datapath: Add sysfs support for all (otherwise supported) Linux versions.

This turned out to be less trouble than I expected.

This builds successfully against 2.6.18 through 2.6.28.  Justin has lightly
tested it on a 2.6.27 kernel provided by Citrix.

9 files changed, 121 insertions, 105 deletions

diff --git a/datapath/brc_sysfs.h b/datapath/brc_sysfs.h
index 0c72fb22..245492f4 100644
--- a/datapath/brc_sysfs.h
+++ b/datapath/brc_sysfs.h
@@ -12,14 +12,5 @@ int brc_sysfs_del_dp(struct datapath *dp);
 int brc_sysfs_add_if(struct net_bridge_port *p);
 int brc_sysfs_del_if(struct net_bridge_port *p);
 
-#include <linux/version.h>
-#if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,18)
-#define SUPPORT_SYSFS 1
-#else
-/* We only support sysfs on Linux 2.6.18 because that's the only place we
- * really need it (on Xen, for brcompat) and it's a big pain to try to support
- * multiple versions. */
-#endif
-
 #endif /* brc_sysfs.h */
 
diff --git a/datapath/brc_sysfs_dp.c b/datapath/brc_sysfs_dp.c
index fc02f279..6b5dd5cc 100644
--- a/datapath/brc_sysfs_dp.c
+++ b/datapath/brc_sysfs_dp.c
@@ -20,22 +20,26 @@
 #include "datapath.h"
 #include "dp_dev.h"
 
-#ifdef SUPPORT_SYSFS
+#ifdef CONFIG_SYSFS
 #define to_dev(obj)	container_of(obj, struct device, kobj)
 
 /* Hack to attempt to build on more platforms. */
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)
-#define to_kobj(d) &(d)->class_dev.kobj
 #define BRC_DEVICE_ATTR CLASS_DEVICE_ATTR
+#define DEVICE_PARAMS struct class_device *d
+#define DEVICE_ARGS d
+#define DEV_ATTR(NAME) class_device_attr_##NAME
 #else
-#define to_kobj(d) &(d)->dev.kobj
 #define BRC_DEVICE_ATTR DEVICE_ATTR
+#define DEVICE_PARAMS struct device *d, struct device_attribute *attr
+#define DEVICE_ARGS d, attr
+#define DEV_ATTR(NAME) dev_attr_##NAME
 #endif
 
 /*
  * Common code for storing bridge parameters.
  */
-static ssize_t store_bridge_parm(struct class_device *d,
+static ssize_t store_bridge_parm(DEVICE_PARAMS,
 				 const char *buf, size_t len,
 				 void (*set)(struct datapath *, unsigned long))
 {
@@ -68,8 +72,7 @@ static ssize_t store_bridge_parm(struct class_device *d,
 }
 
 
-static ssize_t show_forward_delay(struct class_device *d,
-				  char *buf)
+static ssize_t show_forward_delay(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -91,15 +94,15 @@ static void set_forward_delay(struct datapath *dp, unsigned long val)
 #endif
 }
 
-static ssize_t store_forward_delay(struct class_device *d,
+static ssize_t store_forward_delay(DEVICE_PARAMS,
 				   const char *buf, size_t len)
 {
-	return store_bridge_parm(d, buf, len, set_forward_delay);
+	return store_bridge_parm(DEVICE_ARGS, buf, len, set_forward_delay);
 }
 static BRC_DEVICE_ATTR(forward_delay, S_IRUGO | S_IWUSR,
 		   show_forward_delay, store_forward_delay);
 
-static ssize_t show_hello_time(struct class_device *d, char *buf)
+static ssize_t show_hello_time(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return sprintf(buf, "%lu\n",
@@ -121,17 +124,16 @@ static void set_hello_time(struct datapath *dp, unsigned long val)
 #endif
 }
 
-static ssize_t store_hello_time(struct class_device *d,
+static ssize_t store_hello_time(DEVICE_PARAMS,
 				const char *buf,
 				size_t len)
 {
-	return store_bridge_parm(d, buf, len, set_hello_time);
+	return store_bridge_parm(DEVICE_ARGS, buf, len, set_hello_time);
 }
 static BRC_DEVICE_ATTR(hello_time, S_IRUGO | S_IWUSR, show_hello_time,
 		   store_hello_time);
 
-static ssize_t show_max_age(struct class_device *d, 
-			    char *buf)
+static ssize_t show_max_age(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return sprintf(buf, "%lu\n",
@@ -153,15 +155,14 @@ static void set_max_age(struct datapath *dp, unsigned long val)
 #endif
 }
 
-static ssize_t store_max_age(struct class_device *d, 
+static ssize_t store_max_age(DEVICE_PARAMS,
 			     const char *buf, size_t len)
 {
-	return store_bridge_parm(d, buf, len, set_max_age);
+	return store_bridge_parm(DEVICE_ARGS, buf, len, set_max_age);
 }
 static BRC_DEVICE_ATTR(max_age, S_IRUGO | S_IWUSR, show_max_age, store_max_age);
 
-static ssize_t show_ageing_time(struct class_device *d,
-				char *buf)
+static ssize_t show_ageing_time(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -180,16 +181,15 @@ static void set_ageing_time(struct datapath *dp, unsigned long val)
 #endif
 }
 
-static ssize_t store_ageing_time(struct class_device *d,
+static ssize_t store_ageing_time(DEVICE_PARAMS,
 				 const char *buf, size_t len)
 {
-	return store_bridge_parm(d, buf, len, set_ageing_time);
+	return store_bridge_parm(DEVICE_ARGS, buf, len, set_ageing_time);
 }
 static BRC_DEVICE_ATTR(ageing_time, S_IRUGO | S_IWUSR, show_ageing_time,
 		   store_ageing_time);
 
-static ssize_t show_stp_state(struct class_device *d,
-			      char *buf)
+static ssize_t show_stp_state(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -200,7 +200,7 @@ static ssize_t show_stp_state(struct class_device *d,
 }
 
 
-static ssize_t store_stp_state(struct class_device *d,
+static ssize_t store_stp_state(DEVICE_PARAMS,
 			       const char *buf,
 			       size_t len)
 {
@@ -228,8 +228,7 @@ static ssize_t store_stp_state(struct class_device *d,
 static BRC_DEVICE_ATTR(stp_state, S_IRUGO | S_IWUSR, show_stp_state,
 		   store_stp_state);
 
-static ssize_t show_priority(struct class_device *d, 
-			     char *buf)
+static ssize_t show_priority(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -249,15 +248,14 @@ static void set_priority(struct datapath *dp, unsigned long val)
 #endif
 }
 
-static ssize_t store_priority(struct class_device *d, 
+static ssize_t store_priority(DEVICE_PARAMS,
 			       const char *buf, size_t len)
 {
-	return store_bridge_parm(d, buf, len, set_priority);
+	return store_bridge_parm(DEVICE_ARGS, buf, len, set_priority);
 }
 static BRC_DEVICE_ATTR(priority, S_IRUGO | S_IWUSR, show_priority, store_priority);
 
-static ssize_t show_root_id(struct class_device *d, 
-			    char *buf)
+static ssize_t show_root_id(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return br_show_bridge_id(buf, &to_bridge(d)->designated_root);
@@ -267,8 +265,7 @@ static ssize_t show_root_id(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(root_id, S_IRUGO, show_root_id, NULL);
 
-static ssize_t show_bridge_id(struct class_device *d, 
-			      char *buf)
+static ssize_t show_bridge_id(DEVICE_PARAMS, char *buf)
 {
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
 	const unsigned char *addr = dp->ports[ODPP_LOCAL]->dev->dev_addr;
@@ -279,8 +276,7 @@ static ssize_t show_bridge_id(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(bridge_id, S_IRUGO, show_bridge_id, NULL);
 
-static ssize_t show_root_port(struct class_device *d, 
-			      char *buf)
+static ssize_t show_root_port(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return sprintf(buf, "%d\n", to_bridge(d)->root_port);
@@ -290,8 +286,7 @@ static ssize_t show_root_port(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(root_port, S_IRUGO, show_root_port, NULL);
 
-static ssize_t show_root_path_cost(struct class_device *d,
-				   char *buf)
+static ssize_t show_root_path_cost(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return sprintf(buf, "%d\n", to_bridge(d)->root_path_cost);
@@ -301,8 +296,7 @@ static ssize_t show_root_path_cost(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(root_path_cost, S_IRUGO, show_root_path_cost, NULL);
 
-static ssize_t show_topology_change(struct class_device *d,
-				    char *buf)
+static ssize_t show_topology_change(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	return sprintf(buf, "%d\n", to_bridge(d)->topology_change);
@@ -312,8 +306,7 @@ static ssize_t show_topology_change(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(topology_change, S_IRUGO, show_topology_change, NULL);
 
-static ssize_t show_topology_change_detected(struct class_device *d,
-					     char *buf)
+static ssize_t show_topology_change_detected(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -325,8 +318,7 @@ static ssize_t show_topology_change_detected(struct class_device *d,
 static BRC_DEVICE_ATTR(topology_change_detected, S_IRUGO,
 		   show_topology_change_detected, NULL);
 
-static ssize_t show_hello_timer(struct class_device *d,
-				char *buf)
+static ssize_t show_hello_timer(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -337,8 +329,7 @@ static ssize_t show_hello_timer(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(hello_timer, S_IRUGO, show_hello_timer, NULL);
 
-static ssize_t show_tcn_timer(struct class_device *d, 
-			      char *buf)
+static ssize_t show_tcn_timer(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -349,8 +340,7 @@ static ssize_t show_tcn_timer(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(tcn_timer, S_IRUGO, show_tcn_timer, NULL);
 
-static ssize_t show_topology_change_timer(struct class_device *d,
-					  char *buf)
+static ssize_t show_topology_change_timer(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -362,8 +352,7 @@ static ssize_t show_topology_change_timer(struct class_device *d,
 static BRC_DEVICE_ATTR(topology_change_timer, S_IRUGO, show_topology_change_timer,
 		   NULL);
 
-static ssize_t show_gc_timer(struct class_device *d, 
-			     char *buf)
+static ssize_t show_gc_timer(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -374,8 +363,7 @@ static ssize_t show_gc_timer(struct class_device *d,
 }
 static BRC_DEVICE_ATTR(gc_timer, S_IRUGO, show_gc_timer, NULL);
 
-static ssize_t show_group_addr(struct class_device *d,
-			       char *buf)
+static ssize_t show_group_addr(DEVICE_PARAMS, char *buf)
 {
 #if 0
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -388,7 +376,7 @@ static ssize_t show_group_addr(struct class_device *d,
 #endif
 }
 
-static ssize_t store_group_addr(struct class_device *d,
+static ssize_t store_group_addr(DEVICE_PARAMS,
 				const char *buf, size_t len)
 {
 	struct datapath *dp = dp_dev_get_dp(to_net_dev(d));
@@ -431,23 +419,23 @@ static BRC_DEVICE_ATTR(group_addr, S_IRUGO | S_IWUSR,
 		   show_group_addr, store_group_addr);
 
 static struct attribute *bridge_attrs[] = {
-	&class_device_attr_forward_delay.attr,
-	&class_device_attr_hello_time.attr,
-	&class_device_attr_max_age.attr,
-	&class_device_attr_ageing_time.attr,
-	&class_device_attr_stp_state.attr,
-	&class_device_attr_priority.attr,
-	&class_device_attr_bridge_id.attr,
-	&class_device_attr_root_id.attr,
-	&class_device_attr_root_path_cost.attr,
-	&class_device_attr_root_port.attr,
-	&class_device_attr_topology_change.attr,
-	&class_device_attr_topology_change_detected.attr,
-	&class_device_attr_hello_timer.attr,
-	&class_device_attr_tcn_timer.attr,
-	&class_device_attr_topology_change_timer.attr,
-	&class_device_attr_gc_timer.attr,
-	&class_device_attr_group_addr.attr,
+	&DEV_ATTR(forward_delay).attr,
+	&DEV_ATTR(hello_time).attr,
+	&DEV_ATTR(max_age).attr,
+	&DEV_ATTR(ageing_time).attr,
+	&DEV_ATTR(stp_state).attr,
+	&DEV_ATTR(priority).attr,
+	&DEV_ATTR(bridge_id).attr,
+	&DEV_ATTR(root_id).attr,
+	&DEV_ATTR(root_path_cost).attr,
+	&DEV_ATTR(root_port).attr,
+	&DEV_ATTR(topology_change).attr,
+	&DEV_ATTR(topology_change_detected).attr,
+	&DEV_ATTR(hello_timer).attr,
+	&DEV_ATTR(tcn_timer).attr,
+	&DEV_ATTR(topology_change_timer).attr,
+	&DEV_ATTR(gc_timer).attr,
+	&DEV_ATTR(group_addr).attr,
 	NULL
 };
 
@@ -468,7 +456,7 @@ static struct attribute_group bridge_group = {
  */
 int brc_sysfs_add_dp(struct datapath *dp)
 {
-	struct kobject *kobj = to_kobj(dp->ports[ODPP_LOCAL]->dev);
+	struct kobject *kobj = &dp->ports[ODPP_LOCAL]->dev->NETDEV_DEV_MEMBER.kobj;
 	int err;
 
 	err = sysfs_create_group(kobj, &bridge_group);
@@ -487,12 +475,12 @@ int brc_sysfs_add_dp(struct datapath *dp)
 	err = kobject_register(&dp->ifobj);
 	if (err) {
 		pr_info("%s: can't add kobject (directory) %s/%s\n",
-				__FUNCTION__, dp_name(dp), dp->ifobj.name);
+			__FUNCTION__, dp_name(dp), kobject_name(&dp->ifobj));
 		goto out2;
 	}
 #else
-	br->ifobj = kobject_create_and_add(SYSFS_BRIDGE_PORT_SUBDIR, kobj);
-	if (!br->ifobj) {
+	dp->ifobj = kobject_create_and_add(SYSFS_BRIDGE_PORT_SUBDIR, kobj);
+	if (!dp->ifobj) {
 		pr_info("%s: can't add kobject (directory) %s/%s\n",
 			__func__, dp_name(dp), SYSFS_BRIDGE_PORT_SUBDIR);
 		goto out2;
@@ -508,7 +496,7 @@ int brc_sysfs_add_dp(struct datapath *dp)
 
 int brc_sysfs_del_dp(struct datapath *dp)
 {
-	struct kobject *kobj = to_kobj(dp->ports[ODPP_LOCAL]->dev);
+	struct kobject *kobj = &dp->ports[ODPP_LOCAL]->dev->NETDEV_DEV_MEMBER.kobj;
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 	kobject_unregister(&dp->ifobj);
@@ -519,7 +507,7 @@ int brc_sysfs_del_dp(struct datapath *dp)
 
 	return 0;
 }
-#else /* !SUPPORT_SYSFS */
+#else /* !CONFIG_SYSFS */
 int brc_sysfs_add_dp(struct datapath *dp) { return 0; }
 int brc_sysfs_del_dp(struct datapath *dp) { return 0; }
 int brc_sysfs_add_if(struct net_bridge_port *p) { return 0; }
@@ -529,4 +517,4 @@ int brc_sysfs_del_if(struct net_bridge_port *p)
 	kfree(p);
 	return 0;
 }
-#endif /* !SUPPORT_SYSFS */
+#endif /* !CONFIG_SYSFS */
diff --git a/datapath/brc_sysfs_if.c b/datapath/brc_sysfs_if.c
index 20bb109b..cd24c936 100644
--- a/datapath/brc_sysfs_if.c
+++ b/datapath/brc_sysfs_if.c
@@ -13,7 +13,7 @@
 #include "brc_sysfs.h"
 #include "datapath.h"
 
-#ifdef SUPPORT_SYSFS
+#ifdef CONFIG_SYSFS
 
 struct brport_attribute {
 	struct attribute	attr;
@@ -281,18 +281,14 @@ int brc_sysfs_add_if(struct net_bridge_port *p)
 	struct brport_attribute **a;
 	int err;
 
-	kobject_init(&p->kobj);
-	kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
-	p->kobj.ktype = &brport_ktype;
-	p->kobj.kset = NULL;
-	p->kobj.parent = &(p->dev->class_dev.kobj);
-
-	err = kobject_add(&p->kobj);
+	err = kobject_init_and_add(&p->kobj, &brport_ktype,
+				   &(p->dev->NETDEV_DEV_MEMBER.kobj),
+				   SYSFS_BRIDGE_PORT_ATTR);
 	if (err)
-		goto err_put;
+		goto err;
 
 	err = sysfs_create_link(&p->kobj,
-				&dp->ports[ODPP_LOCAL]->dev->class_dev.kobj,
+				&dp->ports[ODPP_LOCAL]->dev->NETDEV_DEV_MEMBER.kobj,
 				SYSFS_BRIDGE_PORT_LINK);
 	if (err)
 		goto err_del;
@@ -303,7 +299,11 @@ int brc_sysfs_add_if(struct net_bridge_port *p)
 			goto err_del;
 	}
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 	err = sysfs_create_link(&dp->ifobj, &p->kobj, p->dev->name);
+#else
+	err = sysfs_create_link(dp->ifobj, &p->kobj, p->dev->name);
+#endif
 	if (err)
 		goto err_del;
 
@@ -313,8 +313,8 @@ int brc_sysfs_add_if(struct net_bridge_port *p)
 
 err_del:
 	kobject_del(&p->kobj);
-err_put:
 	kobject_put(&p->kobj);
+err:
 	return err;
 }
 
@@ -331,4 +331,4 @@ int brc_sysfs_del_if(struct net_bridge_port *p)
 
 	return 0;
 }
-#endif /* SUPPORT_SYSFS */
+#endif /* CONFIG_SYSFS */
diff --git a/datapath/brcompat.c b/datapath/brcompat.c
index 2e437ccd..c4baac38 100644
--- a/datapath/brcompat.c
+++ b/datapath/brcompat.c
@@ -404,18 +404,14 @@ int brc_add_dp(struct datapath *dp)
 {
 	if (!try_module_get(THIS_MODULE))
 		return -ENODEV;
-#ifdef SUPPORT_SYSFS
 	brc_sysfs_add_dp(dp);
-#endif
 
 	return 0;
 }
 
 int brc_del_dp(struct datapath *dp) 
 {
-#ifdef SUPPORT_SYSFS
 	brc_sysfs_del_dp(dp);
-#endif
 	module_put(THIS_MODULE);
 
 	return 0;
@@ -450,10 +446,8 @@ __init brc_init(void)
 	dp_del_dp_hook = brc_del_dp;
 
 	/* Register hooks for interface adds and deletes */
-#ifdef SUPPORT_SYSFS
 	dp_add_if_hook = brc_sysfs_add_if;
 	dp_del_if_hook = brc_sysfs_del_if;
-#endif
 
 	/* Randomize the initial sequence number.  This is not a security
 	 * feature; it only helps avoid crossed wires between userspace and
diff --git a/datapath/datapath.c b/datapath/datapath.c
index f519809d..3233361c 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -421,10 +421,13 @@ int dp_del_port(struct net_bridge_port *p, struct list_head *dp_devs)
 {
 	ASSERT_RTNL();
 
-#ifdef SUPPORT_SYSFS
-	if (p->port_no != ODPP_LOCAL && dp_del_if_hook)
+	if (p->port_no != ODPP_LOCAL && dp_del_if_hook) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 		sysfs_remove_link(&p->dp->ifobj, p->dev->name);
+#else
+		sysfs_remove_link(p->dp->ifobj, p->dev->name);
 #endif
+	}
 	dp_ifinfo_notify(RTM_DELLINK, p);
 
 	p->dp->n_ports--;
diff --git a/datapath/datapath.h b/datapath/datapath.h
index 102b27f3..9332782d 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -10,6 +10,7 @@
 #include <linux/netdevice.h>
 #include <linux/workqueue.h>
 #include <linux/skbuff.h>
+#include <linux/version.h>
 #include "flow.h"
 #include "brc_sysfs.h"
 
@@ -58,8 +59,12 @@ struct datapath {
 	struct mutex mutex;
 	int dp_idx;
 
-#ifdef SUPPORT_SYSFS
+#ifdef CONFIG_SYSFS
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 	struct kobject ifobj;
+#else
+	struct kobject *ifobj;
+#endif
 #endif
 
 	int drop_frags;
@@ -88,7 +93,7 @@ struct net_bridge_port {
 	u16 port_no;
 	struct datapath	*dp;
 	struct net_device *dev;
-#ifdef SUPPORT_SYSFS
+#ifdef CONFIG_SYSFS
 	struct kobject kobj;
 #endif
 	struct list_head node;   /* Element in datapath.ports. */
diff --git a/datapath/linux-2.6/Modules.mk b/datapath/linux-2.6/Modules.mk
index bbc4c72f..e7359a46 100644
--- a/datapath/linux-2.6/Modules.mk
+++ b/datapath/linux-2.6/Modules.mk
@@ -12,6 +12,7 @@ openvswitch_headers += \
 	linux-2.6/compat-2.6/include/linux/ipv6.h \
 	linux-2.6/compat-2.6/include/linux/jiffies.h \
 	linux-2.6/compat-2.6/include/linux/kernel.h \
+	linux-2.6/compat-2.6/include/linux/kobject.h \
 	linux-2.6/compat-2.6/include/linux/log2.h \
 	linux-2.6/compat-2.6/include/linux/lockdep.h \
 	linux-2.6/compat-2.6/include/linux/mutex.h \
diff --git a/datapath/linux-2.6/compat-2.6/include/linux/kobject.h b/datapath/linux-2.6/compat-2.6/include/linux/kobject.h
new file mode 100644
index 00000000..7dbb010c
--- /dev/null
+++ b/datapath/linux-2.6/compat-2.6/include/linux/kobject.h
@@ -0,0 +1,23 @@
+#ifndef __LINUX_KOBJECT_WRAPPER_H
+#define __LINUX_KOBJECT_WRAPPER_H 1
+
+#include_next <linux/kobject.h>
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
+static inline int kobject_init_and_add(struct kobject *kobj,
+					struct kobj_type *ktype,
+					struct kobject *parent,
+					const char *name)
+{
+	kobject_init(kobj);
+	kobject_set_name(kobj, "%s", name);
+	kobj->ktype = ktype;
+	kobj->kset = NULL;
+	kobj->parent = parent;
+
+	return kobject_add(kobj);
+}
+#endif
+
+#endif /* linux/kobject.h wrapper */
diff --git a/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h b/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
index 32e1735d..d2915133 100644
--- a/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
+++ b/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
@@ -5,8 +5,19 @@
 
 struct net;
 
+/* Before 2.6.21, struct net_device has a "struct class_device" member named
+ * class_dev.  Beginning with 2.6.21, struct net_device instead has a "struct
+ * device" member named dev.  Otherwise the usage of these members is pretty
+ * much the same. */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)
+#define NETDEV_DEV_MEMBER class_dev
+#else
+#define NETDEV_DEV_MEMBER dev
+#endif
+
 #ifndef to_net_dev
-#define to_net_dev(class) container_of(class, struct net_device, class_dev)
+#define to_net_dev(class) \
+	container_of(class, struct net_device, NETDEV_DEV_MEMBER)
 #endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,26)