NAT: fix maximum out of order fragments (VPP-1399)

[vpp.git] / src / plugins / nat / nat_reass.c

diff --git a/src/plugins/nat/nat_reass.c b/src/plugins/nat/nat_reass.c
index 50bfced..8fd370d 100755 (executable)
--- a/src/plugins/nat/nat_reass.c
+++ b/src/plugins/nat/nat_reass.c
@@ -228,7 +228,7 @@ nat_ip4_reass_find_or_create (ip4_address_t src, ip4_address_t dst,
   dlist_elt_t *oldest_elt, *elt;
   dlist_elt_t *per_reass_list_head_elt;
   u32 oldest_index, elt_index;
-  clib_bihash_kv_16_8_t kv;
+  clib_bihash_kv_16_8_t kv, value;
 
   k.src.as_u32 = src.as_u32;
   k.dst.as_u32 = dst.as_u32;
@@ -249,6 +249,13 @@ nat_ip4_reass_find_or_create (ip4_address_t src, ip4_address_t dst,
                              srm->ip4_reass_head_index,
                              reass->lru_list_index);
        }
+
+      if (reass->flags && NAT_REASS_FLAG_MAX_FRAG_DROP)
+       {
+         reass = 0;
+         goto unlock;
+       }
+
       goto unlock;
     }
 
@@ -273,12 +280,18 @@ nat_ip4_reass_find_or_create (ip4_address_t src, ip4_address_t dst,
       clib_dlist_addtail (srm->ip4_reass_lru_list_pool,
                          srm->ip4_reass_head_index, oldest_index);
 
-      kv.key[0] = k.as_u64[0];
-      kv.key[1] = k.as_u64[1];
-      if (clib_bihash_add_del_16_8 (&srm->ip4_reass_hash, &kv, 0))
+      kv.key[0] = reass->key.as_u64[0];
+      kv.key[1] = reass->key.as_u64[1];
+      if (!clib_bihash_search_16_8 (&srm->ip4_reass_hash, &kv, &value))
        {
-         reass = 0;
-         goto unlock;
+         if (value.value == (reass - srm->ip4_reass_pool))
+           {
+             if (clib_bihash_add_del_16_8 (&srm->ip4_reass_hash, &kv, 0))
+               {
+                 reass = 0;
+                 goto unlock;
+               }
+           }
        }
 
       nat_ip4_reass_get_frags_inline (reass, bi_to_drop);
@@ -320,7 +333,8 @@ unlock:
 }
 
 int
-nat_ip4_reass_add_fragment (nat_reass_ip4_t * reass, u32 bi)
+nat_ip4_reass_add_fragment (nat_reass_ip4_t * reass, u32 bi,
+                           u32 ** bi_to_drop)
 {
   nat_reass_main_t *srm = &nat_reass_main;
   dlist_elt_t *elt;
@@ -330,6 +344,8 @@ nat_ip4_reass_add_fragment (nat_reass_ip4_t * reass, u32 bi)
     {
       nat_ipfix_logging_max_fragments_ip4 (srm->ip4_max_frag,
                                           &reass->key.src);
+      reass->flags |= NAT_REASS_FLAG_MAX_FRAG_DROP;
+      nat_ip4_reass_get_frags_inline (reass, bi_to_drop);
       return -1;
     }
 
@@ -440,6 +456,13 @@ nat_ip6_reass_find_or_create (ip6_address_t src, ip6_address_t dst,
                              srm->ip6_reass_head_index,
                              reass->lru_list_index);
        }
+
+      if (reass->flags && NAT_REASS_FLAG_MAX_FRAG_DROP)
+       {
+         reass = 0;
+         goto unlock;
+       }
+
       goto unlock;
     }
 
@@ -516,7 +539,8 @@ unlock:
 }
 
 int
-nat_ip6_reass_add_fragment (nat_reass_ip6_t * reass, u32 bi)
+nat_ip6_reass_add_fragment (nat_reass_ip6_t * reass, u32 bi,
+                           u32 ** bi_to_drop)
 {
   nat_reass_main_t *srm = &nat_reass_main;
   dlist_elt_t *elt;
@@ -526,6 +550,8 @@ nat_ip6_reass_add_fragment (nat_reass_ip6_t * reass, u32 bi)
     {
       nat_ipfix_logging_max_fragments_ip6 (srm->ip6_max_frag,
                                           &reass->key.src);
+      reass->flags |= NAT_REASS_FLAG_MAX_FRAG_DROP;
+      nat_ip6_reass_get_frags_inline (reass, bi_to_drop);
       return -1;
     }