GopherProxy

	Use the sioctl_open(3) OpenBSD API to access vol - slstatus - status monitor
	git clone git://git.suckless.org/slstatus
	Log
	Files
	Refs
	README
	LICENSE
	---
	commit 9ac721c23fb640de2a6d1f84c84a79b2ccc26691
	parent aaf279f6ddfb48146fc1a579efd83a55722910b5
	Author: Ingo Feinerer <[email protected]>
	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:
	M components/volume.c \| 210 +++++++++++++++++++++++------…
	M config.def.h \| 1 +
	M config.mk \| 1 +

	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_LEVE…
	- (mc.un.value.level[AUDIO_MIXER_LEV…
	- mc.un.value.level[AUDIO_MIXER_LEV…
	- mc.un.value.level[AUDIO_MIXER_LEV…
	- mc.un.value.level[AUDIO_MIXER_LEV…
	- 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