Commit 421842ed authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net/ipv6: Add fib6_null_entry 



ip6_null_entry will stay a dst based return for lookups that fail to
match an entry.

Add a new fib6_null_entry which constitutes the root node and leafs
for fibs. Replace existing references to ip6_null_entry with the
new fib6_null_entry when dealing with FIBs.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 14895687

include/net/netns/ipv6.h

+2 −1
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ struct netns_ipv6 { 
#endif

	struct xt_table		*ip6table_nat;

#endif

	struct rt6_info         *fib6_null_entry;

	struct rt6_info		*ip6_null_entry;

	struct rt6_statistics   *rt6_stats;

	struct timer_list       ip6_fib_timer;

net/ipv6/ip6_fib.c

+13 −13
Original line number Diff line number Diff line
@@ -231,7 +231,7 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 
	if (table) {

		table->tb6_id = id;

		rcu_assign_pointer(table->tb6_root.leaf,

				   net->ipv6.ip6_null_entry);

				   net->ipv6.fib6_null_entry);

		table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;

		inet_peer_base_init(&table->tb6_peers);

	}
@@ -369,7 +369,7 @@ struct fib6_dump_arg { 


static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg)

{

	if (rt == arg->net->ipv6.ip6_null_entry)

	if (rt == arg->net->ipv6.fib6_null_entry)

		return;

	call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);

}
@@ -658,7 +658,7 @@ static struct fib6_node *fib6_add_1(struct net *net, 
			/* remove null_entry in the root node */

			} else if (fn->fn_flags & RTN_TL_ROOT &&

				   rcu_access_pointer(fn->leaf) ==

				   net->ipv6.ip6_null_entry) {

				   net->ipv6.fib6_null_entry) {

				RCU_INIT_POINTER(fn->leaf, NULL);

			}
@@ -1171,9 +1171,9 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, 
			if (!sfn)

				goto failure;



			atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);

			atomic_inc(&info->nl_net->ipv6.fib6_null_entry->rt6i_ref);

			rcu_assign_pointer(sfn->leaf,

					   info->nl_net->ipv6.ip6_null_entry);

					   info->nl_net->ipv6.fib6_null_entry);

			sfn->fn_flags = RTN_ROOT;



			/* Now add the first leaf node to new subtree */
@@ -1212,7 +1212,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, 
			if (fn->fn_flags & RTN_TL_ROOT) {

				/* put back null_entry for root node */

				rcu_assign_pointer(fn->leaf,

					    info->nl_net->ipv6.ip6_null_entry);

					    info->nl_net->ipv6.fib6_null_entry);

			} else {

				atomic_inc(&rt->rt6i_ref);

				rcu_assign_pointer(fn->leaf, rt);
@@ -1251,7 +1251,7 @@ out: 
				if (!pn_leaf) {

					WARN_ON(!pn_leaf);

					pn_leaf =

					    info->nl_net->ipv6.ip6_null_entry;

					    info->nl_net->ipv6.fib6_null_entry;

				}

#endif

				atomic_inc(&pn_leaf->rt6i_ref);
@@ -1494,7 +1494,7 @@ static struct rt6_info *fib6_find_prefix(struct net *net, 
	struct fib6_node *child_left, *child_right;



	if (fn->fn_flags & RTN_ROOT)

		return net->ipv6.ip6_null_entry;

		return net->ipv6.fib6_null_entry;



	while (fn) {

		child_left = rcu_dereference_protected(fn->left,
@@ -1531,7 +1531,7 @@ static struct fib6_node *fib6_repair_tree(struct net *net, 


	/* Set fn->leaf to null_entry for root node. */

	if (fn->fn_flags & RTN_TL_ROOT) {

		rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry);

		rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);

		return fn;

	}
@@ -1576,7 +1576,7 @@ static struct fib6_node *fib6_repair_tree(struct net *net, 
#if RT6_DEBUG >= 2

			if (!new_fn_leaf) {

				WARN_ON(!new_fn_leaf);

				new_fn_leaf = net->ipv6.ip6_null_entry;

				new_fn_leaf = net->ipv6.fib6_null_entry;

			}

#endif

			atomic_inc(&new_fn_leaf->rt6i_ref);
@@ -1726,7 +1726,7 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info) 
		return -ENOENT;

	}

#endif

	if (!fn || rt == net->ipv6.ip6_null_entry)

	if (!fn || rt == net->ipv6.fib6_null_entry)

		return -ENOENT;



	WARN_ON(!(fn->fn_flags & RTN_RTINFO));
@@ -2087,7 +2087,7 @@ static int __net_init fib6_net_init(struct net *net) 


	net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;

	rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,

			   net->ipv6.ip6_null_entry);

			   net->ipv6.fib6_null_entry);

	net->ipv6.fib6_main_tbl->tb6_root.fn_flags =

		RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;

	inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
@@ -2099,7 +2099,7 @@ static int __net_init fib6_net_init(struct net *net) 
		goto out_fib6_main_tbl;

	net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;

	rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,

			   net->ipv6.ip6_null_entry);

			   net->ipv6.fib6_null_entry);

	net->ipv6.fib6_local_tbl->tb6_root.fn_flags =

		RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;

	inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);

net/ipv6/route.c

+43 −19
Original line number Diff line number Diff line
@@ -276,6 +276,15 @@ static const u32 ip6_template_metrics[RTAX_MAX] = { 
	[RTAX_HOPLIMIT - 1] = 0,

};



static const struct rt6_info fib6_null_entry_template = {

	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),

	.rt6i_protocol  = RTPROT_KERNEL,

	.rt6i_metric	= ~(u32)0,

	.rt6i_ref	= ATOMIC_INIT(1),

	.fib6_type	= RTN_UNREACHABLE,

	.fib6_metrics	= (struct dst_metrics *)&dst_default_metrics,

};



static const struct rt6_info ip6_null_entry_template = {

	.dst = {

		.__refcnt	= ATOMIC_INIT(1),
@@ -522,10 +531,10 @@ static inline struct rt6_info *rt6_device_match(struct net *net, 
			return local;



		if (flags & RT6_LOOKUP_F_IFACE)

			return net->ipv6.ip6_null_entry;

			return net->ipv6.fib6_null_entry;

	}



	return rt->fib6_nh.nh_flags & RTNH_F_DEAD ? net->ipv6.ip6_null_entry : rt;

	return rt->fib6_nh.nh_flags & RTNH_F_DEAD ? net->ipv6.fib6_null_entry : rt;

}



#ifdef CONFIG_IPV6_ROUTER_PREF
@@ -758,8 +767,8 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, 
	bool do_rr = false;

	int key_plen;



	if (!leaf || leaf == net->ipv6.ip6_null_entry)

		return net->ipv6.ip6_null_entry;

	if (!leaf || leaf == net->ipv6.fib6_null_entry)

		return net->ipv6.fib6_null_entry;



	rt0 = rcu_dereference(fn->rr_ptr);

	if (!rt0)
@@ -776,7 +785,7 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, 
		key_plen = rt0->rt6i_src.plen;

#endif

	if (fn->fn_bit != key_plen)

		return net->ipv6.ip6_null_entry;

		return net->ipv6.fib6_null_entry;



	match = find_rr_leaf(fn, leaf, rt0, rt0->rt6i_metric, oif, strict,

			     &do_rr);
@@ -797,7 +806,7 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, 
		}

	}



	return match ? match : net->ipv6.ip6_null_entry;

	return match ? match : net->ipv6.fib6_null_entry;

}



static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt)
@@ -1063,7 +1072,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net, 
restart:

	rt = rcu_dereference(fn->leaf);

	if (!rt) {

		rt = net->ipv6.ip6_null_entry;

		rt = net->ipv6.fib6_null_entry;

	} else {

		rt = rt6_device_match(net, rt, &fl6->saddr,

				      fl6->flowi6_oif, flags);
@@ -1071,7 +1080,7 @@ restart: 
			rt = rt6_multipath_select(net, rt, fl6, fl6->flowi6_oif,

						  skb, flags);

	}

	if (rt == net->ipv6.ip6_null_entry) {

	if (rt == net->ipv6.fib6_null_entry) {

		fn = fib6_backtrack(fn, &fl6->saddr);

		if (fn)

			goto restart;
@@ -1820,7 +1829,7 @@ redo_rt6_select: 
	rt = rt6_select(net, fn, oif, strict);

	if (rt->rt6i_nsiblings)

		rt = rt6_multipath_select(net, rt, fl6, oif, skb, strict);

	if (rt == net->ipv6.ip6_null_entry) {

	if (rt == net->ipv6.fib6_null_entry) {

		fn = fib6_backtrack(fn, &fl6->saddr);

		if (fn)

			goto redo_rt6_select;
@@ -1837,7 +1846,8 @@ redo_rt6_select: 
	if (rt_cache)

		rt = rt_cache;



	if (rt == net->ipv6.ip6_null_entry) {

	if (rt == net->ipv6.fib6_null_entry) {

		rt = net->ipv6.ip6_null_entry;

		rcu_read_unlock();

		dst_hold(&rt->dst);

		trace_fib6_table_lookup(net, rt, table, fl6);
@@ -2412,13 +2422,13 @@ restart: 
	}



	if (!rt)

		rt = net->ipv6.ip6_null_entry;

		rt = net->ipv6.fib6_null_entry;

	else if (rt->rt6i_flags & RTF_REJECT) {

		rt = net->ipv6.ip6_null_entry;

		goto out;

	}



	if (rt == net->ipv6.ip6_null_entry) {

	if (rt == net->ipv6.fib6_null_entry) {

		fn = fib6_backtrack(fn, &fl6->saddr);

		if (fn)

			goto restart;
@@ -3051,7 +3061,7 @@ static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info) 
	struct fib6_table *table;

	int err;



	if (rt == net->ipv6.ip6_null_entry) {

	if (rt == net->ipv6.fib6_null_entry) {

		err = -ENOENT;

		goto out;

	}
@@ -3081,7 +3091,7 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg) 
	struct fib6_table *table;

	int err = -ENOENT;



	if (rt == net->ipv6.ip6_null_entry)

	if (rt == net->ipv6.fib6_null_entry)

		goto out_put;

	table = rt->rt6i_table;

	spin_lock_bh(&table->tb6_lock);
@@ -3634,7 +3644,7 @@ static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg) 
	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;



	if (((void *)rt->fib6_nh.nh_dev == dev || !dev) &&

	    rt != net->ipv6.ip6_null_entry &&

	    rt != net->ipv6.fib6_null_entry &&

	    ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {

		spin_lock_bh(&rt6_exception_lock);

		/* remove prefsrc entry */
@@ -3789,7 +3799,7 @@ static int fib6_ifup(struct rt6_info *rt, void *p_arg) 
	const struct arg_netdev_event *arg = p_arg;

	struct net *net = dev_net(arg->dev);



	if (rt != net->ipv6.ip6_null_entry && rt->fib6_nh.nh_dev == arg->dev) {

	if (rt != net->ipv6.fib6_null_entry && rt->fib6_nh.nh_dev == arg->dev) {

		rt->fib6_nh.nh_flags &= ~arg->nh_flags;

		fib6_update_sernum_upto_root(net, rt);

		rt6_multipath_rebalance(rt);
@@ -3873,7 +3883,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg) 
	const struct net_device *dev = arg->dev;

	struct net *net = dev_net(dev);



	if (rt == net->ipv6.ip6_null_entry)

	if (rt == net->ipv6.fib6_null_entry)

		return 0;



	switch (arg->event) {
@@ -4624,7 +4634,7 @@ int rt6_dump_route(struct rt6_info *rt, void *p_arg) 
	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;

	struct net *net = arg->net;



	if (rt == net->ipv6.ip6_null_entry)

	if (rt == net->ipv6.fib6_null_entry)

		return 0;



	if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
@@ -4813,6 +4823,8 @@ static int ip6_route_dev_notify(struct notifier_block *this, 
		return NOTIFY_OK;



	if (event == NETDEV_REGISTER) {

		net->ipv6.fib6_null_entry->fib6_nh.nh_dev = dev;

		net->ipv6.fib6_null_entry->rt6i_idev = in6_dev_get(dev);

		net->ipv6.ip6_null_entry->dst.dev = dev;

		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
@@ -4826,6 +4838,7 @@ static int ip6_route_dev_notify(struct notifier_block *this, 
		/* NETDEV_UNREGISTER could be fired for multiple times by

		 * netdev_wait_allrefs(). Make sure we only call this once.

		 */

		in6_dev_put_clear(&net->ipv6.fib6_null_entry->rt6i_idev);

		in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);

#ifdef CONFIG_IPV6_MULTIPLE_TABLES

		in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
@@ -5009,11 +5022,17 @@ static int __net_init ip6_route_net_init(struct net *net) 
	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)

		goto out_ip6_dst_ops;



	net->ipv6.fib6_null_entry = kmemdup(&fib6_null_entry_template,

					    sizeof(*net->ipv6.fib6_null_entry),

					    GFP_KERNEL);

	if (!net->ipv6.fib6_null_entry)

		goto out_ip6_dst_entries;



	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,

					   sizeof(*net->ipv6.ip6_null_entry),

					   GFP_KERNEL);

	if (!net->ipv6.ip6_null_entry)

		goto out_ip6_dst_entries;

		goto out_fib6_null_entry;

	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;

	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,

			 ip6_template_metrics, true);
@@ -5060,6 +5079,8 @@ out_ip6_prohibit_entry: 
out_ip6_null_entry:

	kfree(net->ipv6.ip6_null_entry);

#endif

out_fib6_null_entry:

	kfree(net->ipv6.fib6_null_entry);

out_ip6_dst_entries:

	dst_entries_destroy(&net->ipv6.ip6_dst_ops);

out_ip6_dst_ops:
@@ -5068,6 +5089,7 @@ out_ip6_dst_ops: 


static void __net_exit ip6_route_net_exit(struct net *net)

{

	kfree(net->ipv6.fib6_null_entry);

	kfree(net->ipv6.ip6_null_entry);

#ifdef CONFIG_IPV6_MULTIPLE_TABLES

	kfree(net->ipv6.ip6_prohibit_entry);
@@ -5138,6 +5160,8 @@ void __init ip6_route_init_special_entries(void) 
	/* Registering of the loopback is done before this portion of code,

	 * the loopback reference in rt6_info will not be taken, do it

	 * manually for init_net */

	init_net.ipv6.fib6_null_entry->fib6_nh.nh_dev = init_net.loopback_dev;

	init_net.ipv6.fib6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);

	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;

	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);

  #ifdef CONFIG_IPV6_MULTIPLE_TABLES

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