l2_input_vtr.c

Go to the documentation of this file.

/*
 * l2_input_vtr.c : layer 2 input vlan tag rewrite processing
 *
 * Copyright (c) 2013 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ethernet/packet.h>
#include <vnet/l2/l2_input.h>
#include <vnet/l2/feat_bitmap.h>
#include <vnet/l2/l2_vtr.h>
#include <vnet/l2/l2_input_vtr.h>
#include <vnet/l2/l2_output.h>

#include <vppinfra/error.h>
#include <vppinfra/cache.h>


typedef struct
{
  /* per-pkt trace data */
  u8 src[6];
  u8 dst[6];
  u8 raw[12];                   /* raw data (vlans) */
  u32 sw_if_index;
} l2_invtr_trace_t;

/* packet trace format function */
static u8 *
format_l2_invtr_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 *);
  l2_invtr_trace_t *t = va_arg (*args, l2_invtr_trace_t *);

  s = format (s, "l2-input-vtr: sw_if_index %d dst %U src %U data "
              "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
              t->sw_if_index,
              format_ethernet_address, t->dst,
              format_ethernet_address, t->src,
              t->raw[0], t->raw[1], t->raw[2], t->raw[3], t->raw[4],
              t->raw[5], t->raw[6], t->raw[7], t->raw[8], t->raw[9],
              t->raw[10], t->raw[11]);
  return s;
}

l2_invtr_main_t l2_invtr_main;

static vlib_node_registration_t l2_invtr_node;

#define foreach_l2_invtr_error                  \
_(L2_INVTR,    "L2 inverter packets")           \
_(DROP,        "L2 input tag rewrite drops")

typedef enum
{
#define _(sym,str) L2_INVTR_ERROR_##sym,
  foreach_l2_invtr_error
#undef _
    L2_INVTR_N_ERROR,
} l2_invtr_error_t;

static char *l2_invtr_error_strings[] = {
#define _(sym,string) string,
  foreach_l2_invtr_error
#undef _
};

typedef enum
{
  L2_INVTR_NEXT_DROP,
  L2_INVTR_N_NEXT,
} l2_invtr_next_t;


static uword
l2_invtr_node_fn (vlib_main_t * vm,
                  vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, *to_next;
  l2_invtr_next_t next_index;
  l2_invtr_main_t *msm = &l2_invtr_main;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;       /* number of packets to process */
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      /* get space to enqueue frame to graph node "next_index" */
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 6 && n_left_to_next >= 2)
        {
          u32 bi0, bi1;
          vlib_buffer_t *b0, *b1;
          u32 next0, next1;
          u32 sw_if_index0, sw_if_index1;
          u32 feature_bitmap0, feature_bitmap1;

          /* Prefetch next iteration. */
          {
            vlib_buffer_t *p2, *p3, *p4, *p5;
            u32 sw_if_index2, sw_if_index3;

            p2 = vlib_get_buffer (vm, from[2]);
            p3 = vlib_get_buffer (vm, from[3]);
            p4 = vlib_get_buffer (vm, from[4]);
            p5 = vlib_get_buffer (vm, from[5]);

            /* Prefetch the buffer header and packet for the N+2 loop iteration */
            vlib_prefetch_buffer_header (p4, LOAD);
            vlib_prefetch_buffer_header (p5, LOAD);

            CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);

            /*
             * Prefetch the input config for the N+1 loop iteration
             * This depends on the buffer header above
             */
            sw_if_index2 = vnet_buffer (p2)->sw_if_index[VLIB_RX];
            sw_if_index3 = vnet_buffer (p3)->sw_if_index[VLIB_RX];
            CLIB_PREFETCH (vec_elt_at_index
                           (l2output_main.configs, sw_if_index2),
                           CLIB_CACHE_LINE_BYTES, LOAD);
            CLIB_PREFETCH (vec_elt_at_index
                           (l2output_main.configs, sw_if_index3),
                           CLIB_CACHE_LINE_BYTES, LOAD);
          }

          /* speculatively enqueue b0 and b1 to the current next frame */
          /* bi is "buffer index", b is pointer to the buffer */
          to_next[0] = bi0 = from[0];
          to_next[1] = bi1 = from[1];
          from += 2;
          to_next += 2;
          n_left_from -= 2;
          n_left_to_next -= 2;

          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);

          /* RX interface handles */
          sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
          sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];

          /* process 2 packets */

          /* Remove ourself from the feature bitmap */
          feature_bitmap0 =
            vnet_buffer (b0)->l2.feature_bitmap & ~L2INPUT_FEAT_VTR;
          feature_bitmap1 =
            vnet_buffer (b1)->l2.feature_bitmap & ~L2INPUT_FEAT_VTR;

          /* save for next feature graph nodes */
          vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap0;
          vnet_buffer (b1)->l2.feature_bitmap = feature_bitmap1;

          /* Determine the next node */
          next0 = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
                                                   feature_bitmap0);
          next1 = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
                                                   feature_bitmap1);

          l2_output_config_t *config0;
          l2_output_config_t *config1;
          config0 = vec_elt_at_index (l2output_main.configs, sw_if_index0);
          config1 = vec_elt_at_index (l2output_main.configs, sw_if_index1);

          if (PREDICT_FALSE (config0->out_vtr_flag))
            {
              if (config0->output_vtr.push_and_pop_bytes)
                {
                  /* perform the tag rewrite on two packets */
                  if (l2_vtr_process
                      (b0,
                       &(vec_elt_at_index
                         (l2output_main.configs, sw_if_index0)->input_vtr)))
                    {
                      /* Drop packet */
                      next0 = L2_INVTR_NEXT_DROP;
                      b0->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
              else if (config0->output_pbb_vtr.push_and_pop_bytes)
                {
                  if (l2_pbb_process (b0, &(config0->input_pbb_vtr)))
                    {
                      /* Drop packet */
                      next0 = L2_INVTR_NEXT_DROP;
                      b0->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
            }
          if (PREDICT_FALSE (config1->out_vtr_flag))
            {
              if (config1->output_vtr.push_and_pop_bytes)
                {
                  if (l2_vtr_process
                      (b1,
                       &(vec_elt_at_index
                         (l2output_main.configs, sw_if_index1)->input_vtr)))
                    {
                      /* Drop packet */
                      next1 = L2_INVTR_NEXT_DROP;
                      b1->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
              else if (config1->output_pbb_vtr.push_and_pop_bytes)
                {
                  if (l2_pbb_process (b1, &(config1->input_pbb_vtr)))
                    {
                      /* Drop packet */
                      next1 = L2_INVTR_NEXT_DROP;
                      b1->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
            }

          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
            {
              if (b0->flags & VLIB_BUFFER_IS_TRACED)
                {
                  l2_invtr_trace_t *t =
                    vlib_add_trace (vm, node, b0, sizeof (*t));
                  ethernet_header_t *h0 = vlib_buffer_get_current (b0);
                  t->sw_if_index = sw_if_index0;
                  clib_memcpy (t->src, h0->src_address, 6);
                  clib_memcpy (t->dst, h0->dst_address, 6);
                  clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
                }
              if (b1->flags & VLIB_BUFFER_IS_TRACED)
                {
                  l2_invtr_trace_t *t =
                    vlib_add_trace (vm, node, b1, sizeof (*t));
                  ethernet_header_t *h1 = vlib_buffer_get_current (b1);
                  t->sw_if_index = sw_if_index0;
                  clib_memcpy (t->src, h1->src_address, 6);
                  clib_memcpy (t->dst, h1->dst_address, 6);
                  clib_memcpy (t->raw, &h1->type, sizeof (t->raw));
                }
            }

          /* verify speculative enqueues, maybe switch current next frame */
          /* if next0==next1==next_index then nothing special needs to be done */
          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
                                           to_next, n_left_to_next,
                                           bi0, bi1, next0, next1);
        }

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t *b0;
          u32 next0;
          u32 sw_if_index0;
          u32 feature_bitmap0;

          /* speculatively enqueue b0 to the current next frame */
          bi0 = from[0];
          to_next[0] = bi0;
          from += 1;
          to_next += 1;
          n_left_from -= 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);

          sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];

          /* process 1 packet */

          /* Remove ourself from the feature bitmap */
          feature_bitmap0 =
            vnet_buffer (b0)->l2.feature_bitmap & ~L2INPUT_FEAT_VTR;

          /* save for next feature graph nodes */
          vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap0;

          /* Determine the next node */
          next0 = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
                                                   feature_bitmap0);

          l2_output_config_t *config0;
          config0 = vec_elt_at_index (l2output_main.configs, sw_if_index0);

          if (PREDICT_FALSE (config0->out_vtr_flag))
            {
              if (config0->output_vtr.push_and_pop_bytes)
                {
                  /* perform the tag rewrite on one packet */
                  if (l2_vtr_process
                      (b0,
                       &(vec_elt_at_index
                         (l2output_main.configs, sw_if_index0)->input_vtr)))
                    {
                      /* Drop packet */
                      next0 = L2_INVTR_NEXT_DROP;
                      b0->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
              else if (config0->output_pbb_vtr.push_and_pop_bytes)
                {
                  if (l2_pbb_process (b0, &(config0->input_pbb_vtr)))
                    {
                      /* Drop packet */
                      next0 = L2_INVTR_NEXT_DROP;
                      b0->error = node->errors[L2_INVTR_ERROR_DROP];
                    }
                }
            }

          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
            {
              l2_invtr_trace_t *t =
                vlib_add_trace (vm, node, b0, sizeof (*t));
              ethernet_header_t *h0 = vlib_buffer_get_current (b0);
              t->sw_if_index = sw_if_index0;
              clib_memcpy (t->src, h0->src_address, 6);
              clib_memcpy (t->dst, h0->dst_address, 6);
              clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
            }

          /* verify speculative enqueue, maybe switch current next frame */
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next,
                                           bi0, next0);
        }

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}


/* *INDENT-OFF* */
VLIB_REGISTER_NODE (l2_invtr_node,static) = {
  .function = l2_invtr_node_fn,
  .name = "l2-input-vtr",
  .vector_size = sizeof (u32),
  .format_trace = format_l2_invtr_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(l2_invtr_error_strings),
  .error_strings = l2_invtr_error_strings,

  .n_next_nodes = L2_INVTR_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
       [L2_INVTR_NEXT_DROP]  = "error-drop",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (l2_invtr_node, l2_invtr_node_fn)
     clib_error_t *l2_invtr_init (vlib_main_t * vm)
{
  l2_invtr_main_t *mp = &l2_invtr_main;

  mp->vlib_main = vm;
  mp->vnet_main = vnet_get_main ();

  /* Initialize the feature next-node indexes */
  feat_bitmap_init_next_nodes (vm,
                               l2_invtr_node.index,
                               L2INPUT_N_FEAT,
                               l2input_get_feat_names (),
                               mp->feat_next_node_index);

  return 0;
}

VLIB_INIT_FUNCTION (l2_invtr_init);


/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */