Add dbus system service (#83)

In cases where we are switchting users which are not allowed or are using a non graphical shell dbus user session will not work.
User session are bound to xauthority and display environment variables. In those cases fallback to a system session running as specified user (default=root).

Fixes: https://github.com/janbrummer/libproxy2/issues/79

Co-authored-by: Jan-Michael Brummer <jan-michael.brummer1@volkswagen.de>

8 files changed, 89 insertions, 49 deletions

diff --git a/meson_options.txt b/meson_options.txt
index 04389b9..2927b76 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -16,7 +16,14 @@ option(
   'dbus',
   type: 'feature',
   value: 'auto',
-  description: 'Whether to build dbus service'
+  description: 'Whether to build D-Bus service'
+)
+
+option(
+  'dbus-system-user',
+  type: 'string',
+  value: 'root',
+  description: 'Which user should be used on D-Bus system session'
 )
 
 option(
@@ -87,4 +94,4 @@ option(
   type: 'boolean',
   value: true,
   description: 'Whether to build introspection support'
-)
\ No newline at end of file
+)
diff --git a/src/backend/dbus/dbus.c b/src/backend/dbus/dbus.c
index a04c0f9..645b5e9 100644
--- a/src/backend/dbus/dbus.c
+++ b/src/backend/dbus/dbus.c
@@ -124,7 +124,8 @@ on_name_lost (GDBusConnection *connection,
     g_warning ("Can't connect proxy bus");
     g_main_loop_quit (user_data);
   } else {
-    g_error ("Unknown name lost error");
+    g_warning ("Unknown name lost error");
+    g_main_loop_quit (user_data);
   }
 }
 
@@ -133,12 +134,43 @@ main (int    argc,
       char **argv)
 {
   GMainLoop *loop;
+  GBusNameOwnerFlags flags;
+  gboolean replace;
+  gboolean use_system;
+  GOptionContext *context;
+  g_autoptr (GError) error = NULL;
+  const GOptionEntry options[] = {
+    { "replace", 'r', 0, G_OPTION_ARG_NONE, &replace, "Replace old daemon.", NULL },
+    { "system", 's', 0, G_OPTION_ARG_NONE, &use_system, "Use system session.", NULL },
+    { NULL }
+  };
+
+  replace = FALSE;
+  use_system = FALSE;
+
+  context = g_option_context_new ("");
+  g_option_context_set_summary (context, "Libproxy D-Bus Service");
+  g_option_context_add_main_entries (context, options, "libproxy");
+
+  if (!g_option_context_parse (context, &argc, &argv, &error)) {
+    g_printerr ("%s: %s", g_get_application_name (), error->message);
+    g_printerr ("\n");
+    g_printerr ("Try \"%s --help\" for more information.",
+                g_get_prgname ());
+    g_printerr ("\n");
+    g_option_context_free (context);
+    return 1;
+  }
 
   loop = g_main_loop_new (NULL, FALSE);
 
-  g_bus_own_name (G_BUS_TYPE_SESSION,
+  flags = G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT;
+  if (replace)
+    flags |= G_BUS_NAME_OWNER_FLAGS_REPLACE;
+
+  g_bus_own_name (use_system ? G_BUS_TYPE_SYSTEM : G_BUS_TYPE_SESSION,
                   "org.libproxy.proxy",
-                  G_BUS_NAME_OWNER_FLAGS_NONE,
+                  flags,
                   on_bus_acquired,
                   NULL,
                   on_name_lost,
diff --git a/src/backend/dbus/meson.build b/src/backend/dbus/meson.build
index eb64fcd..250a105 100644
--- a/src/backend/dbus/meson.build
+++ b/src/backend/dbus/meson.build
@@ -4,13 +4,10 @@ if build_dbus
   unitdir = ''
   dbus_data_dir = join_paths(get_option('prefix'), get_option('datadir'), 'dbus-1')
   dbus_interfaces_dir = join_paths(dbus_data_dir, 'interfaces')
-  dbus_services_dir = join_paths(dbus_data_dir, 'services')
-  dbus_sysconf_dir = join_paths(dbus_data_dir, 'session.d')
-
-  systemd = dependency('systemd', required: false)
-  if systemd.found()
-    unitdir = systemd.get_variable(pkgconfig: 'systemduserunitdir')
-  endif
+  dbus_user_services_dir = join_paths(dbus_data_dir, 'services')
+  dbus_system_services_dir = join_paths(dbus_data_dir, 'system-services')
+  dbus_user_conf_dir = join_paths(dbus_data_dir, 'session.d')
+  dbus_system_conf_dir = join_paths(dbus_data_dir, 'system.d')
 
   px_interface = [
     'org.libproxy.proxy.xml'
@@ -59,29 +56,29 @@ if build_dbus
     install: true,
   )
 
-  service_data = configuration_data()
-  service_data.set('LIBEXECDIR', join_paths(px_prefix, get_option('libexecdir')))
+  # D-Bus Interface
+  install_data('org.libproxy.proxy.xml', install_dir : dbus_interfaces_dir)
 
-  dbus_service = configure_file(
+  # D-Bus User Service
+  user_service_data = configuration_data()
+  user_service_data.set('LIBEXECDIR', join_paths(px_prefix, get_option('libexecdir')))
+  dbus_user_service = configure_file(
     input: 'org.libproxy.proxy.service.in',
     output: 'org.libproxy.proxy.service',
-    configuration: service_data
+    configuration: user_service_data
   )
+  install_data(dbus_user_service, install_dir : dbus_user_services_dir)
+  install_data('org.libproxy.proxy.conf', install_dir : dbus_user_conf_dir)
 
-  install_data('org.libproxy.proxy.conf', install_dir : dbus_sysconf_dir)
-  install_data(dbus_service, install_dir : dbus_services_dir)
-  install_data('org.libproxy.proxy.xml', install_dir : dbus_interfaces_dir)
-
-  service_data = configuration_data()
-  service_data.set('LIBEXECDIR', join_paths(px_prefix, get_option('libexecdir')))
-
-  service = configure_file(
-    input: 'proxyd.service.in',
-    output: 'proxyd.service',
-    configuration: service_data
+  # D-Bus System Service
+  system_service_data = configuration_data()
+  system_service_data.set('LIBEXECDIR', join_paths(px_prefix, get_option('libexecdir')))
+  system_service_data.set('USER', get_option('dbus-system-user'))
+  dbus_system_service = configure_file(
+    input: 'org.libproxy.proxy-system.service.in',
+    output: 'org.libproxy.proxy-system.service',
+    configuration: system_service_data
   )
-
-  if unitdir != ''
-    install_data(service, install_dir: unitdir)
-  endif
+  install_data(dbus_system_service, rename : 'org.libproxy.proxy.service', install_dir : dbus_system_services_dir)
+  install_data('org.libproxy.proxy.conf', install_dir : dbus_system_conf_dir)
 endif
diff --git a/src/backend/dbus/org.libproxy.proxy-system.service.in b/src/backend/dbus/org.libproxy.proxy-system.service.in
new file mode 100644
index 0000000..2af960b
--- /dev/null
+++ b/src/backend/dbus/org.libproxy.proxy-system.service.in
@@ -0,0 +1,4 @@
+[D-BUS Service]
+Name=org.libproxy.proxy
+Exec=@LIBEXECDIR@/proxyd --system
+User=@USER@
diff --git a/src/backend/dbus/org.libproxy.proxy.service.in b/src/backend/dbus/org.libproxy.proxy.service.in
index e958cd2..d1ac5f4 100644
--- a/src/backend/dbus/org.libproxy.proxy.service.in
+++ b/src/backend/dbus/org.libproxy.proxy.service.in
@@ -1,3 +1,3 @@
 [D-BUS Service]
 Name=org.libproxy.proxy
-Exec=@LIBEXECDIR@/proxyd
\ No newline at end of file
+Exec=@LIBEXECDIR@/proxyd
diff --git a/src/backend/dbus/proxyd.service.in b/src/backend/dbus/proxyd.service.in
deleted file mode 100644
index 038e86d..0000000
--- a/src/backend/dbus/proxyd.service.in
+++ /dev/null
@@ -1,14 +0,0 @@
-[Unit]
-Description=Libproxy user service
-
-[Service]
-Type=dbus
-BusName=org.libproxy.proxy
-ExecStart=@LIBEXECDIR@/proxyd
-#Environment="G_MESSAGES_DEBUG=all"
-
-MemoryDenyWriteExecute=yes
-PrivateTmp=yes
-ProtectHome=yes
-ProtectSystem=full
-RestrictRealtime=yes
\ No newline at end of file
diff --git a/src/libproxy/proxy-dbus.c b/src/libproxy/proxy-dbus.c
index 1587c73..6b594e3 100644
--- a/src/libproxy/proxy-dbus.c
+++ b/src/libproxy/proxy-dbus.c
@@ -73,6 +73,20 @@ px_proxy_factory_new (void)
                                                "org.libproxy.proxy",
                                                self->cancellable, /* GCancellable */
                                                &error);
+
+  if (!self->proxy) {
+    g_clear_error (&error);
+
+    self->proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
+                                                 G_DBUS_PROXY_FLAGS_NONE,
+                                                 NULL, /* GDBusInterfaceInfo */
+                                                 "org.libproxy.proxy",
+                                                 "/org/libproxy/proxy",
+                                                 "org.libproxy.proxy",
+                                                 self->cancellable, /* GCancellable */
+                                                 &error);
+  }
+
   if (!self->proxy)
     g_warning ("Could not create libproxy dbus proxy: %s", error->message);
 
diff --git a/src/tools/proxy.c b/src/tools/proxy.c
index 2d46578..2561265 100644
--- a/src/tools/proxy.c
+++ b/src/tools/proxy.c
@@ -54,7 +54,7 @@ print_proxies (char **proxies)
     return;
   }
 
-  for (j = 0; proxies[j] ; j++)
+  for (j = 0; proxies[j]; j++)
     printf ("%s%s", proxies[j], proxies[j + 1] ? " " : "\n");
 }
 
@@ -74,7 +74,7 @@ main (int    argc,
   }
   /* User entered some arguments on startup. skip interactive */
   if (argc > 1) {
-    for (i = 1; i < argc ; i++) {
+    for (i = 1; i < argc; i++) {
       /*
        * Get an array of proxies to use. These should be used
        * in the order returned. Only move on to the next proxy
@@ -88,7 +88,7 @@ main (int    argc,
   /* Interactive mode */
   else {
     /* For each URL we read on STDIN, get the proxies to use */
-    for (url[0] = '\0' ; fgets (url, 102400, stdin) != NULL ; ) {
+    for (url[0] = '\0'; fgets (url, 102400, stdin) != NULL;) {
       if (url[strlen (url) - 1] == '\n') url[strlen (url) - 1] = '\0';
 
       /*