[RFC PATCH] Initial libudev input-hotplug support

Julien Cristau jcristau at debian.org
Tue Sep 29 14:54:44 PDT 2009


If libudev is found, we use that for hotplug and disable the hal and
dbus backends.
We look for event devices with an "x11_driver" property.  XKB
configuration happens using xkb.{rules,model,layout,variant,options}
properties, and arbitrary options can be set with "x11_options.foo"
(this is similar to the hal backend).

udev rules would look something like:
SUBSYSTEM=="input", KERNEL=="event*", ENV{x11_driver}="evdev"
SUBSYSTEM=="input", KERNEL=="event*", ENV{ID_CLASS}=="kbd", ENV{xkb.layout}="fr", ENV{xkb.options}="terminate:ctrl_alt_bksp,compose:lwin"

---
This seems to work fine on my laptop, with/without an USB mouse.  One
weird thing is the device names in udev contain quotes, so you get stuff
like:
(II) XINPUT: Adding extended input device ""AT Translated Set 2 keyboard"" (type: KEYBOARD)

Known issues/questions:
- add_option() should probably be shared with config/hal.c instead of
  duplicated, and the device_is_duplicate() logic should be used here as
  well
- I'm not quite sure about the Timer logic
- libudev doesn't give any error if it can't get to /sys or
  /dev/.udev/db, we just don't get any devices (this bit me when trying
  out this code in a chroot)
- what's the recommended way to avoid races between the 'enumerate' and
  'monitor' parts?

Any comments?

Cheers,
Julien

 config/Makefile.am              |   15 ++-
 config/config-backends.h        |   16 ++-
 config/config.c                 |    9 +-
 config/udev.c                   |  283 +++++++++++++++++++++++++++++++++++++++
 configure.ac                    |   22 +++-
 hw/xfree86/common/xf86Config.c  |    4 +
 hw/xfree86/common/xf86Globals.c |    2 +-
 include/dix-config.h.in         |    3 +
 8 files changed, 343 insertions(+), 11 deletions(-)
 create mode 100644 config/udev.c

diff --git a/config/Makefile.am b/config/Makefile.am
index 7fa2df8..80e2bb2 100644
--- a/config/Makefile.am
+++ b/config/Makefile.am
@@ -3,10 +3,18 @@ AM_CFLAGS = @DIX_CFLAGS@
 noinst_LTLIBRARIES = libconfig.la
 libconfig_la_SOURCES = config.c config-backends.h
 
+if CONFIG_UDEV
+
+AM_CFLAGS += @UDEV_CFLAGS@
+libconfig_la_SOURCES += udev.c
+libconfig_la_LIBADD = @UDEV_LIBS@
+
+else
+
 if CONFIG_NEED_DBUS
 AM_CFLAGS += @DBUS_CFLAGS@
 libconfig_la_SOURCES += dbus-core.c
-endif
+libconfig_la_LIBADD = @DBUS_LIBS@
 
 if CONFIG_DBUS_API
 dbusconfigdir = $(sysconfdir)/dbus-1/system.d
@@ -17,6 +25,11 @@ endif
 
 if CONFIG_HAL
 libconfig_la_SOURCES += hal.c
+libconfig_la_LIBADD += @HAL_LIBS@
 endif
 
+endif # CONFIG_NEED_DBUS
+
+endif # !CONFIG_UDEV
+
 EXTRA_DIST = xorg-server.conf x11-input.fdi
diff --git a/config/config-backends.h b/config/config-backends.h
index 907e86b..7cd930f 100644
--- a/config/config-backends.h
+++ b/config/config-backends.h
@@ -27,7 +27,12 @@
 #include <dix-config.h>
 #endif
 
-#ifdef CONFIG_NEED_DBUS
+#ifdef CONFIG_UDEV
+int config_udev_init(void);
+void config_udev_fini(void);
+#else
+
+# ifdef CONFIG_NEED_DBUS
 #include <dbus/dbus.h>
 
 typedef void (*config_dbus_core_connect_hook)(DBusConnection *connection,
@@ -46,14 +51,15 @@ int config_dbus_core_init(void);
 void config_dbus_core_fini(void);
 int config_dbus_core_add_hook(struct config_dbus_core_hook *hook);
 void config_dbus_core_remove_hook(struct config_dbus_core_hook *hook);
-#endif
+# endif
 
-#ifdef CONFIG_DBUS_API
+# ifdef CONFIG_DBUS_API
 int config_dbus_init(void);
 void config_dbus_fini(void);
-#endif
+# endif
 
-#ifdef CONFIG_HAL
+# ifdef CONFIG_HAL
 int config_hal_init(void);
 void config_hal_fini(void);
+# endif
 #endif
diff --git a/config/config.c b/config/config.c
index b013293..3d7df16 100644
--- a/config/config.c
+++ b/config/config.c
@@ -34,7 +34,10 @@
 void
 config_init(void)
 {
-#if defined(CONFIG_DBUS_API) || defined(CONFIG_HAL)
+#ifdef CONFIG_UDEV
+    if (!config_udev_init())
+        ErrorF("[config] failed to initialise udev\n");
+#elif defined(CONFIG_NEED_DBUS)
     if (config_dbus_core_init()) {
 # ifdef CONFIG_DBUS_API
        if (!config_dbus_init())
@@ -54,7 +57,9 @@ config_init(void)
 void
 config_fini(void)
 {
-#if defined(CONFIG_DBUS_API) || defined(CONFIG_HAL)
+#if defined(CONFIG_UDEV)
+    config_udev_fini();
+#elif defined(CONFIG_NEED_DBUS)
 # ifdef CONFIG_HAL
     config_hal_fini();
 # endif
diff --git a/config/udev.c b/config/udev.c
new file mode 100644
index 0000000..bc0a8ec
--- /dev/null
+++ b/config/udev.c
@@ -0,0 +1,283 @@
+/*
+ * Copyright © 2009 Julien Cristau
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Julien Cristau <jcristau at debian.org>
+ */
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include <libudev.h>
+
+#include "input.h"
+#include "inputstr.h"
+#include "hotplug.h"
+#include "config-backends.h"
+#include "os.h"
+
+#define UDEV_PROP_KEY "x11_options."
+#define UDEV_XKB_PROP_KEY "xkb."
+
+static void
+add_option(InputOption **options, const char *key, const char *value)
+{
+    if (!value || *value == '\0')
+        return;
+
+    for (; *options; options = &(*options)->next)
+        ;
+    *options = xcalloc(sizeof(**options), 1);
+    if (!*options) /* Yeesh. */
+        return;
+    (*options)->key = xstrdup(key);
+    (*options)->value = xstrdup(value);
+    (*options)->next = NULL;
+}
+
+static void
+device_added(struct udev_device *udev_device)
+{
+	const char *path = NULL, *driver = NULL, *name = NULL;
+	char *config_info = NULL;
+	const char *syspath;
+	const char *key, *value, *tmp;
+	InputOption *options = NULL, *tmpo;
+	DeviceIntPtr dev = NULL;
+	struct udev_list_entry *set, *entry;
+	struct udev_device *parent;
+	int rc;
+
+	driver = udev_device_get_property_value(udev_device, "x11_driver");
+
+	path = udev_device_get_devnode(udev_device);
+
+	syspath = udev_device_get_syspath(udev_device);
+
+	parent = udev_device_get_parent(udev_device);
+	if (parent)
+		name = udev_device_get_property_value(parent, "NAME");
+
+	if (!driver)
+		return;
+	if (!path)
+		return;
+	if (!syspath)
+		return;
+	options = xcalloc(sizeof(*options), 1);
+	if (!options)
+		return;
+
+	options->key = xstrdup("_source");
+	options->value = xstrdup("server/udev");
+	if (!options->key || !options->value)
+		goto unwind;
+
+	add_option(&options, "path", path);
+	add_option(&options, "device", path);
+	add_option(&options, "driver", driver);
+
+	config_info = xalloc(strlen(syspath) + 6); /* "udev:" + \0 */
+	if (!config_info)
+		goto unwind;
+	sprintf(config_info, "udev:%s", syspath);
+
+	set = udev_device_get_properties_list_entry(udev_device);
+	udev_list_entry_foreach(entry, set) {
+		key = udev_list_entry_get_name(entry);
+		if (!key)
+			continue;
+		if (!strncasecmp(key, UDEV_PROP_KEY, sizeof(UDEV_PROP_KEY) - 1)) {
+			value = udev_list_entry_get_value(entry);
+			add_option(&options, key + sizeof(UDEV_PROP_KEY) - 1, value);
+		} else if (!strncasecmp(key, UDEV_XKB_PROP_KEY, sizeof(UDEV_XKB_PROP_KEY) - 1)) {
+			tmp = key + sizeof(UDEV_XKB_PROP_KEY) - 1;
+			value = udev_list_entry_get_value(entry);
+			if (!strcasecmp(tmp, "rules"))
+				add_option(&options, "xkb_rules", value);
+			else if (!strcasecmp(tmp, "layout"))
+				add_option(&options, "xkb_layout", value);
+			else if (!strcasecmp(tmp, "variant"))
+				add_option(&options, "xkb_variant", value);
+			else if (!strcasecmp(tmp, "model"))
+				add_option(&options, "xkb_model", value);
+			else if (!strcasecmp(tmp, "options"))
+				add_option(&options, "xkb_options", value);
+		}
+	}
+	add_option(&options, "name", name ? name : "(unnamed)");
+	LogMessage(X_INFO, "config/udev: Adding input device %s (%s)\n",
+	           name, path);
+	rc = NewInputDeviceRequest(options, &dev);
+	if (rc != Success)
+		goto unwind;
+
+	for (; dev; dev = dev->next) {
+		xfree(dev->config_info);
+		dev->config_info = xstrdup(config_info);
+	}
+
+ unwind:
+	xfree(config_info);
+	while (!dev && (tmpo = options)) {
+		options = tmpo->next;
+		xfree(tmpo->key);
+		xfree(tmpo->value);
+		xfree(tmpo);
+	}
+
+	return;
+}
+
+static void
+remove_device(DeviceIntPtr dev)
+{
+	LogMessage(X_INFO, "config/udev: Removing input device %s\n", dev->name);
+	OsBlockSignals();
+	ProcessInputEvents();
+	DeleteInputDeviceRequest(dev);
+	OsReleaseSignals();
+}
+
+static void
+device_removed(struct udev_device *device)
+{
+	DeviceIntPtr dev, next;
+	char *value;
+	const char *syspath = udev_device_get_syspath(device);
+
+	value = xalloc(strlen(syspath) + 6); /* "udev:" + \0 */
+	if (!value)
+		return;
+	sprintf(value, "udev:%s", syspath);
+
+	for (dev = inputInfo.devices; dev; dev = next) {
+		next = dev->next;
+		if (dev->config_info && !strcmp(dev->config_info, value))
+			remove_device(dev);
+	}
+	for (dev = inputInfo.off_devices; dev; dev = next) {
+		next = dev->next;
+		if (dev->config_info && !strcmp(dev->config_info, value))
+			remove_device(dev);
+	}
+
+	xfree(value);
+}
+
+static void
+wakeup_handler(pointer data, int err, pointer read_mask)
+{
+	struct udev_monitor *udev_monitor = data;
+	int udev_fd = udev_monitor_get_fd(udev_monitor);
+	struct udev_device *udev_device;
+	const char *action;
+
+	if (err < 0)
+		return;
+
+	if (FD_ISSET(udev_fd, (fd_set *)read_mask)) {
+		udev_device = udev_monitor_receive_device(udev_monitor);
+		if (!udev_device)
+			return;
+		action = udev_device_get_action(udev_device);
+		if (!action)
+			;
+		else if (!strcmp(action, "add"))
+			device_added(udev_device);
+		else if (!strcmp(action, "remove"))
+			device_removed(udev_device);
+		else
+			ErrorF("config/udev: unhandled action %s\n", action);
+		udev_device_unref(udev_device);
+	}
+}
+
+static void
+block_handler(pointer data, struct timeval **tv, pointer read_mask)
+{
+}
+
+static struct udev_monitor *udev_monitor;
+static OsTimerPtr udev_timer;
+
+static CARD32
+connect_timer(OsTimerPtr timer, CARD32 time, pointer arg) {
+	int fd;
+	struct udev_enumerate *enumerate;
+	struct udev_list_entry *devices, *device;
+	struct udev *udev = udev_monitor_get_udev(udev_monitor);
+
+	fd = udev_monitor_get_fd(udev_monitor);
+	enumerate = udev_enumerate_new(udev);
+	udev_enumerate_add_match_subsystem(enumerate, "input");
+	udev_enumerate_scan_devices(enumerate);
+	if (udev_monitor_enable_receiving(udev_monitor)) {
+		ErrorF("config/udev: failed to bind the udev monitor\n");
+		goto unwind;
+	}
+	devices = udev_enumerate_get_list_entry(enumerate);
+	udev_list_entry_foreach(device, devices) {
+		const char *syspath = udev_list_entry_get_name(device);
+		struct udev_device *udev_device = udev_device_new_from_syspath(udev, syspath);
+		device_added(udev_device);
+		udev_device_unref(udev_device);
+	}
+	RegisterBlockAndWakeupHandlers(block_handler, wakeup_handler, udev_monitor);
+	AddGeneralSocket(fd);
+ unwind:
+	udev_enumerate_unref(enumerate);
+	if (udev_timer) {
+		TimerFree(udev_timer);
+		udev_timer = NULL;
+	}
+	return 0;
+}
+
+int
+config_udev_init(void) {
+	struct udev *udev;
+
+	udev = udev_new();
+	udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
+	if (!udev_monitor)
+		return 0;
+	udev_timer = TimerSet(NULL, 0, 1, connect_timer, NULL);
+	if (!udev_timer)
+		return 0;
+	return 1;
+}
+
+void
+config_udev_fini(void)
+{
+	struct udev *udev = udev_monitor_get_udev(udev_monitor);
+	if (udev_timer) {
+		TimerFree(udev_timer);
+		udev_timer = NULL;
+	}
+	RemoveGeneralSocket(udev_monitor_get_fd(udev_monitor));
+	RemoveBlockAndWakeupHandlers(block_handler, wakeup_handler, udev_monitor);
+	udev_monitor_unref(udev_monitor);
+	udev_monitor = NULL;
+	udev_unref(udev);
+}
diff --git a/configure.ac b/configure.ac
index 7fdcf5a..f14b93c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -586,6 +586,7 @@ AC_ARG_ENABLE(multibuffer,    AS_HELP_STRING([--enable-multibuffer], [Build Mult
 AC_ARG_ENABLE(dbe,            AS_HELP_STRING([--disable-dbe], [Build DBE extension (default: enabled)]), [DBE=$enableval], [DBE=yes])
 AC_ARG_ENABLE(xf86bigfont,    AS_HELP_STRING([--disable-xf86bigfont], [Build XF86 Big Font extension (default: disabled)]), [XF86BIGFONT=$enableval], [XF86BIGFONT=no])
 AC_ARG_ENABLE(dpms,           AS_HELP_STRING([--disable-dpms], [Build DPMS extension (default: enabled)]), [DPMSExtension=$enableval], [DPMSExtension=yes])
+AC_ARG_ENABLE(config-udev,    AS_HELP_STRING([--enable-config-udev], [Build udev support (default: auto)]), [CONFIG_UDEV=$enableval], [CONFIG_UDEV=auto])
 AC_ARG_ENABLE(config-dbus,    AS_HELP_STRING([--enable-config-dbus], [Build D-BUS API support (default: no)]), [CONFIG_DBUS_API=$enableval], [CONFIG_DBUS_API=no])
 AC_ARG_ENABLE(config-hal,     AS_HELP_STRING([--disable-config-hal], [Build HAL support (default: auto)]), [CONFIG_HAL=$enableval], [CONFIG_HAL=auto])
 AC_ARG_ENABLE(xfree86-utils,     AS_HELP_STRING([--enable-xfree86-utils], [Build xfree86 DDX utilities (default: enabled)]), [XF86UTILS=$enableval], [XF86UTILS=yes])
@@ -742,6 +743,25 @@ LIBXI="xi >= 1.2.99.1"
 LIBPCIACCESS="pciaccess >= 0.8.0"
 LIBGLIB="glib-2.0 >= 2.16"
 
+if test "x$CONFIG_UDEV" = xyes &&
+ { test "x$CONFIG_DBUS_API" = xyes || test "x$CONFIG_HAL" = xyes; }; then
+	AC_MSG_ERROR([Hotplugging through both libudev and dbus/hal not allowed])
+fi
+
+PKG_CHECK_MODULES(UDEV, libudev >= 143, [HAVE_LIBUDEV=yes], [HAVE_LIBUDEV=no])
+if test "x$CONFIG_UDEV" = xauto; then
+	CONFIG_UDEV="$HAVE_LIBUDEV"
+fi
+AM_CONDITIONAL(CONFIG_UDEV, [test "x$CONFIG_UDEV" = xyes])
+if test "x$CONFIG_UDEV" = xyes; then
+	CONFIG_DBUS_API=no
+	CONFIG_HAL=no
+	if ! test "x$HAVE_LIBUDEV" = xyes; then
+		AC_MSG_ERROR([udev configuration API requested, but libudev is not installed])
+	fi
+	AC_DEFINE(CONFIG_UDEV, 1, [Use libudev for input hotplug])
+fi
+
 dnl HAVE_DBUS is true if we actually have the D-Bus library, whereas
 dnl CONFIG_DBUS_API is true if we want to enable the D-Bus config
 dnl API.
@@ -774,13 +794,11 @@ if test "x$CONFIG_HAL" = xyes; then
 	fi
 
 	AC_DEFINE(CONFIG_HAL, 1, [Use the HAL hotplug API])
-        REQUIRED_LIBS="$REQUIRED_LIBS hal"
 	CONFIG_NEED_DBUS="yes"
 fi
 AM_CONDITIONAL(CONFIG_HAL, [test "x$CONFIG_HAL" = xyes])
 
 if test "x$CONFIG_NEED_DBUS" = xyes; then
-	REQUIRED_LIBS="$REQUIRED_LIBS dbus-1"
         AC_DEFINE(CONFIG_NEED_DBUS, 1, [Use D-Bus for input hotplug])
 fi
 AM_CONDITIONAL(CONFIG_NEED_DBUS, [test "x$CONFIG_NEED_DBUS" = xyes])
diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index 40f65bd..6a5d0f8 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -1457,6 +1457,10 @@ checkCoreInputDevices(serverLayoutPtr servlayoutp, Bool implicitLayout)
 	xf86Msg(X_INFO, "The server relies on HAL to provide the list of "
 	                "input devices.\n\tIf no devices become available, "
 	                "reconfigure HAL or disable AllowEmptyInput.\n");
+#elif CONFIG_UDEV
+	xf86Msg(X_INFO, "The server relies on udev to provide the list of "
+	                "input devices.\n\tIf no devices become available, "
+	                "reconfigure udev or disable AllowEmptyInput.\n");
 #else
 	xf86Msg(X_INFO, "HAL is disabled and no input devices were configured.\n"
 			"\tTry disabling AllowEmptyInput.\n");
diff --git a/hw/xfree86/common/xf86Globals.c b/hw/xfree86/common/xf86Globals.c
index d8f7f7f..0b310e8 100644
--- a/hw/xfree86/common/xf86Globals.c
+++ b/hw/xfree86/common/xf86Globals.c
@@ -132,7 +132,7 @@ xf86InfoRec xf86Info = {
     .kbdCustomKeycodes          = FALSE,
     .disableRandR               = FALSE,
     .randRFrom                  = X_DEFAULT,
-#ifdef CONFIG_HAL
+#if defined(CONFIG_HAL) || defined(CONFIG_UDEV)
     .allowEmptyInput            = TRUE,
     .autoAddDevices             = TRUE,
     .autoEnableDevices          = TRUE
diff --git a/include/dix-config.h.in b/include/dix-config.h.in
index 798d9e7..423ba3a 100644
--- a/include/dix-config.h.in
+++ b/include/dix-config.h.in
@@ -384,6 +384,9 @@
 /* Support D-Bus */
 #undef HAVE_DBUS
 
+/* Use libudev for input hotplug */
+#undef CONFIG_UDEV
+
 /* Use D-Bus for input hotplug */
 #undef CONFIG_NEED_DBUS
 
-- 
1.6.4.3



More information about the xorg-devel mailing list