commit 9ac721c23fb640de2a6d1f84c84a79b2ccc26691
parent aaf279f6ddfb48146fc1a579efd83a55722910b5
Author: Ingo Feinerer <feinerer@logic.at>
Date: Sat, 9 May 2020 12:03:20 +0200
Use the sioctl_open(3) OpenBSD API to access vol
Starting with OpenBSD 6.7 regular users cannot access raw audio devices
anymore, for improved security.
Instead use the sioctl_open(3) API to access and manipulate audio
controls exposed by sndiod(8). On the first call a permanent connection
is established with the running sndiod daemon, and call-back functions
are registered which are triggered when audio controls are changed
(e.g., a USB headset is attached) or when the volume is modified. On
subsequent calls we poll for changes; if there are no volume changes
this costs virtually nothing.
Joint work with Alexandre Ratchov
Diffstat:
3 files changed, 161 insertions(+), 51 deletions(-)
diff --git a/components/volume.c b/components/volume.c
@@ -8,69 +8,177 @@
#include "../util.h"
#if defined(__OpenBSD__)
- #include <sys/audioio.h>
+ #include <sys/queue.h>
+ #include <poll.h>
+ #include <sndio.h>
+ #include <stdlib.h>
+
+ struct control {
+ LIST_ENTRY(control) next;
+ unsigned int addr;
+ #define CTRL_NONE 0
+ #define CTRL_LEVEL 1
+ #define CTRL_MUTE 2
+ unsigned int type;
+ unsigned int maxval;
+ unsigned int val;
+ };
+
+ static LIST_HEAD(, control) controls = LIST_HEAD_INITIALIZER(controls);
+ static struct pollfd *pfds;
+ static struct sioctl_hdl *hdl;
+ static int initialized;
+
+ /*
+ * Call-back to obtain the description of all audio controls.
+ */
+ static void
+ ondesc(void *unused, struct sioctl_desc *desc, int val)
+ {
+ struct control *c, *ctmp;
+ unsigned int type = CTRL_NONE;
+
+ if (desc == NULL)
+ return;
+
+ /* Delete existing audio control with the same address. */
+ LIST_FOREACH_SAFE(c, &controls, next, ctmp) {
+ if (desc->addr == c->addr) {
+ LIST_REMOVE(c, next);
+ free(c);
+ break;
+ }
+ }
+
+ /* Only match output.level and output.mute audio controls. */
+ if (desc->group[0] != 0 ||
+ strcmp(desc->node0.name, "output") != 0)
+ return;
+ if (desc->type == SIOCTL_NUM &&
+ strcmp(desc->func, "level") == 0)
+ type = CTRL_LEVEL;
+ else if (desc->type == SIOCTL_SW &&
+ strcmp(desc->func, "mute") == 0)
+ type = CTRL_MUTE;
+ else
+ return;
+
+ c = malloc(sizeof(struct control));
+ if (c == NULL) {
+ warn("sndio: failed to allocate audio control\n");
+ return;
+ }
+
+ c->addr = desc->addr;
+ c->type = type;
+ c->maxval = desc->maxval;
+ c->val = val;
+ LIST_INSERT_HEAD(&controls, c, next);
+ }
+
+ /*
+ * Call-back invoked whenever an audio control changes.
+ */
+ static void
+ onval(void *unused, unsigned int addr, unsigned int val)
+ {
+ struct control *c;
+
+ LIST_FOREACH(c, &controls, next) {
+ if (c->addr == addr)
+ break;
+ }
+ c->val = val;
+ }
+
+ static void
+ cleanup(void)
+ {
+ struct control *c;
+
+ if (hdl) {
+ sioctl_close(hdl);
+ hdl = NULL;
+ }
+
+ free(pfds);
+ pfds = NULL;
+
+ while (!LIST_EMPTY(&controls)) {
+ c = LIST_FIRST(&controls);
+ LIST_REMOVE(c, next);
+ free(c);
+ }
+ }
+
+ static int
+ init(void)
+ {
+ hdl = sioctl_open(SIO_DEVANY, SIOCTL_READ, 0);
+ if (hdl == NULL) {
+ warn("sndio: cannot open device");
+ goto failed;
+ }
+
+ if (!sioctl_ondesc(hdl, ondesc, NULL)) {
+ warn("sndio: cannot set control description call-back");
+ goto failed;
+ }
+
+ if (!sioctl_onval(hdl, onval, NULL)) {
+ warn("sndio: cannot set control values call-back");
+ goto failed;
+ }
+
+ pfds = calloc(sioctl_nfds(hdl), sizeof(struct pollfd));
+ if (pfds == NULL) {
+ warn("sndio: cannot allocate pollfd structures");
+ goto failed;
+ }
+
+ return 1;
+ failed:
+ cleanup();
+ return 0;
+ }
const char *
- vol_perc(const char *card)
+ vol_perc(const char *unused)
{
- static int cls = -1;
- mixer_devinfo_t mdi;
- mixer_ctrl_t mc;
- int afd = -1, m = -1, v = -1;
+ struct control *c;
+ int n, v, value;
- if ((afd = open(card, O_RDONLY)) < 0) {
- warn("open '%s':", card);
+ if (!initialized)
+ initialized = init();
+
+ if (hdl == NULL)
return NULL;
- }
- for (mdi.index = 0; cls == -1; mdi.index++) {
- if (ioctl(afd, AUDIO_MIXER_DEVINFO, &mdi) < 0) {
- warn("ioctl 'AUDIO_MIXER_DEVINFO':");
- close(afd);
- return NULL;
- }
- if (mdi.type == AUDIO_MIXER_CLASS &&
- !strncmp(mdi.label.name,
- AudioCoutputs,
- MAX_AUDIO_DEV_LEN))
- cls = mdi.index;
- }
- for (mdi.index = 0; v == -1 || m == -1; mdi.index++) {
- if (ioctl(afd, AUDIO_MIXER_DEVINFO, &mdi) < 0) {
- warn("ioctl 'AUDIO_MIXER_DEVINFO':");
- close(afd);
- return NULL;
- }
- if (mdi.mixer_class == cls &&
- ((mdi.type == AUDIO_MIXER_VALUE &&
- !strncmp(mdi.label.name,
- AudioNmaster,
- MAX_AUDIO_DEV_LEN)) ||
- (mdi.type == AUDIO_MIXER_ENUM &&
- !strncmp(mdi.label.name,
- AudioNmute,
- MAX_AUDIO_DEV_LEN)))) {
- mc.dev = mdi.index, mc.type = mdi.type;
- if (ioctl(afd, AUDIO_MIXER_READ, &mc) < 0) {
- warn("ioctl 'AUDIO_MIXER_READ':");
- close(afd);
+ n = sioctl_pollfd(hdl, pfds, POLLIN);
+ if (n > 0) {
+ n = poll(pfds, n, 0);
+ if (n > 0) {
+ if (sioctl_revents(hdl, pfds) & POLLHUP) {
+ warn("sndio: disconnected");
+ cleanup();
return NULL;
}
- if (mc.type == AUDIO_MIXER_VALUE)
- v = mc.un.value.num_channels == 1 ?
- mc.un.value.level[AUDIO_MIXER_LEVEL_MONO] :
- (mc.un.value.level[AUDIO_MIXER_LEVEL_LEFT] >
- mc.un.value.level[AUDIO_MIXER_LEVEL_RIGHT] ?
- mc.un.value.level[AUDIO_MIXER_LEVEL_LEFT] :
- mc.un.value.level[AUDIO_MIXER_LEVEL_RIGHT]);
- else if (mc.type == AUDIO_MIXER_ENUM)
- m = mc.un.ord;
}
}
- close(afd);
+ value = 100;
+ LIST_FOREACH(c, &controls, next) {
+ if (c->type == CTRL_MUTE && c->val == 1)
+ value = 0;
+ else if (c->type == CTRL_LEVEL) {
+ v = (c->val * 100 + c->maxval / 2) / c->maxval;
+ /* For multiple channels return the minimum. */
+ if (v < value)
+ value = v;
+ }
+ }
- return bprintf("%d", m ? 0 : v * 100 / 255);
+ return bprintf("%d", value);
}
#else
#include <sys/soundcard.h>
diff --git a/config.def.h b/config.def.h
@@ -59,6 +59,7 @@ static const char unknown_str[] = "n/a";
* uptime system uptime NULL
* username username of current user NULL
* vol_perc OSS/ALSA volume in percent mixer file (/dev/mixer)
+ * NULL on OpenBSD
* wifi_perc WiFi signal in percent interface name (wlan0)
* wifi_essid WiFi ESSID interface name (wlan0)
*/
diff --git a/config.mk b/config.mk
@@ -14,6 +14,7 @@ X11LIB = /usr/X11R6/lib
CPPFLAGS = -I$(X11INC) -D_DEFAULT_SOURCE
CFLAGS = -std=c99 -pedantic -Wall -Wextra -Os
LDFLAGS = -L$(X11LIB) -s
+# OpenBSD: add -lsndio
LDLIBS = -lX11
# compiler and linker