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)
  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;
 103         int r;
 104
 105         assert(_bus);
 106
 107         /* If we are root, then let's not go via the bus */
 108         if (geteuid() == 0 && t == DBUS_BUS_SYSTEM) {
 109
 110                 if (!(bus = dbus_connection_open_private("unix:path=/run/systemd/private", error))) {
 111 #ifndef LEGACY
 112                         dbus_error_free(error);
 113
 114                         /* Retry with the pre v21 socket name, to ease upgrades */
 115                         if (!(bus = dbus_connection_open_private("unix:abstract=/org/freedesktop/systemd1/private", error)))
 116 #endif
 117                                 return -EIO;
 118                 }
 119
 120                 dbus_connection_set_exit_on_disconnect(bus, FALSE);
 121
 122                 if (bus_check_peercred(bus) < 0) {
 123                         dbus_connection_close(bus);
 124                         dbus_connection_unref(bus);
 125
 126                         dbus_set_error_const(error, DBUS_ERROR_ACCESS_DENIED, "Failed to verify owner of bus.");
 127                         return -EACCES;
 128                 }
 129
 130                 if (private)
 131                         *private = true;
 132
 133         } else {
 134                 if (!(bus = dbus_bus_get_private(t, error)))
 135                         return -EIO;
 136
 137                 dbus_connection_set_exit_on_disconnect(bus, FALSE);
 138
 139                 if (private)
 140                         *private = false;
 141         }
 142
 143         if ((r = sync_auth(bus, error)) < 0) {
 144                 dbus_connection_close(bus);
 145                 dbus_connection_unref(bus);
 146                 return r;
 147         }
 148
 149         *_bus = bus;
 150         return 0;
 151 }
 152
 153 int bus_connect_system_ssh(const char *user, const char *host, DBusConnection **_bus, DBusError *error) {
 154         DBusConnection *bus;
 155         char *p = NULL;
 156         int r;
 157
 158         assert(_bus);
 159         assert(user || host);
 160
 161         if (user && host)
 162                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s@%s,argv3=systemd-stdio-bridge", user, host);
 163         else if (user)
 164                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s@localhost,argv3=systemd-stdio-bridge", user);
 165         else if (host)
 166                 asprintf(&p, "exec:path=ssh,argv1=-xT,argv2=%s,argv3=systemd-stdio-bridge", host);
 167
 168         if (!p) {
 169                 dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
 170                 return -ENOMEM;
 171         }
 172
 173         bus = dbus_connection_open_private(p, error);
 174         free(p);
 175
 176         if (!bus)
 177                 return -EIO;
 178
 179         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 180
 181         if ((r = sync_auth(bus, error)) < 0) {
 182                 dbus_connection_close(bus);
 183                 dbus_connection_unref(bus);
 184                 return r;
 185         }
 186
 187         if (!dbus_bus_register(bus, error)) {
 188                 dbus_connection_close(bus);
 189                 dbus_connection_unref(bus);
 190                 return r;
 191         }
 192
 193         *_bus = bus;
 194         return 0;
 195 }
 196
 197 int bus_connect_system_polkit(DBusConnection **_bus, DBusError *error) {
 198         DBusConnection *bus;
 199         int r;
 200
 201         assert(_bus);
 202
 203         /* Don't bother with PolicyKit if we are root */
 204         if (geteuid() == 0)
 205                 return bus_connect(DBUS_BUS_SYSTEM, _bus, NULL, error);
 206
 207         if (!(bus = dbus_connection_open_private("exec:path=pkexec,argv1=" SYSTEMD_STDIO_BRIDGE_BINARY_PATH, error)))
 208                 return -EIO;
 209
 210         dbus_connection_set_exit_on_disconnect(bus, FALSE);
 211
 212         if ((r = sync_auth(bus, error)) < 0) {
 213                 dbus_connection_close(bus);
 214                 dbus_connection_unref(bus);
 215                 return r;
 216         }
 217
 218         if (!dbus_bus_register(bus, error)) {
 219                 dbus_connection_close(bus);
 220                 dbus_connection_unref(bus);
 221                 return r;
 222         }
 223
 224         *_bus = bus;
 225         return 0;
 226 }
 227
 228 const char *bus_error_message(const DBusError *error) {
 229         assert(error);
 230
 231         /* Sometimes the D-Bus server is a little bit too verbose with
 232          * its error messages, so let's override them here */
 233         if (dbus_error_has_name(error, DBUS_ERROR_ACCESS_DENIED))
 234                 return "Access denied";
 235
 236         return error->message;
 237 }
 238
 239 DBusHandlerResult bus_default_message_handler(
 240                 DBusConnection *c,
 241                 DBusMessage *message,
 242                 const char *introspection,
 243                 const char *interfaces,
 244                 const BusProperty *properties) {
 245
 246         DBusError error;
 247         DBusMessage *reply = NULL;
 248         int r;
 249
 250         assert(c);
 251         assert(message);
 252
 253         dbus_error_init(&error);
 254
 255         if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect") && introspection) {
 256
 257                 if (!(reply = dbus_message_new_method_return(message)))
 258                         goto oom;
 259
 260                 if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection, DBUS_TYPE_INVALID))
 261                         goto oom;
 262
 263         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Get") && properties) {
 264                 const char *interface, *property;
 265                 const BusProperty *p;
 266
 267                 if (!dbus_message_get_args(
 268                             message,
 269                             &error,
 270                             DBUS_TYPE_STRING, &interface,
 271                             DBUS_TYPE_STRING, &property,
 272                             DBUS_TYPE_INVALID))
 273                         return bus_send_error_reply(c, message, &error, -EINVAL);
 274
 275                 for (p = properties; p->property; p++)
 276                         if (streq(p->interface, interface) && streq(p->property, property))
 277                                 break;
 278
 279                 if (p->property) {
 280                         DBusMessageIter iter, sub;
 281
 282                         if (!(reply = dbus_message_new_method_return(message)))
 283                                 goto oom;
 284
 285                         dbus_message_iter_init_append(reply, &iter);
 286
 287                         if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, p->signature, &sub))
 288                                 goto oom;
 289
 290                         if ((r = p->append(&sub, property, (void*) p->data)) < 0) {
 291
 292                                 if (r == -ENOMEM)
 293                                         goto oom;
 294
 295                                 dbus_message_unref(reply);
 296                                 return bus_send_error_reply(c, message, NULL, r);
 297                         }
 298
 299                         if (!dbus_message_iter_close_container(&iter, &sub))
 300                                 goto oom;
 301                 } else {
 302                         if (!nulstr_contains(interfaces, interface))
 303                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 304                         else
 305                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_PROPERTY, "Unknown property");
 306
 307                         return bus_send_error_reply(c, message, &error, -EINVAL);
 308                 }
 309
 310         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "GetAll") && properties) {
 311                 const char *interface;
 312                 const BusProperty *p;
 313                 DBusMessageIter iter, sub, sub2, sub3;
 314
 315                 if (!dbus_message_get_args(
 316                             message,
 317                             &error,
 318                             DBUS_TYPE_STRING, &interface,
 319                             DBUS_TYPE_INVALID))
 320                         return bus_send_error_reply(c, message, &error, -EINVAL);
 321
 322                 if (interface[0] && !nulstr_contains(interfaces, interface)) {
 323                         dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 324                         return bus_send_error_reply(c, message, &error, -EINVAL);
 325                 }
 326
 327                 if (!(reply = dbus_message_new_method_return(message)))
 328                         goto oom;
 329
 330                 dbus_message_iter_init_append(reply, &iter);
 331
 332                 if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub))
 333                         goto oom;
 334
 335                 for (p = properties; p->property; p++) {
 336                         if (interface[0] && !streq(p->interface, interface))
 337                                 continue;
 338
 339                         if (!dbus_message_iter_open_container(&sub, DBUS_TYPE_DICT_ENTRY, NULL, &sub2) ||
 340                             !dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, &p->property) ||
 341                             !dbus_message_iter_open_container(&sub2, DBUS_TYPE_VARIANT, p->signature, &sub3))
 342                                 goto oom;
 343
 344                         if ((r = p->append(&sub3, p->property, (void*) p->data)) < 0) {
 345
 346                                 if (r == -ENOMEM)
 347                                         goto oom;
 348
 349                                 dbus_message_unref(reply);
 350                                 return bus_send_error_reply(c, message, NULL, r);
 351                         }
 352
 353                         if (!dbus_message_iter_close_container(&sub2, &sub3) ||
 354                             !dbus_message_iter_close_container(&sub, &sub2))
 355                                 goto oom;
 356                 }
 357
 358                 if (!dbus_message_iter_close_container(&iter, &sub))
 359                         goto oom;
 360
 361         } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Set") && properties) {
 362                 const char *interface, *property;
 363                 DBusMessageIter iter;
 364                 const BusProperty *p;
 365
 366                 if (!dbus_message_iter_init(message, &iter) ||
 367                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING)
 368                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 369
 370                 dbus_message_iter_get_basic(&iter, &interface);
 371
 372                 if (!dbus_message_iter_next(&iter) ||
 373                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING)
 374                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 375
 376                 dbus_message_iter_get_basic(&iter, &property);
 377
 378                 if (!dbus_message_iter_next(&iter) ||
 379                     dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT ||
 380                     dbus_message_iter_has_next(&iter))
 381                         return bus_send_error_reply(c, message, NULL, -EINVAL);
 382
 383                 for (p = properties; p->property; p++)
 384                         if (streq(p->interface, interface) && streq(p->property, property))
 385                                 break;
 386
 387                 if (p->set) {
 388                         DBusMessageIter sub;
 389                         char *sig;
 390
 391                         dbus_message_iter_recurse(&iter, &sub);
 392
 393                         if (!(sig = dbus_message_iter_get_signature(&sub)))
 394                                 goto oom;
 395
 396                         if (!streq(sig, p->signature)) {
 397                                 dbus_free(sig);
 398                                 return bus_send_error_reply(c, message, NULL, -EINVAL);
 399                         }
 400
 401                         dbus_free(sig);
 402
 403                         if ((r = p->set(&sub, property)) < 0) {
 404                                 if (r == -ENOMEM)
 405                                         goto oom;
 406                                 return bus_send_error_reply(c, message, NULL, r);
 407                         }
 408
 409                         if (!(reply = dbus_message_new_method_return(message)))
 410                                 goto oom;
 411                 } else {
 412                         if (p->property)
 413                                 dbus_set_error_const(&error, DBUS_ERROR_PROPERTY_READ_ONLY, "Property read-only");
 414                         else if (!nulstr_contains(interfaces, interface))
 415                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 416                         else
 417                                 dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_PROPERTY, "Unknown property");
 418
 419                         return bus_send_error_reply(c, message, &error, -EINVAL);
 420                 }
 421
 422         } else {
 423                 const char *interface = dbus_message_get_interface(message);
 424
 425                 if (!interface || !nulstr_contains(interfaces, interface)) {
 426                         dbus_set_error_const(&error, DBUS_ERROR_UNKNOWN_INTERFACE, "Unknown interface");
 427                         return bus_send_error_reply(c, message, &error, -EINVAL);
 428                 }
 429         }
 430
 431         if (reply) {
 432                 if (!dbus_connection_send(c, reply, NULL))
 433                         goto oom;
 434
 435                 dbus_message_unref(reply);
 436                 return DBUS_HANDLER_RESULT_HANDLED;
 437         }
 438
 439         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 440
 441 oom:
 442         if (reply)
 443                 dbus_message_unref(reply);
 444
 445         dbus_error_free(&error);
 446
 447         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 448 }
 449
 450 int bus_property_append_string(DBusMessageIter *i, const char *property, void *data) {
 451         const char *t = data;
 452
 453         assert(i);
 454         assert(property);
 455
 456         if (!t)
 457                 t = "";
 458
 459         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &t))
 460                 return -ENOMEM;
 461
 462         return 0;
 463 }
 464
 465 int bus_property_append_strv(DBusMessageIter *i, const char *property, void *data) {
 466         DBusMessageIter sub;
 467         char **t = data;
 468
 469         assert(i);
 470         assert(property);
 471
 472         if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub))
 473                 return -ENOMEM;
 474
 475         STRV_FOREACH(t, t)
 476                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, t))
 477                         return -ENOMEM;
 478
 479         if (!dbus_message_iter_close_container(i, &sub))
 480                 return -ENOMEM;
 481
 482         return 0;
 483 }
 484
 485 int bus_property_append_bool(DBusMessageIter *i, const char *property, void *data) {
 486         bool *b = data;
 487         dbus_bool_t db;
 488
 489         assert(i);
 490         assert(property);
 491         assert(b);
 492
 493         db = *b;
 494
 495         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &db))
 496                 return -ENOMEM;
 497
 498         return 0;
 499 }
 500
 501 int bus_property_append_uint64(DBusMessageIter *i, const char *property, void *data) {
 502         assert(i);
 503         assert(property);
 504         assert(data);
 505
 506         /* Let's ensure that pid_t is actually 64bit, and hence this
 507          * function can be used for usec_t */
 508         assert_cc(sizeof(uint64_t) == sizeof(usec_t));
 509
 510         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, data))
 511                 return -ENOMEM;
 512
 513         return 0;
 514 }
 515
 516 int bus_property_append_uint32(DBusMessageIter *i, const char *property, void *data) {
 517         assert(i);
 518         assert(property);
 519         assert(data);
 520
 521         /* Let's ensure that pid_t and mode_t is actually 32bit, and
 522          * hence this function can be used for pid_t/mode_t */
 523         assert_cc(sizeof(uint32_t) == sizeof(pid_t));
 524         assert_cc(sizeof(uint32_t) == sizeof(mode_t));
 525         assert_cc(sizeof(uint32_t) == sizeof(unsigned));
 526
 527         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT32, data))
 528                 return -ENOMEM;
 529
 530         return 0;
 531 }
 532
 533 int bus_property_append_int32(DBusMessageIter *i, const char *property, void *data) {
 534         assert(i);
 535         assert(property);
 536         assert(data);
 537
 538         assert_cc(sizeof(int32_t) == sizeof(int));
 539
 540         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_INT32, data))
 541                 return -ENOMEM;
 542
 543         return 0;
 544 }
 545
 546 int bus_property_append_size(DBusMessageIter *i, const char *property, void *data) {
 547         uint64_t u;
 548
 549         assert(i);
 550         assert(property);
 551         assert(data);
 552
 553         u = (uint64_t) *(size_t*) data;
 554
 555         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, &u))
 556                 return -ENOMEM;
 557
 558         return 0;
 559 }
 560
 561 int bus_property_append_ul(DBusMessageIter *i, const char *property, void *data) {
 562         uint64_t u;
 563
 564         assert(i);
 565         assert(property);
 566         assert(data);
 567
 568         u = (uint64_t) *(unsigned long*) data;
 569
 570         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, &u))
 571                 return -ENOMEM;
 572
 573         return 0;
 574 }
 575
 576 int bus_property_append_long(DBusMessageIter *i, const char *property, void *data) {
 577         int64_t l;
 578
 579         assert(i);
 580         assert(property);
 581         assert(data);
 582
 583         l = (int64_t) *(long*) data;
 584
 585         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_INT64, &l))
 586                 return -ENOMEM;
 587
 588         return 0;
 589 }
 590
 591 const char *bus_errno_to_dbus(int error) {
 592
 593         switch(error) {
 594
 595         case -EINVAL:
 596                 return DBUS_ERROR_INVALID_ARGS;
 597
 598         case -ENOMEM:
 599                 return DBUS_ERROR_NO_MEMORY;
 600
 601         case -EPERM:
 602         case -EACCES:
 603                 return DBUS_ERROR_ACCESS_DENIED;
 604
 605         case -ESRCH:
 606                 return DBUS_ERROR_UNIX_PROCESS_ID_UNKNOWN;
 607
 608         case -ENOENT:
 609                 return DBUS_ERROR_FILE_NOT_FOUND;
 610
 611         case -EEXIST:
 612                 return DBUS_ERROR_FILE_EXISTS;
 613
 614         case -ETIMEDOUT:
 615         case -ETIME:
 616                 return DBUS_ERROR_TIMEOUT;
 617
 618         case -EIO:
 619                 return DBUS_ERROR_IO_ERROR;
 620
 621         case -ENETRESET:
 622         case -ECONNABORTED:
 623         case -ECONNRESET:
 624                 return DBUS_ERROR_DISCONNECTED;
 625         }
 626
 627         return DBUS_ERROR_FAILED;
 628 }
 629
 630 DBusHandlerResult bus_send_error_reply(DBusConnection *c, DBusMessage *message, DBusError *berror, int error) {
 631         DBusMessage *reply = NULL;
 632         const char *name, *text;
 633
 634         if (berror && dbus_error_is_set(berror)) {
 635                 name = berror->name;
 636                 text = berror->message;
 637         } else {
 638                 name = bus_errno_to_dbus(error);
 639                 text = strerror(-error);
 640         }
 641
 642         if (!(reply = dbus_message_new_error(message, name, text)))
 643                 goto oom;
 644
 645         if (!dbus_connection_send(c, reply, NULL))
 646                 goto oom;
 647
 648         dbus_message_unref(reply);
 649
 650         if (berror)
 651                 dbus_error_free(berror);
 652
 653         return DBUS_HANDLER_RESULT_HANDLED;
 654
 655 oom:
 656         if (reply)
 657                 dbus_message_unref(reply);
 658
 659         if (berror)
 660                 dbus_error_free(berror);
 661
 662         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 663 }
 664
 665 DBusMessage* bus_properties_changed_new(const char *path, const char *interface, const char *properties) {
 666         DBusMessage *m;
 667         DBusMessageIter iter, sub;
 668         const char *i;
 669
 670         assert(interface);
 671         assert(properties);
 672
 673         if (!(m = dbus_message_new_signal(path, "org.freedesktop.DBus.Properties", "PropertiesChanged")))
 674                 goto oom;
 675
 676         dbus_message_iter_init_append(m, &iter);
 677
 678         /* We won't send any property values, since they might be
 679          * large and sometimes not cheap to generated */
 680
 681         if (!dbus_message_iter_append_basic(&iter, DBUS_TYPE_STRING, &interface) ||
 682             !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub) ||
 683             !dbus_message_iter_close_container(&iter, &sub) ||
 684             !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "s", &sub))
 685                 goto oom;
 686
 687         NULSTR_FOREACH(i, properties)
 688                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &i))
 689                         goto oom;
 690
 691         if (!dbus_message_iter_close_container(&iter, &sub))
 692                 goto oom;
 693
 694         return m;
 695
 696 oom:
 697         if (m)
 698                 dbus_message_unref(m);
 699
 700         return NULL;
 701 }
 702
 703 uint32_t bus_flags_to_events(DBusWatch *bus_watch) {
 704         unsigned flags;
 705         uint32_t events = 0;
 706
 707         assert(bus_watch);
 708
 709         /* no watch flags for disabled watches */
 710         if (!dbus_watch_get_enabled(bus_watch))
 711                 return 0;
 712
 713         flags = dbus_watch_get_flags(bus_watch);
 714
 715         if (flags & DBUS_WATCH_READABLE)
 716                 events |= EPOLLIN;
 717         if (flags & DBUS_WATCH_WRITABLE)
 718                 events |= EPOLLOUT;
 719
 720         return events | EPOLLHUP | EPOLLERR;
 721 }
 722
 723 unsigned bus_events_to_flags(uint32_t events) {
 724         unsigned flags = 0;
 725
 726         if (events & EPOLLIN)
 727                 flags |= DBUS_WATCH_READABLE;
 728         if (events & EPOLLOUT)
 729                 flags |= DBUS_WATCH_WRITABLE;
 730         if (events & EPOLLHUP)
 731                 flags |= DBUS_WATCH_HANGUP;
 732         if (events & EPOLLERR)
 733                 flags |= DBUS_WATCH_ERROR;
 734
 735         return flags;
 736 }