[IPV6]: ROUTE: Clean-up cow'ing in ip6_route_{intput,output}().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 061a7bb..6a4019a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -72,6 +72,7 @@
#define RT6_TRACE(x...) do { ; } while (0)
#endif
+#define CLONE_OFFLINK_ROUTE 0
static int ip6_rt_max_size = 4096;
static int ip6_rt_gc_min_interval = HZ / 2;
@@ -465,9 +466,10 @@
void ip6_route_input(struct sk_buff *skb)
{
struct fib6_node *fn;
- struct rt6_info *rt;
+ struct rt6_info *rt, *nrt;
int strict;
int attempts = 3;
+ int err;
strict = ipv6_addr_type(&skb->nh.ipv6h->daddr) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL);
@@ -492,51 +494,53 @@
dst_hold(&rt->u.dst);
read_unlock_bh(&rt6_lock);
- if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) {
- struct rt6_info *nrt;
- int err;
-
- nrt = rt6_alloc_cow(rt, &skb->nh.ipv6h->daddr,
- &skb->nh.ipv6h->saddr);
-
- dst_release(&rt->u.dst);
- rt = nrt ? : &ip6_null_entry;
-
- dst_hold(&rt->u.dst);
- if (nrt) {
- err = ip6_ins_rt(nrt, NULL, NULL,
- &NETLINK_CB(skb));
- if (!err)
- goto out2;
- }
-
- if (--attempts <= 0)
- goto out2;
-
- /* Race condition! In the gap, when rt6_lock was
- released someone could insert this route. Relookup.
- */
- dst_release(&rt->u.dst);
- goto relookup;
+ if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
+ nrt = rt6_alloc_cow(rt, &skb->nh.ipv6h->daddr, &skb->nh.ipv6h->saddr);
+ else {
+#if CLONE_OFFLINK_ROUTE
+ nrt = rt6_alloc_clone(rt, &skb->nh.ipv6h->daddr);
+#else
+ goto out2;
+#endif
}
+ dst_release(&rt->u.dst);
+ rt = nrt ? : &ip6_null_entry;
+
+ dst_hold(&rt->u.dst);
+ if (nrt) {
+ err = ip6_ins_rt(nrt, NULL, NULL, &NETLINK_CB(skb));
+ if (!err)
+ goto out2;
+ }
+
+ if (--attempts <= 0)
+ goto out2;
+
+ /*
+ * Race condition! In the gap, when rt6_lock was
+ * released someone could insert this route. Relookup.
+ */
+ dst_release(&rt->u.dst);
+ goto relookup;
+
+out:
+ dst_hold(&rt->u.dst);
+ read_unlock_bh(&rt6_lock);
out2:
rt->u.dst.lastuse = jiffies;
rt->u.dst.__use++;
skb->dst = (struct dst_entry *) rt;
return;
-out:
- dst_hold(&rt->u.dst);
- read_unlock_bh(&rt6_lock);
- goto out2;
}
struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl)
{
struct fib6_node *fn;
- struct rt6_info *rt;
+ struct rt6_info *rt, *nrt;
int strict;
int attempts = 3;
+ int err;
strict = ipv6_addr_type(&fl->fl6_dst) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL);
@@ -564,40 +568,43 @@
dst_hold(&rt->u.dst);
read_unlock_bh(&rt6_lock);
- if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) {
- struct rt6_info *nrt;
- int err;
-
+ if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src);
-
- dst_release(&rt->u.dst);
- rt = nrt ? : &ip6_null_entry;
-
- dst_hold(&rt->u.dst);
- if (nrt) {
- err = ip6_ins_rt(nrt, NULL, NULL, NULL);
- if (!err)
- goto out2;
- }
-
- if (--attempts <= 0)
- goto out2;
-
- /* Race condition! In the gap, when rt6_lock was
- released someone could insert this route. Relookup.
- */
- dst_release(&rt->u.dst);
- goto relookup;
+ else {
+#if CLONE_OFFLINK_ROUTE
+ nrt = rt6_alloc_clone(rt, &fl->fl6_dst);
+#else
+ goto out2;
+#endif
}
+ dst_release(&rt->u.dst);
+ rt = nrt ? : &ip6_null_entry;
+
+ dst_hold(&rt->u.dst);
+ if (nrt) {
+ err = ip6_ins_rt(nrt, NULL, NULL, NULL);
+ if (!err)
+ goto out2;
+ }
+
+ if (--attempts <= 0)
+ goto out2;
+
+ /*
+ * Race condition! In the gap, when rt6_lock was
+ * released someone could insert this route. Relookup.
+ */
+ dst_release(&rt->u.dst);
+ goto relookup;
+
+out:
+ dst_hold(&rt->u.dst);
+ read_unlock_bh(&rt6_lock);
out2:
rt->u.dst.lastuse = jiffies;
rt->u.dst.__use++;
return &rt->u.dst;
-out:
- dst_hold(&rt->u.dst);
- read_unlock_bh(&rt6_lock);
- goto out2;
}