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
  43 struct device {
  44     char *path;
  45     pa_bool_t accessible;
  46     char *card_name;
  47     uint32_t module;
  48 };
  49
  50 struct userdata {
  51     pa_core *core;
  52     pa_hashmap *devices;
  53     pa_bool_t use_tsched;
  54
  55     struct udev* udev;
  56     struct udev_monitor *monitor;
  57     pa_io_event *udev_io;
  58
  59     int inotify_fd;
  60     pa_io_event *inotify_io;
  61 };
  62
  63 static const char* const valid_modargs[] = {
  64     "tsched",
  65     NULL
  66 };
  67
  68 static int setup_inotify(struct userdata *u);
  69
  70 static void device_free(struct device *d) {
  71     pa_assert(d);
  72
  73     pa_xfree(d->path);
  74     pa_xfree(d->card_name);
  75     pa_xfree(d);
  76 }
  77
  78 static const char *path_get_card_id(const char *path) {
  79     const char *e;
  80
  81     if (!path)
  82         return NULL;
  83
  84     if (!(e = strrchr(path, '/')))
  85         return NULL;
  86
  87     if (!pa_startswith(e, "/card"))
  88         return NULL;
  89
  90     return e + 5;
  91 }
  92
  93 static void verify_access(struct userdata *u, struct device *d) {
  94     char *cd;
  95     pa_card *card;
  96
  97     pa_assert(u);
  98     pa_assert(d);
  99
 100     if (!(card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 101         return;
 102
 103     cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
 104     d->accessible = access(cd, W_OK) >= 0;
 105     pa_log_info("%s is accessible: %s", cd, pa_yes_no(d->accessible));
 106     pa_xfree(cd);
 107
 108     pa_card_suspend(card, !d->accessible, PA_SUSPEND_SESSION);
 109 }
 110
 111 static void card_changed(struct userdata *u, struct udev_device *dev) {
 112     struct device *d;
 113     const char *path;
 114     const char *t;
 115     char *card_name, *args;
 116     pa_module *m;
 117     char *n;
 118
 119     pa_assert(u);
 120     pa_assert(dev);
 121
 122     /* Maybe /dev/snd is now available? */
 123     setup_inotify(u);
 124
 125     path = udev_device_get_devpath(dev);
 126
 127     if ((d = pa_hashmap_get(u->devices, path))) {
 128         verify_access(u, d);
 129         return;
 130     }
 131
 132     if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
 133         if (!(t = udev_device_get_property_value(dev, "ID_ID")))
 134             if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
 135                 t = path_get_card_id(path);
 136
 137     n = pa_namereg_make_valid_name(t);
 138
 139     card_name = pa_sprintf_malloc("alsa_card.%s", n);
 140     args = pa_sprintf_malloc("device_id=\"%s\" "
 141                              "name=\"%s\" "
 142                              "card_name=\"%s\" "
 143                              "tsched=%i "
 144                              "card_properties=\"module-udev-detect.discovered=1\"",
 145                              path_get_card_id(path),
 146                              n,
 147                              card_name,
 148                              (int) u->use_tsched);
 149
 150     pa_log_debug("Loading module-alsa-card with arguments '%s'", args);
 151     m = pa_module_load(u->core, "module-alsa-card", args);
 152     pa_xfree(args);
 153
 154     if (m) {
 155         pa_log_info("Card %s (%s) added.", path, n);
 156
 157         d = pa_xnew(struct device, 1);
 158         d->path = pa_xstrdup(path);
 159         d->card_name = card_name;
 160         d->module = m->index;
 161         d->accessible = TRUE;
 162
 163         pa_hashmap_put(u->devices, d->path, d);
 164     } else
 165         pa_xfree(card_name);
 166
 167     pa_xfree(n);
 168 }
 169
 170 static void remove_card(struct userdata *u, struct udev_device *dev) {
 171     struct device *d;
 172
 173     pa_assert(u);
 174     pa_assert(dev);
 175
 176     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 177         return;
 178
 179     pa_log_info("Card %s removed.", d->path);
 180     pa_module_unload_request_by_index(u->core, d->module, TRUE);
 181     device_free(d);
 182 }
 183
 184 static void process_device(struct userdata *u, struct udev_device *dev) {
 185     const char *action, *ff;
 186
 187     pa_assert(u);
 188     pa_assert(dev);
 189
 190     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 191         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 192         return;
 193     }
 194
 195     if ((ff = udev_device_get_property_value(dev, "SOUND_FORM_FACTOR")) &&
 196         pa_streq(ff, "modem")) {
 197         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 198         return;
 199     }
 200
 201     action = udev_device_get_action(dev);
 202
 203     if (action && pa_streq(action, "remove"))
 204         remove_card(u, dev);
 205     else if ((!action || pa_streq(action, "change")) &&
 206              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 207         card_changed(u, dev);
 208
 209     /* For an explanation why we don't look for 'add' events here
 210      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 211 }
 212
 213 static void process_path(struct userdata *u, const char *path) {
 214     struct udev_device *dev;
 215
 216     if (!path_get_card_id(path))
 217         return;
 218
 219     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 220         pa_log("Failed to get udev device object from udev.");
 221         return;
 222     }
 223
 224     process_device(u, dev);
 225     udev_device_unref(dev);
 226 }
 227
 228 static void monitor_cb(
 229         pa_mainloop_api*a,
 230         pa_io_event* e,
 231         int fd,
 232         pa_io_event_flags_t events,
 233         void *userdata) {
 234
 235     struct userdata *u = userdata;
 236     struct udev_device *dev;
 237
 238     pa_assert(a);
 239
 240     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 241         pa_log("Failed to get udev device object from monitor.");
 242         goto fail;
 243     }
 244
 245     if (!path_get_card_id(udev_device_get_devpath(dev)))
 246         return;
 247
 248     process_device(u, dev);
 249     udev_device_unref(dev);
 250     return;
 251
 252 fail:
 253     a->io_free(u->udev_io);
 254     u->udev_io = NULL;
 255 }
 256
 257 static void inotify_cb(
 258         pa_mainloop_api*a,
 259         pa_io_event* e,
 260         int fd,
 261         pa_io_event_flags_t events,
 262         void *userdata) {
 263
 264     struct {
 265         struct inotify_event e;
 266         char name[NAME_MAX];
 267     } buf;
 268     struct userdata *u = userdata;
 269     static int type = 0;
 270     pa_bool_t verify = FALSE, deleted = FALSE;
 271
 272     for (;;) {
 273         ssize_t r;
 274
 275         pa_zero(buf);
 276         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 277
 278             if (r < 0 && errno == EAGAIN)
 279                 break;
 280
 281             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 282             goto fail;
 283         }
 284
 285         if ((buf.e.mask & IN_CLOSE_WRITE) && pa_startswith(buf.e.name, "pcmC"))
 286             verify = TRUE;
 287
 288         if ((buf.e.mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 289             deleted = TRUE;
 290     }
 291
 292     if (verify) {
 293         struct device *d;
 294         void *state;
 295
 296         pa_log_debug("Verifying access.");
 297
 298         PA_HASHMAP_FOREACH(d, u->devices, state)
 299             verify_access(u, d);
 300     }
 301
 302     if (!deleted)
 303         return;
 304
 305 fail:
 306     if (u->inotify_io) {
 307         a->io_free(u->inotify_io);
 308         u->inotify_io = NULL;
 309     }
 310
 311     if (u->inotify_fd >= 0) {
 312         pa_close(u->inotify_fd);
 313         u->inotify_fd = -1;
 314     }
 315 }
 316
 317 static int setup_inotify(struct userdata *u) {
 318     char *dev_snd;
 319     int r;
 320
 321     if (u->inotify_fd >= 0)
 322         return 0;
 323
 324     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 325         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 326         return -1;
 327     }
 328
 329     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 330     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 331     pa_xfree(dev_snd);
 332
 333     if (r < 0) {
 334         int saved_errno = errno;
 335
 336         pa_close(u->inotify_fd);
 337         u->inotify_fd = -1;
 338
 339         if (saved_errno == ENOENT) {
 340             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 341             return 0;
 342         }
 343
 344         if (saved_errno == ENOSPC) {
 345             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 346                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 347                    "directory trees which is something the current inotify is certainly not useful for. "
 348                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 349             return 0;
 350         }
 351
 352         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 353         return -1;
 354     }
 355
 356     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 357
 358     return 0;
 359 }
 360
 361 int pa__init(pa_module *m) {
 362     struct userdata *u = NULL;
 363     pa_modargs *ma;
 364     struct udev_enumerate *enumerate = NULL;
 365     struct udev_list_entry *item = NULL, *first = NULL;
 366     int fd;
 367
 368     pa_assert(m);
 369
 370     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 371         pa_log("Failed to parse module arguments");
 372         goto fail;
 373     }
 374
 375     m->userdata = u = pa_xnew0(struct userdata, 1);
 376     u->core = m->core;
 377     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 378     u->use_tsched = TRUE;
 379     u->inotify_fd = -1;
 380
 381     if (pa_modargs_get_value_boolean(ma, "tsched", &u->use_tsched) < 0) {
 382         pa_log("Failed to parse tsched argument.");
 383         goto fail;
 384     }
 385
 386     if (!(u->udev = udev_new())) {
 387         pa_log("Failed to initialize udev library.");
 388         goto fail;
 389     }
 390
 391     if (setup_inotify(u) < 0)
 392         goto fail;
 393
 394     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 395         pa_log("Failed to initialize monitor.");
 396         goto fail;
 397     }
 398
 399     errno = 0;
 400     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 401         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 402         if (errno == EPERM)
 403             pa_log_info("Most likely your kernel is simply too old and "
 404                         "allows only priviliged processes to listen to device events. "
 405                         "Please upgrade your kernel to at least 2.6.30.");
 406         goto fail;
 407     }
 408
 409     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 410         pa_log("Failed to get udev monitor fd.");
 411         goto fail;
 412     }
 413
 414     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 415
 416     if (!(enumerate = udev_enumerate_new(u->udev))) {
 417         pa_log("Failed to initialize udev enumerator.");
 418         goto fail;
 419     }
 420
 421     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 422         pa_log("Failed to match to subsystem.");
 423         goto fail;
 424     }
 425
 426     if (udev_enumerate_scan_devices(enumerate) < 0) {
 427         pa_log("Failed to scan for devices.");
 428         goto fail;
 429     }
 430
 431     first = udev_enumerate_get_list_entry(enumerate);
 432     udev_list_entry_foreach(item, first)
 433         process_path(u, udev_list_entry_get_name(item));
 434
 435     udev_enumerate_unref(enumerate);
 436
 437     pa_log_info("Loaded %u modules.", pa_hashmap_size(u->devices));
 438
 439     pa_modargs_free(ma);
 440
 441     return 0;
 442
 443 fail:
 444
 445     if (enumerate)
 446         udev_enumerate_unref(enumerate);
 447
 448     if (ma)
 449         pa_modargs_free(ma);
 450
 451     pa__done(m);
 452
 453     return -1;
 454 }
 455
 456 void pa__done(pa_module *m) {
 457     struct userdata *u;
 458
 459     pa_assert(m);
 460
 461     if (!(u = m->userdata))
 462         return;
 463
 464     if (u->udev_io)
 465         m->core->mainloop->io_free(u->udev_io);
 466
 467     if (u->monitor)
 468         udev_monitor_unref(u->monitor);
 469
 470     if (u->udev)
 471         udev_unref(u->udev);
 472
 473     if (u->inotify_io)
 474         m->core->mainloop->io_free(u->inotify_io);
 475
 476     if (u->inotify_fd >= 0)
 477         pa_close(u->inotify_fd);
 478
 479     if (u->devices) {
 480         struct device *d;
 481
 482         while ((d = pa_hashmap_steal_first(u->devices)))
 483             device_free(d);
 484
 485         pa_hashmap_free(u->devices, NULL, NULL);
 486     }
 487
 488     pa_xfree(u);
 489 }