ipsec: introduce fast path ipv4 inbound matching

This patch introduces fast path matching for inbound traffic ipv4.
Fast path uses bihash tables in order to find matching policy. Adding
and removing policies in fast path is much faster than in current
implementation. It is still new feature and further work needs
and can be done in order to improve perfromance.

Type: feature

Signed-off-by: Piotr Bronowski <piotrx.bronowski@intel.com>
Change-Id: Ifbd5bfecc21b76ddf8363f5dc089d77595196675
diff --git a/src/vnet/ipsec/ipsec_spd_fp_lookup.h b/src/vnet/ipsec/ipsec_spd_fp_lookup.h
index 3aea86f..e4ef194 100644
--- a/src/vnet/ipsec/ipsec_spd_fp_lookup.h
+++ b/src/vnet/ipsec/ipsec_spd_fp_lookup.h
@@ -20,18 +20,6 @@
 
 #include <vnet/ipsec/ipsec.h>
 
-/**
- * @brief function handler to perform lookup in fastpath SPD
- * for inbound traffic burst of n packets
- **/
-
-inline u32
-ipsec_fp_in_policy_match_n (void *spd_fp, u8 is_ipv6,
-			    ipsec_fp_5tuple_t *tuples,
-			    ipsec_policy_t **policies, u32 *policy_ids, u32 n)
-{
-  return 0;
-}
 
 static_always_inline int
 single_rule_match_5tuple (ipsec_policy_t *policy, ipsec_fp_5tuple_t *match)
@@ -106,6 +94,164 @@
   return (1);
 }
 
+static_always_inline int
+single_rule_in_match_5tuple (ipsec_policy_t *policy, ipsec_fp_5tuple_t *match)
+{
+
+  u32 sa = clib_net_to_host_u32 (match->laddr.as_u32);
+  u32 da = clib_net_to_host_u32 (match->raddr.as_u32);
+
+  if (policy->policy == IPSEC_POLICY_ACTION_PROTECT)
+    {
+      ipsec_sa_t *s = ipsec_sa_get (policy->sa_index);
+
+      if (match->spi != s->spi)
+	return (0);
+
+      if (ipsec_sa_is_set_IS_TUNNEL (s))
+	{
+	  if (da != clib_net_to_host_u32 (s->tunnel.t_dst.ip.ip4.as_u32))
+	    return (0);
+
+	  if (sa != clib_net_to_host_u32 (s->tunnel.t_src.ip.ip4.as_u32))
+	    return (0);
+	}
+    }
+  else
+    {
+      if (da < clib_net_to_host_u32 (policy->raddr.start.ip4.as_u32))
+	return (0);
+
+      if (da > clib_net_to_host_u32 (policy->raddr.stop.ip4.as_u32))
+	return (0);
+
+      if (sa < clib_net_to_host_u32 (policy->laddr.start.ip4.as_u32))
+	return (0);
+
+      if (sa > clib_net_to_host_u32 (policy->laddr.stop.ip4.as_u32))
+	return (0);
+    }
+  return (1);
+}
+
+static_always_inline u32
+ipsec_fp_in_ip6_policy_match_n (void *spd_fp, ipsec_fp_5tuple_t *tuples,
+				ipsec_policy_t **policies, u32 n)
+{
+  return 0;
+}
+
+static_always_inline u32
+ipsec_fp_in_ip4_policy_match_n (void *spd_fp, ipsec_fp_5tuple_t *tuples,
+				ipsec_policy_t **policies, u32 n)
+
+{
+  u32 last_priority[n];
+  u32 i = 0;
+  u32 counter = 0;
+  ipsec_fp_mask_type_entry_t *mte;
+  ipsec_fp_mask_id_t *mti;
+  ipsec_fp_5tuple_t *match = tuples;
+  ipsec_policy_t *policy;
+  u32 n_left = n;
+  clib_bihash_kv_16_8_t kv;
+  /* result of the lookup */
+  clib_bihash_kv_16_8_t result;
+  ipsec_fp_lookup_value_t *result_val =
+    (ipsec_fp_lookup_value_t *) &result.value;
+  u64 *pkey, *pmatch, *pmask;
+  ipsec_main_t *im = &ipsec_main;
+  ipsec_spd_fp_t *pspd_fp = (ipsec_spd_fp_t *) spd_fp;
+  ipsec_fp_mask_id_t *mask_type_ids = pspd_fp->fp_mask_ids[match->action];
+  clib_bihash_16_8_t *bihash_table = pool_elt_at_index (
+    im->fp_ip4_lookup_hashes_pool, pspd_fp->ip4_in_lookup_hash_idx);
+
+  /* clear the list of matched policies pointers */
+  clib_memset (policies, 0, n * sizeof (*policies));
+  clib_memset (last_priority, 0, n * sizeof (u32));
+  n_left = n;
+  while (n_left)
+    {
+      vec_foreach (mti, mask_type_ids)
+	{
+	  mte = im->fp_mask_types + mti->mask_type_idx;
+	  if (mte->mask.action == 0)
+	    continue;
+	  pmatch = (u64 *) match->kv_16_8.key;
+	  pmask = (u64 *) mte->mask.kv_16_8.key;
+	  pkey = (u64 *) kv.key;
+
+	  *pkey++ = *pmatch++ & *pmask++;
+	  *pkey = *pmatch & *pmask;
+
+	  int res =
+	    clib_bihash_search_inline_2_16_8 (bihash_table, &kv, &result);
+	  /* lookup the hash by each packet in the burst for this mask. */
+
+	  if (res == 0)
+	    {
+	      /* There is a hit in the hash table. */
+	      /* Find the policy with highest priority. */
+	      /* Store the lookup results in a dedicated array. */
+
+	      if (vec_len (result_val->fp_policies_ids) > 1)
+		{
+		  u32 *policy_id;
+		  vec_foreach (policy_id, result_val->fp_policies_ids)
+		    {
+		      policy = im->policies + *policy_id;
+
+		      if ((last_priority[i] < policy->priority) &&
+			  (single_rule_in_match_5tuple (policy, match)))
+			{
+			  last_priority[i] = policy->priority;
+			  if (policies[i] == 0)
+			    counter++;
+			  policies[i] = policy;
+			}
+		    }
+		}
+	      else
+		{
+		  u32 *policy_id;
+		  ASSERT (vec_len (result_val->fp_policies_ids) == 1);
+		  policy_id = result_val->fp_policies_ids;
+		  policy = im->policies + *policy_id;
+		  if ((last_priority[i] < policy->priority) &&
+		      (single_rule_in_match_5tuple (policy, match)))
+		    {
+		      last_priority[i] = policy->priority;
+		      if (policies[i] == 0)
+			counter++;
+		      policies[i] = policy;
+		    }
+		}
+	    }
+	}
+
+      i++;
+      n_left--;
+      match++;
+    }
+  return counter;
+}
+
+/**
+ * @brief function handler to perform lookup in fastpath SPD
+ * for inbound traffic burst of n packets
+ **/
+
+static_always_inline u32
+ipsec_fp_in_policy_match_n (void *spd_fp, u8 is_ipv6,
+			    ipsec_fp_5tuple_t *tuples,
+			    ipsec_policy_t **policies, u32 n)
+{
+  if (is_ipv6)
+    return ipsec_fp_in_ip6_policy_match_n (spd_fp, tuples, policies, n);
+  else
+    return ipsec_fp_in_ip4_policy_match_n (spd_fp, tuples, policies, n);
+}
+
 static_always_inline u32
 ipsec_fp_ip6_out_policy_match_n (void *spd_fp, ipsec_fp_5tuple_t *tuples,
 				 ipsec_policy_t **policies, u32 *ids, u32 n)
@@ -115,7 +261,7 @@
   u32 i = 0;
   u32 counter = 0;
   ipsec_fp_mask_type_entry_t *mte;
-  u32 *mti;
+  ipsec_fp_mask_id_t *mti;
   ipsec_fp_5tuple_t *match = tuples;
   ipsec_policy_t *policy;
 
@@ -128,7 +274,10 @@
   u64 *pkey, *pmatch, *pmask;
   ipsec_main_t *im = &ipsec_main;
   ipsec_spd_fp_t *pspd_fp = (ipsec_spd_fp_t *) spd_fp;
-  u32 *mask_type_ids = pspd_fp->fp_mask_types[IPSEC_SPD_POLICY_IP6_OUTBOUND];
+  ipsec_fp_mask_id_t *mask_type_ids =
+    pspd_fp->fp_mask_ids[IPSEC_SPD_POLICY_IP6_OUTBOUND];
+  clib_bihash_40_8_t *bihash_table = pool_elt_at_index (
+    im->fp_ip6_lookup_hashes_pool, pspd_fp->ip6_out_lookup_hash_idx);
 
   /*clear the list of matched policies pointers */
   clib_memset (policies, 0, n * sizeof (*policies));
@@ -138,7 +287,7 @@
     {
       vec_foreach (mti, mask_type_ids)
 	{
-	  mte = im->fp_mask_types + *mti;
+	  mte = im->fp_mask_types + mti->mask_type_idx;
 
 	  pmatch = (u64 *) match->kv_40_8.key;
 	  pmask = (u64 *) mte->mask.kv_40_8.key;
@@ -150,8 +299,8 @@
 	  *pkey++ = *pmatch++ & *pmask++;
 	  *pkey = *pmatch & *pmask;
 
-	  int res = clib_bihash_search_inline_2_40_8 (
-	    &pspd_fp->fp_ip6_lookup_hash, &kv, &result);
+	  int res =
+	    clib_bihash_search_inline_2_40_8 (bihash_table, &kv, &result);
 	  /* lookup the hash by each packet in the burst for this mask. */
 
 	  if (res == 0)
@@ -216,7 +365,7 @@
   u32 i = 0;
   u32 counter = 0;
   ipsec_fp_mask_type_entry_t *mte;
-  u32 *mti;
+  ipsec_fp_mask_id_t *mti;
   ipsec_fp_5tuple_t *match = tuples;
   ipsec_policy_t *policy;
 
@@ -229,7 +378,10 @@
   u64 *pkey, *pmatch, *pmask;
   ipsec_main_t *im = &ipsec_main;
   ipsec_spd_fp_t *pspd_fp = (ipsec_spd_fp_t *) spd_fp;
-  u32 *mask_type_ids = pspd_fp->fp_mask_types[IPSEC_SPD_POLICY_IP4_OUTBOUND];
+  ipsec_fp_mask_id_t *mask_type_ids =
+    pspd_fp->fp_mask_ids[IPSEC_SPD_POLICY_IP4_OUTBOUND];
+  clib_bihash_16_8_t *bihash_table = pool_elt_at_index (
+    im->fp_ip4_lookup_hashes_pool, pspd_fp->ip4_out_lookup_hash_idx);
 
   /* clear the list of matched policies pointers */
   clib_memset (policies, 0, n * sizeof (*policies));
@@ -239,7 +391,9 @@
     {
       vec_foreach (mti, mask_type_ids)
 	{
-	  mte = im->fp_mask_types + *mti;
+	  mte = im->fp_mask_types + mti->mask_type_idx;
+	  if (mte->mask.action != 0)
+	    continue;
 
 	  pmatch = (u64 *) match->kv_16_8.key;
 	  pmask = (u64 *) mte->mask.kv_16_8.key;
@@ -248,8 +402,8 @@
 	  *pkey++ = *pmatch++ & *pmask++;
 	  *pkey = *pmatch & *pmask;
 
-	  int res = clib_bihash_search_inline_2_16_8 (
-	    &pspd_fp->fp_ip4_lookup_hash, &kv, &result);
+	  int res =
+	    clib_bihash_search_inline_2_16_8 (bihash_table, &kv, &result);
 	  /* lookup the hash by each packet in the burst for this mask. */
 
 	  if (res == 0)