[PATCH 0/4] generic netlink namespace awareness

[PATCH 0/4] generic netlink namespace awareness

[Johannes Berg]

This patch series makes generic netlink network namespace
aware, in some way, paving the way for making wireless
completely netns aware (which I will submit to John's tree).

The required changes are basically some preparations in
core netlink, a change to make it possible to iterate net
namespaces under just RCU (which may be useful elsewhere in
the future), the actual genetlink patch and finally also
exporting get_net_ns_by_pid() which wireless will need.

The last patch (for get_net_ns_by_pid) could go through
the wireless tree as well, but I've put it in here since
it touches core code. The others probably shouldn't go
through the wireless tree since they touch more than that.

The first patch in this series fixes the last remaining
problem I had with the generic netlink one, the patches
are actually unchanged from the previous submission other
than adding patch 1 in front.

johannes

[PATCH 0/4] generic netlink namespace awareness

[Johannes Berg]

This patch series makes generic netlink network namespace
aware, in some way, paving the way for making wireless
completely netns aware (which I will submit to John's tree).

The required changes are basically some preparations in
core netlink, a change to make it possible to iterate net
namespaces under just RCU (which may be useful elsewhere in
the future), the actual genetlink patch and finally also
exporting get_net_ns_by_pid() which wireless will need.

The last patch (for get_net_ns_by_pid) could go through
the wireless tree as well, but I've put it in here since
it touches core code. The others probably shouldn't go
through the wireless tree since they touch more than that.

The first patch in this series fixes the last remaining
problem I had with the generic netlink one, the patches
are actually unchanged from the previous submission other
than adding patch 1 in front.

johannes

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[PATCH 1/4] netlink: use call_rcu for netlink_change_ngroups

[Johannes Berg]

For the network namespace work in generic netlink I need
to be able to call this function under rcu_read_lock(),
otherwise the locking becomes a nightmare and more locks
would be needed. Instead, just embed a struct rcu_head
(actually a struct listeners_rcu_head that also carries
the pointer to the memory block) into the listeners
memory so we can use call_rcu() instead of synchronising
and then freeing. No rcu_barrier() is needed since this
code cannot be modular.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/netlink/af_netlink.c |   34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

--- wireless-testing.orig/net/netlink/af_netlink.c	2009-07-10 20:36:53.000000000 +0200
+++ wireless-testing/net/netlink/af_netlink.c	2009-07-10 20:51:40.000000000 +0200
@@ -83,6 +83,11 @@ struct netlink_sock {
 	struct module		*module;
 };
 
+struct listeners_rcu_head {
+	struct rcu_head rcu_head;
+	void *ptr;
+};
+
 #define NETLINK_KERNEL_SOCKET	0x1
 #define NETLINK_RECV_PKTINFO	0x2
 #define NETLINK_BROADCAST_SEND_ERROR	0x4
@@ -1487,7 +1492,8 @@ netlink_kernel_create(struct net *net, i
 	if (groups < 32)
 		groups = 32;
 
-	listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
+	listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head),
+			    GFP_KERNEL);
 	if (!listeners)
 		goto out_sock_release;
 
@@ -1535,6 +1541,14 @@ netlink_kernel_release(struct sock *sk)
 EXPORT_SYMBOL(netlink_kernel_release);
 
 
+static void netlink_free_old_listeners(struct rcu_head *rcu_head)
+{
+	struct listeners_rcu_head *lrh;
+
+	lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head);
+	kfree(lrh->ptr);
+}
+
 /**
  * netlink_change_ngroups - change number of multicast groups
  *
@@ -1550,6 +1564,7 @@ EXPORT_SYMBOL(netlink_kernel_release);
 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
 {
 	unsigned long *listeners, *old = NULL;
+	struct listeners_rcu_head *old_rcu_head;
 	struct netlink_table *tbl = &nl_table[sk->sk_protocol];
 	int err = 0;
 
@@ -1558,7 +1573,9 @@ int netlink_change_ngroups(struct sock *
 
 	netlink_table_grab();
 	if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
-		listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
+		listeners = kzalloc(NLGRPSZ(groups) +
+				    sizeof(struct listeners_rcu_head),
+				    GFP_ATOMIC);
 		if (!listeners) {
 			err = -ENOMEM;
 			goto out_ungrab;
@@ -1566,13 +1583,22 @@ int netlink_change_ngroups(struct sock *
 		old = tbl->listeners;
 		memcpy(listeners, old, NLGRPSZ(tbl->groups));
 		rcu_assign_pointer(tbl->listeners, listeners);
+		/*
+		 * Free the old memory after an RCU grace period so we
+		 * don't leak it. We use call_rcu() here in order to be
+		 * able to call this function from atomic contexts. The
+		 * allocation of this memory will have reserved enough
+		 * space for struct listeners_rcu_head at the end.
+		 */
+		old_rcu_head = (void *)(tbl->listeners +
+					NLGRPLONGS(tbl->groups));
+		old_rcu_head->ptr = old;
+		call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners);
 	}
 	tbl->groups = groups;
 
  out_ungrab:
 	netlink_table_ungrab();
-	synchronize_rcu();
-	kfree(old);
 	return err;
 }
 

-- 

[PATCH 1/4] netlink: use call_rcu for netlink_change_ngroups

[Johannes Berg]

[-- Attachment #1: 027-netlink-groups-realloc-rcu.patch --]
[-- Type: text/plain, Size: 3189 bytes --]

For the network namespace work in generic netlink I need
to be able to call this function under rcu_read_lock(),
otherwise the locking becomes a nightmare and more locks
would be needed. Instead, just embed a struct rcu_head
(actually a struct listeners_rcu_head that also carries
the pointer to the memory block) into the listeners
memory so we can use call_rcu() instead of synchronising
and then freeing. No rcu_barrier() is needed since this
code cannot be modular.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/netlink/af_netlink.c |   34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

--- wireless-testing.orig/net/netlink/af_netlink.c	2009-07-10 20:36:53.000000000 +0200
+++ wireless-testing/net/netlink/af_netlink.c	2009-07-10 20:51:40.000000000 +0200
@@ -83,6 +83,11 @@ struct netlink_sock {
 	struct module		*module;
 };
 
+struct listeners_rcu_head {
+	struct rcu_head rcu_head;
+	void *ptr;
+};
+
 #define NETLINK_KERNEL_SOCKET	0x1
 #define NETLINK_RECV_PKTINFO	0x2
 #define NETLINK_BROADCAST_SEND_ERROR	0x4
@@ -1487,7 +1492,8 @@ netlink_kernel_create(struct net *net, i
 	if (groups < 32)
 		groups = 32;
 
-	listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
+	listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head),
+			    GFP_KERNEL);
 	if (!listeners)
 		goto out_sock_release;
 
@@ -1535,6 +1541,14 @@ netlink_kernel_release(struct sock *sk)
 EXPORT_SYMBOL(netlink_kernel_release);
 
 
+static void netlink_free_old_listeners(struct rcu_head *rcu_head)
+{
+	struct listeners_rcu_head *lrh;
+
+	lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head);
+	kfree(lrh->ptr);
+}
+
 /**
  * netlink_change_ngroups - change number of multicast groups
  *
@@ -1550,6 +1564,7 @@ EXPORT_SYMBOL(netlink_kernel_release);
 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
 {
 	unsigned long *listeners, *old = NULL;
+	struct listeners_rcu_head *old_rcu_head;
 	struct netlink_table *tbl = &nl_table[sk->sk_protocol];
 	int err = 0;
 
@@ -1558,7 +1573,9 @@ int netlink_change_ngroups(struct sock *
 
 	netlink_table_grab();
 	if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
-		listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
+		listeners = kzalloc(NLGRPSZ(groups) +
+				    sizeof(struct listeners_rcu_head),
+				    GFP_ATOMIC);
 		if (!listeners) {
 			err = -ENOMEM;
 			goto out_ungrab;
@@ -1566,13 +1583,22 @@ int netlink_change_ngroups(struct sock *
 		old = tbl->listeners;
 		memcpy(listeners, old, NLGRPSZ(tbl->groups));
 		rcu_assign_pointer(tbl->listeners, listeners);
+		/*
+		 * Free the old memory after an RCU grace period so we
+		 * don't leak it. We use call_rcu() here in order to be
+		 * able to call this function from atomic contexts. The
+		 * allocation of this memory will have reserved enough
+		 * space for struct listeners_rcu_head at the end.
+		 */
+		old_rcu_head = (void *)(tbl->listeners +
+					NLGRPLONGS(tbl->groups));
+		old_rcu_head->ptr = old;
+		call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners);
 	}
 	tbl->groups = groups;
 
  out_ungrab:
 	netlink_table_ungrab();
-	synchronize_rcu();
-	kfree(old);
 	return err;
 }
 

-- 

[PATCH 2/4] net: make namespace iteration possible under RCU

[Johannes Berg]

All we need to take care of is using proper RCU list
add/del primitives and inserting a synchronize_rcu()
at one place to make sure the exit notifiers are run
after everybody has stopped iterating the list.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 include/net/net_namespace.h |    3 +++
 net/core/net_namespace.c    |   14 +++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

--- wireless-testing.orig/include/net/net_namespace.h	2009-07-07 04:14:39.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-07 12:17:17.000000000 +0200
@@ -211,6 +211,9 @@ static inline struct net *read_pnet(stru
 #define for_each_net(VAR)				\
 	list_for_each_entry(VAR, &net_namespace_list, list)
 
+#define for_each_net_rcu(VAR)				\
+	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
+
 #ifdef CONFIG_NET_NS
 #define __net_init
 #define __net_exit
--- wireless-testing.orig/net/core/net_namespace.c	2009-07-07 03:43:35.000000000 +0200
+++ wireless-testing/net/core/net_namespace.c	2009-07-07 12:18:19.000000000 +0200
@@ -6,6 +6,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/idr.h>
+#include <linux/rculist.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -127,7 +128,7 @@ static struct net *net_create(void)
 	rv = setup_net(net);
 	if (rv == 0) {
 		rtnl_lock();
-		list_add_tail(&net->list, &net_namespace_list);
+		list_add_tail_rcu(&net->list, &net_namespace_list);
 		rtnl_unlock();
 	}
 	mutex_unlock(&net_mutex);
@@ -156,9 +157,16 @@ static void cleanup_net(struct work_stru
 
 	/* Don't let anyone else find us. */
 	rtnl_lock();
-	list_del(&net->list);
+	list_del_rcu(&net->list);
 	rtnl_unlock();
 
+	/*
+	 * Another CPU might be rcu-iterating the list, wait for it.
+	 * This needs to be before calling the exit() notifiers, so
+	 * the rcu_barrier() below isn't sufficient alone.
+	 */
+	synchronize_rcu();
+
 	/* Run all of the network namespace exit methods */
 	list_for_each_entry_reverse(ops, &pernet_list, list) {
 		if (ops->exit)
@@ -219,7 +227,7 @@ static int __init net_ns_init(void)
 		panic("Could not setup the initial network namespace");
 
 	rtnl_lock();
-	list_add_tail(&init_net.list, &net_namespace_list);
+	list_add_tail_rcu(&init_net.list, &net_namespace_list);
 	rtnl_unlock();
 
 	mutex_unlock(&net_mutex);

-- 

[PATCH 2/4] net: make namespace iteration possible under RCU

[Johannes Berg]

[-- Attachment #1: 028-netns-rcu.patch --]
[-- Type: text/plain, Size: 2589 bytes --]

All we need to take care of is using proper RCU list
add/del primitives and inserting a synchronize_rcu()
at one place to make sure the exit notifiers are run
after everybody has stopped iterating the list.

Signed-off-by: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
---
 include/net/net_namespace.h |    3 +++
 net/core/net_namespace.c    |   14 +++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

--- wireless-testing.orig/include/net/net_namespace.h	2009-07-07 04:14:39.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-07 12:17:17.000000000 +0200
@@ -211,6 +211,9 @@ static inline struct net *read_pnet(stru
 #define for_each_net(VAR)				\
 	list_for_each_entry(VAR, &net_namespace_list, list)
 
+#define for_each_net_rcu(VAR)				\
+	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
+
 #ifdef CONFIG_NET_NS
 #define __net_init
 #define __net_exit
--- wireless-testing.orig/net/core/net_namespace.c	2009-07-07 03:43:35.000000000 +0200
+++ wireless-testing/net/core/net_namespace.c	2009-07-07 12:18:19.000000000 +0200
@@ -6,6 +6,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/idr.h>
+#include <linux/rculist.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -127,7 +128,7 @@ static struct net *net_create(void)
 	rv = setup_net(net);
 	if (rv == 0) {
 		rtnl_lock();
-		list_add_tail(&net->list, &net_namespace_list);
+		list_add_tail_rcu(&net->list, &net_namespace_list);
 		rtnl_unlock();
 	}
 	mutex_unlock(&net_mutex);
@@ -156,9 +157,16 @@ static void cleanup_net(struct work_stru
 
 	/* Don't let anyone else find us. */
 	rtnl_lock();
-	list_del(&net->list);
+	list_del_rcu(&net->list);
 	rtnl_unlock();
 
+	/*
+	 * Another CPU might be rcu-iterating the list, wait for it.
+	 * This needs to be before calling the exit() notifiers, so
+	 * the rcu_barrier() below isn't sufficient alone.
+	 */
+	synchronize_rcu();
+
 	/* Run all of the network namespace exit methods */
 	list_for_each_entry_reverse(ops, &pernet_list, list) {
 		if (ops->exit)
@@ -219,7 +227,7 @@ static int __init net_ns_init(void)
 		panic("Could not setup the initial network namespace");
 
 	rtnl_lock();
-	list_add_tail(&init_net.list, &net_namespace_list);
+	list_add_tail_rcu(&init_net.list, &net_namespace_list);
 	rtnl_unlock();
 
 	mutex_unlock(&net_mutex);

-- 

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[PATCH 3/4] genetlink: make netns aware

[Johannes Berg]

This makes generic netlink network namespace aware. No
generic netlink families except for the controller family
are made namespace aware, they need to be checked one by
one and then set the family->netnsok member to true.

A new function genlmsg_multicast_netns() is introduced to
allow sending a multicast message in a given namespace,
for example when it applies to an object that lives in
that namespace, a new function genlmsg_multicast_allns()
to send a message to all network namespaces (for objects
that do not have an associated netns).

The function genlmsg_multicast() is changed to multicast
the message in just init_net, which is currently correct
for all generic netlink families since they only work in
init_net right now. Some will later want to work in all
net namespaces because they do not care about the netns
at all -- those will have to be converted to use one of
the new functions genlmsg_multicast_allns() or
genlmsg_multicast_netns() whenever they are made netns
aware in some way.

After this patch families can easily decide whether or
not they should be available in all net namespaces. Many
genl families us it for objects not related to networking
and should therefore be available in all namespaces, but
that will have to be done on a per family basis.

Note that this doesn't touch on the checkpoint/restart
problem where network namespaces could be used, genl
families and multicast groups are numbered globally and
I see no easy way of changing that, especially since it
must be possible to multicast to all network namespaces
for those families that do not care about netns.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 fs/dlm/netlink.c               |    2 
 include/net/genetlink.h        |   66 +++++++++++++-
 include/net/net_namespace.h    |    2 
 kernel/taskstats.c             |   10 +-
 net/irda/irnetlink.c           |    2 
 net/netfilter/ipvs/ip_vs_ctl.c |    2 
 net/netlink/genetlink.c        |  186 ++++++++++++++++++++++++++++++++---------
 net/tipc/netlink.c             |    2 
 net/wireless/nl80211.c         |   14 +--
 9 files changed, 223 insertions(+), 63 deletions(-)

--- wireless-testing.orig/include/net/genetlink.h	2009-07-08 14:11:56.000000000 +0200
+++ wireless-testing/include/net/genetlink.h	2009-07-08 15:01:54.000000000 +0200
@@ -3,6 +3,7 @@
 
 #include <linux/genetlink.h>
 #include <net/netlink.h>
+#include <net/net_namespace.h>
 
 /**
  * struct genl_multicast_group - generic netlink multicast group
@@ -27,6 +28,8 @@ struct genl_multicast_group
  * @name: name of family
  * @version: protocol version
  * @maxattr: maximum number of attributes supported
+ * @netnsok: set to true if the family can handle network
+ *	namespaces and should be presented in all of them
  * @attrbuf: buffer to store parsed attributes
  * @ops_list: list of all assigned operations
  * @family_list: family list
@@ -39,6 +42,7 @@ struct genl_family
 	char			name[GENL_NAMSIZ];
 	unsigned int		version;
 	unsigned int		maxattr;
+	bool			netnsok;
 	struct nlattr **	attrbuf;	/* private */
 	struct list_head	ops_list;	/* private */
 	struct list_head	family_list;	/* private */
@@ -62,8 +66,32 @@ struct genl_info
 	struct genlmsghdr *	genlhdr;
 	void *			userhdr;
 	struct nlattr **	attrs;
+#ifdef CONFIG_NET_NS
+	struct net *		_net;
+#endif
 };
 
+#ifdef CONFIG_NET_NS
+static inline struct net *genl_info_net(struct genl_info *info)
+{
+	return info->_net;
+}
+
+static inline void genl_info_net_set(struct genl_info *info, struct net *net)
+{
+	info->_net = net;
+}
+#else
+static inline struct net *genl_info_net(struct genl_info *info)
+{
+	return &init_net;
+}
+
+static inline void genl_info_net_set(struct genl_info *info, struct net *net)
+{
+}
+#endif
+
 /**
  * struct genl_ops - generic netlink operations
  * @cmd: command identifier
@@ -98,8 +126,6 @@ extern int genl_register_mc_group(struct
 extern void genl_unregister_mc_group(struct genl_family *family,
 				     struct genl_multicast_group *grp);
 
-extern struct sock *genl_sock;
-
 /**
  * genlmsg_put - Add generic netlink header to netlink message
  * @skb: socket buffer holding the message
@@ -170,7 +196,21 @@ static inline void genlmsg_cancel(struct
 }
 
 /**
- * genlmsg_multicast - multicast a netlink message
+ * genlmsg_multicast_netns - multicast a netlink message to a specific netns
+ * @net: the net namespace
+ * @skb: netlink message as socket buffer
+ * @pid: own netlink pid to avoid sending to yourself
+ * @group: multicast group id
+ * @flags: allocation flags
+ */
+static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
+					  u32 pid, unsigned int group, gfp_t flags)
+{
+	return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
+}
+
+/**
+ * genlmsg_multicast - multicast a netlink message to the default netns
  * @skb: netlink message as socket buffer
  * @pid: own netlink pid to avoid sending to yourself
  * @group: multicast group id
@@ -179,17 +219,29 @@ static inline void genlmsg_cancel(struct
 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 				    unsigned int group, gfp_t flags)
 {
-	return nlmsg_multicast(genl_sock, skb, pid, group, flags);
+	return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
 }
 
 /**
+ * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
+ * @skb: netlink message as socket buffer
+ * @pid: own netlink pid to avoid sending to yourself
+ * @group: multicast group id
+ * @flags: allocation flags
+ *
+ * This function must hold the RTNL or rcu_read_lock().
+ */
+int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
+			    unsigned int group, gfp_t flags);
+
+/**
  * genlmsg_unicast - unicast a netlink message
  * @skb: netlink message as socket buffer
  * @pid: netlink pid of the destination socket
  */
-static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
+static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
 {
-	return nlmsg_unicast(genl_sock, skb, pid);
+	return nlmsg_unicast(net->genl_sock, skb, pid);
 }
 
 /**
@@ -199,7 +251,7 @@ static inline int genlmsg_unicast(struct
  */
 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
 {
-	return genlmsg_unicast(skb, info->snd_pid);
+	return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
 }
 
 /**
--- wireless-testing.orig/net/netlink/genetlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/netlink/genetlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -18,8 +18,6 @@
 #include <net/sock.h>
 #include <net/genetlink.h>
 
-struct sock *genl_sock = NULL;
-
 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
 
 static inline void genl_lock(void)
@@ -175,10 +173,31 @@ int genl_register_mc_group(struct genl_f
 		mc_groups_longs++;
 	}
 
-	err = netlink_change_ngroups(genl_sock,
-				     mc_groups_longs * BITS_PER_LONG);
-	if (err)
-		goto out;
+	if (family->netnsok) {
+		struct net *net;
+
+		rcu_read_lock();
+		for_each_net_rcu(net) {
+			err = netlink_change_ngroups(net->genl_sock,
+					mc_groups_longs * BITS_PER_LONG);
+			if (err) {
+				/*
+				 * No need to roll back, can only fail if
+				 * memory allocation fails and then the
+				 * number of _possible_ groups has been
+				 * increased on some sockets which is ok.
+				 */
+				rcu_read_unlock();
+				goto out;
+			}
+		}
+		rcu_read_unlock();
+	} else {
+		err = netlink_change_ngroups(init_net.genl_sock,
+					     mc_groups_longs * BITS_PER_LONG);
+		if (err)
+			goto out;
+	}
 
 	grp->id = id;
 	set_bit(id, mc_groups);
@@ -195,8 +214,14 @@ EXPORT_SYMBOL(genl_register_mc_group);
 static void __genl_unregister_mc_group(struct genl_family *family,
 				       struct genl_multicast_group *grp)
 {
+	struct net *net;
 	BUG_ON(grp->family != family);
-	netlink_clear_multicast_users(genl_sock, grp->id);
+
+	rcu_read_lock();
+	for_each_net_rcu(net)
+		netlink_clear_multicast_users(net->genl_sock, grp->id);
+	rcu_read_unlock();
+
 	clear_bit(grp->id, mc_groups);
 	list_del(&grp->list);
 	genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
@@ -467,6 +492,7 @@ static int genl_rcv_msg(struct sk_buff *
 {
 	struct genl_ops *ops;
 	struct genl_family *family;
+	struct net *net = sock_net(skb->sk);
 	struct genl_info info;
 	struct genlmsghdr *hdr = nlmsg_data(nlh);
 	int hdrlen, err;
@@ -475,6 +501,10 @@ static int genl_rcv_msg(struct sk_buff *
 	if (family == NULL)
 		return -ENOENT;
 
+	/* this family doesn't exist in this netns */
+	if (!family->netnsok && !net_eq(net, &init_net))
+		return -ENOENT;
+
 	hdrlen = GENL_HDRLEN + family->hdrsize;
 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 		return -EINVAL;
@@ -492,7 +522,7 @@ static int genl_rcv_msg(struct sk_buff *
 			return -EOPNOTSUPP;
 
 		genl_unlock();
-		err = netlink_dump_start(genl_sock, skb, nlh,
+		err = netlink_dump_start(net->genl_sock, skb, nlh,
 					 ops->dumpit, ops->done);
 		genl_lock();
 		return err;
@@ -514,6 +544,7 @@ static int genl_rcv_msg(struct sk_buff *
 	info.genlhdr = nlmsg_data(nlh);
 	info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
 	info.attrs = family->attrbuf;
+	genl_info_net_set(&info, net);
 
 	return ops->doit(skb, &info);
 }
@@ -534,6 +565,7 @@ static struct genl_family genl_ctrl = {
 	.name = "nlctrl",
 	.version = 0x2,
 	.maxattr = CTRL_ATTR_MAX,
+	.netnsok = true,
 };
 
 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
@@ -650,6 +682,7 @@ static int ctrl_dumpfamily(struct sk_buf
 
 	int i, n = 0;
 	struct genl_family *rt;
+	struct net *net = sock_net(skb->sk);
 	int chains_to_skip = cb->args[0];
 	int fams_to_skip = cb->args[1];
 
@@ -658,6 +691,8 @@ static int ctrl_dumpfamily(struct sk_buf
 			continue;
 		n = 0;
 		list_for_each_entry(rt, genl_family_chain(i), family_list) {
+			if (!rt->netnsok && !net_eq(net, &init_net))
+				continue;
 			if (++n < fams_to_skip)
 				continue;
 			if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
@@ -729,6 +764,7 @@ static int ctrl_getfamily(struct sk_buff
 	if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
 		u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
 		res = genl_family_find_byid(id);
+		err = -ENOENT;
 	}
 
 	if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
@@ -736,49 +772,61 @@ static int ctrl_getfamily(struct sk_buff
 
 		name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
 		res = genl_family_find_byname(name);
+		err = -ENOENT;
 	}
 
-	if (res == NULL) {
-		err = -ENOENT;
-		goto errout;
+	if (res == NULL)
+		return err;
+
+	if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
+		/* family doesn't exist here */
+		return -ENOENT;
 	}
 
 	msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
 				    CTRL_CMD_NEWFAMILY);
-	if (IS_ERR(msg)) {
-		err = PTR_ERR(msg);
-		goto errout;
-	}
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
 
-	err = genlmsg_reply(msg, info);
-errout:
-	return err;
+	return genlmsg_reply(msg, info);
 }
 
 static int genl_ctrl_event(int event, void *data)
 {
 	struct sk_buff *msg;
+	struct genl_family *family;
+	struct genl_multicast_group *grp;
 
-	if (genl_sock == NULL)
+	/* genl is still initialising */
+	if (!init_net.genl_sock)
 		return 0;
 
 	switch (event) {
 	case CTRL_CMD_NEWFAMILY:
 	case CTRL_CMD_DELFAMILY:
-		msg = ctrl_build_family_msg(data, 0, 0, event);
-		if (IS_ERR(msg))
-			return PTR_ERR(msg);
-
-		genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+		family = data;
+		msg = ctrl_build_family_msg(family, 0, 0, event);
 		break;
 	case CTRL_CMD_NEWMCAST_GRP:
 	case CTRL_CMD_DELMCAST_GRP:
+		grp = data;
+		family = grp->family;
 		msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
-		if (IS_ERR(msg))
-			return PTR_ERR(msg);
-
-		genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
 		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
+
+	if (!family->netnsok) {
+		genlmsg_multicast_netns(&init_net, msg, 0,
+					GENL_ID_CTRL, GFP_KERNEL);
+	} else {
+		rcu_read_lock();
+		genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
+		rcu_read_unlock();
 	}
 
 	return 0;
@@ -795,6 +843,33 @@ static struct genl_multicast_group notif
 	.name		= "notify",
 };
 
+static int __net_init genl_pernet_init(struct net *net)
+{
+	/* we'll bump the group number right afterwards */
+	net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
+					       genl_rcv, &genl_mutex,
+					       THIS_MODULE);
+
+	if (!net->genl_sock && net_eq(net, &init_net))
+		panic("GENL: Cannot initialize generic netlink\n");
+
+	if (!net->genl_sock)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void __net_exit genl_pernet_exit(struct net *net)
+{
+	netlink_kernel_release(net->genl_sock);
+	net->genl_sock = NULL;
+}
+
+static struct pernet_operations genl_pernet_ops = {
+	.init = genl_pernet_init,
+	.exit = genl_pernet_exit,
+};
+
 static int __init genl_init(void)
 {
 	int i, err;
@@ -804,36 +879,67 @@ static int __init genl_init(void)
 
 	err = genl_register_family(&genl_ctrl);
 	if (err < 0)
-		goto errout;
+		goto problem;
 
 	err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
 	if (err < 0)
-		goto errout_register;
+		goto problem;
 
 	netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
 
-	/* we'll bump the group number right afterwards */
-	genl_sock = netlink_kernel_create(&init_net, NETLINK_GENERIC, 0,
-					  genl_rcv, &genl_mutex, THIS_MODULE);
-	if (genl_sock == NULL)
-		panic("GENL: Cannot initialize generic netlink\n");
+	err = register_pernet_subsys(&genl_pernet_ops);
+	if (err)
+		goto problem;
 
 	err = genl_register_mc_group(&genl_ctrl, &notify_grp);
 	if (err < 0)
-		goto errout_register;
+		goto problem;
 
 	return 0;
 
-errout_register:
-	genl_unregister_family(&genl_ctrl);
-errout:
+problem:
 	panic("GENL: Cannot register controller: %d\n", err);
 }
 
 subsys_initcall(genl_init);
 
-EXPORT_SYMBOL(genl_sock);
 EXPORT_SYMBOL(genl_register_ops);
 EXPORT_SYMBOL(genl_unregister_ops);
 EXPORT_SYMBOL(genl_register_family);
 EXPORT_SYMBOL(genl_unregister_family);
+
+static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
+			 gfp_t flags)
+{
+	struct sk_buff *tmp;
+	struct net *net, *prev = NULL;
+	int err;
+
+	for_each_net_rcu(net) {
+		if (prev) {
+			tmp = skb_clone(skb, flags);
+			if (!tmp) {
+				err = -ENOMEM;
+				goto error;
+			}
+			err = nlmsg_multicast(prev->genl_sock, tmp,
+					      pid, group, flags);
+			if (err)
+				goto error;
+		}
+
+		prev = net;
+	}
+
+	return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
+ error:
+	kfree_skb(skb);
+	return err;
+}
+
+int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
+			    gfp_t flags)
+{
+	return genlmsg_mcast(skb, pid, group, flags);
+}
+EXPORT_SYMBOL(genlmsg_multicast_allns);
--- wireless-testing.orig/fs/dlm/netlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/fs/dlm/netlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -63,7 +63,7 @@ static int send_data(struct sk_buff *skb
 		return rv;
 	}
 
-	return genlmsg_unicast(skb, listener_nlpid);
+	return genlmsg_unicast(&init_net, skb, listener_nlpid);
 }
 
 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
--- wireless-testing.orig/kernel/taskstats.c	2009-07-08 14:11:56.000000000 +0200
+++ wireless-testing/kernel/taskstats.c	2009-07-08 15:01:54.000000000 +0200
@@ -108,7 +108,7 @@ static int prepare_reply(struct genl_inf
 /*
  * Send taskstats data in @skb to listener with nl_pid @pid
  */
-static int send_reply(struct sk_buff *skb, pid_t pid)
+static int send_reply(struct sk_buff *skb, struct genl_info *info)
 {
 	struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
 	void *reply = genlmsg_data(genlhdr);
@@ -120,7 +120,7 @@ static int send_reply(struct sk_buff *sk
 		return rc;
 	}
 
-	return genlmsg_unicast(skb, pid);
+	return genlmsg_reply(skb, info);
 }
 
 /*
@@ -150,7 +150,7 @@ static void send_cpu_listeners(struct sk
 			if (!skb_next)
 				break;
 		}
-		rc = genlmsg_unicast(skb_cur, s->pid);
+		rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
 		if (rc == -ECONNREFUSED) {
 			s->valid = 0;
 			delcount++;
@@ -418,7 +418,7 @@ static int cgroupstats_user_cmd(struct s
 		goto err;
 	}
 
-	rc = send_reply(rep_skb, info->snd_pid);
+	rc = send_reply(rep_skb, info);
 
 err:
 	fput_light(file, fput_needed);
@@ -487,7 +487,7 @@ free_return_rc:
 	} else
 		goto err;
 
-	return send_reply(rep_skb, info->snd_pid);
+	return send_reply(rep_skb, info);
 err:
 	nlmsg_free(rep_skb);
 	return rc;
--- wireless-testing.orig/net/irda/irnetlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/irda/irnetlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -115,7 +115,7 @@ static int irda_nl_get_mode(struct sk_bu
 
 	genlmsg_end(msg, hdr);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  err_out:
 	nlmsg_free(msg);
--- wireless-testing.orig/net/netfilter/ipvs/ip_vs_ctl.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/netfilter/ipvs/ip_vs_ctl.c	2009-07-08 15:01:55.000000000 +0200
@@ -3231,7 +3231,7 @@ static int ip_vs_genl_get_cmd(struct sk_
 	}
 
 	genlmsg_end(msg, reply);
-	ret = genlmsg_unicast(msg, info->snd_pid);
+	ret = genlmsg_reply(msg, info);
 	goto out;
 
 nla_put_failure:
--- wireless-testing.orig/net/tipc/netlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/tipc/netlink.c	2009-07-08 15:01:55.000000000 +0200
@@ -62,7 +62,7 @@ static int handle_cmd(struct sk_buff *sk
 		rep_nlh = nlmsg_hdr(rep_buf);
 		memcpy(rep_nlh, req_nlh, hdr_space);
 		rep_nlh->nlmsg_len = rep_buf->len;
-		genlmsg_unicast(rep_buf, NETLINK_CB(skb).pid);
+		genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).pid);
 	}
 
 	return 0;
--- wireless-testing.orig/net/wireless/nl80211.c	2009-07-08 14:12:35.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c	2009-07-08 15:01:55.000000000 +0200
@@ -596,7 +596,7 @@ static int nl80211_get_wiphy(struct sk_b
 
 	cfg80211_unlock_rdev(dev);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  out_free:
 	nlmsg_free(msg);
@@ -922,7 +922,7 @@ static int nl80211_get_interface(struct 
 	dev_put(netdev);
 	cfg80211_unlock_rdev(dev);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  out_free:
 	nlmsg_free(msg);
@@ -1236,7 +1236,7 @@ static int nl80211_get_key(struct sk_buf
 		goto nla_put_failure;
 
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  nla_put_failure:
@@ -1811,7 +1811,7 @@ static int nl80211_get_station(struct sk
 				 dev, mac_addr, &sinfo) < 0)
 		goto out_free;
 
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  out_free:
@@ -2280,7 +2280,7 @@ static int nl80211_get_mpath(struct sk_b
 				 dev, dst, next_hop, &pinfo) < 0)
 		goto out_free;
 
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  out_free:
@@ -2629,7 +2629,7 @@ static int nl80211_get_mesh_params(struc
 			cur_params.dot11MeshHWMPnetDiameterTraversalTime);
 	nla_nest_end(msg, pinfoattr);
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  nla_put_failure:
@@ -2817,7 +2817,7 @@ static int nl80211_get_reg(struct sk_buf
 	nla_nest_end(msg, nl_reg_rules);
 
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
 nla_put_failure:
--- wireless-testing.orig/include/net/net_namespace.h	2009-07-08 15:01:53.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-08 15:01:55.000000000 +0200
@@ -26,6 +26,7 @@ struct net_device;
 struct sock;
 struct ctl_table_header;
 struct net_generic;
+struct sock;
 
 struct net {
 	atomic_t		count;		/* To decided when the network
@@ -57,6 +58,7 @@ struct net {
 	spinlock_t		rules_mod_lock;
 
 	struct sock 		*rtnl;			/* rtnetlink socket */
+	struct sock		*genl_sock;
 
 	struct netns_core	core;
 	struct netns_mib	mib;

-- 

[PATCH 3/4] genetlink: make netns aware

[Johannes Berg]

[-- Attachment #1: 029-genl-netns.patch --]
[-- Type: text/plain, Size: 20230 bytes --]

This makes generic netlink network namespace aware. No
generic netlink families except for the controller family
are made namespace aware, they need to be checked one by
one and then set the family->netnsok member to true.

A new function genlmsg_multicast_netns() is introduced to
allow sending a multicast message in a given namespace,
for example when it applies to an object that lives in
that namespace, a new function genlmsg_multicast_allns()
to send a message to all network namespaces (for objects
that do not have an associated netns).

The function genlmsg_multicast() is changed to multicast
the message in just init_net, which is currently correct
for all generic netlink families since they only work in
init_net right now. Some will later want to work in all
net namespaces because they do not care about the netns
at all -- those will have to be converted to use one of
the new functions genlmsg_multicast_allns() or
genlmsg_multicast_netns() whenever they are made netns
aware in some way.

After this patch families can easily decide whether or
not they should be available in all net namespaces. Many
genl families us it for objects not related to networking
and should therefore be available in all namespaces, but
that will have to be done on a per family basis.

Note that this doesn't touch on the checkpoint/restart
problem where network namespaces could be used, genl
families and multicast groups are numbered globally and
I see no easy way of changing that, especially since it
must be possible to multicast to all network namespaces
for those families that do not care about netns.

Signed-off-by: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
---
 fs/dlm/netlink.c               |    2 
 include/net/genetlink.h        |   66 +++++++++++++-
 include/net/net_namespace.h    |    2 
 kernel/taskstats.c             |   10 +-
 net/irda/irnetlink.c           |    2 
 net/netfilter/ipvs/ip_vs_ctl.c |    2 
 net/netlink/genetlink.c        |  186 ++++++++++++++++++++++++++++++++---------
 net/tipc/netlink.c             |    2 
 net/wireless/nl80211.c         |   14 +--
 9 files changed, 223 insertions(+), 63 deletions(-)

--- wireless-testing.orig/include/net/genetlink.h	2009-07-08 14:11:56.000000000 +0200
+++ wireless-testing/include/net/genetlink.h	2009-07-08 15:01:54.000000000 +0200
@@ -3,6 +3,7 @@
 
 #include <linux/genetlink.h>
 #include <net/netlink.h>
+#include <net/net_namespace.h>
 
 /**
  * struct genl_multicast_group - generic netlink multicast group
@@ -27,6 +28,8 @@ struct genl_multicast_group
  * @name: name of family
  * @version: protocol version
  * @maxattr: maximum number of attributes supported
+ * @netnsok: set to true if the family can handle network
+ *	namespaces and should be presented in all of them
  * @attrbuf: buffer to store parsed attributes
  * @ops_list: list of all assigned operations
  * @family_list: family list
@@ -39,6 +42,7 @@ struct genl_family
 	char			name[GENL_NAMSIZ];
 	unsigned int		version;
 	unsigned int		maxattr;
+	bool			netnsok;
 	struct nlattr **	attrbuf;	/* private */
 	struct list_head	ops_list;	/* private */
 	struct list_head	family_list;	/* private */
@@ -62,8 +66,32 @@ struct genl_info
 	struct genlmsghdr *	genlhdr;
 	void *			userhdr;
 	struct nlattr **	attrs;
+#ifdef CONFIG_NET_NS
+	struct net *		_net;
+#endif
 };
 
+#ifdef CONFIG_NET_NS
+static inline struct net *genl_info_net(struct genl_info *info)
+{
+	return info->_net;
+}
+
+static inline void genl_info_net_set(struct genl_info *info, struct net *net)
+{
+	info->_net = net;
+}
+#else
+static inline struct net *genl_info_net(struct genl_info *info)
+{
+	return &init_net;
+}
+
+static inline void genl_info_net_set(struct genl_info *info, struct net *net)
+{
+}
+#endif
+
 /**
  * struct genl_ops - generic netlink operations
  * @cmd: command identifier
@@ -98,8 +126,6 @@ extern int genl_register_mc_group(struct
 extern void genl_unregister_mc_group(struct genl_family *family,
 				     struct genl_multicast_group *grp);
 
-extern struct sock *genl_sock;
-
 /**
  * genlmsg_put - Add generic netlink header to netlink message
  * @skb: socket buffer holding the message
@@ -170,7 +196,21 @@ static inline void genlmsg_cancel(struct
 }
 
 /**
- * genlmsg_multicast - multicast a netlink message
+ * genlmsg_multicast_netns - multicast a netlink message to a specific netns
+ * @net: the net namespace
+ * @skb: netlink message as socket buffer
+ * @pid: own netlink pid to avoid sending to yourself
+ * @group: multicast group id
+ * @flags: allocation flags
+ */
+static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
+					  u32 pid, unsigned int group, gfp_t flags)
+{
+	return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
+}
+
+/**
+ * genlmsg_multicast - multicast a netlink message to the default netns
  * @skb: netlink message as socket buffer
  * @pid: own netlink pid to avoid sending to yourself
  * @group: multicast group id
@@ -179,17 +219,29 @@ static inline void genlmsg_cancel(struct
 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 				    unsigned int group, gfp_t flags)
 {
-	return nlmsg_multicast(genl_sock, skb, pid, group, flags);
+	return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
 }
 
 /**
+ * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
+ * @skb: netlink message as socket buffer
+ * @pid: own netlink pid to avoid sending to yourself
+ * @group: multicast group id
+ * @flags: allocation flags
+ *
+ * This function must hold the RTNL or rcu_read_lock().
+ */
+int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
+			    unsigned int group, gfp_t flags);
+
+/**
  * genlmsg_unicast - unicast a netlink message
  * @skb: netlink message as socket buffer
  * @pid: netlink pid of the destination socket
  */
-static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
+static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
 {
-	return nlmsg_unicast(genl_sock, skb, pid);
+	return nlmsg_unicast(net->genl_sock, skb, pid);
 }
 
 /**
@@ -199,7 +251,7 @@ static inline int genlmsg_unicast(struct
  */
 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
 {
-	return genlmsg_unicast(skb, info->snd_pid);
+	return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
 }
 
 /**
--- wireless-testing.orig/net/netlink/genetlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/netlink/genetlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -18,8 +18,6 @@
 #include <net/sock.h>
 #include <net/genetlink.h>
 
-struct sock *genl_sock = NULL;
-
 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
 
 static inline void genl_lock(void)
@@ -175,10 +173,31 @@ int genl_register_mc_group(struct genl_f
 		mc_groups_longs++;
 	}
 
-	err = netlink_change_ngroups(genl_sock,
-				     mc_groups_longs * BITS_PER_LONG);
-	if (err)
-		goto out;
+	if (family->netnsok) {
+		struct net *net;
+
+		rcu_read_lock();
+		for_each_net_rcu(net) {
+			err = netlink_change_ngroups(net->genl_sock,
+					mc_groups_longs * BITS_PER_LONG);
+			if (err) {
+				/*
+				 * No need to roll back, can only fail if
+				 * memory allocation fails and then the
+				 * number of _possible_ groups has been
+				 * increased on some sockets which is ok.
+				 */
+				rcu_read_unlock();
+				goto out;
+			}
+		}
+		rcu_read_unlock();
+	} else {
+		err = netlink_change_ngroups(init_net.genl_sock,
+					     mc_groups_longs * BITS_PER_LONG);
+		if (err)
+			goto out;
+	}
 
 	grp->id = id;
 	set_bit(id, mc_groups);
@@ -195,8 +214,14 @@ EXPORT_SYMBOL(genl_register_mc_group);
 static void __genl_unregister_mc_group(struct genl_family *family,
 				       struct genl_multicast_group *grp)
 {
+	struct net *net;
 	BUG_ON(grp->family != family);
-	netlink_clear_multicast_users(genl_sock, grp->id);
+
+	rcu_read_lock();
+	for_each_net_rcu(net)
+		netlink_clear_multicast_users(net->genl_sock, grp->id);
+	rcu_read_unlock();
+
 	clear_bit(grp->id, mc_groups);
 	list_del(&grp->list);
 	genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
@@ -467,6 +492,7 @@ static int genl_rcv_msg(struct sk_buff *
 {
 	struct genl_ops *ops;
 	struct genl_family *family;
+	struct net *net = sock_net(skb->sk);
 	struct genl_info info;
 	struct genlmsghdr *hdr = nlmsg_data(nlh);
 	int hdrlen, err;
@@ -475,6 +501,10 @@ static int genl_rcv_msg(struct sk_buff *
 	if (family == NULL)
 		return -ENOENT;
 
+	/* this family doesn't exist in this netns */
+	if (!family->netnsok && !net_eq(net, &init_net))
+		return -ENOENT;
+
 	hdrlen = GENL_HDRLEN + family->hdrsize;
 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 		return -EINVAL;
@@ -492,7 +522,7 @@ static int genl_rcv_msg(struct sk_buff *
 			return -EOPNOTSUPP;
 
 		genl_unlock();
-		err = netlink_dump_start(genl_sock, skb, nlh,
+		err = netlink_dump_start(net->genl_sock, skb, nlh,
 					 ops->dumpit, ops->done);
 		genl_lock();
 		return err;
@@ -514,6 +544,7 @@ static int genl_rcv_msg(struct sk_buff *
 	info.genlhdr = nlmsg_data(nlh);
 	info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
 	info.attrs = family->attrbuf;
+	genl_info_net_set(&info, net);
 
 	return ops->doit(skb, &info);
 }
@@ -534,6 +565,7 @@ static struct genl_family genl_ctrl = {
 	.name = "nlctrl",
 	.version = 0x2,
 	.maxattr = CTRL_ATTR_MAX,
+	.netnsok = true,
 };
 
 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
@@ -650,6 +682,7 @@ static int ctrl_dumpfamily(struct sk_buf
 
 	int i, n = 0;
 	struct genl_family *rt;
+	struct net *net = sock_net(skb->sk);
 	int chains_to_skip = cb->args[0];
 	int fams_to_skip = cb->args[1];
 
@@ -658,6 +691,8 @@ static int ctrl_dumpfamily(struct sk_buf
 			continue;
 		n = 0;
 		list_for_each_entry(rt, genl_family_chain(i), family_list) {
+			if (!rt->netnsok && !net_eq(net, &init_net))
+				continue;
 			if (++n < fams_to_skip)
 				continue;
 			if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
@@ -729,6 +764,7 @@ static int ctrl_getfamily(struct sk_buff
 	if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
 		u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
 		res = genl_family_find_byid(id);
+		err = -ENOENT;
 	}
 
 	if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
@@ -736,49 +772,61 @@ static int ctrl_getfamily(struct sk_buff
 
 		name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
 		res = genl_family_find_byname(name);
+		err = -ENOENT;
 	}
 
-	if (res == NULL) {
-		err = -ENOENT;
-		goto errout;
+	if (res == NULL)
+		return err;
+
+	if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
+		/* family doesn't exist here */
+		return -ENOENT;
 	}
 
 	msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
 				    CTRL_CMD_NEWFAMILY);
-	if (IS_ERR(msg)) {
-		err = PTR_ERR(msg);
-		goto errout;
-	}
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
 
-	err = genlmsg_reply(msg, info);
-errout:
-	return err;
+	return genlmsg_reply(msg, info);
 }
 
 static int genl_ctrl_event(int event, void *data)
 {
 	struct sk_buff *msg;
+	struct genl_family *family;
+	struct genl_multicast_group *grp;
 
-	if (genl_sock == NULL)
+	/* genl is still initialising */
+	if (!init_net.genl_sock)
 		return 0;
 
 	switch (event) {
 	case CTRL_CMD_NEWFAMILY:
 	case CTRL_CMD_DELFAMILY:
-		msg = ctrl_build_family_msg(data, 0, 0, event);
-		if (IS_ERR(msg))
-			return PTR_ERR(msg);
-
-		genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+		family = data;
+		msg = ctrl_build_family_msg(family, 0, 0, event);
 		break;
 	case CTRL_CMD_NEWMCAST_GRP:
 	case CTRL_CMD_DELMCAST_GRP:
+		grp = data;
+		family = grp->family;
 		msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
-		if (IS_ERR(msg))
-			return PTR_ERR(msg);
-
-		genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
 		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
+
+	if (!family->netnsok) {
+		genlmsg_multicast_netns(&init_net, msg, 0,
+					GENL_ID_CTRL, GFP_KERNEL);
+	} else {
+		rcu_read_lock();
+		genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
+		rcu_read_unlock();
 	}
 
 	return 0;
@@ -795,6 +843,33 @@ static struct genl_multicast_group notif
 	.name		= "notify",
 };
 
+static int __net_init genl_pernet_init(struct net *net)
+{
+	/* we'll bump the group number right afterwards */
+	net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
+					       genl_rcv, &genl_mutex,
+					       THIS_MODULE);
+
+	if (!net->genl_sock && net_eq(net, &init_net))
+		panic("GENL: Cannot initialize generic netlink\n");
+
+	if (!net->genl_sock)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void __net_exit genl_pernet_exit(struct net *net)
+{
+	netlink_kernel_release(net->genl_sock);
+	net->genl_sock = NULL;
+}
+
+static struct pernet_operations genl_pernet_ops = {
+	.init = genl_pernet_init,
+	.exit = genl_pernet_exit,
+};
+
 static int __init genl_init(void)
 {
 	int i, err;
@@ -804,36 +879,67 @@ static int __init genl_init(void)
 
 	err = genl_register_family(&genl_ctrl);
 	if (err < 0)
-		goto errout;
+		goto problem;
 
 	err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
 	if (err < 0)
-		goto errout_register;
+		goto problem;
 
 	netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
 
-	/* we'll bump the group number right afterwards */
-	genl_sock = netlink_kernel_create(&init_net, NETLINK_GENERIC, 0,
-					  genl_rcv, &genl_mutex, THIS_MODULE);
-	if (genl_sock == NULL)
-		panic("GENL: Cannot initialize generic netlink\n");
+	err = register_pernet_subsys(&genl_pernet_ops);
+	if (err)
+		goto problem;
 
 	err = genl_register_mc_group(&genl_ctrl, &notify_grp);
 	if (err < 0)
-		goto errout_register;
+		goto problem;
 
 	return 0;
 
-errout_register:
-	genl_unregister_family(&genl_ctrl);
-errout:
+problem:
 	panic("GENL: Cannot register controller: %d\n", err);
 }
 
 subsys_initcall(genl_init);
 
-EXPORT_SYMBOL(genl_sock);
 EXPORT_SYMBOL(genl_register_ops);
 EXPORT_SYMBOL(genl_unregister_ops);
 EXPORT_SYMBOL(genl_register_family);
 EXPORT_SYMBOL(genl_unregister_family);
+
+static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
+			 gfp_t flags)
+{
+	struct sk_buff *tmp;
+	struct net *net, *prev = NULL;
+	int err;
+
+	for_each_net_rcu(net) {
+		if (prev) {
+			tmp = skb_clone(skb, flags);
+			if (!tmp) {
+				err = -ENOMEM;
+				goto error;
+			}
+			err = nlmsg_multicast(prev->genl_sock, tmp,
+					      pid, group, flags);
+			if (err)
+				goto error;
+		}
+
+		prev = net;
+	}
+
+	return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
+ error:
+	kfree_skb(skb);
+	return err;
+}
+
+int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
+			    gfp_t flags)
+{
+	return genlmsg_mcast(skb, pid, group, flags);
+}
+EXPORT_SYMBOL(genlmsg_multicast_allns);
--- wireless-testing.orig/fs/dlm/netlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/fs/dlm/netlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -63,7 +63,7 @@ static int send_data(struct sk_buff *skb
 		return rv;
 	}
 
-	return genlmsg_unicast(skb, listener_nlpid);
+	return genlmsg_unicast(&init_net, skb, listener_nlpid);
 }
 
 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
--- wireless-testing.orig/kernel/taskstats.c	2009-07-08 14:11:56.000000000 +0200
+++ wireless-testing/kernel/taskstats.c	2009-07-08 15:01:54.000000000 +0200
@@ -108,7 +108,7 @@ static int prepare_reply(struct genl_inf
 /*
  * Send taskstats data in @skb to listener with nl_pid @pid
  */
-static int send_reply(struct sk_buff *skb, pid_t pid)
+static int send_reply(struct sk_buff *skb, struct genl_info *info)
 {
 	struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
 	void *reply = genlmsg_data(genlhdr);
@@ -120,7 +120,7 @@ static int send_reply(struct sk_buff *sk
 		return rc;
 	}
 
-	return genlmsg_unicast(skb, pid);
+	return genlmsg_reply(skb, info);
 }
 
 /*
@@ -150,7 +150,7 @@ static void send_cpu_listeners(struct sk
 			if (!skb_next)
 				break;
 		}
-		rc = genlmsg_unicast(skb_cur, s->pid);
+		rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
 		if (rc == -ECONNREFUSED) {
 			s->valid = 0;
 			delcount++;
@@ -418,7 +418,7 @@ static int cgroupstats_user_cmd(struct s
 		goto err;
 	}
 
-	rc = send_reply(rep_skb, info->snd_pid);
+	rc = send_reply(rep_skb, info);
 
 err:
 	fput_light(file, fput_needed);
@@ -487,7 +487,7 @@ free_return_rc:
 	} else
 		goto err;
 
-	return send_reply(rep_skb, info->snd_pid);
+	return send_reply(rep_skb, info);
 err:
 	nlmsg_free(rep_skb);
 	return rc;
--- wireless-testing.orig/net/irda/irnetlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/irda/irnetlink.c	2009-07-08 15:01:54.000000000 +0200
@@ -115,7 +115,7 @@ static int irda_nl_get_mode(struct sk_bu
 
 	genlmsg_end(msg, hdr);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  err_out:
 	nlmsg_free(msg);
--- wireless-testing.orig/net/netfilter/ipvs/ip_vs_ctl.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/netfilter/ipvs/ip_vs_ctl.c	2009-07-08 15:01:55.000000000 +0200
@@ -3231,7 +3231,7 @@ static int ip_vs_genl_get_cmd(struct sk_
 	}
 
 	genlmsg_end(msg, reply);
-	ret = genlmsg_unicast(msg, info->snd_pid);
+	ret = genlmsg_reply(msg, info);
 	goto out;
 
 nla_put_failure:
--- wireless-testing.orig/net/tipc/netlink.c	2009-07-08 14:11:55.000000000 +0200
+++ wireless-testing/net/tipc/netlink.c	2009-07-08 15:01:55.000000000 +0200
@@ -62,7 +62,7 @@ static int handle_cmd(struct sk_buff *sk
 		rep_nlh = nlmsg_hdr(rep_buf);
 		memcpy(rep_nlh, req_nlh, hdr_space);
 		rep_nlh->nlmsg_len = rep_buf->len;
-		genlmsg_unicast(rep_buf, NETLINK_CB(skb).pid);
+		genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).pid);
 	}
 
 	return 0;
--- wireless-testing.orig/net/wireless/nl80211.c	2009-07-08 14:12:35.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c	2009-07-08 15:01:55.000000000 +0200
@@ -596,7 +596,7 @@ static int nl80211_get_wiphy(struct sk_b
 
 	cfg80211_unlock_rdev(dev);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  out_free:
 	nlmsg_free(msg);
@@ -922,7 +922,7 @@ static int nl80211_get_interface(struct 
 	dev_put(netdev);
 	cfg80211_unlock_rdev(dev);
 
-	return genlmsg_unicast(msg, info->snd_pid);
+	return genlmsg_reply(msg, info);
 
  out_free:
 	nlmsg_free(msg);
@@ -1236,7 +1236,7 @@ static int nl80211_get_key(struct sk_buf
 		goto nla_put_failure;
 
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  nla_put_failure:
@@ -1811,7 +1811,7 @@ static int nl80211_get_station(struct sk
 				 dev, mac_addr, &sinfo) < 0)
 		goto out_free;
 
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  out_free:
@@ -2280,7 +2280,7 @@ static int nl80211_get_mpath(struct sk_b
 				 dev, dst, next_hop, &pinfo) < 0)
 		goto out_free;
 
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  out_free:
@@ -2629,7 +2629,7 @@ static int nl80211_get_mesh_params(struc
 			cur_params.dot11MeshHWMPnetDiameterTraversalTime);
 	nla_nest_end(msg, pinfoattr);
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
  nla_put_failure:
@@ -2817,7 +2817,7 @@ static int nl80211_get_reg(struct sk_buf
 	nla_nest_end(msg, nl_reg_rules);
 
 	genlmsg_end(msg, hdr);
-	err = genlmsg_unicast(msg, info->snd_pid);
+	err = genlmsg_reply(msg, info);
 	goto out;
 
 nla_put_failure:
--- wireless-testing.orig/include/net/net_namespace.h	2009-07-08 15:01:53.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-08 15:01:55.000000000 +0200
@@ -26,6 +26,7 @@ struct net_device;
 struct sock;
 struct ctl_table_header;
 struct net_generic;
+struct sock;
 
 struct net {
 	atomic_t		count;		/* To decided when the network
@@ -57,6 +58,7 @@ struct net {
 	spinlock_t		rules_mod_lock;
 
 	struct sock 		*rtnl;			/* rtnetlink socket */
+	struct sock		*genl_sock;
 
 	struct netns_core	core;
 	struct netns_mib	mib;

-- 

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[PATCH 4/4] net: move and export get_net_ns_by_pid

[Johannes Berg]

The function get_net_ns_by_pid(), to get a network
namespace from a pid_t, will be required in cfg80211
as well. Therefore, let's move it to net_namespace.c
and export it. We can't make it a static inline in
the !NETNS case because it needs to verify that the
given pid even exists (and return -ESRCH).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 include/net/net_namespace.h |    2 ++
 net/core/net_namespace.c    |   21 +++++++++++++++++++++
 net/core/rtnetlink.c        |   21 +--------------------
 3 files changed, 24 insertions(+), 20 deletions(-)

--- wireless-testing.orig/include/net/net_namespace.h	2009-07-07 12:18:30.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-07 12:25:42.000000000 +0200
@@ -111,6 +111,8 @@ static inline struct net *copy_net_ns(un
 
 extern struct list_head net_namespace_list;
 
+extern struct net *get_net_ns_by_pid(pid_t pid);
+
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
 
--- wireless-testing.orig/net/core/net_namespace.c	2009-07-07 12:18:19.000000000 +0200
+++ wireless-testing/net/core/net_namespace.c	2009-07-07 12:25:42.000000000 +0200
@@ -7,6 +7,7 @@
 #include <linux/sched.h>
 #include <linux/idr.h>
 #include <linux/rculist.h>
+#include <linux/nsproxy.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -201,6 +202,26 @@ struct net *copy_net_ns(unsigned long fl
 }
 #endif
 
+struct net *get_net_ns_by_pid(pid_t pid)
+{
+	struct task_struct *tsk;
+	struct net *net;
+
+	/* Lookup the network namespace */
+	net = ERR_PTR(-ESRCH);
+	rcu_read_lock();
+	tsk = find_task_by_vpid(pid);
+	if (tsk) {
+		struct nsproxy *nsproxy;
+		nsproxy = task_nsproxy(tsk);
+		if (nsproxy)
+			net = get_net(nsproxy->net_ns);
+	}
+	rcu_read_unlock();
+	return net;
+}
+EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
--- wireless-testing.orig/net/core/rtnetlink.c	2009-07-07 12:15:29.000000000 +0200
+++ wireless-testing/net/core/rtnetlink.c	2009-07-07 12:25:42.000000000 +0200
@@ -35,7 +35,6 @@
 #include <linux/security.h>
 #include <linux/mutex.h>
 #include <linux/if_addr.h>
-#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -52,6 +51,7 @@
 #include <net/pkt_sched.h>
 #include <net/fib_rules.h>
 #include <net/rtnetlink.h>
+#include <net/net_namespace.h>
 
 struct rtnl_link
 {
@@ -725,25 +725,6 @@ static const struct nla_policy ifla_info
 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
 };
 
-static struct net *get_net_ns_by_pid(pid_t pid)
-{
-	struct task_struct *tsk;
-	struct net *net;
-
-	/* Lookup the network namespace */
-	net = ERR_PTR(-ESRCH);
-	rcu_read_lock();
-	tsk = find_task_by_vpid(pid);
-	if (tsk) {
-		struct nsproxy *nsproxy;
-		nsproxy = task_nsproxy(tsk);
-		if (nsproxy)
-			net = get_net(nsproxy->net_ns);
-	}
-	rcu_read_unlock();
-	return net;
-}
-
 static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
 {
 	if (dev) {

-- 

[PATCH 4/4] net: move and export get_net_ns_by_pid

[Johannes Berg]

[-- Attachment #1: 030-netns-export-get-by-pid.patch --]
[-- Type: text/plain, Size: 2903 bytes --]

The function get_net_ns_by_pid(), to get a network
namespace from a pid_t, will be required in cfg80211
as well. Therefore, let's move it to net_namespace.c
and export it. We can't make it a static inline in
the !NETNS case because it needs to verify that the
given pid even exists (and return -ESRCH).

Signed-off-by: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
---
 include/net/net_namespace.h |    2 ++
 net/core/net_namespace.c    |   21 +++++++++++++++++++++
 net/core/rtnetlink.c        |   21 +--------------------
 3 files changed, 24 insertions(+), 20 deletions(-)

--- wireless-testing.orig/include/net/net_namespace.h	2009-07-07 12:18:30.000000000 +0200
+++ wireless-testing/include/net/net_namespace.h	2009-07-07 12:25:42.000000000 +0200
@@ -111,6 +111,8 @@ static inline struct net *copy_net_ns(un
 
 extern struct list_head net_namespace_list;
 
+extern struct net *get_net_ns_by_pid(pid_t pid);
+
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
 
--- wireless-testing.orig/net/core/net_namespace.c	2009-07-07 12:18:19.000000000 +0200
+++ wireless-testing/net/core/net_namespace.c	2009-07-07 12:25:42.000000000 +0200
@@ -7,6 +7,7 @@
 #include <linux/sched.h>
 #include <linux/idr.h>
 #include <linux/rculist.h>
+#include <linux/nsproxy.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -201,6 +202,26 @@ struct net *copy_net_ns(unsigned long fl
 }
 #endif
 
+struct net *get_net_ns_by_pid(pid_t pid)
+{
+	struct task_struct *tsk;
+	struct net *net;
+
+	/* Lookup the network namespace */
+	net = ERR_PTR(-ESRCH);
+	rcu_read_lock();
+	tsk = find_task_by_vpid(pid);
+	if (tsk) {
+		struct nsproxy *nsproxy;
+		nsproxy = task_nsproxy(tsk);
+		if (nsproxy)
+			net = get_net(nsproxy->net_ns);
+	}
+	rcu_read_unlock();
+	return net;
+}
+EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
--- wireless-testing.orig/net/core/rtnetlink.c	2009-07-07 12:15:29.000000000 +0200
+++ wireless-testing/net/core/rtnetlink.c	2009-07-07 12:25:42.000000000 +0200
@@ -35,7 +35,6 @@
 #include <linux/security.h>
 #include <linux/mutex.h>
 #include <linux/if_addr.h>
-#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -52,6 +51,7 @@
 #include <net/pkt_sched.h>
 #include <net/fib_rules.h>
 #include <net/rtnetlink.h>
+#include <net/net_namespace.h>
 
 struct rtnl_link
 {
@@ -725,25 +725,6 @@ static const struct nla_policy ifla_info
 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
 };
 
-static struct net *get_net_ns_by_pid(pid_t pid)
-{
-	struct task_struct *tsk;
-	struct net *net;
-
-	/* Lookup the network namespace */
-	net = ERR_PTR(-ESRCH);
-	rcu_read_lock();
-	tsk = find_task_by_vpid(pid);
-	if (tsk) {
-		struct nsproxy *nsproxy;
-		nsproxy = task_nsproxy(tsk);
-		if (nsproxy)
-			net = get_net(nsproxy->net_ns);
-	}
-	rcu_read_unlock();
-	return net;
-}

Re: [PATCH 0/4] generic netlink namespace awareness

[David Miller]

From: Johannes Berg <johannes@sipsolutions.net>
Date: Fri, 10 Jul 2009 21:51:31 +0200

> This patch series makes generic netlink network namespace
> aware, in some way, paving the way for making wireless
> completely netns aware (which I will submit to John's tree).
> 
> The required changes are basically some preparations in
> core netlink, a change to make it possible to iterate net
> namespaces under just RCU (which may be useful elsewhere in
> the future), the actual genetlink patch and finally also
> exporting get_net_ns_by_pid() which wireless will need.
> 
> The last patch (for get_net_ns_by_pid) could go through
> the wireless tree as well, but I've put it in here since
> it touches core code. The others probably shouldn't go
> through the wireless tree since they touch more than that.
> 
> The first patch in this series fixes the last remaining
> problem I had with the generic netlink one, the patches
> are actually unchanged from the previous submission other
> than adding patch 1 in front.

Looks good, all applied, thanks!

Re: [PATCH 0/4] generic netlink namespace awareness

[David Miller]

From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Date: Fri, 10 Jul 2009 21:51:31 +0200

> This patch series makes generic netlink network namespace
> aware, in some way, paving the way for making wireless
> completely netns aware (which I will submit to John's tree).
> 
> The required changes are basically some preparations in
> core netlink, a change to make it possible to iterate net
> namespaces under just RCU (which may be useful elsewhere in
> the future), the actual genetlink patch and finally also
> exporting get_net_ns_by_pid() which wireless will need.
> 
> The last patch (for get_net_ns_by_pid) could go through
> the wireless tree as well, but I've put it in here since
> it touches core code. The others probably shouldn't go
> through the wireless tree since they touch more than that.
> 
> The first patch in this series fixes the last remaining
> problem I had with the generic netlink one, the patches
> are actually unchanged from the previous submission other
> than adding patch 1 in front.

Looks good, all applied, thanks!
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