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: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f6ca55d..7c14139 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
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 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
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 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
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 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
}
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 @@ static int __net_init ip6_route_net_init(struct net *net)
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 @@ static int __net_init ip6_route_net_init(struct net *net)
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