netfilter: ipset: Log warning when a hash type of set gets full

If the set is full, the SET target cannot add more elements.
Log warning so that the admin got notified about it.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 18 insertions, 4 deletions

diff --git a/include/linux/netfilter/ipset/ip_set_ahash.h b/include/linux/netfilter/ipset/ip_set_ahash.h
index b89fb79cb44f..bd1fc8d16851 100644
--- a/include/linux/netfilter/ipset/ip_set_ahash.h
+++ b/include/linux/netfilter/ipset/ip_set_ahash.h
@@ -353,9 +353,12 @@ retry:
         htable_bits++;
         pr_debug("attempt to resize set %s from %u to %u, t %p\n",
                  set->name, orig->htable_bits, htable_bits, orig);
-        if (!htable_bits)
+        if (!htable_bits) {
                 /* In case we have plenty of memory :-) */
+                pr_warning("Cannot increase the hashsize of set %s further\n",
+                           set->name);
                 return -IPSET_ERR_HASH_FULL;
+        }
         t = ip_set_alloc(sizeof(*t)
                          + jhash_size(htable_bits) * sizeof(struct hbucket));
         if (!t)
@@ -407,8 +410,12 @@ type_pf_add(struct ip_set *set, void *value, u32 timeout, u32 flags)
         int i, ret = 0;
         u32 key, multi = 0;
 
-        if (h->elements >= h->maxelem)
+        if (h->elements >= h->maxelem) {
+                if (net_ratelimit())
+                        pr_warning("Set %s is full, maxelem %u reached\n",
+                                   set->name, h->maxelem);
                 return -IPSET_ERR_HASH_FULL;
+        }
 
         rcu_read_lock_bh();
         t = rcu_dereference_bh(h->table);
@@ -790,9 +797,12 @@ type_pf_tresize(struct ip_set *set, bool retried)
 retry:
         ret = 0;
         htable_bits++;
-        if (!htable_bits)
+        if (!htable_bits) {
                 /* In case we have plenty of memory :-) */
+                pr_warning("Cannot increase the hashsize of set %s further\n",
+                           set->name);
                 return -IPSET_ERR_HASH_FULL;
+        }
         t = ip_set_alloc(sizeof(*t)
                          + jhash_size(htable_bits) * sizeof(struct hbucket));
         if (!t)
@@ -843,8 +853,12 @@ type_pf_tadd(struct ip_set *set, void *value, u32 timeout, u32 flags)
         if (h->elements >= h->maxelem)
                 /* FIXME: when set is full, we slow down here */
                 type_pf_expire(h);
-        if (h->elements >= h->maxelem)
+        if (h->elements >= h->maxelem) {
+                if (net_ratelimit())
+                        pr_warning("Set %s is full, maxelem %u reached\n",
+                                   set->name, h->maxelem);
                 return -IPSET_ERR_HASH_FULL;
+        }
 
         rcu_read_lock_bh();
         t = rcu_dereference_bh(h->table);