src/dbus-common.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 <assert.h>
  23 #include <sys/socket.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <dbus/dbus.h>
  29 #include <string.h>
  30 #include <sys/epoll.h>
  31
  32 #include "log.h"
  33 #include "dbus-common.h"
  34 #include "util.h"
  35 #include "def.h"
  36 #include "strv.h"
  37
  38 int bus_check_peercred(DBusConnection *c) {
  39         int fd;
  40         struct ucred ucred;
  41         socklen_t l;
  42
  43         assert(c);
  44
  45         assert_se(dbus_connection_get_unix_fd(c, &fd));
  46
  47         l = sizeof(struct ucred);
  48         if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l) < 0) {
  49                 log_error("SO_PEERCRED failed: %m");
  50                 return -errno;
  51         }
  52
  53         if (l != sizeof(struct ucred)) {
  54                 log_error("SO_PEERCRED returned wrong size.");
  55                 return -E2BIG;
  56         }
  57
  58         if (ucred.uid != 0 && ucred.uid != geteuid())
  59                 return -EPERM;
  60
  61         return 1;
  62 }
  63
  64 static int sync_auth(DBusConnection *bus, DBusError *error) {
  65         usec_t begin, tstamp;
  66
  67         assert(bus);
  68
  69         /* This complexity should probably move into D-Bus itself:
  70          *
  71          * https://bugs.freedesktop.org/show_bug.cgi?id=35189 */
  72
  73         begin = tstamp = now(CLOCK_MONOTONIC);
  74         for (;;) {
  75
  76                 if (tstamp > begin + DEFAULT_TIMEOUT_USEC)
  77                         break;
  78
  79                 if (dbus_connection_get_is_authenticated(bus))
  80                         break;
  81
  82                 if (!dbus_connection_read_write_dispatch(bus, ((begin + DEFAULT_TIMEOUT_USEC - tstamp) + USEC_PER_MSEC - 1) / USEC_PER_MSEC))
  83                         break;
  84
  85                 tstamp = now(CLOCK_MONOTONIC);
  86         }
  87
  88         if (!dbus_connection_get_is_connected(bus)) {
  89                 dbus_set_error_const(error, DBUS_ERROR_NO_SERVER, "Connection terminated during authentication.");
  90                 return -ECONNREFUSED;
  91         }
  92
  93         if (!dbus_connection_get_is_authenticated(bus)) {
  94                 dbus_set_error_const(error, DBUS_ERROR_TIMEOUT, "Failed to authenticate in time.");
  95                 return -EACCES;
  96         }
  97
  98         return 0;
  99 }
 100
 101 int bus_connect(DBusBusType t, DBusConnection **_bus, bool *_private, DBusError *error) {
 102         DBusConnection *bus = NULL;
 103         int r;
 104         bool private = true;
 105
 106         assert(_bus);
 107
 108         if (geteuid() == 0 && t == DBUS_BUS_SYSTEM) {
 109                 /* If we are root, then let's talk directly to the
 110                  * system instance, instead of going via the bus */
 111
 112                 bus = dbus_connection_open_private("unix:path=/run/systemd/private", error);
 113                 if (!bus)
 114                         return -EIO;
 115
 116         } else {
 117                 if (t == DBUS_BUS_SESSION) {
 118                         const char *e;
 119
 120                         /* If we are supposed to talk to the instance,
 121                          * try via XDG_RUNTIME_DIR first, then
 122                          * fallback to normal bus access */
 123
 124                         e = getenv("XDG_RUNTIME_DIR");
 125                         if (e) {
 126                                 char *p;
 127
 128                                 if (asprintf(&p, "unix:path=%s/systemd/private", e) < 0)
 129                                         return -ENOMEM;
 130
 131                                 bus = dbus_connection_open_private(p, NULL);
 132                                 free(p);
 133                         }
 134                 }
 135
 136                 if (!bus) {
 137                         bus = dbus_bus_get_private(t, error);
 138                         if (!bus)
 139                                 return -EIO;
 140
 141                         private = false;
 142                 }
 143         }
 144
 145         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 146
 147         if (private) {
 148                 if (bus_check_peercred(bus) < 0) {
 149                         dbus_connection_close(bus);
 150                         dbus_connection_unref(bus);
 151
 152                         dbus_set_error_const(error, DBUS_ERROR_ACCESS_DENIED, "Failed to verify owner of bus.");
 153                         return -EACCES;
 154                 }
 155         }
 156
 157         r = sync_auth(bus, error);
 158         if (r < 0) {
 159                 dbus_connection_close(bus);
 160                 dbus_connection_unref(bus);
 161                 return r;
 162         }
 163
 164         if (_private)
 165                 *_private = private;
 166
 167         *_bus = bus;
 168         return 0;
 169 }
 170
 171 int bus_connect_system_ssh(const char *user, const char *host, DBusConnection **_bus, DBusError *error) {
 172         DBusConnection *bus;
 173         char *p = NULL;
 174         int r;
 175
 176         assert(_bus);
 177         assert(user || host);
 178
 179         if (user && host)
 180                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s@%s,argv3=systemd-stdio-bridge", user, host);
 181         else if (user)
 182                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s@localhost,argv3=systemd-stdio-bridge", user);
 183         else if (host)
 184                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s,argv3=systemd-stdio-bridge", host);
 185
 186         if (!p) {
 187                 dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
 188                 return -ENOMEM;
 189         }
 190
 191         bus = dbus_connection_open_private(p, error);
 192         free(p);
 193
 194         if (!bus)
 195                 return -EIO;
 196
 197         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 198
 199         if ((r = sync_auth(bus, error)) < 0) {
 200                 dbus_connection_close(bus);
 201                 dbus_connection_unref(bus);
 202                 return r;
 203         }
 204
 205         if (!dbus_bus_register(bus, error)) {
 206                 dbus_connection_close(bus);
 207                 dbus_connection_unref(bus);
 208                 return r;
 209         }
 210
 211         *_bus = bus;
 212         return 0;
 213 }
 214
 215 int bus_connect_system_polkit(DBusConnection **_bus, DBusError *error) {
 216         DBusConnection *bus;
 217         int r;
 218
 219         assert(_bus);
 220
 221         /* Don't bother with PolicyKit if we are root */
 222         if (geteuid() == 0)
 223                 return bus_connect(DBUS_BUS_SYSTEM, _bus, NULL, error);
 224
 225         if (!(bus = dbus_connection_open_private("exec:path=pkexec,argv1=" SYSTEMD_STDIO_BRIDGE_BINARY_PATH, error)))
 226                 return -EIO;
 227
 228         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 229
 230         if ((r = sync_auth(bus, error)) < 0) {
 231                 dbus_connection_close(bus);
 232                 dbus_connection_unref(bus);
 233                 return r;
 234         }
 235
 236         if (!dbus_bus_register(bus, error)) {
 237                 dbus_connection_close(bus);
 238                 dbus_connection_unref(bus);
 239                 return r;
 240         }
 241
 242         *_bus = bus;
 243         return 0;
 244 }
 245
 246 const char *bus_error_message(const DBusError *error) {
 247         assert(error);
 248
 249         /* Sometimes the D-Bus server is a little bit too verbose with
 250          * its error messages, so let's override them here */
 251         if (dbus_error_has_name(error, DBUS_ERROR_ACCESS_DENIED))
 252                 return "Access denied";
 253
 254         return error->message;
 255 }
 256
 257 DBusHandlerResult bus_default_message_handler(
 258                 DBusConnection *c,
 259                 DBusMessage *message,
 260                 const char *introspection,
 261                 const char *interfaces,
 262                 const BusProperty *properties) {
 263
 264         DBusError error;
 265         DBusMessage *reply = NULL;
 266         int r;
 267
 268         assert(c);
 269         assert(message);
 270
 271         dbus_error_init(&error);
 272
 273         if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect") && introspection) {
 274
 275                 if (!(reply = dbus_message_new_method_return(message)))
 276                         goto oom;
 277
 278                 if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection, DBUS_TYPE_INVALID))
 279                         goto oom;
 280
 281         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Get") && properties) {
 282                 const char *interface, *property;
 283                 const BusProperty *p;
 284
 285                 if (!dbus_message_get_args(
 286                             message,
 287                             &error,
 288                             DBUS_TYPE_STRING, &interface,
 289                             DBUS_TYPE_STRING, &property,
 290                             DBUS_TYPE_INVALID))
 291                         return bus_send_error_reply(c, message, &error, -EINVAL);
 292
 293                 for (p = properties; p->property; p++)
 294                         if (streq(p->interface, interface) && streq(p->property, property))
 295                                 break;
 296
 297                 if (p->property) {
 298                         DBusMessageIter iter, sub;
 299
 300                         if (!(reply = dbus_message_new_method_return(message)))
 301                                 goto oom;
 302
 303                         dbus_message_iter_init_append(reply, &iter);
 304
 305                         if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, p->signature, &sub))
 306                                 goto oom;
 307
 308                         if ((r = p->append(&sub, property, (void*) p->data)) < 0) {
 309
 310                                 if (r == -ENOMEM)
 311                                         goto oom;
 312
 313                                 dbus_message_unref(reply);
 314                                 return bus_send_error_reply(c, message, NULL, r);
 315                         }
 316
 317                         if (!dbus_message_iter_close_container(&iter, &sub))
 318                                 goto oom;
 319                 } else {
 320                         if (!nulstr_contains(interfaces, interface))
 321                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 322                         else
 323                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_PROPERTY, "Unknown property");
 324
 325                         return bus_send_error_reply(c, message, &error, -EINVAL);
 326                 }
 327
 328         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "GetAll") && properties) {
 329                 const char *interface;
 330                 const BusProperty *p;
 331                 DBusMessageIter iter, sub, sub2, sub3;
 332
 333                 if (!dbus_message_get_args(
 334                             message,
 335                             &error,
 336                             DBUS_TYPE_STRING, &interface,
 337                             DBUS_TYPE_INVALID))
 338                         return bus_send_error_reply(c, message, &error, -EINVAL);
 339
 340                 if (interface[0] && !nulstr_contains(interfaces, interface)) {
 341                         dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 342                         return bus_send_error_reply(c, message, &error, -EINVAL);
 343                 }
 344
 345                 if (!(reply = dbus_message_new_method_return(message)))
 346                         goto oom;
 347
 348                 dbus_message_iter_init_append(reply, &iter);
 349
 350                 if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub))
 351                         goto oom;
 352
 353                 for (p = properties; p->property; p++) {
 354                         if (interface[0] && !streq(p->interface, interface))
 355                                 continue;
 356
 357                         if (!dbus_message_iter_open_container(&sub, DBUS_TYPE_DICT_ENTRY, NULL, &sub2) ||
 358                             !dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, &p->property) ||
 359                             !dbus_message_iter_open_container(&sub2, DBUS_TYPE_VARIANT, p->signature, &sub3))
 360                                 goto oom;
 361
 362                         if ((r = p->append(&sub3, p->property, (void*) p->data)) < 0) {
 363
 364                                 if (r == -ENOMEM)
 365                                         goto oom;
 366
 367                                 dbus_message_unref(reply);
 368                                 return bus_send_error_reply(c, message, NULL, r);
 369                         }
 370
 371                         if (!dbus_message_iter_close_container(&sub2, &sub3) ||
 372                             !dbus_message_iter_close_container(&sub, &sub2))
 373                                 goto oom;
 374                 }
 375
 376                 if (!dbus_message_iter_close_container(&iter, &sub))
 377                         goto oom;
 378
 379         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Set") && properties) {
 380                 const char *interface, *property;
 381                 DBusMessageIter iter;
 382                 const BusProperty *p;
 383
 384                 if (!dbus_message_iter_init(message, &iter) ||
 385                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING)
 386                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 387
 388                 dbus_message_iter_get_basic(&iter, &interface);
 389
 390                 if (!dbus_message_iter_next(&iter) ||
 391                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING)
 392                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 393
 394                 dbus_message_iter_get_basic(&iter, &property);
 395
 396                 if (!dbus_message_iter_next(&iter) ||
 397                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT ||
 398                     dbus_message_iter_has_next(&iter))
 399                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 400
 401                 for (p = properties; p->property; p++)
 402                         if (streq(p->interface, interface) && streq(p->property, property))
 403                                 break;
 404
 405                 if (p->set) {
 406                         DBusMessageIter sub;
 407                         char *sig;
 408
 409                         dbus_message_iter_recurse(&iter, &sub);
 410
 411                         if (!(sig = dbus_message_iter_get_signature(&sub)))
 412                                 goto oom;
 413
 414                         if (!streq(sig, p->signature)) {
 415                                 dbus_free(sig);
 416                                 return bus_send_error_reply(c, message, NULL, -EINVAL);
 417                         }
 418
 419                         dbus_free(sig);
 420
 421                         if ((r = p->set(&sub, property)) < 0) {
 422                                 if (r == -ENOMEM)
 423                                         goto oom;
 424                                 return bus_send_error_reply(c, message, NULL, r);
 425                         }
 426
 427                         if (!(reply = dbus_message_new_method_return(message)))
 428                                 goto oom;
 429                 } else {
 430                         if (p->property)
 431                                 dbus_set_error_const(&error, DBUS_ERROR_PROPERTY_READ_ONLY, "Property read-only");
 432                         else if (!nulstr_contains(interfaces, interface))
 433                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 434                         else
 435                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_PROPERTY, "Unknown property");
 436
 437                         return bus_send_error_reply(c, message, &error, -EINVAL);
 438                 }
 439
 440         } else {
 441                 const char *interface = dbus_message_get_interface(message);
 442
 443                 if (!interface || !nulstr_contains(interfaces, interface)) {
 444                         dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 445                         return bus_send_error_reply(c, message, &error, -EINVAL);
 446                 }
 447         }
 448
 449         if (reply) {
 450                 if (!dbus_connection_send(c, reply, NULL))
 451                         goto oom;
 452
 453                 dbus_message_unref(reply);
 454                 return DBUS_HANDLER_RESULT_HANDLED;
 455         }
 456
 457         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 458
 459 oom:
 460         if (reply)
 461                 dbus_message_unref(reply);
 462
 463         dbus_error_free(&error);
 464
 465         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 466 }
 467
 468 int bus_property_append_string(DBusMessageIter *i, const char *property, void *data) {
 469         const char *t = data;
 470
 471         assert(i);
 472         assert(property);
 473
 474         if (!t)
 475                 t = "";
 476
 477         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &t))
 478                 return -ENOMEM;
 479
 480         return 0;
 481 }
 482
 483 int bus_property_append_strv(DBusMessageIter *i, const char *property, void *data) {
 484         char **t = data;
 485
 486         assert(i);
 487         assert(property);
 488
 489         return bus_append_strv_iter(i, t);
 490 }
 491
 492 int bus_property_append_bool(DBusMessageIter *i, const char *property, void *data) {
 493         bool *b = data;
 494         dbus_bool_t db;
 495
 496         assert(i);
 497         assert(property);
 498         assert(b);
 499
 500         db = *b;
 501
 502         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &db))
 503                 return -ENOMEM;
 504
 505         return 0;
 506 }
 507
 508 int bus_property_append_uint64(DBusMessageIter *i, const char *property, void *data) {
 509         assert(i);
 510         assert(property);
 511         assert(data);
 512
 513         /* Let's ensure that usec_t is actually 64bit, and hence this
 514          * function can be used for usec_t */
 515         assert_cc(sizeof(uint64_t) == sizeof(usec_t));
 516
 517         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, data))
 518                 return -ENOMEM;
 519
 520         return 0;
 521 }
 522
 523 int bus_property_append_uint32(DBusMessageIter *i, const char *property, void *data) {
 524         assert(i);
 525         assert(property);
 526         assert(data);
 527
 528         /* Let's ensure that pid_t, mode_t, uid_t, gid_t are actually
 529          * 32bit, and hence this function can be used for
 530          * pid_t/mode_t/uid_t/gid_t */
 531         assert_cc(sizeof(uint32_t) == sizeof(pid_t));
 532         assert_cc(sizeof(uint32_t) == sizeof(mode_t));
 533         assert_cc(sizeof(uint32_t) == sizeof(unsigned));
 534         assert_cc(sizeof(uint32_t) == sizeof(uid_t));
 535         assert_cc(sizeof(uint32_t) == sizeof(gid_t));
 536
 537         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT32, data))
 538                 return -ENOMEM;
 539
 540         return 0;
 541 }
 542
 543 int bus_property_append_int32(DBusMessageIter *i, const char *property, void *data) {
 544         assert(i);
 545         assert(property);
 546         assert(data);
 547
 548         assert_cc(sizeof(int32_t) == sizeof(int));
 549
 550         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_INT32, data))
 551                 return -ENOMEM;
 552
 553         return 0;
 554 }
 555
 556 int bus_property_append_size(DBusMessageIter *i, const char *property, void *data) {
 557         uint64_t u;
 558
 559         assert(i);
 560         assert(property);
 561         assert(data);
 562
 563         u = (uint64_t) *(size_t*) data;
 564
 565         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, &u))
 566                 return -ENOMEM;
 567
 568         return 0;
 569 }
 570
 571 int bus_property_append_ul(DBusMessageIter *i, const char *property, void *data) {
 572         uint64_t u;
 573
 574         assert(i);
 575         assert(property);
 576         assert(data);
 577
 578         u = (uint64_t) *(unsigned long*) data;
 579
 580         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, &u))
 581                 return -ENOMEM;
 582
 583         return 0;
 584 }
 585
 586 int bus_property_append_long(DBusMessageIter *i, const char *property, void *data) {
 587         int64_t l;
 588
 589         assert(i);
 590         assert(property);
 591         assert(data);
 592
 593         l = (int64_t) *(long*) data;
 594
 595         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_INT64, &l))
 596                 return -ENOMEM;
 597
 598         return 0;
 599 }
 600
 601 const char *bus_errno_to_dbus(int error) {
 602
 603         switch(error) {
 604
 605         case -EINVAL:
 606                 return DBUS_ERROR_INVALID_ARGS;
 607
 608         case -ENOMEM:
 609                 return DBUS_ERROR_NO_MEMORY;
 610
 611         case -EPERM:
 612         case -EACCES:
 613                 return DBUS_ERROR_ACCESS_DENIED;
 614
 615         case -ESRCH:
 616                 return DBUS_ERROR_UNIX_PROCESS_ID_UNKNOWN;
 617
 618         case -ENOENT:
 619                 return DBUS_ERROR_FILE_NOT_FOUND;
 620
 621         case -EEXIST:
 622                 return DBUS_ERROR_FILE_EXISTS;
 623
 624         case -ETIMEDOUT:
 625         case -ETIME:
 626                 return DBUS_ERROR_TIMEOUT;
 627
 628         case -EIO:
 629                 return DBUS_ERROR_IO_ERROR;
 630
 631         case -ENETRESET:
 632         case -ECONNABORTED:
 633         case -ECONNRESET:
 634                 return DBUS_ERROR_DISCONNECTED;
 635         }
 636
 637         return DBUS_ERROR_FAILED;
 638 }
 639
 640 DBusHandlerResult bus_send_error_reply(DBusConnection *c, DBusMessage *message, DBusError *berror, int error) {
 641         DBusMessage *reply = NULL;
 642         const char *name, *text;
 643
 644         if (berror && dbus_error_is_set(berror)) {
 645                 name = berror->name;
 646                 text = berror->message;
 647         } else {
 648                 name = bus_errno_to_dbus(error);
 649                 text = strerror(-error);
 650         }
 651
 652         if (!(reply = dbus_message_new_error(message, name, text)))
 653                 goto oom;
 654
 655         if (!dbus_connection_send(c, reply, NULL))
 656                 goto oom;
 657
 658         dbus_message_unref(reply);
 659
 660         if (berror)
 661                 dbus_error_free(berror);
 662
 663         return DBUS_HANDLER_RESULT_HANDLED;
 664
 665 oom:
 666         if (reply)
 667                 dbus_message_unref(reply);
 668
 669         if (berror)
 670                 dbus_error_free(berror);
 671
 672         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 673 }
 674
 675 DBusMessage* bus_properties_changed_new(const char *path, const char *interface, const char *properties) {
 676         DBusMessage *m;
 677         DBusMessageIter iter, sub;
 678         const char *i;
 679
 680         assert(interface);
 681         assert(properties);
 682
 683         if (!(m = dbus_message_new_signal(path, "org.freedesktop.DBus.Properties", "PropertiesChanged")))
 684                 goto oom;
 685
 686         dbus_message_iter_init_append(m, &iter);
 687
 688         /* We won't send any property values, since they might be
 689          * large and sometimes not cheap to generated */
 690
 691         if (!dbus_message_iter_append_basic(&iter, DBUS_TYPE_STRING, &interface) ||
 692             !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub) ||
 693             !dbus_message_iter_close_container(&iter, &sub) ||
 694             !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "s", &sub))
 695                 goto oom;
 696
 697         NULSTR_FOREACH(i, properties)
 698                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &i))
 699                         goto oom;
 700
 701         if (!dbus_message_iter_close_container(&iter, &sub))
 702                 goto oom;
 703
 704         return m;
 705
 706 oom:
 707         if (m)
 708                 dbus_message_unref(m);
 709
 710         return NULL;
 711 }
 712
 713 uint32_t bus_flags_to_events(DBusWatch *bus_watch) {
 714         unsigned flags;
 715         uint32_t events = 0;
 716
 717         assert(bus_watch);
 718
 719         /* no watch flags for disabled watches */
 720         if (!dbus_watch_get_enabled(bus_watch))
 721                 return 0;
 722
 723         flags = dbus_watch_get_flags(bus_watch);
 724
 725         if (flags & DBUS_WATCH_READABLE)
 726                 events |= EPOLLIN;
 727         if (flags & DBUS_WATCH_WRITABLE)
 728                 events |= EPOLLOUT;
 729
 730         return events | EPOLLHUP | EPOLLERR;
 731 }
 732
 733 unsigned bus_events_to_flags(uint32_t events) {
 734         unsigned flags = 0;
 735
 736         if (events & EPOLLIN)
 737                 flags |= DBUS_WATCH_READABLE;
 738         if (events & EPOLLOUT)
 739                 flags |= DBUS_WATCH_WRITABLE;
 740         if (events & EPOLLHUP)
 741                 flags |= DBUS_WATCH_HANGUP;
 742         if (events & EPOLLERR)
 743                 flags |= DBUS_WATCH_ERROR;
 744
 745         return flags;
 746 }
 747
 748 int bus_parse_strv(DBusMessage *m, char ***_l) {
 749         DBusMessageIter iter;
 750
 751         assert(m);
 752         assert(_l);
 753
 754         if (!dbus_message_iter_init(m, &iter))
 755                 return -EINVAL;
 756
 757         return bus_parse_strv_iter(&iter, _l);
 758 }
 759
 760 int bus_parse_strv_iter(DBusMessageIter *iter, char ***_l) {
 761         DBusMessageIter sub;
 762         unsigned n = 0, i = 0;
 763         char **l;
 764
 765         assert(iter);
 766         assert(_l);
 767
 768         if (dbus_message_iter_get_arg_type(iter) != DBUS_TYPE_ARRAY ||
 769             dbus_message_iter_get_element_type(iter) != DBUS_TYPE_STRING)
 770             return -EINVAL;
 771
 772         dbus_message_iter_recurse(iter, &sub);
 773
 774         while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 775                 n++;
 776                 dbus_message_iter_next(&sub);
 777         }
 778
 779         if (!(l = new(char*, n+1)))
 780                 return -ENOMEM;
 781
 782         dbus_message_iter_recurse(iter, &sub);
 783
 784         while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 785                 const char *s;
 786
 787                 assert_se(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
 788                 dbus_message_iter_get_basic(&sub, &s);
 789
 790                 if (!(l[i++] = strdup(s))) {
 791                         strv_free(l);
 792                         return -ENOMEM;
 793                 }
 794
 795                 dbus_message_iter_next(&sub);
 796         }
 797
 798         assert(i == n);
 799         l[i] = NULL;
 800
 801         if (_l)
 802                 *_l = l;
 803
 804         return 0;
 805 }
 806
 807 int bus_append_strv_iter(DBusMessageIter *iter, char **l) {
 808         DBusMessageIter sub;
 809
 810         assert(iter);
 811
 812         if (!dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY, "s", &sub))
 813                 return -ENOMEM;
 814
 815         STRV_FOREACH(l, l)
 816                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, l))
 817                         return -ENOMEM;
 818
 819         if (!dbus_message_iter_close_container(iter, &sub))
 820                 return -ENOMEM;
 821
 822         return 0;
 823 }
 824
 825 int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *data, bool next) {
 826
 827         assert(iter);
 828         assert(data);
 829
 830         if (dbus_message_iter_get_arg_type(iter) != type)
 831                 return -EIO;
 832
 833         dbus_message_iter_get_basic(iter, data);
 834
 835         if (!dbus_message_iter_next(iter) != !next)
 836                 return -EIO;
 837
 838         return 0;
 839 }
 840
 841 int generic_print_property(const char *name, DBusMessageIter *iter, bool all) {
 842         assert(name);
 843         assert(iter);
 844
 845         switch (dbus_message_iter_get_arg_type(iter)) {
 846
 847         case DBUS_TYPE_STRING: {
 848                 const char *s;
 849                 dbus_message_iter_get_basic(iter, &s);
 850
 851                 if (all || !isempty(s))
 852                         printf("%s=%s\n", name, s);
 853
 854                 return 1;
 855         }
 856
 857         case DBUS_TYPE_BOOLEAN: {
 858                 dbus_bool_t b;
 859
 860                 dbus_message_iter_get_basic(iter, &b);
 861                 printf("%s=%s\n", name, yes_no(b));
 862
 863                 return 1;
 864         }
 865
 866         case DBUS_TYPE_UINT64: {
 867                 uint64_t u;
 868                 dbus_message_iter_get_basic(iter, &u);
 869
 870                 /* Yes, heuristics! But we can change this check
 871                  * should it turn out to not be sufficient */
 872
 873                 if (endswith(name, "Timestamp")) {
 874                         char timestamp[FORMAT_TIMESTAMP_MAX], *t;
 875
 876                         t = format_timestamp(timestamp, sizeof(timestamp), u);
 877                         if (t || all)
 878                                 printf("%s=%s\n", name, strempty(t));
 879
 880                 } else if (strstr(name, "USec")) {
 881                         char timespan[FORMAT_TIMESPAN_MAX];
 882
 883                         printf("%s=%s\n", name, format_timespan(timespan, sizeof(timespan), u));
 884                 } else
 885                         printf("%s=%llu\n", name, (unsigned long long) u);
 886
 887                 return 1;
 888         }
 889
 890         case DBUS_TYPE_UINT32: {
 891                 uint32_t u;
 892                 dbus_message_iter_get_basic(iter, &u);
 893
 894                 if (strstr(name, "UMask") || strstr(name, "Mode"))
 895                         printf("%s=%04o\n", name, u);
 896                 else
 897                         printf("%s=%u\n", name, (unsigned) u);
 898
 899                 return 1;
 900         }
 901
 902         case DBUS_TYPE_INT32: {
 903                 int32_t i;
 904                 dbus_message_iter_get_basic(iter, &i);
 905
 906                 printf("%s=%i\n", name, (int) i);
 907                 return 1;
 908         }
 909
 910         case DBUS_TYPE_DOUBLE: {
 911                 double d;
 912                 dbus_message_iter_get_basic(iter, &d);
 913
 914                 printf("%s=%g\n", name, d);
 915                 return 1;
 916         }
 917
 918         case DBUS_TYPE_ARRAY:
 919
 920                 if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRING) {
 921                         DBusMessageIter sub;
 922                         bool space = false;
 923
 924                         dbus_message_iter_recurse(iter, &sub);
 925                         if (all ||
 926                             dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 927                                 printf("%s=", name);
 928
 929                                 while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 930                                         const char *s;
 931
 932                                         assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
 933                                         dbus_message_iter_get_basic(&sub, &s);
 934                                         printf("%s%s", space ? " " : "", s);
 935
 936                                         space = true;
 937                                         dbus_message_iter_next(&sub);
 938                                 }
 939
 940                                 puts("");
 941                         }
 942
 943                         return 1;
 944
 945                 } else if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_BYTE) {
 946                         DBusMessageIter sub;
 947
 948                         dbus_message_iter_recurse(iter, &sub);
 949                         if (all ||
 950                             dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 951                                 printf("%s=", name);
 952
 953                                 while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
 954                                         uint8_t u;
 955
 956                                         assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_BYTE);
 957                                         dbus_message_iter_get_basic(&sub, &u);
 958                                         printf("%02x", u);
 959
 960                                         dbus_message_iter_next(&sub);
 961                                 }
 962
 963                                 puts("");
 964                         }
 965
 966                         return 1;
 967                 }
 968
 969                 break;
 970         }
 971
 972         return 0;
 973 }