code.delx.au - pulseaudio/blob - src/modules/module-udev-detect.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2009 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio 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   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <limits.h>
  28 #include <sys/inotify.h>
  29 #include <libudev.h>
  30
  31 #include <pulsecore/modargs.h>
  32 #include <pulsecore/core-error.h>
  33 #include <pulsecore/core-util.h>
  34 #include <pulsecore/namereg.h>
  35
  36 #include "module-udev-detect-symdef.h"
  37
  38 PA_MODULE_AUTHOR("Lennart Poettering");
  39 PA_MODULE_DESCRIPTION("Detect available audio hardware and load matching drivers");
  40 PA_MODULE_VERSION(PACKAGE_VERSION);
  41 PA_MODULE_LOAD_ONCE(TRUE);
  42 PA_MODULE_USAGE(
  43         "tsched=<enable system timer based scheduling mode?> "
  44         "ignore_dB=<ignore dB information from the device?>");
  45
  46 struct device {
  47     char *path;
  48     pa_bool_t accessible:1;
  49     pa_bool_t need_verify:1;
  50     char *card_name;
  51     char *args;
  52     uint32_t module;
  53 };
  54
  55 struct userdata {
  56     pa_core *core;
  57     pa_hashmap *devices;
  58
  59     pa_bool_t use_tsched:1;
  60     pa_bool_t ignore_dB:1;
  61
  62     struct udev* udev;
  63     struct udev_monitor *monitor;
  64     pa_io_event *udev_io;
  65
  66     int inotify_fd;
  67     pa_io_event *inotify_io;
  68 };
  69
  70 static const char* const valid_modargs[] = {
  71     "tsched",
  72     "ignore_dB",
  73     NULL
  74 };
  75
  76 static int setup_inotify(struct userdata *u);
  77
  78 static void device_free(struct device *d) {
  79     pa_assert(d);
  80
  81     pa_xfree(d->path);
  82     pa_xfree(d->card_name);
  83     pa_xfree(d->args);
  84     pa_xfree(d);
  85 }
  86
  87 static const char *path_get_card_id(const char *path) {
  88     const char *e;
  89
  90     if (!path)
  91         return NULL;
  92
  93     if (!(e = strrchr(path, '/')))
  94         return NULL;
  95
  96     if (!pa_startswith(e, "/card"))
  97         return NULL;
  98
  99     return e + 5;
 100 }
 101
 102 static void verify_access(struct userdata *u, struct device *d) {
 103     char *cd;
 104     pa_card *card;
 105
 106     pa_assert(u);
 107     pa_assert(d);
 108
 109     cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
 110     d->accessible = access(cd, R_OK|W_OK) >= 0;
 111
 112     pa_log_info("%s is accessible: %s", cd, pa_yes_no(d->accessible));
 113     pa_xfree(cd);
 114
 115     if (d->module == PA_INVALID_INDEX) {
 116
 117         /* If we not loaded, try to load */
 118
 119         if (d->accessible) {
 120             pa_module *m;
 121
 122             pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
 123             m = pa_module_load(u->core, "module-alsa-card", d->args);
 124
 125             if (m) {
 126                 d->module = m->index;
 127                 pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
 128             } else
 129                 pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
 130         }
 131
 132     } else {
 133
 134         /* If we are already loaded update suspend status with
 135          * accessible boolean */
 136
 137         if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 138             pa_card_suspend(card, !d->accessible, PA_SUSPEND_SESSION);
 139     }
 140 }
 141
 142 static void card_changed(struct userdata *u, struct udev_device *dev) {
 143     struct device *d;
 144     const char *path;
 145     const char *t;
 146     char *n;
 147
 148     pa_assert(u);
 149     pa_assert(dev);
 150
 151     /* Maybe /dev/snd is now available? */
 152     setup_inotify(u);
 153
 154     path = udev_device_get_devpath(dev);
 155
 156     if ((d = pa_hashmap_get(u->devices, path))) {
 157         verify_access(u, d);
 158         return;
 159     }
 160
 161     d = pa_xnew0(struct device, 1);
 162     d->path = pa_xstrdup(path);
 163     d->accessible = TRUE;
 164     d->module = PA_INVALID_INDEX;
 165
 166     if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
 167         if (!(t = udev_device_get_property_value(dev, "ID_ID")))
 168             if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
 169                 t = path_get_card_id(path);
 170
 171     n = pa_namereg_make_valid_name(t);
 172     d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
 173     d->args = pa_sprintf_malloc("device_id=\"%s\" "
 174                                 "name=\"%s\" "
 175                                 "card_name=\"%s\" "
 176                                 "tsched=%s "
 177                                 "ignore_dB=%s "
 178                                 "card_properties=\"module-udev-detect.discovered=1\"",
 179                                 path_get_card_id(path),
 180                                 n,
 181                                 d->card_name,
 182                                 pa_yes_no(u->use_tsched),
 183                                 pa_yes_no(u->ignore_dB));
 184     pa_xfree(n);
 185
 186     pa_hashmap_put(u->devices, d->path, d);
 187
 188     verify_access(u, d);
 189 }
 190
 191 static void remove_card(struct userdata *u, struct udev_device *dev) {
 192     struct device *d;
 193
 194     pa_assert(u);
 195     pa_assert(dev);
 196
 197     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 198         return;
 199
 200     pa_log_info("Card %s removed.", d->path);
 201
 202     if (d->module != PA_INVALID_INDEX)
 203         pa_module_unload_request_by_index(u->core, d->module, TRUE);
 204
 205     device_free(d);
 206 }
 207
 208 static void process_device(struct userdata *u, struct udev_device *dev) {
 209     const char *action, *ff;
 210
 211     pa_assert(u);
 212     pa_assert(dev);
 213
 214     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 215         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 216         return;
 217     }
 218
 219     if ((ff = udev_device_get_property_value(dev, "SOUND_FORM_FACTOR")) &&
 220         pa_streq(ff, "modem")) {
 221         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 222         return;
 223     }
 224
 225     action = udev_device_get_action(dev);
 226
 227     if (action && pa_streq(action, "remove"))
 228         remove_card(u, dev);
 229     else if ((!action || pa_streq(action, "change")) &&
 230              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 231         card_changed(u, dev);
 232
 233     /* For an explanation why we don't look for 'add' events here
 234      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 235 }
 236
 237 static void process_path(struct userdata *u, const char *path) {
 238     struct udev_device *dev;
 239
 240     if (!path_get_card_id(path))
 241         return;
 242
 243     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 244         pa_log("Failed to get udev device object from udev.");
 245         return;
 246     }
 247
 248     process_device(u, dev);
 249     udev_device_unref(dev);
 250 }
 251
 252 static void monitor_cb(
 253         pa_mainloop_api*a,
 254         pa_io_event* e,
 255         int fd,
 256         pa_io_event_flags_t events,
 257         void *userdata) {
 258
 259     struct userdata *u = userdata;
 260     struct udev_device *dev;
 261
 262     pa_assert(a);
 263
 264     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 265         pa_log("Failed to get udev device object from monitor.");
 266         goto fail;
 267     }
 268
 269     if (!path_get_card_id(udev_device_get_devpath(dev)))
 270         return;
 271
 272     process_device(u, dev);
 273     udev_device_unref(dev);
 274     return;
 275
 276 fail:
 277     a->io_free(u->udev_io);
 278     u->udev_io = NULL;
 279 }
 280
 281 static pa_bool_t pcm_node_belongs_to_device(
 282         struct device *d,
 283         const char *node) {
 284
 285     char *cd;
 286     pa_bool_t b;
 287
 288     cd = pa_sprintf_malloc("pcmC%sD", path_get_card_id(d->path));
 289     b = pa_startswith(node, cd);
 290     pa_xfree(cd);
 291
 292     return b;
 293 }
 294
 295 static pa_bool_t control_node_belongs_to_device(
 296         struct device *d,
 297         const char *node) {
 298
 299     char *cd;
 300     pa_bool_t b;
 301
 302     cd = pa_sprintf_malloc("controlC%s", path_get_card_id(d->path));
 303     b = pa_streq(node, cd);
 304     pa_xfree(cd);
 305
 306     return b;
 307 }
 308
 309 static void inotify_cb(
 310         pa_mainloop_api*a,
 311         pa_io_event* e,
 312         int fd,
 313         pa_io_event_flags_t events,
 314         void *userdata) {
 315
 316     struct {
 317         struct inotify_event e;
 318         char name[NAME_MAX];
 319     } buf;
 320     struct userdata *u = userdata;
 321     static int type = 0;
 322     pa_bool_t deleted = FALSE;
 323     struct device *d;
 324     void *state;
 325
 326     for (;;) {
 327         ssize_t r;
 328         struct inotify_event *event;
 329
 330         pa_zero(buf);
 331         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 332
 333             if (r < 0 && errno == EAGAIN)
 334                 break;
 335
 336             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 337             goto fail;
 338         }
 339
 340         event = &buf.e;
 341         while (r > 0) {
 342             size_t len;
 343
 344             if ((size_t) r < sizeof(struct inotify_event)) {
 345                 pa_log("read() too short.");
 346                 goto fail;
 347             }
 348
 349             len = sizeof(struct inotify_event) + event->len;
 350
 351             if ((size_t) r < len) {
 352                 pa_log("Payload missing.");
 353                 goto fail;
 354             }
 355
 356             /* From udev we get the guarantee that the control
 357              * device's ACL is changed last. To avoid races when ACLs
 358              * are changed we hence watch only the control device */
 359             if (((event->mask & IN_ATTRIB) && pa_startswith(event->name, "controlC")))
 360                 PA_HASHMAP_FOREACH(d, u->devices, state)
 361                     if (control_node_belongs_to_device(d, event->name))
 362                         d->need_verify = TRUE;
 363
 364             /* ALSA doesn't really give us any guarantee on the closing
 365              * order, so let's simply hope */
 366             if (((event->mask & IN_CLOSE_WRITE) && pa_startswith(event->name, "pcmC")))
 367                 PA_HASHMAP_FOREACH(d, u->devices, state)
 368                     if (pcm_node_belongs_to_device(d, event->name))
 369                         d->need_verify = TRUE;
 370
 371             /* /dev/snd/ might have been removed */
 372             if ((event->mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 373                 deleted = TRUE;
 374
 375             event = (struct inotify_event*) ((uint8_t*) event + len);
 376             r -= len;
 377         }
 378     }
 379
 380     PA_HASHMAP_FOREACH(d, u->devices, state)
 381         if (d->need_verify) {
 382             d->need_verify = FALSE;
 383             verify_access(u, d);
 384         }
 385
 386     if (!deleted)
 387         return;
 388
 389 fail:
 390     if (u->inotify_io) {
 391         a->io_free(u->inotify_io);
 392         u->inotify_io = NULL;
 393     }
 394
 395     if (u->inotify_fd >= 0) {
 396         pa_close(u->inotify_fd);
 397         u->inotify_fd = -1;
 398     }
 399 }
 400
 401 static int setup_inotify(struct userdata *u) {
 402     char *dev_snd;
 403     int r;
 404
 405     if (u->inotify_fd >= 0)
 406         return 0;
 407
 408     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 409         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 410         return -1;
 411     }
 412
 413     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 414     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_ATTRIB|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 415     pa_xfree(dev_snd);
 416
 417     if (r < 0) {
 418         int saved_errno = errno;
 419
 420         pa_close(u->inotify_fd);
 421         u->inotify_fd = -1;
 422
 423         if (saved_errno == ENOENT) {
 424             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 425             return 0;
 426         }
 427
 428         if (saved_errno == ENOSPC) {
 429             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 430                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 431                    "directory trees which is something the current inotify is certainly not useful for. "
 432                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 433             return 0;
 434         }
 435
 436         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 437         return -1;
 438     }
 439
 440     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 441
 442     return 0;
 443 }
 444
 445 int pa__init(pa_module *m) {
 446     struct userdata *u = NULL;
 447     pa_modargs *ma;
 448     struct udev_enumerate *enumerate = NULL;
 449     struct udev_list_entry *item = NULL, *first = NULL;
 450     int fd;
 451     pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
 452
 453     pa_assert(m);
 454
 455     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 456         pa_log("Failed to parse module arguments");
 457         goto fail;
 458     }
 459
 460     m->userdata = u = pa_xnew0(struct userdata, 1);
 461     u->core = m->core;
 462     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 463     u->inotify_fd = -1;
 464
 465     if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
 466         pa_log("Failed to parse tsched= argument.");
 467         goto fail;
 468     }
 469     u->use_tsched = use_tsched;
 470
 471     if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
 472         pa_log("Failed to parse ignore_dB= argument.");
 473         goto fail;
 474     }
 475     u->ignore_dB = ignore_dB;
 476
 477     if (!(u->udev = udev_new())) {
 478         pa_log("Failed to initialize udev library.");
 479         goto fail;
 480     }
 481
 482     if (setup_inotify(u) < 0)
 483         goto fail;
 484
 485     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 486         pa_log("Failed to initialize monitor.");
 487         goto fail;
 488     }
 489
 490     errno = 0;
 491     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 492         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 493         if (errno == EPERM)
 494             pa_log_info("Most likely your kernel is simply too old and "
 495                         "allows only priviliged processes to listen to device events. "
 496                         "Please upgrade your kernel to at least 2.6.30.");
 497         goto fail;
 498     }
 499
 500     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 501         pa_log("Failed to get udev monitor fd.");
 502         goto fail;
 503     }
 504
 505     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 506
 507     if (!(enumerate = udev_enumerate_new(u->udev))) {
 508         pa_log("Failed to initialize udev enumerator.");
 509         goto fail;
 510     }
 511
 512     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 513         pa_log("Failed to match to subsystem.");
 514         goto fail;
 515     }
 516
 517     if (udev_enumerate_scan_devices(enumerate) < 0) {
 518         pa_log("Failed to scan for devices.");
 519         goto fail;
 520     }
 521
 522     first = udev_enumerate_get_list_entry(enumerate);
 523     udev_list_entry_foreach(item, first)
 524         process_path(u, udev_list_entry_get_name(item));
 525
 526     udev_enumerate_unref(enumerate);
 527
 528     pa_log_info("Found %u cards.", pa_hashmap_size(u->devices));
 529
 530     pa_modargs_free(ma);
 531
 532     return 0;
 533
 534 fail:
 535
 536     if (enumerate)
 537         udev_enumerate_unref(enumerate);
 538
 539     if (ma)
 540         pa_modargs_free(ma);
 541
 542     pa__done(m);
 543
 544     return -1;
 545 }
 546
 547 void pa__done(pa_module *m) {
 548     struct userdata *u;
 549
 550     pa_assert(m);
 551
 552     if (!(u = m->userdata))
 553         return;
 554
 555     if (u->udev_io)
 556         m->core->mainloop->io_free(u->udev_io);
 557
 558     if (u->monitor)
 559         udev_monitor_unref(u->monitor);
 560
 561     if (u->udev)
 562         udev_unref(u->udev);
 563
 564     if (u->inotify_io)
 565         m->core->mainloop->io_free(u->inotify_io);
 566
 567     if (u->inotify_fd >= 0)
 568         pa_close(u->inotify_fd);
 569
 570     if (u->devices) {
 571         struct device *d;
 572
 573         while ((d = pa_hashmap_steal_first(u->devices)))
 574             device_free(d);
 575
 576         pa_hashmap_free(u->devices, NULL, NULL);
 577     }
 578
 579     pa_xfree(u);
 580 }