1 files changed, 604 insertions, 5 deletions

diff --git a/src/plugins/acl/hash_lookup.c b/src/plugins/acl/hash_lookup.c
index 8c884dc997d..ea07fad7e1b 100644
--- a/src/plugins/acl/hash_lookup.c
+++ b/src/plugins/acl/hash_lookup.c
@@ -53,6 +53,268 @@ hashtable_add_del(acl_main_t *am, clib_bihash_kv_48_8_t *kv, int is_add)
     BV (clib_bihash_add_del) (&am->acl_lookup_hash, kv, is_add);
 }
 
+/*
+ * TupleMerge
+ *
+ * Initial adaptation by Valerio Bruschi (valerio.bruschi@telecom-paristech.fr)
+ * based on the TupleMerge [1] simulator kindly made available
+ * by  James Daly (dalyjamese@gmail.com) and  Eric Torng (torng@cse.msu.edu)
+ * ( http://www.cse.msu.edu/~dalyjame/ or http://www.cse.msu.edu/~torng/ ),
+ * refactoring by Andrew Yourtchenko.
+ *
+ * [1] James Daly, Eric Torng "TupleMerge: Building Online Packet Classifiers
+ * by Omitting Bits", In Proc. IEEE ICCCN 2017, pp. 1-10
+ *
+ */
+
+static int
+count_bits (u64 word)
+{
+  int counter = 0;
+  while (word)
+    {
+      counter += word & 1;
+      word >>= 1;
+    }
+  return counter;
+}
+
+/* check if mask2 can be contained by mask1 */
+static u8
+first_mask_contains_second_mask(int is_ip6, fa_5tuple_t * mask1, fa_5tuple_t * mask2)
+{
+  int i;
+  if (is_ip6)
+    {
+      for (i = 0; i < 2; i++)
+        {
+          if ((mask1->ip6_addr[0].as_u64[i] & mask2->ip6_addr[0].as_u64[i]) !=
+              mask1->ip6_addr[0].as_u64[i])
+            return 0;
+          if ((mask1->ip6_addr[1].as_u64[i] & mask2->ip6_addr[1].as_u64[i]) !=
+              mask1->ip6_addr[1].as_u64[i])
+            return 0;
+        }
+    }
+  else
+    {
+      /* check the pads, both masks must have it 0 */
+      u32 padcheck = 0;
+      int i;
+      for (i=0; i<6; i++) {
+        padcheck |= mask1->l3_zero_pad[i];
+        padcheck |= mask2->l3_zero_pad[i];
+      }
+      if (padcheck != 0)
+        return 0;
+      if ((mask1->ip4_addr[0].as_u32 & mask2->ip4_addr[0].as_u32) !=
+          mask1->ip4_addr[0].as_u32)
+        return 0;
+      if ((mask1->ip4_addr[1].as_u32 & mask2->ip4_addr[1].as_u32) !=
+          mask1->ip4_addr[1].as_u32)
+        return 0;
+    }
+
+  /* take care if port are not exact-match  */
+  if ((mask1->l4.as_u64 & mask2->l4.as_u64) != mask1->l4.as_u64)
+    return 0;
+
+  if ((mask1->pkt.as_u64 & mask2->pkt.as_u64) != mask1->pkt.as_u64)
+    return 0;
+
+  return 1;
+}
+
+
+
+/*
+ * TupleMerge:
+ *
+ * Consider the situation when we have to create a new table
+ * T for a given rule R. This occurs for the first rule inserted and
+ * for later rules if it is incompatible with all existing tables.
+ * In this event, we need to determine mT for a new table.
+ * Setting mT = mR is not a good strategy; if another similar,
+ * but slightly less specific, rule appears we will be unable to
+ * add it to T and will thus have to create another new table. We
+ * thus consider two factors: is the rule more strongly aligned
+ * with source or destination addresses (usually the two most
+ * important fields) and how much slack needs to be given to
+ * allow for other rules. If the source and destination addresses
+ * are close together (within 4 bits for our experiments), we use
+ * both of them. Otherwise, we drop the smaller (less specific)
+ * address and its associated port field from consideration; R is
+ * predominantly aligned with one of the two fields and should
+ * be grouped with other similar rules. This is similar to TSS
+ * dropping port fields, but since it is based on observable rule
+ * characteristics it is more likely to keep important fields and
+ * discard less useful ones.
+ * We then look at the absolute lengths of the addresses. If
+ * the address is long, we are more likely to try to add shorter
+ * lengths and likewise the reverse. We thus remove a few bits
+ * from both address fields with more bits removed from longer
+ * addresses. For 32 bit addresses, we remove 4 bits, 3 for more
+ * than 24, 2 for more than 16, and so on (so 8 and fewer bits
+ * don’t have any removed). We only do this for prefix fields like
+ * addresses; both range fields (like ports) and exact match fields
+ * (like protocol) should remain as they are.
+ */
+
+
+static u32
+shift_ip4_if(u32 mask, u32 thresh, int numshifts, u32 else_val)
+{
+  if (mask > thresh)
+     return clib_host_to_net_u32((clib_net_to_host_u32(mask) << numshifts) & 0xFFFFFFFF);
+  else
+     return else_val;
+}
+
+static void
+relax_ip4_addr(ip4_address_t *ip4_mask, int relax2) {
+  int shifts_per_relax[2][4] = { { 6, 5, 4, 2 }, { 3, 2, 1, 1 } };
+
+  int *shifts = shifts_per_relax[relax2];
+  if(ip4_mask->as_u32 == 0xffffffff)
+    ip4_mask->as_u32 = clib_host_to_net_u32((clib_net_to_host_u32(ip4_mask->as_u32) << shifts[0])&0xFFFFFFFF);
+  else
+    ip4_mask->as_u32 = shift_ip4_if(ip4_mask->as_u32, 0xffffff00, shifts[1],
+                        shift_ip4_if(ip4_mask->as_u32, 0xffff0000, shifts[2],
+                          shift_ip4_if(ip4_mask->as_u32, 0xff000000, shifts[3], ip4_mask->as_u32)));
+}
+
+static void
+relax_ip6_addr(ip6_address_t *ip6_mask, int relax2) {
+  /*
+   * This "better than nothing" relax logic is based on heuristics
+   * from IPv6 knowledge, and may not be optimal.
+   * Some further tuning may be needed in the future.
+   */
+  if (ip6_mask->as_u64[0] == 0xffffffffffffffffULL) {
+    if (ip6_mask->as_u64[1] == 0xffffffffffffffffULL) {
+      /* relax a /128 down to /64  - likely to have more hosts */
+      ip6_mask->as_u64[1] = 0;
+    } else if (ip6_mask->as_u64[1] == 0) {
+      /* relax a /64 down to /56 - likely to have more subnets */
+      ip6_mask->as_u64[0] = clib_host_to_net_u64(0xffffffffffffff00ULL);
+    }
+  }
+}
+
+static void
+relax_tuple(fa_5tuple_t *mask, int is_ip6, int relax2){
+	fa_5tuple_t save_mask = *mask;
+
+	int counter_s = 0, counter_d = 0;
+        if (is_ip6) {
+	  int i;
+	  for(i=0; i<2; i++){
+		counter_s += count_bits(mask->ip6_addr[0].as_u64[i]);
+		counter_d += count_bits(mask->ip6_addr[1].as_u64[i]);
+	  }
+        } else {
+		counter_s += count_bits(mask->ip4_addr[0].as_u32);
+		counter_d += count_bits(mask->ip4_addr[1].as_u32);
+        }
+
+/*
+ * is the rule more strongly aligned with source or destination addresses
+ * (usually the two most important fields) and how much slack needs to be
+ * given to allow for other rules. If the source and destination addresses
+ * are close together (within 4 bits for our experiments), we use both of them.
+ * Otherwise, we drop the smaller (less specific) address and its associated
+ * port field from consideration
+ */
+	const int deltaThreshold = 4;
+	/* const int deltaThreshold = 8; if IPV6? */
+	int delta = counter_s - counter_d;
+	if (-delta > deltaThreshold) {
+                if (is_ip6)
+		  mask->ip6_addr[0].as_u64[1] = mask->ip6_addr[0].as_u64[0] = 0;
+                else
+		  mask->ip4_addr[0].as_u32 = 0;
+		mask->l4.port[0] = 0;
+        } else if (delta > deltaThreshold) {
+                if (is_ip6)
+		  mask->ip6_addr[1].as_u64[1] = mask->ip6_addr[1].as_u64[0] = 0;
+                else
+		  mask->ip4_addr[1].as_u32 = 0;
+		mask->l4.port[1] = 0;
+        }
+
+        if (is_ip6) {
+          relax_ip6_addr(&mask->ip6_addr[0], relax2);
+          relax_ip6_addr(&mask->ip6_addr[1], relax2);
+        } else {
+          relax_ip4_addr(&mask->ip4_addr[0], relax2);
+          relax_ip4_addr(&mask->ip4_addr[1], relax2);
+        }
+	mask->pkt.is_nonfirst_fragment = 0;
+	mask->pkt.l4_valid = 0;
+	if(!first_mask_contains_second_mask(is_ip6, mask, &save_mask)){
+		DBG( "TM-relaxing-ERROR");
+                *mask = save_mask;
+	}
+	DBG( "TM-relaxing-end");
+}
+
+
+static u32
+tm_assign_mask_type_index(acl_main_t *am, fa_5tuple_t *mask, int is_ip6, u32 lc_index)
+{
+	u32 mask_type_index = ~0;
+	u32 for_mask_type_index = ~0;
+	ace_mask_type_entry_t *mte;
+	/* look for existing mask comparable with the one in input */
+
+	hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
+	hash_applied_mask_info_t *minfo;
+
+        if (vec_len(*hash_applied_mask_info_vec) > 0) {
+	    for(int order_index = vec_len((*hash_applied_mask_info_vec)) -1; order_index >= 0; order_index--) {
+		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), order_index);
+		for_mask_type_index = minfo->mask_type_index;
+		mte = vec_elt_at_index(am->ace_mask_type_pool, for_mask_type_index);
+		if(first_mask_contains_second_mask(is_ip6, &mte->mask, mask)){
+			mask_type_index = (mte - am->ace_mask_type_pool);
+			break;
+		}
+            }
+	}
+
+	if(~0 == mask_type_index) {
+		/* if no mask is found, then let's use a relaxed version of the original one, in order to be used by new ace_entries */
+		DBG( "TM-assigning mask type index-new one");
+		pool_get_aligned (am->ace_mask_type_pool, mte, CLIB_CACHE_LINE_BYTES);
+		mask_type_index = mte - am->ace_mask_type_pool;
+
+		hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
+
+		int spot = vec_len((*hash_applied_mask_info_vec));
+		vec_validate((*hash_applied_mask_info_vec), spot);
+		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), spot);
+		minfo->mask_type_index = mask_type_index;
+		minfo->num_entries = 0;
+		minfo->max_collisions = 0;
+		minfo->first_rule_index = ~0;
+
+		clib_memcpy(&mte->mask, mask, sizeof(mte->mask));
+		relax_tuple(&mte->mask, is_ip6, 0);
+
+		mte->refcount = 0;
+		/*
+		 * We can use only 16 bits, since in the match there is only u16 field.
+		 * Realistically, once you go to 64K of mask types, it is a huge
+		 * problem anyway, so we might as well stop half way.
+		 */
+		ASSERT(mask_type_index < 32768);
+	}
+	mte = am->ace_mask_type_pool + mask_type_index;
+	mte->refcount++;
+	return mask_type_index;
+}
+
+
 static void
 fill_applied_hash_ace_kv(acl_main_t *am,
                             applied_hash_ace_entry_t **applied_hash_aces,
@@ -241,7 +503,7 @@ add_colliding_rule (acl_main_t * am,
   vec_add1 (head_pae->colliding_rules, cr);
 }
 
-static void
+static u32
 activate_applied_ace_hash_entry(acl_main_t *am,
                             u32 lc_index,
                             applied_hash_ace_entry_t **applied_hash_aces,
@@ -279,12 +541,14 @@ activate_applied_ace_hash_entry(acl_main_t *am,
     /* adjust the pointer to the new tail */
     first_pae->tail_applied_entry_index = new_index;
     add_colliding_rule(am, applied_hash_aces, first_index, new_index);
+    return first_index;
   } else {
     /* It's the very first entry */
     hashtable_add_del(am, &kv, 1);
     ASSERT(new_index != ~0);
     pae->tail_applied_entry_index = new_index;
     add_colliding_rule(am, applied_hash_aces, new_index, new_index);
+    return new_index;
   }
 }
 
@@ -334,7 +598,7 @@ acl_plugin_hash_acl_set_trace_heap(int on)
 }
 
 static void
-assign_mask_type_index_to_pae(acl_main_t *am, applied_hash_ace_entry_t *pae)
+assign_mask_type_index_to_pae(acl_main_t *am, u32 lc_index, int is_ip6, applied_hash_ace_entry_t *pae)
 {
   hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, pae->acl_index);
   hash_ace_info_t *ace_info = vec_elt_at_index(ha->rules, pae->hash_ace_info_index);
@@ -347,7 +611,25 @@ assign_mask_type_index_to_pae(acl_main_t *am, applied_hash_ace_entry_t *pae)
    */
   mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
   mask = &mte->mask;
-  pae->mask_type_index = assign_mask_type_index(am, mask);
+  if (am->use_tuple_merge)
+    pae->mask_type_index = tm_assign_mask_type_index(am, mask, is_ip6, lc_index);
+  else
+    pae->mask_type_index = assign_mask_type_index(am, mask);
+}
+
+static void
+split_partition(acl_main_t *am, u32 first_index,
+                            u32 lc_index, int is_ip6);
+
+
+static void
+check_collision_count_and_maybe_split(acl_main_t *am, u32 lc_index, int is_ip6, u32 first_index)
+{
+  applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);
+  applied_hash_ace_entry_t *first_pae = vec_elt_at_index((*applied_hash_aces), first_index);
+  if (vec_len(first_pae->colliding_rules) > am->tuple_merge_split_threshold) {
+    split_partition(am, first_index, lc_index, is_ip6);
+  }
 }
 
 void
@@ -410,6 +692,7 @@ hash_acl_apply(acl_main_t *am, u32 lc_index, int acl_index, u32 acl_position)
   vec_validate(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
   /* add the rules from the ACL to the hash table for lookup and append to the vector*/
   for(i=0; i < vec_len(ha->rules); i++) {
+    int is_ip6 = ha->rules[i].match.pkt.is_ip6;
     u32 new_index = base_offset + i;
     applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), new_index);
     pae->acl_index = acl_index;
@@ -424,8 +707,10 @@ hash_acl_apply(acl_main_t *am, u32 lc_index, int acl_index, u32 acl_position)
     pae->tail_applied_entry_index = ~0;
     pae->colliding_rules = NULL;
     pae->mask_type_index = ~0;
-    assign_mask_type_index_to_pae(am, pae);
-    activate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, new_index);
+    assign_mask_type_index_to_pae(am, lc_index, is_ip6, pae);
+    u32 first_index = activate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, new_index);
+    if (am->use_tuple_merge)
+      check_collision_count_and_maybe_split(am, lc_index, is_ip6, first_index);
   }
   remake_hash_applied_mask_info_vec(am, applied_hash_aces, lc_index);
 done:
@@ -994,3 +1279,317 @@ acl_plugin_show_tables_bihash (u32 show_bihash_verbose)
   show_hash_acl_hash (vm, am, show_bihash_verbose);
 }
 
+/*
+ * Split of the partition needs to happen when the collision count
+ * goes over a specified threshold.
+ *
+ * This is a signal that we ignored too many bits in
+ * mT and we need to split the table into two tables. We select
+ * all of the colliding rules L and find their maximum common
+ * tuple mL. Normally mL is specific enough to hash L with few
+ * or no collisions. We then create a new table T2 with tuple mL
+ * and transfer all compatible rules from T to T2. If mL is not
+ * specific enough, we find the field with the biggest difference
+ * between the minimum and maximum tuple lengths for all of
+ * the rules in L and set that field to be the average of those two
+ * values. We then transfer all compatible rules as before. This
+ * guarantees that some rules from L will move and that T2 will
+ * have a smaller number of collisions than T did.
+ */
+
+
+static void
+ensure_ip6_min_addr (ip6_address_t * min_addr, ip6_address_t * mask_addr)
+{
+  int update =
+    (clib_net_to_host_u64 (mask_addr->as_u64[0]) <
+     clib_net_to_host_u64 (min_addr->as_u64[0]))
+    ||
+    ((clib_net_to_host_u64 (mask_addr->as_u64[0]) ==
+      clib_net_to_host_u64 (min_addr->as_u64[0]))
+     && (clib_net_to_host_u64 (mask_addr->as_u64[1]) <
+	 clib_net_to_host_u64 (min_addr->as_u64[1])));
+  if (update)
+    {
+      min_addr->as_u64[0] = mask_addr->as_u64[0];
+      min_addr->as_u64[1] = mask_addr->as_u64[1];
+    }
+}
+
+static void
+ensure_ip6_max_addr (ip6_address_t * max_addr, ip6_address_t * mask_addr)
+{
+  int update =
+    (clib_net_to_host_u64 (mask_addr->as_u64[0]) >
+     clib_net_to_host_u64 (max_addr->as_u64[0]))
+    ||
+    ((clib_net_to_host_u64 (mask_addr->as_u64[0]) ==
+      clib_net_to_host_u64 (max_addr->as_u64[0]))
+     && (clib_net_to_host_u64 (mask_addr->as_u64[1]) >
+	 clib_net_to_host_u64 (max_addr->as_u64[1])));
+  if (update)
+    {
+      max_addr->as_u64[0] = mask_addr->as_u64[0];
+      max_addr->as_u64[1] = mask_addr->as_u64[1];
+    }
+}
+
+static void
+ensure_ip4_min_addr (ip4_address_t * min_addr, ip4_address_t * mask_addr)
+{
+  int update =
+    (clib_net_to_host_u32 (mask_addr->as_u32) <
+     clib_net_to_host_u32 (min_addr->as_u32));
+  if (update)
+    min_addr->as_u32 = mask_addr->as_u32;
+}
+
+static void
+ensure_ip4_max_addr (ip4_address_t * max_addr, ip4_address_t * mask_addr)
+{
+  int update =
+    (clib_net_to_host_u32 (mask_addr->as_u32) >
+     clib_net_to_host_u32 (max_addr->as_u32));
+  if (update)
+    max_addr->as_u32 = mask_addr->as_u32;
+}
+
+enum {
+  DIM_SRC_ADDR = 0,
+  DIM_DST_ADDR,
+  DIM_SRC_PORT,
+  DIM_DST_PORT,
+  DIM_PROTO,
+};
+
+
+
+static void
+split_partition(acl_main_t *am, u32 first_index,
+                            u32 lc_index, int is_ip6){
+	DBG( "TM-split_partition - first_entry:%d", first_index);
+        applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);
+	ace_mask_type_entry_t *mte;
+	fa_5tuple_t the_min_tuple, *min_tuple = &the_min_tuple;
+        fa_5tuple_t the_max_tuple, *max_tuple = &the_max_tuple;
+	applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), first_index);
+	hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, pae->acl_index);
+	hash_ace_info_t *ace_info;
+	u32 coll_mask_type_index = pae->mask_type_index;
+        memset(&the_min_tuple, 0, sizeof(the_min_tuple));
+        memset(&the_max_tuple, 0, sizeof(the_max_tuple));
+
+	int i=0;
+	u64 collisions = vec_len(pae->colliding_rules);
+//	while(pae->next_applied_entry_index == ~0){
+	for(i=0; i<collisions; i++){
+
+		DBG( "TM-collision: base_ace:%d (ace_mask:%d, first_collision_mask:%d)",
+				pae->ace_index, pae->mask_type_index, coll_mask_type_index);
+
+		ace_info = vec_elt_at_index(ha->rules, pae->hash_ace_info_index);
+		mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
+		fa_5tuple_t *mask = &mte->mask;
+
+		if(pae->mask_type_index != coll_mask_type_index) continue;
+		/* Computing min_mask and max_mask for colliding rules */
+		if(i==0){
+			clib_memcpy(min_tuple, mask, sizeof(fa_5tuple_t));
+			clib_memcpy(max_tuple, mask, sizeof(fa_5tuple_t));
+		}else{
+			int j;
+			for(j=0; j<2; j++){
+                                if (is_ip6)
+                                  ensure_ip6_min_addr(&min_tuple->ip6_addr[j], &mask->ip6_addr[j]);
+                                else
+                                  ensure_ip4_min_addr(&min_tuple->ip4_addr[j], &mask->ip4_addr[j]);
+
+				if ((mask->l4.port[j] < min_tuple->l4.port[j]))
+					min_tuple->l4.port[j] = mask->l4.port[j];
+			}
+
+			if ((mask->l4.proto < min_tuple->l4.proto))
+				min_tuple->l4.proto = mask->l4.proto;
+
+			if(mask->pkt.as_u64 < min_tuple->pkt.as_u64)
+				min_tuple->pkt.as_u64 = mask->pkt.as_u64;
+
+
+			for(j=0; j<2; j++){
+                                if (is_ip6)
+                                  ensure_ip6_max_addr(&max_tuple->ip6_addr[j], &mask->ip6_addr[j]);
+                                else
+                                  ensure_ip4_max_addr(&max_tuple->ip4_addr[j], &mask->ip4_addr[j]);
+
+				if ((mask->l4.port[j] > max_tuple->l4.port[j]))
+					max_tuple->l4.port[j] = mask->l4.port[j];
+			}
+
+			if ((mask->l4.proto < max_tuple->l4.proto))
+				max_tuple->l4.proto = mask->l4.proto;
+
+			if(mask->pkt.as_u64 > max_tuple->pkt.as_u64)
+				max_tuple->pkt.as_u64 = mask->pkt.as_u64;
+		}
+
+		pae = vec_elt_at_index((*applied_hash_aces), pae->next_applied_entry_index);
+	}
+
+	/* Computing field with max difference between (min/max)_mask */
+	int best_dim=-1, best_delta=0, delta=0;
+
+	/* SRC_addr dimension */
+        if (is_ip6) {
+	  int i;
+	  for(i=0; i<2; i++){
+		delta += count_bits(max_tuple->ip6_addr[0].as_u64[i]) - count_bits(min_tuple->ip6_addr[0].as_u64[i]);
+	  }
+        } else {
+		delta += count_bits(max_tuple->ip4_addr[0].as_u32) - count_bits(min_tuple->ip4_addr[0].as_u32);
+        }
+	if(delta > best_delta){
+		best_delta = delta;
+		best_dim = DIM_SRC_ADDR;
+	}
+
+	/* DST_addr dimension */
+	delta = 0;
+        if (is_ip6) {
+	  int i;
+	  for(i=0; i<2; i++){
+		delta += count_bits(max_tuple->ip6_addr[1].as_u64[i]) - count_bits(min_tuple->ip6_addr[1].as_u64[i]);
+	  }
+        } else {
+		delta += count_bits(max_tuple->ip4_addr[1].as_u32) - count_bits(min_tuple->ip4_addr[1].as_u32);
+        }
+	if(delta > best_delta){
+		best_delta = delta;
+		best_dim = DIM_DST_ADDR;
+	}
+
+	/* SRC_port dimension */
+	delta = count_bits(max_tuple->l4.port[0]) - count_bits(min_tuple->l4.port[0]);
+	if(delta > best_delta){
+		best_delta = delta;
+		best_dim = DIM_SRC_PORT;
+	}
+
+	/* DST_port dimension */
+	delta = count_bits(max_tuple->l4.port[1]) - count_bits(min_tuple->l4.port[1]);
+	if(delta > best_delta){
+		best_delta = delta;
+		best_dim = DIM_DST_PORT;
+	}
+
+	/* Proto dimension */
+	delta = count_bits(max_tuple->l4.proto) - count_bits(min_tuple->l4.proto);
+	if(delta > best_delta){
+		best_delta = delta;
+		best_dim = DIM_PROTO;
+	}
+
+	int shifting = 0; //, ipv4_block = 0;
+	switch(best_dim){
+		case DIM_SRC_ADDR:
+			shifting = (best_delta)/2; // FIXME IPV4-only
+			// ipv4_block = count_bits(max_tuple->ip4_addr[0].as_u32);
+			min_tuple->ip4_addr[0].as_u32 =
+					clib_host_to_net_u32((clib_net_to_host_u32(max_tuple->ip4_addr[0].as_u32) << (shifting))&0xFFFFFFFF);
+
+			break;
+		case DIM_DST_ADDR:
+			shifting = (best_delta)/2;
+/*
+			ipv4_block = count_bits(max_tuple->addr[1].as_u64[1]);
+			if(ipv4_block > shifting)
+				min_tuple->addr[1].as_u64[1] =
+					clib_host_to_net_u64((clib_net_to_host_u64(max_tuple->addr[1].as_u64[1]) << (shifting))&0xFFFFFFFF);
+			else{
+				shifting = shifting - ipv4_block;
+				min_tuple->addr[1].as_u64[1] = 0;
+				min_tuple->addr[1].as_u64[0] =
+					clib_host_to_net_u64((clib_net_to_host_u64(max_tuple->addr[1].as_u64[0]) << (shifting))&0xFFFFFFFF);
+			}
+*/
+			min_tuple->ip4_addr[1].as_u32 =
+					clib_host_to_net_u32((clib_net_to_host_u32(max_tuple->ip4_addr[1].as_u32) << (shifting))&0xFFFFFFFF);
+
+			break;
+		case DIM_SRC_PORT: min_tuple->l4.port[0] = max_tuple->l4.port[0]  << (best_delta)/2;
+			break;
+		case DIM_DST_PORT: min_tuple->l4.port[1] = max_tuple->l4.port[1] << (best_delta)/2;
+			break;
+		case DIM_PROTO: min_tuple->l4.proto = max_tuple->l4.proto << (best_delta)/2;
+			break;
+		default: relax_tuple(min_tuple, is_ip6, 1);
+			break;
+	}
+
+	min_tuple->pkt.is_nonfirst_fragment = 0;
+        u32 new_mask_type_index = assign_mask_type_index(am, min_tuple);
+
+	hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
+
+	hash_applied_mask_info_t *minfo;
+	//search in order pool if mask_type_index is already there
+	int search;
+	for (search=0; search < vec_len((*hash_applied_mask_info_vec)); search++){
+		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), search);
+		if(minfo->mask_type_index == new_mask_type_index)
+			break;
+	}
+
+	vec_validate((*hash_applied_mask_info_vec), search);
+	minfo = vec_elt_at_index((*hash_applied_mask_info_vec), search);
+	minfo->mask_type_index = new_mask_type_index;
+	minfo->num_entries = 0;
+	minfo->max_collisions = 0;
+	minfo->first_rule_index = ~0;
+
+	DBG( "TM-split_partition - mask type index-assigned!! -> %d", new_mask_type_index);
+
+	if(coll_mask_type_index == new_mask_type_index){
+		//vlib_cli_output(vm, "TM-There are collisions over threshold, but i'm not able to split! %d %d", coll_mask_type_index, new_mask_type_index);
+		return;
+	}
+
+
+	/* populate new partition */
+	DBG( "TM-Populate new partition");
+	u32 r_ace_index = first_index;
+
+//	for(i=0; i<collisions; i++){
+	for(r_ace_index=0; r_ace_index < vec_len((*applied_hash_aces)); r_ace_index++) {
+
+		applied_hash_ace_entry_t *pop_pae = vec_elt_at_index((*applied_hash_aces), r_ace_index);
+		DBG( "TM-Population-collision: base_ace:%d (ace_mask:%d, first_collision_mask:%d)",
+				pop_pae->ace_index, pop_pae->mask_type_index, coll_mask_type_index);
+
+		if(pop_pae->mask_type_index != coll_mask_type_index) continue;
+		u32 next_index = pop_pae->next_applied_entry_index;
+
+		ace_info = vec_elt_at_index(ha->rules, pop_pae->hash_ace_info_index);
+		mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
+		//can insert rule?
+		//mte = vec_elt_at_index(am->ace_mask_type_pool, pop_pae->mask_type_index);
+		fa_5tuple_t *pop_mask = &mte->mask;
+
+		if(!first_mask_contains_second_mask(is_ip6, min_tuple, pop_mask)) continue;
+		DBG( "TM-new partition can insert -> applied_ace:%d", r_ace_index);
+
+		//delete and insert in new format
+		deactivate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, r_ace_index);
+
+		/* insert the new entry */
+		pop_pae->mask_type_index = new_mask_type_index;
+
+		activate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, r_ace_index);
+
+		r_ace_index = next_index;
+	}
+
+	DBG( "TM-Populate new partition-END");
+	DBG( "TM-split_partition - END");
+
+}
+