acl-plugin: refactor to introduce multiarch dataplane functions

This commit splits the functions from fa_node.c
into the pure dataplane node functions (which are multiarch-compiled),
session management node functions (which are compiled only once),
and session find/add/delete functions which are split out into the inlines.

As part of the refactoring:

- get rid of BV() macros in the affected chunk of code,
  rather use the explicit bihash function names.

- add the magic trailer to the new files to
  ensure make checkstyle watches them.

- move the bihash_template.c include for 40_8 bihash into acl.c

Change-Id: I4d781e9ec4307ea84e92af93c09470ea2bd0c375
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

5 files changed, 1997 insertions, 1614 deletions

diff --git a/src/plugins/acl/acl.c b/src/plugins/acl/acl.c
index f7156847241..65785cc0f5a 100644
--- a/src/plugins/acl/acl.c
+++ b/src/plugins/acl/acl.c
@@ -59,6 +59,13 @@ acl_main_t *p_acl_main = &acl_main;
 #define REPLY_MSG_ID_BASE am->msg_id_base
 #include <vlibapi/api_helper_macros.h>
 
+/*
+ * The code for the bihash, used by the session management.
+ */
+#include <vppinfra/bihash_40_8.h>
+#include <vppinfra/bihash_template.h>
+#include <vppinfra/bihash_template.c>
+
 /* List of message types that this plugin understands */
 
 #define foreach_acl_plugin_api_msg		\
diff --git a/src/plugins/acl/dataplane_node.c b/src/plugins/acl/dataplane_node.c
new file mode 100644
index 00000000000..98e966189d8
--- /dev/null
+++ b/src/plugins/acl/dataplane_node.c
@@ -0,0 +1,758 @@
+/*
+ * Copyright (c) 2016-2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stddef.h>
+#include <netinet/in.h>
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+
+
+#include <acl/acl.h>
+#include <vnet/ip/icmp46_packet.h>
+
+#include <plugins/acl/fa_node.h>
+#include <plugins/acl/acl.h>
+#include <plugins/acl/lookup_context.h>
+#include <plugins/acl/public_inlines.h>
+#include <plugins/acl/session_inlines.h>
+
+#include <vppinfra/bihash_40_8.h>
+#include <vppinfra/bihash_template.h>
+
+typedef struct
+{
+  u32 next_index;
+  u32 sw_if_index;
+  u32 lc_index;
+  u32 match_acl_in_index;
+  u32 match_rule_index;
+  u64 packet_info[6];
+  u32 trace_bitmap;
+  u8 action;
+} acl_fa_trace_t;
+
+/* *INDENT-OFF* */
+#define foreach_acl_fa_error \
+_(ACL_DROP, "ACL deny packets")  \
+_(ACL_PERMIT, "ACL permit packets")  \
+_(ACL_NEW_SESSION, "new sessions added") \
+_(ACL_EXIST_SESSION, "existing session packets") \
+_(ACL_CHECK, "checked packets") \
+_(ACL_RESTART_SESSION_TIMER, "restart session timer") \
+_(ACL_TOO_MANY_SESSIONS, "too many sessions to add new") \
+/* end  of errors */
+
+typedef enum
+{
+#define _(sym,str) ACL_FA_ERROR_##sym,
+  foreach_acl_fa_error
+#undef _
+    ACL_FA_N_ERROR,
+} acl_fa_error_t;
+
+/* *INDENT-ON* */
+
+
+always_inline uword
+acl_fa_node_fn (vlib_main_t * vm,
+		vlib_node_runtime_t * node, vlib_frame_t * frame, int is_ip6,
+		int is_input, int is_l2_path, u32 * l2_feat_next_node_index,
+		vlib_node_registration_t * acl_fa_node)
+{
+  u32 n_left_from, *from, *to_next;
+  acl_fa_next_t next_index;
+  u32 pkts_acl_checked = 0;
+  u32 pkts_new_session = 0;
+  u32 pkts_exist_session = 0;
+  u32 pkts_acl_permit = 0;
+  u32 pkts_restart_session_timer = 0;
+  u32 trace_bitmap = 0;
+  acl_main_t *am = &acl_main;
+  fa_5tuple_t fa_5tuple, kv_sess;
+  clib_bihash_kv_40_8_t value_sess;
+  vlib_node_runtime_t *error_node;
+  u64 now = clib_cpu_time_now ();
+  uword thread_index = os_get_thread_index ();
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  error_node = vlib_node_get_runtime (vm, acl_fa_node->index);
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  u32 next0 = 0;
+	  u8 action = 0;
+	  u32 sw_if_index0;
+	  u32 lc_index0;
+	  int acl_check_needed = 1;
+	  u32 match_acl_in_index = ~0;
+	  u32 match_acl_pos = ~0;
+	  u32 match_rule_index = ~0;
+	  u8 error0 = 0;
+	  u32 valid_new_sess;
+
+	  /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  if (is_input)
+	    sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  else
+	    sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+
+	  if (is_input)
+	    lc_index0 = am->input_lc_index_by_sw_if_index[sw_if_index0];
+	  else
+	    lc_index0 = am->output_lc_index_by_sw_if_index[sw_if_index0];
+
+	  u32 **p_epoch_vec =
+	    is_input ? &am->input_policy_epoch_by_sw_if_index :
+	    &am->output_policy_epoch_by_sw_if_index;
+	  u16 current_policy_epoch =
+	    sw_if_index0 < vec_len (*p_epoch_vec) ? vec_elt (*p_epoch_vec,
+							     sw_if_index0)
+	    : (is_input * FA_POLICY_EPOCH_IS_INPUT);
+	  /*
+	   * Extract the L3/L4 matching info into a 5-tuple structure,
+	   * then create a session key whose layout is independent on forward or reverse
+	   * direction of the packet.
+	   */
+
+	  acl_plugin_fill_5tuple_inline (lc_index0, b0, is_ip6, is_input,
+					 is_l2_path,
+					 (fa_5tuple_opaque_t *) & fa_5tuple);
+	  fa_5tuple.l4.lsb_of_sw_if_index = sw_if_index0 & 0xffff;
+	  valid_new_sess =
+	    acl_make_5tuple_session_key (am, is_input, is_ip6, sw_if_index0,
+					 &fa_5tuple, &kv_sess);
+	  // XXDEL fa_5tuple.pkt.is_input = is_input;
+	  fa_5tuple.pkt.mask_type_index_lsb = ~0;
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning
+	    ("ACL_FA_NODE_DBG: session 5-tuple %016llx %016llx %016llx %016llx %016llx %016llx",
+	     kv_sess.kv.key[0], kv_sess.kv.key[1], kv_sess.kv.key[2],
+	     kv_sess.kv.key[3], kv_sess.kv.key[4], kv_sess.kv.value);
+	  clib_warning
+	    ("ACL_FA_NODE_DBG: packet 5-tuple %016llx %016llx %016llx %016llx %016llx %016llx",
+	     fa_5tuple.kv.key[0], fa_5tuple.kv.key[1], fa_5tuple.kv.key[2],
+	     fa_5tuple.kv.key[3], fa_5tuple.kv.key[4], fa_5tuple.kv.value);
+#endif
+
+	  /* Try to match an existing session first */
+
+	  if (acl_fa_ifc_has_sessions (am, sw_if_index0))
+	    {
+	      if (acl_fa_find_session
+		  (am, sw_if_index0, &kv_sess, &value_sess))
+		{
+		  trace_bitmap |= 0x80000000;
+		  error0 = ACL_FA_ERROR_ACL_EXIST_SESSION;
+		  fa_full_session_id_t f_sess_id;
+
+		  f_sess_id.as_u64 = value_sess.value;
+		  ASSERT (f_sess_id.thread_index < vec_len (vlib_mains));
+
+		  fa_session_t *sess =
+		    get_session_ptr (am, f_sess_id.thread_index,
+				     f_sess_id.session_index);
+		  int old_timeout_type =
+		    fa_session_get_timeout_type (am, sess);
+		  action =
+		    acl_fa_track_session (am, is_input, sw_if_index0, now,
+					  sess, &fa_5tuple);
+		  /* expose the session id to the tracer */
+		  match_rule_index = f_sess_id.session_index;
+		  int new_timeout_type =
+		    fa_session_get_timeout_type (am, sess);
+		  acl_check_needed = 0;
+		  pkts_exist_session += 1;
+		  /* Tracking might have changed the session timeout type, e.g. from transient to established */
+		  if (PREDICT_FALSE (old_timeout_type != new_timeout_type))
+		    {
+		      acl_fa_restart_timer_for_session (am, now, f_sess_id);
+		      pkts_restart_session_timer++;
+		      trace_bitmap |=
+			0x00010000 + ((0xff & old_timeout_type) << 8) +
+			(0xff & new_timeout_type);
+		    }
+		  /*
+		   * I estimate the likelihood to be very low - the VPP needs
+		   * to have >64K interfaces to start with and then on
+		   * exactly 64K indices apart needs to be exactly the same
+		   * 5-tuple... Anyway, since this probability is nonzero -
+		   * print an error and drop the unlucky packet.
+		   * If this shows up in real world, we would need to bump
+		   * the hash key length.
+		   */
+		  if (PREDICT_FALSE (sess->sw_if_index != sw_if_index0))
+		    {
+		      clib_warning
+			("BUG: session LSB16(sw_if_index) and 5-tuple collision!");
+		      acl_check_needed = 0;
+		      action = 0;
+		    }
+		  if (PREDICT_FALSE (am->reclassify_sessions))
+		    {
+		      /* if the MSB of policy epoch matches but not the LSB means it is a stale session */
+		      if ((0 ==
+			   ((current_policy_epoch ^
+			     f_sess_id.intf_policy_epoch) &
+			    FA_POLICY_EPOCH_IS_INPUT))
+			  && (current_policy_epoch !=
+			      f_sess_id.intf_policy_epoch))
+			{
+			  /* delete session and increment the counter */
+			  vec_validate
+			    (pw->fa_session_epoch_change_by_sw_if_index,
+			     sw_if_index0);
+			  vec_elt (pw->fa_session_epoch_change_by_sw_if_index,
+				   sw_if_index0)++;
+			  if (acl_fa_conn_list_delete_session (am, f_sess_id))
+			    {
+			      /* delete the session only if we were able to unlink it */
+			      acl_fa_delete_session (am, sw_if_index0,
+						     f_sess_id);
+			    }
+			  acl_check_needed = 1;
+			  trace_bitmap |= 0x40000000;
+			}
+		    }
+		}
+	    }
+
+	  if (acl_check_needed)
+	    {
+	      action = 0;	/* deny by default */
+	      acl_plugin_match_5tuple_inline (lc_index0,
+					      (fa_5tuple_opaque_t *) &
+					      fa_5tuple, is_ip6, &action,
+					      &match_acl_pos,
+					      &match_acl_in_index,
+					      &match_rule_index,
+					      &trace_bitmap);
+	      error0 = action;
+	      if (1 == action)
+		pkts_acl_permit += 1;
+	      if (2 == action)
+		{
+		  if (!acl_fa_can_add_session (am, is_input, sw_if_index0))
+		    acl_fa_try_recycle_session (am, is_input, thread_index,
+						sw_if_index0);
+
+		  if (acl_fa_can_add_session (am, is_input, sw_if_index0))
+		    {
+		      if (PREDICT_TRUE (valid_new_sess))
+			{
+			  fa_session_t *sess =
+			    acl_fa_add_session (am, is_input,
+						sw_if_index0,
+						now, &kv_sess,
+						current_policy_epoch);
+			  acl_fa_track_session (am, is_input, sw_if_index0,
+						now, sess, &fa_5tuple);
+			  pkts_new_session += 1;
+			}
+		      else
+			{
+			  /*
+			   *  ICMP packets with non-icmp_valid_new type will be
+			   *  forwared without being dropped.
+			   */
+			  action = 1;
+			  pkts_acl_permit += 1;
+			}
+		    }
+		  else
+		    {
+		      action = 0;
+		      error0 = ACL_FA_ERROR_ACL_TOO_MANY_SESSIONS;
+		    }
+		}
+	    }
+
+
+
+	  if (action > 0)
+	    {
+	      if (is_l2_path)
+		next0 = vnet_l2_feature_next (b0, l2_feat_next_node_index, 0);
+	      else
+		vnet_feature_next (sw_if_index0, &next0, b0);
+	    }
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning
+	    ("ACL_FA_NODE_DBG: sw_if_index %d lc_index %d action %d acl_index %d rule_index %d",
+	     sw_if_index0, lc_index0, action, match_acl_in_index,
+	     match_rule_index);
+#endif
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      acl_fa_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = sw_if_index0;
+	      t->lc_index = lc_index0;
+	      t->next_index = next0;
+	      t->match_acl_in_index = match_acl_in_index;
+	      t->match_rule_index = match_rule_index;
+	      t->packet_info[0] = fa_5tuple.kv.key[0];
+	      t->packet_info[1] = fa_5tuple.kv.key[1];
+	      t->packet_info[2] = fa_5tuple.kv.key[2];
+	      t->packet_info[3] = fa_5tuple.kv.key[3];
+	      t->packet_info[4] = fa_5tuple.kv.key[4];
+	      t->packet_info[5] = fa_5tuple.kv.value;
+	      t->action = action;
+	      t->trace_bitmap = trace_bitmap;
+	    }
+
+	  next0 = next0 < node->n_next_nodes ? next0 : 0;
+	  if (0 == next0)
+	    b0->error = error_node->errors[error0];
+
+	  pkts_acl_checked += 1;
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next, bi0,
+					   next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, acl_fa_node->index,
+			       ACL_FA_ERROR_ACL_CHECK, pkts_acl_checked);
+  vlib_node_increment_counter (vm, acl_fa_node->index,
+			       ACL_FA_ERROR_ACL_PERMIT, pkts_acl_permit);
+  vlib_node_increment_counter (vm, acl_fa_node->index,
+			       ACL_FA_ERROR_ACL_NEW_SESSION,
+			       pkts_new_session);
+  vlib_node_increment_counter (vm, acl_fa_node->index,
+			       ACL_FA_ERROR_ACL_EXIST_SESSION,
+			       pkts_exist_session);
+  vlib_node_increment_counter (vm, acl_fa_node->index,
+			       ACL_FA_ERROR_ACL_RESTART_SESSION_TIMER,
+			       pkts_restart_session_timer);
+  return frame->n_vectors;
+}
+
+vlib_node_function_t __clib_weak acl_in_ip4_l2_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_in_ip4_l2_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_out_ip4_l2_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_out_ip4_l2_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_in_ip6_l2_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_in_ip6_l2_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_out_ip6_l2_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_out_ip6_l2_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_in_ip4_fa_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_in_ip4_fa_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_out_ip4_fa_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_out_ip4_fa_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_in_ip6_fa_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_in_ip6_fa_node_fn_avx2;
+
+vlib_node_function_t __clib_weak acl_out_ip6_fa_node_fn_avx512;
+vlib_node_function_t __clib_weak acl_out_ip6_fa_node_fn_avx2;
+
+
+vlib_node_registration_t acl_in_l2_ip6_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_in_ip6_l2_node_fn) (vlib_main_t * vm,
+					   vlib_node_runtime_t * node,
+					   vlib_frame_t * frame)
+{
+  acl_main_t *am = &acl_main;
+  return acl_fa_node_fn (vm, node, frame, 1, 1, 1,
+			 am->fa_acl_in_ip6_l2_node_feat_next_node_index,
+			 &acl_in_l2_ip6_node);
+}
+
+vlib_node_registration_t acl_in_l2_ip4_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_in_ip4_l2_node_fn) (vlib_main_t * vm,
+					   vlib_node_runtime_t * node,
+					   vlib_frame_t * frame)
+{
+  acl_main_t *am = &acl_main;
+  return acl_fa_node_fn (vm, node, frame, 0, 1, 1,
+			 am->fa_acl_in_ip4_l2_node_feat_next_node_index,
+			 &acl_in_l2_ip4_node);
+}
+
+vlib_node_registration_t acl_out_l2_ip6_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_out_ip6_l2_node_fn) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  acl_main_t *am = &acl_main;
+  return acl_fa_node_fn (vm, node, frame, 1, 0, 1,
+			 am->fa_acl_out_ip6_l2_node_feat_next_node_index,
+			 &acl_out_l2_ip6_node);
+}
+
+vlib_node_registration_t acl_out_l2_ip4_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_out_ip4_l2_node_fn) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  acl_main_t *am = &acl_main;
+  return acl_fa_node_fn (vm, node, frame, 0, 0, 1,
+			 am->fa_acl_out_ip4_l2_node_feat_next_node_index,
+			 &acl_out_l2_ip4_node);
+}
+
+/**** L3 processing path nodes ****/
+
+vlib_node_registration_t acl_in_fa_ip6_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_in_ip6_fa_node_fn) (vlib_main_t * vm,
+					   vlib_node_runtime_t * node,
+					   vlib_frame_t * frame)
+{
+  return acl_fa_node_fn (vm, node, frame, 1, 1, 0, 0, &acl_in_fa_ip6_node);
+}
+
+vlib_node_registration_t acl_in_fa_ip4_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_in_ip4_fa_node_fn) (vlib_main_t * vm,
+					   vlib_node_runtime_t * node,
+					   vlib_frame_t * frame)
+{
+  return acl_fa_node_fn (vm, node, frame, 0, 1, 0, 0, &acl_in_fa_ip4_node);
+}
+
+vlib_node_registration_t acl_out_fa_ip6_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_out_ip6_fa_node_fn) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  return acl_fa_node_fn (vm, node, frame, 1, 0, 0, 0, &acl_out_fa_ip6_node);
+}
+
+vlib_node_registration_t acl_out_fa_ip4_node;
+uword CLIB_CPU_OPTIMIZED
+CLIB_MULTIARCH_FN (acl_out_ip4_fa_node_fn) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  return acl_fa_node_fn (vm, node, frame, 0, 0, 0, 0, &acl_out_fa_ip4_node);
+}
+
+
+
+#if __x86_64__
+static void __clib_constructor
+acl_plugin_multiarch_select (void)
+{
+  if (acl_in_ip4_l2_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_in_l2_ip4_node.function = acl_in_ip4_l2_node_fn_avx512;
+  else if (acl_in_ip4_l2_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_in_l2_ip4_node.function = acl_in_ip4_l2_node_fn_avx2;
+
+  if (acl_out_ip4_l2_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_out_l2_ip4_node.function = acl_out_ip4_l2_node_fn_avx512;
+  else if (acl_out_ip4_l2_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_out_l2_ip4_node.function = acl_out_ip4_l2_node_fn_avx2;
+
+  if (acl_in_ip6_l2_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_in_l2_ip6_node.function = acl_in_ip6_l2_node_fn_avx512;
+  else if (acl_in_ip6_l2_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_in_l2_ip6_node.function = acl_in_ip6_l2_node_fn_avx2;
+
+  if (acl_out_ip6_l2_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_out_l2_ip6_node.function = acl_out_ip6_l2_node_fn_avx512;
+  else if (acl_out_ip6_l2_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_out_l2_ip6_node.function = acl_out_ip6_l2_node_fn_avx2;
+
+  if (acl_in_ip4_fa_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_in_fa_ip4_node.function = acl_in_ip4_fa_node_fn_avx512;
+  else if (acl_in_ip4_fa_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_in_fa_ip4_node.function = acl_in_ip4_fa_node_fn_avx2;
+
+  if (acl_out_ip4_fa_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_out_fa_ip4_node.function = acl_out_ip4_fa_node_fn_avx512;
+  else if (acl_out_ip4_fa_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_out_fa_ip4_node.function = acl_out_ip4_fa_node_fn_avx2;
+
+  if (acl_in_ip6_fa_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_in_fa_ip6_node.function = acl_in_ip6_fa_node_fn_avx512;
+  else if (acl_in_ip6_fa_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_in_fa_ip6_node.function = acl_in_ip6_fa_node_fn_avx2;
+
+  if (acl_out_ip6_fa_node_fn_avx512 && clib_cpu_supports_avx512f ())
+    acl_out_fa_ip6_node.function = acl_out_ip6_fa_node_fn_avx512;
+  else if (acl_out_ip6_fa_node_fn_avx2 && clib_cpu_supports_avx2 ())
+    acl_out_fa_ip6_node.function = acl_out_ip6_fa_node_fn_avx2;
+
+}
+#endif
+
+
+
+#ifndef CLIB_MULTIARCH_VARIANT
+static u8 *
+format_fa_5tuple (u8 * s, va_list * args)
+{
+  fa_5tuple_t *p5t = va_arg (*args, fa_5tuple_t *);
+
+  return format (s, "lc_index %d (lsb16 of sw_if_index %d) l3 %s%s %U -> %U"
+		 " l4 proto %d l4_valid %d port %d -> %d tcp flags (%s) %02x rsvd %x",
+		 p5t->pkt.lc_index, p5t->l4.lsb_of_sw_if_index,
+		 p5t->pkt.is_ip6 ? "ip6" : "ip4",
+		 p5t->pkt.is_nonfirst_fragment ? " non-initial fragment" : "",
+		 format_ip46_address, &p5t->addr[0],
+		 p5t->pkt.is_ip6 ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		 format_ip46_address, &p5t->addr[1],
+		 p5t->pkt.is_ip6 ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		 p5t->l4.proto, p5t->pkt.l4_valid, p5t->l4.port[0],
+		 p5t->l4.port[1],
+		 p5t->pkt.tcp_flags_valid ? "valid" : "invalid",
+		 p5t->pkt.tcp_flags, p5t->pkt.flags_reserved);
+}
+
+u8 *
+format_acl_plugin_5tuple (u8 * s, va_list * args)
+{
+  return format_fa_5tuple (s, args);
+}
+
+/* packet trace format function */
+u8 *
+format_acl_plugin_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  acl_fa_trace_t *t = va_arg (*args, acl_fa_trace_t *);
+
+  s =
+    format (s,
+	    "acl-plugin: lc_index: %d, sw_if_index %d, next index %d, action: %d, match: acl %d rule %d trace_bits %08x\n"
+	    "  pkt info %016llx %016llx %016llx %016llx %016llx %016llx",
+	    t->lc_index, t->sw_if_index, t->next_index, t->action,
+	    t->match_acl_in_index, t->match_rule_index, t->trace_bitmap,
+	    t->packet_info[0], t->packet_info[1], t->packet_info[2],
+	    t->packet_info[3], t->packet_info[4], t->packet_info[5]);
+
+  /* Now also print out the packet_info in a form usable by humans */
+  s = format (s, "\n   %U", format_fa_5tuple, t->packet_info);
+  return s;
+}
+
+
+/* *INDENT-OFF* */
+
+static char *acl_fa_error_strings[] = {
+#define _(sym,string) string,
+  foreach_acl_fa_error
+#undef _
+};
+
+VLIB_REGISTER_NODE (acl_in_l2_ip6_node) =
+{
+  .function = acl_in_ip6_l2_node_fn,
+  .name = "acl-plugin-in-ip6-l2",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VLIB_REGISTER_NODE (acl_in_l2_ip4_node) =
+{
+  .function = acl_in_ip4_l2_node_fn,
+  .name = "acl-plugin-in-ip4-l2",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VLIB_REGISTER_NODE (acl_out_l2_ip6_node) =
+{
+  .function = acl_out_ip6_l2_node_fn,
+  .name = "acl-plugin-out-ip6-l2",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VLIB_REGISTER_NODE (acl_out_l2_ip4_node) =
+{
+  .function = acl_out_ip4_l2_node_fn,
+  .name = "acl-plugin-out-ip4-l2",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+
+VLIB_REGISTER_NODE (acl_in_fa_ip6_node) =
+{
+  .function = acl_in_ip6_fa_node_fn,
+  .name = "acl-plugin-in-ip6-fa",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VNET_FEATURE_INIT (acl_in_ip6_fa_feature, static) =
+{
+  .arc_name = "ip6-unicast",
+  .node_name = "acl-plugin-in-ip6-fa",
+  .runs_before = VNET_FEATURES ("ip6-flow-classify"),
+};
+
+VLIB_REGISTER_NODE (acl_in_fa_ip4_node) =
+{
+  .function = acl_in_ip4_fa_node_fn,
+  .name = "acl-plugin-in-ip4-fa",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VNET_FEATURE_INIT (acl_in_ip4_fa_feature, static) =
+{
+  .arc_name = "ip4-unicast",
+  .node_name = "acl-plugin-in-ip4-fa",
+  .runs_before = VNET_FEATURES ("ip4-flow-classify"),
+};
+
+
+VLIB_REGISTER_NODE (acl_out_fa_ip6_node) =
+{
+  .function = acl_out_ip6_fa_node_fn,
+  .name = "acl-plugin-out-ip6-fa",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VNET_FEATURE_INIT (acl_out_ip6_fa_feature, static) =
+{
+  .arc_name = "ip6-output",
+  .node_name = "acl-plugin-out-ip6-fa",
+  .runs_before = VNET_FEATURES ("interface-output"),
+};
+
+VLIB_REGISTER_NODE (acl_out_fa_ip4_node) =
+{
+  .function = acl_out_ip4_fa_node_fn,
+  .name = "acl-plugin-out-ip4-fa",
+  .vector_size = sizeof (u32),
+  .format_trace = format_acl_plugin_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (acl_fa_error_strings),
+  .error_strings = acl_fa_error_strings,
+  .n_next_nodes = ACL_FA_N_NEXT,
+    /* edit / add dispositions here */
+  .next_nodes =
+  {
+    [ACL_FA_ERROR_DROP] = "error-drop",
+  }
+};
+
+VNET_FEATURE_INIT (acl_out_ip4_fa_feature, static) =
+{
+  .arc_name = "ip4-output",
+  .node_name = "acl-plugin-out-ip4-fa",
+  .runs_before = VNET_FEATURES ("interface-output"),
+};
+#endif
+
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/acl/fa_node.c b/src/plugins/acl/fa_node.c
deleted file mode 100644
index a36a581532b..00000000000
--- a/src/plugins/acl/fa_node.c
+++ /dev/null
@@ -1,1614 +0,0 @@
-/*
- * Copyright (c) 2016 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#include <stddef.h>
-#include <netinet/in.h>
-
-#include <vlib/vlib.h>
-#include <vnet/vnet.h>
-#include <vnet/pg/pg.h>
-#include <vppinfra/error.h>
-
-
-#include <acl/acl.h>
-#include <vnet/ip/icmp46_packet.h>
-
-#include <plugins/acl/fa_node.h>
-#include <plugins/acl/acl.h>
-#include <plugins/acl/lookup_context.h>
-#include <plugins/acl/public_inlines.h>
-
-#include <vppinfra/bihash_40_8.h>
-#include <vppinfra/bihash_template.h>
-#include <vppinfra/bihash_template.c>
-
-typedef struct
-{
-  u32 next_index;
-  u32 sw_if_index;
-  u32 lc_index;
-  u32 match_acl_in_index;
-  u32 match_rule_index;
-  u64 packet_info[6];
-  u32 trace_bitmap;
-  u8 action;
-} acl_fa_trace_t;
-
-/* ICMPv4 invert type for stateful ACL */
-static const u8 icmp4_invmap[] = {
-  [ICMP4_echo_reply] = ICMP4_echo_request + 1,
-  [ICMP4_timestamp_reply] = ICMP4_timestamp_request + 1,
-  [ICMP4_information_reply] = ICMP4_information_request + 1,
-  [ICMP4_address_mask_reply] = ICMP4_address_mask_request + 1
-};
-
-/* Supported ICMPv4 messages for session creation */
-static const u8 icmp4_valid_new[] = {
-  [ICMP4_echo_request] = 1,
-  [ICMP4_timestamp_request] = 1,
-  [ICMP4_information_request] = 1,
-  [ICMP4_address_mask_request] = 1
-};
-
-/* ICMPv6 invert type for stateful ACL */
-static const u8 icmp6_invmap[] = {
-  [ICMP6_echo_reply - 128]   = ICMP6_echo_request + 1,
-  [ICMP6_node_information_response - 128] = ICMP6_node_information_request + 1
-};
-
-/* Supported ICMPv6 messages for session creation */
-static const u8 icmp6_valid_new[] = {
-  [ICMP6_echo_request - 128] = 1,
-  [ICMP6_node_information_request - 128] = 1
-};
-
-/* IP4 and IP6 protocol numbers of ICMP */
-static u8 icmp_protos[] = { IP_PROTOCOL_ICMP, IP_PROTOCOL_ICMP6 };
-
-static u8 *
-format_fa_5tuple (u8 * s, va_list * args)
-{
-  fa_5tuple_t *p5t = va_arg (*args, fa_5tuple_t *);
-
-  return format(s, "lc_index %d (lsb16 of sw_if_index %d) l3 %s%s %U -> %U"
-                   " l4 proto %d l4_valid %d port %d -> %d tcp flags (%s) %02x rsvd %x",
-                p5t->pkt.lc_index, p5t->l4.lsb_of_sw_if_index, p5t->pkt.is_ip6 ? "ip6" : "ip4",
-                p5t->pkt.is_nonfirst_fragment ? " non-initial fragment" : "",
-                format_ip46_address, &p5t->addr[0], p5t->pkt.is_ip6 ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
-                format_ip46_address, &p5t->addr[1], p5t->pkt.is_ip6 ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
-                p5t->l4.proto, p5t->pkt.l4_valid,
-                p5t->l4.port[0], p5t->l4.port[1],
-                p5t->pkt.tcp_flags_valid ? "valid": "invalid",
-                p5t->pkt.tcp_flags,
-                p5t->pkt.flags_reserved);
-}
-
-u8 *
-format_acl_plugin_5tuple (u8 * s, va_list * args)
-{
-  return format_fa_5tuple(s, args);
-}
-
-/* packet trace format function */
-static u8 *
-format_acl_fa_trace (u8 * s, va_list * args)
-{
-  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
-  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
-  acl_fa_trace_t *t = va_arg (*args, acl_fa_trace_t *);
-
-  s =
-    format (s,
-	    "acl-plugin: lc_index: %d, sw_if_index %d, next index %d, action: %d, match: acl %d rule %d trace_bits %08x\n"
-	    "  pkt info %016llx %016llx %016llx %016llx %016llx %016llx",
-	    t->lc_index, t->sw_if_index, t->next_index, t->action, t->match_acl_in_index,
-	    t->match_rule_index, t->trace_bitmap,
-	    t->packet_info[0], t->packet_info[1], t->packet_info[2],
-	    t->packet_info[3], t->packet_info[4], t->packet_info[5]);
-
-  /* Now also print out the packet_info in a form usable by humans */
-  s = format (s, "\n   %U", format_fa_5tuple, t->packet_info);
-  return s;
-}
-
-/* *INDENT-OFF* */
-#define foreach_acl_fa_error \
-_(ACL_DROP, "ACL deny packets")  \
-_(ACL_PERMIT, "ACL permit packets")  \
-_(ACL_NEW_SESSION, "new sessions added") \
-_(ACL_EXIST_SESSION, "existing session packets") \
-_(ACL_CHECK, "checked packets") \
-_(ACL_RESTART_SESSION_TIMER, "restart session timer") \
-_(ACL_TOO_MANY_SESSIONS, "too many sessions to add new") \
-/* end  of errors */
-
-typedef enum
-{
-#define _(sym,str) ACL_FA_ERROR_##sym,
-  foreach_acl_fa_error
-#undef _
-    ACL_FA_N_ERROR,
-} acl_fa_error_t;
-
-static char *acl_fa_error_strings[] = {
-#define _(sym,string) string,
-  foreach_acl_fa_error
-#undef _
-};
-/* *INDENT-ON* */
-
-static int
-acl_fa_ifc_has_sessions (acl_main_t * am, int sw_if_index0)
-{
-  return am->fa_sessions_hash_is_initialized;
-}
-
-static int
-acl_fa_ifc_has_in_acl (acl_main_t * am, int sw_if_index0)
-{
-  int it_has = clib_bitmap_get (am->fa_in_acl_on_sw_if_index, sw_if_index0);
-  return it_has;
-}
-
-static int
-acl_fa_ifc_has_out_acl (acl_main_t * am, int sw_if_index0)
-{
-  int it_has = clib_bitmap_get (am->fa_out_acl_on_sw_if_index, sw_if_index0);
-  return it_has;
-}
-
-/* Session keys match the packets received, and mirror the packets sent */
-static u32
-acl_make_5tuple_session_key (acl_main_t * am, int is_input, int is_ip6,
-                             u32 sw_if_index, fa_5tuple_t * p5tuple_pkt,
-                             fa_5tuple_t * p5tuple_sess)
-{
-  int src_index = is_input ? 0 : 1;
-  int dst_index = is_input ? 1 : 0;
-  u32 valid_new_sess = 1;
-  p5tuple_sess->addr[src_index] = p5tuple_pkt->addr[0];
-  p5tuple_sess->addr[dst_index] = p5tuple_pkt->addr[1];
-  p5tuple_sess->l4.as_u64 = p5tuple_pkt->l4.as_u64;
-
-  if (PREDICT_TRUE(p5tuple_pkt->l4.proto != icmp_protos[is_ip6]))
-    {
-      p5tuple_sess->l4.port[src_index] = p5tuple_pkt->l4.port[0];
-      p5tuple_sess->l4.port[dst_index] = p5tuple_pkt->l4.port[1];
-    }
-  else
-    {
-      static const u8 * icmp_invmap[] = { icmp4_invmap, icmp6_invmap };
-      static const u8 * icmp_valid_new[] = { icmp4_valid_new, icmp6_valid_new };
-      static const u8 icmp_invmap_size[] = { sizeof(icmp4_invmap),
-                                             sizeof(icmp6_invmap) };
-      static const u8 icmp_valid_new_size[] = { sizeof(icmp4_valid_new),
-                                                sizeof(icmp6_valid_new) };
-      int type = is_ip6 ? p5tuple_pkt->l4.port[0]-128: p5tuple_pkt->l4.port[0];
-
-      p5tuple_sess->l4.port[0] = p5tuple_pkt->l4.port[0];
-      p5tuple_sess->l4.port[1] = p5tuple_pkt->l4.port[1];
-
-      /*
-       * Invert ICMP type for valid icmp_invmap messages:
-       *  1) input node with outbound ACL interface
-       *  2) output node with inbound ACL interface
-       *
-       */
-      if ((is_input && acl_fa_ifc_has_out_acl(am, sw_if_index)) ||
-          (!is_input && acl_fa_ifc_has_in_acl(am, sw_if_index)))
-        {
-          if (type >= 0 &&
-              type <= icmp_invmap_size[is_ip6] &&
-              icmp_invmap[is_ip6][type])
-            {
-              p5tuple_sess->l4.port[0] = icmp_invmap[is_ip6][type] - 1;
-            }
-        }
-
-      /*
-       * ONLY ICMP messages defined in icmp4_valid_new/icmp6_valid_new table
-       * are allowed to create stateful ACL.
-       * The other messages will be forwarded without creating a reflexive ACL.
-       */
-      if (type < 0 ||
-          type > icmp_valid_new_size[is_ip6] ||
-          !icmp_valid_new[is_ip6][type])
-        {
-          valid_new_sess = 0;
-        }
-    }
-
-    return valid_new_sess;
-}
-
-
-static int
-fa_session_get_timeout_type (acl_main_t * am, fa_session_t * sess)
-{
-  /* seen both SYNs and ACKs but not FINs means we are in establshed state */
-  u16 masked_flags =
-    sess->tcp_flags_seen.as_u16 & ((TCP_FLAGS_RSTFINACKSYN << 8) +
-				   TCP_FLAGS_RSTFINACKSYN);
-  switch (sess->info.l4.proto)
-    {
-    case IPPROTO_TCP:
-      if (((TCP_FLAGS_ACKSYN << 8) + TCP_FLAGS_ACKSYN) == masked_flags)
-	{
-	  return ACL_TIMEOUT_TCP_IDLE;
-	}
-      else
-	{
-	  return ACL_TIMEOUT_TCP_TRANSIENT;
-	}
-      break;
-    case IPPROTO_UDP:
-      return ACL_TIMEOUT_UDP_IDLE;
-      break;
-    default:
-      return ACL_TIMEOUT_UDP_IDLE;
-    }
-}
-
-
-static u64
-fa_session_get_shortest_timeout(acl_main_t * am)
-{
-  int timeout_type;
-  u64 timeout = ~0LL;
-  for(timeout_type = 0; timeout_type < ACL_N_TIMEOUTS; timeout_type++) {
-    if (timeout > am->session_timeout_sec[timeout_type]) {
-      timeout = am->session_timeout_sec[timeout_type];
-    }
-  }
-  return timeout;
-}
-
-/*
- * Get the timeout of the session in a list since its enqueue time.
- */
-
-static u64
-fa_session_get_list_timeout (acl_main_t * am, fa_session_t * sess)
-{
-  u64 timeout = am->vlib_main->clib_time.clocks_per_second;
-  /*
-   * we have the shortest possible timeout type in all the lists
-   * (see README-multicore for the rationale)
-   */
-  timeout *= fa_session_get_shortest_timeout(am);
-  return timeout;
-}
-
-/*
- * Get the idle timeout of a session.
- */
-
-static u64
-fa_session_get_timeout (acl_main_t * am, fa_session_t * sess)
-{
-  u64 timeout = am->vlib_main->clib_time.clocks_per_second;
-  int timeout_type = fa_session_get_timeout_type (am, sess);
-  timeout *= am->session_timeout_sec[timeout_type];
-  return timeout;
-}
-
-static void
-acl_fa_verify_init_sessions (acl_main_t * am)
-{
-  if (!am->fa_sessions_hash_is_initialized) {
-    u16 wk;
-    /* Allocate the per-worker sessions pools */
-    for (wk = 0; wk < vec_len (am->per_worker_data); wk++) {
-      acl_fa_per_worker_data_t *pw = &am->per_worker_data[wk];
-
-      /*
-      * // In lieu of trying to preallocate the pool and its free bitmap, rather use pool_init_fixed
-      * pool_alloc_aligned(pw->fa_sessions_pool, am->fa_conn_table_max_entries, CLIB_CACHE_LINE_BYTES);
-      * clib_bitmap_validate(pool_header(pw->fa_sessions_pool)->free_bitmap, am->fa_conn_table_max_entries);
-      */
-      pool_init_fixed(pw->fa_sessions_pool, am->fa_conn_table_max_entries);
-    }
-
-    /* ... and the interface session hash table */
-    BV (clib_bihash_init) (&am->fa_sessions_hash,
-			 "ACL plugin FA session bihash",
-			 am->fa_conn_table_hash_num_buckets,
-			 am->fa_conn_table_hash_memory_size);
-    am->fa_sessions_hash_is_initialized = 1;
-  }
-}
-
-static inline fa_session_t *get_session_ptr(acl_main_t *am, u16 thread_index, u32 session_index)
-{
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  fa_session_t *sess = pool_is_free_index (pw->fa_sessions_pool, session_index) ? 0 : pool_elt_at_index(pw->fa_sessions_pool, session_index);
-  return sess;
-}
-
-static inline int is_valid_session_ptr(acl_main_t *am, u16 thread_index, fa_session_t *sess)
-{
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  return ((sess != 0) && ((sess - pw->fa_sessions_pool) < pool_len(pw->fa_sessions_pool)));
-}
-
-static void
-acl_fa_conn_list_add_session (acl_main_t * am, fa_full_session_id_t sess_id, u64 now)
-{
-  fa_session_t *sess = get_session_ptr(am, sess_id.thread_index, sess_id.session_index);
-  u8 list_id = fa_session_get_timeout_type(am, sess);
-  uword thread_index = os_get_thread_index ();
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  /* the retrieved session thread index must be necessarily the same as the one in the key */
-  ASSERT (sess->thread_index == sess_id.thread_index);
-  /* the retrieved session thread index must be the same as current thread */
-  ASSERT (sess->thread_index == thread_index);
-  sess->link_enqueue_time = now;
-  sess->link_list_id = list_id;
-  sess->link_next_idx = ~0;
-  sess->link_prev_idx = pw->fa_conn_list_tail[list_id];
-  if (~0 != pw->fa_conn_list_tail[list_id]) {
-    fa_session_t *prev_sess = get_session_ptr(am, thread_index, pw->fa_conn_list_tail[list_id]);
-    prev_sess->link_next_idx = sess_id.session_index;
-    /* We should never try to link with a session on another thread */
-    ASSERT(prev_sess->thread_index == sess->thread_index);
-  }
-  pw->fa_conn_list_tail[list_id] = sess_id.session_index;
-  
-#ifdef FA_NODE_VERBOSE_DEBUG
-    clib_warning("FA-SESSION-DEBUG: add session id %d on thread %d sw_if_index %d", sess_id.session_index, thread_index, sess->sw_if_index);
-#endif
-  pw->serviced_sw_if_index_bitmap = clib_bitmap_set(pw->serviced_sw_if_index_bitmap, sess->sw_if_index, 1);
-
-  if (~0 == pw->fa_conn_list_head[list_id]) {
-    pw->fa_conn_list_head[list_id] = sess_id.session_index;
-  }
-}
-
-static int
-acl_fa_conn_list_delete_session (acl_main_t *am, fa_full_session_id_t sess_id)
-{
-  uword thread_index = os_get_thread_index ();
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  if (thread_index != sess_id.thread_index) {
-    /* If another thread attempts to delete the session, fail it. */
-#ifdef FA_NODE_VERBOSE_DEBUG
-    clib_warning("thread id in key %d != curr thread index, not deleting");
-#endif
-    return 0;
-  }
-  fa_session_t *sess = get_session_ptr(am, sess_id.thread_index, sess_id.session_index);
-  /* we should never try to delete the session with another thread index */
-  ASSERT(sess->thread_index == thread_index);
-  if (~0 != sess->link_prev_idx) {
-    fa_session_t *prev_sess = get_session_ptr(am, thread_index, sess->link_prev_idx);
-    /* the previous session must be in the same list as this one */
-    ASSERT(prev_sess->link_list_id == sess->link_list_id);
-    prev_sess->link_next_idx = sess->link_next_idx;
-  }
-  if (~0 != sess->link_next_idx) {
-    fa_session_t *next_sess = get_session_ptr(am, thread_index, sess->link_next_idx);
-    /* The next session must be in the same list as the one we are deleting */
-    ASSERT(next_sess->link_list_id == sess->link_list_id);
-    next_sess->link_prev_idx = sess->link_prev_idx;
-  }
-  if (pw->fa_conn_list_head[sess->link_list_id] == sess_id.session_index) {
-    pw->fa_conn_list_head[sess->link_list_id] = sess->link_next_idx;
-  }
-  if (pw->fa_conn_list_tail[sess->link_list_id] == sess_id.session_index) {
-    pw->fa_conn_list_tail[sess->link_list_id] = sess->link_prev_idx;
-  }
-  return 1;
-}
-
-static int
-acl_fa_restart_timer_for_session (acl_main_t * am, u64 now, fa_full_session_id_t sess_id)
-{
-  if (acl_fa_conn_list_delete_session(am, sess_id)) {
-    acl_fa_conn_list_add_session(am, sess_id, now);
-    return 1;
-  } else {
-    /*
-     * Our thread does not own this connection, so we can not delete
-     * The session. To avoid the complicated signaling, we simply
-     * pick the list waiting time to be the shortest of the timeouts.
-     * This way we do not have to do anything special, and let
-     * the regular requeue check take care of everything.
-     */
-    return 0;
-  }
-}
-
-
-static u8
-acl_fa_track_session (acl_main_t * am, int is_input, u32 sw_if_index, u64 now,
-		      fa_session_t * sess, fa_5tuple_t * pkt_5tuple)
-{
-  sess->last_active_time = now;
-  if (pkt_5tuple->pkt.tcp_flags_valid)
-    {
-      sess->tcp_flags_seen.as_u8[is_input] |= pkt_5tuple->pkt.tcp_flags;
-    }
-  return 3;
-}
-
-
-static void
-acl_fa_delete_session (acl_main_t * am, u32 sw_if_index, fa_full_session_id_t sess_id)
-{
-  void *oldheap = clib_mem_set_heap(am->acl_mheap);
-  fa_session_t *sess = get_session_ptr(am, sess_id.thread_index, sess_id.session_index);
-  ASSERT(sess->thread_index == os_get_thread_index ());
-  BV (clib_bihash_add_del) (&am->fa_sessions_hash,
-			    &sess->info.kv, 0);
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[sess_id.thread_index];
-  pool_put_index (pw->fa_sessions_pool, sess_id.session_index);
-  /* Deleting from timer structures not needed,
-     as the caller must have dealt with the timers. */
-  vec_validate (pw->fa_session_dels_by_sw_if_index, sw_if_index);
-  clib_mem_set_heap (oldheap);
-  pw->fa_session_dels_by_sw_if_index[sw_if_index]++;
-  clib_smp_atomic_add(&am->fa_session_total_dels, 1);
-}
-
-static int
-acl_fa_can_add_session (acl_main_t * am, int is_input, u32 sw_if_index)
-{
-  u64 curr_sess_count;
-  curr_sess_count = am->fa_session_total_adds - am->fa_session_total_dels;
-  return (curr_sess_count < am->fa_conn_table_max_entries);
-}
-
-static u64
-acl_fa_get_list_head_expiry_time(acl_main_t *am, acl_fa_per_worker_data_t *pw, u64 now, u16 thread_index, int timeout_type)
-{
-  fa_session_t *sess = get_session_ptr(am, thread_index, pw->fa_conn_list_head[timeout_type]);
-  /*
-   * We can not check just the index here because inbetween the worker thread might
-   * dequeue the connection from the head just as we are about to check it.
-   */
-  if (!is_valid_session_ptr(am, thread_index, sess)) {
-    return ~0LL; // infinity.
-  } else {
-    u64 timeout_time =
-              sess->link_enqueue_time + fa_session_get_list_timeout (am, sess);
-    return timeout_time;
-  }
-}
-
-static int
-acl_fa_conn_time_to_check (acl_main_t *am, acl_fa_per_worker_data_t *pw, u64 now, u16 thread_index, u32 session_index)
-{
-  fa_session_t *sess = get_session_ptr(am, thread_index, session_index);
-  u64 timeout_time =
-              sess->link_enqueue_time + fa_session_get_list_timeout (am, sess);
-  return (timeout_time < now) || (sess->link_enqueue_time <= pw->swipe_end_time);
-}
-
-/*
- * see if there are sessions ready to be checked,
- * do the maintenance (requeue or delete), and
- * return the total number of sessions reclaimed.
- */
-static int
-acl_fa_check_idle_sessions(acl_main_t *am, u16 thread_index, u64 now)
-{
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  fa_full_session_id_t fsid;
-  fsid.thread_index = thread_index;
-  int total_expired = 0;
-
-  {
-    u8 tt = 0;
-    for(tt = 0; tt < ACL_N_TIMEOUTS; tt++) {
-      while((vec_len(pw->expired) < am->fa_max_deleted_sessions_per_interval)
-	    && (~0 != pw->fa_conn_list_head[tt])
-	    && (acl_fa_conn_time_to_check(am, pw, now, thread_index,
-					  pw->fa_conn_list_head[tt]))) {
-	fsid.session_index = pw->fa_conn_list_head[tt];
-        elog_acl_maybe_trace_X2(am, "acl_fa_check_idle_sessions: expire session %d on thread %d", "i4i4", (u32)fsid.session_index, (u32)thread_index);
-	vec_add1(pw->expired, fsid.session_index);
-	acl_fa_conn_list_delete_session(am, fsid);
-      }
-    }
-  }
-
-  u32 *psid = NULL;
-  vec_foreach (psid, pw->expired)
-  {
-    fsid.session_index = *psid;
-    if (!pool_is_free_index (pw->fa_sessions_pool, fsid.session_index))
-      {
-	fa_session_t *sess = get_session_ptr(am, thread_index, fsid.session_index);
-	u32 sw_if_index = sess->sw_if_index;
-	u64 sess_timeout_time =
-	  sess->last_active_time + fa_session_get_timeout (am, sess);
-	if ((now < sess_timeout_time) && (0 == clib_bitmap_get(pw->pending_clear_sw_if_index_bitmap, sw_if_index)))
-	  {
-#ifdef FA_NODE_VERBOSE_DEBUG
-	    clib_warning ("ACL_FA_NODE_CLEAN: Restarting timer for session %d, sw_if_index %d",
-	       (int) fsid.session_index, sess->sw_if_index);
-#endif
-	    /* There was activity on the session, so the idle timeout
-	       has not passed. Enqueue for another time period. */
-
-	    acl_fa_conn_list_add_session(am, fsid, now);
-	    pw->cnt_session_timer_restarted++;
-	  }
-	else
-	  {
-#ifdef FA_NODE_VERBOSE_DEBUG
-	    clib_warning ("ACL_FA_NODE_CLEAN: Deleting session %d, sw_if_index %d",
-	       (int) fsid.session_index, sess->sw_if_index);
-#endif
-	    acl_fa_delete_session (am, sw_if_index, fsid);
-	    pw->cnt_deleted_sessions++;
-	  }
-      }
-    else
-      {
-	pw->cnt_already_deleted_sessions++;
-      }
-  }
-  total_expired = vec_len(pw->expired);
-  /* zero out the vector which we have acted on */
-  if (pw->expired)
-    _vec_len (pw->expired) = 0;
-  /* if we were advancing and reached the end
-   * (no more sessions to recycle), reset the fast-forward timestamp */
-
-  if (pw->swipe_end_time && 0 == total_expired)
-    pw->swipe_end_time = 0;
-  return (total_expired);
-}
-
-always_inline void
-acl_fa_try_recycle_session (acl_main_t * am, int is_input, u16 thread_index, u32 sw_if_index)
-{
-  /* try to recycle a TCP transient session */
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  u8 timeout_type = ACL_TIMEOUT_TCP_TRANSIENT;
-  fa_full_session_id_t sess_id;
-  sess_id.session_index = pw->fa_conn_list_head[timeout_type];
-  if (~0 != sess_id.session_index) {
-    sess_id.thread_index = thread_index;
-    acl_fa_conn_list_delete_session(am, sess_id);
-    acl_fa_delete_session(am, sw_if_index, sess_id);
-  }
-}
-
-static fa_session_t *
-acl_fa_add_session (acl_main_t * am, int is_input, u32 sw_if_index, u64 now,
-		    fa_5tuple_t * p5tuple, u16 current_policy_epoch)
-{
-  clib_bihash_kv_40_8_t *pkv = &p5tuple->kv;
-  clib_bihash_kv_40_8_t kv;
-  fa_full_session_id_t f_sess_id;
-  uword thread_index = os_get_thread_index();
-  void *oldheap = clib_mem_set_heap(am->acl_mheap);
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-
-  f_sess_id.thread_index = thread_index;
-  fa_session_t *sess;
-
-  pool_get_aligned (pw->fa_sessions_pool, sess, CLIB_CACHE_LINE_BYTES);
-  f_sess_id.session_index = sess - pw->fa_sessions_pool;
-  f_sess_id.intf_policy_epoch = current_policy_epoch;
-
-  kv.key[0] = pkv->key[0];
-  kv.key[1] = pkv->key[1];
-  kv.key[2] = pkv->key[2];
-  kv.key[3] = pkv->key[3];
-  kv.key[4] = pkv->key[4];
-  kv.value = f_sess_id.as_u64;
-
-  memcpy (sess, pkv, sizeof (pkv->key));
-  sess->last_active_time = now;
-  sess->sw_if_index = sw_if_index;
-  sess->tcp_flags_seen.as_u16 = 0;
-  sess->thread_index = thread_index;
-  sess->link_list_id = ~0;
-  sess->link_prev_idx = ~0;
-  sess->link_next_idx = ~0;
-
-
-
-  ASSERT(am->fa_sessions_hash_is_initialized == 1);
-  BV (clib_bihash_add_del) (&am->fa_sessions_hash,
-			    &kv, 1);
-  acl_fa_conn_list_add_session(am, f_sess_id, now);
-
-  vec_validate (pw->fa_session_adds_by_sw_if_index, sw_if_index);
-  clib_mem_set_heap (oldheap);
-  pw->fa_session_adds_by_sw_if_index[sw_if_index]++;
-  clib_smp_atomic_add(&am->fa_session_total_adds, 1);
-  return sess;
-}
-
-static int
-acl_fa_find_session (acl_main_t * am, u32 sw_if_index0, fa_5tuple_t * p5tuple,
-		     clib_bihash_kv_40_8_t * pvalue_sess)
-{
-  return (clib_bihash_search_40_8 (&am->fa_sessions_hash, &p5tuple->kv, pvalue_sess) == 0);
-}
-
-
-always_inline uword
-acl_fa_node_fn (vlib_main_t * vm,
-		vlib_node_runtime_t * node, vlib_frame_t * frame, int is_ip6,
-		int is_input, int is_l2_path, u32 * l2_feat_next_node_index,
-		vlib_node_registration_t * acl_fa_node)
-{
-  u32 n_left_from, *from, *to_next;
-  acl_fa_next_t next_index;
-  u32 pkts_acl_checked = 0;
-  u32 pkts_new_session = 0;
-  u32 pkts_exist_session = 0;
-  u32 pkts_acl_permit = 0;
-  u32 pkts_restart_session_timer = 0;
-  u32 trace_bitmap = 0;
-  acl_main_t *am = &acl_main;
-  fa_5tuple_t fa_5tuple, kv_sess;
-  clib_bihash_kv_40_8_t value_sess;
-  vlib_node_runtime_t *error_node;
-  u64 now = clib_cpu_time_now ();
-  uword thread_index = os_get_thread_index ();
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-
-  from = vlib_frame_vector_args (frame);
-  n_left_from = frame->n_vectors;
-  next_index = node->cached_next_index;
-
-  error_node = vlib_node_get_runtime (vm, acl_fa_node->index);
-
-  while (n_left_from > 0)
-    {
-      u32 n_left_to_next;
-
-      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
-
-      while (n_left_from > 0 && n_left_to_next > 0)
-	{
-	  u32 bi0;
-	  vlib_buffer_t *b0;
-	  u32 next0 = 0;
-	  u8 action = 0;
-	  u32 sw_if_index0;
-	  u32 lc_index0;
-	  int acl_check_needed = 1;
-	  u32 match_acl_in_index = ~0;
-	  u32 match_acl_pos = ~0;
-	  u32 match_rule_index = ~0;
-	  u8 error0 = 0;
-	  u32 valid_new_sess;
-
-	  /* speculatively enqueue b0 to the current next frame */
-	  bi0 = from[0];
-	  to_next[0] = bi0;
-	  from += 1;
-	  to_next += 1;
-	  n_left_from -= 1;
-	  n_left_to_next -= 1;
-
-	  b0 = vlib_get_buffer (vm, bi0);
-
-	  if (is_input)
-	    sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-	  else
-	    sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
-
-	  if (is_input)
-	    lc_index0 = am->input_lc_index_by_sw_if_index[sw_if_index0];
-	  else
-	    lc_index0 = am->output_lc_index_by_sw_if_index[sw_if_index0];
-
-          u32 **p_epoch_vec = is_input ? &am->input_policy_epoch_by_sw_if_index
-                                       :  &am->output_policy_epoch_by_sw_if_index;
-          u16 current_policy_epoch = sw_if_index0 < vec_len(*p_epoch_vec) ? vec_elt(*p_epoch_vec, sw_if_index0) : (is_input * FA_POLICY_EPOCH_IS_INPUT);
-	  /*
-	   * Extract the L3/L4 matching info into a 5-tuple structure,
-	   * then create a session key whose layout is independent on forward or reverse
-	   * direction of the packet.
-	   */
-
-	  acl_plugin_fill_5tuple_inline (lc_index0, b0, is_ip6, is_input, is_l2_path, (fa_5tuple_opaque_t *)&fa_5tuple);
-          fa_5tuple.l4.lsb_of_sw_if_index = sw_if_index0 & 0xffff;
-	  valid_new_sess = acl_make_5tuple_session_key (am, is_input, is_ip6, sw_if_index0,  &fa_5tuple, &kv_sess);
-          // XXDEL fa_5tuple.pkt.is_input = is_input;
-          fa_5tuple.pkt.mask_type_index_lsb = ~0;
-#ifdef FA_NODE_VERBOSE_DEBUG
-	  clib_warning
-	    ("ACL_FA_NODE_DBG: session 5-tuple %016llx %016llx %016llx %016llx %016llx %016llx",
-	     kv_sess.kv.key[0], kv_sess.kv.key[1], kv_sess.kv.key[2],
-	     kv_sess.kv.key[3], kv_sess.kv.key[4], kv_sess.kv.value);
-	  clib_warning
-	    ("ACL_FA_NODE_DBG: packet 5-tuple %016llx %016llx %016llx %016llx %016llx %016llx",
-	     fa_5tuple.kv.key[0], fa_5tuple.kv.key[1], fa_5tuple.kv.key[2],
-	     fa_5tuple.kv.key[3], fa_5tuple.kv.key[4], fa_5tuple.kv.value);
-#endif
-
-	  /* Try to match an existing session first */
-
-	  if (acl_fa_ifc_has_sessions (am, sw_if_index0))
-	    {
-	      if (acl_fa_find_session
-		  (am, sw_if_index0, &kv_sess, &value_sess))
-		{
-		  trace_bitmap |= 0x80000000;
-		  error0 = ACL_FA_ERROR_ACL_EXIST_SESSION;
-		  fa_full_session_id_t f_sess_id;
-
-                  f_sess_id.as_u64 = value_sess.value;
-                  ASSERT(f_sess_id.thread_index < vec_len(vlib_mains));
-
-		  fa_session_t *sess = get_session_ptr(am, f_sess_id.thread_index, f_sess_id.session_index);
-		  int old_timeout_type =
-		    fa_session_get_timeout_type (am, sess);
-		  action =
-		    acl_fa_track_session (am, is_input, sw_if_index0, now,
-					  sess, &fa_5tuple);
-		  /* expose the session id to the tracer */
-		  match_rule_index = f_sess_id.session_index;
-		  int new_timeout_type =
-		    fa_session_get_timeout_type (am, sess);
-		  acl_check_needed = 0;
-		  pkts_exist_session += 1;
-		  /* Tracking might have changed the session timeout type, e.g. from transient to established */
-		  if (PREDICT_FALSE (old_timeout_type != new_timeout_type))
-		    {
-		      acl_fa_restart_timer_for_session (am, now, f_sess_id);
-		      pkts_restart_session_timer++;
-		      trace_bitmap |=
-			0x00010000 + ((0xff & old_timeout_type) << 8) +
-			(0xff & new_timeout_type);
-		    }
-                  /*
-                   * I estimate the likelihood to be very low - the VPP needs
-                   * to have >64K interfaces to start with and then on
-                   * exactly 64K indices apart needs to be exactly the same
-                   * 5-tuple... Anyway, since this probability is nonzero -
-                   * print an error and drop the unlucky packet.
-                   * If this shows up in real world, we would need to bump
-                   * the hash key length.
-                   */
-		  if (PREDICT_FALSE(sess->sw_if_index != sw_if_index0)) {
-                    clib_warning("BUG: session LSB16(sw_if_index) and 5-tuple collision!");
-                    acl_check_needed = 0;
-                    action = 0;
-                  }
-                  if (PREDICT_FALSE(am->reclassify_sessions)) {
-                   /* if the MSB of policy epoch matches but not the LSB means it is a stale session */
-                   if ( (0 == ((current_policy_epoch ^ f_sess_id.intf_policy_epoch) & FA_POLICY_EPOCH_IS_INPUT))
-                        && (current_policy_epoch != f_sess_id.intf_policy_epoch) ) {
-                      /* delete session and increment the counter */
-                      vec_validate (pw->fa_session_epoch_change_by_sw_if_index, sw_if_index0);
-                      vec_elt (pw->fa_session_epoch_change_by_sw_if_index, sw_if_index0)++;
-                      if(acl_fa_conn_list_delete_session(am, f_sess_id)) {
-                        /* delete the session only if we were able to unlink it */
-                        acl_fa_delete_session (am, sw_if_index0, f_sess_id);
-                      }
-                      acl_check_needed = 1;
-                      trace_bitmap |= 0x40000000;
-                    }
-                  }
-		}
-	    }
-
-	  if (acl_check_needed)
-	    {
-              action = 0; /* deny by default */
-	      acl_plugin_match_5tuple_inline (lc_index0, (fa_5tuple_opaque_t *)&fa_5tuple,
-				       is_ip6, &action, &match_acl_pos, &match_acl_in_index,
-				       &match_rule_index, &trace_bitmap);
-	      error0 = action;
-	      if (1 == action)
-		pkts_acl_permit += 1;
-	      if (2 == action)
-		{
-		  if (!acl_fa_can_add_session (am, is_input, sw_if_index0))
-                    acl_fa_try_recycle_session (am, is_input, thread_index, sw_if_index0);
-
-		  if (acl_fa_can_add_session (am, is_input, sw_if_index0))
-		    {
-                      if (PREDICT_TRUE (valid_new_sess)) {
-                        fa_session_t *sess = acl_fa_add_session (am, is_input,
-                                                                 sw_if_index0,
-                                                                 now, &kv_sess, current_policy_epoch);
-                        acl_fa_track_session (am, is_input, sw_if_index0, now,
-                                              sess, &fa_5tuple);
-                        pkts_new_session += 1;
-                      } else {
-                        /*
-                         *  ICMP packets with non-icmp_valid_new type will be
-                         *  forwared without being dropped.
-                         */
-                        action = 1;
-                        pkts_acl_permit += 1;
-                      }
-		    }
-		  else
-		    {
-		      action = 0;
-		      error0 = ACL_FA_ERROR_ACL_TOO_MANY_SESSIONS;
-		    }
-		}
-	    }
-
-
-
-	  if (action > 0)
-	    {
-	      if (is_l2_path)
-		next0 = vnet_l2_feature_next (b0, l2_feat_next_node_index, 0);
-	      else
-		vnet_feature_next (sw_if_index0, &next0, b0);
-	    }
-#ifdef FA_NODE_VERBOSE_DEBUG
-          clib_warning("ACL_FA_NODE_DBG: sw_if_index %d lc_index %d action %d acl_index %d rule_index %d", sw_if_index0, lc_index0, action, match_acl_in_index, match_rule_index);
-#endif
-
-	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
-			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-	    {
-	      acl_fa_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
-	      t->sw_if_index = sw_if_index0;
-	      t->lc_index = lc_index0;
-	      t->next_index = next0;
-	      t->match_acl_in_index = match_acl_in_index;
-	      t->match_rule_index = match_rule_index;
-	      t->packet_info[0] = fa_5tuple.kv.key[0];
-	      t->packet_info[1] = fa_5tuple.kv.key[1];
-	      t->packet_info[2] = fa_5tuple.kv.key[2];
-	      t->packet_info[3] = fa_5tuple.kv.key[3];
-	      t->packet_info[4] = fa_5tuple.kv.key[4];
-	      t->packet_info[5] = fa_5tuple.kv.value;
-	      t->action = action;
-	      t->trace_bitmap = trace_bitmap;
-	    }
-
-	  next0 = next0 < node->n_next_nodes ? next0 : 0;
-	  if (0 == next0)
-	    b0->error = error_node->errors[error0];
-
-	  pkts_acl_checked += 1;
-
-	  /* verify speculative enqueue, maybe switch current next frame */
-	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
-					   to_next, n_left_to_next, bi0,
-					   next0);
-	}
-
-      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
-    }
-
-  vlib_node_increment_counter (vm, acl_fa_node->index,
-			       ACL_FA_ERROR_ACL_CHECK, pkts_acl_checked);
-  vlib_node_increment_counter (vm, acl_fa_node->index,
-			       ACL_FA_ERROR_ACL_PERMIT, pkts_acl_permit);
-  vlib_node_increment_counter (vm, acl_fa_node->index,
-			       ACL_FA_ERROR_ACL_NEW_SESSION,
-			       pkts_new_session);
-  vlib_node_increment_counter (vm, acl_fa_node->index,
-			       ACL_FA_ERROR_ACL_EXIST_SESSION,
-			       pkts_exist_session);
-  vlib_node_increment_counter (vm, acl_fa_node->index,
-			       ACL_FA_ERROR_ACL_RESTART_SESSION_TIMER,
-			       pkts_restart_session_timer);
-  return frame->n_vectors;
-}
-
-
-vlib_node_registration_t acl_in_l2_ip6_node;
-static uword
-acl_in_ip6_l2_node_fn (vlib_main_t * vm,
-		       vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  acl_main_t *am = &acl_main;
-  return acl_fa_node_fn (vm, node, frame, 1, 1, 1,
-			 am->fa_acl_in_ip6_l2_node_feat_next_node_index,
-			 &acl_in_l2_ip6_node);
-}
-
-vlib_node_registration_t acl_in_l2_ip4_node;
-static uword
-acl_in_ip4_l2_node_fn (vlib_main_t * vm,
-		       vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  acl_main_t *am = &acl_main;
-  return acl_fa_node_fn (vm, node, frame, 0, 1, 1,
-			 am->fa_acl_in_ip4_l2_node_feat_next_node_index,
-			 &acl_in_l2_ip4_node);
-}
-
-vlib_node_registration_t acl_out_l2_ip6_node;
-static uword
-acl_out_ip6_l2_node_fn (vlib_main_t * vm,
-			vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  acl_main_t *am = &acl_main;
-  return acl_fa_node_fn (vm, node, frame, 1, 0, 1,
-			 am->fa_acl_out_ip6_l2_node_feat_next_node_index,
-			 &acl_out_l2_ip6_node);
-}
-
-vlib_node_registration_t acl_out_l2_ip4_node;
-static uword
-acl_out_ip4_l2_node_fn (vlib_main_t * vm,
-			vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  acl_main_t *am = &acl_main;
-  return acl_fa_node_fn (vm, node, frame, 0, 0, 1,
-			 am->fa_acl_out_ip4_l2_node_feat_next_node_index,
-			 &acl_out_l2_ip4_node);
-}
-
-
-/**** L3 processing path nodes ****/
-
-
-vlib_node_registration_t acl_in_fa_ip6_node;
-static uword
-acl_in_ip6_fa_node_fn (vlib_main_t * vm,
-		       vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return acl_fa_node_fn (vm, node, frame, 1, 1, 0, 0, &acl_in_fa_ip6_node);
-}
-
-vlib_node_registration_t acl_in_fa_ip4_node;
-static uword
-acl_in_ip4_fa_node_fn (vlib_main_t * vm,
-		       vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return acl_fa_node_fn (vm, node, frame, 0, 1, 0, 0, &acl_in_fa_ip4_node);
-}
-
-vlib_node_registration_t acl_out_fa_ip6_node;
-static uword
-acl_out_ip6_fa_node_fn (vlib_main_t * vm,
-			vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return acl_fa_node_fn (vm, node, frame, 1, 0, 0, 0, &acl_out_fa_ip6_node);
-}
-
-vlib_node_registration_t acl_out_fa_ip4_node;
-static uword
-acl_out_ip4_fa_node_fn (vlib_main_t * vm,
-			vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return acl_fa_node_fn (vm, node, frame, 0, 0, 0, 0, &acl_out_fa_ip4_node);
-}
-
-/*
- * This process ensures the connection cleanup happens every so often
- * even in absence of traffic, as well as provides general orchestration
- * for requests like connection deletion on a given sw_if_index.
- */
-
-
-/* *INDENT-OFF* */
-#define foreach_acl_fa_cleaner_error \
-_(UNKNOWN_EVENT, "unknown event received")  \
-/* end  of errors */
-
-typedef enum
-{
-#define _(sym,str) ACL_FA_CLEANER_ERROR_##sym,
-  foreach_acl_fa_cleaner_error
-#undef _
-    ACL_FA_CLEANER_N_ERROR,
-} acl_fa_cleaner_error_t;
-
-static char *acl_fa_cleaner_error_strings[] = {
-#define _(sym,string) string,
-  foreach_acl_fa_cleaner_error
-#undef _
-};
-
-/* *INDENT-ON* */
-
-static vlib_node_registration_t acl_fa_session_cleaner_process_node;
-static vlib_node_registration_t acl_fa_worker_session_cleaner_process_node;
-
-/*
- * Per-worker thread interrupt-driven cleaner thread
- * to clean idle connections if there are no packets
- */
-static uword
-acl_fa_worker_conn_cleaner_process(vlib_main_t * vm,
-              vlib_node_runtime_t * rt, vlib_frame_t * f)
-{
-   acl_main_t *am = &acl_main;
-   u64 now = clib_cpu_time_now ();
-   u16 thread_index = os_get_thread_index ();
-   acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-   int num_expired;
-   elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner interrupt: now %lu", "i8", now);
-   /* allow another interrupt to be queued */
-   pw->interrupt_is_pending = 0;
-   if (pw->clear_in_process) {
-     if (0 == pw->swipe_end_time) {
-       /*
-        * Someone has just set the flag to start clearing.
-        * we do this by combing through the connections up to a "time T"
-        * which is now, and requeueing everything except the expired
-        * connections and those matching the interface(s) being cleared.
-        */
-
-       /*
-        * first filter the sw_if_index bitmap that they want from us, by
-        * a bitmap of sw_if_index for which we actually have connections.
-        */
-       if ((pw->pending_clear_sw_if_index_bitmap == 0)
-           || (pw->serviced_sw_if_index_bitmap == 0)) {
-         elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner: now %lu, someone tried to call clear but one of the bitmaps are empty", "i8", now);
-	 clib_bitmap_zero(pw->pending_clear_sw_if_index_bitmap);
-       } else {
-#ifdef FA_NODE_VERBOSE_DEBUG
-         clib_warning("WORKER-CLEAR: (before and) swiping sw-if-index bitmap: %U, my serviced bitmap %U",
-                      format_bitmap_hex, pw->pending_clear_sw_if_index_bitmap,
-                      format_bitmap_hex, pw->serviced_sw_if_index_bitmap);
-#endif
-         pw->pending_clear_sw_if_index_bitmap = clib_bitmap_and(pw->pending_clear_sw_if_index_bitmap,
-							      pw->serviced_sw_if_index_bitmap);
-       }
-
-       if (clib_bitmap_is_zero(pw->pending_clear_sw_if_index_bitmap)) {
-         /* if the cross-section is a zero vector, no need to do anything. */
-         elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner: now %lu, clearing done, nothing to do", "i8", now);
-         pw->clear_in_process = 0;
-       } else {
-#ifdef FA_NODE_VERBOSE_DEBUG
-         clib_warning("WORKER-CLEAR: swiping sw-if-index bitmap: %U, my serviced bitmap %U",
-                      format_bitmap_hex, pw->pending_clear_sw_if_index_bitmap,
-                      format_bitmap_hex, pw->serviced_sw_if_index_bitmap);
-#endif
-         elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner: swiping until %lu", "i8", now);
-         /* swipe through the connection lists until enqueue timestamps become above "now" */
-         pw->swipe_end_time = now;
-       }
-     }
-   }
-   num_expired = acl_fa_check_idle_sessions(am, thread_index, now);
-   // clib_warning("WORKER-CLEAR: checked %d sessions (clear_in_progress: %d)", num_expired, pw->clear_in_process);
-   elog_acl_maybe_trace_X2(am, "acl_fa_worker_conn_cleaner: checked %d sessions (clear_in_process: %d)", "i4i4", (u32)num_expired, (u32)pw->clear_in_process);
-   if (pw->clear_in_process) {
-     if (0 == num_expired) {
-       /* we were clearing but we could not process any more connections. time to stop. */
-       clib_bitmap_zero(pw->pending_clear_sw_if_index_bitmap);
-       pw->clear_in_process = 0;
-       elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner: now %lu, clearing done - all done", "i8", now);
-     } else {
-       elog_acl_maybe_trace_X1(am, "acl_fa_worker_conn_cleaner: now %lu, more work to do - requesting interrupt", "i8", now);
-       /* should continue clearing.. So could they please sent an interrupt again? */
-       pw->interrupt_is_needed = 1;
-     }
-   } else {
-     if (num_expired >= am->fa_max_deleted_sessions_per_interval) {
-       /* there was too much work, we should get an interrupt ASAP */
-       pw->interrupt_is_needed = 1;
-       pw->interrupt_is_unwanted = 0;
-     } else if (num_expired <= am->fa_min_deleted_sessions_per_interval) {
-       /* signal that they should trigger us less */
-       pw->interrupt_is_needed = 0;
-       pw->interrupt_is_unwanted = 1;
-     } else {
-       /* the current rate of interrupts is ok */
-       pw->interrupt_is_needed = 0;
-       pw->interrupt_is_unwanted = 0;
-     }
-     elog_acl_maybe_trace_X3(am, "acl_fa_worker_conn_cleaner: now %lu, interrupt needed: %u, interrupt unwanted: %u", "i8i4i4", now, ((u32)pw->interrupt_is_needed), ((u32)pw->interrupt_is_unwanted));
-   }
-   pw->interrupt_generation = am->fa_interrupt_generation;
-   return 0;
-}
-
-static void
-send_one_worker_interrupt (vlib_main_t * vm, acl_main_t *am, int thread_index)
-{
-  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
-  if (!pw->interrupt_is_pending) {
-    pw->interrupt_is_pending = 1;
-    vlib_node_set_interrupt_pending (vlib_mains[thread_index],
-                  acl_fa_worker_session_cleaner_process_node.index);
-    elog_acl_maybe_trace_X1(am, "send_one_worker_interrupt: send interrupt to worker %d", "i4", ((u32)thread_index));
-    /* if the interrupt was requested, mark that done. */
-    /* pw->interrupt_is_needed = 0; */
-  }
-}
-
-static void
-send_interrupts_to_workers (vlib_main_t * vm, acl_main_t *am)
-{
-  int i;
-  /* Can't use vec_len(am->per_worker_data) since the threads might not have come up yet; */
-  int n_threads = vec_len(vlib_mains);
-  for (i = 0; i < n_threads; i++) {
-    send_one_worker_interrupt(vm, am, i);
-  }
-}
-
-/* centralized process to drive per-worker cleaners */
-static uword
-acl_fa_session_cleaner_process (vlib_main_t * vm, vlib_node_runtime_t * rt,
-				vlib_frame_t * f)
-{
-  acl_main_t *am = &acl_main;
-  u64 now;
-  f64 cpu_cps = vm->clib_time.clocks_per_second;
-  u64 next_expire;
-  /* We should check if there are connections to clean up - at least twice a second */
-  u64 max_timer_wait_interval = cpu_cps / 2;
-  uword event_type, *event_data = 0;
-  acl_fa_per_worker_data_t *pw0;
-
-  am->fa_current_cleaner_timer_wait_interval = max_timer_wait_interval;
-  am->fa_cleaner_node_index = acl_fa_session_cleaner_process_node.index;
-  am->fa_interrupt_generation = 1;
-  while (1)
-    {
-      now = clib_cpu_time_now ();
-      next_expire = now + am->fa_current_cleaner_timer_wait_interval;
-      int has_pending_conns = 0;
-      u16 ti;
-      u8 tt;
-
-      /*
-       * walk over all per-thread list heads of different timeouts,
-       * and see if there are any connections pending.
-       * If there aren't - we do not need to wake up until the
-       * worker code signals that it has added a connection.
-       *
-       * Also, while we are at it, calculate the earliest we need to wake up.
-       */
-      for(ti = 0; ti < vec_len(vlib_mains); ti++) {
-        if (ti >= vec_len(am->per_worker_data)) {
-          continue;
-        }
-        acl_fa_per_worker_data_t *pw = &am->per_worker_data[ti];
-        for(tt = 0; tt < vec_len(pw->fa_conn_list_head); tt++) {
-          u64 head_expiry = acl_fa_get_list_head_expiry_time(am, pw, now, ti, tt);
-          if ((head_expiry < next_expire) && !pw->interrupt_is_pending) {
-            elog_acl_maybe_trace_X3(am, "acl_fa_session_cleaner_process: now %lu, worker: %d tt: %d", "i8i2i2", now, ti, tt);
-            elog_acl_maybe_trace_X2(am, "acl_fa_session_cleaner_process: head expiry: %lu, is earlier than curr next expire: %lu", "i8i8", head_expiry, next_expire);
-            next_expire = head_expiry;
-	  }
-          if (~0 != pw->fa_conn_list_head[tt]) {
-            has_pending_conns = 1;
-          }
-        }
-      }
-
-      /* If no pending connections and no ACL applied then no point in timing out */
-      if (!has_pending_conns && (0 == am->fa_total_enabled_count))
-        {
-          am->fa_cleaner_cnt_wait_without_timeout++;
-          elog_acl_maybe_trace_X1(am, "acl_conn_cleaner: now %lu entering wait without timeout", "i8", now);
-          (void) vlib_process_wait_for_event (vm);
-          event_type = vlib_process_get_events (vm, &event_data);
-        }
-      else
-	{
-	  f64 timeout = ((i64) next_expire - (i64) now) / cpu_cps;
-	  if (timeout <= 0)
-	    {
-	      /* skip waiting altogether */
-	      event_type = ~0;
-	    }
-	  else
-	    {
-              am->fa_cleaner_cnt_wait_with_timeout++;
-              elog_acl_maybe_trace_X2(am, "acl_conn_cleaner: now %lu entering wait with timeout %.6f sec", "i8f8", now, timeout);
-	      (void) vlib_process_wait_for_event_or_clock (vm, timeout);
-	      event_type = vlib_process_get_events (vm, &event_data);
-	    }
-	}
-
-      switch (event_type)
-	{
-	case ~0:
-	  /* nothing to do */
-	  break;
-	case ACL_FA_CLEANER_RESCHEDULE:
-	  /* Nothing to do. */
-	  break;
-	case ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX:
-	  {
-            uword *clear_sw_if_index_bitmap = 0;
-	    uword *sw_if_index0;
-            int clear_all = 0;
-            now = clib_cpu_time_now ();
-            elog_acl_maybe_trace_X1(am, "acl_fa_session_cleaner_process: now %lu, received ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX", "i8", now);
-	    vec_foreach (sw_if_index0, event_data)
-	    {
-              am->fa_cleaner_cnt_delete_by_sw_index++;
-              elog_acl_maybe_trace_X1(am, "acl_fa_session_cleaner_process: ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX %d", "i4", *sw_if_index0);
-              if (*sw_if_index0 == ~0)
-                {
-                  clear_all = 1;
-                }
-              else
-                {
-                  if (!pool_is_free_index (am->vnet_main->interface_main.sw_interfaces, *sw_if_index0))
-                    {
-                      clear_sw_if_index_bitmap = clib_bitmap_set(clear_sw_if_index_bitmap, *sw_if_index0, 1);
-                    }
-                }
-	    }
-#ifdef FA_NODE_VERBOSE_DEBUG
-	    clib_warning("ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX bitmap: %U", format_bitmap_hex, clear_sw_if_index_bitmap);
-#endif
-	    vec_foreach(pw0, am->per_worker_data) {
-              CLIB_MEMORY_BARRIER ();
-	      while (pw0->clear_in_process) {
-                CLIB_MEMORY_BARRIER ();
-                elog_acl_maybe_trace_X1(am, "ACL_FA_NODE_CLEAN: waiting previous cleaning cycle to finish on %d", "i4", (u32)(pw0 - am->per_worker_data));
-                vlib_process_suspend(vm, 0.0001);
-                if (pw0->interrupt_is_needed) {
-                  send_one_worker_interrupt(vm, am, (pw0 - am->per_worker_data));
-                }
-              }
-              if (pw0->clear_in_process) {
-                clib_warning("ERROR-BUG! Could not initiate cleaning on worker because another cleanup in progress");
-	      } else {
-                if (clear_all)
-                  {
-                    /* if we need to clear all, then just clear the interfaces that we are servicing */
-                    pw0->pending_clear_sw_if_index_bitmap = clib_bitmap_dup(pw0->serviced_sw_if_index_bitmap);
-                  }
-                else
-                  {
-                    pw0->pending_clear_sw_if_index_bitmap = clib_bitmap_dup(clear_sw_if_index_bitmap);
-                  }
-                pw0->clear_in_process = 1;
-              }
-            }
-            /* send some interrupts so they can start working */
-            send_interrupts_to_workers(vm, am);
-
-            /* now wait till they all complete */
-#ifdef FA_NODE_VERBOSE_DEBUG
-	    clib_warning("CLEANER mains len: %d per-worker len: %d", vec_len(vlib_mains), vec_len(am->per_worker_data));
-#endif
-	    vec_foreach(pw0, am->per_worker_data) {
-              CLIB_MEMORY_BARRIER ();
-	      while (pw0->clear_in_process) {
-                CLIB_MEMORY_BARRIER ();
-                elog_acl_maybe_trace_X1(am, "ACL_FA_NODE_CLEAN: waiting for my cleaning cycle to finish on %d", "i4", (u32)(pw0 - am->per_worker_data));
-                vlib_process_suspend(vm, 0.0001);
-                if (pw0->interrupt_is_needed) {
-                  send_one_worker_interrupt(vm, am, (pw0 - am->per_worker_data));
-                }
-              }
-            }
-#ifdef FA_NODE_VERBOSE_DEBUG
-            clib_warning("ACL_FA_NODE_CLEAN: cleaning done");
-#endif
-            clib_bitmap_free(clear_sw_if_index_bitmap);
-	  }
-	  break;
-	default:
-#ifdef FA_NODE_VERBOSE_DEBUG
-	  clib_warning ("ACL plugin connection cleaner: unknown event %u",
-			event_type);
-#endif
-          vlib_node_increment_counter (vm,
-                                       acl_fa_session_cleaner_process_node.
-                                       index,
-                                       ACL_FA_CLEANER_ERROR_UNKNOWN_EVENT, 1);
-          am->fa_cleaner_cnt_unknown_event++;
-	  break;
-	}
-
-      send_interrupts_to_workers(vm, am);
-
-      if (event_data)
-	_vec_len (event_data) = 0;
-
-      /*
-       * If the interrupts were not processed yet, ensure we wait a bit,
-       * but up to a point.
-       */
-      int need_more_wait = 0;
-      int max_wait_cycles = 100;
-      do {
-        need_more_wait = 0;
-        vec_foreach(pw0, am->per_worker_data) {
-          if (pw0->interrupt_generation != am->fa_interrupt_generation) {
-            need_more_wait = 1;
-          }
-        }
-        if (need_more_wait) {
-          vlib_process_suspend(vm, 0.0001);
-        }
-      } while (need_more_wait && (--max_wait_cycles > 0));
-
-      int interrupts_needed = 0;
-      int interrupts_unwanted = 0;
-
-      vec_foreach(pw0, am->per_worker_data) {
-        if (pw0->interrupt_is_needed) {
-          interrupts_needed++;
-          /* the per-worker value is reset when sending the interrupt */
-        }
-        if (pw0->interrupt_is_unwanted) {
-          interrupts_unwanted++;
-          pw0->interrupt_is_unwanted = 0;
-        }
-      }
-      if (interrupts_needed) {
-        /* they need more interrupts, do less waiting around next time */
-        am->fa_current_cleaner_timer_wait_interval /= 2;
-        /* never go into zero-wait either though - we need to give the space to others */
-        am->fa_current_cleaner_timer_wait_interval += 1; 
-      } else if (interrupts_unwanted) {
-        /* slowly increase the amount of sleep up to a limit */
-        if (am->fa_current_cleaner_timer_wait_interval < max_timer_wait_interval)
-          am->fa_current_cleaner_timer_wait_interval += cpu_cps * am->fa_cleaner_wait_time_increment;
-      }
-      am->fa_cleaner_cnt_event_cycles++;
-      am->fa_interrupt_generation++;
-    }
-  /* NOT REACHED */
-  return 0;
-}
-
-
-void
-acl_fa_enable_disable (u32 sw_if_index, int is_input, int enable_disable)
-{
-  acl_main_t *am = &acl_main;
-  if (enable_disable) {
-    acl_fa_verify_init_sessions(am);
-    am->fa_total_enabled_count++;
-    void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
-    vlib_process_signal_event (am->vlib_main, am->fa_cleaner_node_index,
-                                 ACL_FA_CLEANER_RESCHEDULE, 0);
-    clib_mem_set_heap (oldheap);
-  } else {
-    am->fa_total_enabled_count--;
-  }
-
-  if (is_input)
-    {
-      ASSERT(clib_bitmap_get(am->fa_in_acl_on_sw_if_index, sw_if_index) != enable_disable);
-      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
-      vnet_feature_enable_disable ("ip4-unicast", "acl-plugin-in-ip4-fa",
-				   sw_if_index, enable_disable, 0, 0);
-      vnet_feature_enable_disable ("ip6-unicast", "acl-plugin-in-ip6-fa",
-				   sw_if_index, enable_disable, 0, 0);
-      clib_mem_set_heap (oldheap);
-      am->fa_in_acl_on_sw_if_index =
-	clib_bitmap_set (am->fa_in_acl_on_sw_if_index, sw_if_index,
-			 enable_disable);
-    }
-  else
-    {
-      ASSERT(clib_bitmap_get(am->fa_out_acl_on_sw_if_index, sw_if_index) != enable_disable);
-      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
-      vnet_feature_enable_disable ("ip4-output", "acl-plugin-out-ip4-fa",
-				   sw_if_index, enable_disable, 0, 0);
-      vnet_feature_enable_disable ("ip6-output", "acl-plugin-out-ip6-fa",
-				   sw_if_index, enable_disable, 0, 0);
-      clib_mem_set_heap (oldheap);
-      am->fa_out_acl_on_sw_if_index =
-	clib_bitmap_set (am->fa_out_acl_on_sw_if_index, sw_if_index,
-			 enable_disable);
-    }
-  if ((!enable_disable) && (!acl_fa_ifc_has_in_acl (am, sw_if_index))
-      && (!acl_fa_ifc_has_out_acl (am, sw_if_index)))
-    {
-#ifdef FA_NODE_VERBOSE_DEBUG
-      clib_warning("ENABLE-DISABLE: clean the connections on interface %d", sw_if_index);
-#endif
-      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
-      vlib_process_signal_event (am->vlib_main, am->fa_cleaner_node_index,
-				 ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX,
-				 sw_if_index);
-      clib_mem_set_heap (oldheap);
-    }
-}
-
-void
-show_fa_sessions_hash(vlib_main_t * vm, u32 verbose)
-{
-  acl_main_t *am = &acl_main;
-  if (am->fa_sessions_hash_is_initialized) {
-    vlib_cli_output(vm, "\nSession lookup hash table:\n%U\n\n",
-                  BV (format_bihash), &am->fa_sessions_hash, verbose);
-  } else {
-    vlib_cli_output(vm, "\nSession lookup hash table is not allocated.\n\n");
-  }
-}
-
-
-/* *INDENT-OFF* */
-
-VLIB_REGISTER_NODE (acl_fa_worker_session_cleaner_process_node, static) = {
-  .function = acl_fa_worker_conn_cleaner_process,
-  .name = "acl-plugin-fa-worker-cleaner-process",
-  .type = VLIB_NODE_TYPE_INPUT,
-  .state = VLIB_NODE_STATE_INTERRUPT,
-};
-
-VLIB_REGISTER_NODE (acl_fa_session_cleaner_process_node, static) = {
-  .function = acl_fa_session_cleaner_process,
-  .type = VLIB_NODE_TYPE_PROCESS,
-  .name = "acl-plugin-fa-cleaner-process",
-  .n_errors = ARRAY_LEN (acl_fa_cleaner_error_strings),
-  .error_strings = acl_fa_cleaner_error_strings,
-  .n_next_nodes = 0,
-  .next_nodes = {},
-};
-
-
-VLIB_REGISTER_NODE (acl_in_l2_ip6_node) =
-{
-  .function = acl_in_ip6_l2_node_fn,
-  .name = "acl-plugin-in-ip6-l2",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VLIB_REGISTER_NODE (acl_in_l2_ip4_node) =
-{
-  .function = acl_in_ip4_l2_node_fn,
-  .name = "acl-plugin-in-ip4-l2",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VLIB_REGISTER_NODE (acl_out_l2_ip6_node) =
-{
-  .function = acl_out_ip6_l2_node_fn,
-  .name = "acl-plugin-out-ip6-l2",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VLIB_REGISTER_NODE (acl_out_l2_ip4_node) =
-{
-  .function = acl_out_ip4_l2_node_fn,
-  .name = "acl-plugin-out-ip4-l2",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-
-VLIB_REGISTER_NODE (acl_in_fa_ip6_node) =
-{
-  .function = acl_in_ip6_fa_node_fn,
-  .name = "acl-plugin-in-ip6-fa",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VNET_FEATURE_INIT (acl_in_ip6_fa_feature, static) =
-{
-  .arc_name = "ip6-unicast",
-  .node_name = "acl-plugin-in-ip6-fa",
-  .runs_before = VNET_FEATURES ("ip6-flow-classify"),
-};
-
-VLIB_REGISTER_NODE (acl_in_fa_ip4_node) =
-{
-  .function = acl_in_ip4_fa_node_fn,
-  .name = "acl-plugin-in-ip4-fa",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VNET_FEATURE_INIT (acl_in_ip4_fa_feature, static) =
-{
-  .arc_name = "ip4-unicast",
-  .node_name = "acl-plugin-in-ip4-fa",
-  .runs_before = VNET_FEATURES ("ip4-flow-classify"),
-};
-
-
-VLIB_REGISTER_NODE (acl_out_fa_ip6_node) =
-{
-  .function = acl_out_ip6_fa_node_fn,
-  .name = "acl-plugin-out-ip6-fa",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VNET_FEATURE_INIT (acl_out_ip6_fa_feature, static) =
-{
-  .arc_name = "ip6-output",
-  .node_name = "acl-plugin-out-ip6-fa",
-  .runs_before = VNET_FEATURES ("interface-output"),
-};
-
-VLIB_REGISTER_NODE (acl_out_fa_ip4_node) =
-{
-  .function = acl_out_ip4_fa_node_fn,
-  .name = "acl-plugin-out-ip4-fa",
-  .vector_size = sizeof (u32),
-  .format_trace = format_acl_fa_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (acl_fa_error_strings),
-  .error_strings = acl_fa_error_strings,
-  .n_next_nodes = ACL_FA_N_NEXT,
-    /* edit / add dispositions here */
-  .next_nodes =
-  {
-    [ACL_FA_ERROR_DROP] = "error-drop",
-  }
-};
-
-VNET_FEATURE_INIT (acl_out_ip4_fa_feature, static) =
-{
-  .arc_name = "ip4-output",
-  .node_name = "acl-plugin-out-ip4-fa",
-  .runs_before = VNET_FEATURES ("interface-output"),
-};
-
-
-/* *INDENT-ON* */
diff --git a/src/plugins/acl/sess_mgmt_node.c b/src/plugins/acl/sess_mgmt_node.c
new file mode 100644
index 00000000000..b4faf554612
--- /dev/null
+++ b/src/plugins/acl/sess_mgmt_node.c
@@ -0,0 +1,806 @@
+/*
+ * Copyright (c) 2016-2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stddef.h>
+#include <netinet/in.h>
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+
+
+#include <acl/acl.h>
+#include <vnet/ip/icmp46_packet.h>
+
+#include <plugins/acl/fa_node.h>
+#include <plugins/acl/acl.h>
+#include <plugins/acl/lookup_context.h>
+#include <plugins/acl/public_inlines.h>
+#include <plugins/acl/session_inlines.h>
+
+// #include <vppinfra/bihash_40_8.h>
+
+
+static u64
+fa_session_get_shortest_timeout (acl_main_t * am)
+{
+  int timeout_type;
+  u64 timeout = ~0LL;
+  for (timeout_type = 0; timeout_type < ACL_N_TIMEOUTS; timeout_type++)
+    {
+      if (timeout > am->session_timeout_sec[timeout_type])
+	{
+	  timeout = am->session_timeout_sec[timeout_type];
+	}
+    }
+  return timeout;
+}
+
+static void
+acl_fa_verify_init_sessions (acl_main_t * am)
+{
+  if (!am->fa_sessions_hash_is_initialized)
+    {
+      u16 wk;
+      /* Allocate the per-worker sessions pools */
+      for (wk = 0; wk < vec_len (am->per_worker_data); wk++)
+	{
+	  acl_fa_per_worker_data_t *pw = &am->per_worker_data[wk];
+
+	  /*
+	   * // In lieu of trying to preallocate the pool and its free bitmap, rather use pool_init_fixed
+	   * pool_alloc_aligned(pw->fa_sessions_pool, am->fa_conn_table_max_entries, CLIB_CACHE_LINE_BYTES);
+	   * clib_bitmap_validate(pool_header(pw->fa_sessions_pool)->free_bitmap, am->fa_conn_table_max_entries);
+	   */
+	  pool_init_fixed (pw->fa_sessions_pool,
+			   am->fa_conn_table_max_entries);
+	}
+
+      /* ... and the interface session hash table */
+      clib_bihash_init_40_8 (&am->fa_sessions_hash,
+			     "ACL plugin FA session bihash",
+			     am->fa_conn_table_hash_num_buckets,
+			     am->fa_conn_table_hash_memory_size);
+      am->fa_sessions_hash_is_initialized = 1;
+    }
+}
+
+
+/*
+ * Get the timeout of the session in a list since its enqueue time.
+ */
+
+static u64
+fa_session_get_list_timeout (acl_main_t * am, fa_session_t * sess)
+{
+  u64 timeout = am->vlib_main->clib_time.clocks_per_second;
+  /*
+   * we have the shortest possible timeout type in all the lists
+   * (see README-multicore for the rationale)
+   */
+  timeout *= fa_session_get_shortest_timeout (am);
+  return timeout;
+}
+
+static u64
+acl_fa_get_list_head_expiry_time (acl_main_t * am,
+				  acl_fa_per_worker_data_t * pw, u64 now,
+				  u16 thread_index, int timeout_type)
+{
+  fa_session_t *sess =
+    get_session_ptr (am, thread_index, pw->fa_conn_list_head[timeout_type]);
+  /*
+   * We can not check just the index here because inbetween the worker thread might
+   * dequeue the connection from the head just as we are about to check it.
+   */
+  if (!is_valid_session_ptr (am, thread_index, sess))
+    {
+      return ~0LL;		// infinity.
+    }
+  else
+    {
+      u64 timeout_time =
+	sess->link_enqueue_time + fa_session_get_list_timeout (am, sess);
+      return timeout_time;
+    }
+}
+
+static int
+acl_fa_conn_time_to_check (acl_main_t * am, acl_fa_per_worker_data_t * pw,
+			   u64 now, u16 thread_index, u32 session_index)
+{
+  fa_session_t *sess = get_session_ptr (am, thread_index, session_index);
+  u64 timeout_time =
+    sess->link_enqueue_time + fa_session_get_list_timeout (am, sess);
+  return (timeout_time < now)
+    || (sess->link_enqueue_time <= pw->swipe_end_time);
+}
+
+/*
+ * see if there are sessions ready to be checked,
+ * do the maintenance (requeue or delete), and
+ * return the total number of sessions reclaimed.
+ */
+static int
+acl_fa_check_idle_sessions (acl_main_t * am, u16 thread_index, u64 now)
+{
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  fa_full_session_id_t fsid;
+  fsid.thread_index = thread_index;
+  int total_expired = 0;
+
+  {
+    u8 tt = 0;
+    for (tt = 0; tt < ACL_N_TIMEOUTS; tt++)
+      {
+	while ((vec_len (pw->expired) <
+		am->fa_max_deleted_sessions_per_interval)
+	       && (~0 != pw->fa_conn_list_head[tt])
+	       &&
+	       (acl_fa_conn_time_to_check
+		(am, pw, now, thread_index, pw->fa_conn_list_head[tt])))
+	  {
+	    fsid.session_index = pw->fa_conn_list_head[tt];
+	    elog_acl_maybe_trace_X2 (am,
+				     "acl_fa_check_idle_sessions: expire session %d on thread %d",
+				     "i4i4", (u32) fsid.session_index,
+				     (u32) thread_index);
+	    vec_add1 (pw->expired, fsid.session_index);
+	    acl_fa_conn_list_delete_session (am, fsid);
+	  }
+      }
+  }
+
+  u32 *psid = NULL;
+  vec_foreach (psid, pw->expired)
+  {
+    fsid.session_index = *psid;
+    if (!pool_is_free_index (pw->fa_sessions_pool, fsid.session_index))
+      {
+	fa_session_t *sess =
+	  get_session_ptr (am, thread_index, fsid.session_index);
+	u32 sw_if_index = sess->sw_if_index;
+	u64 sess_timeout_time =
+	  sess->last_active_time + fa_session_get_timeout (am, sess);
+	if ((now < sess_timeout_time)
+	    && (0 ==
+		clib_bitmap_get (pw->pending_clear_sw_if_index_bitmap,
+				 sw_if_index)))
+	  {
+#ifdef FA_NODE_VERBOSE_DEBUG
+	    clib_warning
+	      ("ACL_FA_NODE_CLEAN: Restarting timer for session %d, sw_if_index %d",
+	       (int) fsid.session_index, sess->sw_if_index);
+#endif
+	    /* There was activity on the session, so the idle timeout
+	       has not passed. Enqueue for another time period. */
+
+	    acl_fa_conn_list_add_session (am, fsid, now);
+	    pw->cnt_session_timer_restarted++;
+	  }
+	else
+	  {
+#ifdef FA_NODE_VERBOSE_DEBUG
+	    clib_warning
+	      ("ACL_FA_NODE_CLEAN: Deleting session %d, sw_if_index %d",
+	       (int) fsid.session_index, sess->sw_if_index);
+#endif
+	    acl_fa_delete_session (am, sw_if_index, fsid);
+	    pw->cnt_deleted_sessions++;
+	  }
+      }
+    else
+      {
+	pw->cnt_already_deleted_sessions++;
+      }
+  }
+  total_expired = vec_len (pw->expired);
+  /* zero out the vector which we have acted on */
+  if (pw->expired)
+    _vec_len (pw->expired) = 0;
+  /* if we were advancing and reached the end
+   * (no more sessions to recycle), reset the fast-forward timestamp */
+
+  if (pw->swipe_end_time && 0 == total_expired)
+    pw->swipe_end_time = 0;
+  return (total_expired);
+}
+
+/*
+ * This process ensures the connection cleanup happens every so often
+ * even in absence of traffic, as well as provides general orchestration
+ * for requests like connection deletion on a given sw_if_index.
+ */
+
+
+/* *INDENT-OFF* */
+#define foreach_acl_fa_cleaner_error \
+_(UNKNOWN_EVENT, "unknown event received")  \
+/* end  of errors */
+
+typedef enum
+{
+#define _(sym,str) ACL_FA_CLEANER_ERROR_##sym,
+  foreach_acl_fa_cleaner_error
+#undef _
+    ACL_FA_CLEANER_N_ERROR,
+} acl_fa_cleaner_error_t;
+
+static char *acl_fa_cleaner_error_strings[] = {
+#define _(sym,string) string,
+  foreach_acl_fa_cleaner_error
+#undef _
+};
+
+/* *INDENT-ON* */
+
+static vlib_node_registration_t acl_fa_session_cleaner_process_node;
+static vlib_node_registration_t acl_fa_worker_session_cleaner_process_node;
+
+/*
+ * Per-worker thread interrupt-driven cleaner thread
+ * to clean idle connections if there are no packets
+ */
+static uword
+acl_fa_worker_conn_cleaner_process (vlib_main_t * vm,
+				    vlib_node_runtime_t * rt,
+				    vlib_frame_t * f)
+{
+  acl_main_t *am = &acl_main;
+  u64 now = clib_cpu_time_now ();
+  u16 thread_index = os_get_thread_index ();
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  int num_expired;
+  elog_acl_maybe_trace_X1 (am,
+			   "acl_fa_worker_conn_cleaner interrupt: now %lu",
+			   "i8", now);
+  /* allow another interrupt to be queued */
+  pw->interrupt_is_pending = 0;
+  if (pw->clear_in_process)
+    {
+      if (0 == pw->swipe_end_time)
+	{
+	  /*
+	   * Someone has just set the flag to start clearing.
+	   * we do this by combing through the connections up to a "time T"
+	   * which is now, and requeueing everything except the expired
+	   * connections and those matching the interface(s) being cleared.
+	   */
+
+	  /*
+	   * first filter the sw_if_index bitmap that they want from us, by
+	   * a bitmap of sw_if_index for which we actually have connections.
+	   */
+	  if ((pw->pending_clear_sw_if_index_bitmap == 0)
+	      || (pw->serviced_sw_if_index_bitmap == 0))
+	    {
+	      elog_acl_maybe_trace_X1 (am,
+				       "acl_fa_worker_conn_cleaner: now %lu, someone tried to call clear but one of the bitmaps are empty",
+				       "i8", now);
+	      clib_bitmap_zero (pw->pending_clear_sw_if_index_bitmap);
+	    }
+	  else
+	    {
+#ifdef FA_NODE_VERBOSE_DEBUG
+	      clib_warning
+		("WORKER-CLEAR: (before and) swiping sw-if-index bitmap: %U, my serviced bitmap %U",
+		 format_bitmap_hex, pw->pending_clear_sw_if_index_bitmap,
+		 format_bitmap_hex, pw->serviced_sw_if_index_bitmap);
+#endif
+	      pw->pending_clear_sw_if_index_bitmap =
+		clib_bitmap_and (pw->pending_clear_sw_if_index_bitmap,
+				 pw->serviced_sw_if_index_bitmap);
+	    }
+
+	  if (clib_bitmap_is_zero (pw->pending_clear_sw_if_index_bitmap))
+	    {
+	      /* if the cross-section is a zero vector, no need to do anything. */
+	      elog_acl_maybe_trace_X1 (am,
+				       "acl_fa_worker_conn_cleaner: now %lu, clearing done, nothing to do",
+				       "i8", now);
+	      pw->clear_in_process = 0;
+	    }
+	  else
+	    {
+#ifdef FA_NODE_VERBOSE_DEBUG
+	      clib_warning
+		("WORKER-CLEAR: swiping sw-if-index bitmap: %U, my serviced bitmap %U",
+		 format_bitmap_hex, pw->pending_clear_sw_if_index_bitmap,
+		 format_bitmap_hex, pw->serviced_sw_if_index_bitmap);
+#endif
+	      elog_acl_maybe_trace_X1 (am,
+				       "acl_fa_worker_conn_cleaner: swiping until %lu",
+				       "i8", now);
+	      /* swipe through the connection lists until enqueue timestamps become above "now" */
+	      pw->swipe_end_time = now;
+	    }
+	}
+    }
+  num_expired = acl_fa_check_idle_sessions (am, thread_index, now);
+  // clib_warning("WORKER-CLEAR: checked %d sessions (clear_in_progress: %d)", num_expired, pw->clear_in_process);
+  elog_acl_maybe_trace_X2 (am,
+			   "acl_fa_worker_conn_cleaner: checked %d sessions (clear_in_process: %d)",
+			   "i4i4", (u32) num_expired,
+			   (u32) pw->clear_in_process);
+  if (pw->clear_in_process)
+    {
+      if (0 == num_expired)
+	{
+	  /* we were clearing but we could not process any more connections. time to stop. */
+	  clib_bitmap_zero (pw->pending_clear_sw_if_index_bitmap);
+	  pw->clear_in_process = 0;
+	  elog_acl_maybe_trace_X1 (am,
+				   "acl_fa_worker_conn_cleaner: now %lu, clearing done - all done",
+				   "i8", now);
+	}
+      else
+	{
+	  elog_acl_maybe_trace_X1 (am,
+				   "acl_fa_worker_conn_cleaner: now %lu, more work to do - requesting interrupt",
+				   "i8", now);
+	  /* should continue clearing.. So could they please sent an interrupt again? */
+	  pw->interrupt_is_needed = 1;
+	}
+    }
+  else
+    {
+      if (num_expired >= am->fa_max_deleted_sessions_per_interval)
+	{
+	  /* there was too much work, we should get an interrupt ASAP */
+	  pw->interrupt_is_needed = 1;
+	  pw->interrupt_is_unwanted = 0;
+	}
+      else if (num_expired <= am->fa_min_deleted_sessions_per_interval)
+	{
+	  /* signal that they should trigger us less */
+	  pw->interrupt_is_needed = 0;
+	  pw->interrupt_is_unwanted = 1;
+	}
+      else
+	{
+	  /* the current rate of interrupts is ok */
+	  pw->interrupt_is_needed = 0;
+	  pw->interrupt_is_unwanted = 0;
+	}
+      elog_acl_maybe_trace_X3 (am,
+			       "acl_fa_worker_conn_cleaner: now %lu, interrupt needed: %u, interrupt unwanted: %u",
+			       "i8i4i4", now, ((u32) pw->interrupt_is_needed),
+			       ((u32) pw->interrupt_is_unwanted));
+    }
+  pw->interrupt_generation = am->fa_interrupt_generation;
+  return 0;
+}
+
+static void
+send_one_worker_interrupt (vlib_main_t * vm, acl_main_t * am,
+			   int thread_index)
+{
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  if (!pw->interrupt_is_pending)
+    {
+      pw->interrupt_is_pending = 1;
+      vlib_node_set_interrupt_pending (vlib_mains[thread_index],
+				       acl_fa_worker_session_cleaner_process_node.index);
+      elog_acl_maybe_trace_X1 (am,
+			       "send_one_worker_interrupt: send interrupt to worker %d",
+			       "i4", ((u32) thread_index));
+      /* if the interrupt was requested, mark that done. */
+      /* pw->interrupt_is_needed = 0; */
+    }
+}
+
+static void
+send_interrupts_to_workers (vlib_main_t * vm, acl_main_t * am)
+{
+  int i;
+  /* Can't use vec_len(am->per_worker_data) since the threads might not have come up yet; */
+  int n_threads = vec_len (vlib_mains);
+  for (i = 0; i < n_threads; i++)
+    {
+      send_one_worker_interrupt (vm, am, i);
+    }
+}
+
+/* centralized process to drive per-worker cleaners */
+static uword
+acl_fa_session_cleaner_process (vlib_main_t * vm, vlib_node_runtime_t * rt,
+				vlib_frame_t * f)
+{
+  acl_main_t *am = &acl_main;
+  u64 now;
+  f64 cpu_cps = vm->clib_time.clocks_per_second;
+  u64 next_expire;
+  /* We should check if there are connections to clean up - at least twice a second */
+  u64 max_timer_wait_interval = cpu_cps / 2;
+  uword event_type, *event_data = 0;
+  acl_fa_per_worker_data_t *pw0;
+
+  am->fa_current_cleaner_timer_wait_interval = max_timer_wait_interval;
+  am->fa_cleaner_node_index = acl_fa_session_cleaner_process_node.index;
+  am->fa_interrupt_generation = 1;
+  while (1)
+    {
+      now = clib_cpu_time_now ();
+      next_expire = now + am->fa_current_cleaner_timer_wait_interval;
+      int has_pending_conns = 0;
+      u16 ti;
+      u8 tt;
+
+      /*
+       * walk over all per-thread list heads of different timeouts,
+       * and see if there are any connections pending.
+       * If there aren't - we do not need to wake up until the
+       * worker code signals that it has added a connection.
+       *
+       * Also, while we are at it, calculate the earliest we need to wake up.
+       */
+      for (ti = 0; ti < vec_len (vlib_mains); ti++)
+	{
+	  if (ti >= vec_len (am->per_worker_data))
+	    {
+	      continue;
+	    }
+	  acl_fa_per_worker_data_t *pw = &am->per_worker_data[ti];
+	  for (tt = 0; tt < vec_len (pw->fa_conn_list_head); tt++)
+	    {
+	      u64 head_expiry =
+		acl_fa_get_list_head_expiry_time (am, pw, now, ti, tt);
+	      if ((head_expiry < next_expire) && !pw->interrupt_is_pending)
+		{
+		  elog_acl_maybe_trace_X3 (am,
+					   "acl_fa_session_cleaner_process: now %lu, worker: %d tt: %d",
+					   "i8i2i2", now, ti, tt);
+		  elog_acl_maybe_trace_X2 (am,
+					   "acl_fa_session_cleaner_process: head expiry: %lu, is earlier than curr next expire: %lu",
+					   "i8i8", head_expiry, next_expire);
+		  next_expire = head_expiry;
+		}
+	      if (~0 != pw->fa_conn_list_head[tt])
+		{
+		  has_pending_conns = 1;
+		}
+	    }
+	}
+
+      /* If no pending connections and no ACL applied then no point in timing out */
+      if (!has_pending_conns && (0 == am->fa_total_enabled_count))
+	{
+	  am->fa_cleaner_cnt_wait_without_timeout++;
+	  elog_acl_maybe_trace_X1 (am,
+				   "acl_conn_cleaner: now %lu entering wait without timeout",
+				   "i8", now);
+	  (void) vlib_process_wait_for_event (vm);
+	  event_type = vlib_process_get_events (vm, &event_data);
+	}
+      else
+	{
+	  f64 timeout = ((i64) next_expire - (i64) now) / cpu_cps;
+	  if (timeout <= 0)
+	    {
+	      /* skip waiting altogether */
+	      event_type = ~0;
+	    }
+	  else
+	    {
+	      am->fa_cleaner_cnt_wait_with_timeout++;
+	      elog_acl_maybe_trace_X2 (am,
+				       "acl_conn_cleaner: now %lu entering wait with timeout %.6f sec",
+				       "i8f8", now, timeout);
+	      (void) vlib_process_wait_for_event_or_clock (vm, timeout);
+	      event_type = vlib_process_get_events (vm, &event_data);
+	    }
+	}
+
+      switch (event_type)
+	{
+	case ~0:
+	  /* nothing to do */
+	  break;
+	case ACL_FA_CLEANER_RESCHEDULE:
+	  /* Nothing to do. */
+	  break;
+	case ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX:
+	  {
+	    uword *clear_sw_if_index_bitmap = 0;
+	    uword *sw_if_index0;
+	    int clear_all = 0;
+	    now = clib_cpu_time_now ();
+	    elog_acl_maybe_trace_X1 (am,
+				     "acl_fa_session_cleaner_process: now %lu, received ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX",
+				     "i8", now);
+	    vec_foreach (sw_if_index0, event_data)
+	    {
+	      am->fa_cleaner_cnt_delete_by_sw_index++;
+	      elog_acl_maybe_trace_X1 (am,
+				       "acl_fa_session_cleaner_process: ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX %d",
+				       "i4", *sw_if_index0);
+	      if (*sw_if_index0 == ~0)
+		{
+		  clear_all = 1;
+		}
+	      else
+		{
+		  if (!pool_is_free_index
+		      (am->vnet_main->interface_main.sw_interfaces,
+		       *sw_if_index0))
+		    {
+		      clear_sw_if_index_bitmap =
+			clib_bitmap_set (clear_sw_if_index_bitmap,
+					 *sw_if_index0, 1);
+		    }
+		}
+	    }
+#ifdef FA_NODE_VERBOSE_DEBUG
+	    clib_warning ("ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX bitmap: %U",
+			  format_bitmap_hex, clear_sw_if_index_bitmap);
+#endif
+	    vec_foreach (pw0, am->per_worker_data)
+	    {
+	      CLIB_MEMORY_BARRIER ();
+	      while (pw0->clear_in_process)
+		{
+		  CLIB_MEMORY_BARRIER ();
+		  elog_acl_maybe_trace_X1 (am,
+					   "ACL_FA_NODE_CLEAN: waiting previous cleaning cycle to finish on %d",
+					   "i4",
+					   (u32) (pw0 - am->per_worker_data));
+		  vlib_process_suspend (vm, 0.0001);
+		  if (pw0->interrupt_is_needed)
+		    {
+		      send_one_worker_interrupt (vm, am,
+						 (pw0 - am->per_worker_data));
+		    }
+		}
+	      if (pw0->clear_in_process)
+		{
+		  clib_warning
+		    ("ERROR-BUG! Could not initiate cleaning on worker because another cleanup in progress");
+		}
+	      else
+		{
+		  if (clear_all)
+		    {
+		      /* if we need to clear all, then just clear the interfaces that we are servicing */
+		      pw0->pending_clear_sw_if_index_bitmap =
+			clib_bitmap_dup (pw0->serviced_sw_if_index_bitmap);
+		    }
+		  else
+		    {
+		      pw0->pending_clear_sw_if_index_bitmap =
+			clib_bitmap_dup (clear_sw_if_index_bitmap);
+		    }
+		  pw0->clear_in_process = 1;
+		}
+	    }
+	    /* send some interrupts so they can start working */
+	    send_interrupts_to_workers (vm, am);
+
+	    /* now wait till they all complete */
+#ifdef FA_NODE_VERBOSE_DEBUG
+	    clib_warning ("CLEANER mains len: %d per-worker len: %d",
+			  vec_len (vlib_mains),
+			  vec_len (am->per_worker_data));
+#endif
+	    vec_foreach (pw0, am->per_worker_data)
+	    {
+	      CLIB_MEMORY_BARRIER ();
+	      while (pw0->clear_in_process)
+		{
+		  CLIB_MEMORY_BARRIER ();
+		  elog_acl_maybe_trace_X1 (am,
+					   "ACL_FA_NODE_CLEAN: waiting for my cleaning cycle to finish on %d",
+					   "i4",
+					   (u32) (pw0 - am->per_worker_data));
+		  vlib_process_suspend (vm, 0.0001);
+		  if (pw0->interrupt_is_needed)
+		    {
+		      send_one_worker_interrupt (vm, am,
+						 (pw0 - am->per_worker_data));
+		    }
+		}
+	    }
+#ifdef FA_NODE_VERBOSE_DEBUG
+	    clib_warning ("ACL_FA_NODE_CLEAN: cleaning done");
+#endif
+	    clib_bitmap_free (clear_sw_if_index_bitmap);
+	  }
+	  break;
+	default:
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning ("ACL plugin connection cleaner: unknown event %u",
+			event_type);
+#endif
+	  vlib_node_increment_counter (vm,
+				       acl_fa_session_cleaner_process_node.
+				       index,
+				       ACL_FA_CLEANER_ERROR_UNKNOWN_EVENT, 1);
+	  am->fa_cleaner_cnt_unknown_event++;
+	  break;
+	}
+
+      send_interrupts_to_workers (vm, am);
+
+      if (event_data)
+	_vec_len (event_data) = 0;
+
+      /*
+       * If the interrupts were not processed yet, ensure we wait a bit,
+       * but up to a point.
+       */
+      int need_more_wait = 0;
+      int max_wait_cycles = 100;
+      do
+	{
+	  need_more_wait = 0;
+	  vec_foreach (pw0, am->per_worker_data)
+	  {
+	    if (pw0->interrupt_generation != am->fa_interrupt_generation)
+	      {
+		need_more_wait = 1;
+	      }
+	  }
+	  if (need_more_wait)
+	    {
+	      vlib_process_suspend (vm, 0.0001);
+	    }
+	}
+      while (need_more_wait && (--max_wait_cycles > 0));
+
+      int interrupts_needed = 0;
+      int interrupts_unwanted = 0;
+
+      vec_foreach (pw0, am->per_worker_data)
+      {
+	if (pw0->interrupt_is_needed)
+	  {
+	    interrupts_needed++;
+	    /* the per-worker value is reset when sending the interrupt */
+	  }
+	if (pw0->interrupt_is_unwanted)
+	  {
+	    interrupts_unwanted++;
+	    pw0->interrupt_is_unwanted = 0;
+	  }
+      }
+      if (interrupts_needed)
+	{
+	  /* they need more interrupts, do less waiting around next time */
+	  am->fa_current_cleaner_timer_wait_interval /= 2;
+	  /* never go into zero-wait either though - we need to give the space to others */
+	  am->fa_current_cleaner_timer_wait_interval += 1;
+	}
+      else if (interrupts_unwanted)
+	{
+	  /* slowly increase the amount of sleep up to a limit */
+	  if (am->fa_current_cleaner_timer_wait_interval <
+	      max_timer_wait_interval)
+	    am->fa_current_cleaner_timer_wait_interval +=
+	      cpu_cps * am->fa_cleaner_wait_time_increment;
+	}
+      am->fa_cleaner_cnt_event_cycles++;
+      am->fa_interrupt_generation++;
+    }
+  /* NOT REACHED */
+  return 0;
+}
+
+
+void
+acl_fa_enable_disable (u32 sw_if_index, int is_input, int enable_disable)
+{
+  acl_main_t *am = &acl_main;
+  if (enable_disable)
+    {
+      acl_fa_verify_init_sessions (am);
+      am->fa_total_enabled_count++;
+      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
+      vlib_process_signal_event (am->vlib_main, am->fa_cleaner_node_index,
+				 ACL_FA_CLEANER_RESCHEDULE, 0);
+      clib_mem_set_heap (oldheap);
+    }
+  else
+    {
+      am->fa_total_enabled_count--;
+    }
+
+  if (is_input)
+    {
+      ASSERT (clib_bitmap_get (am->fa_in_acl_on_sw_if_index, sw_if_index) !=
+	      enable_disable);
+      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
+      vnet_feature_enable_disable ("ip4-unicast", "acl-plugin-in-ip4-fa",
+				   sw_if_index, enable_disable, 0, 0);
+      vnet_feature_enable_disable ("ip6-unicast", "acl-plugin-in-ip6-fa",
+				   sw_if_index, enable_disable, 0, 0);
+      clib_mem_set_heap (oldheap);
+      am->fa_in_acl_on_sw_if_index =
+	clib_bitmap_set (am->fa_in_acl_on_sw_if_index, sw_if_index,
+			 enable_disable);
+    }
+  else
+    {
+      ASSERT (clib_bitmap_get (am->fa_out_acl_on_sw_if_index, sw_if_index) !=
+	      enable_disable);
+      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
+      vnet_feature_enable_disable ("ip4-output", "acl-plugin-out-ip4-fa",
+				   sw_if_index, enable_disable, 0, 0);
+      vnet_feature_enable_disable ("ip6-output", "acl-plugin-out-ip6-fa",
+				   sw_if_index, enable_disable, 0, 0);
+      clib_mem_set_heap (oldheap);
+      am->fa_out_acl_on_sw_if_index =
+	clib_bitmap_set (am->fa_out_acl_on_sw_if_index, sw_if_index,
+			 enable_disable);
+    }
+  if ((!enable_disable) && (!acl_fa_ifc_has_in_acl (am, sw_if_index))
+      && (!acl_fa_ifc_has_out_acl (am, sw_if_index)))
+    {
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning ("ENABLE-DISABLE: clean the connections on interface %d",
+		    sw_if_index);
+#endif
+      void *oldheap = clib_mem_set_heap (am->vlib_main->heap_base);
+      vlib_process_signal_event (am->vlib_main, am->fa_cleaner_node_index,
+				 ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX,
+				 sw_if_index);
+      clib_mem_set_heap (oldheap);
+    }
+}
+
+void
+show_fa_sessions_hash (vlib_main_t * vm, u32 verbose)
+{
+  acl_main_t *am = &acl_main;
+  if (am->fa_sessions_hash_is_initialized)
+    {
+      vlib_cli_output (vm, "\nSession lookup hash table:\n%U\n\n",
+		       format_bihash_40_8, &am->fa_sessions_hash, verbose);
+    }
+  else
+    {
+      vlib_cli_output (vm,
+		       "\nSession lookup hash table is not allocated.\n\n");
+    }
+}
+
+
+/* *INDENT-OFF* */
+
+VLIB_REGISTER_NODE (acl_fa_worker_session_cleaner_process_node, static) = {
+  .function = acl_fa_worker_conn_cleaner_process,
+  .name = "acl-plugin-fa-worker-cleaner-process",
+  .type = VLIB_NODE_TYPE_INPUT,
+  .state = VLIB_NODE_STATE_INTERRUPT,
+};
+
+VLIB_REGISTER_NODE (acl_fa_session_cleaner_process_node, static) = {
+  .function = acl_fa_session_cleaner_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "acl-plugin-fa-cleaner-process",
+  .n_errors = ARRAY_LEN (acl_fa_cleaner_error_strings),
+  .error_strings = acl_fa_cleaner_error_strings,
+  .n_next_nodes = 0,
+  .next_nodes = {},
+};
+
+
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/acl/session_inlines.h b/src/plugins/acl/session_inlines.h
new file mode 100644
index 00000000000..e75582b647b
--- /dev/null
+++ b/src/plugins/acl/session_inlines.h
@@ -0,0 +1,426 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+/* ICMPv4 invert type for stateful ACL */
+static const u8 icmp4_invmap[] = {
+  [ICMP4_echo_reply] = ICMP4_echo_request + 1,
+  [ICMP4_timestamp_reply] = ICMP4_timestamp_request + 1,
+  [ICMP4_information_reply] = ICMP4_information_request + 1,
+  [ICMP4_address_mask_reply] = ICMP4_address_mask_request + 1
+};
+
+/* Supported ICMPv4 messages for session creation */
+static const u8 icmp4_valid_new[] = {
+  [ICMP4_echo_request] = 1,
+  [ICMP4_timestamp_request] = 1,
+  [ICMP4_information_request] = 1,
+  [ICMP4_address_mask_request] = 1
+};
+
+/* ICMPv6 invert type for stateful ACL */
+static const u8 icmp6_invmap[] = {
+  [ICMP6_echo_reply - 128] = ICMP6_echo_request + 1,
+  [ICMP6_node_information_response - 128] = ICMP6_node_information_request + 1
+};
+
+/* Supported ICMPv6 messages for session creation */
+static const u8 icmp6_valid_new[] = {
+  [ICMP6_echo_request - 128] = 1,
+  [ICMP6_node_information_request - 128] = 1
+};
+
+/* IP4 and IP6 protocol numbers of ICMP */
+static u8 icmp_protos[] = { IP_PROTOCOL_ICMP, IP_PROTOCOL_ICMP6 };
+
+
+
+always_inline int
+acl_fa_ifc_has_sessions (acl_main_t * am, int sw_if_index0)
+{
+  return am->fa_sessions_hash_is_initialized;
+}
+
+always_inline int
+acl_fa_ifc_has_in_acl (acl_main_t * am, int sw_if_index0)
+{
+  int it_has = clib_bitmap_get (am->fa_in_acl_on_sw_if_index, sw_if_index0);
+  return it_has;
+}
+
+always_inline int
+acl_fa_ifc_has_out_acl (acl_main_t * am, int sw_if_index0)
+{
+  int it_has = clib_bitmap_get (am->fa_out_acl_on_sw_if_index, sw_if_index0);
+  return it_has;
+}
+
+/* Session keys match the packets received, and mirror the packets sent */
+always_inline u32
+acl_make_5tuple_session_key (acl_main_t * am, int is_input, int is_ip6,
+			     u32 sw_if_index, fa_5tuple_t * p5tuple_pkt,
+			     fa_5tuple_t * p5tuple_sess)
+{
+  int src_index = is_input ? 0 : 1;
+  int dst_index = is_input ? 1 : 0;
+  u32 valid_new_sess = 1;
+  p5tuple_sess->addr[src_index] = p5tuple_pkt->addr[0];
+  p5tuple_sess->addr[dst_index] = p5tuple_pkt->addr[1];
+  p5tuple_sess->l4.as_u64 = p5tuple_pkt->l4.as_u64;
+
+  if (PREDICT_TRUE (p5tuple_pkt->l4.proto != icmp_protos[is_ip6]))
+    {
+      p5tuple_sess->l4.port[src_index] = p5tuple_pkt->l4.port[0];
+      p5tuple_sess->l4.port[dst_index] = p5tuple_pkt->l4.port[1];
+    }
+  else
+    {
+      static const u8 *icmp_invmap[] = { icmp4_invmap, icmp6_invmap };
+      static const u8 *icmp_valid_new[] =
+	{ icmp4_valid_new, icmp6_valid_new };
+      static const u8 icmp_invmap_size[] = { sizeof (icmp4_invmap),
+	sizeof (icmp6_invmap)
+      };
+      static const u8 icmp_valid_new_size[] = { sizeof (icmp4_valid_new),
+	sizeof (icmp6_valid_new)
+      };
+      int type =
+	is_ip6 ? p5tuple_pkt->l4.port[0] - 128 : p5tuple_pkt->l4.port[0];
+
+      p5tuple_sess->l4.port[0] = p5tuple_pkt->l4.port[0];
+      p5tuple_sess->l4.port[1] = p5tuple_pkt->l4.port[1];
+
+      /*
+       * Invert ICMP type for valid icmp_invmap messages:
+       *  1) input node with outbound ACL interface
+       *  2) output node with inbound ACL interface
+       *
+       */
+      if ((is_input && acl_fa_ifc_has_out_acl (am, sw_if_index)) ||
+	  (!is_input && acl_fa_ifc_has_in_acl (am, sw_if_index)))
+	{
+	  if (type >= 0 &&
+	      type <= icmp_invmap_size[is_ip6] && icmp_invmap[is_ip6][type])
+	    {
+	      p5tuple_sess->l4.port[0] = icmp_invmap[is_ip6][type] - 1;
+	    }
+	}
+
+      /*
+       * ONLY ICMP messages defined in icmp4_valid_new/icmp6_valid_new table
+       * are allowed to create stateful ACL.
+       * The other messages will be forwarded without creating a reflexive ACL.
+       */
+      if (type < 0 ||
+	  type > icmp_valid_new_size[is_ip6] || !icmp_valid_new[is_ip6][type])
+	{
+	  valid_new_sess = 0;
+	}
+    }
+
+  return valid_new_sess;
+}
+
+always_inline int
+fa_session_get_timeout_type (acl_main_t * am, fa_session_t * sess)
+{
+  /* seen both SYNs and ACKs but not FINs means we are in establshed state */
+  u16 masked_flags =
+    sess->tcp_flags_seen.as_u16 & ((TCP_FLAGS_RSTFINACKSYN << 8) +
+				   TCP_FLAGS_RSTFINACKSYN);
+  switch (sess->info.l4.proto)
+    {
+    case IPPROTO_TCP:
+      if (((TCP_FLAGS_ACKSYN << 8) + TCP_FLAGS_ACKSYN) == masked_flags)
+	{
+	  return ACL_TIMEOUT_TCP_IDLE;
+	}
+      else
+	{
+	  return ACL_TIMEOUT_TCP_TRANSIENT;
+	}
+      break;
+    case IPPROTO_UDP:
+      return ACL_TIMEOUT_UDP_IDLE;
+      break;
+    default:
+      return ACL_TIMEOUT_UDP_IDLE;
+    }
+}
+
+/*
+ * Get the idle timeout of a session.
+ */
+
+always_inline u64
+fa_session_get_timeout (acl_main_t * am, fa_session_t * sess)
+{
+  u64 timeout = am->vlib_main->clib_time.clocks_per_second;
+  int timeout_type = fa_session_get_timeout_type (am, sess);
+  timeout *= am->session_timeout_sec[timeout_type];
+  return timeout;
+}
+
+
+
+always_inline fa_session_t *
+get_session_ptr (acl_main_t * am, u16 thread_index, u32 session_index)
+{
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  fa_session_t *sess = pool_is_free_index (pw->fa_sessions_pool,
+					   session_index) ? 0 :
+    pool_elt_at_index (pw->fa_sessions_pool,
+		       session_index);
+  return sess;
+}
+
+always_inline int
+is_valid_session_ptr (acl_main_t * am, u16 thread_index, fa_session_t * sess)
+{
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  return ((sess != 0)
+	  && ((sess - pw->fa_sessions_pool) <
+	      pool_len (pw->fa_sessions_pool)));
+}
+
+always_inline void
+acl_fa_conn_list_add_session (acl_main_t * am, fa_full_session_id_t sess_id,
+			      u64 now)
+{
+  fa_session_t *sess =
+    get_session_ptr (am, sess_id.thread_index, sess_id.session_index);
+  u8 list_id = fa_session_get_timeout_type (am, sess);
+  uword thread_index = os_get_thread_index ();
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  /* the retrieved session thread index must be necessarily the same as the one in the key */
+  ASSERT (sess->thread_index == sess_id.thread_index);
+  /* the retrieved session thread index must be the same as current thread */
+  ASSERT (sess->thread_index == thread_index);
+  sess->link_enqueue_time = now;
+  sess->link_list_id = list_id;
+  sess->link_next_idx = ~0;
+  sess->link_prev_idx = pw->fa_conn_list_tail[list_id];
+  if (~0 != pw->fa_conn_list_tail[list_id])
+    {
+      fa_session_t *prev_sess =
+	get_session_ptr (am, thread_index, pw->fa_conn_list_tail[list_id]);
+      prev_sess->link_next_idx = sess_id.session_index;
+      /* We should never try to link with a session on another thread */
+      ASSERT (prev_sess->thread_index == sess->thread_index);
+    }
+  pw->fa_conn_list_tail[list_id] = sess_id.session_index;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+  clib_warning
+    ("FA-SESSION-DEBUG: add session id %d on thread %d sw_if_index %d",
+     sess_id.session_index, thread_index, sess->sw_if_index);
+#endif
+  pw->serviced_sw_if_index_bitmap =
+    clib_bitmap_set (pw->serviced_sw_if_index_bitmap, sess->sw_if_index, 1);
+
+  if (~0 == pw->fa_conn_list_head[list_id])
+    {
+      pw->fa_conn_list_head[list_id] = sess_id.session_index;
+    }
+}
+
+static int
+acl_fa_conn_list_delete_session (acl_main_t * am,
+				 fa_full_session_id_t sess_id)
+{
+  uword thread_index = os_get_thread_index ();
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  if (thread_index != sess_id.thread_index)
+    {
+      /* If another thread attempts to delete the session, fail it. */
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning ("thread id in key %d != curr thread index, not deleting");
+#endif
+      return 0;
+    }
+  fa_session_t *sess =
+    get_session_ptr (am, sess_id.thread_index, sess_id.session_index);
+  /* we should never try to delete the session with another thread index */
+  ASSERT (sess->thread_index == thread_index);
+  if (~0 != sess->link_prev_idx)
+    {
+      fa_session_t *prev_sess =
+	get_session_ptr (am, thread_index, sess->link_prev_idx);
+      /* the previous session must be in the same list as this one */
+      ASSERT (prev_sess->link_list_id == sess->link_list_id);
+      prev_sess->link_next_idx = sess->link_next_idx;
+    }
+  if (~0 != sess->link_next_idx)
+    {
+      fa_session_t *next_sess =
+	get_session_ptr (am, thread_index, sess->link_next_idx);
+      /* The next session must be in the same list as the one we are deleting */
+      ASSERT (next_sess->link_list_id == sess->link_list_id);
+      next_sess->link_prev_idx = sess->link_prev_idx;
+    }
+  if (pw->fa_conn_list_head[sess->link_list_id] == sess_id.session_index)
+    {
+      pw->fa_conn_list_head[sess->link_list_id] = sess->link_next_idx;
+    }
+  if (pw->fa_conn_list_tail[sess->link_list_id] == sess_id.session_index)
+    {
+      pw->fa_conn_list_tail[sess->link_list_id] = sess->link_prev_idx;
+    }
+  return 1;
+}
+
+always_inline int
+acl_fa_restart_timer_for_session (acl_main_t * am, u64 now,
+				  fa_full_session_id_t sess_id)
+{
+  if (acl_fa_conn_list_delete_session (am, sess_id))
+    {
+      acl_fa_conn_list_add_session (am, sess_id, now);
+      return 1;
+    }
+  else
+    {
+      /*
+       * Our thread does not own this connection, so we can not delete
+       * The session. To avoid the complicated signaling, we simply
+       * pick the list waiting time to be the shortest of the timeouts.
+       * This way we do not have to do anything special, and let
+       * the regular requeue check take care of everything.
+       */
+      return 0;
+    }
+}
+
+
+always_inline u8
+acl_fa_track_session (acl_main_t * am, int is_input, u32 sw_if_index, u64 now,
+		      fa_session_t * sess, fa_5tuple_t * pkt_5tuple)
+{
+  sess->last_active_time = now;
+  if (pkt_5tuple->pkt.tcp_flags_valid)
+    {
+      sess->tcp_flags_seen.as_u8[is_input] |= pkt_5tuple->pkt.tcp_flags;
+    }
+  return 3;
+}
+
+
+always_inline void
+acl_fa_delete_session (acl_main_t * am, u32 sw_if_index,
+		       fa_full_session_id_t sess_id)
+{
+  void *oldheap = clib_mem_set_heap (am->acl_mheap);
+  fa_session_t *sess =
+    get_session_ptr (am, sess_id.thread_index, sess_id.session_index);
+  ASSERT (sess->thread_index == os_get_thread_index ());
+  clib_bihash_add_del_40_8 (&am->fa_sessions_hash, &sess->info.kv, 0);
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[sess_id.thread_index];
+  pool_put_index (pw->fa_sessions_pool, sess_id.session_index);
+  /* Deleting from timer structures not needed,
+     as the caller must have dealt with the timers. */
+  vec_validate (pw->fa_session_dels_by_sw_if_index, sw_if_index);
+  clib_mem_set_heap (oldheap);
+  pw->fa_session_dels_by_sw_if_index[sw_if_index]++;
+  clib_smp_atomic_add (&am->fa_session_total_dels, 1);
+}
+
+always_inline int
+acl_fa_can_add_session (acl_main_t * am, int is_input, u32 sw_if_index)
+{
+  u64 curr_sess_count;
+  curr_sess_count = am->fa_session_total_adds - am->fa_session_total_dels;
+  return (curr_sess_count < am->fa_conn_table_max_entries);
+}
+
+
+always_inline void
+acl_fa_try_recycle_session (acl_main_t * am, int is_input, u16 thread_index,
+			    u32 sw_if_index)
+{
+  /* try to recycle a TCP transient session */
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+  u8 timeout_type = ACL_TIMEOUT_TCP_TRANSIENT;
+  fa_full_session_id_t sess_id;
+  sess_id.session_index = pw->fa_conn_list_head[timeout_type];
+  if (~0 != sess_id.session_index)
+    {
+      sess_id.thread_index = thread_index;
+      acl_fa_conn_list_delete_session (am, sess_id);
+      acl_fa_delete_session (am, sw_if_index, sess_id);
+    }
+}
+
+always_inline fa_session_t *
+acl_fa_add_session (acl_main_t * am, int is_input, u32 sw_if_index, u64 now,
+		    fa_5tuple_t * p5tuple, u16 current_policy_epoch)
+{
+  clib_bihash_kv_40_8_t *pkv = &p5tuple->kv;
+  clib_bihash_kv_40_8_t kv;
+  fa_full_session_id_t f_sess_id;
+  uword thread_index = os_get_thread_index ();
+  void *oldheap = clib_mem_set_heap (am->acl_mheap);
+  acl_fa_per_worker_data_t *pw = &am->per_worker_data[thread_index];
+
+  f_sess_id.thread_index = thread_index;
+  fa_session_t *sess;
+
+  pool_get_aligned (pw->fa_sessions_pool, sess, CLIB_CACHE_LINE_BYTES);
+  f_sess_id.session_index = sess - pw->fa_sessions_pool;
+  f_sess_id.intf_policy_epoch = current_policy_epoch;
+
+  kv.key[0] = pkv->key[0];
+  kv.key[1] = pkv->key[1];
+  kv.key[2] = pkv->key[2];
+  kv.key[3] = pkv->key[3];
+  kv.key[4] = pkv->key[4];
+  kv.value = f_sess_id.as_u64;
+
+  memcpy (sess, pkv, sizeof (pkv->key));
+  sess->last_active_time = now;
+  sess->sw_if_index = sw_if_index;
+  sess->tcp_flags_seen.as_u16 = 0;
+  sess->thread_index = thread_index;
+  sess->link_list_id = ~0;
+  sess->link_prev_idx = ~0;
+  sess->link_next_idx = ~0;
+
+
+
+  ASSERT (am->fa_sessions_hash_is_initialized == 1);
+  clib_bihash_add_del_40_8 (&am->fa_sessions_hash, &kv, 1);
+  acl_fa_conn_list_add_session (am, f_sess_id, now);
+
+  vec_validate (pw->fa_session_adds_by_sw_if_index, sw_if_index);
+  clib_mem_set_heap (oldheap);
+  pw->fa_session_adds_by_sw_if_index[sw_if_index]++;
+  clib_smp_atomic_add (&am->fa_session_total_adds, 1);
+  return sess;
+}
+
+always_inline int
+acl_fa_find_session (acl_main_t * am, u32 sw_if_index0, fa_5tuple_t * p5tuple,
+		     clib_bihash_kv_40_8_t * pvalue_sess)
+{
+  return (clib_bihash_search_40_8
+	  (&am->fa_sessions_hash, &p5tuple->kv, pvalue_sess) == 0);
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */