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pulseaudio/src/modules/module-udev-detect.c
Marc-Antoine Perennou 2e64edbd3e udev: Don't use deprecated udev_get_*_path() functions 
[These symbols were removed in libudev.so.1.0.0. Replace them with
hardcoded strings. -- heftig]

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
2012-07-03 17:18:39 +05:30

817 lines
23 KiB
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/***
This file is part of PulseAudio.
Copyright 2009 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with PulseAudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <limits.h>
#include <dirent.h>
#include <sys/inotify.h>
#include <libudev.h>
#include <pulse/timeval.h>
#include <pulsecore/modargs.h>
#include <pulsecore/core-error.h>
#include <pulsecore/core-util.h>
#include <pulsecore/namereg.h>
#include <pulsecore/ratelimit.h>
#include "module-udev-detect-symdef.h"
PA_MODULE_AUTHOR("Lennart Poettering");
PA_MODULE_DESCRIPTION("Detect available audio hardware and load matching drivers");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(TRUE);
PA_MODULE_USAGE(
"tsched=<enable system timer based scheduling mode?> "
"fixed_latency_range=<disable latency range changes on underrun?> "
"ignore_dB=<ignore dB information from the device?> "
"deferred_volume=<syncronize sw and hw volume changes in IO-thread?>");
struct device {
char *path;
pa_bool_t need_verify;
char *card_name;
char *args;
uint32_t module;
pa_ratelimit ratelimit;
};
struct userdata {
pa_core *core;
pa_hashmap *devices;
pa_bool_t use_tsched:1;
pa_bool_t fixed_latency_range:1;
pa_bool_t ignore_dB:1;
pa_bool_t deferred_volume:1;
struct udev* udev;
struct udev_monitor *monitor;
pa_io_event *udev_io;
int inotify_fd;
pa_io_event *inotify_io;
};
static const char* const valid_modargs[] = {
"tsched",
"fixed_latency_range",
"ignore_dB",
"deferred_volume",
NULL
};
static int setup_inotify(struct userdata *u);
static void device_free(struct device *d) {
pa_assert(d);
pa_xfree(d->path);
pa_xfree(d->card_name);
pa_xfree(d->args);
pa_xfree(d);
}
static const char *path_get_card_id(const char *path) {
const char *e;
if (!path)
return NULL;
if (!(e = strrchr(path, '/')))
return NULL;
if (!pa_startswith(e, "/card"))
return NULL;
return e + 5;
}
static char *card_get_sysattr(const char *card_idx, const char *name) {
struct udev *udev;
struct udev_device *card = NULL;
char *t, *r = NULL;
const char *v;
pa_assert(card_idx);
pa_assert(name);
if (!(udev = udev_new())) {
pa_log_error("Failed to allocate udev context.");
goto finish;
}
t = pa_sprintf_malloc("/sys/class/sound/card%s", card_idx);
card = udev_device_new_from_syspath(udev, t);
pa_xfree(t);
if (!card) {
pa_log_error("Failed to get card object.");
goto finish;
}
if ((v = udev_device_get_sysattr_value(card, name)) && *v)
r = pa_xstrdup(v);
finish:
if (card)
udev_device_unref(card);
if (udev)
udev_unref(udev);
return r;
}
static pa_bool_t pcm_is_modem(const char *card_idx, const char *pcm) {
char *sysfs_path, *pcm_class;
pa_bool_t is_modem;
pa_assert(card_idx);
pa_assert(pcm);
/* Check /sys/class/sound/card.../pcmC...../pcm_class. An HDA
* modem can be used simultaneously with generic
* playback/record. */
sysfs_path = pa_sprintf_malloc("pcmC%sD%s/pcm_class", card_idx, pcm);
pcm_class = card_get_sysattr(card_idx, sysfs_path);
is_modem = pcm_class && pa_streq(pcm_class, "modem");
pa_xfree(pcm_class);
pa_xfree(sysfs_path);
return is_modem;
}
static pa_bool_t is_card_busy(const char *id) {
char *card_path = NULL, *pcm_path = NULL, *sub_status = NULL;
DIR *card_dir = NULL, *pcm_dir = NULL;
FILE *status_file = NULL;
size_t len;
struct dirent *space = NULL, *de;
pa_bool_t busy = FALSE;
int r;
pa_assert(id);
/* This simply uses /proc/asound/card.../pcm.../sub.../status to
* check whether there is still a process using this audio device. */
card_path = pa_sprintf_malloc("/proc/asound/card%s", id);
if (!(card_dir = opendir(card_path))) {
pa_log_warn("Failed to open %s: %s", card_path, pa_cstrerror(errno));
goto fail;
}
len = offsetof(struct dirent, d_name) + fpathconf(dirfd(card_dir), _PC_NAME_MAX) + 1;
space = pa_xmalloc(len);
for (;;) {
de = NULL;
if ((r = readdir_r(card_dir, space, &de)) != 0) {
pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
goto fail;
}
if (!de)
break;
if (!pa_startswith(de->d_name, "pcm"))
continue;
if (pcm_is_modem(id, de->d_name + 3))
continue;
pa_xfree(pcm_path);
pcm_path = pa_sprintf_malloc("%s/%s", card_path, de->d_name);
if (pcm_dir)
closedir(pcm_dir);
if (!(pcm_dir = opendir(pcm_path))) {
pa_log_warn("Failed to open %s: %s", pcm_path, pa_cstrerror(errno));
continue;
}
for (;;) {
char line[32];
if ((r = readdir_r(pcm_dir, space, &de)) != 0) {
pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
goto fail;
}
if (!de)
break;
if (!pa_startswith(de->d_name, "sub"))
continue;
pa_xfree(sub_status);
sub_status = pa_sprintf_malloc("%s/%s/status", pcm_path, de->d_name);
if (status_file)
fclose(status_file);
if (!(status_file = pa_fopen_cloexec(sub_status, "r"))) {
pa_log_warn("Failed to open %s: %s", sub_status, pa_cstrerror(errno));
continue;
}
if (!(fgets(line, sizeof(line)-1, status_file))) {
pa_log_warn("Failed to read from %s: %s", sub_status, pa_cstrerror(errno));
continue;
}
if (!pa_streq(line, "closed\n")) {
busy = TRUE;
break;
}
}
}
fail:
pa_xfree(card_path);
pa_xfree(pcm_path);
pa_xfree(sub_status);
pa_xfree(space);
if (card_dir)
closedir(card_dir);
if (pcm_dir)
closedir(pcm_dir);
if (status_file)
fclose(status_file);
return busy;
}
static void verify_access(struct userdata *u, struct device *d) {
char *cd;
pa_card *card;
pa_bool_t accessible;
pa_assert(u);
pa_assert(d);
cd = pa_sprintf_malloc("/dev/snd/controlC%s", path_get_card_id(d->path));
accessible = access(cd, R_OK|W_OK) >= 0;
pa_log_debug("%s is accessible: %s", cd, pa_yes_no(accessible));
pa_xfree(cd);
if (d->module == PA_INVALID_INDEX) {
/* If we are not loaded, try to load */
if (accessible) {
pa_module *m;
pa_bool_t busy;
/* Check if any of the PCM devices that belong to this
* card are currently busy. If they are, don't try to load
* right now, to make sure the probing phase can
* successfully complete. When the current user of the
* device closes it we will get another notification via
* inotify and can then recheck. */
busy = is_card_busy(path_get_card_id(d->path));
pa_log_debug("%s is busy: %s", d->path, pa_yes_no(busy));
if (!busy) {
/* So, why do we rate limit here? It's certainly ugly,
* but there seems to be no other way. Problem is
* this: if we are unable to configure/probe an audio
* device after opening it we will close it again and
* the module initialization will fail. This will then
* cause an inotify event on the device node which
* will be forwarded to us. We then try to reopen the
* audio device again, practically entering a busy
* loop.
*
* A clean fix would be if we would be able to ignore
* our own inotify close events. However, inotify
* lacks such functionality. Also, during probing of
* the device we cannot really distinguish between
* other processes causing EBUSY or ourselves, which
* means we have no way to figure out if the probing
* during opening was canceled by a "try again"
* failure or a "fatal" failure. */
if (pa_ratelimit_test(&d->ratelimit, PA_LOG_DEBUG)) {
pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
m = pa_module_load(u->core, "module-alsa-card", d->args);
if (m) {
d->module = m->index;
pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
} else
pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
} else
pa_log_warn("Tried to configure %s (%s) more often than %u times in %llus",
d->path,
d->card_name,
d->ratelimit.burst,
(long long unsigned) (d->ratelimit.interval / PA_USEC_PER_SEC));
}
}
} else {
/* If we are already loaded update suspend status with
* accessible boolean */
if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
pa_card_suspend(card, !accessible, PA_SUSPEND_SESSION);
}
}
static void card_changed(struct userdata *u, struct udev_device *dev) {
struct device *d;
const char *path;
const char *t;
char *n;
pa_assert(u);
pa_assert(dev);
/* Maybe /dev/snd is now available? */
setup_inotify(u);
path = udev_device_get_devpath(dev);
if ((d = pa_hashmap_get(u->devices, path))) {
verify_access(u, d);
return;
}
d = pa_xnew0(struct device, 1);
d->path = pa_xstrdup(path);
d->module = PA_INVALID_INDEX;
PA_INIT_RATELIMIT(d->ratelimit, 10*PA_USEC_PER_SEC, 5);
if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
if (!(t = udev_device_get_property_value(dev, "ID_ID")))
if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
t = path_get_card_id(path);
n = pa_namereg_make_valid_name(t);
d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
d->args = pa_sprintf_malloc("device_id=\"%s\" "
"name=\"%s\" "
"card_name=\"%s\" "
"namereg_fail=false "
"tsched=%s "
"fixed_latency_range=%s "
"ignore_dB=%s "
"deferred_volume=%s "
"card_properties=\"module-udev-detect.discovered=1\"",
path_get_card_id(path),
n,
d->card_name,
pa_yes_no(u->use_tsched),
pa_yes_no(u->fixed_latency_range),
pa_yes_no(u->ignore_dB),
pa_yes_no(u->deferred_volume));
pa_xfree(n);
pa_hashmap_put(u->devices, d->path, d);
verify_access(u, d);
}
static void remove_card(struct userdata *u, struct udev_device *dev) {
struct device *d;
pa_assert(u);
pa_assert(dev);
if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
return;
pa_log_info("Card %s removed.", d->path);
if (d->module != PA_INVALID_INDEX)
pa_module_unload_request_by_index(u->core, d->module, TRUE);
device_free(d);
}
static void process_device(struct userdata *u, struct udev_device *dev) {
const char *action, *ff;
pa_assert(u);
pa_assert(dev);
if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
return;
}
if ((ff = udev_device_get_property_value(dev, "SOUND_CLASS")) &&
pa_streq(ff, "modem")) {
pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
return;
}
action = udev_device_get_action(dev);
if (action && pa_streq(action, "remove"))
remove_card(u, dev);
else if ((!action || pa_streq(action, "change")) && udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
card_changed(u, dev);
/* For an explanation why we don't look for 'add' events here
* have a look into /lib/udev/rules.d/78-sound-card.rules! */
}
static void process_path(struct userdata *u, const char *path) {
struct udev_device *dev;
if (!path_get_card_id(path))
return;
if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
pa_log("Failed to get udev device object from udev.");
return;
}
process_device(u, dev);
udev_device_unref(dev);
}
static void monitor_cb(
pa_mainloop_api*a,
pa_io_event* e,
int fd,
pa_io_event_flags_t events,
void *userdata) {
struct userdata *u = userdata;
struct udev_device *dev;
pa_assert(a);
if (!(dev = udev_monitor_receive_device(u->monitor))) {
pa_log("Failed to get udev device object from monitor.");
goto fail;
}
if (!path_get_card_id(udev_device_get_devpath(dev))) {
udev_device_unref(dev);
return;
}
process_device(u, dev);
udev_device_unref(dev);
return;
fail:
a->io_free(u->udev_io);
u->udev_io = NULL;
}
static pa_bool_t pcm_node_belongs_to_device(
struct device *d,
const char *node) {
char *cd;
pa_bool_t b;
cd = pa_sprintf_malloc("pcmC%sD", path_get_card_id(d->path));
b = pa_startswith(node, cd);
pa_xfree(cd);
return b;
}
static pa_bool_t control_node_belongs_to_device(
struct device *d,
const char *node) {
char *cd;
pa_bool_t b;
cd = pa_sprintf_malloc("controlC%s", path_get_card_id(d->path));
b = pa_streq(node, cd);
pa_xfree(cd);
return b;
}
static void inotify_cb(
pa_mainloop_api*a,
pa_io_event* e,
int fd,
pa_io_event_flags_t events,
void *userdata) {
struct {
struct inotify_event e;
char name[NAME_MAX];
} buf;
struct userdata *u = userdata;
static int type = 0;
pa_bool_t deleted = FALSE;
struct device *d;
void *state;
for (;;) {
ssize_t r;
struct inotify_event *event;
pa_zero(buf);
if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
if (r < 0 && errno == EAGAIN)
break;
pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
goto fail;
}
event = &buf.e;
while (r > 0) {
size_t len;
if ((size_t) r < sizeof(struct inotify_event)) {
pa_log("read() too short.");
goto fail;
}
len = sizeof(struct inotify_event) + event->len;
if ((size_t) r < len) {
pa_log("Payload missing.");
goto fail;
}
/* From udev we get the guarantee that the control
* device's ACL is changed last. To avoid races when ACLs
* are changed we hence watch only the control device */
if (((event->mask & IN_ATTRIB) && pa_startswith(event->name, "controlC")))
PA_HASHMAP_FOREACH(d, u->devices, state)
if (control_node_belongs_to_device(d, event->name))
d->need_verify = TRUE;
/* ALSA doesn't really give us any guarantee on the closing
* order, so let's simply hope */
if (((event->mask & IN_CLOSE_WRITE) && pa_startswith(event->name, "pcmC")))
PA_HASHMAP_FOREACH(d, u->devices, state)
if (pcm_node_belongs_to_device(d, event->name))
d->need_verify = TRUE;
/* /dev/snd/ might have been removed */
if ((event->mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
deleted = TRUE;
event = (struct inotify_event*) ((uint8_t*) event + len);
r -= len;
}
}
PA_HASHMAP_FOREACH(d, u->devices, state)
if (d->need_verify) {
d->need_verify = FALSE;
verify_access(u, d);
}
if (!deleted)
return;
fail:
if (u->inotify_io) {
a->io_free(u->inotify_io);
u->inotify_io = NULL;
}
if (u->inotify_fd >= 0) {
pa_close(u->inotify_fd);
u->inotify_fd = -1;
}
}
static int setup_inotify(struct userdata *u) {
int r;
if (u->inotify_fd >= 0)
return 0;
if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
return -1;
}
r = inotify_add_watch(u->inotify_fd, "/dev/snd", IN_ATTRIB|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
if (r < 0) {
int saved_errno = errno;
pa_close(u->inotify_fd);
u->inotify_fd = -1;
if (saved_errno == ENOENT) {
pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
return 0;
}
if (saved_errno == ENOSPC) {
pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
"I wished people would do their homework first and fix inotify before using it for watching whole "
"directory trees which is something the current inotify is certainly not useful for. "
"Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
return 0;
}
pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
return -1;
}
pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
return 0;
}
int pa__init(pa_module *m) {
struct userdata *u = NULL;
pa_modargs *ma;
struct udev_enumerate *enumerate = NULL;
struct udev_list_entry *item = NULL, *first = NULL;
int fd;
pa_bool_t use_tsched = TRUE, fixed_latency_range = FALSE, ignore_dB = FALSE, deferred_volume = m->core->deferred_volume;
pa_assert(m);
if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
pa_log("Failed to parse module arguments");
goto fail;
}
m->userdata = u = pa_xnew0(struct userdata, 1);
u->core = m->core;
u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
u->inotify_fd = -1;
if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
pa_log("Failed to parse tsched= argument.");
goto fail;
}
u->use_tsched = use_tsched;
if (pa_modargs_get_value_boolean(ma, "fixed_latency_range", &fixed_latency_range) < 0) {
pa_log("Failed to parse fixed_latency_range= argument.");
goto fail;
}
u->fixed_latency_range = fixed_latency_range;
if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
pa_log("Failed to parse ignore_dB= argument.");
goto fail;
}
u->ignore_dB = ignore_dB;
if (pa_modargs_get_value_boolean(ma, "deferred_volume", &deferred_volume) < 0) {
pa_log("Failed to parse deferred_volume= argument.");
goto fail;
}
u->deferred_volume = deferred_volume;
if (!(u->udev = udev_new())) {
pa_log("Failed to initialize udev library.");
goto fail;
}
if (setup_inotify(u) < 0)
goto fail;
if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
pa_log("Failed to initialize monitor.");
goto fail;
}
if (udev_monitor_filter_add_match_subsystem_devtype(u->monitor, "sound", NULL) < 0) {
pa_log("Failed to subscribe to sound devices.");
goto fail;
}
errno = 0;
if (udev_monitor_enable_receiving(u->monitor) < 0) {
pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
if (errno == EPERM)
pa_log_info("Most likely your kernel is simply too old and "
"allows only privileged processes to listen to device events. "
"Please upgrade your kernel to at least 2.6.30.");
goto fail;
}
if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
pa_log("Failed to get udev monitor fd.");
goto fail;
}
pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
if (!(enumerate = udev_enumerate_new(u->udev))) {
pa_log("Failed to initialize udev enumerator.");
goto fail;
}
if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
pa_log("Failed to match to subsystem.");
goto fail;
}
if (udev_enumerate_scan_devices(enumerate) < 0) {
pa_log("Failed to scan for devices.");
goto fail;
}
first = udev_enumerate_get_list_entry(enumerate);
udev_list_entry_foreach(item, first)
process_path(u, udev_list_entry_get_name(item));
udev_enumerate_unref(enumerate);
pa_log_info("Found %u cards.", pa_hashmap_size(u->devices));
pa_modargs_free(ma);
return 0;
fail:
if (enumerate)
udev_enumerate_unref(enumerate);
if (ma)
pa_modargs_free(ma);
pa__done(m);
return -1;
}
void pa__done(pa_module *m) {
struct userdata *u;
pa_assert(m);
if (!(u = m->userdata))
return;
if (u->udev_io)
m->core->mainloop->io_free(u->udev_io);
if (u->monitor)
udev_monitor_unref(u->monitor);
if (u->udev)
udev_unref(u->udev);
if (u->inotify_io)
m->core->mainloop->io_free(u->inotify_io);
if (u->inotify_fd >= 0)
pa_close(u->inotify_fd);
if (u->devices) {
struct device *d;
while ((d = pa_hashmap_steal_first(u->devices)))
device_free(d);
pa_hashmap_free(u->devices, NULL, NULL);
}
pa_xfree(u);
}
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