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;
  49     char *card_name;
  50     char *args;
  51     uint32_t module;
  52 };
  53
  54 struct userdata {
  55     pa_core *core;
  56     pa_hashmap *devices;
  57
  58     pa_bool_t use_tsched:1;
  59     pa_bool_t ignore_dB:1;
  60
  61     struct udev* udev;
  62     struct udev_monitor *monitor;
  63     pa_io_event *udev_io;
  64
  65     int inotify_fd;
  66     pa_io_event *inotify_io;
  67 };
  68
  69 static const char* const valid_modargs[] = {
  70     "tsched",
  71     "ignore_dB",
  72     NULL
  73 };
  74
  75 static int setup_inotify(struct userdata *u);
  76
  77 static void device_free(struct device *d) {
  78     pa_assert(d);
  79
  80     pa_xfree(d->path);
  81     pa_xfree(d->card_name);
  82     pa_xfree(d->args);
  83     pa_xfree(d);
  84 }
  85
  86 static const char *path_get_card_id(const char *path) {
  87     const char *e;
  88
  89     if (!path)
  90         return NULL;
  91
  92     if (!(e = strrchr(path, '/')))
  93         return NULL;
  94
  95     if (!pa_startswith(e, "/card"))
  96         return NULL;
  97
  98     return e + 5;
  99 }
 100
 101 static void verify_access(struct userdata *u, struct device *d) {
 102     char *cd;
 103     pa_card *card;
 104
 105     pa_assert(u);
 106     pa_assert(d);
 107
 108     cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
 109     d->accessible = access(cd, R_OK|W_OK) >= 0;
 110     pa_xfree(cd);
 111
 112     pa_log_info("%s is accessible: %s", cd, pa_yes_no(d->accessible));
 113
 114     if (d->module == PA_INVALID_INDEX) {
 115
 116         /* If we not loaded, try to load */
 117
 118         if (d->accessible) {
 119             pa_module *m;
 120
 121             pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
 122             m = pa_module_load(u->core, "module-alsa-card", d->args);
 123
 124             if (m) {
 125                 d->module = m->index;
 126                 pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
 127             } else
 128                 pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
 129         }
 130
 131     } else {
 132
 133         /* If we are already loaded update suspend status with
 134          * accessible boolean */
 135
 136         if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 137             pa_card_suspend(card, !d->accessible, PA_SUSPEND_SESSION);
 138     }
 139 }
 140
 141 static void card_changed(struct userdata *u, struct udev_device *dev) {
 142     struct device *d;
 143     const char *path;
 144     const char *t;
 145     pa_module *m;
 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_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
 187     m = pa_module_load(u->core, "module-alsa-card", d->args);
 188
 189     if (m) {
 190         d->module = m->index;
 191         pa_log_info("Card %s (%s) added and module loaded.", path, d->card_name);
 192     } else
 193         pa_log_info("Card %s (%s) added but failed to load module.", path, d->card_name);
 194
 195     pa_hashmap_put(u->devices, d->path, d);
 196 }
 197
 198 static void remove_card(struct userdata *u, struct udev_device *dev) {
 199     struct device *d;
 200
 201     pa_assert(u);
 202     pa_assert(dev);
 203
 204     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 205         return;
 206
 207     pa_log_info("Card %s removed.", d->path);
 208
 209     if (d->module != PA_INVALID_INDEX)
 210         pa_module_unload_request_by_index(u->core, d->module, TRUE);
 211
 212     device_free(d);
 213 }
 214
 215 static void process_device(struct userdata *u, struct udev_device *dev) {
 216     const char *action, *ff;
 217
 218     pa_assert(u);
 219     pa_assert(dev);
 220
 221     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 222         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 223         return;
 224     }
 225
 226     if ((ff = udev_device_get_property_value(dev, "SOUND_FORM_FACTOR")) &&
 227         pa_streq(ff, "modem")) {
 228         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 229         return;
 230     }
 231
 232     action = udev_device_get_action(dev);
 233
 234     if (action && pa_streq(action, "remove"))
 235         remove_card(u, dev);
 236     else if ((!action || pa_streq(action, "change")) &&
 237              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 238         card_changed(u, dev);
 239
 240     /* For an explanation why we don't look for 'add' events here
 241      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 242 }
 243
 244 static void process_path(struct userdata *u, const char *path) {
 245     struct udev_device *dev;
 246
 247     if (!path_get_card_id(path))
 248         return;
 249
 250     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 251         pa_log("Failed to get udev device object from udev.");
 252         return;
 253     }
 254
 255     process_device(u, dev);
 256     udev_device_unref(dev);
 257 }
 258
 259 static void monitor_cb(
 260         pa_mainloop_api*a,
 261         pa_io_event* e,
 262         int fd,
 263         pa_io_event_flags_t events,
 264         void *userdata) {
 265
 266     struct userdata *u = userdata;
 267     struct udev_device *dev;
 268
 269     pa_assert(a);
 270
 271     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 272         pa_log("Failed to get udev device object from monitor.");
 273         goto fail;
 274     }
 275
 276     if (!path_get_card_id(udev_device_get_devpath(dev)))
 277         return;
 278
 279     process_device(u, dev);
 280     udev_device_unref(dev);
 281     return;
 282
 283 fail:
 284     a->io_free(u->udev_io);
 285     u->udev_io = NULL;
 286 }
 287
 288 static void inotify_cb(
 289         pa_mainloop_api*a,
 290         pa_io_event* e,
 291         int fd,
 292         pa_io_event_flags_t events,
 293         void *userdata) {
 294
 295     struct {
 296         struct inotify_event e;
 297         char name[NAME_MAX];
 298     } buf;
 299     struct userdata *u = userdata;
 300     static int type = 0;
 301     pa_bool_t verify = FALSE, deleted = FALSE;
 302
 303     for (;;) {
 304         ssize_t r;
 305
 306         pa_zero(buf);
 307         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 308
 309             if (r < 0 && errno == EAGAIN)
 310                 break;
 311
 312             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 313             goto fail;
 314         }
 315
 316         if ((buf.e.mask & IN_CLOSE_WRITE) && pa_startswith(buf.e.name, "pcmC"))
 317             verify = TRUE;
 318
 319         if ((buf.e.mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 320             deleted = TRUE;
 321     }
 322
 323     if (verify) {
 324         struct device *d;
 325         void *state;
 326
 327         pa_log_debug("Verifying access.");
 328
 329         PA_HASHMAP_FOREACH(d, u->devices, state)
 330             verify_access(u, d);
 331     }
 332
 333     if (!deleted)
 334         return;
 335
 336 fail:
 337     if (u->inotify_io) {
 338         a->io_free(u->inotify_io);
 339         u->inotify_io = NULL;
 340     }
 341
 342     if (u->inotify_fd >= 0) {
 343         pa_close(u->inotify_fd);
 344         u->inotify_fd = -1;
 345     }
 346 }
 347
 348 static int setup_inotify(struct userdata *u) {
 349     char *dev_snd;
 350     int r;
 351
 352     if (u->inotify_fd >= 0)
 353         return 0;
 354
 355     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 356         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 357         return -1;
 358     }
 359
 360     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 361     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 362     pa_xfree(dev_snd);
 363
 364     if (r < 0) {
 365         int saved_errno = errno;
 366
 367         pa_close(u->inotify_fd);
 368         u->inotify_fd = -1;
 369
 370         if (saved_errno == ENOENT) {
 371             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 372             return 0;
 373         }
 374
 375         if (saved_errno == ENOSPC) {
 376             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 377                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 378                    "directory trees which is something the current inotify is certainly not useful for. "
 379                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 380             return 0;
 381         }
 382
 383         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 384         return -1;
 385     }
 386
 387     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 388
 389     return 0;
 390 }
 391
 392 int pa__init(pa_module *m) {
 393     struct userdata *u = NULL;
 394     pa_modargs *ma;
 395     struct udev_enumerate *enumerate = NULL;
 396     struct udev_list_entry *item = NULL, *first = NULL;
 397     int fd;
 398     pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
 399
 400     pa_assert(m);
 401
 402     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 403         pa_log("Failed to parse module arguments");
 404         goto fail;
 405     }
 406
 407     m->userdata = u = pa_xnew0(struct userdata, 1);
 408     u->core = m->core;
 409     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 410     u->inotify_fd = -1;
 411
 412     if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
 413         pa_log("Failed to parse tsched= argument.");
 414         goto fail;
 415     }
 416     u->use_tsched = use_tsched;
 417
 418     if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
 419         pa_log("Failed to parse ignore_dB= argument.");
 420         goto fail;
 421     }
 422     u->ignore_dB = ignore_dB;
 423
 424     if (!(u->udev = udev_new())) {
 425         pa_log("Failed to initialize udev library.");
 426         goto fail;
 427     }
 428
 429     if (setup_inotify(u) < 0)
 430         goto fail;
 431
 432     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 433         pa_log("Failed to initialize monitor.");
 434         goto fail;
 435     }
 436
 437     errno = 0;
 438     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 439         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 440         if (errno == EPERM)
 441             pa_log_info("Most likely your kernel is simply too old and "
 442                         "allows only priviliged processes to listen to device events. "
 443                         "Please upgrade your kernel to at least 2.6.30.");
 444         goto fail;
 445     }
 446
 447     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 448         pa_log("Failed to get udev monitor fd.");
 449         goto fail;
 450     }
 451
 452     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 453
 454     if (!(enumerate = udev_enumerate_new(u->udev))) {
 455         pa_log("Failed to initialize udev enumerator.");
 456         goto fail;
 457     }
 458
 459     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 460         pa_log("Failed to match to subsystem.");
 461         goto fail;
 462     }
 463
 464     if (udev_enumerate_scan_devices(enumerate) < 0) {
 465         pa_log("Failed to scan for devices.");
 466         goto fail;
 467     }
 468
 469     first = udev_enumerate_get_list_entry(enumerate);
 470     udev_list_entry_foreach(item, first)
 471         process_path(u, udev_list_entry_get_name(item));
 472
 473     udev_enumerate_unref(enumerate);
 474
 475     pa_log_info("Loaded %u modules.", pa_hashmap_size(u->devices));
 476
 477     pa_modargs_free(ma);
 478
 479     return 0;
 480
 481 fail:
 482
 483     if (enumerate)
 484         udev_enumerate_unref(enumerate);
 485
 486     if (ma)
 487         pa_modargs_free(ma);
 488
 489     pa__done(m);
 490
 491     return -1;
 492 }
 493
 494 void pa__done(pa_module *m) {
 495     struct userdata *u;
 496
 497     pa_assert(m);
 498
 499     if (!(u = m->userdata))
 500         return;
 501
 502     if (u->udev_io)
 503         m->core->mainloop->io_free(u->udev_io);
 504
 505     if (u->monitor)
 506         udev_monitor_unref(u->monitor);
 507
 508     if (u->udev)
 509         udev_unref(u->udev);
 510
 511     if (u->inotify_io)
 512         m->core->mainloop->io_free(u->inotify_io);
 513
 514     if (u->inotify_fd >= 0)
 515         pa_close(u->inotify_fd);
 516
 517     if (u->devices) {
 518         struct device *d;
 519
 520         while ((d = pa_hashmap_steal_first(u->devices)))
 521             device_free(d);
 522
 523         pa_hashmap_free(u->devices, NULL, NULL);
 524     }
 525
 526     pa_xfree(u);
 527 }