1 files changed, 225 insertions, 4 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 41eabc46f110..456b11b0f049 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -35,6 +35,10 @@
 
 #include "xfrm_hash.h"
 
+#define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
+#define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
+#define XFRM_MAX_QUEUE_LEN      100
+
 DEFINE_MUTEX(xfrm_cfg_mutex);
 EXPORT_SYMBOL(xfrm_cfg_mutex);
 
@@ -51,7 +55,7 @@ static struct kmem_cache *xfrm_dst_cache __read_mostly;
 static void xfrm_init_pmtu(struct dst_entry *dst);
 static int stale_bundle(struct dst_entry *dst);
 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
-
+static void xfrm_policy_queue_process(unsigned long arg);
 
 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
                                                 int dir);
@@ -287,8 +291,11 @@ struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
                 INIT_HLIST_NODE(&policy->byidx);
                 rwlock_init(&policy->lock);
                 atomic_set(&policy->refcnt, 1);
+                skb_queue_head_init(&policy->polq.hold_queue);
                 setup_timer(&policy->timer, xfrm_policy_timer,
                                 (unsigned long)policy);
+                setup_timer(&policy->polq.hold_timer, xfrm_policy_queue_process,
+                            (unsigned long)policy);
                 policy->flo.ops = &xfrm_policy_fc_ops;
         }
         return policy;
@@ -309,6 +316,16 @@ void xfrm_policy_destroy(struct xfrm_policy *policy)
 }
 EXPORT_SYMBOL(xfrm_policy_destroy);
 
+static void xfrm_queue_purge(struct sk_buff_head *list)
+{
+        struct sk_buff *skb;
+
+        while ((skb = skb_dequeue(list)) != NULL) {
+                dev_put(skb->dev);
+                kfree_skb(skb);
+        }
+}
+
 /* Rule must be locked. Release descentant resources, announce
  * entry dead. The rule must be unlinked from lists to the moment.
  */
@@ -319,6 +336,9 @@ static void xfrm_policy_kill(struct xfrm_policy *policy)
 
         atomic_inc(&policy->genid);
 
+        del_timer(&policy->polq.hold_timer);
+        xfrm_queue_purge(&policy->polq.hold_queue);
+
         if (del_timer(&policy->timer))
                 xfrm_pol_put(policy);
 
@@ -562,6 +582,31 @@ static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s
         return 0;
 }
 
+static void xfrm_policy_requeue(struct xfrm_policy *old,
+                                struct xfrm_policy *new)
+{
+        struct xfrm_policy_queue *pq = &old->polq;
+        struct sk_buff_head list;
+
+        __skb_queue_head_init(&list);
+
+        spin_lock_bh(&pq->hold_queue.lock);
+        skb_queue_splice_init(&pq->hold_queue, &list);
+        del_timer(&pq->hold_timer);
+        spin_unlock_bh(&pq->hold_queue.lock);
+
+        if (skb_queue_empty(&list))
+                return;
+
+        pq = &new->polq;
+
+        spin_lock_bh(&pq->hold_queue.lock);
+        skb_queue_splice(&list, &pq->hold_queue);
+        pq->timeout = XFRM_QUEUE_TMO_MIN;
+        mod_timer(&pq->hold_timer, jiffies);
+        spin_unlock_bh(&pq->hold_queue.lock);
+}
+
 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 {
         struct net *net = xp_net(policy);
@@ -603,8 +648,10 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
         net->xfrm.policy_count[dir]++;
         atomic_inc(&flow_cache_genid);
         rt_genid_bump(net);
-        if (delpol)
+        if (delpol) {
+                xfrm_policy_requeue(delpol, policy);
                 __xfrm_policy_unlink(delpol, dir);
+        }
         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
         policy->curlft.add_time = get_seconds();
@@ -1115,11 +1162,15 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
         }
-        if (old_pol)
+        if (old_pol) {
+                if (pol)
+                        xfrm_policy_requeue(old_pol, pol);
+
                 /* Unlinking succeeds always. This is the only function
                  * allowed to delete or replace socket policy.
                  */
                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
+        }
         write_unlock_bh(&xfrm_policy_lock);
 
         if (old_pol) {
@@ -1310,6 +1361,8 @@ static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *f
                  * It means we need to try again resolving. */
                 if (xdst->num_xfrms > 0)
                         return NULL;
+        } else if (dst->flags & DST_XFRM_QUEUE) {
+                return NULL;
         } else {
                 /* Real bundle */
                 if (stale_bundle(dst))
@@ -1673,6 +1726,171 @@ xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
         return xdst;
 }
 
+static void xfrm_policy_queue_process(unsigned long arg)
+{
+        int err = 0;
+        struct sk_buff *skb;
+        struct sock *sk;
+        struct dst_entry *dst;
+        struct net_device *dev;
+        struct xfrm_policy *pol = (struct xfrm_policy *)arg;
+        struct xfrm_policy_queue *pq = &pol->polq;
+        struct flowi fl;
+        struct sk_buff_head list;
+
+        spin_lock(&pq->hold_queue.lock);
+        skb = skb_peek(&pq->hold_queue);
+        dst = skb_dst(skb);
+        sk = skb->sk;
+        xfrm_decode_session(skb, &fl, dst->ops->family);
+        spin_unlock(&pq->hold_queue.lock);
+
+        dst_hold(dst->path);
+        dst = xfrm_lookup(xp_net(pol), dst->path, &fl,
+                          sk, 0);
+        if (IS_ERR(dst))
+                goto purge_queue;
+
+        if (dst->flags & DST_XFRM_QUEUE) {
+                dst_release(dst);
+
+                if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
+                        goto purge_queue;
+
+                pq->timeout = pq->timeout << 1;
+                mod_timer(&pq->hold_timer, jiffies + pq->timeout);
+                return;
+        }
+
+        dst_release(dst);
+
+        __skb_queue_head_init(&list);
+
+        spin_lock(&pq->hold_queue.lock);
+        pq->timeout = 0;
+        skb_queue_splice_init(&pq->hold_queue, &list);
+        spin_unlock(&pq->hold_queue.lock);
+
+        while (!skb_queue_empty(&list)) {
+                skb = __skb_dequeue(&list);
+
+                xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
+                dst_hold(skb_dst(skb)->path);
+                dst = xfrm_lookup(xp_net(pol), skb_dst(skb)->path,
+                                  &fl, skb->sk, 0);
+                if (IS_ERR(dst)) {
+                        dev_put(skb->dev);
+                        kfree_skb(skb);
+                        continue;
+                }
+
+                nf_reset(skb);
+                skb_dst_drop(skb);
+                skb_dst_set(skb, dst);
+
+                dev = skb->dev;
+                err = dst_output(skb);
+                dev_put(dev);
+        }
+
+        return;
+
+purge_queue:
+        pq->timeout = 0;
+        xfrm_queue_purge(&pq->hold_queue);
+}
+
+static int xdst_queue_output(struct sk_buff *skb)
+{
+        unsigned long sched_next;
+        struct dst_entry *dst = skb_dst(skb);
+        struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
+        struct xfrm_policy_queue *pq = &xdst->pols[0]->polq;
+
+        if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
+                kfree_skb(skb);
+                return -EAGAIN;
+        }
+
+        skb_dst_force(skb);
+        dev_hold(skb->dev);
+
+        spin_lock_bh(&pq->hold_queue.lock);
+
+        if (!pq->timeout)
+                pq->timeout = XFRM_QUEUE_TMO_MIN;
+
+        sched_next = jiffies + pq->timeout;
+
+        if (del_timer(&pq->hold_timer)) {
+                if (time_before(pq->hold_timer.expires, sched_next))
+                        sched_next = pq->hold_timer.expires;
+        }
+
+        __skb_queue_tail(&pq->hold_queue, skb);
+        mod_timer(&pq->hold_timer, sched_next);
+
+        spin_unlock_bh(&pq->hold_queue.lock);
+
+        return 0;
+}
+
+static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
+                                                 struct dst_entry *dst,
+                                                 const struct flowi *fl,
+                                                 int num_xfrms,
+                                                 u16 family)
+{
+        int err;
+        struct net_device *dev;
+        struct dst_entry *dst1;
+        struct xfrm_dst *xdst;
+
+        xdst = xfrm_alloc_dst(net, family);
+        if (IS_ERR(xdst))
+                return xdst;
+
+        if (net->xfrm.sysctl_larval_drop || num_xfrms <= 0 ||
+            (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP))
+                return xdst;
+
+        dst1 = &xdst->u.dst;
+        dst_hold(dst);
+        xdst->route = dst;
+
+        dst_copy_metrics(dst1, dst);
+
+        dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
+        dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
+        dst1->lastuse = jiffies;
+
+        dst1->input = dst_discard;
+        dst1->output = xdst_queue_output;
+
+        dst_hold(dst);
+        dst1->child = dst;
+        dst1->path = dst;
+
+        xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
+
+        err = -ENODEV;
+        dev = dst->dev;
+        if (!dev)
+                goto free_dst;
+
+        err = xfrm_fill_dst(xdst, dev, fl);
+        if (err)
+                goto free_dst;
+
+out:
+        return xdst;
+
+free_dst:
+        dst_release(dst1);
+        xdst = ERR_PTR(err);
+        goto out;
+}
+
 static struct flow_cache_object *
 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
                    struct flow_cache_object *oldflo, void *ctx)
@@ -1751,7 +1969,7 @@ make_dummy_bundle:
         /* We found policies, but there's no bundles to instantiate:
          * either because the policy blocks, has no transformations or
          * we could not build template (no xfrm_states).*/
-        xdst = xfrm_alloc_dst(net, family);
+        xdst = xfrm_create_dummy_bundle(net, dst_orig, fl, num_xfrms, family);
         if (IS_ERR(xdst)) {
                 xfrm_pols_put(pols, num_pols);
                 return ERR_CAST(xdst);
@@ -2359,6 +2577,9 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
             (dst->dev && !netif_running(dst->dev)))
                 return 0;
 
+        if (dst->flags & DST_XFRM_QUEUE)
+                return 1;
+
         last = NULL;
 
         do {