[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 061a7bba163a3294d3cf39926cefd89a8e1c54ed..6a4019a4ca89d0f875062d1b36c282be9d4feb3c 100644 (file)
--- 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 @@ if (rt == &ip6_null_entry && strict) { \
 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 @@ restart:
        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;
+       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_hold(&rt->u.dst);
-               if (nrt) {
-                       err = ip6_ins_rt(nrt, NULL, NULL,
-                                        &NETLINK_CB(skb));
-                       if (!err)
-                               goto out2;
-               }
+       dst_release(&rt->u.dst);
+       rt = nrt ? : &ip6_null_entry;
 
-               if (--attempts <= 0)
+       dst_hold(&rt->u.dst);
+       if (nrt) {
+               err = ip6_ins_rt(nrt, NULL, NULL, &NETLINK_CB(skb));
+               if (!err)
                        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 (--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 @@ restart:
        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);
+       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;
-               }
+       dst_release(&rt->u.dst);
+       rt = nrt ? : &ip6_null_entry;
 
-               if (--attempts <= 0)
+       dst_hold(&rt->u.dst);
+       if (nrt) {
+               err = ip6_ins_rt(nrt, NULL, NULL, NULL);
+               if (!err)
                        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 (--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;
 }