src/rfkill/rfkill.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Lennart Poettering
   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 <linux/rfkill.h>
  21 #include <poll.h>
  22
  23 #include "libudev.h"
  24 #include "sd-daemon.h"
  25
  26 #include "alloc-util.h"
  27 #include "escape.h"
  28 #include "fd-util.h"
  29 #include "fileio.h"
  30 #include "io-util.h"
  31 #include "mkdir.h"
  32 #include "parse-util.h"
  33 #include "proc-cmdline.h"
  34 #include "string-table.h"
  35 #include "string-util.h"
  36 #include "udev-util.h"
  37 #include "util.h"
  38 #include "list.h"
  39
  40 /* Note that any write is delayed until exit and the rfkill state will not be
  41  * stored for rfkill indices that disappear after a change. */
  42 #define EXIT_USEC (5 * USEC_PER_SEC)
  43
  44 typedef struct write_queue_item {
  45         LIST_FIELDS(struct write_queue_item, queue);
  46         int rfkill_idx;
  47         char *file;
  48         int state;
  49 } write_queue_item;
  50
  51 static void write_queue_item_free(struct write_queue_item *item)
  52 {
  53         assert(item);
  54
  55         free(item->file);
  56         free(item);
  57 }
  58
  59 static const char* const rfkill_type_table[NUM_RFKILL_TYPES] = {
  60         [RFKILL_TYPE_ALL] = "all",
  61         [RFKILL_TYPE_WLAN] = "wlan",
  62         [RFKILL_TYPE_BLUETOOTH] = "bluetooth",
  63         [RFKILL_TYPE_UWB] = "uwb",
  64         [RFKILL_TYPE_WIMAX] = "wimax",
  65         [RFKILL_TYPE_WWAN] = "wwan",
  66         [RFKILL_TYPE_GPS] = "gps",
  67         [RFKILL_TYPE_FM] = "fm",
  68         [RFKILL_TYPE_NFC] = "nfc",
  69 };
  70
  71 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(rfkill_type, int);
  72
  73 static int find_device(
  74                 struct udev *udev,
  75                 const struct rfkill_event *event,
  76                 struct udev_device **ret) {
  77
  78         _cleanup_free_ char *sysname = NULL;
  79         struct udev_device *device;
  80         const char *name;
  81
  82         assert(udev);
  83         assert(event);
  84         assert(ret);
  85
  86         if (asprintf(&sysname, "rfkill%i", event->idx) < 0)
  87                 return log_oom();
  88
  89         device = udev_device_new_from_subsystem_sysname(udev, "rfkill", sysname);
  90         if (!device)
  91                 return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to open device: %m");
  92
  93         name = udev_device_get_sysattr_value(device, "name");
  94         if (!name) {
  95                 log_debug("Device has no name, ignoring.");
  96                 udev_device_unref(device);
  97                 return -ENOENT;
  98         }
  99
 100         log_debug("Operating on rfkill device '%s'.", name);
 101
 102         *ret = device;
 103         return 0;
 104 }
 105
 106 static int wait_for_initialized(
 107                 struct udev *udev,
 108                 struct udev_device *device,
 109                 struct udev_device **ret) {
 110
 111         _cleanup_udev_monitor_unref_ struct udev_monitor *monitor = NULL;
 112         struct udev_device *d;
 113         const char *sysname;
 114         int watch_fd, r;
 115
 116         assert(udev);
 117         assert(device);
 118         assert(ret);
 119
 120         if (udev_device_get_is_initialized(device) != 0) {
 121                 *ret = udev_device_ref(device);
 122                 return 0;
 123         }
 124
 125         assert_se(sysname = udev_device_get_sysname(device));
 126
 127         /* Wait until the device is initialized, so that we can get
 128          * access to the ID_PATH property */
 129
 130         monitor = udev_monitor_new_from_netlink(udev, "udev");
 131         if (!monitor)
 132                 return log_error_errno(errno, "Failed to acquire monitor: %m");
 133
 134         r = udev_monitor_filter_add_match_subsystem_devtype(monitor, "rfkill", NULL);
 135         if (r < 0)
 136                 return log_error_errno(r, "Failed to add rfkill udev match to monitor: %m");
 137
 138         r = udev_monitor_enable_receiving(monitor);
 139         if (r < 0)
 140                 return log_error_errno(r, "Failed to enable udev receiving: %m");
 141
 142         watch_fd = udev_monitor_get_fd(monitor);
 143         if (watch_fd < 0)
 144                 return log_error_errno(watch_fd, "Failed to get watch fd: %m");
 145
 146         /* Check again, maybe things changed */
 147         d = udev_device_new_from_subsystem_sysname(udev, "rfkill", sysname);
 148         if (!d)
 149                 return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to open device: %m");
 150
 151         if (udev_device_get_is_initialized(d) != 0) {
 152                 *ret = d;
 153                 return 0;
 154         }
 155
 156         for (;;) {
 157                 _cleanup_udev_device_unref_ struct udev_device *t = NULL;
 158
 159                 r = fd_wait_for_event(watch_fd, POLLIN, EXIT_USEC);
 160                 if (r == -EINTR)
 161                         continue;
 162                 if (r < 0)
 163                         return log_error_errno(r, "Failed to watch udev monitor: %m");
 164                 if (r == 0) {
 165                         log_error("Timed out waiting for udev monitor.");
 166                         return -ETIMEDOUT;
 167                 }
 168
 169                 t = udev_monitor_receive_device(monitor);
 170                 if (!t)
 171                         continue;
 172
 173                 if (streq_ptr(udev_device_get_sysname(t), sysname)) {
 174                         *ret = udev_device_ref(t);
 175                         return 0;
 176                 }
 177         }
 178 }
 179
 180 static int determine_state_file(
 181                 struct udev *udev,
 182                 const struct rfkill_event *event,
 183                 char **ret) {
 184
 185         _cleanup_udev_device_unref_ struct udev_device *d = NULL;
 186         _cleanup_udev_device_unref_ struct udev_device *device = NULL;
 187         const char *path_id, *type;
 188         char *state_file;
 189         int r;
 190
 191         assert(event);
 192         assert(ret);
 193
 194         r = find_device(udev, event, &d);
 195         if (r < 0)
 196                 return r;
 197
 198         r = wait_for_initialized(udev, d, &device);
 199         if (r < 0)
 200                 return r;
 201
 202         assert_se(type = rfkill_type_to_string(event->type));
 203
 204         path_id = udev_device_get_property_value(device, "ID_PATH");
 205         if (path_id) {
 206                 _cleanup_free_ char *escaped_path_id = NULL;
 207
 208                 escaped_path_id = cescape(path_id);
 209                 if (!escaped_path_id)
 210                         return log_oom();
 211
 212                 state_file = strjoin("/var/lib/systemd/rfkill/", escaped_path_id, ":", type);
 213         } else
 214                 state_file = strjoin("/var/lib/systemd/rfkill/", type);
 215
 216         if (!state_file)
 217                 return log_oom();
 218
 219         *ret = state_file;
 220         return 0;
 221 }
 222
 223 static int load_state(
 224                 int rfkill_fd,
 225                 struct udev *udev,
 226                 const struct rfkill_event *event) {
 227
 228         _cleanup_free_ char *state_file = NULL, *value = NULL;
 229         struct rfkill_event we;
 230         ssize_t l;
 231         int b, r;
 232
 233         assert(rfkill_fd >= 0);
 234         assert(udev);
 235         assert(event);
 236
 237         if (shall_restore_state() == 0)
 238                 return 0;
 239
 240         r = determine_state_file(udev, event, &state_file);
 241         if (r < 0)
 242                 return r;
 243
 244         r = read_one_line_file(state_file, &value);
 245         if (r == -ENOENT) {
 246                 /* No state file? Then save the current state */
 247
 248                 r = write_string_file(state_file, one_zero(event->soft), WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
 249                 if (r < 0)
 250                         return log_error_errno(r, "Failed to write state file %s: %m", state_file);
 251
 252                 log_debug("Saved state '%s' to %s.", one_zero(event->soft), state_file);
 253                 return 0;
 254         }
 255         if (r < 0)
 256                 return log_error_errno(r, "Failed to read state file %s: %m", state_file);
 257
 258         b = parse_boolean(value);
 259         if (b < 0)
 260                 return log_error_errno(b, "Failed to parse state file %s: %m", state_file);
 261
 262         we = (struct rfkill_event) {
 263                 .op = RFKILL_OP_CHANGE,
 264                 .idx = event->idx,
 265                 .soft = b,
 266         };
 267
 268         l = write(rfkill_fd, &we, sizeof(we));
 269         if (l < 0)
 270                 return log_error_errno(errno, "Failed to restore rfkill state for %i: %m", event->idx);
 271         if (l != sizeof(we)) {
 272                 log_error("Couldn't write rfkill event structure, too short.");
 273                 return -EIO;
 274         }
 275
 276         log_debug("Loaded state '%s' from %s.", one_zero(b), state_file);
 277         return 0;
 278 }
 279
 280 static void save_state_queue_remove(
 281                 struct write_queue_item **write_queue,
 282                 int idx,
 283                 char *state_file) {
 284
 285         struct write_queue_item *item, *tmp;
 286
 287         LIST_FOREACH_SAFE(queue, item, tmp, *write_queue) {
 288                 if ((state_file && streq(item->file, state_file)) || idx == item->rfkill_idx) {
 289                         log_debug("Canceled previous save state of '%s' to %s.", one_zero(item->state), item->file);
 290                         LIST_REMOVE(queue, *write_queue, item);
 291                         write_queue_item_free(item);
 292                 }
 293         }
 294 }
 295
 296 static int save_state_queue(
 297                 struct write_queue_item **write_queue,
 298                 int rfkill_fd,
 299                 struct udev *udev,
 300                 const struct rfkill_event *event) {
 301
 302         _cleanup_free_ char *state_file = NULL;
 303         struct write_queue_item *item;
 304         int r;
 305
 306         assert(rfkill_fd >= 0);
 307         assert(udev);
 308         assert(event);
 309
 310         r = determine_state_file(udev, event, &state_file);
 311         if (r < 0)
 312                 return r;
 313         save_state_queue_remove(write_queue, event->idx, state_file);
 314
 315         item = new0(struct write_queue_item, 1);
 316         if (!item)
 317                 return -ENOMEM;
 318
 319         item->file = state_file;
 320         item->rfkill_idx = event->idx;
 321         item->state = event->soft;
 322         state_file = NULL;
 323
 324         LIST_APPEND(queue, *write_queue, item);
 325
 326         return 0;
 327 }
 328
 329 static int save_state_cancel(
 330                 struct write_queue_item **write_queue,
 331                 int rfkill_fd,
 332                 struct udev *udev,
 333                 const struct rfkill_event *event) {
 334
 335         _cleanup_free_ char *state_file = NULL;
 336         int r;
 337
 338         assert(rfkill_fd >= 0);
 339         assert(udev);
 340         assert(event);
 341
 342         r = determine_state_file(udev, event, &state_file);
 343         save_state_queue_remove(write_queue, event->idx, state_file);
 344         if (r < 0)
 345                 return r;
 346
 347         return 0;
 348 }
 349
 350 static int save_state_write(struct write_queue_item **write_queue) {
 351         struct write_queue_item *item, *tmp;
 352         int result = 0;
 353         bool error_logged = false;
 354         int r;
 355
 356         LIST_FOREACH_SAFE(queue, item, tmp, *write_queue) {
 357                 r = write_string_file(item->file, one_zero(item->state), WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
 358                 if (r < 0) {
 359                         result = r;
 360                         if (!error_logged) {
 361                                 log_error_errno(r, "Failed to write state file %s: %m", item->file);
 362                                 error_logged = true;
 363                         } else
 364                                 log_warning_errno(r, "Failed to write state file %s: %m", item->file);
 365                 } else
 366                         log_debug("Saved state '%s' to %s.", one_zero(item->state), item->file);
 367
 368                 LIST_REMOVE(queue, *write_queue, item);
 369                 write_queue_item_free(item);
 370         }
 371         return result;
 372 }
 373
 374 int main(int argc, char *argv[]) {
 375         LIST_HEAD(write_queue_item, write_queue);
 376         _cleanup_udev_unref_ struct udev *udev = NULL;
 377         _cleanup_close_ int rfkill_fd = -1;
 378         bool ready = false;
 379         int r, n;
 380
 381         if (argc > 1) {
 382                 log_error("This program requires no arguments.");
 383                 return EXIT_FAILURE;
 384         }
 385
 386         LIST_HEAD_INIT(write_queue);
 387
 388         log_set_target(LOG_TARGET_AUTO);
 389         log_parse_environment();
 390         log_open();
 391
 392         umask(0022);
 393
 394         udev = udev_new();
 395         if (!udev) {
 396                 r = log_oom();
 397                 goto finish;
 398         }
 399
 400         r = mkdir_p("/var/lib/systemd/rfkill", 0755);
 401         if (r < 0) {
 402                 log_error_errno(r, "Failed to create rfkill directory: %m");
 403                 goto finish;
 404         }
 405
 406         n = sd_listen_fds(false);
 407         if (n < 0) {
 408                 r = log_error_errno(n, "Failed to determine whether we got any file descriptors passed: %m");
 409                 goto finish;
 410         }
 411         if (n > 1) {
 412                 log_error("Got too many file descriptors.");
 413                 r = -EINVAL;
 414                 goto finish;
 415         }
 416
 417         if (n == 0) {
 418                 rfkill_fd = open("/dev/rfkill", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
 419                 if (rfkill_fd < 0) {
 420                         if (errno == ENOENT) {
 421                                 log_debug_errno(errno, "Missing rfkill subsystem, or no device present, exiting.");
 422                                 r = 0;
 423                                 goto finish;
 424                         }
 425
 426                         r = log_error_errno(errno, "Failed to open /dev/rfkill: %m");
 427                         goto finish;
 428                 }
 429         } else {
 430                 rfkill_fd = SD_LISTEN_FDS_START;
 431
 432                 r = fd_nonblock(rfkill_fd, 1);
 433                 if (r < 0) {
 434                         log_error_errno(r, "Failed to make /dev/rfkill socket non-blocking: %m");
 435                         goto finish;
 436                 }
 437         }
 438
 439         for (;;) {
 440                 struct rfkill_event event;
 441                 const char *type;
 442                 ssize_t l;
 443
 444                 l = read(rfkill_fd, &event, sizeof(event));
 445                 if (l < 0) {
 446                         if (errno == EAGAIN) {
 447
 448                                 if (!ready) {
 449                                         /* Notify manager that we are
 450                                          * now finished with
 451                                          * processing whatever was
 452                                          * queued */
 453                                         (void) sd_notify(false, "READY=1");
 454                                         ready = true;
 455                                 }
 456
 457                                 /* Hang around for a bit, maybe there's more coming */
 458
 459                                 r = fd_wait_for_event(rfkill_fd, POLLIN, EXIT_USEC);
 460                                 if (r == -EINTR)
 461                                         continue;
 462                                 if (r < 0) {
 463                                         log_error_errno(r, "Failed to poll() on device: %m");
 464                                         goto finish;
 465                                 }
 466                                 if (r > 0)
 467                                         continue;
 468
 469                                 log_debug("All events read and idle, exiting.");
 470                                 break;
 471                         }
 472
 473                         log_error_errno(errno, "Failed to read from /dev/rfkill: %m");
 474                 }
 475
 476                 if (l != RFKILL_EVENT_SIZE_V1) {
 477                         log_error("Read event structure of invalid size.");
 478                         r = -EIO;
 479                         goto finish;
 480                 }
 481
 482                 type = rfkill_type_to_string(event.type);
 483                 if (!type) {
 484                         log_debug("An rfkill device of unknown type %i discovered, ignoring.", event.type);
 485                         continue;
 486                 }
 487
 488                 switch (event.op) {
 489
 490                 case RFKILL_OP_ADD:
 491                         log_debug("A new rfkill device has been added with index %i and type %s.", event.idx, type);
 492                         (void) load_state(rfkill_fd, udev, &event);
 493                         break;
 494
 495                 case RFKILL_OP_DEL:
 496                         log_debug("An rfkill device has been removed with index %i and type %s", event.idx, type);
 497                         (void) save_state_cancel(&write_queue, rfkill_fd, udev, &event);
 498                         break;
 499
 500                 case RFKILL_OP_CHANGE:
 501                         log_debug("An rfkill device has changed state with index %i and type %s", event.idx, type);
 502                         (void) save_state_queue(&write_queue, rfkill_fd, udev, &event);
 503                         break;
 504
 505                 default:
 506                         log_debug("Unknown event %i from /dev/rfkill for index %i and type %s, ignoring.", event.op, event.idx, type);
 507                         break;
 508                 }
 509         }
 510
 511         r = 0;
 512
 513 finish:
 514         (void) save_state_write(&write_queue);
 515
 516         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 517 }