Implement a node device backend using libudev

* configure.in: add new --with-udev, disabled by default, and requiring
  libudev > 145
* src/node_device/node_device_udev.c src/node_device/node_device_udev.h:
  the new node device backend
* src/node_device/node_device_linux_sysfs.c: moved node_device_hal_linux.c
  to a better file name
* src/conf/node_device_conf.c src/conf/node_device_conf.h: add a couple
  of fields in node device definitions, and an API to look them up,
  remove a couple of unused fields from previous patch.
* src/node_device/node_device_driver.c src/node_device/node_device_driver.h:
  plug the new driver
* po/POTFILES.in src/Makefile.am src/libvirt_private.syms: add the new
  files and symbols
* src/util/util.h src/util/util.c: add a new convenience macro
  virBuildPath and virBuildPathInternal() function

configure.in

@@ -1654,7 +1654,7 @@ test "$enable_shared" = no && lt_cv_objdir=.
 LV_LIBTOOL_OBJDIR=${lt_cv_objdir-.}
 AC_SUBST([LV_LIBTOOL_OBJDIR])
 
-dnl HAL or DeviceKit library for host device enumeration
+dnl HAL, DeviceKit, or libudev library for host device enumeration
 HAL_REQUIRED=0.0
 HAL_CFLAGS=
 HAL_LIBS=
@@ -1748,8 +1748,46 @@ AM_CONDITIONAL([HAVE_DEVKIT], [test "x$with_devkit" = "xyes"])
 AC_SUBST([DEVKIT_CFLAGS])
 AC_SUBST([DEVKIT_LIBS])
 
+UDEV_REQUIRED=145
+UDEV_CFLAGS=
+UDEV_LIBS=
+AC_ARG_WITH([udev],
+  [  --with-udev        use libudev for host device enumeration],
+  [],
+  [with_udev=check])
+
+if test "$with_libvirtd" = "no" ; then
+  with_udev=no
+fi
+if test "x$with_udev" = "xyes" -o "x$with_udev" = "xcheck"; then
+  PKG_CHECK_MODULES(UDEV, libudev >= $UDEV_REQUIRED,
+    [with_udev=yes], [
+    if test "x$with_udev" = "xcheck" ; then
+       with_udev=no
+    else
+       AC_MSG_ERROR(
+         [You must install libudev-devel >= $UDEV_REQUIRED to compile libvirt])
+    fi
+  ])
+  if test "x$with_udev" = "xyes" ; then
+    AC_DEFINE_UNQUOTED([HAVE_UDEV], 1,
+      [use UDEV for host device enumeration])
+
+    old_CFLAGS=$CFLAGS
+    old_LDFLAGS=$LDFLAGS
+    CFLAGS="$CFLAGS $UDEV_CFLAGS"
+    LDFLAGS="$LDFLAGS $UDEV_LIBS"
+    AC_CHECK_FUNCS([udev_new],,[with_udev=no])
+    CFLAGS="$old_CFLAGS"
+    LDFLAGS="$old_LDFLAGS"
+  fi
+fi
+AM_CONDITIONAL([HAVE_UDEV], [test "x$with_udev" = "xyes"])
+AC_SUBST([UDEV_CFLAGS])
+AC_SUBST([UDEV_LIBS])
+
 with_nodedev=no;
-if test "$with_devkit" = "yes" -o "$with_hal" = "yes";
+if test "$with_devkit" = "yes" -o "$with_hal" = "yes" -o "$with_udev" = "yes";
 then
   with_nodedev=yes
   AC_DEFINE_UNQUOTED([WITH_NODE_DEVICES], 1, [with node device driver])
@@ -1914,6 +1952,11 @@ AC_MSG_NOTICE([  devkit: $DEVKIT_CFLAGS $DEVKIT_LIBS])
 else
 AC_MSG_NOTICE([  devkit: no])
 fi
+if test "$with_udev" = "yes" ; then
+AC_MSG_NOTICE([    udev: $UDEV_CFLAGS $UDEV_LIBS])
+else
+AC_MSG_NOTICE([    udev: no])
+fi
 if test "$with_netcf" = "yes" ; then
 AC_MSG_NOTICE([   netcf: $NETCF_CFLAGS $NETCF_LIBS])
 else

daemon/libvirtd.c

@@ -877,8 +877,7 @@ static struct qemud_server *qemudInitialize(void) {
 #ifdef WITH_STORAGE_DIR
     storageRegister();
 #endif
-#if defined(WITH_NODE_DEVICES) && \
-    (defined(HAVE_HAL) || defined(HAVE_DEVKIT))
+#if defined(WITH_NODE_DEVICES)
     nodedevRegister();
 #endif
     secretRegister();

po/POTFILES.in

@@ -17,7 +17,8 @@ src/lxc/lxc_controller.c
 src/lxc/lxc_driver.c
 src/network/bridge_driver.c
 src/node_device/node_device_driver.c
-src/node_device/node_device_hal_linux.c
+src/node_device/node_device_linux_sysfs.c
+src/node_device/node_device_udev.c
 src/nodeinfo.c
 src/opennebula/one_conf.c
 src/opennebula/one_driver.c

src/Makefile.am

@@ -259,16 +259,20 @@ SECURITY_DRIVER_APPARMOR_SOURCES =				\
 
 
 NODE_DEVICE_DRIVER_SOURCES =					\
-		node_device/node_device_driver.c node_device/node_device_driver.h
+		node_device/node_device_driver.c \
+		node_device/node_device_driver.h \
+		node_device/node_device_linux_sysfs.c
 
 NODE_DEVICE_DRIVER_HAL_SOURCES =				\
 		node_device/node_device_hal.c			\
-		node_device/node_device_hal.h			\
-		node_device/node_device_hal_linux.c
+		node_device/node_device_hal.h
 
 NODE_DEVICE_DRIVER_DEVKIT_SOURCES =				\
 		node_device/node_device_devkit.c
 
+NODE_DEVICE_DRIVER_UDEV_SOURCES =				\
+		node_device/node_device_udev.c
+
 
 #########################
 #
@@ -647,6 +651,11 @@ libvirt_driver_nodedev_la_SOURCES += $(NODE_DEVICE_DRIVER_DEVKIT_SOURCES)
 libvirt_driver_nodedev_la_CFLAGS += $(DEVKIT_CFLAGS)
 libvirt_driver_nodedev_la_LDFLAGS += $(DEVKIT_LIBS)
 endif
+if HAVE_UDEV
+libvirt_driver_nodedev_la_SOURCES += $(NODE_DEVICE_DRIVER_UDEV_SOURCES)
+libvirt_driver_nodedev_la_CFLAGS += $(UDEV_CFLAGS)
+libvirt_driver_nodedev_la_LDFLAGS += $(UDEV_LIBS)
+endif
 
 if WITH_DRIVER_MODULES
 libvirt_driver_nodedev_la_LDFLAGS += -module -avoid-version
@@ -696,6 +705,7 @@ EXTRA_DIST +=							\
 		$(NODE_DEVICE_DRIVER_SOURCES)			\
 		$(NODE_DEVICE_DRIVER_HAL_SOURCES)		\
 		$(NODE_DEVICE_DRIVER_DEVKIT_SOURCES)		\
+		$(NODE_DEVICE_DRIVER_UDEV_SOURCES)		\
 		$(SECURITY_DRIVER_SELINUX_SOURCES)		\
 		$(SECURITY_DRIVER_APPARMOR_SOURCES)		\
 		$(SECRET_DRIVER_SOURCES)			\

src/conf/node_device_conf.c

@@ -91,6 +91,26 @@ int virNodeDeviceHasCap(const virNodeDeviceObjPtr dev, const char *cap)
     return 0;
 }
 
+
+virNodeDeviceObjPtr
+virNodeDeviceFindBySysfsPath(const virNodeDeviceObjListPtr devs,
+                             const char *sysfs_path)
+{
+    unsigned int i;
+
+    for (i = 0; i < devs->count; i++) {
+        virNodeDeviceObjLock(devs->objs[i]);
+        if ((devs->objs[i]->def->sysfs_path != NULL) &&
+            (STREQ(devs->objs[i]->def->sysfs_path, sysfs_path))) {
+            return devs->objs[i];
+        }
+        virNodeDeviceObjUnlock(devs->objs[i]);
+    }
+
+    return NULL;
+}
+
+
 virNodeDeviceObjPtr virNodeDeviceFindByName(const virNodeDeviceObjListPtr devs,
                                             const char *name)
 {
@@ -117,6 +137,8 @@ void virNodeDeviceDefFree(virNodeDeviceDefPtr def)
     VIR_FREE(def->name);
     VIR_FREE(def->parent);
     VIR_FREE(def->driver);
+    VIR_FREE(def->sysfs_path);
+    VIR_FREE(def->parent_sysfs_path);
 
     caps = def->caps;
     while (caps) {
@@ -228,9 +250,17 @@ char *virNodeDeviceDefFormat(virConnectPtr conn,
 
     virBufferAddLit(&buf, "<device>\n");
     virBufferEscapeString(&buf, "  <name>%s</name>\n", def->name);
-
-    if (def->parent)
+    if (def->sysfs_path != NULL) {
+        virBufferEscapeString(&buf, "  <sysfs_path>%s</sysfs_path>\n",
+                              def->sysfs_path);
+    }
+    if (def->parent) {
         virBufferEscapeString(&buf, "  <parent>%s</parent>\n", def->parent);
+    }
+    if (def->parent_sysfs_path != NULL) {
+        virBufferEscapeString(&buf, "  <parent_sysfs_path>%s</parent_sysfs_path>\n",
+                              def->parent_sysfs_path);
+    }
     if (def->driver) {
         virBufferAddLit(&buf, "  <driver>\n");
         virBufferEscapeString(&buf, "    <name>%s</name>\n", def->driver);
@@ -248,12 +278,6 @@ char *virNodeDeviceDefFormat(virConnectPtr conn,
             if (data->system.product_name)
                 virBufferEscapeString(&buf, "    <product>%s</product>\n",
                                       data->system.product_name);
-            if (data->system.dmi_devpath)
-                virBufferEscapeString(&buf, "    <dmi_devpath>%s</dmi_devpath>\n",
-                                      data->system.dmi_devpath);
-            if (data->system.description)
-                virBufferEscapeString(&buf, "    <description>%s</description>\n",
-                                      data->system.description);
             virBufferAddLit(&buf, "    <hardware>\n");
             if (data->system.hardware.vendor_name)
                 virBufferEscapeString(&buf, "      <vendor>%s</vendor>\n",
@@ -331,9 +355,6 @@ char *virNodeDeviceDefFormat(virConnectPtr conn,
                               data->usb_if.subclass);
             virBufferVSprintf(&buf, "    <protocol>%d</protocol>\n",
                               data->usb_if.protocol);
-            if (data->usb_if.interface_name)
-                virBufferVSprintf(&buf, "    <interface_name>%s</interface_name>\n",
-                                  data->usb_if.interface_name);
             if (data->usb_if.description)
                 virBufferVSprintf(&buf, "    <description>%s</description>\n",
                                   data->usb_if.description);
@@ -1340,8 +1361,6 @@ void virNodeDevCapsDefFree(virNodeDevCapsDefPtr caps)
     switch (caps->type) {
     case VIR_NODE_DEV_CAP_SYSTEM:
         VIR_FREE(data->system.product_name);
-        VIR_FREE(data->system.dmi_devpath);
-        VIR_FREE(data->system.description);
         VIR_FREE(data->system.hardware.vendor_name);
         VIR_FREE(data->system.hardware.version);
         VIR_FREE(data->system.hardware.serial);
@@ -1358,7 +1377,6 @@ void virNodeDevCapsDefFree(virNodeDevCapsDefPtr caps)
         VIR_FREE(data->usb_dev.vendor_name);
         break;
     case VIR_NODE_DEV_CAP_USB_INTERFACE:
-        VIR_FREE(data->usb_if.interface_name);
         VIR_FREE(data->usb_if.description);
         break;
     case VIR_NODE_DEV_CAP_NET:

src/conf/node_device_conf.h

@@ -82,8 +82,6 @@ struct _virNodeDevCapsDef {
     union _virNodeDevCapData {
         struct {
             char *product_name;
-            char *description;
-            char *dmi_devpath;
             struct {
                 char *vendor_name;
                 char *version;
@@ -120,7 +118,6 @@ struct _virNodeDevCapsDef {
             unsigned _class;		/* "class" is reserved in C */
             unsigned subclass;
             unsigned protocol;
-            char *interface_name;
             char *description;
         } usb_if;
         struct {
@@ -164,7 +161,9 @@ typedef struct _virNodeDeviceDef virNodeDeviceDef;
 typedef virNodeDeviceDef *virNodeDeviceDefPtr;
 struct _virNodeDeviceDef {
     char *name;                         /* device name (unique on node) */
+    char *sysfs_path;                   /* udev name/sysfs path */
     char *parent;			/* optional parent device name */
+    char *parent_sysfs_path;            /* udev parent name/sysfs path */
     char *driver;                       /* optional driver name */
     virNodeDevCapsDefPtr caps;		/* optional device capabilities */
 };
@@ -206,6 +205,9 @@ int virNodeDeviceHasCap(const virNodeDeviceObjPtr dev, const char *cap);
 
 virNodeDeviceObjPtr virNodeDeviceFindByName(const virNodeDeviceObjListPtr devs,
                                             const char *name);
+virNodeDeviceObjPtr
+virNodeDeviceFindBySysfsPath(const virNodeDeviceObjListPtr devs,
+                             const char *sysfs_path);
 
 virNodeDeviceObjPtr virNodeDeviceAssignDef(virConnectPtr conn,
                                            virNodeDeviceObjListPtr devs,

src/libvirt_private.syms

@@ -341,6 +341,7 @@ virNodeDeviceHasCap;
 virNodeDeviceObjRemove;
 virNodeDevCapTypeToString;
 virNodeDeviceFindByName;
+virNodeDeviceFindBySysfsPath;
 virNodeDeviceObjListFree;
 virNodeDeviceDefFree;
 virNodeDevCapsDefFree;

src/node_device/node_device_driver.c

@@ -70,7 +70,10 @@ static int update_caps(virNodeDeviceObjPtr dev)
 }
 
 
-#ifdef __linux__
+#if defined (__linux__) && defined (HAVE_HAL)
+/* Under libudev changes to the driver name should be picked up as
+ * "change" events, so we don't call update driver name unless we're
+ * using the HAL backend. */
 static int update_driver_name(virConnectPtr conn,
                               virNodeDeviceObjPtr dev)
 {
@@ -658,10 +661,10 @@ void registerCommonNodeFuncs(virDeviceMonitorPtr driver)
 
 
 int nodedevRegister(void) {
-#if defined(HAVE_HAL) && defined(HAVE_DEVKIT)
+#if defined(HAVE_HAL) && defined(HAVE_UDEV)
     /* Register only one of these two - they conflict */
     if (halNodeRegister() == -1)
-        return devkitNodeRegister();
+        return udevNodeRegister();
     return 0;
 #else
 #ifdef HAVE_HAL
@@ -670,5 +673,8 @@ int nodedevRegister(void) {
 #ifdef HAVE_DEVKIT
     return devkitNodeRegister();
 #endif
+#ifdef HAVE_UDEV
+    return udevNodeRegister();
+#endif
 #endif
 }

src/node_device/node_device_driver.h

@@ -45,6 +45,9 @@ int halNodeRegister(void);
 #ifdef HAVE_DEVKIT
 int devkitNodeRegister(void);
 #endif
+#ifdef HAVE_UDEV
+int udevNodeRegister(void);
+#endif
 
 void nodeDeviceLock(virDeviceMonitorStatePtr driver);
 void nodeDeviceUnlock(virDeviceMonitorStatePtr driver);
@@ -53,4 +56,23 @@ void registerCommonNodeFuncs(virDeviceMonitorPtr mon);
 
 int nodedevRegister(void);
 
+#ifdef __linux__
+
+#define check_fc_host(d) check_fc_host_linux(d)
+int check_fc_host_linux(union _virNodeDevCapData *d);
+
+#define check_vport_capable(d) check_vport_capable_linux(d)
+int check_vport_capable_linux(union _virNodeDevCapData *d);
+
+#define read_wwn(host, file, wwn) read_wwn_linux(host, file, wwn)
+int read_wwn_linux(int host, const char *file, char **wwn);
+
+#else  /* __linux__ */
+
+#define check_fc_host(d)
+#define check_vport_capable(d)
+#define read_wwn(host, file, wwn)
+
+#endif /* __linux__ */
+
 #endif /* __VIR_NODE_DEVICE_H__ */

src/node_device/node_device_hal.h

@@ -22,23 +22,4 @@
 #ifndef __VIR_NODE_DEVICE_HAL_H__
 #define __VIR_NODE_DEVICE_HAL_H__
 
-#ifdef __linux__
-
-#define check_fc_host(d) check_fc_host_linux(d)
-int check_fc_host_linux(union _virNodeDevCapData *d);
-
-#define check_vport_capable(d) check_vport_capable_linux(d)
-int check_vport_capable_linux(union _virNodeDevCapData *d);
-
-#define read_wwn(host, file, wwn) read_wwn_linux(host, file, wwn)
-int read_wwn_linux(int host, const char *file, char **wwn);
-
-#else  /* __linux__ */
-
-#define check_fc_host(d)
-#define check_vport_capable(d)
-#define read_wwn(host, file, wwn)
-
-#endif /* __linux__ */
-
 #endif /* __VIR_NODE_DEVICE_HAL_H__ */

src/node_device/node_device_udev.h

+/*
+ * node_device_udev.h: node device enumeration - libudev implementation
+ *
+ * Copyright (C) 2009 Red Hat
+ *
+ * This library 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.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+ *
+ * Author: Dave Allan <dallan@redhat.com>
+ */
+
+#include <libudev.h>
+#include <stdint.h>
+
+#define SYSFS_DATA_SIZE 4096
+#define DRV_STATE_UDEV_MONITOR(ds) ((struct udev_monitor *)((ds)->privateData))
+#define DMI_DEVPATH "/sys/devices/virtual/dmi/id"
+#define PROPERTY_FOUND 0
+#define PROPERTY_MISSING 1
+#define PROPERTY_ERROR -1

src/util/util.c

@@ -2128,3 +2128,31 @@ void virFileWaitForDevices(virConnectPtr conn)
 void virFileWaitForDevices(virConnectPtr conn ATTRIBUTE_UNUSED) {}
 #endif
 #endif
+
+int virBuildPathInternal(char **path, ...)
+{
+    char *path_component = NULL;
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    va_list ap;
+    int ret = 0;
+
+    va_start(ap, *path);
+
+    path_component = va_arg(ap, char *);
+    virBufferAdd(&buf, path_component, -1);
+
+    while ((path_component = va_arg(ap, char *)) != NULL)
+    {
+        virBufferAddChar(&buf, '/');
+        virBufferAdd(&buf, path_component, -1);
+    }
+
+    va_end(ap);
+
+    *path = virBufferContentAndReset(&buf);
+    if (*path == NULL) {
+        ret = -1;
+    }
+
+    return ret;
+}

src/util/util.h

@@ -248,4 +248,7 @@ char *virFileFindMountPoint(const char *type);
 
 void virFileWaitForDevices(virConnectPtr conn);
 
+#define virBuildPath(path, ...) virBuildPathInternal(path, __VA_ARGS__, NULL)
+int virBuildPathInternal(char **path, ...) ATTRIBUTE_SENTINEL;
+
 #endif /* __VIR_UTIL_H__ */