ACL plugin 1.2

L3 path support, L2+L3 unified processing node, skip IPv6 EH support.

Change-Id: Iac37a466ba1c035e5c2997b03c0743bfec5c9a08
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

1 files changed, 1444 insertions, 0 deletions

diff --git a/src/plugins/acl/fa_node.c b/src/plugins/acl/fa_node.c
new file mode 100644
index 00000000..ac619a72
--- /dev/null
+++ b/src/plugins/acl/fa_node.c
@@ -0,0 +1,1444 @@
+/*
+ * 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 "bihash_40_8.h"
+
+#include <vppinfra/bihash_template.h>
+#include <vppinfra/bihash_template.c>
+
+#include "fa_node.h"
+
+typedef struct
+{
+  u32 next_index;
+  u32 sw_if_index;
+  u32 match_acl_in_index;
+  u32 match_rule_index;
+  u64 packet_info[6];
+  u32 trace_bitmap;
+  u8 action;
+} acl_fa_trace_t;
+
+/* 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: 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->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]);
+  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 void *
+get_ptr_to_offset (vlib_buffer_t * b0, int offset)
+{
+  u8 *p = vlib_buffer_get_current (b0) + offset;
+  return p;
+}
+
+
+static int
+fa_acl_match_addr (ip46_address_t * addr1, ip46_address_t * addr2,
+		   int prefixlen, int is_ip6)
+{
+  if (prefixlen == 0)
+    {
+      /* match any always succeeds */
+      return 1;
+    }
+  if (is_ip6)
+    {
+      if (memcmp (addr1, addr2, prefixlen / 8))
+	{
+	  /* If the starting full bytes do not match, no point in bittwidling the thumbs further */
+	  return 0;
+	}
+      if (prefixlen % 8)
+	{
+	  u8 b1 = *((u8 *) addr1 + 1 + prefixlen / 8);
+	  u8 b2 = *((u8 *) addr2 + 1 + prefixlen / 8);
+	  u8 mask0 = (0xff - ((1 << (8 - (prefixlen % 8))) - 1));
+	  return (b1 & mask0) == b2;
+	}
+      else
+	{
+	  /* The prefix fits into integer number of bytes, so nothing left to do */
+	  return 1;
+	}
+    }
+  else
+    {
+      uint32_t a1 = ntohl (addr1->ip4.as_u32);
+      uint32_t a2 = ntohl (addr2->ip4.as_u32);
+      uint32_t mask0 = 0xffffffff - ((1 << (32 - prefixlen)) - 1);
+      return (a1 & mask0) == a2;
+    }
+}
+
+static int
+fa_acl_match_port (u16 port, u16 port_first, u16 port_last, int is_ip6)
+{
+  return ((port >= port_first) && (port <= port_last));
+}
+
+int
+acl_match_5tuple (acl_main_t * am, u32 acl_index, fa_5tuple_t * pkt_5tuple,
+		  int is_ip6, u8 * r_action, u32 * r_acl_match_p,
+		  u32 * r_rule_match_p, u32 * trace_bitmap)
+{
+  int i;
+  acl_list_t *a;
+  acl_rule_t *r;
+
+  if (pool_is_free_index (am->acls, acl_index))
+    {
+      if (r_acl_match_p)
+	*r_acl_match_p = acl_index;
+      if (r_rule_match_p)
+	*r_rule_match_p = -1;
+      /* the ACL does not exist but is used for policy. Block traffic. */
+      return 0;
+    }
+  a = am->acls + acl_index;
+  for (i = 0; i < a->count; i++)
+    {
+      r = a->rules + i;
+      if (is_ip6 != r->is_ipv6)
+	{
+	  continue;
+	}
+      if (!fa_acl_match_addr
+	  (&pkt_5tuple->addr[1], &r->dst, r->dst_prefixlen, is_ip6))
+	continue;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning
+	("ACL_FA_NODE_DBG acl %d rule %d pkt dst addr %U match rule addr %U/%d",
+	 acl_index, i, format_ip46_address, &pkt_5tuple->addr[1],
+	 IP46_TYPE_ANY, format_ip46_address, &r->dst, IP46_TYPE_ANY,
+	 r->dst_prefixlen);
+#endif
+
+      if (!fa_acl_match_addr
+	  (&pkt_5tuple->addr[0], &r->src, r->src_prefixlen, is_ip6))
+	continue;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning
+	("ACL_FA_NODE_DBG acl %d rule %d pkt src addr %U match rule addr %U/%d",
+	 acl_index, i, format_ip46_address, &pkt_5tuple->addr[0],
+	 IP46_TYPE_ANY, format_ip46_address, &r->src, IP46_TYPE_ANY,
+	 r->src_prefixlen);
+      clib_warning
+	("ACL_FA_NODE_DBG acl %d rule %d trying to match pkt proto %d with rule %d",
+	 acl_index, i, pkt_5tuple->l4.proto, r->proto);
+#endif
+      if (r->proto)
+	{
+	  if (pkt_5tuple->l4.proto != r->proto)
+	    continue;
+	  /* A sanity check just to ensure what we jave just matched was a valid L4 extracted from the packet */
+	  if (PREDICT_FALSE (!pkt_5tuple->pkt.l4_valid))
+	    continue;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning
+	    ("ACL_FA_NODE_DBG acl %d rule %d pkt proto %d match rule %d",
+	     acl_index, i, pkt_5tuple->l4.proto, r->proto);
+#endif
+
+	  if (!fa_acl_match_port
+	      (pkt_5tuple->l4.port[0], r->src_port_or_type_first,
+	       r->src_port_or_type_last, is_ip6))
+	    continue;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning
+	    ("ACL_FA_NODE_DBG acl %d rule %d pkt sport %d match rule [%d..%d]",
+	     acl_index, i, pkt_5tuple->l4.port[0], r->src_port_or_type_first,
+	     r->src_port_or_type_last);
+#endif
+
+	  if (!fa_acl_match_port
+	      (pkt_5tuple->l4.port[1], r->dst_port_or_code_first,
+	       r->dst_port_or_code_last, is_ip6))
+	    continue;
+
+#ifdef FA_NODE_VERBOSE_DEBUG
+	  clib_warning
+	    ("ACL_FA_NODE_DBG acl %d rule %d pkt dport %d match rule [%d..%d]",
+	     acl_index, i, pkt_5tuple->l4.port[1], r->dst_port_or_code_first,
+	     r->dst_port_or_code_last);
+#endif
+	  if (pkt_5tuple->pkt.tcp_flags_valid
+	      && ((pkt_5tuple->pkt.tcp_flags & r->tcp_flags_mask) !=
+		  r->tcp_flags_value))
+	    continue;
+	}
+      /* everything matches! */
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning ("ACL_FA_NODE_DBG acl %d rule %d FULL-MATCH, action %d",
+		    acl_index, i, r->is_permit);
+#endif
+      *r_action = r->is_permit;
+      if (r_acl_match_p)
+	*r_acl_match_p = acl_index;
+      if (r_rule_match_p)
+	*r_rule_match_p = i;
+      return 1;
+    }
+  return 0;
+}
+
+static u8
+full_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
+		       int is_ip6, int is_input, u32 * acl_match_p,
+		       u32 * rule_match_p, u32 * trace_bitmap)
+{
+  acl_main_t *am = &acl_main;
+  int i;
+  u32 *acl_vector;
+  u8 action = 0;
+
+  if (is_input)
+    {
+      vec_validate (am->input_acl_vec_by_sw_if_index, sw_if_index);
+      acl_vector = am->input_acl_vec_by_sw_if_index[sw_if_index];
+    }
+  else
+    {
+      vec_validate (am->output_acl_vec_by_sw_if_index, sw_if_index);
+      acl_vector = am->output_acl_vec_by_sw_if_index[sw_if_index];
+    }
+  for (i = 0; i < vec_len (acl_vector); i++)
+    {
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning ("ACL_FA_NODE_DBG: Trying to match ACL: %d",
+		    acl_vector[i]);
+#endif
+      if (acl_match_5tuple
+	  (am, acl_vector[i], pkt_5tuple, is_ip6, &action,
+	   acl_match_p, rule_match_p, trace_bitmap))
+	{
+	  return action;
+	}
+    }
+  if (vec_len (acl_vector) > 0)
+    {
+      /* If there are ACLs and none matched, deny by default */
+      return 0;
+    }
+#ifdef FA_NODE_VERBOSE_DEBUG
+  clib_warning ("ACL_FA_NODE_DBG: No ACL on sw_if_index %d", sw_if_index);
+#endif
+  /* Deny by default. If there are no ACLs defined we should not be here. */
+  return 0;
+}
+
+static int
+offset_within_packet (vlib_buffer_t * b0, int offset)
+{
+  /* For the purposes of this code, "within" means we have at least 8 bytes after it */
+  return (offset < (b0->current_length - 8));
+}
+
+static void
+acl_fill_5tuple (acl_main_t * am, vlib_buffer_t * b0, int is_ip6,
+		 int is_input, int is_l2_path, fa_5tuple_t * p5tuple_pkt)
+{
+  int l3_offset = 14;
+  int l4_offset;
+  u16 ports[2];
+  u16 proto;
+  /* IP4 and IP6 protocol numbers of ICMP */
+  static u8 icmp_protos[] = { IP_PROTOCOL_ICMP, IP_PROTOCOL_ICMP6 };
+
+  if (is_input && !(is_l2_path))
+    {
+      l3_offset = 0;
+    }
+
+
+  if (is_ip6)
+    {
+      clib_memcpy (&p5tuple_pkt->addr,
+		   get_ptr_to_offset (b0,
+				      offsetof (ip6_header_t,
+						src_address) + l3_offset),
+		   sizeof (p5tuple_pkt->addr));
+      proto =
+	*(u8 *) get_ptr_to_offset (b0,
+				   offsetof (ip6_header_t,
+					     protocol) + l3_offset);
+      l4_offset = l3_offset + sizeof (ip6_header_t);
+#ifdef FA_NODE_VERBOSE_DEBUG
+      clib_warning ("ACL_FA_NODE_DBG: proto: %d, l4_offset: %d", proto,
+		    l4_offset);
+#endif
+      /* IP6 EH handling is here, increment l4_offset if needs to, update the proto */
+      int need_skip_eh = clib_bitmap_get (am->fa_ipv6_known_eh_bitmap, proto);
+      if (PREDICT_FALSE (need_skip_eh))
+	{
+	  /* FIXME: add fragment header special handling. Currently causes treated as unknown header. */
+	  while (need_skip_eh && offset_within_packet (b0, l4_offset))
+	    {
+	      u8 nwords = *(u8 *) get_ptr_to_offset (b0, 1 + l4_offset);
+	      proto = *(u8 *) get_ptr_to_offset (b0, l4_offset);
+	      l4_offset += 8 * (1 + (u16) nwords);
+#ifdef FA_NODE_VERBOSE_DEBUG
+	      clib_warning ("ACL_FA_NODE_DBG: new proto: %d, new offset: %d",
+			    proto, l4_offset);
+#endif
+	      need_skip_eh =
+		clib_bitmap_get (am->fa_ipv6_known_eh_bitmap, proto);
+	    }
+	}
+    }
+  else
+    {
+      p5tuple_pkt->kv.key[0] = 0;
+      p5tuple_pkt->kv.key[1] = 0;
+      p5tuple_pkt->kv.key[2] = 0;
+      p5tuple_pkt->kv.key[3] = 0;
+      clib_memcpy (&p5tuple_pkt->addr[0].ip4,
+		   get_ptr_to_offset (b0,
+				      offsetof (ip4_header_t,
+						src_address) + l3_offset),
+		   sizeof (p5tuple_pkt->addr[0].ip4));
+      clib_memcpy (&p5tuple_pkt->addr[1].ip4,
+		   get_ptr_to_offset (b0,
+				      offsetof (ip4_header_t,
+						dst_address) + l3_offset),
+		   sizeof (p5tuple_pkt->addr[1].ip4));
+      proto =
+	*(u8 *) get_ptr_to_offset (b0,
+				   offsetof (ip4_header_t,
+					     protocol) + l3_offset);
+      l4_offset = l3_offset + sizeof (ip4_header_t);
+    }
+  /* Remainder of the key and per-packet non-key data */
+  p5tuple_pkt->kv.key[4] = 0;
+  p5tuple_pkt->kv.value = 0;
+  if (PREDICT_TRUE (offset_within_packet (b0, l4_offset)))
+    {
+      p5tuple_pkt->l4.proto = proto;
+      p5tuple_pkt->pkt.l4_valid = 1;
+      if (icmp_protos[is_ip6] == proto)
+	{
+	  /* type */
+	  p5tuple_pkt->l4.port[0] =
+	    *(u8 *) get_ptr_to_offset (b0,
+				       l4_offset + offsetof (icmp46_header_t,
+							     type));
+	  /* code */
+	  p5tuple_pkt->l4.port[1] =
+	    *(u8 *) get_ptr_to_offset (b0,
+				       l4_offset + offsetof (icmp46_header_t,
+							     code));
+	}
+      else if ((IPPROTO_TCP == proto) || (IPPROTO_UDP == proto))
+	{
+	  clib_memcpy (&ports,
+		       get_ptr_to_offset (b0,
+					  l4_offset + offsetof (tcp_header_t,
+								src_port)),
+		       sizeof (ports));
+	  p5tuple_pkt->l4.port[0] = ntohs (ports[0]);
+	  p5tuple_pkt->l4.port[1] = ntohs (ports[1]);
+
+	  p5tuple_pkt->pkt.tcp_flags =
+	    *(u8 *) get_ptr_to_offset (b0,
+				       l4_offset + offsetof (tcp_header_t,
+							     flags));
+	  p5tuple_pkt->pkt.tcp_flags_valid = (proto == IPPROTO_TCP);
+	}
+      /*
+       * FIXME: rather than the above conditional, here could
+       * be a nice generic mechanism to extract two L4 values:
+       *
+       * have a per-protocol array of 4 elements like this:
+       *   u8 offset; to take the byte from, off L4 header
+       *   u8 mask; to mask it with, before storing
+       *
+       * this way we can describe UDP, TCP and ICMP[46] semantics,
+       * and add a sort of FPM-type behavior for other protocols.
+       *
+       * Of course, is it faster ? and is it needed ?
+       *
+       */
+    }
+}
+
+
+/* Session keys match the packets received, and mirror the packets sent */
+static void
+acl_make_5tuple_session_key (int is_input, fa_5tuple_t * p5tuple_pkt,
+			     fa_5tuple_t * p5tuple_sess)
+{
+  int src_index = is_input ? 0 : 1;
+  int dst_index = is_input ? 1 : 0;
+  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;
+  p5tuple_sess->l4.port[src_index] = p5tuple_pkt->l4.port[0];
+  p5tuple_sess->l4.port[dst_index] = p5tuple_pkt->l4.port[1];
+}
+
+
+static int
+acl_fa_ifc_has_sessions (acl_main_t * am, int sw_if_index0)
+{
+  int has_sessions =
+    clib_bitmap_get (am->fa_sessions_on_sw_if_index, sw_if_index0);
+  return has_sessions;
+}
+
+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;
+}
+
+
+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_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_ifc_init_sessions (acl_main_t * am, int sw_if_index0)
+{
+#ifdef FA_NODE_VERBOSE_DEBUG
+  clib_warning
+    ("Initializing bihash for sw_if_index %d num buckets %lu memory size %llu",
+     sw_if_index0, am->fa_conn_table_hash_num_buckets,
+     am->fa_conn_table_hash_memory_size);
+#endif
+  vec_validate (am->fa_sessions_by_sw_if_index, sw_if_index0);
+  BV (clib_bihash_init) (&am->fa_sessions_by_sw_if_index
+			 [sw_if_index0], "ACL plugin FA session bihash",
+			 am->fa_conn_table_hash_num_buckets,
+			 am->fa_conn_table_hash_memory_size);
+  am->fa_sessions_on_sw_if_index =
+    clib_bitmap_set (am->fa_sessions_on_sw_if_index, sw_if_index0, 1);
+}
+
+static void
+acl_fa_conn_list_add_session (acl_main_t * am, u32 sess_id)
+{
+  fa_session_t *sess = am->fa_sessions_pool + sess_id;
+  u8 list_id = fa_session_get_timeout_type(am, sess);
+  sess->link_list_id = list_id;
+  sess->link_next_idx = ~0;
+  sess->link_prev_idx = am->fa_conn_list_tail[list_id];
+  if (~0 != am->fa_conn_list_tail[list_id]) {
+    fa_session_t *prev_sess = am->fa_sessions_pool + am->fa_conn_list_tail[list_id];
+    prev_sess->link_next_idx = sess_id;
+  }
+  am->fa_conn_list_tail[list_id] = sess_id;
+
+  if (~0 == am->fa_conn_list_head[list_id]) {
+    am->fa_conn_list_head[list_id] = sess_id;
+  }
+}
+
+static void
+acl_fa_conn_list_delete_session (acl_main_t *am, u32 sess_id)
+{
+  fa_session_t *sess = am->fa_sessions_pool + sess_id;
+  if (~0 != sess->link_prev_idx) {
+    fa_session_t *prev_sess = am->fa_sessions_pool + sess->link_prev_idx;
+    prev_sess->link_next_idx = sess->link_next_idx;
+    if (prev_sess->link_list_id != sess->link_list_id)
+      clib_warning("(prev_sess->link_list_id != sess->link_list_id)");
+  }
+  if (~0 != sess->link_next_idx) {
+    fa_session_t *next_sess = am->fa_sessions_pool + sess->link_next_idx;
+    next_sess->link_prev_idx = sess->link_prev_idx;
+    if (next_sess->link_list_id != sess->link_list_id)
+      clib_warning("(next_sess->link_list_id != sess->link_list_id)");
+  }
+  if (am->fa_conn_list_head[sess->link_list_id] == sess_id) {
+    am->fa_conn_list_head[sess->link_list_id] = sess->link_next_idx;
+  }
+  if (am->fa_conn_list_tail[sess->link_list_id] == sess_id) {
+    am->fa_conn_list_tail[sess->link_list_id] = sess->link_next_idx;
+  }
+}
+
+
+int
+acl_fa_session_is_dead (acl_main_t * am, u32 sw_if_index, u64 now,
+			u32 sess_id)
+{
+  return 0;
+}
+
+static void
+acl_fa_restart_timer_for_session (acl_main_t * am, u64 now, u32 sess_id)
+{
+  // fa_session_t *sess = am->fa_sessions_pool + sess_id;
+  acl_fa_conn_list_delete_session(am, sess_id);
+  acl_fa_conn_list_add_session(am, sess_id);
+}
+
+
+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, u32 sess_id)
+{
+  fa_session_t *sess = (fa_session_t *) am->fa_sessions_pool + sess_id;
+  BV (clib_bihash_add_del) (&am->fa_sessions_by_sw_if_index[sw_if_index],
+			    &sess->info.kv, 0);
+  pool_put_index (am->fa_sessions_pool, sess_id);
+  /* Deleting from timer wheel not needed, as the cleaner deals with the timers. */
+  vec_validate (am->fa_session_dels_by_sw_if_index, sw_if_index);
+  am->fa_session_dels_by_sw_if_index[sw_if_index]++;
+}
+
+static int
+acl_fa_can_add_session (acl_main_t * am, int is_input, u32 sw_if_index)
+{
+  u64 curr_sess;
+  vec_validate (am->fa_session_adds_by_sw_if_index, sw_if_index);
+  vec_validate (am->fa_session_dels_by_sw_if_index, sw_if_index);
+  curr_sess =
+    am->fa_session_adds_by_sw_if_index[sw_if_index] -
+    am->fa_session_dels_by_sw_if_index[sw_if_index];
+  return (curr_sess < am->fa_conn_table_max_entries);
+}
+
+always_inline void
+acl_fa_try_recycle_session (acl_main_t * am, int is_input, u32 sw_if_index)
+{
+  /* try to recycle a TCP transient session */
+  u8 timeout_type = ACL_TIMEOUT_TCP_TRANSIENT;
+  u32 sess_id = am->fa_conn_list_head[timeout_type];
+  if (~0 != sess_id) {
+    acl_fa_conn_list_delete_session(am, sess_id);
+    acl_fa_delete_session(am, sw_if_index, sess_id);
+  }
+}
+
+static void
+acl_fa_add_session (acl_main_t * am, int is_input, u32 sw_if_index, u64 now,
+		    fa_5tuple_t * p5tuple)
+{
+  clib_bihash_kv_40_8_t *pkv = &p5tuple->kv;
+  clib_bihash_kv_40_8_t kv;
+  u32 sess_id;
+  fa_session_t *sess;
+
+  pool_get (am->fa_sessions_pool, sess);
+  sess_id = sess - am->fa_sessions_pool;
+
+
+  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 = sess_id;
+
+  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->reserved1 = 0;
+  sess->link_list_id = ~0;
+  sess->link_prev_idx = ~0;
+  sess->link_next_idx = ~0;
+
+
+
+  if (!acl_fa_ifc_has_sessions (am, sw_if_index))
+    {
+      acl_fa_ifc_init_sessions (am, sw_if_index);
+    }
+
+  BV (clib_bihash_add_del) (&am->fa_sessions_by_sw_if_index[sw_if_index],
+			    &kv, 1);
+  acl_fa_conn_list_add_session(am, sess_id);
+
+  vec_validate (am->fa_session_adds_by_sw_if_index, sw_if_index);
+  am->fa_session_adds_by_sw_if_index[sw_if_index]++;
+}
+
+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 (BV (clib_bihash_search)
+	  (&am->fa_sessions_by_sw_if_index[sw_if_index0], &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;
+  u32 feature_bitmap0;
+  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 ();
+
+  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;
+	  int acl_check_needed = 1;
+	  u32 match_acl_in_index = ~0;
+	  u32 match_rule_index = ~0;
+	  u8 error0 = 0;
+
+	  /* 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_l2_path)
+	    feature_bitmap0 = vnet_buffer (b0)->l2.feature_bitmap;
+
+	  /*
+	   * 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_fill_5tuple (am, b0, is_ip6, is_input, is_l2_path, &fa_5tuple);
+	  acl_make_5tuple_session_key (is_input, &fa_5tuple, &kv_sess);
+#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;
+		  // FIXME assert(value_sess.value == (0xffffffff & value_sess.value));
+		  u32 sess_id = value_sess.value;
+		  fa_session_t *sess = am->fa_sessions_pool + sess_id;
+		  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 = sess_id;
+		  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, sess_id);
+		      pkts_restart_session_timer++;
+		      trace_bitmap |=
+			0x00010000 + ((0xff & old_timeout_type) << 8) +
+			(0xff & new_timeout_type);
+		    }
+		}
+	    }
+
+	  if (acl_check_needed)
+	    {
+	      action =
+		full_acl_match_5tuple (sw_if_index0, &fa_5tuple, is_l2_path,
+				       is_ip6, is_input, &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, sw_if_index0);
+
+		  if (acl_fa_can_add_session (am, is_input, sw_if_index0))
+		    {
+                      acl_fa_add_session (am, is_input, sw_if_index0, now,
+					  &kv_sess);
+		      pkts_new_session += 1;
+		    }
+		  else
+		    {
+		      action = 0;
+		      error0 = ACL_FA_ERROR_ACL_TOO_MANY_SESSIONS;
+		    }
+		}
+	    }
+
+
+
+	  if (action > 0)
+	    {
+	      if (is_l2_path)
+		next0 =
+		  feat_bitmap_get_next_node_index (l2_feat_next_node_index,
+						   feature_bitmap0);
+	      else
+		vnet_feature_next (sw_if_index0, &next0, b0);
+	    }
+
+	  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->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 performs all the connection clean up - both for idle connections,
+ * as well as receiving the signals to clean up the connections in case of sw_if_index deletion,
+ * or (maybe in the future) the connection deletion due to policy reasons.
+ *
+ * The previous iteration (l2sess) attempted to clean up the connections in small increments,
+ * in-band, but the problem it tried to preemptively address (process starvation) is yet to be seen.
+ *
+ * The approach with a single thread deleting the connections is simpler, thus we use it until
+ * there is a real starvation problem to solve.
+ *
+ */
+
+
+/* *INDENT-OFF* */
+#define foreach_acl_fa_cleaner_error \
+_(EVENT_CYCLE, "event processing cycle")  \
+_(TIMER_RESTARTED, "restarted session timers")  \
+_(DELETED_SESSIONS, "deleted sessions")  \
+_(ALREADY_DELETED, "timer event for already deleted session")  \
+_(DELETE_BY_SW_IF_INDEX, "delete by sw_if_index event")  \
+_(DELETE_BY_SW_IF_INDEX_OK, "delete by sw_if_index completed ok")  \
+_(WAIT_WITHOUT_TIMEOUT, "process waits without timeout")  \
+_(WAIT_WITH_TIMEOUT, "process waits with timeout")  \
+_(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 _
+};
+
+static int
+acl_fa_clean_sessions_by_sw_if_index (acl_main_t *am, u32 sw_if_index, u32 *count)
+{
+
+  int undeleted = 0;
+  fa_session_t *sess;
+  uword *dv = NULL;
+  uword *ii;
+
+  pool_foreach(sess, am->fa_sessions_pool, ({
+    if ( (~0 == sw_if_index) || (sw_if_index == sess->sw_if_index) )
+      vec_add1(dv, sess-am->fa_sessions_pool);
+  }));
+  vec_foreach(ii, dv)
+  {
+    sess =  pool_elt_at_index(am->fa_sessions_pool, *ii);
+    acl_fa_delete_session(am, sess->sw_if_index, *ii);
+    (*count)++;
+  }
+
+  pool_foreach(sess, am->fa_sessions_pool, ({
+    if ( (~0 == sw_if_index) || (sw_if_index == sess->sw_if_index) )
+      undeleted++;
+  }));
+  if (undeleted == 0)
+    {
+      if (~0 == sw_if_index)
+        {
+          /* FIXME: clean-up tables ? */
+        }
+      else
+        {
+          /* FIXME: clean-up tables ? */
+        }
+    }
+  return (undeleted == 0);
+}
+/* *INDENT-ON* */
+
+static vlib_node_registration_t acl_fa_session_cleaner_process_node;
+
+static int
+acl_fa_conn_has_timed_out (acl_main_t *am, u64 now, u32 session_index)
+{
+  fa_session_t *sess = am->fa_sessions_pool + session_index;
+  u64 sess_timeout_time =
+              sess->last_active_time + fa_session_get_timeout (am, sess);
+  return (sess_timeout_time < now);
+}
+
+
+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 = clib_cpu_time_now ();
+  f64 cpu_cps = vm->clib_time.clocks_per_second;
+  u64 next_expire;
+  /* We should call timer wheel at least twice a second */
+  u64 max_timer_wait_interval = cpu_cps / 2; 
+  am->fa_current_cleaner_timer_wait_interval = max_timer_wait_interval;
+
+  u32 *expired = NULL;
+  uword event_type, *event_data = 0;
+
+  am->fa_cleaner_node_index = acl_fa_session_cleaner_process_node.index;
+
+  while (1)
+    {
+      u32 count_deleted_sessions = 0;
+      u32 count_already_deleted = 0;
+      u32 count_timer_restarted = 0;
+      now = clib_cpu_time_now ();
+      next_expire = now + am->fa_current_cleaner_timer_wait_interval;
+
+	{
+	  f64 timeout = ((i64) next_expire - (i64) now) / cpu_cps;
+	  if (timeout <= 0)
+	    {
+	      /* skip waiting altogether */
+	      event_type = ~0;
+	    }
+	  else
+	    {
+	      /* Timing wheel code is happier if it is called regularly */
+	      if (timeout > 0.5)
+		timeout = 0.5;
+	      vlib_node_increment_counter (vm,
+					   acl_fa_session_cleaner_process_node.
+					   index,
+					   ACL_FA_CLEANER_ERROR_WAIT_WITH_TIMEOUT,
+					   1);
+	      (void) vlib_process_wait_for_event_or_clock (vm, timeout);
+	      event_type = vlib_process_get_events (vm, &event_data);
+	    }
+	}
+
+      now = clib_cpu_time_now ();
+      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 *sw_if_index0;
+	    vec_foreach (sw_if_index0, event_data)
+	    {
+	      vlib_node_increment_counter (vm,
+					   acl_fa_session_cleaner_process_node.
+					   index,
+					   ACL_FA_CLEANER_ERROR_DELETE_BY_SW_IF_INDEX,
+					   1);
+#ifdef FA_NODE_VERBOSE_DEBUG
+	      clib_warning
+		("ACL_FA_NODE_CLEAN: ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX: %d",
+		 *sw_if_index0);
+#endif
+	      u32 count = 0;
+	      int result =
+		acl_fa_clean_sessions_by_sw_if_index (am, *sw_if_index0,
+						      &count);
+	      count_deleted_sessions += count;
+	      vlib_node_increment_counter (vm,
+					   acl_fa_session_cleaner_process_node.
+					   index,
+					   ACL_FA_CLEANER_ERROR_DELETE_BY_SW_IF_INDEX_OK,
+					   result);
+	    }
+	  }
+	  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);
+	  break;
+	}
+
+      {
+        u8 tt = 0;
+        for(tt = 0; tt < ACL_N_TIMEOUTS; tt++) {
+          while((vec_len(expired) < 2*am->fa_max_deleted_sessions_per_interval) && (~0 != am->fa_conn_list_head[tt]) && (acl_fa_conn_has_timed_out(am, now, am->fa_conn_list_head[tt]))) {
+            u32 sess_id = am->fa_conn_list_head[tt];
+            vec_add1(expired, sess_id);
+            acl_fa_conn_list_delete_session(am, sess_id);
+          }
+        }
+      }
+
+
+      u32 *psid = NULL;
+      vec_foreach (psid, expired)
+      {
+	u32 session_index = *psid;
+	if (!pool_is_free_index (am->fa_sessions_pool, session_index))
+	  {
+	    fa_session_t *sess = am->fa_sessions_pool + 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)
+	      {
+		/* clib_warning ("ACL_FA_NODE_CLEAN: Restarting timer for session %d",
+		   (int) session_index); */
+
+		/* Pretend we did this in the past, at last_active moment */
+		count_timer_restarted++;
+	      }
+	    else
+	      {
+		/* clib_warning ("ACL_FA_NODE_CLEAN: Deleting session %d",
+		   (int) session_index); */
+		acl_fa_delete_session (am, sw_if_index, session_index);
+		count_deleted_sessions++;
+	      }
+	  }
+	else
+	  {
+	    count_already_deleted++;
+	  }
+      }
+      if (expired)
+	_vec_len (expired) = 0;
+      if (event_data)
+	_vec_len (event_data) = 0;
+
+      if (count_deleted_sessions > am->fa_max_deleted_sessions_per_interval) {
+        /* if there was too many sessions to delete, do less waiting around next time */
+        am->fa_current_cleaner_timer_wait_interval /= 2;
+      } else if (count_deleted_sessions < am->fa_min_deleted_sessions_per_interval) {
+        /* Too few deleted sessions, 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;
+      }
+
+      vlib_node_increment_counter (vm,
+				   acl_fa_session_cleaner_process_node.index,
+				   ACL_FA_CLEANER_ERROR_EVENT_CYCLE, 1);
+      vlib_node_increment_counter (vm,
+				   acl_fa_session_cleaner_process_node.index,
+				   ACL_FA_CLEANER_ERROR_TIMER_RESTARTED,
+				   count_timer_restarted);
+      vlib_node_increment_counter (vm,
+				   acl_fa_session_cleaner_process_node.index,
+				   ACL_FA_CLEANER_ERROR_DELETED_SESSIONS,
+				   count_deleted_sessions);
+      vlib_node_increment_counter (vm,
+				   acl_fa_session_cleaner_process_node.index,
+				   ACL_FA_CLEANER_ERROR_ALREADY_DELETED,
+				   count_already_deleted);
+    }
+  /* 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 (is_input)
+    {
+      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);
+      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
+    {
+      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);
+      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)))
+    {
+      vlib_process_signal_event (am->vlib_main, am->fa_cleaner_node_index,
+				 ACL_FA_CLEANER_DELETE_BY_SW_IF_INDEX,
+				 sw_if_index);
+    }
+}
+
+
+
+/* *INDENT-OFF* */
+
+
+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* */