1 files changed, 87 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index e6ff7b4046ea..55bcb8604bc6 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -566,6 +566,86 @@ static void xfrm_hash_resize(struct work_struct *work)
         mutex_unlock(&hash_resize_mutex);
 }
 
+static void xfrm_hash_rebuild(struct work_struct *work)
+{
+        struct net *net = container_of(work, struct net,
+                                       xfrm.policy_hthresh.work);
+        unsigned int hmask;
+        struct xfrm_policy *pol;
+        struct xfrm_policy *policy;
+        struct hlist_head *chain;
+        struct hlist_head *odst;
+        struct hlist_node *newpos;
+        int i;
+        int dir;
+        unsigned seq;
+        u8 lbits4, rbits4, lbits6, rbits6;
+
+        mutex_lock(&hash_resize_mutex);
+
+        /* read selector prefixlen thresholds */
+        do {
+                seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
+
+                lbits4 = net->xfrm.policy_hthresh.lbits4;
+                rbits4 = net->xfrm.policy_hthresh.rbits4;
+                lbits6 = net->xfrm.policy_hthresh.lbits6;
+                rbits6 = net->xfrm.policy_hthresh.rbits6;
+        } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
+
+        write_lock_bh(&net->xfrm.xfrm_policy_lock);
+
+        /* reset the bydst and inexact table in all directions */
+        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
+                INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
+                hmask = net->xfrm.policy_bydst[dir].hmask;
+                odst = net->xfrm.policy_bydst[dir].table;
+                for (i = hmask; i >= 0; i--)
+                        INIT_HLIST_HEAD(odst + i);
+                if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
+                        /* dir out => dst = remote, src = local */
+                        net->xfrm.policy_bydst[dir].dbits4 = rbits4;
+                        net->xfrm.policy_bydst[dir].sbits4 = lbits4;
+                        net->xfrm.policy_bydst[dir].dbits6 = rbits6;
+                        net->xfrm.policy_bydst[dir].sbits6 = lbits6;
+                } else {
+                        /* dir in/fwd => dst = local, src = remote */
+                        net->xfrm.policy_bydst[dir].dbits4 = lbits4;
+                        net->xfrm.policy_bydst[dir].sbits4 = rbits4;
+                        net->xfrm.policy_bydst[dir].dbits6 = lbits6;
+                        net->xfrm.policy_bydst[dir].sbits6 = rbits6;
+                }
+        }
+
+        /* re-insert all policies by order of creation */
+        list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
+                newpos = NULL;
+                chain = policy_hash_bysel(net, &policy->selector,
+                                          policy->family,
+                                          xfrm_policy_id2dir(policy->index));
+                hlist_for_each_entry(pol, chain, bydst) {
+                        if (policy->priority >= pol->priority)
+                                newpos = &pol->bydst;
+                        else
+                                break;
+                }
+                if (newpos)
+                        hlist_add_behind(&policy->bydst, newpos);
+                else
+                        hlist_add_head(&policy->bydst, chain);
+        }
+
+        write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+
+        mutex_unlock(&hash_resize_mutex);
+}
+
+void xfrm_policy_hash_rebuild(struct net *net)
+{
+        schedule_work(&net->xfrm.policy_hthresh.work);
+}
+EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
+
 /* 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, u32 index)
@@ -2872,9 +2952,16 @@ static int __net_init xfrm_policy_init(struct net *net)
                 htab->dbits6 = 128;
                 htab->sbits6 = 128;
         }
+        net->xfrm.policy_hthresh.lbits4 = 32;
+        net->xfrm.policy_hthresh.rbits4 = 32;
+        net->xfrm.policy_hthresh.lbits6 = 128;
+        net->xfrm.policy_hthresh.rbits6 = 128;
+
+        seqlock_init(&net->xfrm.policy_hthresh.lock);
 
         INIT_LIST_HEAD(&net->xfrm.policy_all);
         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
+        INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
         if (net_eq(net, &init_net))
                 register_netdevice_notifier(&xfrm_dev_notifier);
         return 0;