xfrm: Try to honor policy index if it's supplied by user
xfrm code always searches for unused policy index for
newly created policy regardless whether or not user
space policy index hint supplied.
This patch enables such feature so that using
"ip xfrm ... index=xxx" can be used by user to set
specific policy index.
Currently this beahvior is broken, so this patch make
it happen as expected.
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 9a91f74..a5bbdfb 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -538,7 +538,7 @@
/* Generate new index... KAME seems to generate them ordered by cost
* of an absolute inpredictability of ordering of rules. This will not pass. */
-static u32 xfrm_gen_index(struct net *net, int dir)
+static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
{
static u32 idx_generator;
@@ -548,8 +548,14 @@
u32 idx;
int found;
- idx = (idx_generator | dir);
- idx_generator += 8;
+ if (!index) {
+ idx = (idx_generator | dir);
+ idx_generator += 8;
+ } else {
+ idx = index;
+ index = 0;
+ }
+
if (idx == 0)
idx = 8;
list = net->xfrm.policy_byidx + idx_hash(net, idx);
@@ -672,7 +678,7 @@
xfrm_policy_requeue(delpol, policy);
__xfrm_policy_unlink(delpol, dir);
}
- policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
+ policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
policy->curlft.add_time = get_seconds();
policy->curlft.use_time = 0;
@@ -1192,7 +1198,7 @@
sk->sk_policy[dir] = pol;
if (pol) {
pol->curlft.add_time = get_seconds();
- pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
+ pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
__xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
}
if (old_pol) {