src/dbus-unit.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 <errno.h>
  23
  24 #include "dbus.h"
  25 #include "log.h"
  26 #include "dbus-unit.h"
  27 #include "bus-errors.h"
  28
  29 const char bus_unit_interface[] = BUS_UNIT_INTERFACE;
  30
  31 #define INVALIDATING_PROPERTIES                 \
  32         "LoadState\0"                           \
  33         "ActiveState\0"                         \
  34         "SubState\0"                            \
  35         "InactiveExitTimestamp\0"               \
  36         "ActiveEnterTimestamp\0"                \
  37         "ActiveExitTimestamp\0"                 \
  38         "InactiveEnterTimestamp\0"              \
  39         "Job\0"                                 \
  40         "NeedDaemonReload\0"                    \
  41         "\0"
  42
  43 int bus_unit_append_names(Manager *m, DBusMessageIter *i, const char *property, void *data) {
  44         char *t;
  45         Iterator j;
  46         DBusMessageIter sub;
  47         Unit *u = data;
  48
  49         if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub))
  50                 return -ENOMEM;
  51
  52         SET_FOREACH(t, u->meta.names, j)
  53                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &t))
  54                         return -ENOMEM;
  55
  56         if (!dbus_message_iter_close_container(i, &sub))
  57                 return -ENOMEM;
  58
  59         return 0;
  60 }
  61
  62 int bus_unit_append_following(Manager *m, DBusMessageIter *i, const char *property, void *data) {
  63         Unit *u = data, *f;
  64         const char *d;
  65
  66         assert(m);
  67         assert(i);
  68         assert(property);
  69         assert(u);
  70
  71         f = unit_following(u);
  72         d = f ? f->meta.id : "";
  73
  74         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &d))
  75                 return -ENOMEM;
  76
  77         return 0;
  78 }
  79
  80 int bus_unit_append_dependencies(Manager *m, DBusMessageIter *i, const char *property, void *data) {
  81         Unit *u;
  82         Iterator j;
  83         DBusMessageIter sub;
  84         Set *s = data;
  85
  86         if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub))
  87                 return -ENOMEM;
  88
  89         SET_FOREACH(u, s, j)
  90                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &u->meta.id))
  91                         return -ENOMEM;
  92
  93         if (!dbus_message_iter_close_container(i, &sub))
  94                 return -ENOMEM;
  95
  96         return 0;
  97 }
  98
  99 int bus_unit_append_description(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 100         Unit *u = data;
 101         const char *d;
 102
 103         assert(m);
 104         assert(i);
 105         assert(property);
 106         assert(u);
 107
 108         d = unit_description(u);
 109
 110         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &d))
 111                 return -ENOMEM;
 112
 113         return 0;
 114 }
 115
 116 DEFINE_BUS_PROPERTY_APPEND_ENUM(bus_unit_append_load_state, unit_load_state, UnitLoadState);
 117
 118 int bus_unit_append_active_state(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 119         Unit *u = data;
 120         const char *state;
 121
 122         assert(m);
 123         assert(i);
 124         assert(property);
 125         assert(u);
 126
 127         state = unit_active_state_to_string(unit_active_state(u));
 128
 129         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &state))
 130                 return -ENOMEM;
 131
 132         return 0;
 133 }
 134
 135 int bus_unit_append_sub_state(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 136         Unit *u = data;
 137         const char *state;
 138
 139         assert(m);
 140         assert(i);
 141         assert(property);
 142         assert(u);
 143
 144         state = unit_sub_state_to_string(u);
 145
 146         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &state))
 147                 return -ENOMEM;
 148
 149         return 0;
 150 }
 151
 152 int bus_unit_append_can_start(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 153         Unit *u = data;
 154         dbus_bool_t b;
 155
 156         assert(m);
 157         assert(i);
 158         assert(property);
 159         assert(u);
 160
 161         b = unit_can_start(u) &&
 162                 !u->meta.refuse_manual_start;
 163
 164         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &b))
 165                 return -ENOMEM;
 166
 167         return 0;
 168 }
 169
 170 int bus_unit_append_can_stop(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 171         Unit *u = data;
 172         dbus_bool_t b;
 173
 174         assert(m);
 175         assert(i);
 176         assert(property);
 177         assert(u);
 178
 179         /* On the lower levels we assume that every unit we can start
 180          * we can also stop */
 181
 182         b = unit_can_start(u) &&
 183                 !u->meta.refuse_manual_stop;
 184
 185         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &b))
 186                 return -ENOMEM;
 187
 188         return 0;
 189 }
 190
 191 int bus_unit_append_can_reload(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 192         Unit *u = data;
 193         dbus_bool_t b;
 194
 195         assert(m);
 196         assert(i);
 197         assert(property);
 198         assert(u);
 199
 200         b = unit_can_reload(u);
 201
 202         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &b))
 203                 return -ENOMEM;
 204
 205         return 0;
 206 }
 207
 208 int bus_unit_append_can_isolate(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 209         Unit *u = data;
 210         dbus_bool_t b;
 211
 212         assert(m);
 213         assert(i);
 214         assert(property);
 215         assert(u);
 216
 217         b = unit_can_isolate(u) &&
 218                 !u->meta.refuse_manual_start;
 219
 220         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &b))
 221                 return -ENOMEM;
 222
 223         return 0;
 224 }
 225
 226 int bus_unit_append_job(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 227         Unit *u = data;
 228         DBusMessageIter sub;
 229         char *p;
 230
 231         assert(m);
 232         assert(i);
 233         assert(property);
 234         assert(u);
 235
 236         if (!dbus_message_iter_open_container(i, DBUS_TYPE_STRUCT, NULL, &sub))
 237                 return -ENOMEM;
 238
 239         if (u->meta.job) {
 240
 241                 if (!(p = job_dbus_path(u->meta.job)))
 242                         return -ENOMEM;
 243
 244                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_UINT32, &u->meta.job->id) ||
 245                     !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p)) {
 246                         free(p);
 247                         return -ENOMEM;
 248                 }
 249         } else {
 250                 uint32_t id = 0;
 251
 252                 /* No job, so let's fill in some placeholder
 253                  * data. Since we need to fill in a valid path we
 254                  * simple point to ourselves. */
 255
 256                 if (!(p = unit_dbus_path(u)))
 257                         return -ENOMEM;
 258
 259                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_UINT32, &id) ||
 260                     !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p)) {
 261                         free(p);
 262                         return -ENOMEM;
 263                 }
 264         }
 265
 266         free(p);
 267
 268         if (!dbus_message_iter_close_container(i, &sub))
 269                 return -ENOMEM;
 270
 271         return 0;
 272 }
 273
 274 int bus_unit_append_default_cgroup(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 275         Unit *u = data;
 276         char *t;
 277         CGroupBonding *cgb;
 278         bool success;
 279
 280         assert(m);
 281         assert(i);
 282         assert(property);
 283         assert(u);
 284
 285         if ((cgb = unit_get_default_cgroup(u))) {
 286                 if (!(t = cgroup_bonding_to_string(cgb)))
 287                         return -ENOMEM;
 288         } else
 289                 t = (char*) "";
 290
 291         success = dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &t);
 292
 293         if (cgb)
 294                 free(t);
 295
 296         return success ? 0 : -ENOMEM;
 297 }
 298
 299 int bus_unit_append_cgroups(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 300         Unit *u = data;
 301         CGroupBonding *cgb;
 302         DBusMessageIter sub;
 303
 304         if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub))
 305                 return -ENOMEM;
 306
 307         LIST_FOREACH(by_unit, cgb, u->meta.cgroup_bondings) {
 308                 char *t;
 309                 bool success;
 310
 311                 if (!(t = cgroup_bonding_to_string(cgb)))
 312                         return -ENOMEM;
 313
 314                 success = dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &t);
 315                 free(t);
 316
 317                 if (!success)
 318                         return -ENOMEM;
 319         }
 320
 321         if (!dbus_message_iter_close_container(i, &sub))
 322                 return -ENOMEM;
 323
 324         return 0;
 325 }
 326
 327 int bus_unit_append_need_daemon_reload(Manager *m, DBusMessageIter *i, const char *property, void *data) {
 328         Unit *u = data;
 329         dbus_bool_t b;
 330
 331         assert(m);
 332         assert(i);
 333         assert(property);
 334         assert(u);
 335
 336         b = unit_need_daemon_reload(u);
 337
 338         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &b))
 339                 return -ENOMEM;
 340
 341         return 0;
 342 }
 343
 344 static DBusHandlerResult bus_unit_message_dispatch(Unit *u, DBusConnection *connection, DBusMessage *message) {
 345         DBusMessage *reply = NULL;
 346         Manager *m = u->meta.manager;
 347         DBusError error;
 348         JobType job_type = _JOB_TYPE_INVALID;
 349         char *path = NULL;
 350         bool reload_if_possible = false;
 351
 352         dbus_error_init(&error);
 353
 354         if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "Start"))
 355                 job_type = JOB_START;
 356         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "Stop"))
 357                 job_type = JOB_STOP;
 358         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "Reload"))
 359                 job_type = JOB_RELOAD;
 360         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "Restart"))
 361                 job_type = JOB_RESTART;
 362         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "TryRestart"))
 363                 job_type = JOB_TRY_RESTART;
 364         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "ReloadOrRestart")) {
 365                 reload_if_possible = true;
 366                 job_type = JOB_RESTART;
 367         } else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "ReloadOrTryRestart")) {
 368                 reload_if_possible = true;
 369                 job_type = JOB_TRY_RESTART;
 370         } else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "Kill")) {
 371                 const char *swho, *smode;
 372                 int32_t signo;
 373                 KillMode mode;
 374                 KillWho who;
 375                 int r;
 376
 377                 if (!dbus_message_get_args(
 378                                     message,
 379                                     &error,
 380                                     DBUS_TYPE_STRING, &swho,
 381                                     DBUS_TYPE_STRING, &smode,
 382                                     DBUS_TYPE_INT32, &signo,
 383                                     DBUS_TYPE_INVALID))
 384                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
 385
 386                 if ((mode = kill_mode_from_string(smode)) < 0 ||
 387                     (who = kill_who_from_string(swho)) < 0 ||
 388                     signo <= 0 ||
 389                     signo >= _NSIG)
 390                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
 391
 392                 if ((r = unit_kill(u, who, mode, signo, &error)) < 0)
 393                         return bus_send_error_reply(m, connection, message, &error, r);
 394
 395                 if (!(reply = dbus_message_new_method_return(message)))
 396                         goto oom;
 397
 398         } else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Unit", "ResetFailed")) {
 399
 400                 unit_reset_failed(u);
 401
 402                 if (!(reply = dbus_message_new_method_return(message)))
 403                         goto oom;
 404
 405         } else if (UNIT_VTABLE(u)->bus_message_handler)
 406                 return UNIT_VTABLE(u)->bus_message_handler(u, connection, message);
 407         else
 408                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 409
 410         if (job_type != _JOB_TYPE_INVALID) {
 411                 const char *smode;
 412                 JobMode mode;
 413                 Job *j;
 414                 int r;
 415
 416                 if ((job_type == JOB_START && u->meta.refuse_manual_start) ||
 417                     (job_type == JOB_STOP && u->meta.refuse_manual_stop) ||
 418                     ((job_type == JOB_RESTART || job_type == JOB_TRY_RESTART) &&
 419                      (u->meta.refuse_manual_start || u->meta.refuse_manual_stop))) {
 420                         dbus_set_error(&error, BUS_ERROR_ONLY_BY_DEPENDENCY, "Operation refused, may be requested by dependency only.");
 421                         return bus_send_error_reply(m, connection, message, &error, -EPERM);
 422                 }
 423
 424                 if (!dbus_message_get_args(
 425                                     message,
 426                                     &error,
 427                                     DBUS_TYPE_STRING, &smode,
 428                                     DBUS_TYPE_INVALID))
 429                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
 430
 431                 if (reload_if_possible && unit_can_reload(u)) {
 432                         if (job_type == JOB_RESTART)
 433                                 job_type = JOB_RELOAD_OR_START;
 434                         else if (job_type == JOB_TRY_RESTART)
 435                                 job_type = JOB_RELOAD;
 436                 }
 437
 438                 if ((mode = job_mode_from_string(smode)) == _JOB_MODE_INVALID) {
 439                         dbus_set_error(&error, BUS_ERROR_INVALID_JOB_MODE, "Job mode %s is invalid.", smode);
 440                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
 441                 }
 442
 443                 if ((r = manager_add_job(m, job_type, u, mode, true, &error, &j)) < 0)
 444                         return bus_send_error_reply(m, connection, message, &error, r);
 445
 446                 if (!(reply = dbus_message_new_method_return(message)))
 447                         goto oom;
 448
 449                 if (!(path = job_dbus_path(j)))
 450                         goto oom;
 451
 452                 if (!dbus_message_append_args(
 453                                     reply,
 454                                     DBUS_TYPE_OBJECT_PATH, &path,
 455                                     DBUS_TYPE_INVALID))
 456                         goto oom;
 457         }
 458
 459         free(path);
 460
 461         if (reply) {
 462                 if (!dbus_connection_send(connection, reply, NULL))
 463                         goto oom;
 464
 465                 dbus_message_unref(reply);
 466         }
 467
 468         return DBUS_HANDLER_RESULT_HANDLED;
 469
 470 oom:
 471         free(path);
 472
 473         if (reply)
 474                 dbus_message_unref(reply);
 475
 476         dbus_error_free(&error);
 477
 478         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 479 }
 480
 481 static DBusHandlerResult bus_unit_message_handler(DBusConnection *connection, DBusMessage  *message, void *data) {
 482         Manager *m = data;
 483         Unit *u;
 484         int r;
 485         DBusMessage *reply;
 486
 487         assert(connection);
 488         assert(message);
 489         assert(m);
 490
 491         if (streq(dbus_message_get_path(message), "/org/freedesktop/systemd1/unit")) {
 492                 /* Be nice to gdbus and return introspection data for our mid-level paths */
 493
 494                 if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect")) {
 495                         char *introspection = NULL;
 496                         FILE *f;
 497                         Iterator i;
 498                         const char *k;
 499                         size_t size;
 500
 501                         if (!(reply = dbus_message_new_method_return(message)))
 502                                 goto oom;
 503
 504                         /* We roll our own introspection code here, instead of
 505                          * relying on bus_default_message_handler() because we
 506                          * need to generate our introspection string
 507                          * dynamically. */
 508
 509                         if (!(f = open_memstream(&introspection, &size)))
 510                                 goto oom;
 511
 512                         fputs(DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
 513                               "<node>\n", f);
 514
 515                         fputs(BUS_INTROSPECTABLE_INTERFACE, f);
 516                         fputs(BUS_PEER_INTERFACE, f);
 517
 518                         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 519                                 char *p;
 520
 521                                 if (k != u->meta.id)
 522                                         continue;
 523
 524                                 if (!(p = bus_path_escape(k))) {
 525                                         fclose(f);
 526                                         free(introspection);
 527                                         goto oom;
 528                                 }
 529
 530                                 fprintf(f, "<node name=\"%s\"/>", p);
 531                                 free(p);
 532                         }
 533
 534                         fputs("</node>\n", f);
 535
 536                         if (ferror(f)) {
 537                                 fclose(f);
 538                                 free(introspection);
 539                                 goto oom;
 540                         }
 541
 542                         fclose(f);
 543
 544                         if (!introspection)
 545                                 goto oom;
 546
 547                         if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection, DBUS_TYPE_INVALID)) {
 548                                 free(introspection);
 549                                 goto oom;
 550                         }
 551
 552                         free(introspection);
 553
 554                         if (!dbus_connection_send(connection, reply, NULL))
 555                                 goto oom;
 556
 557                         dbus_message_unref(reply);
 558
 559                         return DBUS_HANDLER_RESULT_HANDLED;
 560                 }
 561
 562                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 563         }
 564
 565         if ((r = manager_get_unit_from_dbus_path(m, dbus_message_get_path(message), &u)) < 0) {
 566
 567                 if (r == -ENOMEM)
 568                         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 569
 570                 if (r == -ENOENT)
 571                         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 572
 573                 return bus_send_error_reply(m, connection, message, NULL, r);
 574         }
 575
 576         return bus_unit_message_dispatch(u, connection, message);
 577
 578 oom:
 579         if (reply)
 580                 dbus_message_unref(reply);
 581
 582         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 583 }
 584
 585 const DBusObjectPathVTable bus_unit_vtable = {
 586         .message_function = bus_unit_message_handler
 587 };
 588
 589 void bus_unit_send_change_signal(Unit *u) {
 590         char *p = NULL;
 591         DBusMessage *m = NULL;
 592
 593         assert(u);
 594
 595         if (u->meta.in_dbus_queue) {
 596                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 597                 u->meta.in_dbus_queue = false;
 598         }
 599
 600         if (!u->meta.id)
 601                 return;
 602
 603         if (!bus_has_subscriber(u->meta.manager)) {
 604                 u->meta.sent_dbus_new_signal = true;
 605                 return;
 606         }
 607
 608         if (!(p = unit_dbus_path(u)))
 609                 goto oom;
 610
 611         if (u->meta.sent_dbus_new_signal) {
 612                 /* Send a properties changed signal. First for the
 613                  * specific type, then for the generic unit. The
 614                  * clients may rely on this order to get atomic
 615                  * behaviour if needed. */
 616
 617                 if (UNIT_VTABLE(u)->bus_invalidating_properties) {
 618
 619                         if (!(m = bus_properties_changed_new(p,
 620                                                              UNIT_VTABLE(u)->bus_interface,
 621                                                              UNIT_VTABLE(u)->bus_invalidating_properties)))
 622                                 goto oom;
 623
 624                         if (bus_broadcast(u->meta.manager, m) < 0)
 625                                 goto oom;
 626
 627                         dbus_message_unref(m);
 628                 }
 629
 630                 if (!(m = bus_properties_changed_new(p, "org.freedesktop.systemd1.Unit", INVALIDATING_PROPERTIES)))
 631                         goto oom;
 632
 633         } else {
 634                 /* Send a new signal */
 635
 636                 if (!(m = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "UnitNew")))
 637                         goto oom;
 638
 639                 if (!dbus_message_append_args(m,
 640                                               DBUS_TYPE_STRING, &u->meta.id,
 641                                               DBUS_TYPE_OBJECT_PATH, &p,
 642                                               DBUS_TYPE_INVALID))
 643                         goto oom;
 644         }
 645
 646         if (bus_broadcast(u->meta.manager, m) < 0)
 647                 goto oom;
 648
 649         free(p);
 650         dbus_message_unref(m);
 651
 652         u->meta.sent_dbus_new_signal = true;
 653
 654         return;
 655
 656 oom:
 657         free(p);
 658
 659         if (m)
 660                 dbus_message_unref(m);
 661
 662         log_error("Failed to allocate unit change/new signal.");
 663 }
 664
 665 void bus_unit_send_removed_signal(Unit *u) {
 666         char *p = NULL;
 667         DBusMessage *m = NULL;
 668
 669         assert(u);
 670
 671         if (!bus_has_subscriber(u->meta.manager))
 672                 return;
 673
 674         if (!u->meta.sent_dbus_new_signal)
 675                 bus_unit_send_change_signal(u);
 676
 677         if (!u->meta.id)
 678                 return;
 679
 680         if (!(p = unit_dbus_path(u)))
 681                 goto oom;
 682
 683         if (!(m = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "UnitRemoved")))
 684                 goto oom;
 685
 686         if (!dbus_message_append_args(m,
 687                                       DBUS_TYPE_STRING, &u->meta.id,
 688                                       DBUS_TYPE_OBJECT_PATH, &p,
 689                                       DBUS_TYPE_INVALID))
 690                 goto oom;
 691
 692         if (bus_broadcast(u->meta.manager, m) < 0)
 693                 goto oom;
 694
 695         free(p);
 696         dbus_message_unref(m);
 697
 698         return;
 699
 700 oom:
 701         free(p);
 702
 703         if (m)
 704                 dbus_message_unref(m);
 705
 706         log_error("Failed to allocate unit remove signal.");
 707 }