ui/dbus-chardev.c

   1 /*
   2  * QEMU DBus display
   3  *
   4  * Copyright (c) 2021 Marc-André Lureau <marcandre.lureau@redhat.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu/osdep.h"
  25 #include "trace.h"
  26 #include "qapi/error.h"
  27 #include "qemu/config-file.h"
  28 #include "qemu/option.h"
  29
  30 #ifdef G_OS_UNIX
  31 #include <gio/gunixfdlist.h>
  32 #endif
  33
  34 #include "dbus.h"
  35
  36 static char *
  37 dbus_display_chardev_path(DBusChardev *chr)
  38 {
  39     return g_strdup_printf(DBUS_DISPLAY1_ROOT "/Chardev_%s",
  40                            CHARDEV(chr)->label);
  41 }
  42
  43 static void
  44 dbus_display_chardev_export(DBusDisplay *dpy, DBusChardev *chr)
  45 {
  46     g_autoptr(GDBusObjectSkeleton) sk = NULL;
  47     g_autofree char *path = dbus_display_chardev_path(chr);
  48
  49     if (chr->exported) {
  50         return;
  51     }
  52
  53     sk = g_dbus_object_skeleton_new(path);
  54     g_dbus_object_skeleton_add_interface(
  55         sk, G_DBUS_INTERFACE_SKELETON(chr->iface));
  56     g_dbus_object_manager_server_export(dpy->server, sk);
  57     chr->exported = true;
  58 }
  59
  60 static void
  61 dbus_display_chardev_unexport(DBusDisplay *dpy, DBusChardev *chr)
  62 {
  63     g_autofree char *path = dbus_display_chardev_path(chr);
  64
  65     if (!chr->exported) {
  66         return;
  67     }
  68
  69     g_dbus_object_manager_server_unexport(dpy->server, path);
  70     chr->exported = false;
  71 }
  72
  73 static int
  74 dbus_display_chardev_foreach(Object *obj, void *data)
  75 {
  76     DBusDisplay *dpy = DBUS_DISPLAY(data);
  77
  78     if (!CHARDEV_IS_DBUS(obj)) {
  79         return 0;
  80     }
  81
  82     dbus_display_chardev_export(dpy, DBUS_CHARDEV(obj));
  83
  84     return 0;
  85 }
  86
  87 static void
  88 dbus_display_on_notify(Notifier *notifier, void *data)
  89 {
  90     DBusDisplay *dpy = container_of(notifier, DBusDisplay, notifier);
  91     DBusDisplayEvent *event = data;
  92
  93     switch (event->type) {
  94     case DBUS_DISPLAY_CHARDEV_OPEN:
  95         dbus_display_chardev_export(dpy, event->chardev);
  96         break;
  97     case DBUS_DISPLAY_CHARDEV_CLOSE:
  98         dbus_display_chardev_unexport(dpy, event->chardev);
  99         break;
 100     }
 101 }
 102
 103 void
 104 dbus_chardev_init(DBusDisplay *dpy)
 105 {
 106     dpy->notifier.notify = dbus_display_on_notify;
 107     dbus_display_notifier_add(&dpy->notifier);
 108
 109     object_child_foreach(container_get(object_get_root(), "/chardevs"),
 110                          dbus_display_chardev_foreach, dpy);
 111 }
 112
 113 #ifdef G_OS_UNIX
 114 static gboolean
 115 dbus_chr_register(
 116     DBusChardev *dc,
 117     GDBusMethodInvocation *invocation,
 118     GUnixFDList *fd_list,
 119     GVariant *arg_stream,
 120     QemuDBusDisplay1Chardev *object)
 121 {
 122     g_autoptr(GError) err = NULL;
 123     int fd;
 124
 125     fd = g_unix_fd_list_get(fd_list, g_variant_get_handle(arg_stream), &err);
 126     if (err) {
 127         g_dbus_method_invocation_return_error(
 128             invocation,
 129             DBUS_DISPLAY_ERROR,
 130             DBUS_DISPLAY_ERROR_FAILED,
 131             "Couldn't get peer FD: %s", err->message);
 132         return DBUS_METHOD_INVOCATION_HANDLED;
 133     }
 134
 135     if (qemu_chr_add_client(CHARDEV(dc), fd) < 0) {
 136         g_dbus_method_invocation_return_error(invocation,
 137                                               DBUS_DISPLAY_ERROR,
 138                                               DBUS_DISPLAY_ERROR_FAILED,
 139                                               "Couldn't register FD!");
 140         close(fd);
 141         return DBUS_METHOD_INVOCATION_HANDLED;
 142     }
 143
 144     g_object_set(dc->iface,
 145                  "owner", g_dbus_method_invocation_get_sender(invocation),
 146                  NULL);
 147
 148     qemu_dbus_display1_chardev_complete_register(object, invocation, NULL);
 149     return DBUS_METHOD_INVOCATION_HANDLED;
 150 }
 151 #endif
 152
 153 static gboolean
 154 dbus_chr_send_break(
 155     DBusChardev *dc,
 156     GDBusMethodInvocation *invocation,
 157     QemuDBusDisplay1Chardev *object)
 158 {
 159     qemu_chr_be_event(CHARDEV(dc), CHR_EVENT_BREAK);
 160
 161     qemu_dbus_display1_chardev_complete_send_break(object, invocation);
 162     return DBUS_METHOD_INVOCATION_HANDLED;
 163 }
 164
 165 static void
 166 dbus_chr_open(Chardev *chr, ChardevBackend *backend,
 167               bool *be_opened, Error **errp)
 168 {
 169     ERRP_GUARD();
 170
 171     DBusChardev *dc = DBUS_CHARDEV(chr);
 172     DBusDisplayEvent event = {
 173         .type = DBUS_DISPLAY_CHARDEV_OPEN,
 174         .chardev = dc,
 175     };
 176     g_autoptr(ChardevBackend) be = NULL;
 177     g_autoptr(QemuOpts) opts = NULL;
 178
 179     dc->iface = qemu_dbus_display1_chardev_skeleton_new();
 180     g_object_set(dc->iface, "name", backend->u.dbus.data->name, NULL);
 181     g_object_connect(dc->iface,
 182 #ifdef G_OS_UNIX
 183                      "swapped-signal::handle-register",
 184                      dbus_chr_register, dc,
 185 #endif
 186                      "swapped-signal::handle-send-break",
 187                      dbus_chr_send_break, dc,
 188                      NULL);
 189
 190     dbus_display_notify(&event);
 191
 192     be = g_new0(ChardevBackend, 1);
 193     opts = qemu_opts_create(qemu_find_opts("chardev"), NULL, 0, &error_abort);
 194     qemu_opt_set(opts, "server", "on", &error_abort);
 195     qemu_opt_set(opts, "wait", "off", &error_abort);
 196     CHARDEV_CLASS(object_class_by_name(TYPE_CHARDEV_SOCKET))->parse(
 197         opts, be, errp);
 198     if (*errp) {
 199         return;
 200     }
 201     CHARDEV_CLASS(object_class_by_name(TYPE_CHARDEV_SOCKET))->open(
 202         chr, be, be_opened, errp);
 203 }
 204
 205 static void
 206 dbus_chr_set_fe_open(Chardev *chr, int fe_open)
 207 {
 208     DBusChardev *dc = DBUS_CHARDEV(chr);
 209
 210     g_object_set(dc->iface, "feopened", fe_open, NULL);
 211 }
 212
 213 static void
 214 dbus_chr_set_echo(Chardev *chr, bool echo)
 215 {
 216     DBusChardev *dc = DBUS_CHARDEV(chr);
 217
 218     g_object_set(dc->iface, "echo", echo, NULL);
 219 }
 220
 221 static void
 222 dbus_chr_be_event(Chardev *chr, QEMUChrEvent event)
 223 {
 224     DBusChardev *dc = DBUS_CHARDEV(chr);
 225     DBusChardevClass *klass = DBUS_CHARDEV_GET_CLASS(chr);
 226
 227     switch (event) {
 228     case CHR_EVENT_CLOSED:
 229         if (dc->iface) {
 230             /* on finalize, iface is set to NULL */
 231             g_object_set(dc->iface, "owner", "", NULL);
 232         }
 233         break;
 234     default:
 235         break;
 236     };
 237
 238     klass->parent_chr_be_event(chr, event);
 239 }
 240
 241 static void
 242 dbus_chr_parse(QemuOpts *opts, ChardevBackend *backend,
 243                Error **errp)
 244 {
 245     const char *name = qemu_opt_get(opts, "name");
 246     ChardevDBus *dbus;
 247
 248     if (name == NULL) {
 249         error_setg(errp, "chardev: dbus: no name given");
 250         return;
 251     }
 252
 253     backend->type = CHARDEV_BACKEND_KIND_DBUS;
 254     dbus = backend->u.dbus.data = g_new0(ChardevDBus, 1);
 255     qemu_chr_parse_common(opts, qapi_ChardevDBus_base(dbus));
 256     dbus->name = g_strdup(name);
 257 }
 258
 259 static void
 260 char_dbus_class_init(ObjectClass *oc, void *data)
 261 {
 262     DBusChardevClass *klass = DBUS_CHARDEV_CLASS(oc);
 263     ChardevClass *cc = CHARDEV_CLASS(oc);
 264
 265     cc->parse = dbus_chr_parse;
 266     cc->open = dbus_chr_open;
 267     cc->chr_set_fe_open = dbus_chr_set_fe_open;
 268     cc->chr_set_echo = dbus_chr_set_echo;
 269     klass->parent_chr_be_event = cc->chr_be_event;
 270     cc->chr_be_event = dbus_chr_be_event;
 271 }
 272
 273 static void
 274 char_dbus_finalize(Object *obj)
 275 {
 276     DBusChardev *dc = DBUS_CHARDEV(obj);
 277     DBusDisplayEvent event = {
 278         .type = DBUS_DISPLAY_CHARDEV_CLOSE,
 279         .chardev = dc,
 280     };
 281
 282     dbus_display_notify(&event);
 283     g_clear_object(&dc->iface);
 284 }
 285
 286 static const TypeInfo char_dbus_type_info = {
 287     .name = TYPE_CHARDEV_DBUS,
 288     .parent = TYPE_CHARDEV_SOCKET,
 289     .class_size = sizeof(DBusChardevClass),
 290     .instance_size = sizeof(DBusChardev),
 291     .instance_finalize = char_dbus_finalize,
 292     .class_init = char_dbus_class_init,
 293 };
 294 module_obj(TYPE_CHARDEV_DBUS);
 295
 296 static void
 297 register_types(void)
 298 {
 299     type_register_static(&char_dbus_type_info);
 300 }
 301
 302 type_init(register_types);