netns: sysfs: add a netns suffix to net device sysfs entries

---
 include/net/net_namespace.h |    2 ++
 net/core/net_namespace.c    |   24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

include/net/net_namespace.h +2 -0

Index: net-next-2.6/include/net/net_namespace.h
===================================================================
@@ -75,6 +75,8 @@ struct net {
 #endif
 #endif
 	struct net_generic	*gen;
+
+	int			id;
 };

net/core/net_namespace.c +24 -0

Index: net-next-2.6/net/core/net_namespace.c
===================================================================
@@ -26,6 +26,16 @@ EXPORT_SYMBOL(init_net);
 #define INITIAL_NET_GEN_PTRS	13 /* +1 for len +2 for rcu_head */
 
 /*
+ * IDs allocated from this ida are used as a suffix in sysfs to tag
+ * devices belonging to each netns (other than init_net).
+ * Only 4 characters are left to store a separator plus this tag in sysfs
+ * (BUS_ID_SIZE-IFNAMSIZ)
+ * Thus, this limits us to 4095 ("FFF") simultaneous network namespaces.
+ */
+static DEFINE_IDA(net_id_ida);
+#define NET_ID_MAX 0xFFF
+
+/*
  * setup_net runs the initializers for the network namespace object.
  */
 static __net_init int setup_net(struct net *net)

@@ -40,7 +50,20 @@ static __net_init int setup_net(struct n
 	atomic_set(&net->use_count, 0);
 #endif
 
+	/* Get an ID */
+again:
+	error = ida_get_new(&net_id_ida, &net->id);
+	if (error) {
+		if (error == -EAGAIN) {
+			ida_pre_get(&net_id_ida, GFP_KERNEL);
+			goto again;
+		}
+		goto out;
+	}
 	error = -ENOMEM;
+	if (net->id > NET_ID_MAX)
+		goto out;
+
 	ng = kzalloc(sizeof(struct net_generic) +
 			INITIAL_NET_GEN_PTRS * sizeof(void *), GFP_KERNEL);
 	if (ng == NULL)

@@ -97,6 +120,7 @@ static void net_free(struct net *net)
 	}
 #endif
 
+	ida_remove(&net_id_ida, net->id);
 	kmem_cache_free(net_cachep, net);
 }

Benjamin Thery

2008-10-22 15:22 UTC #2 lore raw

PATCH 2/4 netns: Export nets id to /proc/net/netns

This patches exports the new 'struct net' net->id value to /proc/net/nsid file.

Signed-off-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>

---
 net/core/net_namespace.c |   50 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

net/core/net_namespace.c +50 -0

Index: net-next-2.6/net/core/net_namespace.c
===================================================================
@@ -6,6 +6,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/idr.h>
+#include <linux/proc_fs.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>

@@ -211,6 +212,53 @@ struct net *copy_net_ns(unsigned long fl
 }
 #endif
 
+#ifdef CONFIG_PROC_FS
+static int netns_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq->private;
+
+	seq_printf(seq, "%x\n", net->id);
+	return 0;
+}
+
+static int netns_seq_open(struct inode *inode, struct file *file)
+{
+        return single_open_net(inode, file, netns_seq_show);
+}
+
+static const struct file_operations netns_seq_fops = {
+	.owner   = THIS_MODULE,
+	.open    = netns_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release_net,
+};
+
+static int __net_init netns_net_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "nsid", S_IRUGO, &netns_seq_fops))
+		return -ENOMEM;
+	return 0;
+}
+
+static void __net_exit netns_net_exit(struct net *net)
+{
+	proc_net_remove(net, "nsid");
+}
+
+static struct pernet_operations netns_proc_ops = {
+	.init = netns_net_init,
+	.exit = netns_net_exit,
+};
+
+static int __init netns_proc_init()
+{
+	return register_pernet_subsys(&netns_proc_ops);
+}
+#else
+#define netns_proc_init() 0
+#endif /* CONFIG_PROC_FS */
+
 static int __init net_ns_init(void)
 {
 	int err;

@@ -226,6 +274,8 @@ static int __init net_ns_init(void)
 	if (!netns_wq)
 		panic("Could not create netns workq");
 #endif
+	if (netns_proc_init())
+		panic("Could not register netns subsys");
 
 	mutex_lock(&net_mutex);
 	err = setup_net(&init_net);

Benjamin Thery

author

2008-10-22 15:23 UTC #3 lore raw

PATCH 1/4 netns: add in ida ID to identify the network namespace

This patch adds in 'id' member to struct net. This member contains an IDA ID. The id is allocated at netns creation.

---
 include/net/net_namespace.h |    2 ++
 net/core/net_namespace.c    |   24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

include/net/net_namespace.h +2 -0

Index: net-next-2.6/include/net/net_namespace.h
===================================================================
@@ -75,6 +75,8 @@ struct net {
 #endif
 #endif
 	struct net_generic	*gen;
+
+	int			id;
 };

net/core/net_namespace.c +24 -0

Index: net-next-2.6/net/core/net_namespace.c
===================================================================
@@ -26,6 +26,16 @@ EXPORT_SYMBOL(init_net);
 #define INITIAL_NET_GEN_PTRS	13 /* +1 for len +2 for rcu_head */
 
 /*
+ * IDs allocated from this ida are used as a suffix in sysfs to tag
+ * devices belonging to each netns (other than init_net).
+ * Only 4 characters are left to store a separator plus this tag in sysfs
+ * (BUS_ID_SIZE-IFNAMSIZ)
+ * Thus, this limits us to 4095 ("FFF") simultaneous network namespaces.
+ */
+static DEFINE_IDA(net_id_ida);
+#define NET_ID_MAX 0xFFF
+
+/*
  * setup_net runs the initializers for the network namespace object.
  */
 static __net_init int setup_net(struct net *net)

@@ -40,7 +50,20 @@ static __net_init int setup_net(struct n
 	atomic_set(&net->use_count, 0);
 #endif
 
+	/* Get an ID */
+again:
+	error = ida_get_new(&net_id_ida, &net->id);
+	if (error) {
+		if (error == -EAGAIN) {
+			ida_pre_get(&net_id_ida, GFP_KERNEL);
+			goto again;
+		}
+		goto out;
+	}
 	error = -ENOMEM;
+	if (net->id > NET_ID_MAX)
+		goto out;
+
 	ng = kzalloc(sizeof(struct net_generic) +
 			INITIAL_NET_GEN_PTRS * sizeof(void *), GFP_KERNEL);
 	if (ng == NULL)

@@ -97,6 +120,7 @@ static void net_free(struct net *net)
 	}
 #endif
 
+	ida_remove(&net_id_ida, net->id);
 	kmem_cache_free(net_cachep, net);
 }

Benjamin Thery

2008-10-22 15:22 UTC #4 lore raw

PATCH 3/4 net: cleanup some vars names to be more consistant with the network code

This small patch renames a couple of net_device variables from 'net' to 'netdev' to avoid confusion with 'struct net' variables that will be introduced in the next patch.
'net' is commonly used to designate 'struct net' in the rest of the network code.

Signed-off-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>

---
 net/core/net-sysfs.c |   17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

net/core/net-sysfs.c +9 -8

Index: net-next-2.6/net/core/net-sysfs.c
===================================================================
@@ -471,32 +471,33 @@ static struct class net_class = {
 /* Delete sysfs entries but hold kobject reference until after all
  * netdev references are gone.
  */
-void netdev_unregister_kobject(struct net_device * net)
+void netdev_unregister_kobject(struct net_device *netdev)
 {
-	struct device *dev = &(net->dev);
+	struct device *dev = &(netdev->dev);
 
 	kobject_get(&dev->kobj);
 	device_del(dev);
 }
 
 /* Create sysfs entries for network device. */
-int netdev_register_kobject(struct net_device *net)
+int netdev_register_kobject(struct net_device *netdev)
 {
-	struct device *dev = &(net->dev);
-	struct attribute_group **groups = net->sysfs_groups;
+	struct device *dev = &(netdev->dev);
+	struct attribute_group **groups = netdev->sysfs_groups;
 
 	dev->class = &net_class;
-	dev->platform_data = net;
+	dev->platform_data = netdev;
 	dev->groups = groups;
 
 	BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ);
-	strlcpy(dev->bus_id, net->name, BUS_ID_SIZE);
+	strlcpy(dev->bus_id, netdev->name, BUS_ID_SIZE);
 
 #ifdef CONFIG_SYSFS
 	*groups++ = &netstat_group;
 
 #ifdef CONFIG_WIRELESS_EXT_SYSFS
-	if (net->wireless_handlers && net->wireless_handlers->get_wireless_stats)
+	if (netdev->wireless_handlers &&
+	    netdev->wireless_handlers->get_wireless_stats)
 		*groups++ = &wireless_group;
 #endif
 #endif /* CONFIG_SYSFS */

Benjamin Thery

2008-10-22 15:22 UTC #5 lore raw

PATCH 4/4 netns: sysfs: add netns suffix to net devices sysfs entries

Reminder: what we want is being able to create network interfaces with the same name in different network namespaces (eg. the loopback). The remaining issues are in sysfs.

This patch dissociates network devices actual names (stored in struct net_device and seen by ifconfig/ip tools) and network device names stored in sysfs.

When adding a network device in child net namespace (!init_net), when registering it in sysfs, a suffix unique to the current netns is appended to the actual device name. Currently this suffix is the netns ida ID in hexa form separated by a '@' char.

In sysfs, we see all the network devices of all netns.

# ll /sys/devices/virtual/net/
...
drwxr-xr-x 4 root root 0 2008-10-13 14:08 lo
drwxr-xr-x 4 root root 0 2008-10-13 16:31 lo@1
...
drwxr-xr-x 4 root root 0 2008-10-13 16:31 lo@e5
...

Then, in the child network namespace we can filter the contents of /sys/class/net with:

* mount -t tmpfs /sys/class/net
* and manually link the right devices from /sys/devices/virtual/net (ln -s ../../devices/virtual/net/lo@1 lo)

Thus, /sys/class/net appears to be fine for the applications running in this namespace.

FUSE can also be used to alter the view of /sys/class/net in the namespace.

Issues:
-------

* The suffix

We only have four characters left (BUS_ID_SIZE - IFNAMSIZ) to build the
suffix: add a separator and encode the netns ID.
By encoding the ID in hexa, it introduces a limit of 4095 (0xFFF) sub-network namespaces running at the same time.

* This approach reduces isolation between network namespaces

Everyone can see all the devices in each namespaces by exploring /sys/devices/../.. or /sys/class/net (if it's not re-mounted as tmpfs).

* Does not work very well with CONFIG_SYSFS_DEPRECATED=y

The filtering of /sys/class/net with CONFIG_SYSFS_DEPRECATED=y is more difficult to do because in this case /sys/class/net contains the actual directories (not symlinks).

Signed-off-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>

Tested-by Serge Hallyn <serue-r/[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |    4 +++-
 net/core/net-sysfs.c |   34 +++++++++++++++++++++++++++++++++-
 net/core/net-sysfs.h |    1 +
 4 files changed, 38 insertions(+), 3 deletions(-)

net/Kconfig +1 -1

Index: net-next-2.6/net/Kconfig
===================================================================
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +3 -1

Index: net-next-2.6/net/core/dev.c
===================================================================
@@ -894,6 +894,7 @@ int dev_alloc_name(struct net_device *de
 int dev_change_name(struct net_device *dev, const char *newname)
 {
 	char oldname[IFNAMSIZ];
+	char devname[BUS_ID_SIZE];
 	int err = 0;
 	int ret;
 	struct net *net;

@@ -924,7 +925,8 @@ int dev_change_name(struct net_device *d
 		strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-	err = device_rename(&dev->dev, dev->name);
+	netdev_fill_bus_id_name(devname, dev);
+	err = device_rename(&dev->dev, devname);
 	if (err) {
 		memcpy(dev->name, oldname, IFNAMSIZ);
 		return err;

net/core/net-sysfs.c +33 -1

Index: net-next-2.6/net/core/net-sysfs.c
===================================================================
@@ -468,6 +468,38 @@ static struct class net_class = {
 #endif
 };
 
+/* Fill device bus_id name from net device name
+ * When registering a device for a child network namespace,
+ * a suffix is added to the name stored in "struct device"
+ * bus_id.
+ *
+ * devname size must be at least BUS_ID_SIZE
+ */
+void netdev_fill_bus_id_name(char *devname, struct net_device *netdev)
+{
+#ifndef CONFIG_NET_NS
+	strlcpy(devname, netdev->name, BUS_ID_SIZE);
+#else
+	struct net *net = dev_net(netdev);
+
+	if (net_eq(net, &init_net))
+		strlcpy(devname, netdev->name, BUS_ID_SIZE);
+	else {
+		/*
+		 * To allow registration of net devices with the same name in
+		 * different namespaces, append the netns identifier to the
+		 * device name in sysfs using the 4 bytes left in bus_id
+		 * (BUS_ID_SIZE - IFNAMSIZ).
+		 *
+		 * devname is in the form: device_name@XXX
+		 * the netns identifier is an integer < 4095, thus encodable
+		 * in hexa in 3 characters ("FFF").
+		 */
+		snprintf(devname, BUS_ID_SIZE, "%s@%x", netdev->name, net->id);
+	}
+#endif
+}
+
 /* Delete sysfs entries but hold kobject reference until after all
  * netdev references are gone.
  */

@@ -490,7 +522,7 @@ int netdev_register_kobject(struct net_d
 	dev->groups = groups;
 
 	BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ);
-	strlcpy(dev->bus_id, netdev->name, BUS_ID_SIZE);
+	netdev_fill_bus_id_name(dev->bus_id, netdev);
 
 #ifdef CONFIG_SYSFS
 	*groups++ = &netstat_group;

net/core/net-sysfs.h +1 -0

Index: net-next-2.6/net/core/net-sysfs.h
===================================================================
@@ -5,4 +5,5 @@ int netdev_kobject_init(void);
 int netdev_register_kobject(struct net_device *);
 void netdev_unregister_kobject(struct net_device *);
 void netdev_initialize_kobject(struct net_device *);
+void netdev_fill_bus_id_name(char *, struct net_device *);
 #endif

Benjamin Thery

author

2008-10-22 15:23 UTC #6 lore raw

PATCH 2/4 netns: Export nets id to /proc/net/netns

This patches exports the new 'struct net' net->id value to /proc/net/nsid file.

---
 net/core/net_namespace.c |   50 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

net/core/net_namespace.c +50 -0

Index: net-next-2.6/net/core/net_namespace.c
===================================================================
@@ -6,6 +6,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/idr.h>
+#include <linux/proc_fs.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>

@@ -211,6 +212,53 @@ struct net *copy_net_ns(unsigned long fl
 }
 #endif
 
+#ifdef CONFIG_PROC_FS
+static int netns_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq->private;
+
+	seq_printf(seq, "%x\n", net->id);
+	return 0;
+}
+
+static int netns_seq_open(struct inode *inode, struct file *file)
+{
+        return single_open_net(inode, file, netns_seq_show);
+}
+
+static const struct file_operations netns_seq_fops = {
+	.owner   = THIS_MODULE,
+	.open    = netns_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release_net,
+};
+
+static int __net_init netns_net_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "nsid", S_IRUGO, &netns_seq_fops))
+		return -ENOMEM;
+	return 0;
+}
+
+static void __net_exit netns_net_exit(struct net *net)
+{
+	proc_net_remove(net, "nsid");
+}
+
+static struct pernet_operations netns_proc_ops = {
+	.init = netns_net_init,
+	.exit = netns_net_exit,
+};
+
+static int __init netns_proc_init()
+{
+	return register_pernet_subsys(&netns_proc_ops);
+}
+#else
+#define netns_proc_init() 0
+#endif /* CONFIG_PROC_FS */
+
 static int __init net_ns_init(void)
 {
 	int err;

@@ -226,6 +274,8 @@ static int __init net_ns_init(void)
 	if (!netns_wq)
 		panic("Could not create netns workq");
 #endif
+	if (netns_proc_init())
+		panic("Could not register netns subsys");
 
 	mutex_lock(&net_mutex);
 	err = setup_net(&init_net);

Benjamin Thery

author

2008-10-22 15:22 UTC #7 lore raw

PATCH 3/4 net: cleanup some vars names to be more consistant with the network code

---
 net/core/net-sysfs.c |   17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

net/core/net-sysfs.c +9 -8

Index: net-next-2.6/net/core/net-sysfs.c
===================================================================
@@ -471,32 +471,33 @@ static struct class net_class = {
 /* Delete sysfs entries but hold kobject reference until after all
  * netdev references are gone.
  */
-void netdev_unregister_kobject(struct net_device * net)
+void netdev_unregister_kobject(struct net_device *netdev)
 {
-	struct device *dev = &(net->dev);
+	struct device *dev = &(netdev->dev);
 
 	kobject_get(&dev->kobj);
 	device_del(dev);
 }
 
 /* Create sysfs entries for network device. */
-int netdev_register_kobject(struct net_device *net)
+int netdev_register_kobject(struct net_device *netdev)
 {
-	struct device *dev = &(net->dev);
-	struct attribute_group **groups = net->sysfs_groups;
+	struct device *dev = &(netdev->dev);
+	struct attribute_group **groups = netdev->sysfs_groups;
 
 	dev->class = &net_class;
-	dev->platform_data = net;
+	dev->platform_data = netdev;
 	dev->groups = groups;
 
 	BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ);
-	strlcpy(dev->bus_id, net->name, BUS_ID_SIZE);
+	strlcpy(dev->bus_id, netdev->name, BUS_ID_SIZE);
 
 #ifdef CONFIG_SYSFS
 	*groups++ = &netstat_group;
 
 #ifdef CONFIG_WIRELESS_EXT_SYSFS
-	if (net->wireless_handlers && net->wireless_handlers->get_wireless_stats)
+	if (netdev->wireless_handlers &&
+	    netdev->wireless_handlers->get_wireless_stats)
 		*groups++ = &wireless_group;
 #endif
 #endif /* CONFIG_SYSFS */

Benjamin Thery

author

2008-10-22 15:23 UTC #8 lore raw

PATCH 4/4 netns: sysfs: add netns suffix to net devices sysfs entries

Reminder: what we want is being able to create network interfaces with the same name in different network namespaces (eg. the loopback). The remaining issues are in sysfs.

This patch dissociates network devices actual names (stored in struct net_device and seen by ifconfig/ip tools) and network device names stored in sysfs.

In sysfs, we see all the network devices of all netns.

# ll /sys/devices/virtual/net/
...
drwxr-xr-x 4 root root 0 2008-10-13 14:08 lo
drwxr-xr-x 4 root root 0 2008-10-13 16:31 lo@1
...
drwxr-xr-x 4 root root 0 2008-10-13 16:31 lo@e5
...

Then, in the child network namespace we can filter the contents of /sys/class/net with:

* mount -t tmpfs /sys/class/net
* and manually link the right devices from /sys/devices/virtual/net (ln -s ../../devices/virtual/net/lo@1 lo)

Thus, /sys/class/net appears to be fine for the applications running in this namespace.

FUSE can also be used to alter the view of /sys/class/net in the namespace.

Issues:
-------

* The suffix

* This approach reduces isolation between network namespaces

Everyone can see all the devices in each namespaces by exploring /sys/devices/../.. or /sys/class/net (if it's not re-mounted as tmpfs).

* Does not work very well with CONFIG_SYSFS_DEPRECATED=y

The filtering of /sys/class/net with CONFIG_SYSFS_DEPRECATED=y is more difficult to do because in this case /sys/class/net contains the actual directories (not symlinks).

Tested-by Serge Hallyn <[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |    4 +++-
 net/core/net-sysfs.c |   34 +++++++++++++++++++++++++++++++++-
 net/core/net-sysfs.h |    1 +
 4 files changed, 38 insertions(+), 3 deletions(-)

net/Kconfig +1 -1

Index: net-next-2.6/net/Kconfig
===================================================================
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +3 -1

Index: net-next-2.6/net/core/dev.c
===================================================================
@@ -894,6 +894,7 @@ int dev_alloc_name(struct net_device *de
 int dev_change_name(struct net_device *dev, const char *newname)
 {
 	char oldname[IFNAMSIZ];
+	char devname[BUS_ID_SIZE];
 	int err = 0;
 	int ret;
 	struct net *net;

@@ -924,7 +925,8 @@ int dev_change_name(struct net_device *d
 		strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-	err = device_rename(&dev->dev, dev->name);
+	netdev_fill_bus_id_name(devname, dev);
+	err = device_rename(&dev->dev, devname);
 	if (err) {
 		memcpy(dev->name, oldname, IFNAMSIZ);
 		return err;

net/core/net-sysfs.c +33 -1

Index: net-next-2.6/net/core/net-sysfs.c
===================================================================
@@ -468,6 +468,38 @@ static struct class net_class = {
 #endif
 };
 
+/* Fill device bus_id name from net device name
+ * When registering a device for a child network namespace,
+ * a suffix is added to the name stored in "struct device"
+ * bus_id.
+ *
+ * devname size must be at least BUS_ID_SIZE
+ */
+void netdev_fill_bus_id_name(char *devname, struct net_device *netdev)
+{
+#ifndef CONFIG_NET_NS
+	strlcpy(devname, netdev->name, BUS_ID_SIZE);
+#else
+	struct net *net = dev_net(netdev);
+
+	if (net_eq(net, &init_net))
+		strlcpy(devname, netdev->name, BUS_ID_SIZE);
+	else {
+		/*
+		 * To allow registration of net devices with the same name in
+		 * different namespaces, append the netns identifier to the
+		 * device name in sysfs using the 4 bytes left in bus_id
+		 * (BUS_ID_SIZE - IFNAMSIZ).
+		 *
+		 * devname is in the form: device_name@XXX
+		 * the netns identifier is an integer < 4095, thus encodable
+		 * in hexa in 3 characters ("FFF").
+		 */
+		snprintf(devname, BUS_ID_SIZE, "%s@%x", netdev->name, net->id);
+	}
+#endif
+}
+
 /* Delete sysfs entries but hold kobject reference until after all
  * netdev references are gone.
  */

@@ -490,7 +522,7 @@ int netdev_register_kobject(struct net_d
 	dev->groups = groups;
 
 	BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ);
-	strlcpy(dev->bus_id, netdev->name, BUS_ID_SIZE);
+	netdev_fill_bus_id_name(dev->bus_id, netdev);
 
 #ifdef CONFIG_SYSFS
 	*groups++ = &netstat_group;

net/core/net-sysfs.h +1 -0

Index: net-next-2.6/net/core/net-sysfs.h
===================================================================
@@ -5,4 +5,5 @@ int netdev_kobject_init(void);
 int netdev_register_kobject(struct net_device *);
 void netdev_unregister_kobject(struct net_device *);
 void netdev_initialize_kobject(struct net_device *);
+void netdev_fill_bus_id_name(char *, struct net_device *);
 #endif

A message that is not in the archive (sent off-list or not yet received): 20081022152144.351965414-4vkkeT0zb4ZEtYaxpPmRp1aPQRlvutdw@public.gmane.org

Eric W. Biederman

2008-10-22 19:59 UTC #10 lore raw

Quoted 3 lines · Benjamin Thery

Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.

Ben your patchset is completely inappropriate.

Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.

Eric

Greg KH

2008-10-22 20:16 UTC #11 lore raw

Quoted 3 lines · Benjamin Thery

Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e

How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?

thanks,

greg k-h

Eric W. Biederman

2008-10-22 20:32 UTC #12 lore raw

PATCH 1/1 netns: Coexist with the sysfs limitations

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.

Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.

Plus no ABIs are harmed with this patch.

Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   12 +++++++++++-
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +11 -1

index b8a4fd0..a7f0461 100644
@@ -4449,6 +4449,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4515,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4533,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 1 line

1.5.3.rc6.17.g1911

Eric W. Biederman

2008-10-22 20:04 UTC #13 lore raw

Quoted 3 lines · Benjamin Thery

Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.

Ben your patchset is completely inappropriate.

Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.

Eric

A message that is not in the archive (sent off-list or not yet received): [email protected]

Serge E. Hallyn

2008-10-22 20:30 UTC #15 lore raw

Quoted 6 lines · Eric W. Biederman

Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.

Quoted 7 lines

Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.

I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

	mount -t tmpfs none /sys/class/net
	mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo

if they really want to, in which case only their view of /sys/devices/virtual/net would be different.

Eric, would you hate this less if it was under some

CONFIG_SYSFS_NETNS_HACK

config variable?

-serge

Benjamin Thery

2008-10-23 11:56 UTC #16 lore raw

Quoted 10 lines · Eric W. Biederman

Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

In fact, I feared that would be an issue before I sent the patches. Thanks for confirming this.

But, as this alternative was discussed a bit after Al's comments on your last patches, I had to give it a try and code a proof-of-concept.

Benjamin

Quoted 8 lines

That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
Eric

Signature · 3 lines

B e n j a m i n   T h e r y  - BULL/DT/Open Software R&D

    http://www.bull.com

Serge E. Hallyn

2008-10-22 20:30 UTC #17 lore raw

In reply to Serge E. Hallyn

Quoted 6 lines · Eric W. Biederman

Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.

Quoted 7 lines

Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.

I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

	mount -t tmpfs none /sys/class/net
	mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo

if they really want to, in which case only their view of /sys/devices/virtual/net would be different.

Eric, would you hate this less if it was under some

CONFIG_SYSFS_NETNS_HACK

config variable?

-serge

A message that is not in the archive (sent off-list or not yet received): 20081022203045.GA4633-r/[email protected]

Eric W. Biederman

2008-10-22 21:01 UTC #19 lore raw

Quoted 12 lines · Serge E. Hallyn

Quoted 11 lines · Eric W. Biederman
Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

Quoted 6 lines

Quoted 2 lines
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.

Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.

Quoted 4 lines

	mount -t tmpfs none /sys/class/net
	mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo

Quoted 8 lines

if they really want to, in which case only their view of /sys/devices/virtual/net would be different.
Eric, would you hate this less if it was under some
CONFIG_SYSFS_NETNS_HACK
config variable?

No. ABI decisions are almost certainly irreversible.

If we need an immediate hack please see the patch I sent in follow up. We can achieve everything Ben is doing by simply keeping virtual devices out of the kobject tree. Keeping them from showing up in sysfs.

Eric

Eric W. Biederman

2008-10-22 21:04 UTC #20 lore raw

Quoted 12 lines · Serge E. Hallyn

Quoted 11 lines · Eric W. Biederman
Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

Quoted 6 lines

Quoted 2 lines
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.

Quoted 4 lines

	mount -t tmpfs none /sys/class/net
	mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo

Quoted 8 lines

if they really want to, in which case only their view of /sys/devices/virtual/net would be different.
Eric, would you hate this less if it was under some
CONFIG_SYSFS_NETNS_HACK
config variable?

No. ABI decisions are almost certainly irreversible.

Eric

A message that is not in the archive (sent off-list or not yet received): [email protected]

Stephen Hemminger

2008-10-22 21:55 UTC #22 lore raw

Quoted 21 lines · On Wed, 22 Oct 2008 14:01:59 -0700 ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]…

Quoted 12 lines · Serge E. Hallyn
Quoted 11 lines · Eric W. Biederman
Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.
Quoted 6 lines
Quoted 2 lines
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

Quoted 8 lines

The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.

Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip

Stephen Hemminger

2008-10-22 21:55 UTC #23 lore raw

In reply to Stephen Hemminger

Quoted 21 lines · On Wed, 22 Oct 2008 14:01:59 -0700 [email protected] (Eric W. Biederman)…

Quoted 12 lines · Serge E. Hallyn
Quoted 11 lines · Eric W. Biederman
Quoted 3 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.
Quoted 6 lines
Quoted 2 lines
That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
I disagree (not surprising :) completely. The well-known userspace tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. Userspace in a container can either umount /sys completely, or do

Quoted 8 lines

The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.

Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip

Eric W. Biederman

2008-10-22 22:54 UTC #24 lore raw

Quoted 11 lines · Stephen Hemminger

Quoted 8 lines
The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.
Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip

Yes. So we need the correct values in /sys/class/net.

Which is why sysfs and network namespaces do not coexist currently.

Which is why I recommend only placing devices in the initial network namespace in sysfs for the short term.

Which is why we need to get all of the details correct when we handle multiple network namespaces and sysfs.

I should have something working and should be sending patches out shortly. Cleaning up sysfs and the device model enough so the changes are not spooky is a long hard road unfortunately.

Eric

Eric W. Biederman

2008-10-22 23:04 UTC #25 lore raw

Quoted 11 lines · Stephen Hemminger

Quoted 8 lines
The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.
Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip

Yes. So we need the correct values in /sys/class/net.

Which is why sysfs and network namespaces do not coexist currently.

Which is why I recommend only placing devices in the initial network namespace in sysfs for the short term.

Which is why we need to get all of the details correct when we handle multiple network namespaces and sysfs.

I should have something working and should be sending patches out shortly. Cleaning up sysfs and the device model enough so the changes are not spooky is a long hard road unfortunately.

Eric

A message that is not in the archive (sent off-list or not yet received): [email protected]

Kyle Moffett

2008-10-23 04:14 UTC #27 lore raw

Quoted 10 lines · Eric W. Biederman

Quoted 9 lines · Stephen Hemminger
Quoted 8 lines
The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.

Quoted 6 lines

Quoted 2 lines
Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip
Yes. So we need the correct values in /sys/class/net.
Which is why sysfs and network namespaces do not coexist currently.

I definitely agree that "eth0@1" is a bad ide. I know for sure that a relatively large number of system init scripts poke about in /sys/class/net/$IFACE, as well as a number of the system installation scripts. Those scripts include some that my company has written for internal use and others supplied by distributions.

Daemons and such mostly use netlink, but for anything written in shell it's much easier to do things like this:

for devpath in /sys/class/net/*; do

    dev="${dev##/sys/class/net/}"
    case "${dev}" in
        [....]
    esac
    if [ "x${mac}" = "x$(cat ${devpath}/address)" ]; then
        echo "Found MAC '${mac}': ${dev}"
    fi

done

If I wanted to perform similar things with the output of ifconfig, it would involve some much more fragile manual text parsing of the output of the "ip" or "ifconfig" commands. And sometimes the "ifconfig" command is outright wrong. If you have an interface name longer than 7 characters or so then some versions of ifconfig will truncate it internally and display garbage.

While the "show only the root namespace" interim solution is problematic for processes in network namespaces, I think it's more important not to break things for admin tools in the root namespace.

Cheers,
Kyle Moffett

Kyle Moffett

2008-10-23 04:14 UTC #28 lore raw

Quoted 10 lines · Eric W. Biederman

Quoted 9 lines · Stephen Hemminger
Quoted 8 lines
The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.

Quoted 6 lines

Quoted 2 lines
Lots of scripts are starting use /sys for things. It is easier to parse /sys/class/net than the output of ifconfig or ip
Yes. So we need the correct values in /sys/class/net.
Which is why sysfs and network namespaces do not coexist currently.

Daemons and such mostly use netlink, but for anything written in shell it's much easier to do things like this:

for devpath in /sys/class/net/*; do

    dev="${dev##/sys/class/net/}"
    case "${dev}" in
        [....]
    esac
    if [ "x${mac}" = "x$(cat ${devpath}/address)" ]; then
        echo "Found MAC '${mac}': ${dev}"
    fi

done

While the "show only the root namespace" interim solution is problematic for processes in network namespaces, I think it's more important not to break things for admin tools in the root namespace.

Cheers,
Kyle Moffett

Benjamin Thery

author

2008-10-23 12:00 UTC #29 lore raw

Quoted 9 lines · Eric W. Biederman

Quoted 2 lines · Benjamin Thery
Support for network namespaces in mainline is pretty complete for
some time now, but there is still this issue with sysfs that prevents more people to use it easily.
Ben your patchset is completely inappropriate.
Temporarily adding elements to the ABI that we intend to remove is not a proper solution to this problem.

In fact, I feared that would be an issue before I sent the patches. Thanks for confirming this.

But, as this alternative was discussed a bit after Al's comments on your last patches, I had to give it a try and code a proof-of-concept.

Benjamin

Quoted 8 lines

That user space visible ida you add is a namespace identifier that breaks nested containers and migration. It is very very very wrong.
Eric

Signature · 3 lines

B e n j a m i n   T h e r y  - BULL/DT/Open Software R&D

   http://www.bull.com

A message that is not in the archive (sent off-list or not yet received): 49006671.3010804-6ktuUTfB/[email protected]

Eric W. Biederman

2008-10-23 15:46 UTC #31 lore raw

Quoted 5 lines · Benjamin Thery

In fact, I feared that would be an issue before I sent the patches. Thanks for confirming this.
But, as this alternative was discussed a bit after Al's comments on your last patches, I had to give it a try and code a proof-of-concept.

Yes. We have a lot of reasons now for why that approach is a bad idea. Which should help a lot when it comes to handling sysfs properly.

Eric

Eric W. Biederman

2008-10-23 15:54 UTC #32 lore raw

Quoted 5 lines · Benjamin Thery

In fact, I feared that would be an issue before I sent the patches. Thanks for confirming this.
But, as this alternative was discussed a bit after Al's comments on your last patches, I had to give it a try and code a proof-of-concept.

Yes. We have a lot of reasons now for why that approach is a bad idea. Which should help a lot when it comes to handling sysfs properly.

Eric

Greg KH

2008-10-22 20:20 UTC #33 lore raw

Quoted 3 lines · Benjamin Thery

Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e

How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?

thanks,

greg k-h

A message that is not in the archive (sent off-list or not yet received): [email protected]

Eric W. Biederman

2008-10-22 21:08 UTC #35 lore raw

Quoted 8 lines · Greg KH

Quoted 3 lines · Benjamin Thery
Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e
How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?

The mac address is not duplicated.

Further devices like eth0@4e are completely unusable to the udev rules in the initial network namespace because they can not talk to or affect them.

As I read it Ben's ``solution'' puts entries in sysfs that are completely unusable to udev.

Eric

Eric W. Biederman

2008-10-22 21:14 UTC #36 lore raw

In reply to Greg KH

Quoted 8 lines · Greg KH

Quoted 3 lines · Benjamin Thery
Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e
How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?

The mac address is not duplicated.

Further devices like eth0@4e are completely unusable to the udev rules in the initial network namespace because they can not talk to or affect them.

As I read it Ben's ``solution'' puts entries in sysfs that are completely unusable to udev.

Eric

A message that is not in the archive (sent off-list or not yet received): [email protected]

Greg KH

2008-10-22 21:24 UTC #38 lore raw

Quoted 7 lines · Eric W. Biederman

Quoted 5 lines · Greg KH
Quoted 3 lines · Benjamin Thery
Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e

Quoted 5 lines

Quoted 3 lines
How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?
The mac address is not duplicated.

Ah, ok, I really don't think I want to know more :)

Quoted 3 lines

Further devices like eth0@4e are completely unusable to the udev rules in the initial network namespace because they can not talk to or affect them.

Oh, good point.

Quoted 2 lines

As I read it Ben's ``solution'' puts entries in sysfs that are completely unusable to udev.

That's not a good thing to do, if udev can't see them, than HAL can't see them, then the rest of userspace usually has no idea they are present either.

thanks,

greg k-h

Greg KH

2008-10-22 21:27 UTC #39 lore raw

Quoted 7 lines · Eric W. Biederman

Quoted 5 lines · Greg KH
Quoted 3 lines · Benjamin Thery
Network devices from sub-network namespaces appear in sysfs with a name that looks like this: device_name@netns_id
eg: lo@3, eth0@4e

Quoted 5 lines

Quoted 3 lines
How does the default udev rules as shipped by most distros handle the renaming of the network device if the MAC address is duplicated like it will be for these eth devices?
The mac address is not duplicated.

Ah, ok, I really don't think I want to know more :)

Quoted 3 lines

Further devices like eth0@4e are completely unusable to the udev rules in the initial network namespace because they can not talk to or affect them.

Oh, good point.

Quoted 2 lines

As I read it Ben's ``solution'' puts entries in sysfs that are completely unusable to udev.

That's not a good thing to do, if udev can't see them, than HAL can't see them, then the rest of userspace usually has no idea they are present either.

thanks,

greg k-h

Eric W. Biederman

2008-10-22 20:34 UTC #40 lore raw

PATCH 1/1 netns: Coexist with the sysfs limitations

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.

Plus no ABIs are harmed with this patch.

Signed-off-by Eric W. Biederman <[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   12 +++++++++++-
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +11 -1

index b8a4fd0..a7f0461 100644
@@ -4449,6 +4449,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4515,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4533,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 1 line

1.5.3.rc6.17.g1911

A message that is not in the archive (sent off-list or not yet received): [email protected]

Daniel Lezcano

Acked-by

2008-10-22 20:40 UTC #42 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 13 lines · Eric W. Biederman

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.

Quoted 7 lines

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>

Acked-by Daniel Lezcano <dlezcano-NmTC/[email protected]>

Quoted 81 lines

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   12 +++++++++++-
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +11 -1

index b8a4fd0..a7f0461 100644
@@ -4449,6 +4449,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4515,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4533,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 8 lines

Sauf indication contraire ci-dessus:
Compagnie IBM France
Siège Social : Tour Descartes, 2, avenue Gambetta, La Défense 5, 92400
Courbevoie
RCS Nanterre 552 118 465
Forme Sociale : S.A.S.
Capital Social : 542.737.118 ?
SIREN/SIRET : 552 118 465 02430

Serge E. Hallyn

Tested-by Acked-by

2008-10-22 21:21 UTC #43 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 14 lines · Eric W. Biederman

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.

Quoted 7 lines

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>

Duh.

Tested-by Serge Hallyn <serue-r/[email protected]>

Thanks, Eric! Thanks, Benjamin!

-serge

Daniel Lezcano

Acked-by on v1 1/1

2008-10-22 20:40 UTC #44 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 13 lines · Eric W. Biederman

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.

Quoted 7 lines

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <[email protected]>

Acked-by Daniel Lezcano <[email protected]>

Quoted 81 lines

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   12 +++++++++++-
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +11 -1

index b8a4fd0..a7f0461 100644
@@ -4449,6 +4449,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4515,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4533,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 8 lines

Sauf indication contraire ci-dessus:
Compagnie IBM France
Siège Social : Tour Descartes, 2, avenue Gambetta, La Défense 5, 92400
Courbevoie
RCS Nanterre 552 118 465
Forme Sociale : S.A.S.
Capital Social : 542.737.118 ?
SIREN/SIRET : 552 118 465 02430

Serge E. Hallyn

Tested-by Acked-by on v1 1/1

2008-10-22 21:21 UTC #45 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 14 lines · Eric W. Biederman

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.

Quoted 7 lines

I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <[email protected]>

Duh.

Tested-by Serge Hallyn <[email protected]>

In reply to Serge E. Hallyn

Thanks, Eric! Thanks, Benjamin!

-serge

A message that is not in the archive (sent off-list or not yet received): 20081022212124.GA9910-r/[email protected]

Benjamin Thery

Acked-by

2008-10-23 08:04 UTC #47 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 18 lines · Serge E. Hallyn

Quoted 17 lines · Eric W. Biederman
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.

Quoted 8 lines

Quoted 3 lines
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>
Duh.
Tested-by Serge Hallyn <serue-r/[email protected]>
Acked-by Serge Hallyn <serue-r/[email protected]>

Oh, this patch is short, clean, and the limitation introduced isn't too annoying for testing netns right now.

At least, my proposal provoked some reactions :)

BTW, there's a second limitation with your patch:
we can't rename the net devices in the additional network namespaces.

In net/core/dev.c, dev_change_name() fails: call to device_rename() return an (expected) -EINVAL error.
Maybe we should add a test on the net to only call it in init_net?

rollback:
- err = device_rename(&dev->dev, dev->name);
- if (err) {
- memcpy(dev->name, oldname, IFNAMSIZ);
- return err;
+ if (net == &init_net) {
+ err = device_rename(&dev->dev, dev->name);
+ if (err) {
+ memcpy(dev->name, oldname, IFNAMSIZ);
+ return err;
+ }

Otherwise,

Acked-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>

Thanks,
Benjamin

Quoted 6 lines

Thanks, Eric! Thanks, Benjamin!
-serge

Signature · 3 lines

B e n j a m i n   T h e r y  - BULL/DT/Open Software R&D

    http://www.bull.com

Benjamin Thery

author Acked-by

2008-10-23 09:02 UTC #48 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 18 lines · Serge E. Hallyn

Quoted 17 lines · Eric W. Biederman
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.

Quoted 8 lines

Quoted 3 lines
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <[email protected]>
Duh.
Tested-by Serge Hallyn <[email protected]>
Acked-by Serge Hallyn <[email protected]>

Oh, this patch is short, clean, and the limitation introduced isn't too annoying for testing netns right now.

At least, my proposal provoked some reactions :)

BTW, there's a second limitation with your patch:
we can't rename the net devices in the additional network namespaces.

In net/core/dev.c, dev_change_name() fails: call to device_rename() return an (expected) -EINVAL error. Maybe we should add a test on the net to only call it in init_net?

Otherwise,

Acked-by Benjamin Thery <[email protected]>

Thanks,
Benjamin

Quoted 6 lines

Thanks, Eric! Thanks, Benjamin!
-serge

Signature · 3 lines

B e n j a m i n   T h e r y  - BULL/DT/Open Software R&D

   http://www.bull.com

A message that is not in the archive (sent off-list or not yet received): 49003019.40904-6ktuUTfB/[email protected]

Eric W. Biederman

2008-10-23 15:40 UTC #50 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 25 lines · Benjamin Thery

Quoted 24 lines · Serge E. Hallyn
Quoted 13 lines · Eric W. Biederman
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Quoted 7 lines
I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>
Duh.

Quoted 7 lines

Quoted 2 lines
Tested-by Serge Hallyn <serue-r/[email protected]>
Acked-by Serge Hallyn <serue-r/[email protected]>
Oh, this patch is short, clean, and the limitation introduced isn't too annoying for testing netns right now.
At least, my proposal provoked some reactions :)

Yes.

Quoted 6 lines

BTW, there's a second limitation with your patch:
we can't rename the net devices in the additional network namespaces.
In net/core/dev.c, dev_change_name() fails: call to device_rename() return an (expected) -EINVAL error.
Maybe we should add a test on the net to only call it in init_net?

Yes. Good catch.

Eric

Eric W. Biederman

2008-10-23 15:56 UTC #51 lore raw

PATCH 1/1 netns: Coexist with the sysfs limitations v2

Changelog:

v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.

Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>

Acked-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>

Tested-by Serge Hallyn <serue-r/[email protected]>

Acked-by Daniel Lezcano <dlezcano-NmTC/[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   25 ++++++++++++++++++++-----
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 28 insertions(+), 6 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +20 -5

index b8a4fd0..0e38594 100644
@@ -924,10 +924,15 @@ int dev_change_name(struct net_device *dev, const char *newname)
 		strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-	ret = device_rename(&dev->dev, dev->name);
-	if (ret) {
-		memcpy(dev->name, oldname, IFNAMSIZ);
-		return ret;
+	/* For now only devices in the initial network namespace
+	 * are in sysfs.
+	 */
+	if (net == &init_net) {
+		ret = device_rename(&dev->dev, dev->name);
+		if (ret) {
+			memcpy(dev->name, oldname, IFNAMSIZ);
+			return ret;
+		}
 	}
 
 	write_lock_bh(&dev_base_lock);

@@ -4449,6 +4454,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4520,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4538,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 1 line

1.5.3.rc6.17.g1911

Eric W. Biederman

2008-10-23 15:44 UTC #52 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations

Quoted 25 lines · Benjamin Thery

Quoted 24 lines · Serge E. Hallyn
Quoted 13 lines · Eric W. Biederman
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Quoted 7 lines
I.e. people running distributions that make it next to impossible to boot without sysfs should at be able to boot a test kernel now.
Plus no ABIs are harmed with this patch.
Signed-off-by Eric W. Biederman <[email protected]>
Duh.

Quoted 7 lines

Quoted 2 lines
Tested-by Serge Hallyn <[email protected]>
Acked-by Serge Hallyn <[email protected]>
Oh, this patch is short, clean, and the limitation introduced isn't too annoying for testing netns right now.
At least, my proposal provoked some reactions :)

Yes.

Quoted 6 lines

BTW, there's a second limitation with your patch:
we can't rename the net devices in the additional network namespaces.
In net/core/dev.c, dev_change_name() fails: call to device_rename() return an (expected) -EINVAL error.
Maybe we should add a test on the net to only call it in init_net?

Yes. Good catch.

Eric

Eric W. Biederman

2008-10-23 16:04 UTC #53 lore raw

PATCH 1/1 netns: Coexist with the sysfs limitations v2

Changelog:

v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.

Signed-off-by Eric W. Biederman <[email protected]>

Acked-by Benjamin Thery <[email protected]>

Tested-by Serge Hallyn <[email protected]>

Acked-by Daniel Lezcano <[email protected]>

---
 net/Kconfig          |    2 +-
 net/core/dev.c       |   25 ++++++++++++++++++++-----
 net/core/net-sysfs.c |    7 +++++++
 3 files changed, 28 insertions(+), 6 deletions(-)

net/Kconfig +1 -1

index d789d79..8c3d97c 100644
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.

net/core/dev.c +20 -5

index b8a4fd0..0e38594 100644
@@ -924,10 +924,15 @@ int dev_change_name(struct net_device *dev, const char *newname)
 		strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-	ret = device_rename(&dev->dev, dev->name);
-	if (ret) {
-		memcpy(dev->name, oldname, IFNAMSIZ);
-		return ret;
+	/* For now only devices in the initial network namespace
+	 * are in sysfs.
+	 */
+	if (net == &init_net) {
+		ret = device_rename(&dev->dev, dev->name);
+		if (ret) {
+			memcpy(dev->name, oldname, IFNAMSIZ);
+			return ret;
+		}
 	}
 
 	write_lock_bh(&dev_base_lock);

@@ -4449,6 +4454,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)

@@ -4506,6 +4520,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);

@@ -4522,7 +4538,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);

net/core/net-sysfs.c +7 -0

index 92d6b94..85cb8bd 100644
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }

@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }

Signature · 1 line

1.5.3.rc6.17.g1911

A message that is not in the archive (sent off-list or not yet received): m1fxmni9uv.fsf_-_-B27657KtZYmhTnVgQlOflh2eb7JE58TQ@public.gmane.org

David Miller

2008-10-27 19:41 UTC #55 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2

From: ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected] (Eric W. Biederman)
Date: Thu, 23 Oct 2008 08:56:08 -0700

Quoted 15 lines

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Changelog:

Quoted 8 lines

v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>
Acked-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>
Tested-by Serge Hallyn <serue-r/[email protected]>
Acked-by Serge Hallyn <serue-r/[email protected]>
Acked-by Daniel Lezcano <dlezcano-NmTC/[email protected]>

So let's figure out what happens with this patch. I'm personally ok with the change, the question is when and where.

My net-2.6 tree was closed to new features long ago, so I really don't want to try to merge this sucker into 2.6.28-rcX :-) But if you guys think that is prudent, feel free to submit it directly to Linus and add my signoff:

Signed-off-by David S. Miller <davem-fT/PcQaiUtIeIZ0/[email protected]>

otherwise if we shoot for 2.6.29 I would suggest that we wait until the merge window to see if the sysfs issues get sorted, and if not we slip this patch into to tree instead.

Let me know what you guys plan to do with this.

David Miller

maintainer

2008-10-27 19:41 UTC #56 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2

From: [email protected] (Eric W. Biederman)
Date: Thu, 23 Oct 2008 08:56:08 -0700

Quoted 15 lines

To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Changelog:

Quoted 8 lines

v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.
Signed-off-by Eric W. Biederman <[email protected]>
Acked-by Benjamin Thery <[email protected]>
Tested-by Serge Hallyn <[email protected]>
Acked-by Serge Hallyn <[email protected]>
Acked-by Daniel Lezcano <[email protected]>

So let's figure out what happens with this patch. I'm personally ok with the change, the question is when and where.

Signed-off-by David S. Miller <[email protected]>

otherwise if we shoot for 2.6.29 I would suggest that we wait until the merge window to see if the sysfs issues get sorted, and if not we slip this patch into to tree instead.

Let me know what you guys plan to do with this.

A message that is not in the archive (sent off-list or not yet received): 20081027.124126.74749150.davem-fT/PcQaiUtIeIZ0/[email protected]

Eric W. Biederman

2008-10-27 20:19 UTC #58 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2

Quoted 36 lines · David Miller

From: ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected] (Eric W. Biederman)
Date: Thu, 23 Oct 2008 08:56:08 -0700
Quoted 15 lines
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Changelog:
Quoted 8 lines
v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.
Signed-off-by Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected]>
Acked-by Benjamin Thery <benjamin.thery-6ktuUTfB/[email protected]>
Tested-by Serge Hallyn <serue-r/[email protected]>
Acked-by Serge Hallyn <serue-r/[email protected]>
Acked-by Daniel Lezcano <dlezcano-NmTC/[email protected]>
So let's figure out what happens with this patch. I'm personally ok with the change, the question is when and where.
My net-2.6 tree was closed to new features long ago, so I really don't want to try to merge this sucker into 2.6.28-rcX :-) But if you guys think that is prudent, feel free to submit it directly to Linus and add my signoff:

Quoted 7 lines

Signed-off-by David S. Miller <davem-fT/PcQaiUtIeIZ0/[email protected]>
otherwise if we shoot for 2.6.29 I would suggest that we wait until the merge window to see if the sysfs issues get sorted, and if not we slip this patch into to tree instead.
Let me know what you guys plan to do with this.

What I was thinking is that it goes into your tree for 2.6.29. Allowing for better test coverage in the short term, and removing the pressure to do a hack job on sysfs just to reduce the pain of testing.

The patch was sent during the merge window just because that is when the conversation was happening.

I guess the pain with sysfs is having multiple patches in different trees in this area causing conflicts in linux-next. Ugh. I can see why you would want to hold back. On the contrary point of view we need that patch in someones tree or else we might as well merge it now, if the plan is to merge it without it sitting in anyone's development tree.

So my plan is I'm not going to worry about that patch, and leave it to Ben and Daniel (if it needs a retransmit). If it happens to merge into net-next and that causes conflicts when we do a good job on sysfs I will handle it.

Eric

Eric W. Biederman

2008-10-27 20:25 UTC #59 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2

In reply to David Miller

Quoted 36 lines · David Miller

From: [email protected] (Eric W. Biederman)
Date: Thu, 23 Oct 2008 08:56:08 -0700
Quoted 15 lines
To make testing of the network namespace simpler allow the network namespace code and the sysfs code to be compiled and run at the same time. To do this only virtual devices are allowed in the additional network namespaces and those virtual devices are not placed in the kobject tree.
Since virtual devices don't actually do anything interesting hardware wise that needs device management there should be no loss in keeping them out of the kobject tree and by implication sysfs. The gain in ease of testing and code coverage should be significant.
Changelog:
Quoted 8 lines
v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.
Signed-off-by Eric W. Biederman <[email protected]>
Acked-by Benjamin Thery <[email protected]>
Tested-by Serge Hallyn <[email protected]>
Acked-by Serge Hallyn <[email protected]>
Acked-by Daniel Lezcano <[email protected]>
So let's figure out what happens with this patch. I'm personally ok with the change, the question is when and where.
My net-2.6 tree was closed to new features long ago, so I really don't want to try to merge this sucker into 2.6.28-rcX :-) But if you guys think that is prudent, feel free to submit it directly to Linus and add my signoff:

Quoted 7 lines

Signed-off-by David S. Miller <[email protected]>
otherwise if we shoot for 2.6.29 I would suggest that we wait until the merge window to see if the sysfs issues get sorted, and if not we slip this patch into to tree instead.
Let me know what you guys plan to do with this.

The patch was sent during the merge window just because that is when the conversation was happening.

Eric

A message that is not in the archive (sent off-list or not yet received): [email protected]

David Miller

2008-10-28 00:50 UTC #61 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2

From: ebiederm-aS9lmoZGLiVWk0Htik3J/[email protected] (Eric W. Biederman)
Date: Mon, 27 Oct 2008 13:19:27 -0700

Quoted 3 lines

What I was thinking is that it goes into your tree for 2.6.29. Allowing for better test coverage in the short term, and removing the pressure to do a hack job on sysfs just to reduce the pain of testing.

Fair enough. I'll add it to my tree.

David Miller

maintainer

2008-10-28 00:51 UTC #62 lore raw

Re: [PATCH] netns: Coexist with the sysfs limitations v2