l2_rw.c

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/*
 * 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.
 */

#include <vlib/vlib.h>
#include <vnet/l2/feat_bitmap.h>
#include <vnet/l2/l2_rw.h>

l2_rw_main_t l2_rw_main;

vlib_node_registration_t l2_rw_node;

typedef struct {
  u32 sw_if_index;
  u32 classify_table_index;
  u32 rewrite_entry_index;
} l2_rw_trace_t;

static u8 *format_l2_rw_entry (u8 * s, va_list *args)
{
  l2_rw_entry_t *e = va_arg (*args, l2_rw_entry_t *);
  l2_rw_main_t *rw = &l2_rw_main;
  s = format (s, "%d -  mask:%U value:%U\n",
              e - rw->entries,
              format_hex_bytes, e->mask, e->rewrite_n_vectors * sizeof(u32x4),
              format_hex_bytes, e->value, e->rewrite_n_vectors * sizeof(u32x4));
  s = format (s, "      hits:%d skip_bytes:%d",
                e->hit_count, e->skip_n_vectors * sizeof(u32x4));
  return s;
}

static u8 *format_l2_rw_config (u8 * s, va_list *args)
{
  l2_rw_config_t *c = va_arg (*args, l2_rw_config_t *);
  return format(s, "table-index:%d miss-index:%d",
                c->table_index,
                c->miss_index);
}

/* packet trace format function */
static u8 *format_l2_rw_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_rw_trace_t * t = va_arg (*args, l2_rw_trace_t *);
  return format (s, "l2-rw: sw_if_index %d, table %d, entry %d",
              t->sw_if_index, t->classify_table_index,
              t->rewrite_entry_index);
}

always_inline l2_rw_config_t *l2_rw_get_config(u32 sw_if_index)
{
  l2_rw_main_t *rw = &l2_rw_main;
  if (PREDICT_FALSE(!clib_bitmap_get(rw->configs_bitmap, sw_if_index))) {
    vec_validate(rw->configs, sw_if_index);
    rw->configs[sw_if_index].table_index = ~0;
    rw->configs[sw_if_index].miss_index = ~0;
    rw->configs_bitmap = clib_bitmap_set(rw->configs_bitmap, sw_if_index, 1);
  }
  return &rw->configs[sw_if_index];
}

static_always_inline void l2_rw_rewrite(l2_rw_entry_t *rwe, u8 *h)
{
  if (U32X4_ALIGNED(h)) {
    u32x4 *d = ((u32x4 *) h) + rwe->skip_n_vectors;
    switch(rwe->rewrite_n_vectors) {
      case 5:
        d[4] = (d[4] & ~rwe->mask[4]) | rwe->value[4];
        /* FALLTHROUGH */
      case 4:
        d[3] = (d[3] & ~rwe->mask[3]) | rwe->value[3];
        /* FALLTHROUGH */
      case 3:
        d[2] = (d[2] & ~rwe->mask[2]) | rwe->value[2];
        /* FALLTHROUGH */
      case 2:
        d[1] = (d[1] & ~rwe->mask[1]) | rwe->value[1];
        /* FALLTHROUGH */
      case 1:
        d[0] = (d[0] & ~rwe->mask[0]) | rwe->value[0];
        break;
      default:
        abort();
    }
  } else {
    u64 *d = ((u64 *) h) + rwe->skip_n_vectors * 2;
    switch(rwe->rewrite_n_vectors) {
      case 5:
        d[8] = (d[8] & ~(((u64*)rwe->mask)[8])) | (((u64*)rwe->value)[8]);
        d[9] = (d[9] & ~(((u64*)rwe->mask)[9])) | (((u64*)rwe->value)[9]);
        /* FALLTHROUGH */
      case 4:
        d[6] = (d[6] & ~(((u64*)rwe->mask)[6])) | (((u64*)rwe->value)[6]);
        d[7] = (d[7] & ~(((u64*)rwe->mask)[7])) | (((u64*)rwe->value)[7]);
        /* FALLTHROUGH */
      case 3:
        d[4] = (d[4] & ~(((u64*)rwe->mask)[4])) | (((u64*)rwe->value)[4]);
        d[5] = (d[5] & ~(((u64*)rwe->mask)[5])) | (((u64*)rwe->value)[5]);
        /* FALLTHROUGH */
      case 2:
        d[2] = (d[2] & ~(((u64*)rwe->mask)[2])) | (((u64*)rwe->value)[2]);
        d[3] = (d[3] & ~(((u64*)rwe->mask)[3])) | (((u64*)rwe->value)[3]);
        /* FALLTHROUGH */
      case 1:
        d[0] = (d[0] & ~(((u64*)rwe->mask)[0])) | (((u64*)rwe->value)[0]);
        d[1] = (d[1] & ~(((u64*)rwe->mask)[1])) | (((u64*)rwe->value)[1]);
        break;
      default:
        abort();
    }
  }
}

static uword
l2_rw_node_fn(vlib_main_t * vm,
              vlib_node_runtime_t * node,
              vlib_frame_t * frame)
{
  l2_rw_main_t *rw = &l2_rw_main;
  u32 n_left_from, * from, * to_next, next_index;
  //vlib_node_t *n = vlib_get_node(vm, node->node_index);
  vnet_classify_main_t *vcm = &vnet_classify_main;
  f64 now = vlib_time_now(vlib_get_main());
  u32 prefetch_size = 0;

  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 >= 4 && n_left_to_next >= 2)
    {
      u32 bi0, next0, sw_if_index0, feature_bitmap0, rwe_index0;
      u32 bi1, next1, sw_if_index1, feature_bitmap1, rwe_index1;
      vlib_buffer_t *b0, *b1;
      ethernet_header_t *h0, *h1;
      l2_rw_config_t *config0, *config1;
      u64 hash0, hash1;
      vnet_classify_table_t *t0, *t1;
      vnet_classify_entry_t *e0, *e1;
      l2_rw_entry_t *rwe0, *rwe1;

      {
        vlib_buffer_t * p2, * p3;
        p2 = vlib_get_buffer (vm, from[2]);
        p3 = vlib_get_buffer (vm, from[3]);

        vlib_prefetch_buffer_header (p2, LOAD);
        vlib_prefetch_buffer_header (p3, LOAD);
        CLIB_PREFETCH (p2->data, prefetch_size, LOAD);
        CLIB_PREFETCH (p3->data, prefetch_size, LOAD);
      }

      bi0 = from[0];
      bi1 = from[1];
      to_next[0] = bi0;
      to_next[1] = bi1;
      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);
      h0 = vlib_buffer_get_current(b0);
      h1 = vlib_buffer_get_current(b1);

      sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
      sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
      config0 = l2_rw_get_config(sw_if_index0); //TODO: check sw_if_index0 value
      config1 = l2_rw_get_config(sw_if_index1); //TODO: check sw_if_index0 value
      t0 = pool_elt_at_index(vcm->tables, config0->table_index);
      t1 = pool_elt_at_index(vcm->tables, config1->table_index);
      prefetch_size = (t1->skip_n_vectors + t1->match_n_vectors)*sizeof(u32x4);

      hash0 = vnet_classify_hash_packet(t0, (u8 *)h0);
      hash1 = vnet_classify_hash_packet(t1, (u8 *)h1);
      e0 = vnet_classify_find_entry(t0, (u8 *) h0, hash0, now);
      e1 = vnet_classify_find_entry(t1, (u8 *) h1, hash1, now);

      while (!e0 && (t0->next_table_index != ~0)) {
          t0 = pool_elt_at_index(vcm->tables, t0->next_table_index);
          hash0 = vnet_classify_hash_packet(t0, (u8 *)h0);
          e0 = vnet_classify_find_entry(t0, (u8 *) h0, hash0, now);
      }

      while (!e1 && (t1->next_table_index != ~0)) {
        t1 = pool_elt_at_index(vcm->tables, t1->next_table_index);
        hash1 = vnet_classify_hash_packet(t1, (u8 *)h1);
        e1 = vnet_classify_find_entry(t1, (u8 *) h1, hash1, now);
      }

      rwe_index0 = e0?e0->opaque_index:config0->miss_index;
      rwe_index1 = e1?e1->opaque_index:config1->miss_index;

      if (rwe_index0 != ~0) {
        rwe0 = pool_elt_at_index(rw->entries, rwe_index0);
        l2_rw_rewrite(rwe0, (u8 *)h0);
      }
      if (rwe_index1 != ~0) {
        rwe1 = pool_elt_at_index(rw->entries, rwe_index1);
        l2_rw_rewrite(rwe1, (u8 *)h1);
      }

      if (PREDICT_FALSE((b0->flags & VLIB_BUFFER_IS_TRACED))) {
        l2_rw_trace_t *t =
            vlib_add_trace (vm, node, b0, sizeof (*t));
        t->sw_if_index = sw_if_index0;
        t->classify_table_index = config0->table_index;
        t->rewrite_entry_index = rwe_index0;
      }

      if (PREDICT_FALSE((b1->flags & VLIB_BUFFER_IS_TRACED))) {
        l2_rw_trace_t *t =
            vlib_add_trace (vm, node, b1, sizeof (*t));
        t->sw_if_index = sw_if_index1;
        t->classify_table_index = config1->table_index;
        t->rewrite_entry_index = rwe_index1;
      }

      // Update feature bitmap and get next feature index
      feature_bitmap0 = vnet_buffer(b0)->l2.feature_bitmap & ~L2INPUT_FEAT_RW;
      feature_bitmap1 = vnet_buffer(b1)->l2.feature_bitmap & ~L2INPUT_FEAT_RW;
      vnet_buffer(b0)->l2.feature_bitmap = feature_bitmap0;
      vnet_buffer(b1)->l2.feature_bitmap = feature_bitmap1;
      next0 = feat_bitmap_get_next_node_index(rw->feat_next_node_index,
                                              feature_bitmap0);
      next1 = feat_bitmap_get_next_node_index(rw->feat_next_node_index,
                                                    feature_bitmap1);

      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, next0, sw_if_index0, feature_bitmap0, rwe_index0;
      vlib_buffer_t *b0;
      ethernet_header_t *h0;
      l2_rw_config_t *config0;
      u64 hash0;
      vnet_classify_table_t *t0;
      vnet_classify_entry_t *e0;
      l2_rw_entry_t *rwe0;

      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);
      h0 = vlib_buffer_get_current(b0);

      sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
      config0 = l2_rw_get_config(sw_if_index0); //TODO: check sw_if_index0 value
      t0 = pool_elt_at_index(vcm->tables, config0->table_index);

      hash0 = vnet_classify_hash_packet(t0, (u8 *)h0);
      e0 = vnet_classify_find_entry(t0, (u8 *) h0, hash0, now);

      while (!e0 && (t0->next_table_index != ~0)) {
        t0 = pool_elt_at_index(vcm->tables, t0->next_table_index);
        hash0 = vnet_classify_hash_packet(t0, (u8 *)h0);
        e0 = vnet_classify_find_entry(t0, (u8 *) h0, hash0, now);
      }

      rwe_index0 = e0?e0->opaque_index:config0->miss_index;

      if (rwe_index0 != ~0) {
        rwe0 = pool_elt_at_index(rw->entries, rwe_index0);
        l2_rw_rewrite(rwe0, (u8 *)h0);
      }

      if (PREDICT_FALSE((b0->flags & VLIB_BUFFER_IS_TRACED))) {
        l2_rw_trace_t *t =
            vlib_add_trace (vm, node, b0, sizeof (*t));
        t->sw_if_index = sw_if_index0;
        t->classify_table_index = config0->table_index;
        t->rewrite_entry_index = rwe_index0;
      }

      // Update feature bitmap and get next feature index
      feature_bitmap0 = vnet_buffer(b0)->l2.feature_bitmap & ~L2INPUT_FEAT_RW;
      vnet_buffer(b0)->l2.feature_bitmap = feature_bitmap0;
      next0 = feat_bitmap_get_next_node_index(rw->feat_next_node_index,
                                              feature_bitmap0);

      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;
}

int l2_rw_mod_entry(u32 *index,
                    u8 *mask, u8 *value, u32 len,
                    u32 skip, u8 is_del)
{
  l2_rw_main_t *rw = &l2_rw_main;
  l2_rw_entry_t *e = 0;
  if (*index != ~0) {
    if (pool_is_free_index(rw->entries, *index)) {
      return -1;
    }
    e = pool_elt_at_index(rw->entries, *index);
  } else {
    pool_get(rw->entries, e);
    *index = e - rw->entries;
  }

  if (!e)
    return -1;

  if (is_del) {
    pool_put(rw->entries, e);
    return 0;
  }

  e->skip_n_vectors = skip / sizeof(u32x4);
  skip -= e->skip_n_vectors * sizeof(u32x4);
  e->rewrite_n_vectors = (skip + len - 1) / sizeof(u32x4) + 1;
  vec_alloc_aligned(e->mask, e->rewrite_n_vectors, sizeof(u32x4));
  memset(e->mask, 0, e->rewrite_n_vectors * sizeof(u32x4));
  vec_alloc_aligned(e->value, e->rewrite_n_vectors, sizeof(u32x4));
  memset(e->value, 0, e->rewrite_n_vectors * sizeof(u32x4));

  clib_memcpy(((u8 *)e->value) + skip, value, len);
  clib_memcpy(((u8 *)e->mask) + skip, mask, len);

  int i;
  for (i = 0; i < e->rewrite_n_vectors; i++) {
    e->value[i] &= e->mask[i];
  }

  return 0;
}

static clib_error_t *
l2_rw_entry_cli_fn (vlib_main_t * vm,
                            unformat_input_t * input,
                            vlib_cli_command_t * cmd)
{
  u32 index = ~0;
  u8 *mask = 0;
  u8 *value = 0;
  u32 skip = 0;
  u8 del = 0;

  while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
  {
    if (unformat (input, "index %d", &index))
      ;
    else if (unformat (input, "mask %U", unformat_hex_string, &mask))
      ;
    else if (unformat (input, "value %U", unformat_hex_string, &value))
      ;
    else if (unformat (input, "skip %d", &skip))
      ;
    else if (unformat (input, "del"))
      del = 1;
    else
      break;
  }

  if (!mask || !value)
    return clib_error_return(0, "Unspecified mask or value");

  if (vec_len(mask) != vec_len(value))
    return clib_error_return(0, "Mask and value lengths must be identical");

  int ret;
  if ((ret = l2_rw_mod_entry(&index, mask, value, vec_len(mask), skip, del)))
    return clib_error_return(0, "Could not add entry");

  return 0;
}

VLIB_CLI_COMMAND (l2_rw_entry_cli, static) = {
  .path = "l2 rewrite entry",
  .short_help =
  "l2 rewrite entry [index <index>] [mask <hex-mask>] [value <hex-value>] [skip <n_bytes>] [del]",
  .function = l2_rw_entry_cli_fn,
};

int l2_rw_interface_set_table(u32 sw_if_index,
                              u32 table_index,
                              u32 miss_index)
{
  l2_rw_config_t *c = l2_rw_get_config(sw_if_index);
  l2_rw_main_t *rw = &l2_rw_main;

  c->table_index = table_index;
  c->miss_index = miss_index;
  u32 feature_bitmap = (table_index == ~0)?0:L2INPUT_FEAT_RW;

  l2input_intf_bitmap_enable(sw_if_index, L2INPUT_FEAT_RW, feature_bitmap);

  if (c->table_index == ~0)
    clib_bitmap_set(rw->configs_bitmap, sw_if_index, 0);

  return 0;
}

static clib_error_t *
l2_rw_interface_cli_fn (vlib_main_t * vm,
                            unformat_input_t * input,
                            vlib_cli_command_t * cmd)
{
  vnet_main_t * vnm = vnet_get_main();
  u32 table_index = ~0;
  u32 sw_if_index = ~0;
  u32 miss_index = ~0;

  if (unformat_check_input(input) != UNFORMAT_END_OF_INPUT) {
    unformat (input, "%U", unformat_vnet_sw_interface,
                          vnm, &sw_if_index);
  }

  while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
  {
    if (unformat (input, "table %d", &table_index))
      ;
    else if (unformat (input, "miss-index %d", &miss_index))
      ;
    else
      break;
  }

  if (sw_if_index == ~0)
    return clib_error_return(0, "You must specify an interface 'iface <interface>'",
                                   format_unformat_error, input);
  int ret;
  if((ret = l2_rw_interface_set_table(sw_if_index, table_index, miss_index)))
    return clib_error_return(0, "l2_rw_interface_set_table returned %d", ret);

  return 0;
}

VLIB_CLI_COMMAND (l2_rw_interface_cli, static) = {
  .path = "set interface l2 rewrite",
  .short_help =
  "set interface l2 rewrite <interface> [table <table index>] [miss-index <entry-index>]",
  .function = l2_rw_interface_cli_fn,
};

static clib_error_t *
l2_rw_show_interfaces_cli_fn (vlib_main_t * vm,
                        unformat_input_t * input,
                        vlib_cli_command_t * cmd)
{
  l2_rw_main_t *rw = &l2_rw_main;
  if (clib_bitmap_count_set_bits(rw->configs_bitmap) == 0)
      vlib_cli_output (vm, "No interface is currently using l2 rewrite\n");

  uword i;
  clib_bitmap_foreach(i, rw->configs_bitmap, {
      vlib_cli_output (vm, "sw_if_index:%d %U\n", i, format_l2_rw_config, &rw->configs[i]);
  });
  return 0;
}

VLIB_CLI_COMMAND (l2_rw_show_interfaces_cli, static) = {
  .path = "show l2 rewrite interfaces",
  .short_help =
  "show l2 rewrite interfaces",
  .function = l2_rw_show_interfaces_cli_fn,
};

static clib_error_t *
l2_rw_show_entries_cli_fn (vlib_main_t * vm,
                        unformat_input_t * input,
                        vlib_cli_command_t * cmd)
{
  l2_rw_main_t *rw = &l2_rw_main;
  l2_rw_entry_t *e;
  if (pool_elts(rw->entries) == 0)
    vlib_cli_output (vm, "No entries\n");

  pool_foreach(e, rw->entries, {
    vlib_cli_output (vm, "%U\n", format_l2_rw_entry, e);
  });
  return 0;
}

VLIB_CLI_COMMAND (l2_rw_show_entries_cli, static) = {
  .path = "show l2 rewrite entries",
  .short_help =
  "show l2 rewrite entries",
  .function = l2_rw_show_entries_cli_fn,
};

int
l2_rw_enable_disable(u32 bridge_domain, u8 disable)
{
  u32 mask = L2INPUT_FEAT_RW;
  l2input_set_bridge_features(bridge_domain, mask,
                              disable ? 0: mask);
  return 0;
}

static clib_error_t *
l2_rw_set_cli_fn (vlib_main_t * vm,
                        unformat_input_t * input,
                        vlib_cli_command_t * cmd)
{
  u32 bridge_domain;
  u8 disable = 0;

  if (unformat_check_input(input) == UNFORMAT_END_OF_INPUT ||
      !unformat (input, "%d", &bridge_domain)) {
    return clib_error_return(0, "You must specify a bridge domain");
  }

  if (unformat_check_input(input) != UNFORMAT_END_OF_INPUT &&
      unformat (input, "disable")) {
    disable = 1;
  }

  if (l2_rw_enable_disable(bridge_domain, disable))
    return clib_error_return(0, "Could not enable or disable rewrite");

  return 0;
}

VLIB_CLI_COMMAND (l2_rw_set_cli, static) = {
  .path = "set bridge-domain rewrite",
  .short_help =
  "set bridge-domain rewrite <bridge-domain> [disable]",
  .function = l2_rw_set_cli_fn,
};

static
clib_error_t *l2_rw_init (vlib_main_t *vm)
{
  l2_rw_main_t *rw = &l2_rw_main;
  rw->configs = 0;
  rw->entries = 0;
  clib_bitmap_alloc(rw->configs_bitmap, 1);
  feat_bitmap_init_next_nodes(vm,
                              l2_rw_node.index,
                              L2INPUT_N_FEAT,
                              l2input_get_feat_names(),
                              rw->feat_next_node_index);
  return 0;
}
VLIB_INIT_FUNCTION (l2_rw_init);

enum {
  L2_RW_NEXT_DROP,
  L2_RW_N_NEXT,
};

#define foreach_l2_rw_error               \
_(UNKNOWN, "Unknown error")

typedef enum {
#define _(sym,str) L2_RW_ERROR_##sym,
  foreach_l2_rw_error
#undef _
  L2_RW_N_ERROR,
} l2_rw_error_t;

static char * l2_rw_error_strings[] = {
#define _(sym,string) string,
    foreach_l2_rw_error
#undef _
};

VLIB_REGISTER_NODE (l2_rw_node) = {
  .function = l2_rw_node_fn,
  .name = "l2-rw",
  .vector_size = sizeof (u32),
  .format_trace = format_l2_rw_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN(l2_rw_error_strings),
  .error_strings = l2_rw_error_strings,
  .runtime_data_bytes = 0,
  .n_next_nodes = L2_RW_N_NEXT,
  .next_nodes = { [L2_RW_NEXT_DROP]  = "error-drop"},
};