Question about CONFIG_IPV6_SUBTREES

Yan Zheng
2005-10-10T01:26:14Z

Hi all

In ip6_fib.c, fib6_lookup_1() does't make sense to me with
CONFIG_IPV6_SUBTREES enable. It seem to only match source address when
fib6_node has subtree. So I write a patch to show my opinion.
unfortunately, this changes don't cooperate with BACKTRACK() in route.c.

Can somebody explain the exact meaning of CONFIG_IPV6_SUBTREES!

Thanks.

--- linux-2.6.14-rc3-git8/net/ipv6/ip6_fib.c 2005-10-10
08:57:40.000000000 +0800
+++ linux/net/ipv6/ip6_fib.c 2005-10-10 08:53:44.000000000 +0800
@@ -616,21 +616,6 @@
}

while ((fn->fn_flags & RTN_ROOT) == 0) {
-#ifdef CONFIG_IPV6_SUBTREES
- if (fn->subtree) {
- struct fib6_node *st;
- struct lookup_args *narg;
-
- narg = args + 1;
-
- if (narg->addr) {
- st = fib6_lookup_1(fn->subtree, narg);
-
- if (st && !(st->fn_flags & RTN_ROOT))
- return st;
- }
- }
-#endif

if (fn->fn_flags & RTN_RTINFO) {
struct rt6key *key;
@@ -639,7 +624,24 @@
args->offset);

if (ipv6_prefix_equal(&key->addr, args->addr,
key->plen))
- return fn;
+#ifdef CONFIG_IPV6_SUBTREES
+ if (fn->subtree) {
+ struct fib6_node *st;
+ struct lookup_args *narg;
+
+ narg = args + 1;
+
+ if (narg->addr) {
+ st =
fib6_lookup_1(fn->subtree, narg);
+
+ if (st && !(st->fn_flags
& RTN_ROOT))
+ return st;
+ if (fn->subtree->leaf !=
&ip6_null_entry)
+ return fn->subtree;
+ }
+ } else
+#endif
+ return fn;
}

fn = fn->parent;