ipv4: Make neigh lookups directly in output packet path.
Do not use the dst cached neigh, we'll be getting rid of that.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index d81d026..a793af9 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -474,8 +474,8 @@
}
EXPORT_SYMBOL(neigh_lookup_nodev);
-struct neighbour *neigh_create(struct neigh_table *tbl, const void *pkey,
- struct net_device *dev)
+struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
+ struct net_device *dev, bool want_ref)
{
u32 hash_val;
int key_len = tbl->key_len;
@@ -535,14 +535,16 @@
n1 = rcu_dereference_protected(n1->next,
lockdep_is_held(&tbl->lock))) {
if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
- neigh_hold(n1);
+ if (want_ref)
+ neigh_hold(n1);
rc = n1;
goto out_tbl_unlock;
}
}
n->dead = 0;
- neigh_hold(n);
+ if (want_ref)
+ neigh_hold(n);
rcu_assign_pointer(n->next,
rcu_dereference_protected(nht->hash_buckets[hash_val],
lockdep_is_held(&tbl->lock)));
@@ -558,7 +560,7 @@
neigh_release(n);
goto out;
}
-EXPORT_SYMBOL(neigh_create);
+EXPORT_SYMBOL(__neigh_create);
static u32 pneigh_hash(const void *pkey, int key_len)
{
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 2630900..6e9a266 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -170,6 +170,7 @@
struct net_device *dev = dst->dev;
unsigned int hh_len = LL_RESERVED_SPACE(dev);
struct neighbour *neigh;
+ u32 nexthop;
if (rt->rt_type == RTN_MULTICAST) {
IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len);
@@ -191,15 +192,18 @@
skb = skb2;
}
- rcu_read_lock();
- neigh = dst_get_neighbour_noref(dst);
+ rcu_read_lock_bh();
+ nexthop = rt->rt_gateway ? rt->rt_gateway : ip_hdr(skb)->daddr;
+ neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
+ if (unlikely(!neigh))
+ neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
if (neigh) {
int res = neigh_output(neigh, skb);
- rcu_read_unlock();
+ rcu_read_unlock_bh();
return res;
}
- rcu_read_unlock();
+ rcu_read_unlock_bh();
net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
__func__);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6a5afc7..2f40363 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1098,17 +1098,13 @@
static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
{
- static const __be32 inaddr_any = 0;
struct net_device *dev = dst->dev;
const __be32 *pkey = daddr;
const struct rtable *rt;
struct neighbour *n;
rt = (const struct rtable *) dst;
-
- if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
- pkey = &inaddr_any;
- else if (rt->rt_gateway)
+ if (rt->rt_gateway)
pkey = (const __be32 *) &rt->rt_gateway;
n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);