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