src/dbus.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <sys/epoll.h>
  23 #include <sys/timerfd.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26 #include <dbus/dbus.h>
  27
  28 #include "dbus.h"
  29 #include "log.h"
  30 #include "strv.h"
  31 #include "cgroup.h"
  32 #include "dbus-unit.h"
  33 #include "dbus-job.h"
  34 #include "dbus-manager.h"
  35 #include "dbus-service.h"
  36 #include "dbus-socket.h"
  37 #include "dbus-target.h"
  38 #include "dbus-device.h"
  39 #include "dbus-mount.h"
  40 #include "dbus-automount.h"
  41 #include "dbus-snapshot.h"
  42 #include "dbus-swap.h"
  43 #include "dbus-timer.h"
  44 #include "dbus-path.h"
  45 #include "bus-errors.h"
  46 #include "special.h"
  47 #include "dbus-common.h"
  48
  49 #define CONNECTIONS_MAX 52
  50
  51 static const char bus_properties_interface[] = BUS_PROPERTIES_INTERFACE;
  52 static const char bus_introspectable_interface[] = BUS_INTROSPECTABLE_INTERFACE;
  53
  54 const char *const bus_interface_table[] = {
  55         "org.freedesktop.DBus.Properties",     bus_properties_interface,
  56         "org.freedesktop.DBus.Introspectable", bus_introspectable_interface,
  57         "org.freedesktop.systemd1.Manager",    bus_manager_interface,
  58         "org.freedesktop.systemd1.Job",        bus_job_interface,
  59         "org.freedesktop.systemd1.Unit",       bus_unit_interface,
  60         "org.freedesktop.systemd1.Service",    bus_service_interface,
  61         "org.freedesktop.systemd1.Socket",     bus_socket_interface,
  62         "org.freedesktop.systemd1.Target",     bus_target_interface,
  63         "org.freedesktop.systemd1.Device",     bus_device_interface,
  64         "org.freedesktop.systemd1.Mount",      bus_mount_interface,
  65         "org.freedesktop.systemd1.Automount",  bus_automount_interface,
  66         "org.freedesktop.systemd1.Snapshot",   bus_snapshot_interface,
  67         "org.freedesktop.systemd1.Swap",       bus_swap_interface,
  68         "org.freedesktop.systemd1.Timer",      bus_timer_interface,
  69         "org.freedesktop.systemd1.Path",       bus_path_interface,
  70         NULL
  71 };
  72
  73 static void bus_done_api(Manager *m);
  74 static void bus_done_system(Manager *m);
  75 static void bus_done_private(Manager *m);
  76 static void shutdown_connection(Manager *m, DBusConnection *c);
  77
  78 static void bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data)  {
  79         Manager *m = data;
  80
  81         assert(bus);
  82         assert(m);
  83
  84         /* We maintain two sets, one for those connections where we
  85          * requested a dispatch, and another where we didn't. And then,
  86          * we move the connections between the two sets. */
  87
  88         if (status == DBUS_DISPATCH_COMPLETE)
  89                 set_move_one(m->bus_connections, m->bus_connections_for_dispatch, bus);
  90         else
  91                 set_move_one(m->bus_connections_for_dispatch, m->bus_connections, bus);
  92 }
  93
  94 static uint32_t bus_flags_to_events(DBusWatch *bus_watch) {
  95         unsigned flags;
  96         uint32_t events = 0;
  97
  98         assert(bus_watch);
  99
 100         /* no watch flags for disabled watches */
 101         if (!dbus_watch_get_enabled(bus_watch))
 102                 return 0;
 103
 104         flags = dbus_watch_get_flags(bus_watch);
 105
 106         if (flags & DBUS_WATCH_READABLE)
 107                 events |= EPOLLIN;
 108         if (flags & DBUS_WATCH_WRITABLE)
 109                 events |= EPOLLOUT;
 110
 111         return events | EPOLLHUP | EPOLLERR;
 112 }
 113
 114 static unsigned events_to_bus_flags(uint32_t events) {
 115         unsigned flags = 0;
 116
 117         if (events & EPOLLIN)
 118                 flags |= DBUS_WATCH_READABLE;
 119         if (events & EPOLLOUT)
 120                 flags |= DBUS_WATCH_WRITABLE;
 121         if (events & EPOLLHUP)
 122                 flags |= DBUS_WATCH_HANGUP;
 123         if (events & EPOLLERR)
 124                 flags |= DBUS_WATCH_ERROR;
 125
 126         return flags;
 127 }
 128
 129 void bus_watch_event(Manager *m, Watch *w, int events) {
 130         assert(m);
 131         assert(w);
 132
 133         /* This is called by the event loop whenever there is
 134          * something happening on D-Bus' file handles. */
 135
 136         if (!dbus_watch_get_enabled(w->data.bus_watch))
 137                 return;
 138
 139         dbus_watch_handle(w->data.bus_watch, events_to_bus_flags(events));
 140 }
 141
 142 static dbus_bool_t bus_add_watch(DBusWatch *bus_watch, void *data) {
 143         Manager *m = data;
 144         Watch *w;
 145         struct epoll_event ev;
 146
 147         assert(bus_watch);
 148         assert(m);
 149
 150         if (!(w = new0(Watch, 1)))
 151                 return FALSE;
 152
 153         w->fd = dbus_watch_get_unix_fd(bus_watch);
 154         w->type = WATCH_DBUS_WATCH;
 155         w->data.bus_watch = bus_watch;
 156
 157         zero(ev);
 158         ev.events = bus_flags_to_events(bus_watch);
 159         ev.data.ptr = w;
 160
 161         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
 162
 163                 if (errno != EEXIST) {
 164                         free(w);
 165                         return FALSE;
 166                 }
 167
 168                 /* Hmm, bloody D-Bus creates multiple watches on the
 169                  * same fd. epoll() does not like that. As a dirty
 170                  * hack we simply dup() the fd and hence get a second
 171                  * one we can safely add to the epoll(). */
 172
 173                 if ((w->fd = dup(w->fd)) < 0) {
 174                         free(w);
 175                         return FALSE;
 176                 }
 177
 178                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
 179                         close_nointr_nofail(w->fd);
 180                         free(w);
 181                         return FALSE;
 182                 }
 183
 184                 w->fd_is_dupped = true;
 185         }
 186
 187         dbus_watch_set_data(bus_watch, w, NULL);
 188
 189         return TRUE;
 190 }
 191
 192 static void bus_remove_watch(DBusWatch *bus_watch, void *data) {
 193         Manager *m = data;
 194         Watch *w;
 195
 196         assert(bus_watch);
 197         assert(m);
 198
 199         if (!(w = dbus_watch_get_data(bus_watch)))
 200                 return;
 201
 202         assert(w->type == WATCH_DBUS_WATCH);
 203         assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 204
 205         if (w->fd_is_dupped)
 206                 close_nointr_nofail(w->fd);
 207
 208         free(w);
 209 }
 210
 211 static void bus_toggle_watch(DBusWatch *bus_watch, void *data) {
 212         Manager *m = data;
 213         Watch *w;
 214         struct epoll_event ev;
 215
 216         assert(bus_watch);
 217         assert(m);
 218
 219         assert_se(w = dbus_watch_get_data(bus_watch));
 220         assert(w->type == WATCH_DBUS_WATCH);
 221
 222         zero(ev);
 223         ev.events = bus_flags_to_events(bus_watch);
 224         ev.data.ptr = w;
 225
 226         assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_MOD, w->fd, &ev) == 0);
 227 }
 228
 229 static int bus_timeout_arm(Manager *m, Watch *w) {
 230         struct itimerspec its;
 231
 232         assert(m);
 233         assert(w);
 234
 235         zero(its);
 236
 237         if (dbus_timeout_get_enabled(w->data.bus_timeout)) {
 238                 timespec_store(&its.it_value, dbus_timeout_get_interval(w->data.bus_timeout) * USEC_PER_MSEC);
 239                 its.it_interval = its.it_value;
 240         }
 241
 242         if (timerfd_settime(w->fd, 0, &its, NULL) < 0)
 243                 return -errno;
 244
 245         return 0;
 246 }
 247
 248 void bus_timeout_event(Manager *m, Watch *w, int events) {
 249         assert(m);
 250         assert(w);
 251
 252         /* This is called by the event loop whenever there is
 253          * something happening on D-Bus' file handles. */
 254
 255         if (!(dbus_timeout_get_enabled(w->data.bus_timeout)))
 256                 return;
 257
 258         dbus_timeout_handle(w->data.bus_timeout);
 259 }
 260
 261 static dbus_bool_t bus_add_timeout(DBusTimeout *timeout, void *data) {
 262         Manager *m = data;
 263         Watch *w;
 264         struct epoll_event ev;
 265
 266         assert(timeout);
 267         assert(m);
 268
 269         if (!(w = new0(Watch, 1)))
 270                 return FALSE;
 271
 272         if ((w->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 273                 goto fail;
 274
 275         w->type = WATCH_DBUS_TIMEOUT;
 276         w->data.bus_timeout = timeout;
 277
 278         if (bus_timeout_arm(m, w) < 0)
 279                 goto fail;
 280
 281         zero(ev);
 282         ev.events = EPOLLIN;
 283         ev.data.ptr = w;
 284
 285         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0)
 286                 goto fail;
 287
 288         dbus_timeout_set_data(timeout, w, NULL);
 289
 290         return TRUE;
 291
 292 fail:
 293         if (w->fd >= 0)
 294                 close_nointr_nofail(w->fd);
 295
 296         free(w);
 297         return FALSE;
 298 }
 299
 300 static void bus_remove_timeout(DBusTimeout *timeout, void *data) {
 301         Manager *m = data;
 302         Watch *w;
 303
 304         assert(timeout);
 305         assert(m);
 306
 307         if (!(w = dbus_timeout_get_data(timeout)))
 308                 return;
 309
 310         assert(w->type == WATCH_DBUS_TIMEOUT);
 311         assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 312         close_nointr_nofail(w->fd);
 313         free(w);
 314 }
 315
 316 static void bus_toggle_timeout(DBusTimeout *timeout, void *data) {
 317         Manager *m = data;
 318         Watch *w;
 319         int r;
 320
 321         assert(timeout);
 322         assert(m);
 323
 324         assert_se(w = dbus_timeout_get_data(timeout));
 325         assert(w->type == WATCH_DBUS_TIMEOUT);
 326
 327         if ((r = bus_timeout_arm(m, w)) < 0)
 328                 log_error("Failed to rearm timer: %s", strerror(-r));
 329 }
 330
 331 static DBusHandlerResult api_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
 332         Manager *m = data;
 333         DBusError error;
 334         DBusMessage *reply = NULL;
 335
 336         assert(connection);
 337         assert(message);
 338         assert(m);
 339
 340         dbus_error_init(&error);
 341
 342         if (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
 343             dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL)
 344                 log_debug("Got D-Bus request: %s.%s() on %s",
 345                           dbus_message_get_interface(message),
 346                           dbus_message_get_member(message),
 347                           dbus_message_get_path(message));
 348
 349         if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
 350                 log_debug("API D-Bus connection terminated.");
 351                 bus_done_api(m);
 352
 353         } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
 354                 const char *name, *old_owner, *new_owner;
 355
 356                 if (!dbus_message_get_args(message, &error,
 357                                            DBUS_TYPE_STRING, &name,
 358                                            DBUS_TYPE_STRING, &old_owner,
 359                                            DBUS_TYPE_STRING, &new_owner,
 360                                            DBUS_TYPE_INVALID))
 361                         log_error("Failed to parse NameOwnerChanged message: %s", error.message);
 362                 else  {
 363                         if (set_remove(BUS_CONNECTION_SUBSCRIBED(m, connection), (char*) name))
 364                                 log_debug("Subscription client vanished: %s (left: %u)", name, set_size(BUS_CONNECTION_SUBSCRIBED(m, connection)));
 365
 366                         if (old_owner[0] == 0)
 367                                 old_owner = NULL;
 368
 369                         if (new_owner[0] == 0)
 370                                 new_owner = NULL;
 371
 372                         manager_dispatch_bus_name_owner_changed(m, name, old_owner, new_owner);
 373                 }
 374         } else if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Activator", "ActivationRequest")) {
 375                 const char *name;
 376
 377                 if (!dbus_message_get_args(message, &error,
 378                                            DBUS_TYPE_STRING, &name,
 379                                            DBUS_TYPE_INVALID))
 380                         log_error("Failed to parse ActivationRequest message: %s", error.message);
 381                 else  {
 382                         int r;
 383                         Unit *u;
 384
 385                         log_debug("Got D-Bus activation request for %s", name);
 386
 387                         if (manager_unit_pending_inactive(m, SPECIAL_DBUS_SERVICE) ||
 388                             manager_unit_pending_inactive(m, SPECIAL_DBUS_SOCKET)) {
 389                                 r = -EADDRNOTAVAIL;
 390                                 dbus_set_error(&error, BUS_ERROR_SHUTTING_DOWN, "Refusing activation, D-Bus is shutting down.");
 391                         } else {
 392                                 r = manager_load_unit(m, name, NULL, &error, &u);
 393
 394                                 if (r >= 0 && u->meta.refuse_manual_start)
 395                                         r = -EPERM;
 396
 397                                 if (r >= 0)
 398                                         r = manager_add_job(m, JOB_START, u, JOB_REPLACE, true, &error, NULL);
 399                         }
 400
 401                         if (r < 0) {
 402                                 const char *id, *text;
 403
 404                                 log_debug("D-Bus activation failed for %s: %s", name, strerror(-r));
 405
 406                                 if (!(reply = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Activator", "ActivationFailure")))
 407                                         goto oom;
 408
 409                                 id = error.name ? error.name : bus_errno_to_dbus(r);
 410                                 text = bus_error(&error, r);
 411
 412                                 if (!dbus_message_set_destination(reply, DBUS_SERVICE_DBUS) ||
 413                                     !dbus_message_append_args(reply,
 414                                                               DBUS_TYPE_STRING, &name,
 415                                                               DBUS_TYPE_STRING, &id,
 416                                                               DBUS_TYPE_STRING, &text,
 417                                                               DBUS_TYPE_INVALID))
 418                                         goto oom;
 419                         }
 420
 421                         /* On success we don't do anything, the service will be spawned now */
 422                 }
 423         }
 424
 425         dbus_error_free(&error);
 426
 427         if (reply) {
 428                 if (!dbus_connection_send(connection, reply, NULL))
 429                         goto oom;
 430
 431                 dbus_message_unref(reply);
 432         }
 433
 434         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 435
 436 oom:
 437         if (reply)
 438                 dbus_message_unref(reply);
 439
 440         dbus_error_free(&error);
 441
 442         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 443 }
 444
 445 static DBusHandlerResult system_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
 446         Manager *m = data;
 447         DBusError error;
 448
 449         assert(connection);
 450         assert(message);
 451         assert(m);
 452
 453         dbus_error_init(&error);
 454
 455         if (m->api_bus != m->system_bus &&
 456             (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
 457              dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL))
 458                 log_debug("Got D-Bus request on system bus: %s.%s() on %s",
 459                           dbus_message_get_interface(message),
 460                           dbus_message_get_member(message),
 461                           dbus_message_get_path(message));
 462
 463         if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
 464                 log_debug("System D-Bus connection terminated.");
 465                 bus_done_system(m);
 466
 467         } else if (m->running_as != MANAGER_SYSTEM &&
 468                    dbus_message_is_signal(message, "org.freedesktop.systemd1.Agent", "Released")) {
 469
 470                 const char *cgroup;
 471
 472                 if (!dbus_message_get_args(message, &error,
 473                                            DBUS_TYPE_STRING, &cgroup,
 474                                            DBUS_TYPE_INVALID))
 475                         log_error("Failed to parse Released message: %s", error.message);
 476                 else
 477                         cgroup_notify_empty(m, cgroup);
 478         }
 479
 480         dbus_error_free(&error);
 481         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 482 }
 483
 484 static DBusHandlerResult private_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
 485         Manager *m = data;
 486         DBusError error;
 487
 488         assert(connection);
 489         assert(message);
 490         assert(m);
 491
 492         dbus_error_init(&error);
 493
 494         if (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
 495             dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL)
 496                 log_debug("Got D-Bus request: %s.%s() on %s",
 497                           dbus_message_get_interface(message),
 498                           dbus_message_get_member(message),
 499                           dbus_message_get_path(message));
 500
 501         if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected"))
 502                 shutdown_connection(m, connection);
 503         else if (m->running_as == MANAGER_SYSTEM &&
 504                  dbus_message_is_signal(message, "org.freedesktop.systemd1.Agent", "Released")) {
 505
 506                 const char *cgroup;
 507
 508                 if (!dbus_message_get_args(message, &error,
 509                                            DBUS_TYPE_STRING, &cgroup,
 510                                            DBUS_TYPE_INVALID))
 511                         log_error("Failed to parse Released message: %s", error.message);
 512                 else
 513                         cgroup_notify_empty(m, cgroup);
 514
 515                 /* Forward the message to the system bus, so that user
 516                  * instances are notified as well */
 517
 518                 if (m->system_bus)
 519                         dbus_connection_send(m->system_bus, message, NULL);
 520         }
 521
 522         dbus_error_free(&error);
 523
 524         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 525 }
 526
 527 unsigned bus_dispatch(Manager *m) {
 528         DBusConnection *c;
 529
 530         assert(m);
 531
 532         if (m->queued_message) {
 533                 /* If we cannot get rid of this message we won't
 534                  * dispatch any D-Bus messages, so that we won't end
 535                  * up wanting to queue another message. */
 536
 537                 if (m->queued_message_connection)
 538                         if (!dbus_connection_send(m->queued_message_connection, m->queued_message, NULL))
 539                                 return 0;
 540
 541                 dbus_message_unref(m->queued_message);
 542                 m->queued_message = NULL;
 543                 m->queued_message_connection = NULL;
 544         }
 545
 546         if ((c = set_first(m->bus_connections_for_dispatch))) {
 547                 if (dbus_connection_dispatch(c) == DBUS_DISPATCH_COMPLETE)
 548                         set_move_one(m->bus_connections, m->bus_connections_for_dispatch, c);
 549
 550                 return 1;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static void request_name_pending_cb(DBusPendingCall *pending, void *userdata) {
 557         DBusMessage *reply;
 558         DBusError error;
 559
 560         dbus_error_init(&error);
 561
 562         assert_se(reply = dbus_pending_call_steal_reply(pending));
 563
 564         switch (dbus_message_get_type(reply)) {
 565
 566         case DBUS_MESSAGE_TYPE_ERROR:
 567
 568                 assert_se(dbus_set_error_from_message(&error, reply));
 569                 log_warning("RequestName() failed: %s", error.message);
 570                 break;
 571
 572         case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
 573                 uint32_t r;
 574
 575                 if (!dbus_message_get_args(reply,
 576                                            &error,
 577                                            DBUS_TYPE_UINT32, &r,
 578                                            DBUS_TYPE_INVALID)) {
 579                         log_error("Failed to parse RequestName() reply: %s", error.message);
 580                         break;
 581                 }
 582
 583                 if (r == 1)
 584                         log_debug("Successfully acquired name.");
 585                 else
 586                         log_error("Name already owned.");
 587
 588                 break;
 589         }
 590
 591         default:
 592                 assert_not_reached("Invalid reply message");
 593         }
 594
 595         dbus_message_unref(reply);
 596         dbus_error_free(&error);
 597 }
 598
 599 static int request_name(Manager *m) {
 600         const char *name = "org.freedesktop.systemd1";
 601         /* Allow replacing of our name, to ease implementation of
 602          * reexecution, where we keep the old connection open until
 603          * after the new connection is set up and the name installed
 604          * to allow clients to synchronously wait for reexecution to
 605          * finish */
 606         uint32_t flags = DBUS_NAME_FLAG_ALLOW_REPLACEMENT|DBUS_NAME_FLAG_REPLACE_EXISTING;
 607         DBusMessage *message = NULL;
 608         DBusPendingCall *pending = NULL;
 609
 610         if (!(message = dbus_message_new_method_call(
 611                               DBUS_SERVICE_DBUS,
 612                               DBUS_PATH_DBUS,
 613                               DBUS_INTERFACE_DBUS,
 614                               "RequestName")))
 615                 goto oom;
 616
 617         if (!dbus_message_append_args(
 618                             message,
 619                             DBUS_TYPE_STRING, &name,
 620                             DBUS_TYPE_UINT32, &flags,
 621                             DBUS_TYPE_INVALID))
 622                 goto oom;
 623
 624         if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
 625                 goto oom;
 626
 627         if (!dbus_pending_call_set_notify(pending, request_name_pending_cb, m, NULL))
 628                 goto oom;
 629
 630         dbus_message_unref(message);
 631         dbus_pending_call_unref(pending);
 632
 633         /* We simple ask for the name and don't wait for it. Sooner or
 634          * later we'll have it. */
 635
 636         return 0;
 637
 638 oom:
 639         if (pending) {
 640                 dbus_pending_call_cancel(pending);
 641                 dbus_pending_call_unref(pending);
 642         }
 643
 644         if (message)
 645                 dbus_message_unref(message);
 646
 647         return -ENOMEM;
 648 }
 649
 650 static void query_name_list_pending_cb(DBusPendingCall *pending, void *userdata) {
 651         DBusMessage *reply;
 652         DBusError error;
 653         Manager *m = userdata;
 654
 655         assert(m);
 656
 657         dbus_error_init(&error);
 658
 659         assert_se(reply = dbus_pending_call_steal_reply(pending));
 660
 661         switch (dbus_message_get_type(reply)) {
 662
 663         case DBUS_MESSAGE_TYPE_ERROR:
 664
 665                 assert_se(dbus_set_error_from_message(&error, reply));
 666                 log_warning("ListNames() failed: %s", error.message);
 667                 break;
 668
 669         case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
 670                 int r;
 671                 char **l;
 672
 673                 if ((r = bus_parse_strv(reply, &l)) < 0)
 674                         log_warning("Failed to parse ListNames() reply: %s", strerror(-r));
 675                 else {
 676                         char **t;
 677
 678                         STRV_FOREACH(t, l)
 679                                 /* This is a bit hacky, we say the
 680                                  * owner of the name is the name
 681                                  * itself, because we don't want the
 682                                  * extra traffic to figure out the
 683                                  * real owner. */
 684                                 manager_dispatch_bus_name_owner_changed(m, *t, NULL, *t);
 685
 686                         strv_free(l);
 687                 }
 688
 689                 break;
 690         }
 691
 692         default:
 693                 assert_not_reached("Invalid reply message");
 694         }
 695
 696         dbus_message_unref(reply);
 697         dbus_error_free(&error);
 698 }
 699
 700 static int query_name_list(Manager *m) {
 701         DBusMessage *message = NULL;
 702         DBusPendingCall *pending = NULL;
 703
 704         /* Asks for the currently installed bus names */
 705
 706         if (!(message = dbus_message_new_method_call(
 707                               DBUS_SERVICE_DBUS,
 708                               DBUS_PATH_DBUS,
 709                               DBUS_INTERFACE_DBUS,
 710                               "ListNames")))
 711                 goto oom;
 712
 713         if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
 714                 goto oom;
 715
 716         if (!dbus_pending_call_set_notify(pending, query_name_list_pending_cb, m, NULL))
 717                 goto oom;
 718
 719         dbus_message_unref(message);
 720         dbus_pending_call_unref(pending);
 721
 722         /* We simple ask for the list and don't wait for it. Sooner or
 723          * later we'll get it. */
 724
 725         return 0;
 726
 727 oom:
 728         if (pending) {
 729                 dbus_pending_call_cancel(pending);
 730                 dbus_pending_call_unref(pending);
 731         }
 732
 733         if (message)
 734                 dbus_message_unref(message);
 735
 736         return -ENOMEM;
 737 }
 738
 739 static int bus_setup_loop(Manager *m, DBusConnection *bus) {
 740         assert(m);
 741         assert(bus);
 742
 743         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 744
 745         if (!dbus_connection_set_watch_functions(bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
 746             !dbus_connection_set_timeout_functions(bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL)) {
 747                 log_error("Not enough memory");
 748                 return -ENOMEM;
 749         }
 750
 751         if (set_put(m->bus_connections_for_dispatch, bus) < 0) {
 752                 log_error("Not enough memory");
 753                 return -ENOMEM;
 754         }
 755
 756         dbus_connection_set_dispatch_status_function(bus, bus_dispatch_status, m, NULL);
 757         return 0;
 758 }
 759
 760 static dbus_bool_t allow_only_root(DBusConnection *connection, unsigned long uid, void *data) {
 761         return uid == 0;
 762 }
 763
 764 static void bus_new_connection(
 765                 DBusServer *server,
 766                 DBusConnection *new_connection,
 767                 void *data) {
 768
 769         Manager *m = data;
 770
 771         assert(m);
 772
 773         if (set_size(m->bus_connections) >= CONNECTIONS_MAX) {
 774                 log_error("Too many concurrent connections.");
 775                 return;
 776         }
 777
 778         dbus_connection_set_unix_user_function(new_connection, allow_only_root, NULL, NULL);
 779
 780         if (bus_setup_loop(m, new_connection) < 0)
 781                 return;
 782
 783         if (!dbus_connection_register_object_path(new_connection, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
 784             !dbus_connection_register_fallback(new_connection, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
 785             !dbus_connection_register_fallback(new_connection, "/org/freedesktop/systemd1/job", &bus_job_vtable, m) ||
 786             !dbus_connection_add_filter(new_connection, private_bus_message_filter, m, NULL)) {
 787                 log_error("Not enough memory.");
 788                 return;
 789         }
 790
 791         log_debug("Accepted connection on private bus.");
 792
 793         dbus_connection_ref(new_connection);
 794 }
 795
 796 static int bus_init_system(Manager *m) {
 797         DBusError error;
 798         int r;
 799
 800         assert(m);
 801
 802         dbus_error_init(&error);
 803
 804         if (m->system_bus)
 805                 return 0;
 806
 807         if (m->running_as == MANAGER_SYSTEM && m->api_bus)
 808                 m->system_bus = m->api_bus;
 809         else {
 810                 if (!(m->system_bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error))) {
 811                         log_debug("Failed to get system D-Bus connection, retrying later: %s", error.message);
 812                         r = 0;
 813                         goto fail;
 814                 }
 815
 816                 if ((r = bus_setup_loop(m, m->system_bus)) < 0)
 817                         goto fail;
 818         }
 819
 820         if (!dbus_connection_add_filter(m->system_bus, system_bus_message_filter, m, NULL)) {
 821                 log_error("Not enough memory");
 822                 r = -EIO;
 823                 goto fail;
 824         }
 825
 826         if (m->running_as != MANAGER_SYSTEM) {
 827                 dbus_bus_add_match(m->system_bus,
 828                                    "type='signal',"
 829                                    "interface='org.freedesktop.systemd1.Agent',"
 830                                    "member='Released',"
 831                                    "path='/org/freedesktop/systemd1/agent'",
 832                                    &error);
 833
 834                 if (dbus_error_is_set(&error)) {
 835                         log_error("Failed to register match: %s", error.message);
 836                         r = -EIO;
 837                         goto fail;
 838                 }
 839         }
 840
 841         if (m->api_bus != m->system_bus) {
 842                 char *id;
 843                 log_debug("Successfully connected to system D-Bus bus %s as %s",
 844                          strnull((id = dbus_connection_get_server_id(m->system_bus))),
 845                          strnull(dbus_bus_get_unique_name(m->system_bus)));
 846                 dbus_free(id);
 847         }
 848
 849         return 0;
 850
 851 fail:
 852         bus_done_system(m);
 853         dbus_error_free(&error);
 854
 855         return r;
 856 }
 857
 858 static int bus_init_api(Manager *m) {
 859         DBusError error;
 860         int r;
 861
 862         assert(m);
 863
 864         dbus_error_init(&error);
 865
 866         if (m->api_bus)
 867                 return 0;
 868
 869         if (m->running_as == MANAGER_SYSTEM && m->system_bus)
 870                 m->api_bus = m->system_bus;
 871         else {
 872                 if (!(m->api_bus = dbus_bus_get_private(m->running_as == MANAGER_USER ? DBUS_BUS_SESSION : DBUS_BUS_SYSTEM, &error))) {
 873                         log_debug("Failed to get API D-Bus connection, retrying later: %s", error.message);
 874                         r = 0;
 875                         goto fail;
 876                 }
 877
 878                 if ((r = bus_setup_loop(m, m->api_bus)) < 0)
 879                         goto fail;
 880         }
 881
 882         if (!dbus_connection_register_object_path(m->api_bus, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
 883             !dbus_connection_register_fallback(m->api_bus, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
 884             !dbus_connection_register_fallback(m->api_bus, "/org/freedesktop/systemd1/job", &bus_job_vtable, m) ||
 885             !dbus_connection_add_filter(m->api_bus, api_bus_message_filter, m, NULL)) {
 886                 log_error("Not enough memory");
 887                 r = -ENOMEM;
 888                 goto fail;
 889         }
 890
 891         /* Get NameOwnerChange messages */
 892         dbus_bus_add_match(m->api_bus,
 893                            "type='signal',"
 894                            "sender='"DBUS_SERVICE_DBUS"',"
 895                            "interface='"DBUS_INTERFACE_DBUS"',"
 896                            "member='NameOwnerChanged',"
 897                            "path='"DBUS_PATH_DBUS"'",
 898                            &error);
 899
 900         if (dbus_error_is_set(&error)) {
 901                 log_error("Failed to register match: %s", error.message);
 902                 r = -EIO;
 903                 goto fail;
 904         }
 905
 906         /* Get activation requests */
 907         dbus_bus_add_match(m->api_bus,
 908                            "type='signal',"
 909                            "sender='"DBUS_SERVICE_DBUS"',"
 910                            "interface='org.freedesktop.systemd1.Activator',"
 911                            "member='ActivationRequest',"
 912                            "path='"DBUS_PATH_DBUS"'",
 913                            &error);
 914
 915         if (dbus_error_is_set(&error)) {
 916                 log_error("Failed to register match: %s", error.message);
 917                 r = -EIO;
 918                 goto fail;
 919         }
 920
 921         if ((r = request_name(m)) < 0)
 922                 goto fail;
 923
 924         if ((r = query_name_list(m)) < 0)
 925                 goto fail;
 926
 927         if (m->api_bus != m->system_bus) {
 928                 char *id;
 929                 log_debug("Successfully connected to API D-Bus bus %s as %s",
 930                          strnull((id = dbus_connection_get_server_id(m->api_bus))),
 931                          strnull(dbus_bus_get_unique_name(m->api_bus)));
 932                 dbus_free(id);
 933         }
 934
 935         return 0;
 936
 937 fail:
 938         bus_done_api(m);
 939         dbus_error_free(&error);
 940
 941         return r;
 942 }
 943
 944 static int bus_init_private(Manager *m) {
 945         DBusError error;
 946         int r;
 947         const char *const external_only[] = {
 948                 "EXTERNAL",
 949                 NULL
 950         };
 951
 952         assert(m);
 953
 954         dbus_error_init(&error);
 955
 956         if (m->private_bus)
 957                 return 0;
 958
 959         /* We want the private bus only when running as init */
 960         if (getpid() != 1)
 961                 return 0;
 962
 963         unlink("/run/systemd/private");
 964         if (!(m->private_bus = dbus_server_listen("unix:path=/run/systemd/private", &error))) {
 965                 log_error("Failed to create private D-Bus server: %s", error.message);
 966                 r = -EIO;
 967                 goto fail;
 968         }
 969
 970         if (!dbus_server_set_auth_mechanisms(m->private_bus, (const char**) external_only) ||
 971             !dbus_server_set_watch_functions(m->private_bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
 972             !dbus_server_set_timeout_functions(m->private_bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL)) {
 973                 log_error("Not enough memory");
 974                 r = -ENOMEM;
 975                 goto fail;
 976         }
 977
 978         dbus_server_set_new_connection_function(m->private_bus, bus_new_connection, m, NULL);
 979
 980         log_debug("Successfully created private D-Bus server.");
 981
 982         return 0;
 983
 984 fail:
 985         bus_done_private(m);
 986         dbus_error_free(&error);
 987
 988         return r;
 989 }
 990
 991 int bus_init(Manager *m, bool try_bus_connect) {
 992         int r;
 993
 994         if (set_ensure_allocated(&m->bus_connections, trivial_hash_func, trivial_compare_func) < 0 ||
 995             set_ensure_allocated(&m->bus_connections_for_dispatch, trivial_hash_func, trivial_compare_func) < 0) {
 996                 log_error("Not enough memory");
 997                 return -ENOMEM;
 998         }
 999
1000         if (m->name_data_slot < 0)
1001                 if (!dbus_pending_call_allocate_data_slot(&m->name_data_slot)) {
1002                         log_error("Not enough memory");
1003                         return -ENOMEM;
1004                 }
1005
1006         if (m->subscribed_data_slot < 0)
1007                 if (!dbus_connection_allocate_data_slot(&m->subscribed_data_slot)) {
1008                         log_error("Not enough memory");
1009                         return -ENOMEM;
1010                 }
1011
1012         if (try_bus_connect) {
1013                 if ((r = bus_init_system(m)) < 0 ||
1014                     (r = bus_init_api(m)) < 0)
1015                         return r;
1016         }
1017
1018         if ((r = bus_init_private(m)) < 0)
1019                 return r;
1020
1021         return 0;
1022 }
1023
1024 static void shutdown_connection(Manager *m, DBusConnection *c) {
1025         Set *s;
1026         Job *j;
1027         Iterator i;
1028
1029         HASHMAP_FOREACH(j, m->jobs, i)
1030                 if (j->bus == c) {
1031                         free(j->bus_client);
1032                         j->bus_client = NULL;
1033
1034                         j->bus = NULL;
1035                 }
1036
1037         set_remove(m->bus_connections, c);
1038         set_remove(m->bus_connections_for_dispatch, c);
1039
1040         if ((s = BUS_CONNECTION_SUBSCRIBED(m, c))) {
1041                 char *t;
1042
1043                 while ((t = set_steal_first(s)))
1044                         free(t);
1045
1046                 set_free(s);
1047         }
1048
1049         if (m->queued_message_connection == c) {
1050                 m->queued_message_connection = NULL;
1051
1052                 if (m->queued_message) {
1053                         dbus_message_unref(m->queued_message);
1054                         m->queued_message = NULL;
1055                 }
1056         }
1057
1058         dbus_connection_set_dispatch_status_function(c, NULL, NULL, NULL);
1059         dbus_connection_flush(c);
1060         dbus_connection_close(c);
1061         dbus_connection_unref(c);
1062 }
1063
1064 static void bus_done_api(Manager *m) {
1065         assert(m);
1066
1067         if (m->api_bus) {
1068                 if (m->system_bus == m->api_bus)
1069                         m->system_bus = NULL;
1070
1071                 shutdown_connection(m, m->api_bus);
1072                 m->api_bus = NULL;
1073         }
1074
1075
1076        if (m->queued_message) {
1077                dbus_message_unref(m->queued_message);
1078                m->queued_message = NULL;
1079        }
1080 }
1081
1082 static void bus_done_system(Manager *m) {
1083         assert(m);
1084
1085         if (m->system_bus == m->api_bus)
1086                 bus_done_api(m);
1087
1088         if (m->system_bus) {
1089                 shutdown_connection(m, m->system_bus);
1090                 m->system_bus = NULL;
1091         }
1092 }
1093
1094 static void bus_done_private(Manager *m) {
1095
1096         if (m->private_bus) {
1097                 dbus_server_disconnect(m->private_bus);
1098                 dbus_server_unref(m->private_bus);
1099                 m->private_bus = NULL;
1100         }
1101 }
1102
1103 void bus_done(Manager *m) {
1104         DBusConnection *c;
1105
1106         bus_done_api(m);
1107         bus_done_system(m);
1108         bus_done_private(m);
1109
1110         while ((c = set_steal_first(m->bus_connections)))
1111                 shutdown_connection(m, c);
1112
1113         while ((c = set_steal_first(m->bus_connections_for_dispatch)))
1114                 shutdown_connection(m, c);
1115
1116         set_free(m->bus_connections);
1117         set_free(m->bus_connections_for_dispatch);
1118
1119         if (m->name_data_slot >= 0)
1120                dbus_pending_call_free_data_slot(&m->name_data_slot);
1121
1122         if (m->subscribed_data_slot >= 0)
1123                 dbus_connection_free_data_slot(&m->subscribed_data_slot);
1124 }
1125
1126 static void query_pid_pending_cb(DBusPendingCall *pending, void *userdata) {
1127         Manager *m = userdata;
1128         DBusMessage *reply;
1129         DBusError error;
1130         const char *name;
1131
1132         dbus_error_init(&error);
1133
1134         assert_se(name = BUS_PENDING_CALL_NAME(m, pending));
1135         assert_se(reply = dbus_pending_call_steal_reply(pending));
1136
1137         switch (dbus_message_get_type(reply)) {
1138
1139         case DBUS_MESSAGE_TYPE_ERROR:
1140
1141                 assert_se(dbus_set_error_from_message(&error, reply));
1142                 log_warning("GetConnectionUnixProcessID() failed: %s", error.message);
1143                 break;
1144
1145         case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
1146                 uint32_t r;
1147
1148                 if (!dbus_message_get_args(reply,
1149                                            &error,
1150                                            DBUS_TYPE_UINT32, &r,
1151                                            DBUS_TYPE_INVALID)) {
1152                         log_error("Failed to parse GetConnectionUnixProcessID() reply: %s", error.message);
1153                         break;
1154                 }
1155
1156                 manager_dispatch_bus_query_pid_done(m, name, (pid_t) r);
1157                 break;
1158         }
1159
1160         default:
1161                 assert_not_reached("Invalid reply message");
1162         }
1163
1164         dbus_message_unref(reply);
1165         dbus_error_free(&error);
1166 }
1167
1168 int bus_query_pid(Manager *m, const char *name) {
1169         DBusMessage *message = NULL;
1170         DBusPendingCall *pending = NULL;
1171         char *n = NULL;
1172
1173         assert(m);
1174         assert(name);
1175
1176         if (!(message = dbus_message_new_method_call(
1177                               DBUS_SERVICE_DBUS,
1178                               DBUS_PATH_DBUS,
1179                               DBUS_INTERFACE_DBUS,
1180                               "GetConnectionUnixProcessID")))
1181                 goto oom;
1182
1183         if (!(dbus_message_append_args(
1184                               message,
1185                               DBUS_TYPE_STRING, &name,
1186                               DBUS_TYPE_INVALID)))
1187                 goto oom;
1188
1189         if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
1190                 goto oom;
1191
1192         if (!(n = strdup(name)))
1193                 goto oom;
1194
1195         if (!dbus_pending_call_set_data(pending, m->name_data_slot, n, free))
1196                 goto oom;
1197
1198         n = NULL;
1199
1200         if (!dbus_pending_call_set_notify(pending, query_pid_pending_cb, m, NULL))
1201                 goto oom;
1202
1203         dbus_message_unref(message);
1204         dbus_pending_call_unref(pending);
1205
1206         return 0;
1207
1208 oom:
1209         free(n);
1210
1211         if (pending) {
1212                 dbus_pending_call_cancel(pending);
1213                 dbus_pending_call_unref(pending);
1214         }
1215
1216         if (message)
1217                 dbus_message_unref(message);
1218
1219         return -ENOMEM;
1220 }
1221
1222 int bus_broadcast(Manager *m, DBusMessage *message) {
1223         bool oom = false;
1224         Iterator i;
1225         DBusConnection *c;
1226
1227         assert(m);
1228         assert(message);
1229
1230         SET_FOREACH(c, m->bus_connections_for_dispatch, i)
1231                 if (c != m->system_bus || m->running_as == MANAGER_SYSTEM)
1232                         oom = !dbus_connection_send(c, message, NULL);
1233
1234         SET_FOREACH(c, m->bus_connections, i)
1235                 if (c != m->system_bus || m->running_as == MANAGER_SYSTEM)
1236                         oom = !dbus_connection_send(c, message, NULL);
1237
1238         return oom ? -ENOMEM : 0;
1239 }
1240
1241 int bus_parse_strv(DBusMessage *m, char ***_l) {
1242         DBusMessageIter iter, sub;
1243         unsigned n = 0, i = 0;
1244         char **l;
1245
1246         assert(m);
1247         assert(_l);
1248
1249         if (!dbus_message_iter_init(m, &iter) ||
1250             dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
1251             dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRING)
1252             return -EINVAL;
1253
1254         dbus_message_iter_recurse(&iter, &sub);
1255
1256         while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
1257                 n++;
1258                 dbus_message_iter_next(&sub);
1259         }
1260
1261         if (!(l = new(char*, n+1)))
1262                 return -ENOMEM;
1263
1264         assert_se(dbus_message_iter_init(m, &iter));
1265         dbus_message_iter_recurse(&iter, &sub);
1266
1267         while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
1268                 const char *s;
1269
1270                 assert_se(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
1271                 dbus_message_iter_get_basic(&sub, &s);
1272
1273                 if (!(l[i++] = strdup(s))) {
1274                         strv_free(l);
1275                         return -ENOMEM;
1276                 }
1277
1278                 dbus_message_iter_next(&sub);
1279         }
1280
1281         assert(i == n);
1282         l[i] = NULL;
1283
1284         if (_l)
1285                 *_l = l;
1286
1287         return 0;
1288 }
1289
1290 bool bus_has_subscriber(Manager *m) {
1291         Iterator i;
1292         DBusConnection *c;
1293
1294         assert(m);
1295
1296         SET_FOREACH(c, m->bus_connections_for_dispatch, i)
1297                 if (bus_connection_has_subscriber(m, c))
1298                         return true;
1299
1300         SET_FOREACH(c, m->bus_connections, i)
1301                 if (bus_connection_has_subscriber(m, c))
1302                         return true;
1303
1304         return false;
1305 }
1306
1307 bool bus_connection_has_subscriber(Manager *m, DBusConnection *c) {
1308         assert(m);
1309         assert(c);
1310
1311         return !set_isempty(BUS_CONNECTION_SUBSCRIBED(m, c));
1312 }
1313
1314 int bus_fdset_add_all(Manager *m, FDSet *fds) {
1315         Iterator i;
1316         DBusConnection *c;
1317
1318         assert(m);
1319         assert(fds);
1320
1321         /* When we are about to reexecute we add all D-Bus fds to the
1322          * set to pass over to the newly executed systemd. They won't
1323          * be used there however, except that they are closed at the
1324          * very end of deserialization, those making it possible for
1325          * clients to synchronously wait for systemd to reexec buy
1326          * simply waiting for disconnection */
1327
1328         SET_FOREACH(c, m->bus_connections_for_dispatch, i) {
1329                 int fd;
1330
1331                 if (dbus_connection_get_unix_fd(c, &fd)) {
1332                         fd = fdset_put_dup(fds, fd);
1333
1334                         if (fd < 0)
1335                                 return fd;
1336                 }
1337         }
1338
1339         SET_FOREACH(c, m->bus_connections, i) {
1340                 int fd;
1341
1342                 if (dbus_connection_get_unix_fd(c, &fd)) {
1343                         fd = fdset_put_dup(fds, fd);
1344
1345                         if (fd < 0)
1346                                 return fd;
1347                 }
1348         }
1349
1350         return 0;
1351 }