text: /*
   * Copyright (c) 2015 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.
   */
  /*
   * main.c: main vector processing loop
   *
   * Copyright (c) 2008 Eliot Dresselhaus
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include <math.h>
  #include <vppinfra/format.h>
  #include <vlib/vlib.h>
  #include <vlib/threads.h>
  #include <vppinfra/tw_timer_1t_3w_1024sl_ov.h>
  
  #include <vlib/unix/unix.h>
  #include <vlib/unix/cj.h>
  
  CJ_GLOBAL_LOG_PROTOTYPE;
  
  /* Actually allocate a few extra slots of vector data to support
     speculative vector enqueues which overflow vector data in next frame. */
  #define VLIB_FRAME_SIZE_ALLOC (VLIB_FRAME_SIZE + 4)
  
  u32 wraps;
  
  always_inline u32
  vlib_frame_bytes (u32 n_scalar_bytes, u32 n_vector_bytes)
  {
    u32 n_bytes;
  
    /* Make room for vlib_frame_t plus scalar arguments. */
    n_bytes = vlib_frame_vector_byte_offset (n_scalar_bytes);
  
    /* Make room for vector arguments.
       Allocate a few extra slots of vector data to support
       speculative vector enqueues which overflow vector data in next frame. */
  #define VLIB_FRAME_SIZE_EXTRA 4
    n_bytes += (VLIB_FRAME_SIZE + VLIB_FRAME_SIZE_EXTRA) * n_vector_bytes;
  
    /* Magic number is first 32bit number after vector data.
       Used to make sure that vector data is never overrun. */
  #define VLIB_FRAME_MAGIC (0xabadc0ed)
    n_bytes += sizeof (u32);
  
    /* Pad to cache line. */
    n_bytes = round_pow2 (n_bytes, CLIB_CACHE_LINE_BYTES);
  
    return n_bytes;
  }
  
  always_inline u32 *
  vlib_frame_find_magic (vlib_frame_t * f, vlib_node_t * node)
  {
    void *p = f;
  
    p += vlib_frame_vector_byte_offset (node->scalar_size);
  
    p += (VLIB_FRAME_SIZE + VLIB_FRAME_SIZE_EXTRA) * node->vector_size;
  
    return p;
  }
  
  static vlib_frame_size_t *
  get_frame_size_info (vlib_node_main_t * nm,
  		     u32 n_scalar_bytes, u32 n_vector_bytes)
  {
    uword key = (n_scalar_bytes << 16) | n_vector_bytes;
    uword *p, i;
  
    p = hash_get (nm->frame_size_hash, key);
    if (p)
      i = p[0];
    else
      {
        i = vec_len (nm->frame_sizes);
        vec_validate (nm->frame_sizes, i);
        hash_set (nm->frame_size_hash, key, i);
      }
  
    return vec_elt_at_index (nm->frame_sizes, i);
  }
  
  static u32
  vlib_frame_alloc_to_node (vlib_main_t * vm, u32 to_node_index,
  			  u32 frame_flags)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_frame_size_t *fs;
    vlib_node_t *to_node;
    vlib_frame_t *f;
    u32 fi, l, n, scalar_size, vector_size;
  
    to_node = vlib_get_node (vm, to_node_index);
  
    scalar_size = to_node->scalar_size;
    vector_size = to_node->vector_size;
  
    fs = get_frame_size_info (nm, scalar_size, vector_size);
    n = vlib_frame_bytes (scalar_size, vector_size);
    if ((l = vec_len (fs->free_frame_indices)) > 0)
      {
        /* Allocate from end of free list. */
        fi = fs->free_frame_indices[l - 1];
        f = vlib_get_frame_no_check (vm, fi);
        _vec_len (fs->free_frame_indices) = l - 1;
      }
    else
      {
        f = clib_mem_alloc_aligned_no_fail (n, VLIB_FRAME_ALIGN);
        fi = vlib_frame_index_no_check (vm, f);
      }
  
    /* Poison frame when debugging. */
    if (CLIB_DEBUG > 0)
      clib_memset (f, 0xfe, n);
  
    /* Insert magic number. */
    {
      u32 *magic;
  
      magic = vlib_frame_find_magic (f, to_node);
      *magic = VLIB_FRAME_MAGIC;
    }
  
    f->frame_flags = VLIB_FRAME_IS_ALLOCATED | frame_flags;
    f->n_vectors = 0;
    f->scalar_size = scalar_size;
    f->vector_size = vector_size;
    f->flags = 0;
  
    fs->n_alloc_frames += 1;
  
    return fi;
  }
  
  /* Allocate a frame for from FROM_NODE to TO_NODE via TO_NEXT_INDEX.
     Returns frame index. */
  static u32
  vlib_frame_alloc (vlib_main_t * vm, vlib_node_runtime_t * from_node_runtime,
  		  u32 to_next_index)
  {
    vlib_node_t *from_node;
  
    from_node = vlib_get_node (vm, from_node_runtime->node_index);
    ASSERT (to_next_index < vec_len (from_node->next_nodes));
  
    return vlib_frame_alloc_to_node (vm, from_node->next_nodes[to_next_index],
  				   /* frame_flags */ 0);
  }
  
  vlib_frame_t *
  vlib_get_frame_to_node (vlib_main_t * vm, u32 to_node_index)
  {
    u32 fi = vlib_frame_alloc_to_node (vm, to_node_index,
  				     /* frame_flags */
  				     VLIB_FRAME_FREE_AFTER_DISPATCH);
    return vlib_get_frame (vm, fi);
  }
  
  void
  vlib_put_frame_to_node (vlib_main_t * vm, u32 to_node_index, vlib_frame_t * f)
  {
    vlib_pending_frame_t *p;
    vlib_node_t *to_node;
  
    if (f->n_vectors == 0)
      return;
  
    to_node = vlib_get_node (vm, to_node_index);
  
    vec_add2 (vm->node_main.pending_frames, p, 1);
  
    f->frame_flags |= VLIB_FRAME_PENDING;
    p->frame_index = vlib_frame_index (vm, f);
    p->node_runtime_index = to_node->runtime_index;
    p->next_frame_index = VLIB_PENDING_FRAME_NO_NEXT_FRAME;
  }
  
  /* Free given frame. */
  void
  vlib_frame_free (vlib_main_t * vm, vlib_node_runtime_t * r, vlib_frame_t * f)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_node_t *node;
    vlib_frame_size_t *fs;
    u32 frame_index;
  
    ASSERT (f->frame_flags & VLIB_FRAME_IS_ALLOCATED);
  
    node = vlib_get_node (vm, r->node_index);
    fs = get_frame_size_info (nm, node->scalar_size, node->vector_size);
  
    frame_index = vlib_frame_index (vm, f);
  
    ASSERT (f->frame_flags & VLIB_FRAME_IS_ALLOCATED);
  
    /* No next frames may point to freed frame. */
    if (CLIB_DEBUG > 0)
      {
        vlib_next_frame_t *nf;
        vec_foreach (nf, vm->node_main.next_frames)
  	ASSERT (nf->frame_index != frame_index);
      }
  
    f->frame_flags &= ~VLIB_FRAME_IS_ALLOCATED;
  
    vec_add1 (fs->free_frame_indices, frame_index);
    ASSERT (fs->n_alloc_frames > 0);
    fs->n_alloc_frames -= 1;
  }
  
  static clib_error_t *
  show_frame_stats (vlib_main_t * vm,
  		  unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_frame_size_t *fs;
  
    vlib_cli_output (vm, "%=6s%=12s%=12s", "Size", "# Alloc", "# Free");
    vec_foreach (fs, nm->frame_sizes)
    {
      u32 n_alloc = fs->n_alloc_frames;
      u32 n_free = vec_len (fs->free_frame_indices);
  
      if (n_alloc + n_free > 0)
        vlib_cli_output (vm, "%=6d%=12d%=12d",
  		       fs - nm->frame_sizes, n_alloc, n_free);
    }
  
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (show_frame_stats_cli, static) = {
    .path = "show vlib frame-allocation",
    .short_help = "Show node dispatch frame statistics",
    .function = show_frame_stats,
  };
  /* *INDENT-ON* */
  
  /* Change ownership of enqueue rights to given next node. */
  static void
  vlib_next_frame_change_ownership (vlib_main_t * vm,
  				  vlib_node_runtime_t * node_runtime,
  				  u32 next_index)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_next_frame_t *next_frame;
    vlib_node_t *node, *next_node;
  
    node = vec_elt (nm->nodes, node_runtime->node_index);
  
    /* Only internal & input nodes are allowed to call other nodes. */
    ASSERT (node->type == VLIB_NODE_TYPE_INTERNAL
  	  || node->type == VLIB_NODE_TYPE_INPUT
  	  || node->type == VLIB_NODE_TYPE_PROCESS);
  
    ASSERT (vec_len (node->next_nodes) == node_runtime->n_next_nodes);
  
    next_frame =
      vlib_node_runtime_get_next_frame (vm, node_runtime, next_index);
    next_node = vec_elt (nm->nodes, node->next_nodes[next_index]);
  
    if (next_node->owner_node_index != VLIB_INVALID_NODE_INDEX)
      {
        /* Get frame from previous owner. */
        vlib_next_frame_t *owner_next_frame;
        vlib_next_frame_t tmp;
  
        owner_next_frame =
  	vlib_node_get_next_frame (vm,
  				  next_node->owner_node_index,
  				  next_node->owner_next_index);
  
        /* Swap target next frame with owner's. */
        tmp = owner_next_frame[0];
        owner_next_frame[0] = next_frame[0];
        next_frame[0] = tmp;
  
        /*
         * If next_frame is already pending, we have to track down
         * all pending frames and fix their next_frame_index fields.
         */
        if (next_frame->flags & VLIB_FRAME_PENDING)
  	{
  	  vlib_pending_frame_t *p;
  	  if (next_frame->frame_index != ~0)
  	    {
  	      vec_foreach (p, nm->pending_frames)
  	      {
  		if (p->frame_index == next_frame->frame_index)
  		  {
  		    p->next_frame_index =
  		      next_frame - vm->node_main.next_frames;
  		  }
  	      }
  	    }
  	}
      }
    else
      {
        /* No previous owner. Take ownership. */
        next_frame->flags |= VLIB_FRAME_OWNER;
      }
  
    /* Record new owner. */
    next_node->owner_node_index = node->index;
    next_node->owner_next_index = next_index;
  
    /* Now we should be owner. */
    ASSERT (next_frame->flags & VLIB_FRAME_OWNER);
  }
  
  /* Make sure that magic number is still there.
     Otherwise, it is likely that caller has overrun frame arguments. */
  always_inline void
  validate_frame_magic (vlib_main_t * vm,
  		      vlib_frame_t * f, vlib_node_t * n, uword next_index)
  {
    vlib_node_t *next_node = vlib_get_node (vm, n->next_nodes[next_index]);
    u32 *magic = vlib_frame_find_magic (f, next_node);
    ASSERT (VLIB_FRAME_MAGIC == magic[0]);
  }
  
  vlib_frame_t *
  vlib_get_next_frame_internal (vlib_main_t * vm,
  			      vlib_node_runtime_t * node,
  			      u32 next_index, u32 allocate_new_next_frame)
  {
    vlib_frame_t *f;
    vlib_next_frame_t *nf;
    u32 n_used;
  
    nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
  
    /* Make sure this next frame owns right to enqueue to destination frame. */
    if (PREDICT_FALSE (!(nf->flags & VLIB_FRAME_OWNER)))
      vlib_next_frame_change_ownership (vm, node, next_index);
  
    /* ??? Don't need valid flag: can use frame_index == ~0 */
    if (PREDICT_FALSE (!(nf->flags & VLIB_FRAME_IS_ALLOCATED)))
      {
        nf->frame_index = vlib_frame_alloc (vm, node, next_index);
        nf->flags |= VLIB_FRAME_IS_ALLOCATED;
      }
  
    f = vlib_get_frame (vm, nf->frame_index);
  
    /* Has frame been removed from pending vector (e.g. finished dispatching)?
       If so we can reuse frame. */
    if ((nf->flags & VLIB_FRAME_PENDING)
        && !(f->frame_flags & VLIB_FRAME_PENDING))
      {
        nf->flags &= ~VLIB_FRAME_PENDING;
        f->n_vectors = 0;
        f->flags = 0;
      }
  
    /* Allocate new frame if current one is already full. */
    n_used = f->n_vectors;
    if (n_used >= VLIB_FRAME_SIZE || (allocate_new_next_frame && n_used > 0))
      {
        /* Old frame may need to be freed after dispatch, since we'll have
           two redundant frames from node -> next node. */
        if (!(nf->flags & VLIB_FRAME_NO_FREE_AFTER_DISPATCH))
  	{
  	  vlib_frame_t *f_old = vlib_get_frame (vm, nf->frame_index);
  	  f_old->frame_flags |= VLIB_FRAME_FREE_AFTER_DISPATCH;
  	}
  
        /* Allocate new frame to replace full one. */
        nf->frame_index = vlib_frame_alloc (vm, node, next_index);
        f = vlib_get_frame (vm, nf->frame_index);
        n_used = f->n_vectors;
      }
  
    /* Should have free vectors in frame now. */
    ASSERT (n_used < VLIB_FRAME_SIZE);
  
    if (CLIB_DEBUG > 0)
      {
        validate_frame_magic (vm, f,
  			    vlib_get_node (vm, node->node_index), next_index);
      }
  
    return f;
  }
  
  static void
  vlib_put_next_frame_validate (vlib_main_t * vm,
  			      vlib_node_runtime_t * rt,
  			      u32 next_index, u32 n_vectors_left)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_next_frame_t *nf;
    vlib_frame_t *f;
    vlib_node_runtime_t *next_rt;
    vlib_node_t *next_node;
    u32 n_before, n_after;
  
    nf = vlib_node_runtime_get_next_frame (vm, rt, next_index);
    f = vlib_get_frame (vm, nf->frame_index);
  
    ASSERT (n_vectors_left <= VLIB_FRAME_SIZE);
    n_after = VLIB_FRAME_SIZE - n_vectors_left;
    n_before = f->n_vectors;
  
    ASSERT (n_after >= n_before);
  
    next_rt = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INTERNAL],
  			      nf->node_runtime_index);
    next_node = vlib_get_node (vm, next_rt->node_index);
    if (n_after > 0 && next_node->validate_frame)
      {
        u8 *msg = next_node->validate_frame (vm, rt, f);
        if (msg)
  	{
  	  clib_warning ("%v", msg);
  	  ASSERT (0);
  	}
        vec_free (msg);
      }
  }
  
  void
  vlib_put_next_frame (vlib_main_t * vm,
  		     vlib_node_runtime_t * r,
  		     u32 next_index, u32 n_vectors_left)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_next_frame_t *nf;
    vlib_frame_t *f;
    u32 n_vectors_in_frame;
  
    if (buffer_main.callbacks_registered == 0 && CLIB_DEBUG > 0)
      vlib_put_next_frame_validate (vm, r, next_index, n_vectors_left);
  
    nf = vlib_node_runtime_get_next_frame (vm, r, next_index);
    f = vlib_get_frame (vm, nf->frame_index);
  
    /* Make sure that magic number is still there.  Otherwise, caller
       has overrun frame meta data. */
    if (CLIB_DEBUG > 0)
      {
        vlib_node_t *node = vlib_get_node (vm, r->node_index);
        validate_frame_magic (vm, f, node, next_index);
      }
  
    /* Convert # of vectors left -> number of vectors there. */
    ASSERT (n_vectors_left <= VLIB_FRAME_SIZE);
    n_vectors_in_frame = VLIB_FRAME_SIZE - n_vectors_left;
  
    f->n_vectors = n_vectors_in_frame;
  
    /* If vectors were added to frame, add to pending vector. */
    if (PREDICT_TRUE (n_vectors_in_frame > 0))
      {
        vlib_pending_frame_t *p;
        u32 v0, v1;
  
        r->cached_next_index = next_index;
  
        if (!(f->frame_flags & VLIB_FRAME_PENDING))
  	{
  	  __attribute__ ((unused)) vlib_node_t *node;
  	  vlib_node_t *next_node;
  	  vlib_node_runtime_t *next_runtime;
  
  	  node = vlib_get_node (vm, r->node_index);
  	  next_node = vlib_get_next_node (vm, r->node_index, next_index);
  	  next_runtime = vlib_node_get_runtime (vm, next_node->index);
  
  	  vec_add2 (nm->pending_frames, p, 1);
  
  	  p->frame_index = nf->frame_index;
  	  p->node_runtime_index = nf->node_runtime_index;
  	  p->next_frame_index = nf - nm->next_frames;
  	  nf->flags |= VLIB_FRAME_PENDING;
  	  f->frame_flags |= VLIB_FRAME_PENDING;
  
  	  /*
  	   * If we're going to dispatch this frame on another thread,
  	   * force allocation of a new frame. Otherwise, we create
  	   * a dangling frame reference. Each thread has its own copy of
  	   * the next_frames vector.
  	   */
  	  if (0 && r->thread_index != next_runtime->thread_index)
  	    {
  	      nf->frame_index = ~0;
  	      nf->flags &= ~(VLIB_FRAME_PENDING | VLIB_FRAME_IS_ALLOCATED);
  	    }
  	}
  
        /* Copy trace flag from next_frame and from runtime. */
        nf->flags |=
  	(nf->flags & VLIB_NODE_FLAG_TRACE) | (r->
  					      flags & VLIB_NODE_FLAG_TRACE);
  
        v0 = nf->vectors_since_last_overflow;
        v1 = v0 + n_vectors_in_frame;
        nf->vectors_since_last_overflow = v1;
        if (PREDICT_FALSE (v1 < v0))
  	{
  	  vlib_node_t *node = vlib_get_node (vm, r->node_index);
  	  vec_elt (node->n_vectors_by_next_node, next_index) += v0;
  	}
      }
  }
  
  /* Sync up runtime (32 bit counters) and main node stats (64 bit counters). */
  never_inline void
  vlib_node_runtime_sync_stats (vlib_main_t * vm,
  			      vlib_node_runtime_t * r,
  			      uword n_calls, uword n_vectors, uword n_clocks,
  			      uword n_ticks)
  {
    vlib_node_t *n = vlib_get_node (vm, r->node_index);
  
    n->stats_total.calls += n_calls + r->calls_since_last_overflow;
    n->stats_total.vectors += n_vectors + r->vectors_since_last_overflow;
    n->stats_total.clocks += n_clocks + r->clocks_since_last_overflow;
    n->stats_total.perf_counter_ticks += n_ticks +
      r->perf_counter_ticks_since_last_overflow;
    n->stats_total.perf_counter_vectors += n_vectors +
      r->perf_counter_vectors_since_last_overflow;
    n->stats_total.max_clock = r->max_clock;
    n->stats_total.max_clock_n = r->max_clock_n;
  
    r->calls_since_last_overflow = 0;
    r->vectors_since_last_overflow = 0;
    r->clocks_since_last_overflow = 0;
    r->perf_counter_ticks_since_last_overflow = 0ULL;
    r->perf_counter_vectors_since_last_overflow = 0ULL;
  }
  
  always_inline void __attribute__ ((unused))
  vlib_process_sync_stats (vlib_main_t * vm,
  			 vlib_process_t * p,
  			 uword n_calls, uword n_vectors, uword n_clocks,
  			 uword n_ticks)
  {
    vlib_node_runtime_t *rt = &p->node_runtime;
    vlib_node_t *n = vlib_get_node (vm, rt->node_index);
    vlib_node_runtime_sync_stats (vm, rt, n_calls, n_vectors, n_clocks,
  				n_ticks);
    n->stats_total.suspends += p->n_suspends;
    p->n_suspends = 0;
  }
  
  void
  vlib_node_sync_stats (vlib_main_t * vm, vlib_node_t * n)
  {
    vlib_node_runtime_t *rt;
  
    if (n->type == VLIB_NODE_TYPE_PROCESS)
      {
        /* Nothing to do for PROCESS nodes except in main thread */
        if (vm != &vlib_global_main)
  	return;
  
        vlib_process_t *p = vlib_get_process_from_node (vm, n);
        n->stats_total.suspends += p->n_suspends;
        p->n_suspends = 0;
        rt = &p->node_runtime;
      }
    else
      rt =
        vec_elt_at_index (vm->node_main.nodes_by_type[n->type],
  			n->runtime_index);
  
    vlib_node_runtime_sync_stats (vm, rt, 0, 0, 0, 0);
  
    /* Sync up runtime next frame vector counters with main node structure. */
    {
      vlib_next_frame_t *nf;
      uword i;
      for (i = 0; i < rt->n_next_nodes; i++)
        {
  	nf = vlib_node_runtime_get_next_frame (vm, rt, i);
  	vec_elt (n->n_vectors_by_next_node, i) +=
  	  nf->vectors_since_last_overflow;
  	nf->vectors_since_last_overflow = 0;
        }
    }
  }
  
  always_inline u32
  vlib_node_runtime_update_stats (vlib_main_t * vm,
  				vlib_node_runtime_t * node,
  				uword n_calls,
  				uword n_vectors, uword n_clocks,
  				uword n_ticks)
  {
    u32 ca0, ca1, v0, v1, cl0, cl1, r;
    u32 ptick0, ptick1, pvec0, pvec1;
  
    cl0 = cl1 = node->clocks_since_last_overflow;
    ca0 = ca1 = node->calls_since_last_overflow;
    v0 = v1 = node->vectors_since_last_overflow;
    ptick0 = ptick1 = node->perf_counter_ticks_since_last_overflow;
    pvec0 = pvec1 = node->perf_counter_vectors_since_last_overflow;
  
    ca1 = ca0 + n_calls;
    v1 = v0 + n_vectors;
    cl1 = cl0 + n_clocks;
    ptick1 = ptick0 + n_ticks;
    pvec1 = pvec0 + n_vectors;
  
    node->calls_since_last_overflow = ca1;
    node->clocks_since_last_overflow = cl1;
    node->vectors_since_last_overflow = v1;
    node->perf_counter_ticks_since_last_overflow = ptick1;
    node->perf_counter_vectors_since_last_overflow = pvec1;
  
    node->max_clock_n = node->max_clock > n_clocks ?
      node->max_clock_n : n_vectors;
    node->max_clock = node->max_clock > n_clocks ? node->max_clock : n_clocks;
  
    r = vlib_node_runtime_update_main_loop_vector_stats (vm, node, n_vectors);
  
    if (PREDICT_FALSE (ca1 < ca0 || v1 < v0 || cl1 < cl0) || (ptick1 < ptick0)
        || (pvec1 < pvec0))
      {
        node->calls_since_last_overflow = ca0;
        node->clocks_since_last_overflow = cl0;
        node->vectors_since_last_overflow = v0;
        node->perf_counter_ticks_since_last_overflow = ptick0;
        node->perf_counter_vectors_since_last_overflow = pvec0;
  
        vlib_node_runtime_sync_stats (vm, node, n_calls, n_vectors, n_clocks,
  				    n_ticks);
      }
  
    return r;
  }
  
  static inline u64
  vlib_node_runtime_perf_counter (vlib_main_t * vm)
  {
    if (PREDICT_FALSE (vm->vlib_node_runtime_perf_counter_cb != 0))
      return ((*vm->vlib_node_runtime_perf_counter_cb) (vm));
    return 0ULL;
  }
  
  always_inline void
  vlib_process_update_stats (vlib_main_t * vm,
  			   vlib_process_t * p,
  			   uword n_calls, uword n_vectors, uword n_clocks,
  			   uword n_ticks)
  {
    vlib_node_runtime_update_stats (vm, &p->node_runtime,
  				  n_calls, n_vectors, n_clocks, n_ticks);
  }
  
  static clib_error_t *
  vlib_cli_elog_clear (vlib_main_t * vm,
  		     unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    elog_reset_buffer (&vm->elog_main);
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_clear_cli, static) = {
    .path = "event-logger clear",
    .short_help = "Clear the event log",
    .function = vlib_cli_elog_clear,
  };
  /* *INDENT-ON* */
  
  #ifdef CLIB_UNIX
  static clib_error_t *
  elog_save_buffer (vlib_main_t * vm,
  		  unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    elog_main_t *em = &vm->elog_main;
    char *file, *chroot_file;
    clib_error_t *error = 0;
  
    if (!unformat (input, "%s", &file))
      {
        vlib_cli_output (vm, "expected file name, got `%U'",
  		       format_unformat_error, input);
        return 0;
      }
  
    /* It's fairly hard to get "../oopsie" through unformat; just in case */
    if (strstr (file, "..") || index (file, '/'))
      {
        vlib_cli_output (vm, "illegal characters in filename '%s'", file);
        return 0;
      }
  
    chroot_file = (char *) format (0, "/tmp/%s%c", file, 0);
  
    vec_free (file);
  
    vlib_cli_output (vm, "Saving %wd of %wd events to %s",
  		   elog_n_events_in_buffer (em),
  		   elog_buffer_capacity (em), chroot_file);
  
    vlib_worker_thread_barrier_sync (vm);
    error = elog_write_file (em, chroot_file, 1 /* flush ring */ );
    vlib_worker_thread_barrier_release (vm);
    vec_free (chroot_file);
    return error;
  }
  
  void
  elog_post_mortem_dump (void)
  {
    vlib_main_t *vm = &vlib_global_main;
    elog_main_t *em = &vm->elog_main;
    u8 *filename;
    clib_error_t *error;
  
    if (!vm->elog_post_mortem_dump)
      return;
  
    filename = format (0, "/tmp/elog_post_mortem.%d%c", getpid (), 0);
    error = elog_write_file (em, (char *) filename, 1 /* flush ring */ );
    if (error)
      clib_error_report (error);
    vec_free (filename);
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_save_cli, static) = {
    .path = "event-logger save",
    .short_help = "event-logger save <filename> (saves log in /tmp/<filename>)",
    .function = elog_save_buffer,
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  elog_stop (vlib_main_t * vm,
  	   unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    elog_main_t *em = &vm->elog_main;
  
    em->n_total_events_disable_limit = em->n_total_events;
  
    vlib_cli_output (vm, "Stopped the event logger...");
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_stop_cli, static) = {
    .path = "event-logger stop",
    .short_help = "Stop the event-logger",
    .function = elog_stop,
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  elog_restart (vlib_main_t * vm,
  	      unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    elog_main_t *em = &vm->elog_main;
  
    em->n_total_events_disable_limit = ~0;
  
    vlib_cli_output (vm, "Restarted the event logger...");
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_restart_cli, static) = {
    .path = "event-logger restart",
    .short_help = "Restart the event-logger",
    .function = elog_restart,
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  elog_resize (vlib_main_t * vm,
  	     unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    elog_main_t *em = &vm->elog_main;
    u32 tmp;
  
    /* Stop the parade */
    elog_reset_buffer (&vm->elog_main);
  
    if (unformat (input, "%d", &tmp))
      {
        elog_alloc (em, tmp);
        em->n_total_events_disable_limit = ~0;
      }
    else
      return clib_error_return (0, "Must specify how many events in the ring");
  
    vlib_cli_output (vm, "Resized ring and restarted the event logger...");
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_resize_cli, static) = {
    .path = "event-logger resize",
    .short_help = "event-logger resize <nnn>",
    .function = elog_resize,
  };
  /* *INDENT-ON* */
  
  #endif /* CLIB_UNIX */
  
  static void
  elog_show_buffer_internal (vlib_main_t * vm, u32 n_events_to_show)
  {
    elog_main_t *em = &vm->elog_main;
    elog_event_t *e, *es;
    f64 dt;
  
    /* Show events in VLIB time since log clock starts after VLIB clock. */
    dt = (em->init_time.cpu - vm->clib_time.init_cpu_time)
      * vm->clib_time.seconds_per_clock;
  
    es = elog_peek_events (em);
    vlib_cli_output (vm, "%d of %d events in buffer, logger %s", vec_len (es),
  		   em->event_ring_size,
  		   em->n_total_events < em->n_total_events_disable_limit ?
  		   "running" : "stopped");
    vec_foreach (e, es)
    {
      vlib_cli_output (vm, "%18.9f: %U",
  		     e->time + dt, format_elog_event, em, e);
      n_events_to_show--;
      if (n_events_to_show == 0)
        break;
    }
    vec_free (es);
  
  }
  
  static clib_error_t *
  elog_show_buffer (vlib_main_t * vm,
  		  unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    u32 n_events_to_show;
    clib_error_t *error = 0;
  
    n_events_to_show = 250;
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (input, "%d", &n_events_to_show))
  	;
        else if (unformat (input, "all"))
  	n_events_to_show = ~0;
        else
  	return unformat_parse_error (input);
      }
    elog_show_buffer_internal (vm, n_events_to_show);
    return error;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (elog_show_cli, static) = {
    .path = "show event-logger",
    .short_help = "Show event logger info",
    .function = elog_show_buffer,
  };
  /* *INDENT-ON* */
  
  void
  vlib_gdb_show_event_log (void)
  {
    elog_show_buffer_internal (vlib_get_main (), (u32) ~ 0);
  }
  
  static inline void
  vlib_elog_main_loop_event (vlib_main_t * vm,
  			   u32 node_index,
  			   u64 time, u32 n_vectors, u32 is_return)
  {
    vlib_main_t *evm = &vlib_global_main;
    elog_main_t *em = &evm->elog_main;
  
    if (VLIB_ELOG_MAIN_LOOP && n_vectors)
      elog_track (em,
  		/* event type */
  		vec_elt_at_index (is_return
  				  ? evm->node_return_elog_event_types
  				  : evm->node_call_elog_event_types,
  				  node_index),
  		/* track */
  		(vm->thread_index ? &vlib_worker_threads[vm->thread_index].
  		 elog_track : &em->default_track),
  		/* data to log */ n_vectors);
  }
  
  #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
  void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 node_index);
  void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
  
  void
  vlib_buffer_trace_trajectory_init (vlib_buffer_t * b)
  {
    if (PREDICT_TRUE (vlib_buffer_trace_trajectory_init_cb != 0))
      {
        (*vlib_buffer_trace_trajectory_init_cb) (b);
      }
  }
  
  #endif
  
  static inline void
  add_trajectory_trace (vlib_buffer_t * b, u32 node_index)
  {
  #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
    if (PREDICT_TRUE (vlib_buffer_trace_trajectory_cb != 0))
      {
        (*vlib_buffer_trace_trajectory_cb) (b, node_index);
      }
  #endif
  }
  
  static void
  dispatch_pcap_trace (vlib_main_t * vm,
  		     vlib_node_runtime_t * node, vlib_frame_t * frame)
  {
    int i;
    vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **bufp, *b;
    u8 name_tlv[64];
    pcap_main_t *pm = &vm->dispatch_pcap_main;
    vlib_trace_main_t *tm = &vm->trace_main;
    u32 capture_size;
    vlib_node_t *n;
    u8 *packet_trace = 0;
    i32 n_left;
    f64 time_now = vlib_time_now (vm);
    u32 *from;
    u32 name_length;
    u16 trace_length;
    u8 version[2];
    u8 *d;
  
    /* Input nodes don't have frames yet */
    if (frame == 0 || frame->n_vectors == 0)
      return;
  
    from = vlib_frame_vector_args (frame);
    vlib_get_buffers (vm, from, bufs, frame->n_vectors);
    bufp = bufs;
  
    /* Create a node name TLV, since WS can't possibly guess */
    n = vlib_get_node (vm, node->node_index);
    name_length = vec_len (n->name);
    name_length = name_length < ARRAY_LEN (name_tlv) - 2 ?
      name_length : ARRAY_LEN (name_tlv) - 2;
  
    name_tlv[0] = (u8) name_length;
    clib_memcpy_fast (name_tlv + 1, n->name, name_length);
    name_tlv[name_length + 1] = 0;
  
    for (i = 0; i < frame->n_vectors; i++)
      {
        if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
  	{
  	  b = bufp[i];
  
  	  version[0] = VLIB_PCAP_MAJOR_VERSION;
  	  version[1] = VLIB_PCAP_MINOR_VERSION;
  
  	  vec_reset_length (packet_trace);
  
  	  /* Is this packet traced? */
  	  if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
  	    {
  	      vlib_trace_header_t **h
  		= pool_elt_at_index (tm->trace_buffer_pool, b->trace_index);
  
  	      packet_trace = format (packet_trace, "%U%c",
  				     format_vlib_trace, vm, h[0], 0);
  	    }
  
  	  /* Figure out how many bytes we're capturing */
            /* *INDENT-OFF* */
  	  capture_size = (sizeof (vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
              + sizeof (version)
              + vlib_buffer_length_in_chain (vm, b)
              + sizeof (u32) + (name_length + 2)	/* +2: count plus NULL byte */
  	    + (vec_len (packet_trace) + 2);	/* +2: trace count */
            /* *INDENT-ON* */
  
  	  clib_spinlock_lock_if_init (&pm->lock);
  	  n_left = clib_min (capture_size, 16384);
  	  d = pcap_add_packet (pm, time_now, n_left, capture_size);
  
  	  /* Copy the (major, minor) version numbers */
  	  clib_memcpy_fast (d, version, sizeof (version));
  	  d += sizeof (version);
  
  	  /* Copy the buffer index */
  	  clib_memcpy_fast (d, &from[i], sizeof (u32));
  	  d += 4;
  
  	  /* Copy the name TLV */
  	  clib_memcpy_fast (d, name_tlv, name_length + 2);
  	  d += name_length + 2;
  
  	  /* Copy the buffer metadata, but not the rewrite space */
  	  clib_memcpy_fast (d, b, sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE);
  	  d += sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE;
  
  	  trace_length = vec_len (packet_trace);
  	  /* Copy the trace data length (may be zero) */
  	  clib_memcpy_fast (d, &trace_length, sizeof (trace_length));
  	  d += 2;
  
  	  /* Copy packet trace data (if any) */
  	  if (vec_len (packet_trace))
  	    clib_memcpy_fast (d, packet_trace, vec_len (packet_trace));
  
  	  d += vec_len (packet_trace);
  
  	  n_left = clib_min
  	    (vlib_buffer_length_in_chain (vm, b),
  	     16384 -
  	     ((sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE) +
  	      (trace_length + 2)));
  	  /* Copy the packet data */
  	  while (1)
  	    {
  	      u32 copy_length = clib_min ((u32) n_left, b->current_length);
  	      clib_memcpy_fast (d, b->data + b->current_data, copy_length);
  	      n_left -= b->current_length;
  	      if (n_left <= 0)
  		break;
  	      d += b->current_length;
  	      ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
  	      b = vlib_get_buffer (vm, b->next_buffer);
  	    }
  	  clib_spinlock_unlock_if_init (&pm->lock);
  	}
      }
    vec_free (packet_trace);
  }
  
  static_always_inline u64
  dispatch_node (vlib_main_t * vm,
  	       vlib_node_runtime_t * node,
  	       vlib_node_type_t type,
  	       vlib_node_state_t dispatch_state,
  	       vlib_frame_t * frame, u64 last_time_stamp)
  {
    uword n, v;
    u64 t;
    vlib_node_main_t *nm = &vm->node_main;
    vlib_next_frame_t *nf;
  
    if (CLIB_DEBUG > 0)
      {
        vlib_node_t *n = vlib_get_node (vm, node->node_index);
        ASSERT (n->type == type);
      }
  
    /* Only non-internal nodes may be disabled. */
    if (type != VLIB_NODE_TYPE_INTERNAL && node->state != dispatch_state)
      {
        ASSERT (type != VLIB_NODE_TYPE_INTERNAL);
        return last_time_stamp;
      }
  
    if ((type == VLIB_NODE_TYPE_PRE_INPUT || type == VLIB_NODE_TYPE_INPUT)
        && dispatch_state != VLIB_NODE_STATE_INTERRUPT)
      {
        u32 c = node->input_main_loops_per_call;
        /* Only call node when count reaches zero. */
        if (c)
  	{
  	  node->input_main_loops_per_call = c - 1;
  	  return last_time_stamp;
  	}
      }
  
    /* Speculatively prefetch next frames. */
    if (node->n_next_nodes > 0)
      {
        nf = vec_elt_at_index (nm->next_frames, node->next_frame_index);
        CLIB_PREFETCH (nf, 4 * sizeof (nf[0]), WRITE);
      }
  
    vm->cpu_time_last_node_dispatch = last_time_stamp;
  
    if (1 /* || vm->thread_index == node->thread_index */ )
      {
        u64 pmc_before, pmc_delta;
  
        vlib_elog_main_loop_event (vm, node->node_index,
  				 last_time_stamp,
  				 frame ? frame->n_vectors : 0,
  				 /* is_after */ 0);
  
        /*
         * To validate accounting: pmc_before = last_time_stamp
         * perf ticks should equal clocks/pkt...
         */
        pmc_before = vlib_node_runtime_perf_counter (vm);
  
        /*
         * Turn this on if you run into
         * "bad monkey" contexts, and you want to know exactly
         * which nodes they've visited... See ixge.c...
         */
        if (VLIB_BUFFER_TRACE_TRAJECTORY && frame)
  	{
  	  int i;
  	  u32 *from;
  	  from = vlib_frame_vector_args (frame);
  	  for (i = 0; i < frame->n_vectors; i++)
  	    {
  	      vlib_buffer_t *b = vlib_get_buffer (vm, from[i]);
  	      add_trajectory_trace (b, node->node_index);
  	    }
  	  if (PREDICT_FALSE (vm->dispatch_pcap_enable))
  	    dispatch_pcap_trace (vm, node, frame);
  	  n = node->function (vm, node, frame);
  	}
        else
  	{
  	  if (PREDICT_FALSE (vm->dispatch_pcap_enable))
  	    dispatch_pcap_trace (vm, node, frame);
  	  n = node->function (vm, node, frame);
  	}
  
        t = clib_cpu_time_now ();
  
        /*
         * To validate accounting: pmc_delta = t - pmc_before;
         * perf ticks should equal clocks/pkt...
         */
        pmc_delta = vlib_node_runtime_perf_counter (vm) - pmc_before;
  
        vlib_elog_main_loop_event (vm, node->node_index, t, n,	/* is_after */
  				 1);
  
        vm->main_loop_vectors_processed += n;
        vm->main_loop_nodes_processed += n > 0;
  
        v = vlib_node_runtime_update_stats (vm, node,
  					  /* n_calls */ 1,
  					  /* n_vectors */ n,
  					  /* n_clocks */ t - last_time_stamp,
  					  pmc_delta /* PMC ticks */ );
  
        /* When in interrupt mode and vector rate crosses threshold switch to
           polling mode. */
        if ((dispatch_state == VLIB_NODE_STATE_INTERRUPT)
  	  || (dispatch_state == VLIB_NODE_STATE_POLLING
  	      && (node->flags
  		  & VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE)))
  	{
  #ifdef DISPATCH_NODE_ELOG_REQUIRED
  	  ELOG_TYPE_DECLARE (e) =
  	  {
  	    .function = (char *) __FUNCTION__,.format =
  	      "%s vector length %d, switching to %s",.format_args =
  	      "T4i4t4",.n_enum_strings = 2,.enum_strings =
  	    {
  	  "interrupt", "polling",},};
  	  struct
  	  {
  	    u32 node_name, vector_length, is_polling;
  	  } *ed;
  	  vlib_worker_thread_t *w = vlib_worker_threads + vm->thread_index;
  #endif
  
  	  if ((dispatch_state == VLIB_NODE_STATE_INTERRUPT
  	       && v >= nm->polling_threshold_vector_length) &&
  	      !(node->flags &
  		VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE))
  	    {
  	      vlib_node_t *n = vlib_get_node (vm, node->node_index);
  	      n->state = VLIB_NODE_STATE_POLLING;
  	      node->state = VLIB_NODE_STATE_POLLING;
  	      node->flags &=
  		~VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE;
  	      node->flags |=
  		VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE;
  	      nm->input_node_counts_by_state[VLIB_NODE_STATE_INTERRUPT] -= 1;
  	      nm->input_node_counts_by_state[VLIB_NODE_STATE_POLLING] += 1;
  
  #ifdef DISPATCH_NODE_ELOG_REQUIRED
  	      ed = ELOG_TRACK_DATA (&vlib_global_main.elog_main, e,
  				    w->elog_track);
  	      ed->node_name = n->name_elog_string;
  	      ed->vector_length = v;
  	      ed->is_polling = 1;
  #endif
  	    }
  	  else if (dispatch_state == VLIB_NODE_STATE_POLLING
  		   && v <= nm->interrupt_threshold_vector_length)
  	    {
  	      vlib_node_t *n = vlib_get_node (vm, node->node_index);
  	      if (node->flags &
  		  VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE)
  		{
  		  /* Switch to interrupt mode after dispatch in polling one more time.
  		     This allows driver to re-enable interrupts. */
  		  n->state = VLIB_NODE_STATE_INTERRUPT;
  		  node->state = VLIB_NODE_STATE_INTERRUPT;
  		  node->flags &=
  		    ~VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE;
  		  nm->input_node_counts_by_state[VLIB_NODE_STATE_POLLING] -=
  		    1;
  		  nm->input_node_counts_by_state[VLIB_NODE_STATE_INTERRUPT] +=
  		    1;
  
  		}
  	      else
  		{
  		  node->flags |=
  		    VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE;
  #ifdef DISPATCH_NODE_ELOG_REQUIRED
  		  ed = ELOG_TRACK_DATA (&vlib_global_main.elog_main, e,
  					w->elog_track);
  		  ed->node_name = n->name_elog_string;
  		  ed->vector_length = v;
  		  ed->is_polling = 0;
  #endif
  		}
  	    }
  	}
      }
  
    return t;
  }
  
  static u64
  dispatch_pending_node (vlib_main_t * vm, uword pending_frame_index,
  		       u64 last_time_stamp)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_frame_t *f;
    vlib_next_frame_t *nf, nf_dummy;
    vlib_node_runtime_t *n;
    u32 restore_frame_index;
    vlib_pending_frame_t *p;
  
    /* See comment below about dangling references to nm->pending_frames */
    p = nm->pending_frames + pending_frame_index;
  
    n = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INTERNAL],
  			p->node_runtime_index);
  
    f = vlib_get_frame (vm, p->frame_index);
    if (p->next_frame_index == VLIB_PENDING_FRAME_NO_NEXT_FRAME)
      {
        /* No next frame: so use dummy on stack. */
        nf = &nf_dummy;
        nf->flags = f->frame_flags & VLIB_NODE_FLAG_TRACE;
        nf->frame_index = ~p->frame_index;
      }
    else
      nf = vec_elt_at_index (nm->next_frames, p->next_frame_index);
  
    ASSERT (f->frame_flags & VLIB_FRAME_IS_ALLOCATED);
  
    /* Force allocation of new frame while current frame is being
       dispatched. */
    restore_frame_index = ~0;
    if (nf->frame_index == p->frame_index)
      {
        nf->frame_index = ~0;
        nf->flags &= ~VLIB_FRAME_IS_ALLOCATED;
        if (!(n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH))
  	restore_frame_index = p->frame_index;
      }
  
    /* Frame must be pending. */
    ASSERT (f->frame_flags & VLIB_FRAME_PENDING);
    ASSERT (f->n_vectors > 0);
  
    /* Copy trace flag from next frame to node.
       Trace flag indicates that at least one vector in the dispatched
       frame is traced. */
    n->flags &= ~VLIB_NODE_FLAG_TRACE;
    n->flags |= (nf->flags & VLIB_FRAME_TRACE) ? VLIB_NODE_FLAG_TRACE : 0;
    nf->flags &= ~VLIB_FRAME_TRACE;
  
    last_time_stamp = dispatch_node (vm, n,
  				   VLIB_NODE_TYPE_INTERNAL,
  				   VLIB_NODE_STATE_POLLING,
  				   f, last_time_stamp);
  
    f->frame_flags &= ~VLIB_FRAME_PENDING;
  
    /* Frame is ready to be used again, so restore it. */
    if (restore_frame_index != ~0)
      {
        /*
         * We musn't restore a frame that is flagged to be freed. This
         * shouldn't happen since frames to be freed post dispatch are
         * those used when the to-node frame becomes full i.e. they form a
         * sort of queue of frames to a single node. If we get here then
         * the to-node frame and the pending frame *were* the same, and so
         * we removed the to-node frame.  Therefore this frame is no
         * longer part of the queue for that node and hence it cannot be
         * it's overspill.
         */
        ASSERT (!(f->frame_flags & VLIB_FRAME_FREE_AFTER_DISPATCH));
  
        /*
         * NB: dispatching node n can result in the creation and scheduling
         * of new frames, and hence in the reallocation of nm->pending_frames.
         * Recompute p, or no supper. This was broken for more than 10 years.
         */
        p = nm->pending_frames + pending_frame_index;
  
        /*
         * p->next_frame_index can change during node dispatch if node
         * function decides to change graph hook up.
         */
        nf = vec_elt_at_index (nm->next_frames, p->next_frame_index);
        nf->flags |= VLIB_FRAME_IS_ALLOCATED;
  
        if (~0 == nf->frame_index)
  	{
  	  /* no new frame has been assigned to this node, use the saved one */
  	  nf->frame_index = restore_frame_index;
  	  f->n_vectors = 0;
  	}
        else
  	{
  	  /* The node has gained a frame, implying packets from the current frame
  	     were re-queued to this same node. we don't need the saved one
  	     anymore */
  	  vlib_frame_free (vm, n, f);
  	}
      }
    else
      {
        if (f->frame_flags & VLIB_FRAME_FREE_AFTER_DISPATCH)
  	{
  	  ASSERT (!(n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH));
  	  vlib_frame_free (vm, n, f);
  	}
      }
  
    return last_time_stamp;
  }
  
  always_inline uword
  vlib_process_stack_is_valid (vlib_process_t * p)
  {
    return p->stack[0] == VLIB_PROCESS_STACK_MAGIC;
  }
  
  typedef struct
  {
    vlib_main_t *vm;
    vlib_process_t *process;
    vlib_frame_t *frame;
  } vlib_process_bootstrap_args_t;
  
  /* Called in process stack. */
  static uword
  vlib_process_bootstrap (uword _a)
  {
    vlib_process_bootstrap_args_t *a;
    vlib_main_t *vm;
    vlib_node_runtime_t *node;
    vlib_frame_t *f;
    vlib_process_t *p;
    uword n;
  
    a = uword_to_pointer (_a, vlib_process_bootstrap_args_t *);
  
    vm = a->vm;
    p = a->process;
    f = a->frame;
    node = &p->node_runtime;
  
    n = node->function (vm, node, f);
  
    ASSERT (vlib_process_stack_is_valid (p));
  
    clib_longjmp (&p->return_longjmp, n);
  
    return n;
  }
  
  /* Called in main stack. */
  static_always_inline uword
  vlib_process_startup (vlib_main_t * vm, vlib_process_t * p, vlib_frame_t * f)
  {
    vlib_process_bootstrap_args_t a;
    uword r;
  
    a.vm = vm;
    a.process = p;
    a.frame = f;
  
    r = clib_setjmp (&p->return_longjmp, VLIB_PROCESS_RETURN_LONGJMP_RETURN);
    if (r == VLIB_PROCESS_RETURN_LONGJMP_RETURN)
      r = clib_calljmp (vlib_process_bootstrap, pointer_to_uword (&a),
  		      (void *) p->stack + (1 << p->log2_n_stack_bytes));
  
    return r;
  }
  
  static_always_inline uword
  vlib_process_resume (vlib_process_t * p)
  {
    uword r;
    p->flags &= ~(VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
  		| VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT
  		| VLIB_PROCESS_RESUME_PENDING);
    r = clib_setjmp (&p->return_longjmp, VLIB_PROCESS_RETURN_LONGJMP_RETURN);
    if (r == VLIB_PROCESS_RETURN_LONGJMP_RETURN)
      clib_longjmp (&p->resume_longjmp, VLIB_PROCESS_RESUME_LONGJMP_RESUME);
    return r;
  }
  
  static u64
  dispatch_process (vlib_main_t * vm,
  		  vlib_process_t * p, vlib_frame_t * f, u64 last_time_stamp)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_node_runtime_t *node_runtime = &p->node_runtime;
    vlib_node_t *node = vlib_get_node (vm, node_runtime->node_index);
    u32 old_process_index;
    u64 t;
    uword n_vectors, is_suspend;
  
    if (node->state != VLIB_NODE_STATE_POLLING
        || (p->flags & (VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
  		      | VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT)))
      return last_time_stamp;
  
    p->flags |= VLIB_PROCESS_IS_RUNNING;
  
    t = last_time_stamp;
    vlib_elog_main_loop_event (vm, node_runtime->node_index, t,
  			     f ? f->n_vectors : 0, /* is_after */ 0);
  
    /* Save away current process for suspend. */
    old_process_index = nm->current_process_index;
    nm->current_process_index = node->runtime_index;
  
    n_vectors = vlib_process_startup (vm, p, f);
  
    nm->current_process_index = old_process_index;
  
    ASSERT (n_vectors != VLIB_PROCESS_RETURN_LONGJMP_RETURN);
    is_suspend = n_vectors == VLIB_PROCESS_RETURN_LONGJMP_SUSPEND;
    if (is_suspend)
      {
        vlib_pending_frame_t *pf;
  
        n_vectors = 0;
        pool_get (nm->suspended_process_frames, pf);
        pf->node_runtime_index = node->runtime_index;
        pf->frame_index = f ? vlib_frame_index (vm, f) : ~0;
        pf->next_frame_index = ~0;
  
        p->n_suspends += 1;
        p->suspended_process_frame_index = pf - nm->suspended_process_frames;
  
        if (p->flags & VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK)
  	{
  	  TWT (tw_timer_wheel) * tw =
  	    (TWT (tw_timer_wheel) *) nm->timing_wheel;
  	  p->stop_timer_handle =
  	    TW (tw_timer_start) (tw,
  				 vlib_timing_wheel_data_set_suspended_process
  				 (node->runtime_index) /* [sic] pool idex */ ,
  				 0 /* timer_id */ ,
  				 p->resume_clock_interval);
  	}
      }
    else
      p->flags &= ~VLIB_PROCESS_IS_RUNNING;
  
    t = clib_cpu_time_now ();
  
    vlib_elog_main_loop_event (vm, node_runtime->node_index, t, is_suspend,
  			     /* is_after */ 1);
  
    vlib_process_update_stats (vm, p,
  			     /* n_calls */ !is_suspend,
  			     /* n_vectors */ n_vectors,
  			     /* n_clocks */ t - last_time_stamp,
  			     /* pmc_ticks */ 0ULL);
  
    return t;
  }
  
  void
  vlib_start_process (vlib_main_t * vm, uword process_index)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_process_t *p = vec_elt (nm->processes, process_index);
    dispatch_process (vm, p, /* frame */ 0, /* cpu_time_now */ 0);
  }
  
  static u64
  dispatch_suspended_process (vlib_main_t * vm,
  			    uword process_index, u64 last_time_stamp)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_node_runtime_t *node_runtime;
    vlib_node_t *node;
    vlib_frame_t *f;
    vlib_process_t *p;
    vlib_pending_frame_t *pf;
    u64 t, n_vectors, is_suspend;
  
    t = last_time_stamp;
  
    p = vec_elt (nm->processes, process_index);
    if (PREDICT_FALSE (!(p->flags & VLIB_PROCESS_IS_RUNNING)))
      return last_time_stamp;
  
    ASSERT (p->flags & (VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
  		      | VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT));
  
    pf = pool_elt_at_index (nm->suspended_process_frames,
  			  p->suspended_process_frame_index);
  
    node_runtime = &p->node_runtime;
    node = vlib_get_node (vm, node_runtime->node_index);
    f = pf->frame_index != ~0 ? vlib_get_frame (vm, pf->frame_index) : 0;
  
    vlib_elog_main_loop_event (vm, node_runtime->node_index, t,
  			     f ? f->n_vectors : 0, /* is_after */ 0);
  
    /* Save away current process for suspend. */
    nm->current_process_index = node->runtime_index;
  
    n_vectors = vlib_process_resume (p);
    t = clib_cpu_time_now ();
  
    nm->current_process_index = ~0;
  
    is_suspend = n_vectors == VLIB_PROCESS_RETURN_LONGJMP_SUSPEND;
    if (is_suspend)
      {
        /* Suspend it again. */
        n_vectors = 0;
        p->n_suspends += 1;
        if (p->flags & VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK)
  	{
  	  p->stop_timer_handle =
  	    TW (tw_timer_start) ((TWT (tw_timer_wheel) *) nm->timing_wheel,
  				 vlib_timing_wheel_data_set_suspended_process
  				 (node->runtime_index) /* [sic] pool idex */ ,
  				 0 /* timer_id */ ,
  				 p->resume_clock_interval);
  	}
      }
    else
      {
        p->flags &= ~VLIB_PROCESS_IS_RUNNING;
        pool_put_index (nm->suspended_process_frames,
  		      p->suspended_process_frame_index);
        p->suspended_process_frame_index = ~0;
      }
  
    t = clib_cpu_time_now ();
    vlib_elog_main_loop_event (vm, node_runtime->node_index, t, !is_suspend,
  			     /* is_after */ 1);
  
    vlib_process_update_stats (vm, p,
  			     /* n_calls */ !is_suspend,
  			     /* n_vectors */ n_vectors,
  			     /* n_clocks */ t - last_time_stamp,
  			     /* pmc_ticks */ 0ULL);
  
    return t;
  }
  
  void vl_api_send_pending_rpc_requests (vlib_main_t *) __attribute__ ((weak));
  void
  vl_api_send_pending_rpc_requests (vlib_main_t * vm)
  {
  }
  
  
  static_always_inline void
  vlib_main_or_worker_loop (vlib_main_t * vm, int is_main)
  {
    vlib_node_main_t *nm = &vm->node_main;
    vlib_thread_main_t *tm = vlib_get_thread_main ();
    uword i;
    u64 cpu_time_now;
    vlib_frame_queue_main_t *fqm;
    u32 *last_node_runtime_indices = 0;
  
    /* Initialize pending node vector. */
    if (is_main)
      {
        vec_resize (nm->pending_frames, 32);
        _vec_len (nm->pending_frames) = 0;
      }
  
    /* Mark time of main loop start. */
    if (is_main)
      {
        cpu_time_now = vm->clib_time.last_cpu_time;
        vm->cpu_time_main_loop_start = cpu_time_now;
      }
    else
      cpu_time_now = clib_cpu_time_now ();
  
    /* Pre-allocate interupt runtime indices and lock. */
    vec_alloc (nm->pending_interrupt_node_runtime_indices, 32);
    vec_alloc (last_node_runtime_indices, 32);
    if (!is_main)
      clib_spinlock_init (&nm->pending_interrupt_lock);
  
    /* Pre-allocate expired nodes. */
    if (!nm->polling_threshold_vector_length)
      nm->polling_threshold_vector_length = 10;
    if (!nm->interrupt_threshold_vector_length)
      nm->interrupt_threshold_vector_length = 5;
  
    /* Make sure the performance monitor counter is disabled */
    vm->perf_counter_id = ~0;
  
    /* Start all processes. */
    if (is_main)
      {
        uword i;
        nm->current_process_index = ~0;
        for (i = 0; i < vec_len (nm->processes); i++)
  	cpu_time_now = dispatch_process (vm, nm->processes[i], /* frame */ 0,
  					 cpu_time_now);
      }
  
    while (1)
      {
        vlib_node_runtime_t *n;
  
        if (PREDICT_FALSE (_vec_len (vm->pending_rpc_requests) > 0))
  	{
  	  if (!is_main)
  	    vl_api_send_pending_rpc_requests (vm);
  	}
  
        if (!is_main)
  	{
  	  vlib_worker_thread_barrier_check ();
  	  vec_foreach (fqm, tm->frame_queue_mains)
  	    vlib_frame_queue_dequeue (vm, fqm);
  	  if (PREDICT_FALSE (vm->worker_thread_main_loop_callback != 0))
  	    ((void (*)(vlib_main_t *)) vm->worker_thread_main_loop_callback)
  	      (vm);
  	}
  
        /* Process pre-input nodes. */
        vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_PRE_INPUT])
  	cpu_time_now = dispatch_node (vm, n,
  				      VLIB_NODE_TYPE_PRE_INPUT,
  				      VLIB_NODE_STATE_POLLING,
  				      /* frame */ 0,
  				      cpu_time_now);
  
        /* Next process input nodes. */
        vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_INPUT])
  	cpu_time_now = dispatch_node (vm, n,
  				      VLIB_NODE_TYPE_INPUT,
  				      VLIB_NODE_STATE_POLLING,
  				      /* frame */ 0,
  				      cpu_time_now);
  
        if (PREDICT_TRUE (is_main && vm->queue_signal_pending == 0))
  	vm->queue_signal_callback (vm);
  
        /* Next handle interrupts. */
        {
  	/* unlocked read, for performance */
  	uword l = _vec_len (nm->pending_interrupt_node_runtime_indices);
  	uword i;
  	if (PREDICT_FALSE (l > 0))
  	  {
  	    u32 *tmp;
  	    if (!is_main)
  	      {
  		clib_spinlock_lock (&nm->pending_interrupt_lock);
  		/* Re-read w/ lock held, in case another thread added an item */
  		l = _vec_len (nm->pending_interrupt_node_runtime_indices);
  	      }
  
  	    tmp = nm->pending_interrupt_node_runtime_indices;
  	    nm->pending_interrupt_node_runtime_indices =
  	      last_node_runtime_indices;
  	    last_node_runtime_indices = tmp;
  	    _vec_len (last_node_runtime_indices) = 0;
  	    if (!is_main)
  	      clib_spinlock_unlock (&nm->pending_interrupt_lock);
  	    for (i = 0; i < l; i++)
  	      {
  		n = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INPUT],
  				      last_node_runtime_indices[i]);
  		cpu_time_now =
  		  dispatch_node (vm, n, VLIB_NODE_TYPE_INPUT,
  				 VLIB_NODE_STATE_INTERRUPT,
  				 /* frame */ 0,
  				 cpu_time_now);
  	      }
  	  }
        }
        /* Input nodes may have added work to the pending vector.
           Process pending vector until there is nothing left.
           All pending vectors will be processed from input -> output. */
        for (i = 0; i < _vec_len (nm->pending_frames); i++)
  	cpu_time_now = dispatch_pending_node (vm, i, cpu_time_now);
        /* Reset pending vector for next iteration. */
        _vec_len (nm->pending_frames) = 0;
  
        if (is_main)
  	{
  	  /* Check if process nodes have expired from timing wheel. */
  	  ASSERT (nm->data_from_advancing_timing_wheel != 0);
  
  	  nm->data_from_advancing_timing_wheel =
  	    TW (tw_timer_expire_timers_vec)
  	    ((TWT (tw_timer_wheel) *) nm->timing_wheel, vlib_time_now (vm),
  	     nm->data_from_advancing_timing_wheel);
  
  	  ASSERT (nm->data_from_advancing_timing_wheel != 0);
  
  	  if (PREDICT_FALSE
  	      (_vec_len (nm->data_from_advancing_timing_wheel) > 0))
  	    {
  	      uword i;
  
  	      for (i = 0; i < _vec_len (nm->data_from_advancing_timing_wheel);
  		   i++)
  		{
  		  u32 d = nm->data_from_advancing_timing_wheel[i];
  		  u32 di = vlib_timing_wheel_data_get_index (d);
  
  		  if (vlib_timing_wheel_data_is_timed_event (d))
  		    {
  		      vlib_signal_timed_event_data_t *te =
  			pool_elt_at_index (nm->signal_timed_event_data_pool,
  					   di);
  		      vlib_node_t *n =
  			vlib_get_node (vm, te->process_node_index);
  		      vlib_process_t *p =
  			vec_elt (nm->processes, n->runtime_index);
  		      void *data;
  		      data =
  			vlib_process_signal_event_helper (nm, n, p,
  							  te->event_type_index,
  							  te->n_data_elts,
  							  te->n_data_elt_bytes);
  		      if (te->n_data_bytes < sizeof (te->inline_event_data))
  			clib_memcpy_fast (data, te->inline_event_data,
  					  te->n_data_bytes);
  		      else
  			{
  			  clib_memcpy_fast (data, te->event_data_as_vector,
  					    te->n_data_bytes);
  			  vec_free (te->event_data_as_vector);
  			}
  		      pool_put (nm->signal_timed_event_data_pool, te);
  		    }
  		  else
  		    {
  		      cpu_time_now = clib_cpu_time_now ();
  		      cpu_time_now =
  			dispatch_suspended_process (vm, di, cpu_time_now);
  		    }
  		}
  	      _vec_len (nm->data_from_advancing_timing_wheel) = 0;
  	    }
  	}
        vlib_increment_main_loop_counter (vm);
  
        /* Record time stamp in case there are no enabled nodes and above
           calls do not update time stamp. */
        cpu_time_now = clib_cpu_time_now ();
      }
  }
  
  static void
  vlib_main_loop (vlib_main_t * vm)
  {
    vlib_main_or_worker_loop (vm, /* is_main */ 1);
  }
  
  void
  vlib_worker_loop (vlib_main_t * vm)
  {
    vlib_main_or_worker_loop (vm, /* is_main */ 0);
  }
  
  vlib_main_t vlib_global_main;
  
  static clib_error_t *
  vlib_main_configure (vlib_main_t * vm, unformat_input_t * input)
  {
    int turn_on_mem_trace = 0;
  
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (input, "memory-trace"))
  	turn_on_mem_trace = 1;
  
        else if (unformat (input, "elog-events %d",
  			 &vm->elog_main.event_ring_size))
  	;
        else if (unformat (input, "elog-post-mortem-dump"))
  	vm->elog_post_mortem_dump = 1;
        else
  	return unformat_parse_error (input);
      }
  
    unformat_free (input);
  
    /* Enable memory trace as early as possible. */
    if (turn_on_mem_trace)
      clib_mem_trace (1);
  
    return 0;
  }
  
  VLIB_EARLY_CONFIG_FUNCTION (vlib_main_configure, "vlib");
  
  static void
  dummy_queue_signal_callback (vlib_main_t * vm)
  {
  }
  
  #define foreach_weak_reference_stub             \
  _(vlib_map_stat_segment_init)                   \
  _(vpe_api_init)                                 \
  _(vlibmemory_init)                              \
  _(map_api_segment_init)
  
  #define _(name)                                                 \
  clib_error_t *name (vlib_main_t *vm) __attribute__((weak));     \
  clib_error_t *name (vlib_main_t *vm) { return 0; }
  foreach_weak_reference_stub;
  #undef _
  
  /* Main function. */
  int
  vlib_main (vlib_main_t * volatile vm, unformat_input_t * input)
  {
    clib_error_t *volatile error;
    vlib_node_main_t *nm = &vm->node_main;
  
    vm->queue_signal_callback = dummy_queue_signal_callback;
  
    clib_time_init (&vm->clib_time);
  
    /* Turn on event log. */
    if (!vm->elog_main.event_ring_size)
      vm->elog_main.event_ring_size = 128 << 10;
    elog_init (&vm->elog_main, vm->elog_main.event_ring_size);
    elog_enable_disable (&vm->elog_main, 1);
  
    /* Default name. */
    if (!vm->name)
      vm->name = "VLIB";
  
    if ((error = vlib_physmem_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    if ((error = vlib_buffer_main_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    if ((error = vlib_thread_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    if ((error = vlib_map_stat_segment_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    /* Register static nodes so that init functions may use them. */
    vlib_register_all_static_nodes (vm);
  
    /* Set seed for random number generator.
       Allow user to specify seed to make random sequence deterministic. */
    if (!unformat (input, "seed %wd", &vm->random_seed))
      vm->random_seed = clib_cpu_time_now ();
    clib_random_buffer_init (&vm->random_buffer, vm->random_seed);
  
    /* Initialize node graph. */
    if ((error = vlib_node_main_init (vm)))
      {
        /* Arrange for graph hook up error to not be fatal when debugging. */
        if (CLIB_DEBUG > 0)
  	clib_error_report (error);
        else
  	goto done;
      }
  
    /* Direct call / weak reference, for vlib standalone use-cases */
    if ((error = vpe_api_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    if ((error = vlibmemory_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    if ((error = map_api_segment_init (vm)))
      {
        clib_error_report (error);
        goto done;
      }
  
    /* See unix/main.c; most likely already set up */
    if (vm->init_functions_called == 0)
      vm->init_functions_called = hash_create (0, /* value bytes */ 0);
    if ((error = vlib_call_all_init_functions (vm)))
      goto done;
  
    /* Create default buffer free list. */
    vlib_buffer_create_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES,
  				"default");
  
    nm->timing_wheel = clib_mem_alloc_aligned (sizeof (TWT (tw_timer_wheel)),
  					     CLIB_CACHE_LINE_BYTES);
  
    vec_validate (nm->data_from_advancing_timing_wheel, 10);
    _vec_len (nm->data_from_advancing_timing_wheel) = 0;
  
    /* Create the process timing wheel */
    TW (tw_timer_wheel_init) ((TWT (tw_timer_wheel) *) nm->timing_wheel,
  			    0 /* no callback */ ,
  			    10e-6 /* timer period 10us */ ,
  			    ~0 /* max expirations per call */ );
  
    vec_validate (vm->pending_rpc_requests, 0);
    _vec_len (vm->pending_rpc_requests) = 0;
    vec_validate (vm->processing_rpc_requests, 0);
    _vec_len (vm->processing_rpc_requests) = 0;
  
    switch (clib_setjmp (&vm->main_loop_exit, VLIB_MAIN_LOOP_EXIT_NONE))
      {
      case VLIB_MAIN_LOOP_EXIT_NONE:
        vm->main_loop_exit_set = 1;
        break;
  
      case VLIB_MAIN_LOOP_EXIT_CLI:
        goto done;
  
      default:
        error = vm->main_loop_error;
        goto done;
      }
  
    if ((error = vlib_call_all_config_functions (vm, input, 0 /* is_early */ )))
      goto done;
  
    /* Call all main loop enter functions. */
    {
      clib_error_t *sub_error;
      sub_error = vlib_call_all_main_loop_enter_functions (vm);
      if (sub_error)
        clib_error_report (sub_error);
    }
  
    vlib_main_loop (vm);
  
  done:
    /* Call all exit functions. */
    {
      clib_error_t *sub_error;
      sub_error = vlib_call_all_main_loop_exit_functions (vm);
      if (sub_error)
        clib_error_report (sub_error);
    }
  
    if (error)
      clib_error_report (error);
  
    return 0;
  }
  
  static inline clib_error_t *
  pcap_dispatch_trace_command_internal (vlib_main_t * vm,
  				      unformat_input_t * input,
  				      vlib_cli_command_t * cmd, int rx_tx)
  {
  #define PCAP_DEF_PKT_TO_CAPTURE (100)
  
    unformat_input_t _line_input, *line_input = &_line_input;
    pcap_main_t *pm = &vm->dispatch_pcap_main;
    u8 *filename;
    u8 *chroot_filename = 0;
    u32 max = 0;
    int enabled = 0;
    int errorFlag = 0;
    clib_error_t *error = 0;
    u32 node_index, add;
    vlib_trace_main_t *tm;
    vlib_trace_node_t *tn;
  
    /* Get a line of input. */
    if (!unformat_user (input, unformat_line_input, line_input))
      return 0;
  
    while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (line_input, "on"))
  	{
  	  if (vm->dispatch_pcap_enable == 0)
  	    {
  	      enabled = 1;
  	    }
  	  else
  	    {
  	      vlib_cli_output (vm, "pcap dispatch capture already on...");
  	      errorFlag = 1;
  	      break;
  	    }
  	}
        else if (unformat (line_input, "off"))
  	{
  	  if (vm->dispatch_pcap_enable)
  	    {
  	      vlib_cli_output
  		(vm, "captured %d pkts...", pm->n_packets_captured);
  	      if (pm->n_packets_captured)
  		{
  		  pm->n_packets_to_capture = pm->n_packets_captured;
  		  error = pcap_write (pm);
  		  if (error)
  		    clib_error_report (error);
  		  else
  		    vlib_cli_output (vm, "saved to %s...", pm->file_name);
  		}
  	      vm->dispatch_pcap_enable = 0;
  	    }
  	  else
  	    {
  	      vlib_cli_output (vm, "pcap tx capture already off...");
  	      errorFlag = 1;
  	      break;
  	    }
  	}
        else if (unformat (line_input, "max %d", &max))
  	{
  	  if (vm->dispatch_pcap_enable)
  	    {
  	      vlib_cli_output
  		(vm,
  		 "can't change max value while pcap tx capture active...");
  	      errorFlag = 1;
  	      break;
  	    }
  	  pm->n_packets_to_capture = max;
  	}
        else if (unformat (line_input, "file %s", &filename))
  	{
  	  if (vm->dispatch_pcap_enable)
  	    {
  	      vlib_cli_output
  		(vm, "can't change file while pcap tx capture active...");
  	      errorFlag = 1;
  	      break;
  	    }
  
  	  /* Brain-police user path input */
  	  if (strstr ((char *) filename, "..")
  	      || index ((char *) filename, '/'))
  	    {
  	      vlib_cli_output (vm, "illegal characters in filename '%s'",
  			       filename);
  	      vlib_cli_output (vm, "Hint: .. and / are not allowed.");
  	      vec_free (filename);
  	      errorFlag = 1;
  	      break;
  	    }
  
  	  chroot_filename = format (0, "/tmp/%s%c", filename, 0);
  	  vec_free (filename);
  	}
        else if (unformat (line_input, "status"))
  	{
  	  if (vm->dispatch_pcap_enable)
  	    {
  	      vlib_cli_output
  		(vm, "pcap dispatch capture is on: %d of %d pkts...",
  		 pm->n_packets_captured, pm->n_packets_to_capture);
  	      vlib_cli_output (vm, "Capture to file %s", pm->file_name);
  	    }
  	  else
  	    {
  	      vlib_cli_output (vm, "pcap dispatch capture is off...");
  	    }
  	  break;
  	}
        else if (unformat (line_input, "buffer-trace %U %d",
  			 unformat_vlib_node, vm, &node_index, &add))
  	{
  	  if (vnet_trace_dummy == 0)
  	    vec_validate_aligned (vnet_trace_dummy, 2048,
  				  CLIB_CACHE_LINE_BYTES);
  	  vlib_cli_output (vm, "Buffer tracing of %d pkts from %U enabled...",
  			   add, format_vlib_node_name, vm, node_index);
  
            /* *INDENT-OFF* */
            foreach_vlib_main ((
              {
                tm = &this_vlib_main->trace_main;
                tm->verbose = 0;  /* not sure this ever did anything... */
                vec_validate (tm->nodes, node_index);
                tn = tm->nodes + node_index;
                tn->limit += add;
                tm->trace_enable = 1;
              }));
            /* *INDENT-ON* */
  	}
  
        else
  	{
  	  error = clib_error_return (0, "unknown input `%U'",
  				     format_unformat_error, line_input);
  	  errorFlag = 1;
  	  break;
  	}
      }
    unformat_free (line_input);
  
  
    if (errorFlag == 0)
      {
        /* Since no error, save configured values. */
        if (chroot_filename)
  	{
  	  if (pm->file_name)
  	    vec_free (pm->file_name);
  	  vec_add1 (chroot_filename, 0);
  	  pm->file_name = (char *) chroot_filename;
  	}
  
        if (max)
  	pm->n_packets_to_capture = max;
  
        if (enabled)
  	{
  	  if (pm->file_name == 0)
  	    pm->file_name = (char *) format (0, "/tmp/dispatch.pcap%c", 0);
  
  	  pm->n_packets_captured = 0;
  	  pm->packet_type = PCAP_PACKET_TYPE_user13;
  	  if (pm->lock == 0)
  	    clib_spinlock_init (&(pm->lock));
  	  vm->dispatch_pcap_enable = 1;
  	  vlib_cli_output (vm, "pcap dispatch capture on...");
  	}
      }
    else if (chroot_filename)
      vec_free (chroot_filename);
  
    return error;
  }
  
  static clib_error_t *
  pcap_dispatch_trace_command_fn (vlib_main_t * vm,
  				unformat_input_t * input,
  				vlib_cli_command_t * cmd)
  {
    return pcap_dispatch_trace_command_internal (vm, input, cmd, VLIB_RX);
  }
  
  /*?
   * This command is used to start or stop pcap dispatch trace capture, or show
   * the capture status.
   *
   * This command has the following optional parameters:
   *
   * - <b>on|off</b> - Used to start or stop capture.
   *
   * - <b>max <nn></b> - Depth of local buffer. Once '<em>nn</em>' number
   *   of packets have been received, buffer is flushed to file. Once another
   *   '<em>nn</em>' number of packets have been received, buffer is flushed
   *   to file, overwriting previous write. If not entered, value defaults
   *   to 100. Can only be updated if packet capture is off.
   *
   * - <b>file <name></b> - Used to specify the output filename. The file will
   *   be placed in the '<em>/tmp</em>' directory, so only the filename is
   *   supported. Directory should not be entered. If file already exists, file
   *   will be overwritten. If no filename is provided, '<em>/tmp/vpe.pcap</em>'
   *   will be used. Can only be updated if packet capture is off.
   *
   * - <b>status</b> - Displays the current status and configured attributes
   *   associated with a packet capture. If packet capture is in progress,
   *   '<em>status</em>' also will return the number of packets currently in
   *   the local buffer. All additional attributes entered on command line
   *   with '<em>status</em>' will be ignored and not applied.
   *
   * @cliexpar
   * Example of how to display the status of capture when off:
   * @cliexstart{pcap dispatch trace status}
   * max is 100, for any interface to file /tmp/vpe.pcap
   * pcap dispatch capture is off...
   * @cliexend
   * Example of how to start a dispatch trace capture:
   * @cliexstart{pcap dispatch trace on max 35 file dispatchTrace.pcap}
   * pcap dispatch capture on...
   * @cliexend
   * Example of how to start a dispatch trace capture with buffer tracing
   * @cliexstart{pcap dispatch trace on max 10000 file dispatchTrace.pcap buffer-trace dpdk-input 1000}
   * pcap dispatch capture on...
   * @cliexend
   * Example of how to display the status of a tx packet capture in progress:
   * @cliexstart{pcap tx trace status}
   * max is 35, dispatch trace to file /tmp/vppTest.pcap
   * pcap tx capture is on: 20 of 35 pkts...
   * @cliexend
   * Example of how to stop a tx packet capture:
   * @cliexstart{vppctl pcap dispatch trace off}
   * captured 21 pkts...
   * saved to /tmp/dispatchTrace.pcap...
   * @cliexend
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (pcap_dispatch_trace_command, static) = {
      .path = "pcap dispatch trace",
      .short_help =
      "pcap dispatch trace [on|off] [max <nn>] [file <name>] [status]\n"
      "              [buffer-trace <input-node-name> <nn>]",
      .function = pcap_dispatch_trace_command_fn,
  };
  /* *INDENT-ON* */
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  