Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.

This patch updates all of the existing netlink protocols
to only support the initial network namespace.  Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.

As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.

The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 drivers/connector/connector.c       |    2 +-
 drivers/scsi/scsi_netlink.c         |    2 +-
 drivers/scsi/scsi_transport_iscsi.c |    2 +-
 fs/ecryptfs/netlink.c               |    2 +-
 include/linux/netlink.h             |    6 ++-
 kernel/audit.c                      |    4 +-
 lib/kobject_uevent.c                |    5 +-
 net/bridge/netfilter/ebt_ulog.c     |    5 +-
 net/core/rtnetlink.c                |    4 +-
 net/decnet/netfilter/dn_rtmsg.c     |    3 +-
 net/ipv4/fib_frontend.c             |    4 +-
 net/ipv4/inet_diag.c                |    4 +-
 net/ipv4/netfilter/ip_queue.c       |    6 +-
 net/ipv4/netfilter/ipt_ULOG.c       |    3 +-
 net/ipv6/netfilter/ip6_queue.c      |    6 +-
 net/netfilter/nfnetlink.c           |    2 +-
 net/netfilter/nfnetlink_log.c       |    3 +-
 net/netfilter/nfnetlink_queue.c     |    3 +-
 net/netlink/af_netlink.c            |  106 ++++++++++++++++++++++++++---------
 net/netlink/genetlink.c             |    4 +-
 net/xfrm/xfrm_user.c                |    2 +-
 security/selinux/netlink.c          |    5 +-
 22 files changed, 122 insertions(+), 61 deletions(-)

diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index a7b9e9b..5690709 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -446,7 +446,7 @@ static int __devinit cn_init(void)
 	dev->id.idx = cn_idx;
 	dev->id.val = cn_val;
 
-	dev->nls = netlink_kernel_create(NETLINK_CONNECTOR,
+	dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR,
 					 CN_NETLINK_USERS + 0xf,
 					 dev->input, NULL, THIS_MODULE);
 	if (!dev->nls)
diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c
index 4bf9aa5..163acf6 100644
--- a/drivers/scsi/scsi_netlink.c
+++ b/drivers/scsi/scsi_netlink.c
@@ -167,7 +167,7 @@ scsi_netlink_init(void)
 		return;
 	}
 
-	scsi_nl_sock = netlink_kernel_create(NETLINK_SCSITRANSPORT,
+	scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
 				SCSI_NL_GRP_CNT, scsi_nl_rcv, NULL,
 				THIS_MODULE);
 	if (!scsi_nl_sock) {
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 34c1860..4916f01 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1523,7 +1523,7 @@ static __init int iscsi_transport_init(void)
 	if (err)
 		goto unregister_conn_class;
 
-	nls = netlink_kernel_create(NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
+	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
 			THIS_MODULE);
 	if (!nls) {
 		err = -ENOBUFS;
diff --git a/fs/ecryptfs/netlink.c b/fs/ecryptfs/netlink.c
index fe91863..056519c 100644
--- a/fs/ecryptfs/netlink.c
+++ b/fs/ecryptfs/netlink.c
@@ -227,7 +227,7 @@ int ecryptfs_init_netlink(void)
 {
 	int rc;
 
-	ecryptfs_nl_sock = netlink_kernel_create(NETLINK_ECRYPTFS, 0,
+	ecryptfs_nl_sock = netlink_kernel_create(&init_net, NETLINK_ECRYPTFS, 0,
 						 ecryptfs_receive_nl_message,
 						 NULL, THIS_MODULE);
 	if (!ecryptfs_nl_sock) {
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 83d8239..d2843ae 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -27,6 +27,8 @@
 
 #define MAX_LINKS 32		
 
+struct net;
+
 struct sockaddr_nl
 {
 	sa_family_t	nl_family;	/* AF_NETLINK	*/
@@ -157,7 +159,8 @@ struct netlink_skb_parms
 #define NETLINK_CREDS(skb)	(&NETLINK_CB((skb)).creds)
 
 
-extern struct sock *netlink_kernel_create(int unit, unsigned int groups,
+extern struct sock *netlink_kernel_create(struct net *net,
+					  int unit,unsigned int groups,
 					  void (*input)(struct sock *sk, int len),
 					  struct mutex *cb_mutex,
 					  struct module *module);
@@ -206,6 +209,7 @@ struct netlink_callback
 
 struct netlink_notify
 {
+	struct net *net;
 	int pid;
 	int protocol;
 };
diff --git a/kernel/audit.c b/kernel/audit.c
index eb0f916..f3c390f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -876,8 +876,8 @@ static int __init audit_init(void)
 
 	printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
 	       audit_default ? "enabled" : "disabled");
-	audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive,
-					   NULL, THIS_MODULE);
+	audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
+					   audit_receive, NULL, THIS_MODULE);
 	if (!audit_sock)
 		audit_panic("cannot initialize netlink socket");
 	else
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index df02814..e06a8dc 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -280,9 +280,8 @@ EXPORT_SYMBOL_GPL(add_uevent_var);
 #if defined(CONFIG_NET)
 static int __init kobject_uevent_init(void)
 {
-	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
-					    NULL, THIS_MODULE);
-
+	uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,
+					    1, NULL, NULL, THIS_MODULE);
 	if (!uevent_sock) {
 		printk(KERN_ERR
 		       "kobject_uevent: unable to create netlink socket!\n");
diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c
index 204c968..e7cfd30 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -300,8 +300,9 @@ static int __init ebt_ulog_init(void)
 		spin_lock_init(&ulog_buffers[i].lock);
 	}
 
-	ebtulognl = netlink_kernel_create(NETLINK_NFLOG, EBT_ULOG_MAXNLGROUPS,
-					  NULL, NULL, THIS_MODULE);
+	ebtulognl = netlink_kernel_create(&init_net, NETLINK_NFLOG,
+					  EBT_ULOG_MAXNLGROUPS, NULL, NULL,
+					  THIS_MODULE);
 	if (!ebtulognl)
 		ret = -ENOMEM;
 	else if ((ret = ebt_register_watcher(&ulog)))
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4185950..416768d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1327,8 +1327,8 @@ void __init rtnetlink_init(void)
 	if (!rta_buf)
 		panic("rtnetlink_init: cannot allocate rta_buf\n");
 
-	rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
-				     &rtnl_mutex, THIS_MODULE);
+	rtnl = netlink_kernel_create(&init_net, NETLINK_ROUTE, RTNLGRP_MAX,
+				     rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
 	if (rtnl == NULL)
 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index 6962346..ebb38fe 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -137,7 +137,8 @@ static int __init dn_rtmsg_init(void)
 {
 	int rv = 0;
 
-	dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
+	dnrmg = netlink_kernel_create(&init_net,
+				      NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
 				      dnrmg_receive_user_sk, NULL, THIS_MODULE);
 	if (dnrmg == NULL) {
 		printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index cefb55e..140bf7a 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -816,8 +816,8 @@ static void nl_fib_input(struct sock *sk, int len)
 
 static void nl_fib_lookup_init(void)
 {
-      netlink_kernel_create(NETLINK_FIB_LOOKUP, 0, nl_fib_input, NULL,
-			    THIS_MODULE);
+	netlink_kernel_create(&init_net, NETLINK_FIB_LOOKUP, 0, nl_fib_input,
+				NULL, THIS_MODULE);
 }
 
 static void fib_disable_ip(struct net_device *dev, int force)
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 06922da..169026d 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -893,8 +893,8 @@ static int __init inet_diag_init(void)
 	if (!inet_diag_table)
 		goto out;
 
-	idiagnl = netlink_kernel_create(NETLINK_INET_DIAG, 0, inet_diag_rcv,
-					NULL, THIS_MODULE);
+	idiagnl = netlink_kernel_create(&init_net, NETLINK_INET_DIAG, 0,
+					inet_diag_rcv, NULL, THIS_MODULE);
 	if (idiagnl == NULL)
 		goto out_free_table;
 	err = 0;
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index d918560..82fda92 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -579,7 +579,7 @@ ipq_rcv_nl_event(struct notifier_block *this,
 	if (event == NETLINK_URELEASE &&
 	    n->protocol == NETLINK_FIREWALL && n->pid) {
 		write_lock_bh(&queue_lock);
-		if (n->pid == peer_pid)
+		if ((n->net == &init_net) && (n->pid == peer_pid))
 			__ipq_reset();
 		write_unlock_bh(&queue_lock);
 	}
@@ -671,8 +671,8 @@ static int __init ip_queue_init(void)
 	struct proc_dir_entry *proc;
 
 	netlink_register_notifier(&ipq_nl_notifier);
-	ipqnl = netlink_kernel_create(NETLINK_FIREWALL, 0, ipq_rcv_sk,
-				      NULL, THIS_MODULE);
+	ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
+				      ipq_rcv_sk, NULL, THIS_MODULE);
 	if (ipqnl == NULL) {
 		printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 		goto cleanup_netlink_notifier;
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 6ca43e4..c636d6d 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -409,7 +409,8 @@ static int __init ipt_ulog_init(void)
 	for (i = 0; i < ULOG_MAXNLGROUPS; i++)