[PATCH v2 net-next 10/13] neighbour: Namespacify neigh_tables.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-08-07 23:29:42
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Now, neigh_table is ready to be namespacified. Let's allocate per-netns neigh_table in neigh_table_register() and call neigh_table_init() and neigh_sysctl_register() for it. proc_create_seq_data() is changed to proc_create_net_data(). neigh_flush_one() calls timer_shutdown_sync() outside of n->lock if its netns is dying because neigh_del_timer() uses timer_delete() and there might be running timer and its neigh_release() might be executed after neigh_table_clear() frees neigh_table. The next patch will remove other unnecessary net_eq(). Note that CONFIG_SYSCTL cannot be enabled without CONFIG_PROC_FS. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- v2: * panic() when register_pernet_subsys(&arp_net_ops) fails * Add timer_shutdown_sync() in neigh_flush_one() --- include/net/neighbour.h | 2 -- net/core/neighbour.c | 45 ++++++++++++++++++++++++++++------------- net/ipv4/arp.c | 20 +++++++++++++----- net/ipv6/ndisc.c | 43 ++++++++++++++------------------------- 4 files changed, 61 insertions(+), 49 deletions(-)
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 3e31eebf8663..b4e89533e1e6 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h@@ -341,8 +341,6 @@ static inline void neigh_confirm(struct neighbour *n) int neigh_table_register(struct net *net, struct neigh_table *tbl, int index); void neigh_table_unregister(struct net *net, int index); -void neigh_table_init(struct neigh_table *tbl); -int neigh_table_clear(struct neigh_table *tbl); struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev); struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 36488dbd1512..71aadcf9626d 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c@@ -397,6 +397,9 @@ static void neigh_flush_one(struct neighbour *n) write_unlock(&n->lock); + if (!check_net(neigh_parms_net(n->parms))) + timer_shutdown_sync(&n->timer); + neigh_cleanup_and_release(n); }
@@ -1807,10 +1810,9 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms) static struct lock_class_key neigh_table_proxy_queue_class; -void neigh_table_init(struct neigh_table *tbl) +static int neigh_table_init(struct net *net, struct neigh_table *tbl) { unsigned long now = jiffies; - struct net *net = &init_net; unsigned long phsize; RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
@@ -1830,8 +1832,9 @@ void neigh_table_init(struct neigh_table *tbl) goto err_stats; #ifdef CONFIG_PROC_FS - if (!proc_create_seq_data(tbl->id, 0, net->proc_net_stat, - &neigh_stat_seq_ops, tbl)) + if (!proc_create_net_data(tbl->id, 0, net->proc_net_stat, + &neigh_stat_seq_ops, + sizeof(struct seq_net_private), tbl)) goto err_proc; #endif
@@ -1860,7 +1863,7 @@ void neigh_table_init(struct neigh_table *tbl) INIT_DEFERRABLE_WORK(&tbl->managed_work, neigh_managed_work); queue_delayed_work(system_power_efficient_wq, &tbl->managed_work, 0); - return; + return 0; #ifdef CONFIG_PROC_FS err_proc:
@@ -1871,16 +1874,11 @@ void neigh_table_init(struct neigh_table *tbl) err_phash: neigh_hash_free_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu); err_hash: - panic("cannot allocate memory"); + return -ENOMEM; } -/* - * Only called from ndisc_cleanup(), which means this is dead code - * because we no longer can unload IPv6 module. - */ -int neigh_table_clear(struct neigh_table *tbl) +static void neigh_table_clear(struct net *net, struct neigh_table *tbl) { - struct net *net __maybe_unused = &init_net; struct neigh_hash_table *nht; cancel_delayed_work_sync(&tbl->managed_work);
@@ -1901,20 +1899,39 @@ int neigh_table_clear(struct neigh_table *tbl) nht = rcu_dereference_protected(tbl->nht, 1); tbl->nht = NULL; neigh_hash_free_rcu(&nht->rcu); - - return 0; } int neigh_table_register(struct net *net, struct neigh_table *tbl, int index) { + int err; + + tbl = kmemdup(tbl, sizeof(*tbl), GFP_KERNEL); + if (!tbl) { + err = -ENOMEM; + goto err; + } + + err = neigh_table_init(net, tbl); + if (err) + goto free_table; + net->neigh_tables[index] = tbl; return 0; + +free_table: + kfree(tbl); +err: + return err; } void neigh_table_unregister(struct net *net, int index) { + struct neigh_table *tbl = net->neigh_tables[index]; + net->neigh_tables[index] = NULL; + neigh_table_clear(net, tbl); + kfree(tbl); } static struct neigh_table *neigh_find_table(struct net *net, int family)
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index a44fa68fdd07..f197051d3aa7 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c@@ -1518,6 +1518,12 @@ static int __net_init arp_net_init(struct net *net) goto err; #ifdef CONFIG_PROC_FS +#ifdef CONFIG_SYSCTL + err = neigh_sysctl_register(NULL, &arp_table(net)->parms, NULL); + if (err) + goto err_sysctl; +#endif + if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops, sizeof(struct neigh_seq_state))) { err = -ENOMEM;
@@ -1529,6 +1535,10 @@ static int __net_init arp_net_init(struct net *net) #ifdef CONFIG_PROC_FS err_proc_create: +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&arp_table(net)->parms); +err_sysctl: +#endif neigh_table_unregister(net, NEIGH_ARP_TABLE); #endif err:
@@ -1538,6 +1548,9 @@ static int __net_init arp_net_init(struct net *net) static void __net_exit arp_net_exit(struct net *net) { remove_proc_entry("arp", net->proc_net); +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&arp_table(net)->parms); +#endif neigh_table_unregister(net, NEIGH_ARP_TABLE); }
@@ -1548,12 +1561,9 @@ static struct pernet_operations arp_net_ops = { void __init arp_init(void) { - neigh_table_init(&arp_tbl); + if (register_pernet_subsys(&arp_net_ops)) + panic("Cannot allocate arp table\n"); dev_add_pack(&arp_packet_type); - register_pernet_subsys(&arp_net_ops); -#ifdef CONFIG_SYSCTL - neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); -#endif register_netdevice_notifier(&arp_netdev_notifier); }
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 3a458b188595..13e24c64dcdc 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c@@ -1984,6 +1984,13 @@ static int __net_init ndisc_net_init(struct net *net) if (err) goto err; +#ifdef CONFIG_SYSCTL + err = neigh_sysctl_register(NULL, &nd_table(net)->parms, + ndisc_ifinfo_sysctl_change); + if (err) + goto err_sysctl; +#endif + err = inet_ctl_sock_create(&sk, PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, net); if (err < 0) {
@@ -2002,6 +2009,10 @@ static int __net_init ndisc_net_init(struct net *net) return 0; err_sock_create: +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&nd_table(net)->parms); +err_sysctl: +#endif neigh_table_unregister(net, NEIGH_ND_TABLE); err: return err;
@@ -2010,6 +2021,9 @@ static int __net_init ndisc_net_init(struct net *net) static void __net_exit ndisc_net_exit(struct net *net) { inet_ctl_sock_destroy(net->ipv6.ndisc_sk); +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&nd_table(net)->parms); +#endif neigh_table_unregister(net, NEIGH_ND_TABLE); }
@@ -2020,30 +2034,7 @@ static struct pernet_operations ndisc_net_ops = { int __init ndisc_init(void) { - int err; - - err = register_pernet_subsys(&ndisc_net_ops); - if (err) - return err; - /* - * Initialize the neighbour table - */ - neigh_table_init(&nd_tbl); - -#ifdef CONFIG_SYSCTL - err = neigh_sysctl_register(NULL, &nd_tbl.parms, - ndisc_ifinfo_sysctl_change); - if (err) - goto out_unregister_pernet; -out: -#endif - return err; - -#ifdef CONFIG_SYSCTL -out_unregister_pernet: - unregister_pernet_subsys(&ndisc_net_ops); - goto out; -#endif + return register_pernet_subsys(&ndisc_net_ops); } int __init ndisc_late_init(void)
@@ -2058,9 +2049,5 @@ void ndisc_late_cleanup(void) void ndisc_cleanup(void) { -#ifdef CONFIG_SYSCTL - neigh_sysctl_unregister(&nd_tbl.parms); -#endif - neigh_table_clear(&nd_tbl); unregister_pernet_subsys(&ndisc_net_ops); }
--
2.55.0.679.g6767b8d81c-goog