src/bus-driverd/bus-driverd.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Daniel Mack
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdlib.h>
  21 #include <stdbool.h>
  22 #include <unistd.h>
  23 #include <getopt.h>
  24 #include <locale.h>
  25 #include <string.h>
  26 #include <poll.h>
  27 #include <netdb.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <sys/timex.h>
  31 #include <sys/utsname.h>
  32 #include <unistd.h>
  33
  34 #include "kdbus.h"
  35 #include "sd-bus.h"
  36 #include "bus-internal.h"
  37 #include "sd-daemon.h"
  38 #include "sd-event.h"
  39 #include "event-util.h"
  40 #include "bus-util.h"
  41 #include "bus-error.h"
  42 #include "bus-message.h"
  43 #include "bus-kernel.h"
  44 #include "socket-util.h"
  45 #include "util.h"
  46 #include "build.h"
  47 #include "strv.h"
  48 #include "sd-id128.h"
  49 #include "async.h"
  50 #include "hashmap.h"
  51 #include "def.h"
  52 #include "unit-name.h"
  53
  54 /*
  55  * TODO:
  56  *
  57  * AddMatch / RemoveMatch
  58  */
  59
  60 static int driver_add_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
  61
  62         char *arg0;
  63         int r;
  64
  65         r = sd_bus_message_read(m, "s", &arg0);
  66         if (r < 0)
  67                 return r;
  68
  69         /* FIXME */
  70
  71         return sd_bus_reply_method_return(m, NULL);
  72 }
  73
  74 static int driver_remove_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
  75         char *arg0;
  76         int r;
  77
  78         r = sd_bus_message_read(m, "s", &arg0);
  79         if (r < 0)
  80                 return r;
  81
  82         /* FIXME */
  83
  84         return sd_bus_reply_method_return(m, NULL);
  85 }
  86
  87 static int driver_get_security_ctx(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
  88         _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
  89         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
  90         char *arg0;
  91         int r;
  92
  93         r = sd_bus_message_read(m, "s", &arg0);
  94         if (r < 0)
  95                 return r;
  96
  97         assert_return(service_name_is_valid(arg0), -EINVAL);
  98
  99         r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_SELINUX_CONTEXT, &creds);
 100         if (r < 0)
 101                 return r;
 102
 103         r = sd_bus_message_new_method_return(m, &reply);
 104         if (r < 0)
 105                 return r;
 106
 107         r = sd_bus_message_append_array(reply, 'y', creds->label, strlen(creds->label));
 108         if (r < 0)
 109                 return r;
 110
 111         return sd_bus_send(bus, reply, NULL);
 112 }
 113
 114 static int driver_get_pid(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 115         _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
 116         char *arg0;
 117         int r;
 118
 119         r = sd_bus_message_read(m, "s", &arg0);
 120         if (r < 0)
 121                 return r;
 122
 123         assert_return(service_name_is_valid(arg0), -EINVAL);
 124
 125         r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_PID, &creds);
 126         if (r < 0)
 127                 return r;
 128
 129         return sd_bus_reply_method_return(m, "u", creds->pid);
 130 }
 131
 132 static int driver_get_user(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 133         _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
 134         char *arg0;
 135         int r;
 136
 137         r = sd_bus_message_read(m, "s", &arg0);
 138         if (r < 0)
 139                 return r;
 140
 141         assert_return(service_name_is_valid(arg0), -EINVAL);
 142
 143         r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_UID, &creds);
 144         if (r < 0)
 145                 return r;
 146
 147         return sd_bus_reply_method_return(m, "u", creds->uid);
 148 }
 149
 150 static int driver_get_id(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 151         sd_id128_t server_id;
 152         char buf[SD_ID128_STRING_MAX];
 153         int r;
 154
 155         r = sd_bus_get_server_id(bus, &server_id);
 156         if (r < 0)
 157                 return r;
 158
 159         return sd_bus_reply_method_return(m, "s", sd_id128_to_string(server_id, buf));
 160 }
 161
 162 static int driver_get_name_owner(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 163         _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
 164         char *arg0;
 165         int r;
 166
 167         r = sd_bus_message_read(m, "s", &arg0);
 168         if (r < 0)
 169                 return r;
 170
 171         assert_return(service_name_is_valid(arg0), -EINVAL);
 172
 173         r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_UNIQUE_NAME, &creds);
 174         if (r < 0)
 175                 return r;
 176
 177         return sd_bus_reply_method_return(m, "s", creds->unique_name);
 178 }
 179
 180 static int driver_hello(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 181         return sd_bus_reply_method_return(m, "s", m->sender);
 182 }
 183
 184 static int return_strv(sd_bus *bus, sd_bus_message *m, char **l) {
 185         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
 186         int r;
 187
 188         r = sd_bus_message_new_method_return(m, &reply);
 189         if (r < 0)
 190                 return r;
 191
 192         r = sd_bus_message_append_strv(reply, l);
 193         if (r < 0)
 194                 return r;
 195
 196         return sd_bus_send(bus, reply, NULL);
 197 }
 198
 199 static int driver_list_names(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 200         _cleanup_strv_free_ char **names = NULL;
 201         int r;
 202
 203         r = sd_bus_list_names(bus, &names, NULL);
 204         if (r < 0)
 205                 return r;
 206
 207         return return_strv(bus, m, names);
 208 }
 209
 210 static int driver_list_activatable_names(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 211         _cleanup_strv_free_ char **names = NULL;
 212         int r;
 213
 214         r = sd_bus_list_names(bus, NULL, &names);
 215         if (r < 0)
 216                 return r;
 217
 218         return return_strv(bus, m, names);
 219 }
 220
 221 static int driver_list_queued_owners(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 222         struct kdbus_cmd_name_list cmd = {};
 223         struct kdbus_name_list *name_list;
 224         struct kdbus_cmd_name *name;
 225         _cleanup_strv_free_ char **owners = NULL;
 226         char *arg0;
 227         int r;
 228
 229         r = sd_bus_message_read(m, "s", &arg0);
 230         if (r < 0)
 231                 return r;
 232
 233         assert_return(service_name_is_valid(arg0), -EINVAL);
 234
 235         cmd.flags = KDBUS_NAME_LIST_QUEUED;
 236
 237         r = ioctl(bus->input_fd, KDBUS_CMD_NAME_LIST, &cmd);
 238         if (r < 0)
 239                 return -errno;
 240
 241         name_list = (struct kdbus_name_list *) ((uint8_t *) bus->kdbus_buffer + cmd.offset);
 242
 243         KDBUS_ITEM_FOREACH(name, name_list, names) {
 244                 char *n;
 245
 246                 if (name->size <= sizeof(*name))
 247                         continue;
 248
 249                 if (!streq(name->name, arg0))
 250                         continue;
 251
 252                 if (asprintf(&n, ":1.%llu", (unsigned long long) name->id) < 0)
 253                         return -ENOMEM;
 254
 255                 r = strv_push(&owners, n);
 256                 if (r < 0) {
 257                         free(n);
 258                         return -ENOMEM;
 259                 }
 260         }
 261
 262         r = ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd.offset);
 263         if (r < 0)
 264                 return -errno;
 265
 266         return return_strv(bus, m, owners);
 267 }
 268
 269 static int driver_name_has_owner(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 270         char *arg0;
 271         int r;
 272
 273         r = sd_bus_message_read(m, "s", &arg0);
 274         if (r < 0)
 275                 return r;
 276
 277         assert_return(service_name_is_valid(arg0), -EINVAL);
 278
 279         r = sd_bus_get_owner(bus, arg0, 0, NULL);
 280         if (r < 0 && r != -ENOENT)
 281                 return r;
 282
 283         return sd_bus_reply_method_return(m, "b", r >= 0);
 284 }
 285
 286 static int driver_request_name(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 287         struct kdbus_cmd_name *n;
 288         uint32_t flags;
 289         size_t size, l;
 290         uint64_t id;
 291         const char *name;
 292         int r;
 293
 294         r = sd_bus_message_read(m, "su", &name, &flags);
 295         if (r < 0)
 296                 return r;
 297
 298         assert_return(service_name_is_valid(name), -EINVAL);
 299         assert_return((flags & ~(BUS_NAME_ALLOW_REPLACEMENT|BUS_NAME_REPLACE_EXISTING|BUS_NAME_DO_NOT_QUEUE)) == 0, -EINVAL);
 300
 301         l = strlen(name);
 302         size = offsetof(struct kdbus_cmd_name, name) + l + 1;
 303         n = alloca0(size);
 304         n->size = size;
 305         memcpy(n->name, name, l+1);
 306         kdbus_translate_request_name_flags(flags, (uint64_t *) &n->flags);
 307
 308         /* This function is open-coded because we request the name 'on behalf'
 309          * of the requesting connection */
 310         r = bus_kernel_parse_unique_name(m->sender, &id);
 311         if (r < 0)
 312                 return r;
 313
 314         n->id = id;
 315
 316         r = ioctl(bus->input_fd, KDBUS_CMD_NAME_ACQUIRE, n);
 317         if (r < 0) {
 318                 if (errno == EEXIST)
 319                         return sd_bus_reply_method_return(m, "u", BUS_NAME_EXISTS);
 320                 if (errno == EALREADY)
 321                         return sd_bus_reply_method_return(m, "u", BUS_NAME_ALREADY_OWNER);
 322
 323                 return -errno;
 324         }
 325
 326         if (n->flags & KDBUS_NAME_IN_QUEUE)
 327                 return sd_bus_reply_method_return(m, "u", BUS_NAME_IN_QUEUE);
 328
 329         return sd_bus_reply_method_return(m, "u", BUS_NAME_PRIMARY_OWNER);
 330 }
 331
 332 static int driver_release_name(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 333         struct kdbus_cmd_name *n;
 334         const char *name;
 335         size_t l, size;
 336         uint64_t id;
 337         int r;
 338
 339         r = sd_bus_message_read(m, "s", &name);
 340         if (r < 0)
 341                 return r;
 342
 343         assert_return(service_name_is_valid(name), -EINVAL);
 344
 345         l = strlen(name);
 346         size = offsetof(struct kdbus_cmd_name, name) + l + 1;
 347         n = alloca0(size);
 348         n->size = size;
 349         memcpy(n->name, name, l+1);
 350
 351         /* This function is open-coded because we request the name 'on behalf'
 352          * of the requesting connection */
 353         r = bus_kernel_parse_unique_name(m->sender, &id);
 354         if (r < 0)
 355                 return r;
 356
 357         n->id = id;
 358
 359         r = ioctl(bus->input_fd, KDBUS_CMD_NAME_RELEASE, n);
 360         if (r < 0) {
 361                 if (errno == ESRCH)
 362                         return sd_bus_reply_method_return(m, "u", BUS_NAME_NON_EXISTENT);
 363                 if (errno == EADDRINUSE)
 364                         return sd_bus_reply_method_return(m, "u", BUS_NAME_NOT_OWNER);
 365                 return -errno;
 366         }
 367
 368         return sd_bus_reply_method_return(m, "u", BUS_NAME_RELEASED);
 369 }
 370
 371 static int driver_start_service_by_name(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 372         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
 373         _cleanup_strv_free_ char **t = NULL;
 374         _cleanup_free_ char *path = NULL;
 375         uint32_t flags;
 376         char *name, *u;
 377         int r;
 378
 379         r = sd_bus_message_read(m, "su", &name, &flags);
 380         if (r < 0)
 381                 return r;
 382
 383         assert_return(service_name_is_valid(name), -EINVAL);
 384         assert_return(flags == 0, -ENOTSUP);
 385
 386         r = sd_bus_get_owner(bus, name, 0, NULL);
 387         if (r >= 0)
 388                 return sd_bus_reply_method_return(m, "u", BUS_START_REPLY_ALREADY_RUNNING);
 389         if (r != -ENOENT)
 390                 return r;
 391
 392         u = strappenda(name, ".busname");
 393
 394         path = unit_dbus_path_from_name(u);
 395         if (!path)
 396                 return -ENOMEM;
 397
 398         r = sd_bus_get_property_strv(
 399                         bus,
 400                         "org.freedesktop.systemd1",
 401                         path,
 402                         "org.freedesktop.systemd1.Unit",
 403                         "Triggers",
 404                         error,
 405                         &t);
 406         if (r < 0)
 407                 return r;
 408
 409         if (!t[0] || t[1])
 410                 return -EIO;
 411
 412         r = sd_bus_call_method(
 413                         bus,
 414                         "org.freedesktop.systemd1",
 415                         "/org/freedesktop/systemd1",
 416                         "org.freedesktop.systemd1.Manager",
 417                         "StartUnit",
 418                         error,
 419                         &reply,
 420                         "ss",
 421                         t[0],
 422                         "replace");
 423         if (r < 0)
 424                 return r;
 425
 426         return sd_bus_reply_method_return(m, "u", BUS_START_REPLY_SUCCESS);
 427 }
 428
 429 static int driver_unsupported(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
 430         return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "%s() is not supported", sd_bus_message_get_member(m));
 431 }
 432
 433 static const sd_bus_vtable driver_vtable[] = {
 434         SD_BUS_VTABLE_START(0),
 435         SD_BUS_METHOD("AddMatch", "s", NULL, driver_add_match, 0),
 436         SD_BUS_METHOD("GetConnectionSELinuxSecurityContext", "s", "ay", driver_get_security_ctx, SD_BUS_VTABLE_UNPRIVILEGED),
 437         SD_BUS_METHOD("GetConnectionUnixProcessID", "s", "u", driver_get_pid, SD_BUS_VTABLE_UNPRIVILEGED),
 438         SD_BUS_METHOD("GetConnectionUnixUser", "s", "u", driver_get_user, SD_BUS_VTABLE_UNPRIVILEGED),
 439         SD_BUS_METHOD("GetId", NULL, "s", driver_get_id, SD_BUS_VTABLE_UNPRIVILEGED),
 440         SD_BUS_METHOD("GetNameOwner", "s", "s", driver_get_name_owner, SD_BUS_VTABLE_UNPRIVILEGED),
 441         SD_BUS_METHOD("Hello", NULL, "s", driver_hello, SD_BUS_VTABLE_UNPRIVILEGED),
 442         SD_BUS_METHOD("ListActivatableNames", NULL, "as", driver_list_activatable_names, SD_BUS_VTABLE_UNPRIVILEGED),
 443         SD_BUS_METHOD("ListNames", NULL, "as", driver_list_names, SD_BUS_VTABLE_UNPRIVILEGED),
 444         SD_BUS_METHOD("ListQueuedOwners", "s", "as", driver_list_queued_owners, SD_BUS_VTABLE_UNPRIVILEGED),
 445         SD_BUS_METHOD("NameHasOwner", "s", "b", driver_name_has_owner, SD_BUS_VTABLE_UNPRIVILEGED),
 446         SD_BUS_METHOD("ReleaseName", "s", "u", driver_release_name, SD_BUS_VTABLE_UNPRIVILEGED),
 447         SD_BUS_METHOD("ReloadConfig", NULL, NULL, driver_unsupported, SD_BUS_VTABLE_DEPRECATED),
 448         SD_BUS_METHOD("RemoveMatch", "s", NULL, driver_remove_match, SD_BUS_VTABLE_UNPRIVILEGED),
 449         SD_BUS_METHOD("RequestName", "su", "u", driver_request_name, SD_BUS_VTABLE_UNPRIVILEGED),
 450         SD_BUS_METHOD("StartServiceByName", "su", "u", driver_start_service_by_name, SD_BUS_VTABLE_UNPRIVILEGED),
 451         SD_BUS_METHOD("UpdateActivationEnvironment", "a{ss}", NULL, driver_unsupported, SD_BUS_VTABLE_DEPRECATED),
 452         SD_BUS_SIGNAL("NameAcquired", "s", SD_BUS_VTABLE_DEPRECATED),
 453         SD_BUS_SIGNAL("NameLost", "s", SD_BUS_VTABLE_DEPRECATED),
 454         SD_BUS_SIGNAL("NameOwnerChanged", "sss", 0),
 455         SD_BUS_VTABLE_END
 456 };
 457
 458 static int connect_bus(sd_event *event, sd_bus **_bus) {
 459         _cleanup_bus_unref_ sd_bus *bus = NULL;
 460         int r;
 461
 462         assert(event);
 463         assert(_bus);
 464
 465         r = sd_bus_default_system(&bus);
 466         if (r < 0) {
 467                 log_error("Failed to create bus: %s", strerror(-r));
 468                 return r;
 469         }
 470
 471         if (!bus->is_kernel) {
 472                 log_error("Not running on kdbus");
 473                 return -EPERM;
 474         }
 475
 476         r = sd_bus_add_object_vtable(bus, "/org/freedesktop/DBus", "org.freedesktop.DBus", driver_vtable, NULL);
 477         if (r < 0) {
 478                 log_error("Failed to add manager object vtable: %s", strerror(-r));
 479                 return r;
 480         }
 481
 482         r = sd_bus_request_name(bus, "org.freedesktop.DBus", 0);
 483         if (r < 0) {
 484                 log_error("Unable to request name: %s\n", strerror(-r));
 485                 return r;
 486         }
 487
 488         r = sd_bus_attach_event(bus, event, 0);
 489         if (r < 0) {
 490                 log_error("Error %d while adding bus to even: %s", r, strerror(-r));
 491                 return r;
 492         }
 493
 494         *_bus = bus;
 495         bus = NULL;
 496
 497         return 0;
 498 }
 499
 500 int main(int argc, char *argv[]) {
 501         _cleanup_event_unref_ sd_event *event = NULL;
 502         _cleanup_bus_unref_ sd_bus *bus = NULL;
 503         int r;
 504
 505         log_set_target(LOG_TARGET_AUTO);
 506         log_parse_environment();
 507         log_open();
 508
 509         if (argc != 1) {
 510                 log_error("This program takes no arguments.");
 511                 r = -EINVAL;
 512                 goto finish;
 513         }
 514
 515         r = sd_event_default(&event);
 516         if (r < 0) {
 517                 log_error("Failed to allocate event loop: %s", strerror(-r));
 518                 goto finish;
 519         }
 520
 521         sd_event_set_watchdog(event, true);
 522
 523         r = connect_bus(event, &bus);
 524         if (r < 0)
 525                 goto finish;
 526
 527         r = bus_event_loop_with_idle(event, bus, "org.freedesktop.DBus", DEFAULT_EXIT_USEC);
 528         if (r < 0) {
 529                 log_error("Failed to run event loop: %s", strerror(-r));
 530                 goto finish;
 531         }
 532
 533 finish:
 534         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 535
 536 }