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 <dirent.h>
  29 #include <sys/inotify.h>
  30 #include <libudev.h>
  31
  32 #include <pulsecore/modargs.h>
  33 #include <pulsecore/core-error.h>
  34 #include <pulsecore/core-util.h>
  35 #include <pulsecore/namereg.h>
  36
  37 #include "module-udev-detect-symdef.h"
  38
  39 PA_MODULE_AUTHOR("Lennart Poettering");
  40 PA_MODULE_DESCRIPTION("Detect available audio hardware and load matching drivers");
  41 PA_MODULE_VERSION(PACKAGE_VERSION);
  42 PA_MODULE_LOAD_ONCE(TRUE);
  43 PA_MODULE_USAGE(
  44         "tsched=<enable system timer based scheduling mode?> "
  45         "ignore_dB=<ignore dB information from the device?>");
  46
  47 struct device {
  48     char *path;
  49     pa_bool_t need_verify;
  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 pa_bool_t is_card_busy(const char *id) {
 103     char *card_path = NULL, *pcm_path = NULL, *sub_status = NULL;
 104     DIR *card_dir = NULL, *pcm_dir = NULL;
 105     FILE *status_file = NULL;
 106     size_t len;
 107     struct dirent *space = NULL, *de;
 108     pa_bool_t busy = FALSE;
 109     int r;
 110
 111     pa_assert(id);
 112
 113     card_path = pa_sprintf_malloc("/proc/asound/card%s", id);
 114
 115     if (!(card_dir = opendir(card_path))) {
 116         pa_log_warn("Failed to open %s: %s", card_path, pa_cstrerror(errno));
 117         goto fail;
 118     }
 119
 120     len = offsetof(struct dirent, d_name) + fpathconf(dirfd(card_dir), _PC_NAME_MAX) + 1;
 121     space = pa_xmalloc(len);
 122
 123     for (;;) {
 124         de = NULL;
 125
 126         if ((r = readdir_r(card_dir, space, &de)) != 0) {
 127             pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
 128             goto fail;
 129         }
 130
 131         if (!de)
 132             break;
 133
 134         if (!pa_startswith(de->d_name, "pcm"))
 135             continue;
 136
 137         pa_xfree(pcm_path);
 138         pcm_path = pa_sprintf_malloc("%s/%s", card_path, de->d_name);
 139
 140         if (pcm_dir)
 141             closedir(pcm_dir);
 142
 143         if (!(pcm_dir = opendir(pcm_path))) {
 144             pa_log_warn("Failed to open %s: %s", pcm_path, pa_cstrerror(errno));
 145             continue;
 146         }
 147
 148         for (;;) {
 149             char line[32];
 150
 151             if ((r = readdir_r(pcm_dir, space, &de)) != 0) {
 152                 pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
 153                 goto fail;
 154             }
 155
 156             if (!de)
 157                 break;
 158
 159             if (!pa_startswith(de->d_name, "sub"))
 160                 continue;
 161
 162             pa_xfree(sub_status);
 163             sub_status = pa_sprintf_malloc("%s/%s/status", pcm_path, de->d_name);
 164
 165             if (status_file)
 166                 fclose(status_file);
 167
 168             if (!(status_file = fopen(sub_status, "r"))) {
 169                 pa_log_warn("Failed to open %s: %s", sub_status, pa_cstrerror(errno));
 170                 continue;
 171             }
 172
 173             if (!(fgets(line, sizeof(line)-1, status_file))) {
 174                 pa_log_warn("Failed to read from %s: %s", sub_status, pa_cstrerror(errno));
 175                 continue;
 176             }
 177
 178             if (!pa_streq(line, "closed\n")) {
 179                 busy = TRUE;
 180                 break;
 181             }
 182         }
 183     }
 184
 185 fail:
 186
 187     pa_xfree(card_path);
 188     pa_xfree(pcm_path);
 189     pa_xfree(sub_status);
 190     pa_xfree(space);
 191
 192     if (card_dir)
 193         closedir(card_dir);
 194
 195     if (pcm_dir)
 196         closedir(pcm_dir);
 197
 198     if (status_file)
 199         fclose(status_file);
 200
 201     return busy;
 202 }
 203
 204 static void verify_access(struct userdata *u, struct device *d) {
 205     char *cd;
 206     pa_card *card;
 207     pa_bool_t accessible;
 208
 209     pa_assert(u);
 210     pa_assert(d);
 211
 212     cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
 213     accessible = access(cd, R_OK|W_OK) >= 0;
 214     pa_log_debug("%s is accessible: %s", cd, pa_yes_no(accessible));
 215
 216     pa_xfree(cd);
 217
 218     if (d->module == PA_INVALID_INDEX) {
 219
 220         /* If we are not loaded, try to load */
 221
 222         if (accessible) {
 223             pa_module *m;
 224             pa_bool_t busy;
 225
 226             /* Check if any of the PCM devices that belong to this
 227              * card are currently busy. If they are, don't try to load
 228              * right now, to make sure the probing phase can
 229              * successfully complete. When the current user of the
 230              * device closes it we will get another notification via
 231              * inotify and can then recheck. */
 232
 233             busy = is_card_busy(path_get_card_id(d->path));
 234             pa_log_debug("%s is busy: %s", d->path, pa_yes_no(busy));
 235
 236             if (!busy) {
 237                 pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
 238                 m = pa_module_load(u->core, "module-alsa-card", d->args);
 239
 240                 if (m) {
 241                     d->module = m->index;
 242                     pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
 243                 } else
 244                     pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
 245             }
 246         }
 247
 248     } else {
 249
 250         /* If we are already loaded update suspend status with
 251          * accessible boolean */
 252
 253         if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 254             pa_card_suspend(card, !accessible, PA_SUSPEND_SESSION);
 255     }
 256 }
 257
 258 static void card_changed(struct userdata *u, struct udev_device *dev) {
 259     struct device *d;
 260     const char *path;
 261     const char *t;
 262     char *n;
 263
 264     pa_assert(u);
 265     pa_assert(dev);
 266
 267     /* Maybe /dev/snd is now available? */
 268     setup_inotify(u);
 269
 270     path = udev_device_get_devpath(dev);
 271
 272     if ((d = pa_hashmap_get(u->devices, path))) {
 273         verify_access(u, d);
 274         return;
 275     }
 276
 277     d = pa_xnew0(struct device, 1);
 278     d->path = pa_xstrdup(path);
 279     d->module = PA_INVALID_INDEX;
 280
 281     if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
 282         if (!(t = udev_device_get_property_value(dev, "ID_ID")))
 283             if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
 284                 t = path_get_card_id(path);
 285
 286     n = pa_namereg_make_valid_name(t);
 287     d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
 288     d->args = pa_sprintf_malloc("device_id=\"%s\" "
 289                                 "name=\"%s\" "
 290                                 "card_name=\"%s\" "
 291                                 "tsched=%s "
 292                                 "ignore_dB=%s "
 293                                 "card_properties=\"module-udev-detect.discovered=1\"",
 294                                 path_get_card_id(path),
 295                                 n,
 296                                 d->card_name,
 297                                 pa_yes_no(u->use_tsched),
 298                                 pa_yes_no(u->ignore_dB));
 299     pa_xfree(n);
 300
 301     pa_hashmap_put(u->devices, d->path, d);
 302
 303     verify_access(u, d);
 304 }
 305
 306 static void remove_card(struct userdata *u, struct udev_device *dev) {
 307     struct device *d;
 308
 309     pa_assert(u);
 310     pa_assert(dev);
 311
 312     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 313         return;
 314
 315     pa_log_info("Card %s removed.", d->path);
 316
 317     if (d->module != PA_INVALID_INDEX)
 318         pa_module_unload_request_by_index(u->core, d->module, TRUE);
 319
 320     device_free(d);
 321 }
 322
 323 static void process_device(struct userdata *u, struct udev_device *dev) {
 324     const char *action, *ff;
 325
 326     pa_assert(u);
 327     pa_assert(dev);
 328
 329     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 330         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 331         return;
 332     }
 333
 334     if ((ff = udev_device_get_property_value(dev, "SOUND_FORM_FACTOR")) &&
 335         pa_streq(ff, "modem")) {
 336         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 337         return;
 338     }
 339
 340     action = udev_device_get_action(dev);
 341
 342     if (action && pa_streq(action, "remove"))
 343         remove_card(u, dev);
 344     else if ((!action || pa_streq(action, "change")) &&
 345              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 346         card_changed(u, dev);
 347
 348     /* For an explanation why we don't look for 'add' events here
 349      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 350 }
 351
 352 static void process_path(struct userdata *u, const char *path) {
 353     struct udev_device *dev;
 354
 355     if (!path_get_card_id(path))
 356         return;
 357
 358     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 359         pa_log("Failed to get udev device object from udev.");
 360         return;
 361     }
 362
 363     process_device(u, dev);
 364     udev_device_unref(dev);
 365 }
 366
 367 static void monitor_cb(
 368         pa_mainloop_api*a,
 369         pa_io_event* e,
 370         int fd,
 371         pa_io_event_flags_t events,
 372         void *userdata) {
 373
 374     struct userdata *u = userdata;
 375     struct udev_device *dev;
 376
 377     pa_assert(a);
 378
 379     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 380         pa_log("Failed to get udev device object from monitor.");
 381         goto fail;
 382     }
 383
 384     if (!path_get_card_id(udev_device_get_devpath(dev)))
 385         return;
 386
 387     process_device(u, dev);
 388     udev_device_unref(dev);
 389     return;
 390
 391 fail:
 392     a->io_free(u->udev_io);
 393     u->udev_io = NULL;
 394 }
 395
 396 static pa_bool_t pcm_node_belongs_to_device(
 397         struct device *d,
 398         const char *node) {
 399
 400     char *cd;
 401     pa_bool_t b;
 402
 403     cd = pa_sprintf_malloc("pcmC%sD", path_get_card_id(d->path));
 404     b = pa_startswith(node, cd);
 405     pa_xfree(cd);
 406
 407     return b;
 408 }
 409
 410 static pa_bool_t control_node_belongs_to_device(
 411         struct device *d,
 412         const char *node) {
 413
 414     char *cd;
 415     pa_bool_t b;
 416
 417     cd = pa_sprintf_malloc("controlC%s", path_get_card_id(d->path));
 418     b = pa_streq(node, cd);
 419     pa_xfree(cd);
 420
 421     return b;
 422 }
 423
 424 static void inotify_cb(
 425         pa_mainloop_api*a,
 426         pa_io_event* e,
 427         int fd,
 428         pa_io_event_flags_t events,
 429         void *userdata) {
 430
 431     struct {
 432         struct inotify_event e;
 433         char name[NAME_MAX];
 434     } buf;
 435     struct userdata *u = userdata;
 436     static int type = 0;
 437     pa_bool_t deleted = FALSE;
 438     struct device *d;
 439     void *state;
 440
 441     for (;;) {
 442         ssize_t r;
 443         struct inotify_event *event;
 444
 445         pa_zero(buf);
 446         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 447
 448             if (r < 0 && errno == EAGAIN)
 449                 break;
 450
 451             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 452             goto fail;
 453         }
 454
 455         event = &buf.e;
 456         while (r > 0) {
 457             size_t len;
 458
 459             if ((size_t) r < sizeof(struct inotify_event)) {
 460                 pa_log("read() too short.");
 461                 goto fail;
 462             }
 463
 464             len = sizeof(struct inotify_event) + event->len;
 465
 466             if ((size_t) r < len) {
 467                 pa_log("Payload missing.");
 468                 goto fail;
 469             }
 470
 471             /* From udev we get the guarantee that the control
 472              * device's ACL is changed last. To avoid races when ACLs
 473              * are changed we hence watch only the control device */
 474             if (((event->mask & IN_ATTRIB) && pa_startswith(event->name, "controlC")))
 475                 PA_HASHMAP_FOREACH(d, u->devices, state)
 476                     if (control_node_belongs_to_device(d, event->name))
 477                         d->need_verify = TRUE;
 478
 479             /* ALSA doesn't really give us any guarantee on the closing
 480              * order, so let's simply hope */
 481             if (((event->mask & IN_CLOSE_WRITE) && pa_startswith(event->name, "pcmC")))
 482                 PA_HASHMAP_FOREACH(d, u->devices, state)
 483                     if (pcm_node_belongs_to_device(d, event->name))
 484                         d->need_verify = TRUE;
 485
 486             /* /dev/snd/ might have been removed */
 487             if ((event->mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 488                 deleted = TRUE;
 489
 490             event = (struct inotify_event*) ((uint8_t*) event + len);
 491             r -= len;
 492         }
 493     }
 494
 495     PA_HASHMAP_FOREACH(d, u->devices, state)
 496         if (d->need_verify) {
 497             d->need_verify = FALSE;
 498             verify_access(u, d);
 499         }
 500
 501     if (!deleted)
 502         return;
 503
 504 fail:
 505     if (u->inotify_io) {
 506         a->io_free(u->inotify_io);
 507         u->inotify_io = NULL;
 508     }
 509
 510     if (u->inotify_fd >= 0) {
 511         pa_close(u->inotify_fd);
 512         u->inotify_fd = -1;
 513     }
 514 }
 515
 516 static int setup_inotify(struct userdata *u) {
 517     char *dev_snd;
 518     int r;
 519
 520     if (u->inotify_fd >= 0)
 521         return 0;
 522
 523     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 524         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 525         return -1;
 526     }
 527
 528     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 529     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_ATTRIB|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 530     pa_xfree(dev_snd);
 531
 532     if (r < 0) {
 533         int saved_errno = errno;
 534
 535         pa_close(u->inotify_fd);
 536         u->inotify_fd = -1;
 537
 538         if (saved_errno == ENOENT) {
 539             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 540             return 0;
 541         }
 542
 543         if (saved_errno == ENOSPC) {
 544             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 545                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 546                    "directory trees which is something the current inotify is certainly not useful for. "
 547                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 548             return 0;
 549         }
 550
 551         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 552         return -1;
 553     }
 554
 555     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 556
 557     return 0;
 558 }
 559
 560 int pa__init(pa_module *m) {
 561     struct userdata *u = NULL;
 562     pa_modargs *ma;
 563     struct udev_enumerate *enumerate = NULL;
 564     struct udev_list_entry *item = NULL, *first = NULL;
 565     int fd;
 566     pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
 567
 568     pa_assert(m);
 569
 570     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 571         pa_log("Failed to parse module arguments");
 572         goto fail;
 573     }
 574
 575     m->userdata = u = pa_xnew0(struct userdata, 1);
 576     u->core = m->core;
 577     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 578     u->inotify_fd = -1;
 579
 580     if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
 581         pa_log("Failed to parse tsched= argument.");
 582         goto fail;
 583     }
 584     u->use_tsched = use_tsched;
 585
 586     if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
 587         pa_log("Failed to parse ignore_dB= argument.");
 588         goto fail;
 589     }
 590     u->ignore_dB = ignore_dB;
 591
 592     if (!(u->udev = udev_new())) {
 593         pa_log("Failed to initialize udev library.");
 594         goto fail;
 595     }
 596
 597     if (setup_inotify(u) < 0)
 598         goto fail;
 599
 600     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 601         pa_log("Failed to initialize monitor.");
 602         goto fail;
 603     }
 604
 605     errno = 0;
 606     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 607         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 608         if (errno == EPERM)
 609             pa_log_info("Most likely your kernel is simply too old and "
 610                         "allows only priviliged processes to listen to device events. "
 611                         "Please upgrade your kernel to at least 2.6.30.");
 612         goto fail;
 613     }
 614
 615     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 616         pa_log("Failed to get udev monitor fd.");
 617         goto fail;
 618     }
 619
 620     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 621
 622     if (!(enumerate = udev_enumerate_new(u->udev))) {
 623         pa_log("Failed to initialize udev enumerator.");
 624         goto fail;
 625     }
 626
 627     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 628         pa_log("Failed to match to subsystem.");
 629         goto fail;
 630     }
 631
 632     if (udev_enumerate_scan_devices(enumerate) < 0) {
 633         pa_log("Failed to scan for devices.");
 634         goto fail;
 635     }
 636
 637     first = udev_enumerate_get_list_entry(enumerate);
 638     udev_list_entry_foreach(item, first)
 639         process_path(u, udev_list_entry_get_name(item));
 640
 641     udev_enumerate_unref(enumerate);
 642
 643     pa_log_info("Found %u cards.", pa_hashmap_size(u->devices));
 644
 645     pa_modargs_free(ma);
 646
 647     return 0;
 648
 649 fail:
 650
 651     if (enumerate)
 652         udev_enumerate_unref(enumerate);
 653
 654     if (ma)
 655         pa_modargs_free(ma);
 656
 657     pa__done(m);
 658
 659     return -1;
 660 }
 661
 662 void pa__done(pa_module *m) {
 663     struct userdata *u;
 664
 665     pa_assert(m);
 666
 667     if (!(u = m->userdata))
 668         return;
 669
 670     if (u->udev_io)
 671         m->core->mainloop->io_free(u->udev_io);
 672
 673     if (u->monitor)
 674         udev_monitor_unref(u->monitor);
 675
 676     if (u->udev)
 677         udev_unref(u->udev);
 678
 679     if (u->inotify_io)
 680         m->core->mainloop->io_free(u->inotify_io);
 681
 682     if (u->inotify_fd >= 0)
 683         pa_close(u->inotify_fd);
 684
 685     if (u->devices) {
 686         struct device *d;
 687
 688         while ((d = pa_hashmap_steal_first(u->devices)))
 689             device_free(d);
 690
 691         pa_hashmap_free(u->devices, NULL, NULL);
 692     }
 693
 694     pa_xfree(u);
 695 }