro
for running PAC scripts - if we want to run PAC scripts using
Qt, then we would have to implement a pacrunner plugin to libproxy.
Note that their webkit pacrunner is using javascriptcore already.

Tested using the libproxy 0.4.7 that is included in Ubuntu 12.04.
Re-tested using Ubuntu 14.04 which ships libproxy 0.4.11.

It works except when both socks and http proxies are configured in
the manual settings - in that case libproxy returns only the socks
proxy. This seems to be covered by libproxy issue 119.

[ChangeLog][QtNetwork] Introduce libproxy backend for Unix platforms,
enabled automatically if the required dev package is present

Task-number: QTBUG-26295
Change-Id: I521c0a198fcf482386ea8a189114a0077778265c
Reviewed-by: Richard J. Moore <rich@kde.org>

6 files changed, 283 insertions, 3 deletions

diff --git a/config.tests/common/libproxy/libproxy.cpp b/config.tests/common/libproxy/libproxy.cpp
new file mode 100644
index 0000000000..cd366f52ee
--- /dev/null
+++ b/config.tests/common/libproxy/libproxy.cpp
@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the config.tests of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <proxy.h>
+
+int main(int, char **)
+{
+    pxProxyFactory *factory = px_proxy_factory_new();
+    char **proxies = px_proxy_factory_get_proxies(factory, "http://qt-project.org");
+    if (proxies) {
+        for (int i = 0; proxies[i]; i++) {
+            printf("%s\n", proxies[i]);
+            free(proxies[i]);
+        }
+        free(proxies);
+    }
+    px_proxy_factory_free(factory);
+    return 0;
+}
diff --git a/config.tests/common/libproxy/libproxy.pro b/config.tests/common/libproxy/libproxy.pro
new file mode 100644
index 0000000000..51de2021ff
--- /dev/null
+++ b/config.tests/common/libproxy/libproxy.pro
@@ -0,0 +1,4 @@
+SOURCES = libproxy.cpp
+CONFIG -= qt dylib
+mac:CONFIG -= app_bundle
+LIBS += -lproxy
diff --git a/configure b/configure
index ebb2057cc6..835cb9e58f 100755
--- a/configure
+++ b/configure
@@ -681,6 +681,7 @@ CFG_GLIB=auto
 CFG_QGTKSTYLE=auto
 CFG_LARGEFILE=auto
 CFG_OPENSSL=auto
+CFG_LIBPROXY=auto
 CFG_SECURETRANSPORT=auto
 CFG_PRECOMPILE=auto
 CFG_SEPARATE_DEBUG_INFO=no
@@ -1980,6 +1981,13 @@ while [ "$#" -gt 0 ]; do
             UNKNOWN_OPT=yes
         fi
         ;;
+    libproxy)
+        if [ "$VAL" = "yes" ] || [ "$VAL" = "no" ]; then
+            CFG_LIBPROXY="$VAL"
+        else
+            UNKNOWN_OPT=yes
+        fi
+        ;;
     qml-debug)
         if [ "$VAL" = "yes" ]; then
             CFG_QML_DEBUG="yes"
@@ -2441,6 +2449,9 @@ Third Party Libraries:
  +  -openssl ............ Enable run-time OpenSSL support.
     -openssl-linked ..... Enabled linked OpenSSL support.
 
+    -no-libproxy ....... Do not compile support for libproxy
+ +  -libproxy .......... Use libproxy from the operating system.
+
     -qt-pcre ............ Use the PCRE library bundled with Qt.
  +  -system-pcre ........ Use the PCRE library from the operating system.
 
@@ -4864,6 +4875,24 @@ if [ "$CFG_DBUS" = "linked" ]; then
     fi
 fi
 
+# auto-detect libproxy support
+if [ "$CFG_LIBPROXY" != "no" ]; then
+    if compileTest common/libproxy "libproxy"; then
+        CFG_LIBPROXY=yes
+    else
+        if [ "$CFG_LIBPROXY" = "auto" ]; then
+            CFG_LIBPROXY=no
+        elif [ "$CFG_CONFIGURE_EXIT_ON_ERROR" = "yes" ]; then
+            # CFG_LIBPROXY is "yes" here
+            echo "The libproxy support cannot be enabled because libproxy was not found."
+            echo " Turn on verbose messaging (-v) to $0 to see the final report."
+            echo " If you believe this message is in error you may use the continue"
+            echo " switch (-continue) to $0 to continue."
+            exit 101
+        fi
+    fi
+fi
+
 # auto-detect Glib support
 if [ "$CFG_GLIB" != "no" ]; then
     if [ -n "$PKG_CONFIG" ]; then
@@ -6039,6 +6068,7 @@ fi
 [ "$CFG_OPENSSL" = "yes" ] && QT_CONFIG="$QT_CONFIG openssl"
 [ "$CFG_OPENSSL" = "linked" ] && QT_CONFIG="$QT_CONFIG openssl-linked"
 [ "$CFG_SECURETRANSPORT" = "yes" ] && QT_CONFIG="$QT_CONFIG ssl securetransport"
+[ "$CFG_LIBPROXY" = "yes" ] && QT_CONFIG="$QT_CONFIG libproxy"
 [ "$CFG_XCB" != "no" ] && QT_CONFIG="$QT_CONFIG xcb"
 [ "$CFG_XINPUT2" = "yes" ] && QT_CONFIG="$QT_CONFIG xinput2"
 [ "$CFG_SYSTEM_PROXIES" = "yes" ] && QT_CONFIG="$QT_CONFIG system-proxies"
@@ -6430,6 +6460,7 @@ QMakeVar set sql-plugins "$SQL_PLUGINS"
 [ "$CFG_JPEG" != "yes" ]     && QCONFIG_FLAGS="$QCONFIG_FLAGS QT_NO_IMAGEFORMAT_JPEG"
 [ "$CFG_ZLIB" != "yes" ]     && QCONFIG_FLAGS="$QCONFIG_FLAGS QT_NO_ZLIB"
 [ "$CFG_DBUS" = "no" ]      && QCONFIG_FLAGS="$QCONFIG_FLAGS QT_NO_DBUS"
+[ "$CFG_LIBPROXY" = "no" ]   && QCONFIG_FLAGS="$QCONFIG_FLAGS QT_NO_LIBPROXY"
 
 # X11/Unix/Mac only configs
 [ "$CFG_CUPS" = "no" ]       && QCONFIG_FLAGS="$QCONFIG_FLAGS QT_NO_CUPS"
@@ -6878,6 +6909,7 @@ report_support "  Networking:"
 report_support "    getaddrinfo .........." "$CFG_GETADDRINFO"
 report_support "    getifaddrs ..........." "$CFG_GETIFADDRS"
 report_support "    IPv6 ifname .........." "$CFG_IPV6IFNAME"
+report_support "    libproxy.............." "$CFG_LIBPROXY"
 report_support "    OpenSSL .............." "$CFG_OPENSSL" yes "loading libraries at run-time" linked "linked to the libraries"
 [ "$XPLATFORM_MAC" = "yes" ] && \
     report_support "    SecureTransport ......" "$CFG_SECURETRANSPORT"
diff --git a/src/network/kernel/kernel.pri b/src/network/kernel/kernel.pri
index 9b584be206..4f1527c8e9 100644
--- a/src/network/kernel/kernel.pri
+++ b/src/network/kernel/kernel.pri
@@ -54,7 +54,12 @@ mac {
 
 mac:!ios:SOURCES += kernel/qnetworkproxy_mac.cpp
 else:win32:SOURCES += kernel/qnetworkproxy_win.cpp
-else:blackberry:SOURCES += kernel/qnetworkproxy_blackberry.cpp
+else:blackberry {
+    SOURCES += kernel/qnetworkproxy_blackberry.cpp
+    LIBS_PRIVATE += -lbps
+}
+else:contains(QT_CONFIG, libproxy) {
+    SOURCES += kernel/qnetworkproxy_libproxy.cpp
+    LIBS += -lproxy
+}
 else:SOURCES += kernel/qnetworkproxy_generic.cpp
-
-blackberry: LIBS_PRIVATE += -lbps
diff --git a/src/network/kernel/qnetworkproxy_libproxy.cpp b/src/network/kernel/qnetworkproxy_libproxy.cpp
new file mode 100644
index 0000000000..f0b91d6967
--- /dev/null
+++ b/src/network/kernel/qnetworkproxy_libproxy.cpp
@@ -0,0 +1,165 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtNetwork module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qnetworkproxy.h"
+
+#ifndef QT_NO_NETWORKPROXY
+
+#include <QtCore/QByteArray>
+#include <QtCore/QUrl>
+
+#include <proxy.h>
+
+QT_BEGIN_NAMESPACE
+
+class QLibProxyWrapper
+{
+public:
+    QLibProxyWrapper()
+        : factory(px_proxy_factory_new())
+    {
+        if (!factory)
+            qWarning("libproxy initialization failed.");
+    }
+
+    ~QLibProxyWrapper()
+    {
+        px_proxy_factory_free(factory);
+    }
+
+    QList<QUrl> getProxies(const QUrl &url);
+
+private:
+    pxProxyFactory *factory;
+};
+
+Q_GLOBAL_STATIC(QLibProxyWrapper, libProxyWrapper);
+
+/*
+    Gets the list of proxies from libproxy, converted to QUrl list.
+    Thread safe, according to libproxy documentation.
+*/
+QList<QUrl> QLibProxyWrapper::getProxies(const QUrl &url)
+{
+    QList<QUrl> ret;
+
+    if (factory) {
+        char **proxies = px_proxy_factory_get_proxies(factory, url.toEncoded());
+        if (proxies) {
+            for (int i = 0; proxies[i]; i++) {
+                ret.append(QUrl::fromEncoded(proxies[i]));
+                free(proxies[i]);
+            }
+            free(proxies);
+        }
+    }
+
+    return ret;
+}
+
+QList<QNetworkProxy> QNetworkProxyFactory::systemProxyForQuery(const QNetworkProxyQuery &query)
+{
+    QList<QNetworkProxy> proxyList;
+
+    QUrl queryUrl;
+    QNetworkProxy::Capabilities requiredCapabilities(0);
+    switch (query.queryType()) {
+    //URL requests are directly supported by libproxy
+    case QNetworkProxyQuery::UrlRequest:
+        queryUrl = query.url();
+        break;
+    // fake URLs to get libproxy to tell us the SOCKS proxy
+    case QNetworkProxyQuery::TcpSocket:
+        queryUrl.setScheme(QStringLiteral("tcp"));
+        queryUrl.setHost(query.peerHostName());
+        queryUrl.setPort(query.peerPort());
+        requiredCapabilities |= QNetworkProxy::TunnelingCapability;
+        break;
+    case QNetworkProxyQuery::UdpSocket:
+        queryUrl.setScheme(QStringLiteral("udp"));
+        queryUrl.setHost(query.peerHostName());
+        queryUrl.setPort(query.peerPort());
+        requiredCapabilities |= QNetworkProxy::UdpTunnelingCapability;
+        break;
+    default:
+        proxyList.append(QNetworkProxy(QNetworkProxy::NoProxy));
+        return proxyList;
+    }
+
+    QList<QUrl> rawProxies = libProxyWrapper()->getProxies(queryUrl);
+
+    bool haveDirectConnection = false;
+    foreach (const QUrl& url, rawProxies) {
+        QNetworkProxy::ProxyType type;
+        if (url.scheme() == QStringLiteral("http")) {
+            type = QNetworkProxy::HttpProxy;
+        } else if (url.scheme() == QStringLiteral("socks")
+              || url.scheme() == QStringLiteral("socks5")) {
+            type = QNetworkProxy::Socks5Proxy;
+        } else if (url.scheme() == QStringLiteral("ftp")) {
+            type = QNetworkProxy::FtpCachingProxy;
+        } else if (url.scheme() == QStringLiteral("direct")) {
+            type = QNetworkProxy::NoProxy;
+            haveDirectConnection = true;
+        } else {
+            continue; //unsupported proxy type e.g. socks4
+        }
+
+        QNetworkProxy proxy(type,
+            url.host(QUrl::EncodeUnicode),
+            url.port(0),
+            url.userName(QUrl::FullyDecoded),
+            url.password(QUrl::FullyDecoded));
+
+        if (proxy.capabilities() & requiredCapabilities == requiredCapabilities)
+            proxyList.append(proxy);
+    }
+
+    // fallback is direct connection
+    if (proxyList.isEmpty() || !haveDirectConnection)
+        proxyList.append(QNetworkProxy(QNetworkProxy::NoProxy));
+
+    return proxyList;
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/tools/configure/configureapp.cpp b/tools/configure/configureapp.cpp
index dcbe52b1cf..7735f05989 100644
--- a/tools/configure/configureapp.cpp
+++ b/tools/configure/configureapp.cpp
@@ -269,6 +269,7 @@ Configure::Configure(int& argc, char** argv)
     dictionary[ "OPENVG" ]          = "no";
     dictionary[ "SSL" ]             = "auto";
     dictionary[ "OPENSSL" ]         = "auto";
+    dictionary[ "LIBPROXY" ]        = "auto";
     dictionary[ "DBUS" ]            = "auto";
 
     dictionary[ "STYLE_WINDOWS" ]   = "yes";
@@ -859,6 +860,10 @@ void Configure::parseCmdLine()
               dictionary[ "OPENSSL" ] = "yes";
         } else if (configCmdLine.at(i) == "-openssl-linked") {
               dictionary[ "OPENSSL" ] = "linked";
+        } else if (configCmdLine.at(i) == "-no-libproxy") {
+              dictionary[ "LIBPROXY"] = "no";
+        } else if (configCmdLine.at(i) == "-libproxy") {
+              dictionary[ "LIBPROXY" ] = "yes";
         } else if (configCmdLine.at(i) == "-no-qdbus") {
             dictionary[ "DBUS" ] = "no";
         } else if (configCmdLine.at(i) == "-qdbus") {
@@ -1973,6 +1978,8 @@ bool Configure::displayHelp()
         desc("OPENSSL", "no",    "-no-openssl",         "Do not compile support for OpenSSL.");
         desc("OPENSSL", "yes",   "-openssl",            "Enable run-time OpenSSL support.");
         desc("OPENSSL", "linked","-openssl-linked",     "Enable linked OpenSSL support.\n");
+        desc("LIBPROXY", "no",   "-no-libproxy",        "Do not compile in libproxy support.");
+        desc("LIBPROXY", "yes",  "-libproxy",           "Compile in libproxy support (for cross compilation targets).\n");
         desc("DBUS", "no",       "-no-dbus",            "Do not compile in D-Bus support.");
         desc("DBUS", "yes",      "-dbus",               "Compile in D-Bus support and load libdbus-1\ndynamically.");
         desc("DBUS", "linked",   "-dbus-linked",        "Compile in D-Bus support and link to libdbus-1.\n");
@@ -2234,6 +2241,8 @@ bool Configure::checkAvailability(const QString &part)
         available = tryCompileProject("common/avx2");
     else if (part == "OPENSSL")
         available = findFile("openssl\\ssl.h");
+    else if (part == "LIBPROXY")
+        available = dictionary.contains("XQMAKESPEC") && tryCompileProject("common/libproxy");
     else if (part == "DBUS")
         available = findFile("dbus\\dbus.h");
     else if (part == "CETEST") {
@@ -2405,6 +2414,8 @@ void Configure::autoDetection()
     }
     if (dictionary["OPENSSL"] == "auto")
         dictionary["OPENSSL"] = checkAvailability("OPENSSL") ? "yes" : "no";
+    if (dictionary["LIBPROXY"] == "auto")
+        dictionary["LIBPROXY"] = checkAvailability("LIBPROXY") ? "yes" : "no";
     if (dictionary["DBUS"] == "auto")
         dictionary["DBUS"] = checkAvailability("DBUS") ? "yes" : "no";
     if (dictionary["QML_DEBUG"] == "auto")
@@ -2841,6 +2852,9 @@ void Configure::generateOutputVars()
     else if (dictionary[ "OPENSSL" ] == "linked")
         qtConfig += "openssl-linked";
 
+    if (dictionary[ "LIBPROXY" ] == "yes")
+        qtConfig += "libproxy";
+
     if (dictionary[ "DBUS" ] == "yes")
         qtConfig += "dbus";
     else if (dictionary[ "DBUS" ] == "linked")
@@ -3695,6 +3709,7 @@ void Configure::displayConfig()
     sout << "OpenVG support.............." << dictionary[ "OPENVG" ] << endl;
     sout << "SSL support................." << dictionary[ "SSL" ] << endl;
     sout << "OpenSSL support............." << dictionary[ "OPENSSL" ] << endl;
+    sout << "libproxy support............" << dictionary[ "LIBPROXY" ] << endl;
     sout << "Qt D-Bus support............" << dictionary[ "DBUS" ] << endl;
     sout << "Qt Widgets module support..." << dictionary[ "WIDGETS" ] << endl;
     sout << "Qt GUI module support......." << dictionary[ "GUI" ] << endl;