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;
  49     char *card_name;
  50     uint32_t module;
  51 };
  52
  53 struct userdata {
  54     pa_core *core;
  55     pa_hashmap *devices;
  56
  57     pa_bool_t use_tsched:1;
  58     pa_bool_t ignore_dB:1;
  59
  60     struct udev* udev;
  61     struct udev_monitor *monitor;
  62     pa_io_event *udev_io;
  63
  64     int inotify_fd;
  65     pa_io_event *inotify_io;
  66 };
  67
  68 static const char* const valid_modargs[] = {
  69     "tsched",
  70     "ignore_dB",
  71     NULL
  72 };
  73
  74 static int setup_inotify(struct userdata *u);
  75
  76 static void device_free(struct device *d) {
  77     pa_assert(d);
  78
  79     pa_xfree(d->path);
  80     pa_xfree(d->card_name);
  81     pa_xfree(d);
  82 }
  83
  84 static const char *path_get_card_id(const char *path) {
  85     const char *e;
  86
  87     if (!path)
  88         return NULL;
  89
  90     if (!(e = strrchr(path, '/')))
  91         return NULL;
  92
  93     if (!pa_startswith(e, "/card"))
  94         return NULL;
  95
  96     return e + 5;
  97 }
  98
  99 static void verify_access(struct userdata *u, struct device *d) {
 100     char *cd;
 101     pa_card *card;
 102
 103     pa_assert(u);
 104     pa_assert(d);
 105
 106     if (!(card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 107         return;
 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, W_OK) >= 0;
 111     pa_log_info("%s is accessible: %s", cd, pa_yes_no(d->accessible));
 112     pa_xfree(cd);
 113
 114     pa_card_suspend(card, !d->accessible, PA_SUSPEND_SESSION);
 115 }
 116
 117 static void card_changed(struct userdata *u, struct udev_device *dev) {
 118     struct device *d;
 119     const char *path;
 120     const char *t;
 121     char *card_name, *args;
 122     pa_module *m;
 123     char *n;
 124
 125     pa_assert(u);
 126     pa_assert(dev);
 127
 128     /* Maybe /dev/snd is now available? */
 129     setup_inotify(u);
 130
 131     path = udev_device_get_devpath(dev);
 132
 133     if ((d = pa_hashmap_get(u->devices, path))) {
 134         verify_access(u, d);
 135         return;
 136     }
 137
 138     if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
 139         if (!(t = udev_device_get_property_value(dev, "ID_ID")))
 140             if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
 141                 t = path_get_card_id(path);
 142
 143     n = pa_namereg_make_valid_name(t);
 144
 145     card_name = pa_sprintf_malloc("alsa_card.%s", n);
 146     args = pa_sprintf_malloc("device_id=\"%s\" "
 147                              "name=\"%s\" "
 148                              "card_name=\"%s\" "
 149                              "tsched=%s "
 150                              "ignore_dB=%s "
 151                              "card_properties=\"module-udev-detect.discovered=1\"",
 152                              path_get_card_id(path),
 153                              n,
 154                              card_name,
 155                              pa_yes_no(u->use_tsched),
 156                              pa_yes_no(u->ignore_dB));
 157
 158     pa_log_debug("Loading module-alsa-card with arguments '%s'", args);
 159     m = pa_module_load(u->core, "module-alsa-card", args);
 160     pa_xfree(args);
 161
 162     if (m) {
 163         pa_log_info("Card %s (%s) added.", path, n);
 164
 165         d = pa_xnew(struct device, 1);
 166         d->path = pa_xstrdup(path);
 167         d->card_name = card_name;
 168         d->module = m->index;
 169         d->accessible = TRUE;
 170
 171         pa_hashmap_put(u->devices, d->path, d);
 172     } else
 173         pa_xfree(card_name);
 174
 175     pa_xfree(n);
 176 }
 177
 178 static void remove_card(struct userdata *u, struct udev_device *dev) {
 179     struct device *d;
 180
 181     pa_assert(u);
 182     pa_assert(dev);
 183
 184     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 185         return;
 186
 187     pa_log_info("Card %s removed.", d->path);
 188     pa_module_unload_request_by_index(u->core, d->module, TRUE);
 189     device_free(d);
 190 }
 191
 192 static void process_device(struct userdata *u, struct udev_device *dev) {
 193     const char *action, *ff;
 194
 195     pa_assert(u);
 196     pa_assert(dev);
 197
 198     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 199         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 200         return;
 201     }
 202
 203     if ((ff = udev_device_get_property_value(dev, "SOUND_FORM_FACTOR")) &&
 204         pa_streq(ff, "modem")) {
 205         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 206         return;
 207     }
 208
 209     action = udev_device_get_action(dev);
 210
 211     if (action && pa_streq(action, "remove"))
 212         remove_card(u, dev);
 213     else if ((!action || pa_streq(action, "change")) &&
 214              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 215         card_changed(u, dev);
 216
 217     /* For an explanation why we don't look for 'add' events here
 218      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 219 }
 220
 221 static void process_path(struct userdata *u, const char *path) {
 222     struct udev_device *dev;
 223
 224     if (!path_get_card_id(path))
 225         return;
 226
 227     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 228         pa_log("Failed to get udev device object from udev.");
 229         return;
 230     }
 231
 232     process_device(u, dev);
 233     udev_device_unref(dev);
 234 }
 235
 236 static void monitor_cb(
 237         pa_mainloop_api*a,
 238         pa_io_event* e,
 239         int fd,
 240         pa_io_event_flags_t events,
 241         void *userdata) {
 242
 243     struct userdata *u = userdata;
 244     struct udev_device *dev;
 245
 246     pa_assert(a);
 247
 248     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 249         pa_log("Failed to get udev device object from monitor.");
 250         goto fail;
 251     }
 252
 253     if (!path_get_card_id(udev_device_get_devpath(dev)))
 254         return;
 255
 256     process_device(u, dev);
 257     udev_device_unref(dev);
 258     return;
 259
 260 fail:
 261     a->io_free(u->udev_io);
 262     u->udev_io = NULL;
 263 }
 264
 265 static void inotify_cb(
 266         pa_mainloop_api*a,
 267         pa_io_event* e,
 268         int fd,
 269         pa_io_event_flags_t events,
 270         void *userdata) {
 271
 272     struct {
 273         struct inotify_event e;
 274         char name[NAME_MAX];
 275     } buf;
 276     struct userdata *u = userdata;
 277     static int type = 0;
 278     pa_bool_t verify = FALSE, deleted = FALSE;
 279
 280     for (;;) {
 281         ssize_t r;
 282
 283         pa_zero(buf);
 284         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 285
 286             if (r < 0 && errno == EAGAIN)
 287                 break;
 288
 289             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 290             goto fail;
 291         }
 292
 293         if ((buf.e.mask & IN_CLOSE_WRITE) && pa_startswith(buf.e.name, "pcmC"))
 294             verify = TRUE;
 295
 296         if ((buf.e.mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 297             deleted = TRUE;
 298     }
 299
 300     if (verify) {
 301         struct device *d;
 302         void *state;
 303
 304         pa_log_debug("Verifying access.");
 305
 306         PA_HASHMAP_FOREACH(d, u->devices, state)
 307             verify_access(u, d);
 308     }
 309
 310     if (!deleted)
 311         return;
 312
 313 fail:
 314     if (u->inotify_io) {
 315         a->io_free(u->inotify_io);
 316         u->inotify_io = NULL;
 317     }
 318
 319     if (u->inotify_fd >= 0) {
 320         pa_close(u->inotify_fd);
 321         u->inotify_fd = -1;
 322     }
 323 }
 324
 325 static int setup_inotify(struct userdata *u) {
 326     char *dev_snd;
 327     int r;
 328
 329     if (u->inotify_fd >= 0)
 330         return 0;
 331
 332     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 333         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 334         return -1;
 335     }
 336
 337     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 338     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 339     pa_xfree(dev_snd);
 340
 341     if (r < 0) {
 342         int saved_errno = errno;
 343
 344         pa_close(u->inotify_fd);
 345         u->inotify_fd = -1;
 346
 347         if (saved_errno == ENOENT) {
 348             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 349             return 0;
 350         }
 351
 352         if (saved_errno == ENOSPC) {
 353             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 354                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 355                    "directory trees which is something the current inotify is certainly not useful for. "
 356                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 357             return 0;
 358         }
 359
 360         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 361         return -1;
 362     }
 363
 364     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 365
 366     return 0;
 367 }
 368
 369 int pa__init(pa_module *m) {
 370     struct userdata *u = NULL;
 371     pa_modargs *ma;
 372     struct udev_enumerate *enumerate = NULL;
 373     struct udev_list_entry *item = NULL, *first = NULL;
 374     int fd;
 375     pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
 376
 377     pa_assert(m);
 378
 379     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 380         pa_log("Failed to parse module arguments");
 381         goto fail;
 382     }
 383
 384     m->userdata = u = pa_xnew0(struct userdata, 1);
 385     u->core = m->core;
 386     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 387     u->inotify_fd = -1;
 388
 389     if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
 390         pa_log("Failed to parse tsched= argument.");
 391         goto fail;
 392     }
 393     u->use_tsched = use_tsched;
 394
 395     if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
 396         pa_log("Failed to parse ignore_dB= argument.");
 397         goto fail;
 398     }
 399     u->ignore_dB = ignore_dB;
 400
 401     if (!(u->udev = udev_new())) {
 402         pa_log("Failed to initialize udev library.");
 403         goto fail;
 404     }
 405
 406     if (setup_inotify(u) < 0)
 407         goto fail;
 408
 409     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 410         pa_log("Failed to initialize monitor.");
 411         goto fail;
 412     }
 413
 414     errno = 0;
 415     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 416         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 417         if (errno == EPERM)
 418             pa_log_info("Most likely your kernel is simply too old and "
 419                         "allows only priviliged processes to listen to device events. "
 420                         "Please upgrade your kernel to at least 2.6.30.");
 421         goto fail;
 422     }
 423
 424     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 425         pa_log("Failed to get udev monitor fd.");
 426         goto fail;
 427     }
 428
 429     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 430
 431     if (!(enumerate = udev_enumerate_new(u->udev))) {
 432         pa_log("Failed to initialize udev enumerator.");
 433         goto fail;
 434     }
 435
 436     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 437         pa_log("Failed to match to subsystem.");
 438         goto fail;
 439     }
 440
 441     if (udev_enumerate_scan_devices(enumerate) < 0) {
 442         pa_log("Failed to scan for devices.");
 443         goto fail;
 444     }
 445
 446     first = udev_enumerate_get_list_entry(enumerate);
 447     udev_list_entry_foreach(item, first)
 448         process_path(u, udev_list_entry_get_name(item));
 449
 450     udev_enumerate_unref(enumerate);
 451
 452     pa_log_info("Loaded %u modules.", pa_hashmap_size(u->devices));
 453
 454     pa_modargs_free(ma);
 455
 456     return 0;
 457
 458 fail:
 459
 460     if (enumerate)
 461         udev_enumerate_unref(enumerate);
 462
 463     if (ma)
 464         pa_modargs_free(ma);
 465
 466     pa__done(m);
 467
 468     return -1;
 469 }
 470
 471 void pa__done(pa_module *m) {
 472     struct userdata *u;
 473
 474     pa_assert(m);
 475
 476     if (!(u = m->userdata))
 477         return;
 478
 479     if (u->udev_io)
 480         m->core->mainloop->io_free(u->udev_io);
 481
 482     if (u->monitor)
 483         udev_monitor_unref(u->monitor);
 484
 485     if (u->udev)
 486         udev_unref(u->udev);
 487
 488     if (u->inotify_io)
 489         m->core->mainloop->io_free(u->inotify_io);
 490
 491     if (u->inotify_fd >= 0)
 492         pa_close(u->inotify_fd);
 493
 494     if (u->devices) {
 495         struct device *d;
 496
 497         while ((d = pa_hashmap_steal_first(u->devices)))
 498             device_free(d);
 499
 500         pa_hashmap_free(u->devices, NULL, NULL);
 501     }
 502
 503     pa_xfree(u);
 504 }