[patch 37/38][IPV6] ndisc - dynamically allocate default neigh_parms for ndisc

[Daniel Lezcano]

This patch dynamically allocates default neigh_parms for IPv6 network 
discovery and store them in struct net. That provides the basic changes 
needed to support ndisc for multiple network namespaces.

Signed-off-by: Benjamin Thery <benjamin.thery at bull.net>
Signed-off-by: Daniel Lezcano <dlezcano at fr.ibm.com>
---
 include/net/net_namespace.h |    3 +++
 net/ipv6/ndisc.c            |   38 +++++++++++++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 7 deletions(-)

Index: linux-2.6-netns/include/net/net_namespace.h
===================================================================
--- linux-2.6-netns.orig/include/net/net_namespace.h
+++ linux-2.6-netns/include/net/net_namespace.h
@@ -83,6 +83,9 @@ struct net {
 	unsigned int		fib_info_hash_size;
 	unsigned int		fib_info_cnt;
 	struct hlist_head	*fib_info_devhash;
+
+ 	/* IPv6 ndisc.c */
+ 	struct neigh_parms	*ndisc_neigh_parms_default;
 };
 
 #ifdef CONFIG_NET
Index: linux-2.6-netns/net/ipv6/ndisc.c
===================================================================
--- linux-2.6-netns.orig/net/ipv6/ndisc.c
+++ linux-2.6-netns/net/ipv6/ndisc.c
@@ -1764,23 +1764,47 @@ int __init ndisc_init(struct net_proto_f
 
 	neigh_table_init(&nd_tbl);
 
+	init_net.ndisc_neigh_parms_default =
+		neigh_parms_alloc_default(&nd_tbl, &init_net);
+	if (!init_net.ndisc_neigh_parms_default) {
+		err = -ENOMEM;
+		goto out_neigh_parms;
+	}
+
 #ifdef CONFIG_SYSCTL
-	neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH,
-			      "ipv6",
-			      &ndisc_ifinfo_sysctl_change,
-			      &ndisc_ifinfo_sysctl_strategy);
+	if ((err = neigh_sysctl_register(NULL,
+					 init_net.ndisc_neigh_parms_default,
+					 NET_IPV6, NET_IPV6_NEIGH,
+					 "ipv6",
+					 &ndisc_ifinfo_sysctl_change,
+					 &ndisc_ifinfo_sysctl_strategy)))
+	     goto out_sysctl;
 #endif
-
 	register_netdevice_notifier(&ndisc_netdev_notifier);
-	return 0;
+out:
+	return err;
+#ifdef CONFIG_SYSCTL
+out_sysctl:
+	neigh_parms_release(&nd_tbl, init_net.ndisc_neigh_parms_default);
+#endif
+out_neigh_parms:
+	sock_release(ndisc_socket);
+	goto out;
 }
 
 void ndisc_cleanup(void)
 {
+	struct neigh_parms *parms = init_net.ndisc_neigh_parms_default;
+
 	unregister_netdevice_notifier(&ndisc_netdev_notifier);
+
+	if (parms) {
 #ifdef CONFIG_SYSCTL
-	neigh_sysctl_unregister(&nd_tbl.parms);
+		neigh_sysctl_unregister(parms);
 #endif
+		neigh_parms_release(&nd_tbl, parms);
+		init_net.ndisc_neigh_parms_default = NULL;
+	}
 	neigh_table_clear(&nd_tbl);
 	sock_release(ndisc_socket);
 	ndisc_socket = NULL; /* For safety. */

--