Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 969 insertions, 0 deletions

diff --git a/src/vnet/bfd/bfd_main.c b/src/vnet/bfd/bfd_main.c
new file mode 100644
index 00000000000..e25eadfc510
--- /dev/null
+++ b/src/vnet/bfd/bfd_main.c
@@ -0,0 +1,969 @@
+/*
+ * Copyright (c) 2011-2016 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.
+ */
+/**
+ * @file
+ * @brief BFD nodes implementation
+ */
+
+#include <vppinfra/random.h>
+#include <vppinfra/error.h>
+#include <vppinfra/hash.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ethernet/packet.h>
+#include <vnet/bfd/bfd_debug.h>
+#include <vnet/bfd/bfd_protocol.h>
+#include <vnet/bfd/bfd_main.h>
+
+static u64
+bfd_us_to_clocks (bfd_main_t * bm, u64 us)
+{
+  return bm->cpu_cps * ((f64) us / USEC_PER_SECOND);
+}
+
+static vlib_node_registration_t bfd_process_node;
+
+typedef enum
+{
+#define F(t, n) BFD_OUTPUT_##t,
+  foreach_bfd_transport (F)
+#undef F
+    BFD_OUTPUT_N_NEXT,
+} bfd_output_next_t;
+
+static u32 bfd_next_index_by_transport[] = {
+#define F(t, n) [BFD_TRANSPORT_##t] = BFD_OUTPUT_##t,
+  foreach_bfd_transport (F)
+#undef F
+};
+
+/*
+ * We actually send all bfd pkts to the "error" node after scanning
+ * them, so the graph node has only one next-index. The "error-drop"
+ * node automatically bumps our per-node packet counters for us.
+ */
+typedef enum
+{
+  BFD_INPUT_NEXT_NORMAL,
+  BFD_INPUT_N_NEXT,
+} bfd_input_next_t;
+
+static void bfd_on_state_change (bfd_main_t * bm, bfd_session_t * bs, u64 now,
+				 int handling_wakeup);
+
+static void
+bfd_set_defaults (bfd_main_t * bm, bfd_session_t * bs)
+{
+  bs->local_state = BFD_STATE_down;
+  bs->local_diag = BFD_DIAG_CODE_no_diag;
+  bs->remote_state = BFD_STATE_down;
+  bs->local_demand = 0;
+  bs->remote_discr = 0;
+  bs->desired_min_tx_us = BFD_DEFAULT_DESIRED_MIN_TX_US;
+  bs->desired_min_tx_clocks = bfd_us_to_clocks (bm, bs->desired_min_tx_us);
+  bs->remote_min_rx_us = 1;
+  bs->remote_demand = 0;
+}
+
+static void
+bfd_set_diag (bfd_session_t * bs, bfd_diag_code_e code)
+{
+  if (bs->local_diag != code)
+    {
+      BFD_DBG ("set local_diag, bs_idx=%d: '%d:%s'", bs->bs_idx, code,
+	       bfd_diag_code_string (code));
+      bs->local_diag = code;
+    }
+}
+
+static void
+bfd_set_state (bfd_main_t * bm, bfd_session_t * bs,
+	       bfd_state_e new_state, int handling_wakeup)
+{
+  if (bs->local_state != new_state)
+    {
+      BFD_DBG ("Change state, bs_idx=%d: %s->%s", bs->bs_idx,
+	       bfd_state_string (bs->local_state),
+	       bfd_state_string (new_state));
+      bs->local_state = new_state;
+      bfd_on_state_change (bm, bs, clib_cpu_time_now (), handling_wakeup);
+    }
+}
+
+static void
+bfd_recalc_tx_interval (bfd_main_t * bm, bfd_session_t * bs)
+{
+  if (!bs->local_demand)
+    {
+      bs->transmit_interval_clocks =
+	clib_max (bs->desired_min_tx_clocks, bs->remote_min_rx_clocks);
+    }
+  else
+    {
+      /* TODO */
+    }
+  BFD_DBG ("Recalculated transmit interval %lu clocks/%.2fs",
+	   bs->transmit_interval_clocks,
+	   bs->transmit_interval_clocks / bm->cpu_cps);
+}
+
+static void
+bfd_calc_next_tx (bfd_main_t * bm, bfd_session_t * bs, u64 now)
+{
+  if (!bs->local_demand)
+    {
+      if (bs->local_detect_mult > 1)
+	{
+	  /* common case - 75-100% of transmit interval */
+	  bs->tx_timeout_clocks = now +
+	    (1 - .25 * (random_f64 (&bm->random_seed))) *
+	    bs->transmit_interval_clocks;
+	  if (bs->tx_timeout_clocks < now)
+	    {
+	      /* huh, we've missed it already, skip the missed events */
+	      const u64 missed =
+		(now - bs->tx_timeout_clocks) / bs->transmit_interval_clocks;
+	      BFD_ERR ("Missed %lu transmit events (now is %lu, calc "
+		       "tx_timeout is %lu)!",
+		       missed, now, bs->tx_timeout_clocks);
+	      bs->tx_timeout_clocks +=
+		(missed + 1) * bs->transmit_interval_clocks;
+	    }
+	}
+      else
+	{
+	  /* special case - 75-90% of transmit interval */
+	  bs->tx_timeout_clocks =
+	    now +
+	    (.9 - .15 * (random_f64 (&bm->random_seed))) *
+	    bs->transmit_interval_clocks;
+	  if (bs->tx_timeout_clocks < now)
+	    {
+	      /* huh, we've missed it already, skip the missed events */
+	      const u64 missed =
+		(now - bs->tx_timeout_clocks) / bs->transmit_interval_clocks;
+	      BFD_ERR ("Missed %lu transmit events (now is %lu, calc "
+		       "tx_timeout is %lu)!",
+		       missed, now, bs->tx_timeout_clocks);
+	      bs->tx_timeout_clocks +=
+		(missed + 1) * bs->transmit_interval_clocks;
+	    }
+	}
+    }
+  else
+    {
+      /* TODO */
+    }
+  if (bs->tx_timeout_clocks)
+    {
+      BFD_DBG ("Next transmit in %lu clocks/%.02fs@%lu",
+	       bs->tx_timeout_clocks - now,
+	       (bs->tx_timeout_clocks - now) / bm->cpu_cps,
+	       bs->tx_timeout_clocks);
+    }
+}
+
+static void
+bfd_recalc_detection_time (bfd_main_t * bm, bfd_session_t * bs)
+{
+  if (!bs->local_demand)
+    {
+      bs->detection_time_clocks =
+	bs->remote_detect_mult *
+	bfd_us_to_clocks (bm, clib_max (bs->required_min_rx_us,
+					bs->remote_desired_min_tx_us));
+    }
+  else
+    {
+      bs->detection_time_clocks =
+	bs->local_detect_mult *
+	bfd_us_to_clocks (bm,
+			  clib_max (bs->desired_min_tx_us,
+				    bs->remote_min_rx_us));
+    }
+  BFD_DBG ("Recalculated detection time %lu clocks/%.2fs",
+	   bs->detection_time_clocks,
+	   bs->detection_time_clocks / bm->cpu_cps);
+}
+
+static void
+bfd_set_timer (bfd_main_t * bm, bfd_session_t * bs, u64 now,
+	       int handling_wakeup)
+{
+  u64 next = 0;
+  u64 rx_timeout = 0;
+  if (BFD_STATE_up == bs->local_state)
+    {
+      rx_timeout = bs->last_rx_clocks + bs->detection_time_clocks;
+    }
+  if (bs->tx_timeout_clocks && rx_timeout)
+    {
+      next = clib_min (bs->tx_timeout_clocks, rx_timeout);
+    }
+  else if (bs->tx_timeout_clocks)
+    {
+      next = bs->tx_timeout_clocks;
+    }
+  else if (rx_timeout)
+    {
+      next = rx_timeout;
+    }
+  BFD_DBG ("bs_idx=%u, tx_timeout=%lu, rx_timeout=%lu, next=%s", bs->bs_idx,
+	   bs->tx_timeout_clocks, rx_timeout,
+	   next == bs->tx_timeout_clocks ? "tx" : "rx");
+  /* sometimes the wheel expires an event a bit sooner than requested, account
+     for that here */
+  if (next && (now + bm->wheel_inaccuracy > bs->wheel_time_clocks ||
+	       next < bs->wheel_time_clocks || !bs->wheel_time_clocks))
+    {
+      bs->wheel_time_clocks = next;
+      BFD_DBG ("timing_wheel_insert(%p, %lu (%ld clocks/%.2fs in the "
+	       "future), %u);",
+	       &bm->wheel, bs->wheel_time_clocks,
+	       (i64) bs->wheel_time_clocks - clib_cpu_time_now (),
+	       (i64) (bs->wheel_time_clocks - clib_cpu_time_now ()) /
+	       bm->cpu_cps, bs->bs_idx);
+      timing_wheel_insert (&bm->wheel, bs->wheel_time_clocks, bs->bs_idx);
+      if (!handling_wakeup)
+	{
+	  vlib_process_signal_event (bm->vlib_main,
+				     bm->bfd_process_node_index,
+				     BFD_EVENT_RESCHEDULE, bs->bs_idx);
+	}
+    }
+}
+
+static void
+bfd_set_desired_min_tx (bfd_main_t * bm, bfd_session_t * bs, u64 now,
+			u32 desired_min_tx_us, int handling_wakeup)
+{
+  bs->desired_min_tx_us = desired_min_tx_us;
+  bs->desired_min_tx_clocks = bfd_us_to_clocks (bm, bs->desired_min_tx_us);
+  BFD_DBG ("Set desired min tx to %uus/%lu clocks/%.2fs",
+	   bs->desired_min_tx_us, bs->desired_min_tx_clocks,
+	   bs->desired_min_tx_clocks / bm->cpu_cps);
+  bfd_recalc_detection_time (bm, bs);
+  bfd_recalc_tx_interval (bm, bs);
+  bfd_calc_next_tx (bm, bs, now);
+  bfd_set_timer (bm, bs, now, handling_wakeup);
+}
+
+static void
+bfd_set_remote_required_min_rx (bfd_main_t * bm, bfd_session_t * bs,
+				u64 now,
+				u32 remote_required_min_rx_us,
+				int handling_wakeup)
+{
+  bs->remote_min_rx_us = remote_required_min_rx_us;
+  bs->remote_min_rx_clocks = bfd_us_to_clocks (bm, bs->remote_min_rx_us);
+  BFD_DBG ("Set remote min rx to %uus/%lu clocks/%.2fs", bs->remote_min_rx_us,
+	   bs->remote_min_rx_clocks, bs->remote_min_rx_clocks / bm->cpu_cps);
+  bfd_recalc_detection_time (bm, bs);
+  bfd_recalc_tx_interval (bm, bs);
+  bfd_calc_next_tx (bm, bs, now);
+  bfd_set_timer (bm, bs, now, handling_wakeup);
+}
+
+void
+bfd_session_start (bfd_main_t * bm, bfd_session_t * bs)
+{
+  BFD_DBG ("%U", format_bfd_session, bs);
+  bfd_recalc_tx_interval (bm, bs);
+  vlib_process_signal_event (bm->vlib_main, bm->bfd_process_node_index,
+			     BFD_EVENT_NEW_SESSION, bs->bs_idx);
+}
+
+vnet_api_error_t
+bfd_del_session (uword bs_idx)
+{
+  const bfd_main_t *bm = &bfd_main;
+  if (!pool_is_free_index (bm->sessions, bs_idx))
+    {
+      bfd_session_t *bs = pool_elt_at_index (bm->sessions, bs_idx);
+      pool_put (bm->sessions, bs);
+      return 0;
+    }
+  else
+    {
+      BFD_ERR ("no such session");
+      return VNET_API_ERROR_BFD_NOENT;
+    }
+  return 0;
+}
+
+const char *
+bfd_diag_code_string (bfd_diag_code_e diag)
+{
+#define F(n, t, s)             \
+  case BFD_DIAG_CODE_NAME (t): \
+    return s;
+  switch (diag)
+    {
+    foreach_bfd_diag_code (F)}
+  return "UNKNOWN";
+#undef F
+}
+
+const char *
+bfd_state_string (bfd_state_e state)
+{
+#define F(n, t, s)         \
+  case BFD_STATE_NAME (t): \
+    return s;
+  switch (state)
+    {
+    foreach_bfd_state (F)}
+  return "UNKNOWN";
+#undef F
+}
+
+vnet_api_error_t
+bfd_session_set_flags (u32 bs_idx, u8 admin_up_down)
+{
+  bfd_main_t *bm = &bfd_main;
+  if (pool_is_free_index (bm->sessions, bs_idx))
+    {
+      BFD_ERR ("invalid bs_idx=%u", bs_idx);
+      return VNET_API_ERROR_BFD_NOENT;
+    }
+  bfd_session_t *bs = pool_elt_at_index (bm->sessions, bs_idx);
+  if (admin_up_down)
+    {
+      bfd_set_state (bm, bs, BFD_STATE_down, 0);
+    }
+  else
+    {
+      bfd_set_diag (bs, BFD_DIAG_CODE_neighbor_sig_down);
+      bfd_set_state (bm, bs, BFD_STATE_admin_down, 0);
+    }
+  return 0;
+}
+
+u8 *
+bfd_input_format_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 *);
+  const bfd_input_trace_t *t = va_arg (*args, bfd_input_trace_t *);
+  const bfd_pkt_t *pkt = (bfd_pkt_t *) t->data;
+  if (t->len > STRUCT_SIZE_OF (bfd_pkt_t, head))
+    {
+      s = format (s, "BFD v%u, diag=%u(%s), state=%u(%s),\n"
+		  "    flags=(P:%u, F:%u, C:%u, A:%u, D:%u, M:%u), detect_mult=%u, "
+		  "length=%u\n",
+		  bfd_pkt_get_version (pkt), bfd_pkt_get_diag_code (pkt),
+		  bfd_diag_code_string (bfd_pkt_get_diag_code (pkt)),
+		  bfd_pkt_get_state (pkt),
+		  bfd_state_string (bfd_pkt_get_state (pkt)),
+		  bfd_pkt_get_poll (pkt), bfd_pkt_get_final (pkt),
+		  bfd_pkt_get_control_plane_independent (pkt),
+		  bfd_pkt_get_auth_present (pkt), bfd_pkt_get_demand (pkt),
+		  bfd_pkt_get_multipoint (pkt), pkt->head.detect_mult,
+		  pkt->head.length);
+      if (t->len >= sizeof (bfd_pkt_t)
+	  && pkt->head.length >= sizeof (bfd_pkt_t))
+	{
+	  s = format (s, "    my discriminator: %u\n", pkt->my_disc);
+	  s = format (s, "    your discriminator: %u\n", pkt->your_disc);
+	  s = format (s, "    desired min tx interval: %u\n",
+		      clib_net_to_host_u32 (pkt->des_min_tx));
+	  s = format (s, "    required min rx interval: %u\n",
+		      clib_net_to_host_u32 (pkt->req_min_rx));
+	  s = format (s, "    required min echo rx interval: %u\n",
+		      clib_net_to_host_u32 (pkt->req_min_echo_rx));
+	}
+    }
+
+  return s;
+}
+
+static void
+bfd_on_state_change (bfd_main_t * bm, bfd_session_t * bs, u64 now,
+		     int handling_wakeup)
+{
+  BFD_DBG ("State changed: %U", format_bfd_session, bs);
+  bfd_event (bm, bs);
+  switch (bs->local_state)
+    {
+    case BFD_STATE_admin_down:
+      bfd_set_desired_min_tx (bm, bs, now,
+			      clib_max (bs->config_desired_min_tx_us,
+					BFD_DEFAULT_DESIRED_MIN_TX_US),
+			      handling_wakeup);
+      break;
+    case BFD_STATE_down:
+      bfd_set_desired_min_tx (bm, bs, now,
+			      clib_max (bs->config_desired_min_tx_us,
+					BFD_DEFAULT_DESIRED_MIN_TX_US),
+			      handling_wakeup);
+      break;
+    case BFD_STATE_init:
+      bfd_set_desired_min_tx (bm, bs, now,
+			      clib_max (bs->config_desired_min_tx_us,
+					BFD_DEFAULT_DESIRED_MIN_TX_US),
+			      handling_wakeup);
+      break;
+    case BFD_STATE_up:
+      bfd_set_desired_min_tx (bm, bs, now, bs->config_desired_min_tx_us,
+			      handling_wakeup);
+      break;
+    }
+}
+
+static void
+bfd_add_transport_layer (vlib_main_t * vm, vlib_buffer_t * b,
+			 bfd_session_t * bs)
+{
+  switch (bs->transport)
+    {
+    case BFD_TRANSPORT_UDP4:
+      /* fallthrough */
+    case BFD_TRANSPORT_UDP6:
+      BFD_DBG ("Transport bfd via udp, bs_idx=%u", bs->bs_idx);
+      bfd_add_udp_transport (vm, b, &bs->udp);
+      break;
+    }
+}
+
+static vlib_buffer_t *
+bfd_create_frame (vlib_main_t * vm, vlib_node_runtime_t * rt,
+		  bfd_session_t * bs)
+{
+  u32 bi;
+  if (vlib_buffer_alloc (vm, &bi, 1) != 1)
+    {
+      clib_warning ("buffer allocation failure");
+      return NULL;
+    }
+
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  ASSERT (b->current_data == 0);
+
+  u32 *to_next;
+  u32 n_left_to_next;
+
+  vlib_get_next_frame (vm, rt, bfd_next_index_by_transport[bs->transport],
+		       to_next, n_left_to_next);
+
+  to_next[0] = bi;
+  n_left_to_next -= 1;
+
+  vlib_put_next_frame (vm, rt, bfd_next_index_by_transport[bs->transport],
+		       n_left_to_next);
+  return b;
+}
+
+static void
+bfd_init_control_frame (vlib_buffer_t * b, bfd_session_t * bs)
+{
+  bfd_pkt_t *pkt = vlib_buffer_get_current (b);
+  const u32 bfd_length = 24;
+  memset (pkt, 0, sizeof (*pkt));
+
+  bfd_pkt_set_version (pkt, 1);
+  bfd_pkt_set_diag_code (pkt, bs->local_diag);
+  bfd_pkt_set_state (pkt, bs->local_state);
+  if (bs->local_demand && BFD_STATE_up == bs->local_state &&
+      BFD_STATE_up == bs->remote_state)
+    {
+      bfd_pkt_set_demand (pkt);
+    }
+  pkt->head.detect_mult = bs->local_detect_mult;
+  pkt->head.length = clib_host_to_net_u32 (bfd_length);
+  pkt->my_disc = bs->local_discr;
+  pkt->your_disc = bs->remote_discr;
+  pkt->des_min_tx = clib_host_to_net_u32 (bs->desired_min_tx_us);
+  pkt->req_min_rx = clib_host_to_net_u32 (bs->required_min_rx_us);
+  pkt->req_min_echo_rx = clib_host_to_net_u32 (0);	/* FIXME */
+  b->current_length = bfd_length;
+}
+
+static void
+bfd_send_periodic (vlib_main_t * vm, vlib_node_runtime_t * rt,
+		   bfd_main_t * bm, bfd_session_t * bs, u64 now,
+		   int handling_wakeup)
+{
+  if (!bs->remote_min_rx_us)
+    {
+      BFD_DBG
+	("bfd.RemoteMinRxInterval is zero, not sending periodic control "
+	 "frame");
+      return;
+    }
+  /* FIXME
+     A system MUST NOT periodically transmit BFD Control packets if Demand
+     mode is active on the remote system (bfd.RemoteDemandMode is 1,
+     bfd.SessionState is Up, and bfd.RemoteSessionState is Up) and a Poll
+     Sequence is not being transmitted.
+   */
+  /* sometimes the wheel expires an event a bit sooner than requested, account
+     for that here */
+  if (now + bm->wheel_inaccuracy >= bs->tx_timeout_clocks)
+    {
+      BFD_DBG ("Send periodic control frame for bs_idx=%lu", bs->bs_idx);
+      vlib_buffer_t *b = bfd_create_frame (vm, rt, bs);
+      if (!b)
+	{
+	  return;
+	}
+      bfd_init_control_frame (b, bs);
+      bfd_add_transport_layer (vm, b, bs);
+      bfd_calc_next_tx (bm, bs, now);
+    }
+  else
+    {
+      BFD_DBG
+	("No need to send control frame now, now is %lu, tx_timeout is %lu",
+	 now, bs->tx_timeout_clocks);
+    }
+  bfd_set_timer (bm, bs, now, handling_wakeup);
+}
+
+void
+bfd_send_final (vlib_main_t * vm, vlib_buffer_t * b, bfd_session_t * bs)
+{
+  BFD_DBG ("Send final control frame for bs_idx=%lu", bs->bs_idx);
+  bfd_init_control_frame (b, bs);
+  bfd_pkt_set_final (vlib_buffer_get_current (b));
+  bfd_add_transport_layer (vm, b, bs);
+}
+
+static void
+bfd_check_rx_timeout (bfd_main_t * bm, bfd_session_t * bs, u64 now,
+		      int handling_wakeup)
+{
+  /* sometimes the wheel expires an event a bit sooner than requested, account
+     for that here */
+  if (bs->last_rx_clocks + bs->detection_time_clocks <=
+      now + bm->wheel_inaccuracy)
+    {
+      BFD_DBG ("Rx timeout, session goes down");
+      bfd_set_diag (bs, BFD_DIAG_CODE_det_time_exp);
+      bfd_set_state (bm, bs, BFD_STATE_down, handling_wakeup);
+    }
+}
+
+void
+bfd_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * rt, bfd_main_t * bm,
+		bfd_session_t * bs, u64 now)
+{
+  BFD_DBG ("Timeout for bs_idx=%lu", bs->bs_idx);
+  switch (bs->local_state)
+    {
+    case BFD_STATE_admin_down:
+      BFD_ERR ("Unexpected timeout when in %s state",
+	       bfd_state_string (bs->local_state));
+      abort ();
+      break;
+    case BFD_STATE_down:
+      bfd_send_periodic (vm, rt, bm, bs, now, 1);
+      break;
+    case BFD_STATE_init:
+      BFD_ERR ("Unexpected timeout when in %s state",
+	       bfd_state_string (bs->local_state));
+      abort ();
+      break;
+    case BFD_STATE_up:
+      bfd_check_rx_timeout (bm, bs, now, 1);
+      bfd_send_periodic (vm, rt, bm, bs, now, 1);
+      break;
+    }
+}
+
+/*
+ * bfd process node function
+ */
+static uword
+bfd_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  bfd_main_t *bm = &bfd_main;
+  u32 *expired = 0;
+  uword event_type, *event_data = 0;
+
+  /* So we can send events to the bfd process */
+  bm->bfd_process_node_index = bfd_process_node.index;
+
+  while (1)
+    {
+      u64 now = clib_cpu_time_now ();
+      u64 next_expire = timing_wheel_next_expiring_elt_time (&bm->wheel);
+      BFD_DBG ("timing_wheel_next_expiring_elt_time(%p) returns %lu",
+	       &bm->wheel, next_expire);
+      if ((i64) next_expire < 0)
+	{
+	  BFD_DBG ("wait for event without timeout");
+	  (void) vlib_process_wait_for_event (vm);
+	  event_type = vlib_process_get_events (vm, &event_data);
+	}
+      else
+	{
+	  f64 timeout = ((i64) next_expire - (i64) now) / bm->cpu_cps;
+	  BFD_DBG ("wait for event with timeout %.02f", timeout);
+	  if (timeout < 0)
+	    {
+	      BFD_DBG ("negative timeout, already expired, skipping wait");
+	      event_type = ~0;
+	    }
+	  else
+	    {
+	      (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:		/* no events => timeout */
+	  /* nothing to do here */
+	  break;
+	case BFD_EVENT_RESCHEDULE:
+	  /* nothing to do here - reschedule is done automatically after
+	   * each event or timeout */
+	  break;
+	case BFD_EVENT_NEW_SESSION:
+	  do
+	    {
+	      bfd_session_t *bs =
+		pool_elt_at_index (bm->sessions, *event_data);
+	      bfd_send_periodic (vm, rt, bm, bs, now, 1);
+	    }
+	  while (0);
+	  break;
+	default:
+	  clib_warning ("BUG: event type 0x%wx", event_type);
+	  break;
+	}
+      BFD_DBG ("advancing wheel, now is %lu", now);
+      BFD_DBG ("timing_wheel_advance (%p, %lu, %p, 0);", &bm->wheel, now,
+	       expired);
+      expired = timing_wheel_advance (&bm->wheel, now, expired, 0);
+      BFD_DBG ("Expired %d elements", vec_len (expired));
+      u32 *p = NULL;
+      vec_foreach (p, expired)
+      {
+	const u32 bs_idx = *p;
+	if (!pool_is_free_index (bm->sessions, bs_idx))
+	  {
+	    bfd_session_t *bs = pool_elt_at_index (bm->sessions, bs_idx);
+	    bfd_on_timeout (vm, rt, bm, bs, now);
+	  }
+      }
+      if (expired)
+	{
+	  _vec_len (expired) = 0;
+	}
+      if (event_data)
+	{
+	  _vec_len (event_data) = 0;
+	}
+    }
+
+  return 0;
+}
+
+/*
+ * bfd process node declaration
+ */
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (bfd_process_node, static) = {
+  .function = bfd_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "bfd-process",
+  .n_next_nodes = BFD_OUTPUT_N_NEXT,
+  .next_nodes =
+      {
+#define F(t, n) [BFD_OUTPUT_##t] = n,
+          foreach_bfd_transport (F)
+#undef F
+      },
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+bfd_sw_interface_up_down (vnet_main_t * vnm, u32 sw_if_index, u32 flags)
+{
+  // bfd_main_t *bm = &bfd_main;
+  // vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  if (!(flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
+    {
+      /* TODO */
+    }
+  return 0;
+}
+
+VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (bfd_sw_interface_up_down);
+
+static clib_error_t *
+bfd_hw_interface_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  // bfd_main_t *bm = &bfd_main;
+  if (flags & VNET_HW_INTERFACE_FLAG_LINK_UP)
+    {
+      /* TODO */
+    }
+  return 0;
+}
+
+VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION (bfd_hw_interface_up_down);
+
+/*
+ * setup function
+ */
+static clib_error_t *
+bfd_main_init (vlib_main_t * vm)
+{
+  bfd_main_t *bm = &bfd_main;
+  bm->random_seed = random_default_seed ();
+  bm->vlib_main = vm;
+  bm->vnet_main = vnet_get_main ();
+  memset (&bm->wheel, 0, sizeof (bm->wheel));
+  bm->cpu_cps = 2590000000;	// vm->clib_time.clocks_per_second;
+  BFD_DBG ("cps is %.2f", bm->cpu_cps);
+  const u64 now = clib_cpu_time_now ();
+  timing_wheel_init (&bm->wheel, now, bm->cpu_cps);
+  bm->wheel_inaccuracy = 2 << bm->wheel.log2_clocks_per_bin;
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (bfd_main_init);
+
+bfd_session_t *
+bfd_get_session (bfd_main_t * bm, bfd_transport_t t)
+{
+  bfd_session_t *result;
+  pool_get (bm->sessions, result);
+  memset (result, 0, sizeof (*result));
+  result->bs_idx = result - bm->sessions;
+  result->transport = t;
+  result->local_discr = random_u32 (&bm->random_seed);
+  bfd_set_defaults (bm, result);
+  hash_set (bm->session_by_disc, result->local_discr, result->bs_idx);
+  return result;
+}
+
+void
+bfd_put_session (bfd_main_t * bm, bfd_session_t * bs)
+{
+  hash_unset (bm->session_by_disc, bs->local_discr);
+  pool_put (bm->sessions, bs);
+}
+
+bfd_session_t *
+bfd_find_session_by_idx (bfd_main_t * bm, uword bs_idx)
+{
+  if (!pool_is_free_index (bm->sessions, bs_idx))
+    {
+      return pool_elt_at_index (bm->sessions, bs_idx);
+    }
+  return NULL;
+}
+
+bfd_session_t *
+bfd_find_session_by_disc (bfd_main_t * bm, u32 disc)
+{
+  uword *p = hash_get (bfd_main.session_by_disc, disc);
+  if (p)
+    {
+      return pool_elt_at_index (bfd_main.sessions, *p);
+    }
+  return NULL;
+}
+
+/**
+ * @brief verify bfd packet - common checks
+ *
+ * @param pkt
+ *
+ * @return 1 if bfd packet is valid
+ */
+int
+bfd_verify_pkt_common (const bfd_pkt_t * pkt)
+{
+  if (1 != bfd_pkt_get_version (pkt))
+    {
+      BFD_ERR ("BFD verification failed - unexpected version: '%d'",
+	       bfd_pkt_get_version (pkt));
+      return 0;
+    }
+  if (pkt->head.length < sizeof (bfd_pkt_t) ||
+      (bfd_pkt_get_auth_present (pkt) &&
+       pkt->head.length < sizeof (bfd_pkt_with_auth_t)))
+    {
+      BFD_ERR ("BFD verification failed - unexpected length: '%d' (auth "
+	       "present: %d)",
+	       pkt->head.length, bfd_pkt_get_auth_present (pkt));
+      return 0;
+    }
+  if (!pkt->head.detect_mult)
+    {
+      BFD_ERR ("BFD verification failed - unexpected detect-mult: '%d'",
+	       pkt->head.detect_mult);
+      return 0;
+    }
+  if (bfd_pkt_get_multipoint (pkt))
+    {
+      BFD_ERR ("BFD verification failed - unexpected multipoint: '%d'",
+	       bfd_pkt_get_multipoint (pkt));
+      return 0;
+    }
+  if (!pkt->my_disc)
+    {
+      BFD_ERR ("BFD verification failed - unexpected my-disc: '%d'",
+	       pkt->my_disc);
+      return 0;
+    }
+  if (!pkt->your_disc)
+    {
+      const u8 pkt_state = bfd_pkt_get_state (pkt);
+      if (pkt_state != BFD_STATE_down && pkt_state != BFD_STATE_admin_down)
+	{
+	  BFD_ERR ("BFD verification failed - unexpected state: '%s' "
+		   "(your-disc is zero)", bfd_state_string (pkt_state));
+	  return 0;
+	}
+    }
+  return 1;
+}
+
+/**
+ * @brief verify bfd packet - authentication
+ *
+ * @param pkt
+ *
+ * @return 1 if bfd packet is valid
+ */
+int
+bfd_verify_pkt_session (const bfd_pkt_t * pkt, u16 pkt_size,
+			const bfd_session_t * bs)
+{
+  const bfd_pkt_with_auth_t *with_auth = (bfd_pkt_with_auth_t *) pkt;
+  if (!bfd_pkt_get_auth_present (pkt))
+    {
+      if (pkt_size > sizeof (*pkt))
+	{
+	  BFD_ERR ("BFD verification failed - unexpected packet size '%d' "
+		   "(auth not present)", pkt_size);
+	  return 0;
+	}
+    }
+  else
+    {
+      if (!with_auth->auth.type)
+	{
+	  BFD_ERR ("BFD verification failed - unexpected auth type: '%d'",
+		   with_auth->auth.type);
+	  return 0;
+	}
+      /* TODO FIXME - implement the actual verification */
+    }
+  return 1;
+}
+
+void
+bfd_consume_pkt (bfd_main_t * bm, const bfd_pkt_t * pkt, u32 bs_idx)
+{
+  bfd_session_t *bs = bfd_find_session_by_idx (bm, bs_idx);
+  if (!bs)
+    {
+      return;
+    }
+  BFD_DBG ("Scanning bfd packet, bs_idx=%d", bs->bs_idx);
+  bs->remote_discr = pkt->my_disc;
+  bs->remote_state = bfd_pkt_get_state (pkt);
+  bs->remote_demand = bfd_pkt_get_demand (pkt);
+  u64 now = clib_cpu_time_now ();
+  bs->last_rx_clocks = now;
+  bs->remote_desired_min_tx_us = clib_net_to_host_u32 (pkt->des_min_tx);
+  bs->remote_detect_mult = pkt->head.detect_mult;
+  bfd_set_remote_required_min_rx (bm, bs, now,
+				  clib_net_to_host_u32 (pkt->req_min_rx), 0);
+  /* FIXME
+     If the Required Min Echo RX Interval field is zero, the
+     transmission of Echo packets, if any, MUST cease.
+
+     If a Poll Sequence is being transmitted by the local system and
+     the Final (F) bit in the received packet is set, the Poll Sequence
+     MUST be terminated.
+   */
+  /* FIXME 6.8.2 */
+  /* FIXME 6.8.4 */
+  if (BFD_STATE_admin_down == bs->local_state)
+    return;
+  if (BFD_STATE_admin_down == bs->remote_state)
+    {
+      bfd_set_diag (bs, BFD_DIAG_CODE_neighbor_sig_down);
+      bfd_set_state (bm, bs, BFD_STATE_down, 0);
+    }
+  else if (BFD_STATE_down == bs->local_state)
+    {
+      if (BFD_STATE_down == bs->remote_state)
+	{
+	  bfd_set_state (bm, bs, BFD_STATE_init, 0);
+	}
+      else if (BFD_STATE_init == bs->remote_state)
+	{
+	  bfd_set_state (bm, bs, BFD_STATE_up, 0);
+	}
+    }
+  else if (BFD_STATE_init == bs->local_state)
+    {
+      if (BFD_STATE_up == bs->remote_state ||
+	  BFD_STATE_init == bs->remote_state)
+	{
+	  bfd_set_state (bm, bs, BFD_STATE_up, 0);
+	}
+    }
+  else				/* BFD_STATE_up == bs->local_state */
+    {
+      if (BFD_STATE_down == bs->remote_state)
+	{
+	  bfd_set_diag (bs, BFD_DIAG_CODE_neighbor_sig_down);
+	  bfd_set_state (bm, bs, BFD_STATE_down, 0);
+	}
+    }
+}
+
+u8 *
+format_bfd_session (u8 * s, va_list * args)
+{
+  const bfd_session_t *bs = va_arg (*args, bfd_session_t *);
+  return format (s, "BFD(%u): bfd.SessionState=%s, "
+		 "bfd.RemoteSessionState=%s, "
+		 "bfd.LocalDiscr=%u, "
+		 "bfd.RemoteDiscr=%u, "
+		 "bfd.LocalDiag=%s, "
+		 "bfd.DesiredMinTxInterval=%u, "
+		 "bfd.RequiredMinRxInterval=%u, "
+		 "bfd.RemoteMinRxInterval=%u, "
+		 "bfd.DemandMode=%s, "
+		 "bfd.RemoteDemandMode=%s, "
+		 "bfd.DetectMult=%u, ",
+		 bs->bs_idx, bfd_state_string (bs->local_state),
+		 bfd_state_string (bs->remote_state), bs->local_discr,
+		 bs->remote_discr, bfd_diag_code_string (bs->local_diag),
+		 bs->desired_min_tx_us, bs->required_min_rx_us,
+		 bs->remote_min_rx_us, (bs->local_demand ? "yes" : "no"),
+		 (bs->remote_demand ? "yes" : "no"), bs->local_detect_mult);
+}
+
+bfd_main_t bfd_main;
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */