Ladybird+Userland: Remove use of unnecessary fd passing socket concept

Now that LibIPC is using SCM_RIGHTS properly, we can go back to only
having one socket laying around when needing to transfer fds to peers.

Ladybird/AppKit/Application/Application.h

@@ -8,8 +8,8 @@
 
 #include <AK/Error.h>
 #include <AK/Vector.h>
+#include <LibIPC/Forward.h>
 #include <LibWebView/Forward.h>
-#include <LibWebView/SocketPair.h>
 
 #import <System/Cocoa.h>
 
@@ -23,6 +23,6 @@ class WebViewBridge;
 
 - (ErrorOr<void>)launchRequestServer:(Vector<ByteString> const&)certificates;
 - (ErrorOr<NonnullRefPtr<WebView::WebContentClient>>)launchWebContent:(Ladybird::WebViewBridge&)web_view_bridge;
-- (ErrorOr<WebView::SocketPair>)launchWebWorker;
+- (ErrorOr<IPC::File>)launchWebWorker;
 
 @end

Ladybird/AppKit/Application/Application.mm

@@ -45,7 +45,7 @@
     return m_application_bridge->launch_web_content(web_view_bridge);
 }
 
-- (ErrorOr<WebView::SocketPair>)launchWebWorker
+- (ErrorOr<IPC::File>)launchWebWorker
 {
     return m_application_bridge->launch_web_worker();
 }

Ladybird/AppKit/Application/ApplicationBridge.cpp

@@ -40,20 +40,20 @@ ErrorOr<void> ApplicationBridge::launch_request_server(Vector<ByteString> const&
 ErrorOr<NonnullRefPtr<WebView::WebContentClient>> ApplicationBridge::launch_web_content(WebViewBridge& web_view_bridge)
 {
     // FIXME: Fail to open the tab, rather than crashing the whole application if this fails
-    auto request_server_sockets = TRY(connect_new_request_server_client(*m_impl->request_server_client));
+    auto request_server_socket = TRY(connect_new_request_server_client(*m_impl->request_server_client));
 
     auto web_content_paths = TRY(get_paths_for_helper_process("WebContent"sv));
-    auto web_content = TRY(launch_web_content_process(web_view_bridge, web_content_paths, web_view_bridge.web_content_options(), move(request_server_sockets)));
+    auto web_content = TRY(launch_web_content_process(web_view_bridge, web_content_paths, web_view_bridge.web_content_options(), move(request_server_socket)));
 
     return web_content;
 }
 
-ErrorOr<WebView::SocketPair> ApplicationBridge::launch_web_worker()
+ErrorOr<IPC::File> ApplicationBridge::launch_web_worker()
 {
     auto web_worker_paths = TRY(get_paths_for_helper_process("WebWorker"sv));
     auto worker_client = TRY(launch_web_worker_process(web_worker_paths, *m_impl->request_server_client));
 
-    return worker_client->dup_sockets();
+    return worker_client->dup_socket();
 }
 
 }

Ladybird/AppKit/Application/ApplicationBridge.h

@@ -8,8 +8,8 @@
 
 #include <AK/NonnullOwnPtr.h>
 #include <AK/Vector.h>
+#include <LibIPC/Forward.h>
 #include <LibWebView/Forward.h>
-#include <LibWebView/SocketPair.h>
 
 namespace Ladybird {
 
@@ -23,7 +23,7 @@ public:
 
     ErrorOr<void> launch_request_server(Vector<ByteString> const& certificates);
     ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content(WebViewBridge&);
-    ErrorOr<WebView::SocketPair> launch_web_worker();
+    ErrorOr<IPC::File> launch_web_worker();
 
 private:
     NonnullOwnPtr<ApplicationBridgeImpl> m_impl;

Ladybird/HelperProcess.cpp

@@ -13,7 +13,7 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
     WebView::ViewImplementation& view,
     ReadonlySpan<ByteString> candidate_web_content_paths,
     Ladybird::WebContentOptions const& web_content_options,
-    Optional<WebView::SocketPair> request_server_sockets)
+    Optional<IPC::File> request_server_socket)
 {
     int socket_fds[2] {};
     TRY(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, socket_fds));
@@ -21,22 +21,13 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
     int ui_fd = socket_fds[0];
     int wc_fd = socket_fds[1];
 
-    int fd_passing_socket_fds[2] {};
-    TRY(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, fd_passing_socket_fds));
-
-    int ui_fd_passing_fd = fd_passing_socket_fds[0];
-    int wc_fd_passing_fd = fd_passing_socket_fds[1];
-
     auto child_pid = TRY(Core::System::fork());
     if (child_pid == 0) {
-        TRY(Core::System::close(ui_fd_passing_fd));
         TRY(Core::System::close(ui_fd));
 
         auto takeover_string = TRY(String::formatted("WebContent:{}", wc_fd));
         TRY(Core::Environment::set("SOCKET_TAKEOVER"sv, takeover_string, Core::Environment::Overwrite::Yes));
 
-        auto webcontent_fd_passing_socket_string = TRY(String::number(wc_fd_passing_fd));
-
         ErrorOr<void> result;
         for (auto const& path : candidate_web_content_paths) {
             constexpr auto callgrind_prefix_length = 3;
@@ -53,8 +44,6 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
                 web_content_options.command_line,
                 "--executable-path"sv,
                 web_content_options.executable_path,
-                "--webcontent-fd-passing-socket"sv,
-                webcontent_fd_passing_socket_string
             };
             if (web_content_options.enable_callgrind_profiling == Ladybird::EnableCallgrindProfiling::No)
                 arguments.remove(0, callgrind_prefix_length);
@@ -74,14 +63,11 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
                 arguments.append("--mach-server-name"sv);
                 arguments.append(server.value());
             }
-            Vector<String> fd_strings;
-            if (request_server_sockets.has_value()) {
+            String fd_string;
+            if (request_server_socket.has_value()) {
                 arguments.append("--request-server-socket"sv);
-                fd_strings.append(MUST(String::number(request_server_sockets->socket.fd())));
-                arguments.append(fd_strings.last());
-                arguments.append("--request-server-fd-passing-socket"sv);
-                fd_strings.append(MUST(String::number(request_server_sockets->fd_passing_socket.fd())));
-                arguments.append(fd_strings.last());
+                fd_string = MUST(String::number(request_server_socket->fd()));
+                arguments.append(fd_string.bytes_as_string_view());
             }
 
             result = Core::System::exec(arguments[0], arguments.span(), Core::System::SearchInPath::Yes);
@@ -94,14 +80,12 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
         VERIFY_NOT_REACHED();
     }
 
-    TRY(Core::System::close(wc_fd_passing_fd));
     TRY(Core::System::close(wc_fd));
 
     auto socket = TRY(Core::LocalSocket::adopt_fd(ui_fd));
     TRY(socket->set_blocking(true));
 
     auto new_client = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) WebView::WebContentClient(move(socket), view)));
-    new_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(ui_fd_passing_fd)));
 
     if (web_content_options.enable_callgrind_profiling == Ladybird::EnableCallgrindProfiling::Yes) {
         dbgln();
@@ -122,22 +106,13 @@ ErrorOr<NonnullRefPtr<Client>> launch_generic_server_process(ReadonlySpan<ByteSt
     int ui_fd = socket_fds[0];
     int server_fd = socket_fds[1];
 
-    int fd_passing_socket_fds[2] {};
-    TRY(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, fd_passing_socket_fds));
-
-    int ui_fd_passing_fd = fd_passing_socket_fds[0];
-    int server_fd_passing_fd = fd_passing_socket_fds[1];
-
     auto child_pid = TRY(Core::System::fork());
     if (child_pid == 0) {
         TRY(Core::System::close(ui_fd));
-        TRY(Core::System::close(ui_fd_passing_fd));
 
         auto takeover_string = TRY(String::formatted("{}:{}", server_name, server_fd));
         TRY(Core::Environment::set("SOCKET_TAKEOVER"sv, takeover_string, Core::Environment::Overwrite::Yes));
 
-        auto fd_passing_socket_string = TRY(String::number(server_fd_passing_fd));
-
         ErrorOr<void> result;
         for (auto const& path : candidate_server_paths) {
 
@@ -146,8 +121,6 @@ ErrorOr<NonnullRefPtr<Client>> launch_generic_server_process(ReadonlySpan<ByteSt
 
             auto arguments = Vector<StringView> {
                 path.view(),
-                "--fd-passing-socket"sv,
-                fd_passing_socket_string,
             };
 
             if (!extra_arguments.is_empty())
@@ -164,13 +137,11 @@ ErrorOr<NonnullRefPtr<Client>> launch_generic_server_process(ReadonlySpan<ByteSt
     }
 
     TRY(Core::System::close(server_fd));
-    TRY(Core::System::close(server_fd_passing_fd));
 
     auto socket = TRY(Core::LocalSocket::adopt_fd(ui_fd));
     TRY(socket->set_blocking(true));
 
     auto new_client = TRY(try_make_ref_counted<Client>(move(socket)));
-    new_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(ui_fd_passing_fd)));
 
     WebView::ProcessManager::the().add_process(WebView::process_type_from_name(server_name), child_pid);
 
@@ -184,17 +155,13 @@ ErrorOr<NonnullRefPtr<ImageDecoderClient::Client>> launch_image_decoder_process(
 
 ErrorOr<NonnullRefPtr<Web::HTML::WebWorkerClient>> launch_web_worker_process(ReadonlySpan<ByteString> candidate_web_worker_paths, NonnullRefPtr<Protocol::RequestClient> request_client)
 {
-    auto request_server_sockets = TRY(connect_new_request_server_client(move(request_client)));
+    auto socket = TRY(connect_new_request_server_client(move(request_client)));
 
     Vector<StringView> arguments;
-    Vector<String> fd_strings;
+    String fd_string = MUST(String::number(socket.fd()));
 
     arguments.append("--request-server-socket"sv);
-    fd_strings.append(MUST(String::number(request_server_sockets.socket.fd())));
-    arguments.append(fd_strings.last());
-    arguments.append("--request-server-fd-passing-socket"sv);
-    fd_strings.append(MUST(String::number(request_server_sockets.fd_passing_socket.fd())));
-    arguments.append(fd_strings.last());
+    arguments.append(fd_string.bytes_as_string_view());
 
     return launch_generic_server_process<Web::HTML::WebWorkerClient>(candidate_web_worker_paths, "WebWorker"sv, move(arguments));
 }
@@ -215,23 +182,21 @@ ErrorOr<NonnullRefPtr<Protocol::RequestClient>> launch_request_server_process(Re
     return launch_generic_server_process<Protocol::RequestClient>(candidate_request_server_paths, "RequestServer"sv, move(arguments));
 }
 
-ErrorOr<WebView::SocketPair> connect_new_request_server_client(Protocol::RequestClient& client)
+ErrorOr<IPC::File> connect_new_request_server_client(Protocol::RequestClient& client)
 {
-    auto new_sockets = client.send_sync_but_allow_failure<Messages::RequestServer::ConnectNewClient>();
-    if (!new_sockets)
+    auto new_socket = client.send_sync_but_allow_failure<Messages::RequestServer::ConnectNewClient>();
+    if (!new_socket)
         return Error::from_string_literal("Failed to connect to RequestServer");
 
-    auto socket = new_sockets->take_client_socket();
-    auto fd_passing_socket = new_sockets->take_client_fd_passing_socket();
+    auto socket = new_socket->take_client_socket();
 
     // FIXME: IPC::Files transferred over the wire are always set O_CLOEXEC during decoding.
     //        Perhaps we should add an option to IPC::File to allow the receiver to decide whether to
     //        make it O_CLOEXEC or not. Or an attribute in the .ipc file?
-    for (auto fd : { socket.fd(), fd_passing_socket.fd() }) {
-        auto fd_flags = MUST(Core::System::fcntl(fd, F_GETFD));
-        fd_flags &= ~FD_CLOEXEC;
-        MUST(Core::System::fcntl(fd, F_SETFD, fd_flags));
-    }
+    auto fd = socket.fd();
+    auto fd_flags = MUST(Core::System::fcntl(fd, F_GETFD));
+    fd_flags &= ~FD_CLOEXEC;
+    MUST(Core::System::fcntl(fd, F_SETFD, fd_flags));
 
-    return WebView::SocketPair { move(socket), move(fd_passing_socket) };
+    return socket;
 }

Ladybird/HelperProcess.h

@@ -14,7 +14,6 @@
 #include <LibImageDecoderClient/Client.h>
 #include <LibProtocol/RequestClient.h>
 #include <LibWeb/Worker/WebWorkerClient.h>
-#include <LibWebView/SocketPair.h>
 #include <LibWebView/ViewImplementation.h>
 #include <LibWebView/WebContentClient.h>
 
@@ -22,10 +21,10 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(
     WebView::ViewImplementation& view,
     ReadonlySpan<ByteString> candidate_web_content_paths,
     Ladybird::WebContentOptions const&,
-    Optional<WebView::SocketPair> request_server_sockets = {});
+    Optional<IPC::File> request_server_socket = {});
 
 ErrorOr<NonnullRefPtr<ImageDecoderClient::Client>> launch_image_decoder_process(ReadonlySpan<ByteString> candidate_image_decoder_paths);
 ErrorOr<NonnullRefPtr<Web::HTML::WebWorkerClient>> launch_web_worker_process(ReadonlySpan<ByteString> candidate_web_worker_paths, NonnullRefPtr<Protocol::RequestClient>);
 ErrorOr<NonnullRefPtr<Protocol::RequestClient>> launch_request_server_process(ReadonlySpan<ByteString> candidate_request_server_paths, StringView serenity_resource_root, Vector<ByteString> const& certificates);
 
-ErrorOr<WebView::SocketPair> connect_new_request_server_client(Protocol::RequestClient&);
+ErrorOr<IPC::File> connect_new_request_server_client(Protocol::RequestClient&);

Ladybird/ImageDecoder/main.cpp

@@ -12,24 +12,13 @@
 #include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 
-ErrorOr<int> serenity_main(Main::Arguments arguments)
+ErrorOr<int> serenity_main(Main::Arguments)
 {
     AK::set_rich_debug_enabled(true);
 
-    int fd_passing_socket { -1 };
-    StringView serenity_resource_root;
-
-    Core::ArgsParser args_parser;
-    args_parser.add_option(fd_passing_socket, "File descriptor of the fd passing socket", "fd-passing-socket", 'c', "fd-passing-socket");
-    args_parser.add_option(serenity_resource_root, "Absolute path to directory for serenity resources", "serenity-resource-root", 'r', "serenity-resource-root");
-    args_parser.parse(arguments);
-
     Core::EventLoop event_loop;
 
     auto client = TRY(IPC::take_over_accepted_client_from_system_server<ImageDecoder::ConnectionFromClient>());
-    client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(fd_passing_socket)));
-
-    auto result = event_loop.exec();
 
-    return result;
+    return event_loop.exec();
 }

Ladybird/Qt/WebContentView.cpp

@@ -29,7 +29,6 @@
 #include <LibGfx/SystemTheme.h>
 #include <LibWeb/Crypto/Crypto.h>
 #include <LibWeb/Worker/WebWorkerClient.h>
-#include <LibWebView/SocketPair.h>
 #include <LibWebView/WebContentClient.h>
 #include <QApplication>
 #include <QCursor>
@@ -125,7 +124,7 @@ WebContentView::WebContentView(QWidget* window, WebContentOptions const& web_con
     on_request_worker_agent = []() {
         auto& request_server_client = static_cast<Ladybird::Application*>(QApplication::instance())->request_server_client;
         auto worker_client = MUST(launch_web_worker_process(MUST(get_paths_for_helper_process("WebWorker"sv)), *request_server_client));
-        return worker_client->dup_sockets();
+        return worker_client->dup_socket();
     };
 }
 
@@ -534,17 +533,17 @@ void WebContentView::initialize_client(WebView::ViewImplementation::CreateNewCli
     if (create_new_client == CreateNewClient::Yes) {
         m_client_state = {};
 
-        Optional<WebView::SocketPair> request_server_sockets;
+        Optional<IPC::File> request_server_socket;
         if (m_web_content_options.use_lagom_networking == UseLagomNetworking::Yes) {
             auto& protocol = static_cast<Ladybird::Application*>(QApplication::instance())->request_server_client;
 
             // FIXME: Fail to open the tab, rather than crashing the whole application if this fails
-            auto sockets = connect_new_request_server_client(*protocol).release_value_but_fixme_should_propagate_errors();
-            request_server_sockets = AK::move(sockets);
+            auto socket = connect_new_request_server_client(*protocol).release_value_but_fixme_should_propagate_errors();
+            request_server_socket = AK::move(socket);
         }
 
         auto candidate_web_content_paths = get_paths_for_helper_process("WebContent"sv).release_value_but_fixme_should_propagate_errors();
-        auto new_client = launch_web_content_process(*this, candidate_web_content_paths, m_web_content_options, AK::move(request_server_sockets)).release_value_but_fixme_should_propagate_errors();
+        auto new_client = launch_web_content_process(*this, candidate_web_content_paths, m_web_content_options, AK::move(request_server_socket)).release_value_but_fixme_should_propagate_errors();
 
         m_client_state.client = new_client;
     } else {

Ladybird/RequestServer/main.cpp

@@ -20,7 +20,6 @@
 #include <RequestServer/HttpProtocol.h>
 #include <RequestServer/HttpsProtocol.h>
 
-// FIXME: Share b/w RequestServer and WebSocket
 ErrorOr<ByteString> find_certificates(StringView serenity_resource_root)
 {
     auto cert_path = ByteString::formatted("{}/ladybird/cacert.pem", serenity_resource_root);
@@ -33,12 +32,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 {
     AK::set_rich_debug_enabled(true);
 
-    int fd_passing_socket { -1 };
     StringView serenity_resource_root;
     Vector<ByteString> certificates;
 
     Core::ArgsParser args_parser;
-    args_parser.add_option(fd_passing_socket, "File descriptor of the fd passing socket", "fd-passing-socket", 'c', "fd-passing-socket");
     args_parser.add_option(certificates, "Path to a certificate file", "certificate", 'C', "certificate");
     args_parser.add_option(serenity_resource_root, "Absolute path to directory for serenity resources", "serenity-resource-root", 'r', "serenity-resource-root");
     args_parser.parse(arguments);
@@ -56,7 +53,6 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     RequestServer::HttpsProtocol::install();
 
     auto client = TRY(IPC::take_over_accepted_client_from_system_server<RequestServer::ConnectionFromClient>());
-    client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(fd_passing_socket)));
 
     return event_loop.exec();
 }

Ladybird/WebContent/main.cpp

@@ -51,7 +51,7 @@
 
 static ErrorOr<void> load_content_filters();
 static ErrorOr<void> load_autoplay_allowlist();
-static ErrorOr<void> initialize_lagom_networking(int request_server_socket, int request_server_fd_passing_socket);
+static ErrorOr<void> initialize_lagom_networking(int request_server_socket);
 
 namespace JS {
 extern bool g_log_all_js_exceptions;
@@ -92,9 +92,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     StringView executable_path {};
     StringView mach_server_name {};
     Vector<ByteString> certificates;
-    int webcontent_fd_passing_socket { -1 };
     int request_server_socket { -1 };
-    int request_server_fd_passing_socket { -1 };
     bool is_layout_test_mode = false;
     bool use_lagom_networking = false;
     bool use_gpu_painting = false;
@@ -105,9 +103,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     Core::ArgsParser args_parser;
     args_parser.add_option(command_line, "Chrome process command line", "command-line", 0, "command_line");
     args_parser.add_option(executable_path, "Chrome process executable path", "executable-path", 0, "executable_path");
-    args_parser.add_option(webcontent_fd_passing_socket, "File descriptor of the passing socket for the WebContent connection", "webcontent-fd-passing-socket", 'c', "webcontent_fd_passing_socket");
     args_parser.add_option(request_server_socket, "File descriptor of the socket for the RequestServer connection", "request-server-socket", 'r', "request_server_socket");
-    args_parser.add_option(request_server_fd_passing_socket, "File descriptor of the fd passing socket for the RequestServer connection", "request-server-fd-passing-socket", 'f', "request_server_fd_passing_socket");
     args_parser.add_option(is_layout_test_mode, "Is layout test mode", "layout-test-mode", 0);
     args_parser.add_option(use_lagom_networking, "Enable Lagom servers for networking", "use-lagom-networking", 0);
     args_parser.add_option(use_gpu_painting, "Enable GPU painting", "use-gpu-painting", 0);
@@ -139,12 +135,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         Web::ResourceLoader::initialize(Ladybird::RequestManagerQt::create());
     else
 #endif
-        TRY(initialize_lagom_networking(request_server_socket, request_server_fd_passing_socket));
+        TRY(initialize_lagom_networking(request_server_socket));
 
     Web::HTML::Window::set_internals_object_exposed(is_layout_test_mode);
 
-    VERIFY(webcontent_fd_passing_socket >= 0);
-
     Web::Platform::FontPlugin::install(*new Ladybird::FontPlugin(is_layout_test_mode));
 
     TRY(Web::Bindings::initialize_main_thread_vm());
@@ -167,7 +161,6 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     auto webcontent_socket = TRY(Core::take_over_socket_from_system_server("WebContent"sv));
     auto webcontent_client = TRY(WebContent::ConnectionFromClient::try_create(move(webcontent_socket)));
-    webcontent_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(webcontent_fd_passing_socket)));
 
     return event_loop.exec();
 }
@@ -220,13 +213,12 @@ static ErrorOr<void> load_autoplay_allowlist()
     return {};
 }
 
-ErrorOr<void> initialize_lagom_networking(int request_server_socket, int request_server_fd_passing_socket)
+ErrorOr<void> initialize_lagom_networking(int request_server_socket)
 {
     auto socket = TRY(Core::LocalSocket::adopt_fd(request_server_socket));
     TRY(socket->set_blocking(true));
 
     auto new_client = TRY(try_make_ref_counted<Protocol::RequestClient>(move(socket)));
-    new_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(request_server_fd_passing_socket)));
 
     Web::ResourceLoader::initialize(TRY(WebView::RequestServerAdapter::try_create(move(new_client))));
     return {};

Ladybird/WebWorker/main.cpp

@@ -26,21 +26,17 @@
 #include <LibWebView/WebSocketClientAdapter.h>
 #include <WebWorker/ConnectionFromClient.h>
 
-static ErrorOr<void> initialize_lagom_networking(int request_server_socket, int request_server_fd_passing_socket);
+static ErrorOr<void> initialize_lagom_networking(int request_server_socket);
 
 ErrorOr<int> serenity_main(Main::Arguments arguments)
 {
     AK::set_rich_debug_enabled(true);
 
-    int fd_passing_socket { -1 };
     int request_server_socket { -1 };
-    int request_server_fd_passing_socket { -1 };
     StringView serenity_resource_root;
 
     Core::ArgsParser args_parser;
-    args_parser.add_option(fd_passing_socket, "File descriptor of the fd passing socket", "fd-passing-socket", 'c', "fd-passing-socket");
     args_parser.add_option(request_server_socket, "File descriptor of the request server socket", "request-server-socket", 's', "request-server-socket");
-    args_parser.add_option(request_server_fd_passing_socket, "File descriptor of the request server fd passing socket", "request-server-fd-passing-socket", 'f', "request-server-fd-passing-socket");
     args_parser.add_option(serenity_resource_root, "Absolute path to directory for serenity resources", "serenity-resource-root", 'r', "serenity-resource-root");
     args_parser.parse(arguments);
 
@@ -51,25 +47,21 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     Web::Platform::FontPlugin::install(*new Web::Platform::FontPluginSerenity);
 
-    TRY(initialize_lagom_networking(request_server_socket, request_server_fd_passing_socket));
-
-    VERIFY(fd_passing_socket >= 0);
+    TRY(initialize_lagom_networking(request_server_socket));
 
     TRY(Web::Bindings::initialize_main_thread_vm());
 
     auto client = TRY(IPC::take_over_accepted_client_from_system_server<WebWorker::ConnectionFromClient>());
-    client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(fd_passing_socket)));
 
     return event_loop.exec();
 }
 
-static ErrorOr<void> initialize_lagom_networking(int request_server_socket, int request_server_fd_passing_socket)
+static ErrorOr<void> initialize_lagom_networking(int request_server_socket)
 {
     auto socket = TRY(Core::LocalSocket::adopt_fd(request_server_socket));
     TRY(socket->set_blocking(true));
 
     auto new_client = TRY(try_make_ref_counted<Protocol::RequestClient>(move(socket)));
-    new_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(request_server_fd_passing_socket)));
 
     Web::ResourceLoader::initialize(TRY(WebView::RequestServerAdapter::try_create(move(new_client))));
 

Meta/gn/secondary/Userland/Libraries/LibWebView/BUILD.gn

@@ -125,7 +125,6 @@ shared_library("LibWebView") {
     "ProcessManager.cpp",
     "RequestServerAdapter.cpp",
     "SearchEngine.cpp",
-    "SocketPair.cpp",
     "SourceHighlighter.cpp",
     "URL.cpp",
     "UserAgent.cpp",

Userland/Libraries/LibIPC/Connection.h

@@ -40,7 +40,6 @@ class ConnectionBase : public Core::EventReceiver {
 public:
     virtual ~ConnectionBase() override = default;
 
-    void set_fd_passing_socket(NonnullOwnPtr<Core::LocalSocket>) { }
     void set_deferred_invoker(NonnullOwnPtr<DeferredInvoker>);
     DeferredInvoker& deferred_invoker() { return *m_deferred_invoker; }
 
@@ -51,7 +50,6 @@ public:
     virtual void die() { }
 
     Core::LocalSocket& socket() { return *m_socket; }
-    Core::LocalSocket const& fd_passing_socket() const { return *m_socket; }
 
 protected:
     explicit ConnectionBase(IPC::Stub&, NonnullOwnPtr<Core::LocalSocket>, u32 local_endpoint_magic);

Userland/Libraries/LibWeb/HTML/MessagePort.cpp

@@ -83,11 +83,6 @@ WebIDL::ExceptionOr<void> MessagePort::transfer_steps(HTML::TransferDataHolder&
         m_socket = nullptr;
         data_holder.fds.append(IPC::File::adopt_fd(fd));
         data_holder.data.append(IPC_FILE_TAG);
-
-        auto fd_passing_socket = MUST(m_fd_passing_socket->release_fd());
-        m_fd_passing_socket = nullptr;
-        data_holder.fds.append(IPC::File::adopt_fd(fd_passing_socket));
-        data_holder.data.append(IPC_FILE_TAG);
     }
 
     // 4. Otherwise, set dataHolder.[[RemotePort]] to null.
@@ -114,11 +109,6 @@ WebIDL::ExceptionOr<void> MessagePort::transfer_receiving_steps(HTML::TransferDa
         auto fd = data_holder.fds.take_first();
         m_socket = MUST(Core::LocalSocket::adopt_fd(fd.take_fd()));
 
-        fd_tag = data_holder.data.take_first();
-        VERIFY(fd_tag == IPC_FILE_TAG);
-        fd = data_holder.fds.take_first();
-        m_fd_passing_socket = MUST(Core::LocalSocket::adopt_fd(fd.take_fd()));
-
         m_socket->on_ready_to_read = [strong_this = JS::make_handle(this)]() {
             strong_this->read_from_socket();
         };
@@ -137,7 +127,6 @@ void MessagePort::disentangle()
     m_remote_port = nullptr;
 
     m_socket = nullptr;
-    m_fd_passing_socket = nullptr;
 }
 
 // https://html.spec.whatwg.org/multipage/web-messaging.html#entangle
@@ -181,10 +170,6 @@ void MessagePort::entangle_with(MessagePort& remote_port)
     m_remote_port->m_socket->on_ready_to_read = [remote_port = JS::make_handle(m_remote_port)]() {
         remote_port->read_from_socket();
     };
-
-    auto fd_sockets = create_paired_sockets();
-    m_fd_passing_socket = move(fd_sockets[0]);
-    m_remote_port->m_fd_passing_socket = move(fd_sockets[1]);
 }
 
 // https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messageport-postmessage-options
@@ -408,7 +393,6 @@ void MessagePort::start()
         return;
 
     VERIFY(m_socket);
-    VERIFY(m_fd_passing_socket);
 
     // TODO: The start() method steps are to enable this's port message queue, if it is not already enabled.
 }

Userland/Libraries/LibWeb/HTML/MessagePort.h

@@ -91,7 +91,6 @@ private:
     bool m_has_been_shipped { false };
 
     OwnPtr<Core::LocalSocket> m_socket;
-    OwnPtr<Core::LocalSocket> m_fd_passing_socket;
 
     enum class SocketState : u8 {
         Header,

Userland/Libraries/LibWeb/HTML/WorkerAgent.cpp

@@ -33,14 +33,11 @@ void WorkerAgent::initialize(JS::Realm& realm)
 
     // NOTE: This blocking IPC call may launch another process.
     //    If spinning the event loop for this can cause other javascript to execute, we're in trouble.
-    auto worker_ipc_sockets = Bindings::host_defined_page(realm).client().request_worker_agent();
-    auto worker_socket = MUST(Core::LocalSocket::adopt_fd(worker_ipc_sockets.socket.take_fd()));
+    auto worker_socket_file = Bindings::host_defined_page(realm).client().request_worker_agent();
+    auto worker_socket = MUST(Core::LocalSocket::adopt_fd(worker_socket_file.take_fd()));
     MUST(worker_socket->set_blocking(true));
 
-    auto fd_passing_socket = MUST(Core::LocalSocket::adopt_fd(worker_ipc_sockets.fd_passing_socket.take_fd()));
-
     m_worker_ipc = make_ref_counted<WebWorkerClient>(move(worker_socket));
-    m_worker_ipc->set_fd_passing_socket(move(fd_passing_socket));
 
     m_worker_ipc->async_start_dedicated_worker(m_url, m_worker_options.type, m_worker_options.credentials, m_worker_options.name, move(data_holder), m_outside_settings->serialize());
 }

Userland/Libraries/LibWeb/Page/Page.h

@@ -38,7 +38,6 @@
 #include <LibWeb/HTML/WebViewHints.h>
 #include <LibWeb/Loader/FileRequest.h>
 #include <LibWeb/PixelUnits.h>
-#include <LibWebView/SocketPair.h>
 
 namespace Web {
 
@@ -315,7 +314,7 @@ public:
 
     virtual void page_did_change_audio_play_state(HTML::AudioPlayState) { }
 
-    virtual WebView::SocketPair request_worker_agent() { return { IPC::File {}, IPC::File {} }; }
+    virtual IPC::File request_worker_agent() { return IPC::File {}; }
 
     virtual void inspector_did_load() { }
     virtual void inspector_did_select_dom_node([[maybe_unused]] i32 node_id, [[maybe_unused]] Optional<CSS::Selector::PseudoElement::Type> const& pseudo_element) { }

Userland/Libraries/LibWeb/Worker/WebWorkerClient.cpp

@@ -19,12 +19,9 @@ WebWorkerClient::WebWorkerClient(NonnullOwnPtr<Core::LocalSocket> socket)
 {
 }
 
-WebView::SocketPair WebWorkerClient::dup_sockets()
+IPC::File WebWorkerClient::dup_socket()
 {
-    WebView::SocketPair pair;
-    pair.socket = MUST(IPC::File::clone_fd(socket().fd().value()));
-    pair.fd_passing_socket = MUST(IPC::File::clone_fd(fd_passing_socket().fd().value()));
-    return pair;
+    return MUST(IPC::File::clone_fd(socket().fd().value()));
 }
 
 }

Userland/Libraries/LibWeb/Worker/WebWorkerClient.h

@@ -10,7 +10,6 @@
 #include <LibIPC/ConnectionToServer.h>
 #include <LibWeb/Worker/WebWorkerClientEndpoint.h>
 #include <LibWeb/Worker/WebWorkerServerEndpoint.h>
-#include <LibWebView/SocketPair.h>
 
 namespace Web::HTML {
 
@@ -22,7 +21,7 @@ class WebWorkerClient final
 public:
     explicit WebWorkerClient(NonnullOwnPtr<Core::LocalSocket>);
 
-    WebView::SocketPair dup_sockets();
+    IPC::File dup_socket();
 
 private:
     virtual void die() override;

Userland/Libraries/LibWebView/CMakeLists.txt

@@ -9,7 +9,6 @@ set(SOURCES
     ProcessManager.cpp
     RequestServerAdapter.cpp
     SearchEngine.cpp
-    SocketPair.cpp
     SourceHighlighter.cpp
     URL.cpp
     UserAgent.cpp

Userland/Libraries/LibWebView/Forward.h

@@ -22,7 +22,6 @@ struct Attribute;
 struct CookieStorageKey;
 struct ProcessHandle;
 struct SearchEngine;
-struct SocketPair;
 
 }
 

Userland/Libraries/LibWebView/OutOfProcessWebView.cpp

@@ -75,7 +75,7 @@ OutOfProcessWebView::OutOfProcessWebView()
 
     on_request_worker_agent = []() {
         auto worker_client = MUST(Web::HTML::WebWorkerClient::try_create());
-        return worker_client->dup_sockets();
+        return worker_client->dup_socket();
     };
 }
 

Userland/Libraries/LibWebView/SocketPair.cpp

@@ -1,26 +0,0 @@
-/*
- * Copyright (c) 2024, Andrew Kaster <akaster@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <LibIPC/Decoder.h>
-#include <LibIPC/Encoder.h>
-#include <LibWebView/SocketPair.h>
-
-template<>
-ErrorOr<void> IPC::encode(Encoder& encoder, WebView::SocketPair const& pair)
-{
-    TRY(encoder.encode(pair.socket));
-    TRY(encoder.encode(pair.fd_passing_socket));
-    return {};
-}
-
-template<>
-ErrorOr<WebView::SocketPair> IPC::decode(Decoder& decoder)
-{
-    auto socket = TRY(decoder.decode<IPC::File>());
-    auto fd_passing_socket = TRY(decoder.decode<IPC::File>());
-
-    return WebView::SocketPair { move(socket), move(fd_passing_socket) };
-}

Userland/Libraries/LibWebView/SocketPair.h

@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2024, Andrew Kaster <akaster@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <LibIPC/File.h>
-
-namespace WebView {
-
-struct SocketPair {
-    IPC::File socket;
-    IPC::File fd_passing_socket;
-};
-
-}
-
-namespace IPC {
-
-template<>
-ErrorOr<void> encode(Encoder&, WebView::SocketPair const&);
-
-template<>
-ErrorOr<WebView::SocketPair> decode(Decoder&);
-
-}

Userland/Libraries/LibWebView/ViewImplementation.h

@@ -200,7 +200,7 @@ public:
     Function<void(i32, size_t, Vector<Attribute> const&)> on_inspector_replaced_dom_node_attribute;
     Function<void(i32, Gfx::IntPoint, String const&, Optional<String> const&, Optional<size_t> const&)> on_inspector_requested_dom_tree_context_menu;
     Function<void(String const&)> on_inspector_executed_console_script;
-    Function<SocketPair()> on_request_worker_agent;
+    Function<IPC::File()> on_request_worker_agent;
 
     virtual Web::DevicePixelRect viewport_rect() const = 0;
     virtual Gfx::IntPoint to_content_position(Gfx::IntPoint widget_position) const = 0;

Userland/Libraries/LibWebView/WebContentClient.cpp

@@ -665,7 +665,7 @@ Messages::WebContentClient::RequestWorkerAgentResponse WebContentClient::request
             return view->on_request_worker_agent();
     }
 
-    return WebView::SocketPair { IPC::File {}, IPC::File {} };
+    return IPC::File {};
 }
 
 Optional<ViewImplementation&> WebContentClient::view_for_page_id(u64 page_id, SourceLocation location)

Userland/Services/RequestServer/ConnectionFromClient.cpp

@@ -42,12 +42,10 @@ void ConnectionFromClient::die()
 
 Messages::RequestServer::ConnectNewClientResponse ConnectionFromClient::connect_new_client()
 {
-    Messages::RequestServer::ConnectNewClientResponse error_response = { IPC::File {}, IPC::File {} };
-
     int socket_fds[2] {};
     if (auto err = Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, socket_fds); err.is_error()) {
         dbgln("Failed to create client socketpair: {}", err.error());
-        return error_response;
+        return IPC::File {};
     }
 
     auto client_socket_or_error = Core::LocalSocket::adopt_fd(socket_fds[0]);
@@ -55,32 +53,13 @@ Messages::RequestServer::ConnectNewClientResponse ConnectionFromClient::connect_
         close(socket_fds[0]);
         close(socket_fds[1]);
         dbgln("Failed to adopt client socket: {}", client_socket_or_error.error());
-        return error_response;
+        return IPC::File {};
     }
     auto client_socket = client_socket_or_error.release_value();
     // Note: A ref is stored in the static s_connections map
     auto client = adopt_ref(*new ConnectionFromClient(move(client_socket)));
 
-    int fd_passing_socket_fds[2] {};
-    if (auto err = Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, fd_passing_socket_fds); err.is_error()) {
-        close(socket_fds[1]);
-        dbgln("Failed to create fd-passing socketpair: {}", err.error());
-        return error_response;
-    }
-
-    auto fd_passing_socket_or_error = Core::LocalSocket::adopt_fd(fd_passing_socket_fds[0]);
-    if (fd_passing_socket_or_error.is_error()) {
-        // socket_fds[0] is already owned by client
-        close(socket_fds[1]);
-        close(fd_passing_socket_fds[0]);
-        close(fd_passing_socket_fds[1]);
-        dbgln("Failed to adopt fd-passing socket: {}", fd_passing_socket_or_error.error());
-        return error_response;
-    }
-    auto fd_passing_socket = fd_passing_socket_or_error.release_value();
-    client->set_fd_passing_socket(move(fd_passing_socket));
-
-    return { IPC::File::adopt_fd(socket_fds[1]), IPC::File::adopt_fd(fd_passing_socket_fds[1]) };
+    return IPC::File::adopt_fd(socket_fds[1]);
 }
 
 Messages::RequestServer::IsSupportedProtocolResponse ConnectionFromClient::is_supported_protocol(ByteString const& protocol)

Userland/Services/RequestServer/RequestServer.ipc

@@ -3,7 +3,7 @@
 
 endpoint RequestServer
 {
-    connect_new_client() => (IPC::File client_socket, IPC::File client_fd_passing_socket)
+    connect_new_client() => (IPC::File client_socket)
 
     // Test if a specific protocol is supported, e.g "http"
     is_supported_protocol(ByteString protocol) => (bool supported)

Userland/Services/WebContent/PageClient.cpp

@@ -24,7 +24,6 @@
 #include <LibWeb/Painting/ViewportPaintable.h>
 #include <LibWeb/Platform/Timer.h>
 #include <LibWebView/Attribute.h>
-#include <LibWebView/SocketPair.h>
 #include <WebContent/ConnectionFromClient.h>
 #include <WebContent/PageClient.h>
 #include <WebContent/PageHost.h>
@@ -601,7 +600,7 @@ void PageClient::page_did_change_audio_play_state(Web::HTML::AudioPlayState play
     client().async_did_change_audio_play_state(m_id, play_state);
 }
 
-WebView::SocketPair PageClient::request_worker_agent()
+IPC::File PageClient::request_worker_agent()
 {
     auto response = client().send_sync_but_allow_failure<Messages::WebContentClient::RequestWorkerAgent>(m_id);
     if (!response) {
@@ -609,7 +608,7 @@ WebView::SocketPair PageClient::request_worker_agent()
         exit(0);
     }
 
-    return response->take_sockets();
+    return response->take_socket();
 }
 
 void PageClient::inspector_did_load()

Userland/Services/WebContent/PageClient.h

@@ -146,7 +146,7 @@ private:
     virtual void page_did_change_theme_color(Gfx::Color color) override;
     virtual void page_did_insert_clipboard_entry(String data, String presentation_style, String mime_type) override;
     virtual void page_did_change_audio_play_state(Web::HTML::AudioPlayState) override;
-    virtual WebView::SocketPair request_worker_agent() override;
+    virtual IPC::File request_worker_agent() override;
     virtual void inspector_did_load() override;
     virtual void inspector_did_select_dom_node(i32 node_id, Optional<Web::CSS::Selector::PseudoElement::Type> const& pseudo_element) override;
     virtual void inspector_did_set_dom_node_text(i32 node_id, String const& text) override;

Userland/Services/WebContent/WebContentClient.ipc

@@ -13,7 +13,6 @@
 #include <LibWeb/HTML/WebViewHints.h>
 #include <LibWeb/Page/Page.h>
 #include <LibWebView/Attribute.h>
-#include <LibWebView/SocketPair.h>
 #include <LibWebView/ProcessHandle.h>
 
 endpoint WebContentClient
@@ -91,7 +90,7 @@ endpoint WebContentClient
 
     did_finish_text_test(u64 page_id) =|
 
-    request_worker_agent(u64 page_id) => (WebView::SocketPair sockets) // FIXME: Add required attributes to select a SharedWorker Agent
+    request_worker_agent(u64 page_id) => (IPC::File socket) // FIXME: Add required attributes to select a SharedWorker Agent
 
     inspector_did_load(u64 page_id) =|
     inspector_did_select_dom_node(u64 page_id, i32 node_id, Optional<Web::CSS::Selector::PseudoElement::Type> pseudo_element) =|

Userland/Utilities/headless-browser.cpp

@@ -96,10 +96,10 @@ public:
             .is_layout_test_mode = is_layout_test_mode,
         };
 
-        auto request_server_sockets = TRY(connect_new_request_server_client(*request_client));
+        auto request_server_socket = TRY(connect_new_request_server_client(*request_client));
 
         auto candidate_web_content_paths = TRY(get_paths_for_helper_process("WebContent"sv));
-        view->m_client_state.client = TRY(launch_web_content_process(*view, candidate_web_content_paths, web_content_options, move(request_server_sockets)));
+        view->m_client_state.client = TRY(launch_web_content_process(*view, candidate_web_content_paths, web_content_options, move(request_server_socket)));
 #endif
 
         view->client().async_update_system_theme(0, move(theme));
@@ -196,7 +196,7 @@ private:
 #else
             auto worker_client = MUST(launch_web_worker_process(MUST(get_paths_for_helper_process("WebWorker"sv)), *m_request_client));
 #endif
-            return worker_client->dup_sockets();
+            return worker_client->dup_socket();
         };
     }