bfd: use tw_timer_template instead of legacy wheel
[vpp.git] / src / vnet / bfd / bfd_udp.c
index 5464ce9..0edf8a8 100644 (file)
@@ -29,6 +29,7 @@
 #include <vnet/ip/ip4.h>
 #include <vnet/ip/ip6.h>
 #include <vnet/ip/ip6_packet.h>
+#include <vnet/ip/ip6_link.h>
 #include <vnet/adj/adj.h>
 #include <vnet/adj/adj_nbr.h>
 #include <vnet/dpo/receive_dpo.h>
@@ -59,8 +60,16 @@ typedef struct
   u32 ip4_rewrite_idx;
   /* node index of "ip6-rewrite" node */
   u32 ip6_rewrite_idx;
+  /* node index of "ip4-midchain" node */
+  u32 ip4_midchain_idx;
+  /* node index of "ip6-midchain" node */
+  u32 ip6_midchain_idx;
   /* log class */
   vlib_log_class_t log_class;
+  /* number of active udp4 sessions */
+  u32 udp4_sessions_count;
+  /* number of active udp6 sessions */
+  u32 udp6_sessions_count;
 } bfd_udp_main_t;
 
 static vlib_node_registration_t bfd_udp4_input_node;
@@ -74,7 +83,7 @@ vnet_api_error_t
 bfd_udp_set_echo_source (u32 sw_if_index)
 {
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main, sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main, sw_if_index);
   if (sw_if)
     {
       bfd_udp_main.echo_source_sw_if_index = sw_if_index;
@@ -106,8 +115,8 @@ bfd_udp_is_echo_available (bfd_transport_e transport)
    * pick an unused address from that subnet
    */
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main,
-                               bfd_udp_main.echo_source_sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main,
+                                  bfd_udp_main.echo_source_sw_if_index);
   if (sw_if && sw_if->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
     {
       if (BFD_TRANSPORT_UDP4 == transport)
@@ -261,7 +270,7 @@ bfd_add_udp4_transport (vlib_main_t * vm, u32 bi, const bfd_session_t * bs,
   ip4_udp_headers *headers = NULL;
   vlib_buffer_advance (b, -sizeof (*headers));
   headers = vlib_buffer_get_current (b);
-  memset (headers, 0, sizeof (*headers));
+  clib_memset (headers, 0, sizeof (*headers));
   headers->ip4.ip_version_and_header_length = 0x45;
   headers->ip4.ttl = 255;
   headers->ip4.protocol = IP_PROTOCOL_UDP;
@@ -316,7 +325,7 @@ bfd_add_udp6_transport (vlib_main_t * vm, u32 bi, const bfd_session_t * bs,
   ip6_udp_headers *headers = NULL;
   vlib_buffer_advance (b, -sizeof (*headers));
   headers = vlib_buffer_get_current (b);
-  memset (headers, 0, sizeof (*headers));
+  clib_memset (headers, 0, sizeof (*headers));
   headers->ip6.ip_version_traffic_class_and_flow_label =
     clib_host_to_net_u32 (0x6 << 28);
   headers->ip6.hop_limit = 255;
@@ -330,17 +339,17 @@ bfd_add_udp6_transport (vlib_main_t * vm, u32 bi, const bfd_session_t * bs,
        {
          return rv;
        }
-      clib_memcpy (&headers->ip6.dst_address, &key->local_addr.ip6,
-                  sizeof (headers->ip6.dst_address));
+      clib_memcpy_fast (&headers->ip6.dst_address, &key->local_addr.ip6,
+                       sizeof (headers->ip6.dst_address));
 
       headers->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_bfd_echo6);
     }
   else
     {
-      clib_memcpy (&headers->ip6.src_address, &key->local_addr.ip6,
-                  sizeof (headers->ip6.src_address));
-      clib_memcpy (&headers->ip6.dst_address, &key->peer_addr.ip6,
-                  sizeof (headers->ip6.dst_address));
+      clib_memcpy_fast (&headers->ip6.src_address, &key->local_addr.ip6,
+                       sizeof (headers->ip6.src_address));
+      clib_memcpy_fast (&headers->ip6.dst_address, &key->peer_addr.ip6,
+                       sizeof (headers->ip6.dst_address));
       headers->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_bfd6);
     }
 
@@ -375,8 +384,14 @@ bfd_create_frame_to_next_node (vlib_main_t * vm, u32 bi, u32 next_node)
 int
 bfd_udp_calc_next_node (const struct bfd_session_s *bs, u32 * next_node)
 {
+  vnet_main_t *vnm = vnet_get_main ();
   const bfd_udp_session_t *bus = &bs->udp;
   ip_adjacency_t *adj = adj_get (bus->adj_index);
+
+  /* don't try to send the buffer if the interface is not up */
+  if (!vnet_sw_interface_is_up (vnm, bus->key.sw_if_index))
+    return 0;
+
   switch (adj->lookup_next_index)
     {
     case IP_LOOKUP_NEXT_ARP:
@@ -401,6 +416,17 @@ bfd_udp_calc_next_node (const struct bfd_session_s *bs, u32 * next_node)
          return 1;
        }
       break;
+    case IP_LOOKUP_NEXT_MIDCHAIN:
+      switch (bs->transport)
+       {
+       case BFD_TRANSPORT_UDP4:
+         *next_node = bfd_udp_main.ip4_midchain_idx;
+         return 1;
+       case BFD_TRANSPORT_UDP6:
+         *next_node = bfd_udp_main.ip6_midchain_idx;
+         return 1;
+       }
+      break;
     default:
       /* drop */
       break;
@@ -448,7 +474,7 @@ bfd_udp_key_init (bfd_udp_key_t * key, u32 sw_if_index,
                  const ip46_address_t * local_addr,
                  const ip46_address_t * peer_addr)
 {
-  memset (key, 0, sizeof (*key));
+  clib_memset (key, 0, sizeof (*key));
   key->sw_if_index = sw_if_index;
   key->local_addr.as_u64[0] = local_addr->as_u64[0];
   key->local_addr.as_u64[1] = local_addr->as_u64[1];
@@ -457,8 +483,8 @@ bfd_udp_key_init (bfd_udp_key_t * key, u32 sw_if_index,
 }
 
 static vnet_api_error_t
-bfd_udp_add_session_internal (bfd_udp_main_t * bum, u32 sw_if_index,
-                             u32 desired_min_tx_usec,
+bfd_udp_add_session_internal (vlib_main_t * vm, bfd_udp_main_t * bum,
+                             u32 sw_if_index, u32 desired_min_tx_usec,
                              u32 required_min_rx_usec, u8 detect_mult,
                              const ip46_address_t * local_addr,
                              const ip46_address_t * peer_addr,
@@ -473,11 +499,10 @@ bfd_udp_add_session_internal (bfd_udp_main_t * bum, u32 sw_if_index,
   bfd_session_t *bs = bfd_get_session (bum->bfd_main, t);
   if (!bs)
     {
-      bfd_put_session (bum->bfd_main, bs);
       return VNET_API_ERROR_BFD_EAGAIN;
     }
   bfd_udp_session_t *bus = &bs->udp;
-  memset (bus, 0, sizeof (*bus));
+  clib_memset (bus, 0, sizeof (*bus));
   bfd_udp_key_t *key = &bus->key;
   bfd_udp_key_init (key, sw_if_index, local_addr, peer_addr);
   const bfd_session_t *tmp = bfd_lookup_session (bum, key);
@@ -504,6 +529,14 @@ bfd_udp_add_session_internal (bfd_udp_main_t * bum, u32 sw_if_index,
       BFD_DBG ("adj_nbr_add_or_lock(FIB_PROTOCOL_IP4, VNET_LINK_IP4, %U, %d) "
               "returns %d", format_ip46_address, &key->peer_addr,
               IP46_TYPE_ANY, key->sw_if_index, bus->adj_index);
+      ++bum->udp4_sessions_count;
+      if (1 == bum->udp4_sessions_count)
+       {
+         udp_register_dst_port (vm, UDP_DST_PORT_bfd4,
+                                bfd_udp4_input_node.index, 1);
+         udp_register_dst_port (vm, UDP_DST_PORT_bfd_echo4,
+                                bfd_udp_echo4_input_node.index, 1);
+       }
     }
   else
     {
@@ -513,6 +546,14 @@ bfd_udp_add_session_internal (bfd_udp_main_t * bum, u32 sw_if_index,
       BFD_DBG ("adj_nbr_add_or_lock(FIB_PROTOCOL_IP6, VNET_LINK_IP6, %U, %d) "
               "returns %d", format_ip46_address, &key->peer_addr,
               IP46_TYPE_ANY, key->sw_if_index, bus->adj_index);
+      ++bum->udp6_sessions_count;
+      if (1 == bum->udp6_sessions_count)
+       {
+         udp_register_dst_port (vm, UDP_DST_PORT_bfd6,
+                                bfd_udp6_input_node.index, 0);
+         udp_register_dst_port (vm, UDP_DST_PORT_bfd_echo6,
+                                bfd_udp_echo6_input_node.index, 0);
+       }
     }
   *bs_out = bs;
   return bfd_session_set_params (bum->bfd_main, bs, desired_min_tx_usec,
@@ -526,7 +567,7 @@ bfd_udp_validate_api_input (u32 sw_if_index,
 {
   bfd_udp_main_t *bum = &bfd_udp_main;
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main, sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main, sw_if_index);
   u8 local_ip_valid = 0;
   ip_interface_address_t *ia = NULL;
   if (!sw_if)
@@ -568,28 +609,42 @@ bfd_udp_validate_api_input (u32 sw_if_index,
                        "IP family mismatch (local is ipv6, peer is ipv4)");
          return VNET_API_ERROR_INVALID_ARGUMENT;
        }
-      ip6_main_t *im = &ip6_main;
-      /* *INDENT-OFF* */
-      foreach_ip_interface_address (
-          &im->lookup_main, ia, sw_if_index, 0 /* honor unnumbered */, ({
-            ip6_address_t *x =
-                ip_interface_address_get_address (&im->lookup_main, ia);
-            if (local_addr->ip6.as_u64[0] == x->as_u64[0] &&
-                local_addr->ip6.as_u64[1] == x->as_u64[1])
-              {
-                /* valid address for this interface */
-                local_ip_valid = 1;
-                break;
-              }
-          }));
-      /* *INDENT-ON* */
+
+      if (ip6_address_is_link_local_unicast (&local_addr->ip6))
+       {
+         const ip6_address_t *ll_addr;
+         ll_addr = ip6_get_link_local_address (sw_if_index);
+         if (ip6_address_is_equal (ll_addr, &local_addr->ip6))
+           {
+             /* valid address for this interface */
+             local_ip_valid = 1;
+           }
+       }
+      else
+       {
+         ip6_main_t *im = &ip6_main;
+         /* *INDENT-OFF* */
+         foreach_ip_interface_address (
+             &im->lookup_main, ia, sw_if_index, 0 /* honor unnumbered */, ({
+               ip6_address_t *x =
+                   ip_interface_address_get_address (&im->lookup_main, ia);
+               if (local_addr->ip6.as_u64[0] == x->as_u64[0] &&
+                   local_addr->ip6.as_u64[1] == x->as_u64[1])
+                 {
+                   /* valid address for this interface */
+                   local_ip_valid = 1;
+                   break;
+                 }
+             }));
+         /* *INDENT-ON* */
+       }
     }
 
   if (!local_ip_valid)
     {
       vlib_log_err (bum->log_class,
                    "local address %U not found on interface with index %u",
-                   format_ip46_address, IP46_TYPE_ANY, local_addr,
+                   format_ip46_address, local_addr, IP46_TYPE_ANY,
                    sw_if_index);
       return VNET_API_ERROR_ADDRESS_NOT_FOUND_FOR_INTERFACE;
     }
@@ -655,12 +710,31 @@ bfd_api_verify_common (u32 sw_if_index, u32 desired_min_tx_usec,
 }
 
 static void
-bfd_udp_del_session_internal (bfd_session_t * bs)
+bfd_udp_del_session_internal (vlib_main_t * vm, bfd_session_t * bs)
 {
   bfd_udp_main_t *bum = &bfd_udp_main;
   BFD_DBG ("free bfd-udp session, bs_idx=%d", bs->bs_idx);
   mhash_unset (&bum->bfd_session_idx_by_bfd_key, &bs->udp.key, NULL);
   adj_unlock (bs->udp.adj_index);
+  switch (bs->transport)
+    {
+    case BFD_TRANSPORT_UDP4:
+      --bum->udp4_sessions_count;
+      if (!bum->udp4_sessions_count)
+       {
+         udp_unregister_dst_port (vm, UDP_DST_PORT_bfd4, 1);
+         udp_unregister_dst_port (vm, UDP_DST_PORT_bfd_echo4, 1);
+       }
+      break;
+    case BFD_TRANSPORT_UDP6:
+      --bum->udp6_sessions_count;
+      if (!bum->udp6_sessions_count)
+       {
+         udp_unregister_dst_port (vm, UDP_DST_PORT_bfd6, 0);
+         udp_unregister_dst_port (vm, UDP_DST_PORT_bfd_echo6, 0);
+       }
+      break;
+    }
   bfd_put_session (bum->bfd_main, bs);
 }
 
@@ -671,6 +745,9 @@ bfd_udp_add_session (u32 sw_if_index, const ip46_address_t * local_addr,
                     u8 detect_mult, u8 is_authenticated, u32 conf_key_id,
                     u8 bfd_key_id)
 {
+  bfd_main_t *bm = &bfd_main;
+  bfd_lock (bm);
+
   vnet_api_error_t rv =
     bfd_api_verify_common (sw_if_index, desired_min_tx_usec,
                           required_min_rx_usec, detect_mult,
@@ -679,8 +756,8 @@ bfd_udp_add_session (u32 sw_if_index, const ip46_address_t * local_addr,
   if (!rv)
     {
       rv =
-       bfd_udp_add_session_internal (&bfd_udp_main, sw_if_index,
-                                     desired_min_tx_usec,
+       bfd_udp_add_session_internal (vlib_get_main (), &bfd_udp_main,
+                                     sw_if_index, desired_min_tx_usec,
                                      required_min_rx_usec, detect_mult,
                                      local_addr, peer_addr, &bs);
     }
@@ -696,7 +773,7 @@ bfd_udp_add_session (u32 sw_if_index, const ip46_address_t * local_addr,
 #endif
       if (rv)
        {
-         bfd_udp_del_session_internal (bs);
+         bfd_udp_del_session_internal (vlib_get_main (), bs);
        }
     }
   if (!rv)
@@ -704,6 +781,7 @@ bfd_udp_add_session (u32 sw_if_index, const ip46_address_t * local_addr,
       bfd_session_start (bfd_udp_main.bfd_main, bs);
     }
 
+  bfd_unlock (bm);
   return rv;
 }
 
@@ -715,17 +793,23 @@ bfd_udp_mod_session (u32 sw_if_index,
                     u32 required_min_rx_usec, u8 detect_mult)
 {
   bfd_session_t *bs = NULL;
+  bfd_main_t *bm = &bfd_main;
+  vnet_api_error_t error;
+  bfd_lock (bm);
   vnet_api_error_t rv =
     bfd_udp_find_session_by_api_input (sw_if_index, local_addr, peer_addr,
                                       &bs);
   if (rv)
     {
+      bfd_unlock (bm);
       return rv;
     }
 
-  return bfd_session_set_params (bfd_udp_main.bfd_main, bs,
-                                desired_min_tx_usec, required_min_rx_usec,
-                                detect_mult);
+  error = bfd_session_set_params (bfd_udp_main.bfd_main, bs,
+                                 desired_min_tx_usec, required_min_rx_usec,
+                                 detect_mult);
+  bfd_unlock (bm);
+  return error;
 }
 
 vnet_api_error_t
@@ -734,31 +818,39 @@ bfd_udp_del_session (u32 sw_if_index,
                     const ip46_address_t * peer_addr)
 {
   bfd_session_t *bs = NULL;
+  bfd_main_t *bm = &bfd_main;
+  bfd_lock (bm);
   vnet_api_error_t rv =
     bfd_udp_find_session_by_api_input (sw_if_index, local_addr, peer_addr,
                                       &bs);
   if (rv)
     {
+      bfd_unlock (bm);
       return rv;
     }
-  bfd_udp_del_session_internal (bs);
+  bfd_udp_del_session_internal (vlib_get_main (), bs);
+  bfd_unlock (bm);
   return 0;
 }
 
 vnet_api_error_t
-bfd_udp_session_set_flags (u32 sw_if_index,
+bfd_udp_session_set_flags (vlib_main_t * vm, u32 sw_if_index,
                           const ip46_address_t * local_addr,
                           const ip46_address_t * peer_addr, u8 admin_up_down)
 {
   bfd_session_t *bs = NULL;
+  bfd_main_t *bm = &bfd_main;
+  bfd_lock (bm);
   vnet_api_error_t rv =
     bfd_udp_find_session_by_api_input (sw_if_index, local_addr, peer_addr,
                                       &bs);
   if (rv)
     {
+      bfd_unlock (bm);
       return rv;
     }
-  bfd_session_set_flags (bs, admin_up_down);
+  bfd_session_set_flags (vm, bs, admin_up_down);
+  bfd_unlock (bm);
   return 0;
 }
 
@@ -768,6 +860,10 @@ bfd_udp_auth_activate (u32 sw_if_index,
                       const ip46_address_t * peer_addr,
                       u32 conf_key_id, u8 key_id, u8 is_delayed)
 {
+  bfd_main_t *bm = &bfd_main;
+  bfd_lock (bm);
+  vnet_api_error_t error;
+
 #if WITH_LIBSSL > 0
   bfd_session_t *bs = NULL;
   vnet_api_error_t rv =
@@ -775,12 +871,16 @@ bfd_udp_auth_activate (u32 sw_if_index,
                                       &bs);
   if (rv)
     {
+      bfd_unlock (bm);
       return rv;
     }
-  return bfd_auth_activate (bs, conf_key_id, key_id, is_delayed);
+  error = bfd_auth_activate (bs, conf_key_id, key_id, is_delayed);
+  bfd_unlock (bm);
+  return error;
 #else
   vlib_log_err (bfd_udp_main->log_class,
                "SSL missing, cannot activate BFD authentication");
+  bfd_unlock (bm);
   return VNET_API_ERROR_BFD_NOTSUPP;
 #endif
 }
@@ -790,15 +890,21 @@ bfd_udp_auth_deactivate (u32 sw_if_index,
                         const ip46_address_t * local_addr,
                         const ip46_address_t * peer_addr, u8 is_delayed)
 {
+  bfd_main_t *bm = &bfd_main;
+  vnet_api_error_t error;
+  bfd_lock (bm);
   bfd_session_t *bs = NULL;
   vnet_api_error_t rv =
     bfd_udp_find_session_by_api_input (sw_if_index, local_addr, peer_addr,
                                       &bs);
   if (rv)
     {
+      bfd_unlock (bm);
       return rv;
     }
-  return bfd_auth_deactivate (bs, is_delayed);
+  error = bfd_auth_deactivate (bs, is_delayed);
+  bfd_unlock (bm);
+  return error;
 }
 
 typedef enum
@@ -806,6 +912,7 @@ typedef enum
   BFD_UDP_INPUT_NEXT_NORMAL,
   BFD_UDP_INPUT_NEXT_REPLY_ARP,
   BFD_UDP_INPUT_NEXT_REPLY_REWRITE,
+  BFD_UDP_INPUT_NEXT_REPLY_MIDCHAIN,
   BFD_UDP_INPUT_N_NEXT,
 } bfd_udp_input_next_t;
 
@@ -832,6 +939,14 @@ typedef enum
     BFD_UDP_N_ERROR,
 } bfd_udp_error_t;
 
+typedef enum
+{
+  BFD_UDP_ECHO_INPUT_NEXT_NORMAL,
+  BFD_UDP_ECHO_INPUT_NEXT_REPLY_ARP,
+  BFD_UDP_ECHO_INPUT_NEXT_REPLY_REWRITE,
+  BFD_UDP_ECHO_INPUT_N_NEXT,
+} bfd_udp_echo_input_next_t;
+
 /* Packet counters - BFD ECHO packets */
 #define foreach_bfd_udp_echo_error(F)           \
   F (NONE, "good bfd echo packets (processed)") \
@@ -921,22 +1036,12 @@ typedef struct
 } bfd_rpc_update_t;
 
 static void
-bfd_rpc_update_session_cb (const bfd_rpc_update_t * a)
+bfd_rpc_update_session (vlib_main_t * vm, u32 bs_idx, const bfd_pkt_t * pkt)
 {
-  bfd_consume_pkt (bfd_udp_main.bfd_main, &a->pkt, a->bs_idx);
-}
-
-static void
-bfd_rpc_update_session (u32 bs_idx, const bfd_pkt_t * pkt)
-{
-  /* packet length was already verified to be correct by the caller */
-  const u32 data_size = sizeof (bfd_rpc_update_t) -
-    STRUCT_SIZE_OF (bfd_rpc_update_t, pkt) + pkt->head.length;
-  u8 data[data_size];
-  bfd_rpc_update_t *update = (bfd_rpc_update_t *) data;
-  update->bs_idx = bs_idx;
-  clib_memcpy (&update->pkt, pkt, pkt->head.length);
-  vl_api_rpc_call_main_thread (bfd_rpc_update_session_cb, data, data_size);
+  bfd_main_t *bm = &bfd_main;
+  bfd_lock (bm);
+  bfd_consume_pkt (vm, bm, pkt, bs_idx);
+  bfd_unlock (bm);
 }
 
 static bfd_udp_error_t
@@ -981,7 +1086,7 @@ bfd_udp4_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
   else
     {
       bfd_udp_key_t key;
-      memset (&key, 0, sizeof (key));
+      clib_memset (&key, 0, sizeof (key));
       key.sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
       key.local_addr.ip4.as_u32 = ip4->dst_address.as_u32;
       key.peer_addr.ip4.as_u32 = ip4->src_address.as_u32;
@@ -997,7 +1102,7 @@ bfd_udp4_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
       return BFD_UDP_ERROR_BAD;
     }
   BFD_DBG ("BFD session found, bs_idx=%u", bs->bs_idx);
-  if (!bfd_verify_pkt_auth (pkt, b->current_length, bs))
+  if (!bfd_verify_pkt_auth (vm, pkt, b->current_length, bs))
     {
       BFD_ERR ("Packet verification failed, dropping packet");
       return BFD_UDP_ERROR_BAD;
@@ -1007,7 +1112,7 @@ bfd_udp4_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
     {
       return err;
     }
-  bfd_rpc_update_session (bs->bs_idx, pkt);
+  bfd_rpc_update_session (vm, bs->bs_idx, pkt);
   *bs_out = bs;
   return BFD_UDP_ERROR_NONE;
 }
@@ -1123,7 +1228,7 @@ bfd_udp6_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
   else
     {
       bfd_udp_key_t key;
-      memset (&key, 0, sizeof (key));
+      clib_memset (&key, 0, sizeof (key));
       key.sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
       key.local_addr.ip6.as_u64[0] = ip6->dst_address.as_u64[0];
       key.local_addr.ip6.as_u64[1] = ip6->dst_address.as_u64[1];
@@ -1141,7 +1246,7 @@ bfd_udp6_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
       return BFD_UDP_ERROR_BAD;
     }
   BFD_DBG ("BFD session found, bs_idx=%u", bs->bs_idx);
-  if (!bfd_verify_pkt_auth (pkt, b->current_length, bs))
+  if (!bfd_verify_pkt_auth (vm, pkt, b->current_length, bs))
     {
       BFD_ERR ("Packet verification failed, dropping packet");
       return BFD_UDP_ERROR_BAD;
@@ -1151,7 +1256,7 @@ bfd_udp6_scan (vlib_main_t * vm, vlib_node_runtime_t * rt,
     {
       return err;
     }
-  bfd_rpc_update_session (bs->bs_idx, pkt);
+  bfd_rpc_update_session (vm, bs->bs_idx, pkt);
   *bs_out = bs;
   return BFD_UDP_ERROR_NONE;
 }
@@ -1166,6 +1271,7 @@ bfd_udp_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
 {
   u32 n_left_from, *from;
   bfd_input_trace_t *t0;
+  bfd_main_t *bm = &bfd_main;
 
   from = vlib_frame_vector_args (f);   /* array of buffer indices */
   n_left_from = f->n_vectors;  /* number of buffer indices */
@@ -1189,10 +1295,11 @@ bfd_udp_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
          len = (b0->current_length < sizeof (t0->data)) ? b0->current_length
            : sizeof (t0->data);
          t0->len = len;
-         clib_memcpy (t0->data, vlib_buffer_get_current (b0), len);
+         clib_memcpy_fast (t0->data, vlib_buffer_get_current (b0), len);
        }
 
       /* scan this bfd pkt. error0 is the counter index to bmp */
+      bfd_lock (bm);
       if (is_ipv6)
        {
          error0 = bfd_udp6_scan (vm, rt, b0, &bs);
@@ -1216,7 +1323,6 @@ bfd_udp_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
            {
              b0->current_data = 0;
              b0->current_length = 0;
-             memset (vnet_buffer (b0), 0, sizeof (*vnet_buffer (b0)));
              bfd_init_final_control_frame (vm, b0, bfd_udp_main.bfd_main, bs,
                                            0);
              if (is_ipv6)
@@ -1239,12 +1345,16 @@ bfd_udp_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
                case IP_LOOKUP_NEXT_REWRITE:
                  next0 = BFD_UDP_INPUT_NEXT_REPLY_REWRITE;
                  break;
+               case IP_LOOKUP_NEXT_MIDCHAIN:
+                 next0 = BFD_UDP_INPUT_NEXT_REPLY_MIDCHAIN;
+                 break;
                default:
                  /* drop */
                  break;
                }
            }
        }
+      bfd_unlock (bm);
       vlib_set_next_frame_buffer (vm, rt, next0, bi0);
 
       from += 1;
@@ -1281,6 +1391,7 @@ VLIB_REGISTER_NODE (bfd_udp4_input_node, static) = {
               [BFD_UDP_INPUT_NEXT_NORMAL] = "error-drop",
               [BFD_UDP_INPUT_NEXT_REPLY_ARP] = "ip4-arp",
               [BFD_UDP_INPUT_NEXT_REPLY_REWRITE] = "ip4-lookup",
+              [BFD_UDP_INPUT_NEXT_REPLY_MIDCHAIN] = "ip4-midchain",
       },
 };
 /* *INDENT-ON* */
@@ -1309,6 +1420,7 @@ VLIB_REGISTER_NODE (bfd_udp6_input_node, static) = {
               [BFD_UDP_INPUT_NEXT_NORMAL] = "error-drop",
               [BFD_UDP_INPUT_NEXT_REPLY_ARP] = "ip6-discover-neighbor",
               [BFD_UDP_INPUT_NEXT_REPLY_REWRITE] = "ip6-lookup",
+              [BFD_UDP_INPUT_NEXT_REPLY_MIDCHAIN] = "ip6-midchain",
       },
 };
 /* *INDENT-ON* */
@@ -1323,6 +1435,7 @@ bfd_udp_echo_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
 {
   u32 n_left_from, *from;
   bfd_input_trace_t *t0;
+  bfd_main_t *bm = &bfd_main;
 
   from = vlib_frame_vector_args (f);   /* array of buffer indices */
   n_left_from = f->n_vectors;  /* number of buffer indices */
@@ -1344,13 +1457,14 @@ bfd_udp_echo_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
          len = (b0->current_length < sizeof (t0->data)) ? b0->current_length
            : sizeof (t0->data);
          t0->len = len;
-         clib_memcpy (t0->data, vlib_buffer_get_current (b0), len);
+         clib_memcpy_fast (t0->data, vlib_buffer_get_current (b0), len);
        }
 
-      if (bfd_consume_echo_pkt (bfd_udp_main.bfd_main, b0))
+      bfd_lock (bm);
+      if (bfd_consume_echo_pkt (vm, bfd_udp_main.bfd_main, b0))
        {
          b0->error = rt->errors[BFD_UDP_ERROR_NONE];
-         next0 = BFD_UDP_INPUT_NEXT_NORMAL;
+         next0 = BFD_UDP_ECHO_INPUT_NEXT_NORMAL;
        }
       else
        {
@@ -1366,9 +1480,10 @@ bfd_udp_echo_input (vlib_main_t * vm, vlib_node_runtime_t * rt,
              vlib_node_increment_counter (vm, bfd_udp_echo4_input_node.index,
                                           b0->error, 1);
            }
-         next0 = BFD_UDP_INPUT_NEXT_REPLY_REWRITE;
+         next0 = BFD_UDP_ECHO_INPUT_NEXT_REPLY_REWRITE;
        }
 
+      bfd_unlock (bm);
       vlib_set_next_frame_buffer (vm, rt, next0, bi0);
 
       from += 1;
@@ -1416,12 +1531,12 @@ VLIB_REGISTER_NODE (bfd_udp_echo4_input_node, static) = {
 
   .format_trace = bfd_echo_input_format_trace,
 
-  .n_next_nodes = BFD_UDP_INPUT_N_NEXT,
+  .n_next_nodes = BFD_UDP_ECHO_INPUT_N_NEXT,
   .next_nodes =
       {
-              [BFD_UDP_INPUT_NEXT_NORMAL] = "error-drop",
-              [BFD_UDP_INPUT_NEXT_REPLY_ARP] = "ip4-arp",
-              [BFD_UDP_INPUT_NEXT_REPLY_REWRITE] = "ip4-lookup",
+              [BFD_UDP_ECHO_INPUT_NEXT_NORMAL] = "error-drop",
+              [BFD_UDP_ECHO_INPUT_NEXT_REPLY_ARP] = "ip4-arp",
+              [BFD_UDP_ECHO_INPUT_NEXT_REPLY_REWRITE] = "ip4-lookup",
       },
 };
 /* *INDENT-ON* */
@@ -1445,12 +1560,12 @@ VLIB_REGISTER_NODE (bfd_udp_echo6_input_node, static) = {
 
   .format_trace = bfd_echo_input_format_trace,
 
-  .n_next_nodes = BFD_UDP_INPUT_N_NEXT,
+  .n_next_nodes = BFD_UDP_ECHO_INPUT_N_NEXT,
   .next_nodes =
       {
-              [BFD_UDP_INPUT_NEXT_NORMAL] = "error-drop",
-              [BFD_UDP_INPUT_NEXT_REPLY_ARP] = "ip6-discover-neighbor",
-              [BFD_UDP_INPUT_NEXT_REPLY_REWRITE] = "ip6-lookup",
+              [BFD_UDP_ECHO_INPUT_NEXT_NORMAL] = "error-drop",
+              [BFD_UDP_ECHO_INPUT_NEXT_REPLY_ARP] = "ip6-discover-neighbor",
+              [BFD_UDP_ECHO_INPUT_NEXT_REPLY_REWRITE] = "ip6-lookup",
       },
 };
 
@@ -1484,8 +1599,8 @@ bfd_udp_sw_if_add_del (vnet_main_t * vnm, u32 sw_if_index, u32 is_create)
     vlib_log_notice (bum->log_class,
                     "removal of sw_if_index=%u forces removal of bfd session "
                     "with bs_idx=%u", sw_if_index, (*bs)->bs_idx);
-    bfd_session_set_flags (*bs, 0);
-    bfd_udp_del_session_internal (*bs);
+    bfd_session_set_flags (vlib_get_main (), *bs, 0);
+    bfd_udp_del_session_internal (vlib_get_main (), *bs);
   }
   return 0;
 }
@@ -1498,16 +1613,12 @@ VNET_SW_INTERFACE_ADD_DEL_FUNCTION (bfd_udp_sw_if_add_del);
 static clib_error_t *
 bfd_udp_init (vlib_main_t * vm)
 {
+  bfd_udp_main.udp4_sessions_count = 0;
+  bfd_udp_main.udp6_sessions_count = 0;
   mhash_init (&bfd_udp_main.bfd_session_idx_by_bfd_key, sizeof (uword),
              sizeof (bfd_udp_key_t));
   bfd_udp_main.bfd_main = &bfd_main;
   bfd_udp_main.vnet_main = vnet_get_main ();
-  udp_register_dst_port (vm, UDP_DST_PORT_bfd4, bfd_udp4_input_node.index, 1);
-  udp_register_dst_port (vm, UDP_DST_PORT_bfd6, bfd_udp6_input_node.index, 0);
-  udp_register_dst_port (vm, UDP_DST_PORT_bfd_echo4,
-                        bfd_udp_echo4_input_node.index, 1);
-  udp_register_dst_port (vm, UDP_DST_PORT_bfd_echo6,
-                        bfd_udp_echo6_input_node.index, 0);
   vlib_node_t *node = vlib_get_node_by_name (vm, (u8 *) "ip4-arp");
   ASSERT (node);
   bfd_udp_main.ip4_arp_idx = node->index;
@@ -1520,6 +1631,12 @@ bfd_udp_init (vlib_main_t * vm)
   node = vlib_get_node_by_name (vm, (u8 *) "ip6-rewrite");
   ASSERT (node);
   bfd_udp_main.ip6_rewrite_idx = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "ip4-midchain");
+  ASSERT (node);
+  bfd_udp_main.ip4_midchain_idx = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "ip6-midchain");
+  ASSERT (node);
+  bfd_udp_main.ip6_midchain_idx = node->index;
 
   bfd_udp_main.log_class = vlib_log_register_class ("bfd", "udp");
   vlib_log_debug (bfd_udp_main.log_class, "initialized");