Add HTTP & SOCKS5 proxy support (#4321)

This can be configured using the `CHATTERINO2_PROXY_URL` environment variable.
The behaviour is similar to curl's CURLOPT_PROXY

src/providers/NetworkConfigurationProvider.cpp

@@ -0,0 +1,76 @@
+#include "providers/NetworkConfigurationProvider.hpp"
+
+#include "common/Env.hpp"
+#include "common/QLogging.hpp"
+
+#include <QNetworkProxy>
+#include <QSslConfiguration>
+#include <QUrl>
+
+namespace {
+/**
+ * Creates a QNetworkProxy from a given URL.
+ *
+ * Creates an HTTP proxy by default, a Socks5 will be created if the scheme is 'socks5'.
+ */
+QNetworkProxy createProxyFromUrl(const QUrl &url)
+{
+    QNetworkProxy proxy;
+    proxy.setHostName(url.host(QUrl::FullyEncoded));
+    proxy.setUser(url.userName(QUrl::FullyEncoded));
+    proxy.setPassword(url.password(QUrl::FullyEncoded));
+    proxy.setPort(url.port(1080));
+
+    if (url.scheme().compare(QStringLiteral("socks5"), Qt::CaseInsensitive) ==
+        0)
+    {
+        proxy.setType(QNetworkProxy::Socks5Proxy);
+    }
+    else
+    {
+        proxy.setType(QNetworkProxy::HttpProxy);
+        if (!proxy.user().isEmpty() || !proxy.password().isEmpty())
+        {
+            // for some reason, Qt doesn't set the Proxy-Authorization header
+            const auto auth = proxy.user() + ":" + proxy.password();
+            const auto base64 = auth.toUtf8().toBase64();
+            proxy.setRawHeader("Proxy-Authorization",
+                               QByteArray("Basic ").append(base64));
+        }
+    }
+
+    return proxy;
+}
+
+/**
+ * Attempts to apply the proxy specified by `url` as the application proxy.
+ */
+void applyProxy(const QString &url)
+{
+    auto proxyUrl = QUrl(url);
+    if (!proxyUrl.isValid() || proxyUrl.isEmpty())
+    {
+        qCDebug(chatterinoNetwork)
+            << "Invalid or empty proxy url: " << proxyUrl;
+        return;
+    }
+
+    const auto proxy = createProxyFromUrl(proxyUrl);
+
+    QNetworkProxy::setApplicationProxy(proxy);
+    qCDebug(chatterinoNetwork) << "Set application proxy to" << proxy;
+}
+
+}  // namespace
+
+namespace chatterino {
+
+void NetworkConfigurationProvider::applyFromEnv(const Env &env)
+{
+    if (env.proxyUrl)
+    {
+        applyProxy(env.proxyUrl.get());
+    }
+}
+
+}  // namespace chatterino

src/providers/NetworkConfigurationProvider.hpp

@@ -0,0 +1,61 @@
+#pragma once
+
+#include "common/QLogging.hpp"
+
+#include <QNetworkProxy>
+#include <websocketpp/connection.hpp>
+
+#include <string>
+
+namespace chatterino {
+
+class Env;
+
+/** This class manipulates the global network configuration (e.g. proxies). */
+class NetworkConfigurationProvider
+{
+public:
+    /** This class should never be instantiated. */
+    NetworkConfigurationProvider() = delete;
+
+    /**
+     * Applies the configuration requested from the environment variables.
+     *
+     * Currently a proxy is applied if configured.
+     */
+    static void applyFromEnv(const Env &env);
+
+    template <class C>
+    static void applyToWebSocket(
+        const std::shared_ptr<websocketpp::connection<C>> &connection)
+    {
+        const auto applicationProxy = QNetworkProxy::applicationProxy();
+        if (applicationProxy.type() != QNetworkProxy::HttpProxy)
+        {
+            return;
+        }
+        std::string url = "http://";
+        url += applicationProxy.hostName().toStdString();
+        url += ":";
+        url += std::to_string(applicationProxy.port());
+        websocketpp::lib::error_code ec;
+        connection->set_proxy(url, ec);
+        if (ec)
+        {
+            qCDebug(chatterinoNetwork)
+                << "Couldn't set websocket proxy:" << ec.value();
+            return;
+        }
+
+        connection->set_proxy_basic_auth(
+            applicationProxy.user().toStdString(),
+            applicationProxy.password().toStdString(), ec);
+        if (ec)
+        {
+            qCDebug(chatterinoNetwork)
+                << "Couldn't set websocket proxy auth:" << ec.value();
+        }
+    }
+};
+
+}  // namespace chatterino

src/providers/liveupdates/BasicPubSubManager.hpp

@@ -4,6 +4,7 @@
 #include "common/Version.hpp"
 #include "providers/liveupdates/BasicPubSubClient.hpp"
 #include "providers/liveupdates/BasicPubSubWebsocket.hpp"
+#include "providers/NetworkConfigurationProvider.hpp"
 #include "providers/twitch/PubSubHelpers.hpp"
 #include "util/DebugCount.hpp"
 #include "util/ExponentialBackoff.hpp"
@@ -336,6 +337,8 @@ private:
             return;
         }
 
+        NetworkConfigurationProvider::applyToWebSocket(con);
+
         this->websocketClient_.connect(con);
     }
 

src/providers/twitch/PubSubManager.cpp

@@ -1,6 +1,7 @@
 #include "providers/twitch/PubSubManager.hpp"
 
 #include "common/QLogging.hpp"
+#include "providers/NetworkConfigurationProvider.hpp"
 #include "providers/twitch/PubSubActions.hpp"
 #include "providers/twitch/PubSubClient.hpp"
 #include "providers/twitch/PubSubHelpers.hpp"
@@ -514,6 +515,8 @@ void PubSub::addClient()
         return;
     }
 
+    NetworkConfigurationProvider::applyToWebSocket(con);
+
     this->websocketClient.connect(con);
 }