l2_fib.h

Go to the documentation of this file.

/*
 * l2_fib.h : layer 2 forwarding table (aka mac table)
 *
 * 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.
 */

#ifndef included_l2fib_h
#define included_l2fib_h

#include <vlib/vlib.h>
#include <vppinfra/bihash_8_8.h>

/*
 * The size of the hash table
 */
#define L2FIB_NUM_BUCKETS (64 * 1024)
#define L2FIB_MEMORY_SIZE (512<<20)

/* Ager scan interval is 1 minute for aging */
#define L2FIB_AGE_SCAN_INTERVAL         (60.0)

/* MAC event scan delay is 100 msec unless specified by MAC event client */
#define L2FIB_EVENT_SCAN_DELAY_DEFAULT  (0.1)

/* Max MACs in a event message is 100 unless specified by MAC event client */
#define L2FIB_EVENT_MAX_MACS_DEFAULT    (100)

/* MAC event learn limit is 1000 unless specified by MAC event client */
#define L2FIB_EVENT_LEARN_LIMIT_DEFAULT (1000)

typedef struct
{

  /* hash table */
  BVT (clib_bihash) mac_table;

  /* per swif vector of sequence number for interface based flush of MACs */
  u8 *swif_seq_num;

  /* last event or ager scan duration */
  f64 evt_scan_duration;
  f64 age_scan_duration;

  /* delay between event scans, default to 100 msec */
  f64 event_scan_delay;

  /* max macs in evet message, default to 100 entries */
  u32 max_macs_in_event;

  /* convenience variables */
  vlib_main_t *vlib_main;
  vnet_main_t *vnet_main;
} l2fib_main_t;

extern l2fib_main_t l2fib_main;

/*
 * The L2fib key is the mac address and bridge domain ID
 */
typedef struct
{
  union
  {
    struct
    {
      u16 bd_index;
      u8 mac[6];
    } fields;
    struct
    {
      u32 w0;
      u32 w1;
    } words;
    u64 raw;
  };
} l2fib_entry_key_t;

STATIC_ASSERT_SIZEOF (l2fib_entry_key_t, 8);


typedef struct
{
  union
  {
    struct
    {
      u8 swif;
      u8 bd;
    };
    u16 as_u16;
  };
} l2fib_seq_num_t;

/*
 * The l2fib entry results
 */
typedef struct
{
  union
  {
    struct
    {
      u32 sw_if_index;          /* output sw_if_index (L3 intf if bvi==1) */

      u8 static_mac:1;          /* static mac, no MAC move */
      u8 age_not:1;             /* not subject to age */
      u8 bvi:1;                 /* mac is for a bridged virtual interface */
      u8 filter:1;              /* drop packets to/from this mac */
      u8 lrn_evt:1;             /* MAC learned to be sent in L2 MAC event */
      u8 unused:3;

      u8 timestamp;             /* timestamp for aging */
      l2fib_seq_num_t sn;       /* bd/int seq num */
    } fields;
    u64 raw;
  };
} l2fib_entry_result_t;

STATIC_ASSERT_SIZEOF (l2fib_entry_result_t, 8);

/**
 * Compute the hash for the given key and return
 * the corresponding bucket index
 */
always_inline u32
l2fib_compute_hash_bucket (l2fib_entry_key_t * key)
{
  u32 result;
  u32 temp_a;
  u32 temp_b;

  result = 0xa5a5a5a5;          /* some seed */
  temp_a = key->words.w0;
  temp_b = key->words.w1;
  hash_mix32 (temp_a, temp_b, result);

  return result % L2FIB_NUM_BUCKETS;
}

/**
 * make address sanitizer skip this:
 * The 6-Bytes mac-address is cast into an 8-Bytes u64, with 2 additional Bytes.
 * l2fib_make_key() does read those two Bytes but does not use them.
 */
always_inline u64 __attribute__ ((no_sanitize_address))
l2fib_make_key (u8 * mac_address, u16 bd_index)
{
  u64 temp;

  /*
   * The mac address in memory is A:B:C:D:E:F
   * The bd id in register is H:L
   */
#if CLIB_ARCH_IS_LITTLE_ENDIAN
  /*
   * Create the in-register key as F:E:D:C:B:A:H:L
   * In memory the key is L:H:A:B:C:D:E:F
   */
  temp = *((u64 *) (mac_address)) << 16;
  temp = (temp & ~0xffff) | (u64) (bd_index);
#else
  /*
   * Create the in-register key as H:L:A:B:C:D:E:F
   * In memory the key is H:L:A:B:C:D:E:F
   */
  temp = *((u64 *) (mac_address)) >> 16;
  temp = temp | (((u64) bd_index) << 48);
#endif

  return temp;
}



/**
 * Lookup the entry for mac and bd_index in the mac table for 1 packet.
 * Cached_key and cached_result are used as a one-entry cache.
 * The function reads and updates them as needed.
 *
 * mac0 and bd_index0 are the keys. The entry is written to result0.
 * If the entry was not found, result0 is set to ~0.
 *
 * key0 and bucket0 return with the computed key and hash bucket,
 * convenient if the entry needs to be updated afterward.
 * If the cached_result was used, bucket0 is set to ~0.
 */

static_always_inline void
l2fib_lookup_1 (BVT (clib_bihash) * mac_table,
                l2fib_entry_key_t * cached_key,
                l2fib_entry_result_t * cached_result,
                u8 * mac0,
                u16 bd_index0,
                l2fib_entry_key_t * key0,
                u32 * bucket0, l2fib_entry_result_t * result0)
{
  /* set up key */
  key0->raw = l2fib_make_key (mac0, bd_index0);
  *bucket0 = ~0;

  if (key0->raw == cached_key->raw)
    {
      /* Hit in the one-entry cache */
      result0->raw = cached_result->raw;
    }
  else
    {
      /* Do a regular mac table lookup */
      BVT (clib_bihash_kv) kv;

      kv.key = key0->raw;
      kv.value = ~0ULL;
      BV (clib_bihash_search_inline) (mac_table, &kv);
      result0->raw = kv.value;

      /* Update one-entry cache */
      cached_key->raw = key0->raw;
      cached_result->raw = result0->raw;
    }
}


/**
 * Lookup the entry for mac and bd_index in the mac table for 2 packets.
 * The lookups for the two packets are interleaved.
 *
 * Cached_key and cached_result are used as a one-entry cache.
 * The function reads and updates them as needed.
 *
 * mac0 and bd_index0 are the keys. The entry is written to result0.
 * If the entry was not found, result0 is set to ~0. The same
 * holds for mac1/bd_index1/result1.
 */
static_always_inline void
l2fib_lookup_2 (BVT (clib_bihash) * mac_table,
                l2fib_entry_key_t * cached_key,
                l2fib_entry_result_t * cached_result,
                u8 * mac0,
                u8 * mac1,
                u16 bd_index0,
                u16 bd_index1,
                l2fib_entry_key_t * key0,
                l2fib_entry_key_t * key1,
                u32 * bucket0,
                u32 * bucket1,
                l2fib_entry_result_t * result0,
                l2fib_entry_result_t * result1)
{
  /* set up key */
  key0->raw = l2fib_make_key (mac0, bd_index0);
  key1->raw = l2fib_make_key (mac1, bd_index1);

  if ((key0->raw == cached_key->raw) && (key1->raw == cached_key->raw))
    {
      /* Both hit in the one-entry cache */
      result0->raw = cached_result->raw;
      result1->raw = cached_result->raw;
      *bucket0 = ~0;
      *bucket1 = ~0;

    }
  else
    {
      BVT (clib_bihash_kv) kv0, kv1;

      /*
       * Do a regular mac table lookup
       * Interleave lookups for packet 0 and packet 1
       */
      kv0.key = key0->raw;
      kv1.key = key1->raw;
      kv0.value = ~0ULL;
      kv1.value = ~0ULL;

      BV (clib_bihash_search_inline) (mac_table, &kv0);
      BV (clib_bihash_search_inline) (mac_table, &kv1);

      result0->raw = kv0.value;
      result1->raw = kv1.value;

      /* Update one-entry cache */
      cached_key->raw = key1->raw;
      cached_result->raw = result1->raw;
    }
}

static_always_inline void
l2fib_lookup_4 (BVT (clib_bihash) * mac_table,
                l2fib_entry_key_t * cached_key,
                l2fib_entry_result_t * cached_result,
                u8 * mac0,
                u8 * mac1,
                u8 * mac2,
                u8 * mac3,
                u16 bd_index0,
                u16 bd_index1,
                u16 bd_index2,
                u16 bd_index3,
                l2fib_entry_key_t * key0,
                l2fib_entry_key_t * key1,
                l2fib_entry_key_t * key2,
                l2fib_entry_key_t * key3,
                u32 * bucket0,
                u32 * bucket1,
                u32 * bucket2,
                u32 * bucket3,
                l2fib_entry_result_t * result0,
                l2fib_entry_result_t * result1,
                l2fib_entry_result_t * result2,
                l2fib_entry_result_t * result3)
{
  /* set up key */
  key0->raw = l2fib_make_key (mac0, bd_index0);
  key1->raw = l2fib_make_key (mac1, bd_index1);
  key2->raw = l2fib_make_key (mac2, bd_index2);
  key3->raw = l2fib_make_key (mac3, bd_index3);

  if ((key0->raw == cached_key->raw) && (key1->raw == cached_key->raw) &&
      (key2->raw == cached_key->raw) && (key3->raw == cached_key->raw))
    {
      /* Both hit in the one-entry cache */
      result0->raw = cached_result->raw;
      result1->raw = cached_result->raw;
      result2->raw = cached_result->raw;
      result3->raw = cached_result->raw;
      *bucket0 = ~0;
      *bucket1 = ~0;
      *bucket2 = ~0;
      *bucket3 = ~0;

    }
  else
    {
      BVT (clib_bihash_kv) kv0, kv1, kv2, kv3;

      /*
       * Do a regular mac table lookup
       * Interleave lookups for packet 0 and packet 1
       */
      kv0.key = key0->raw;
      kv1.key = key1->raw;
      kv2.key = key2->raw;
      kv3.key = key3->raw;
      kv0.value = ~0ULL;
      kv1.value = ~0ULL;
      kv2.value = ~0ULL;
      kv3.value = ~0ULL;

      BV (clib_bihash_search_inline) (mac_table, &kv0);
      BV (clib_bihash_search_inline) (mac_table, &kv1);
      BV (clib_bihash_search_inline) (mac_table, &kv2);
      BV (clib_bihash_search_inline) (mac_table, &kv3);

      result0->raw = kv0.value;
      result1->raw = kv1.value;
      result2->raw = kv2.value;
      result3->raw = kv3.value;

      /* Update one-entry cache */
      cached_key->raw = key1->raw;
      cached_result->raw = result1->raw;
    }
}

void l2fib_clear_table (void);

void
l2fib_add_entry (u8 * mac,
                 u32 bd_index,
                 u32 sw_if_index, u8 static_mac, u8 drop_mac, u8 bvi_mac);

static inline void
l2fib_add_fwd_entry (u8 * mac, u32 bd_index, u32 sw_if_index, u8 static_mac,
                     u8 bvi_mac)
{
  l2fib_add_entry (mac, bd_index, sw_if_index, static_mac, 0, bvi_mac);
}

static inline void
l2fib_add_filter_entry (u8 * mac, u32 bd_index)
{
  l2fib_add_entry (mac, bd_index, ~0, 1, 1, 0);
}

u32 l2fib_del_entry (u8 * mac, u32 bd_index);

void l2fib_start_ager_scan (vlib_main_t * vm);

void l2fib_flush_int_mac (vlib_main_t * vm, u32 sw_if_index);

void l2fib_flush_bd_mac (vlib_main_t * vm, u32 bd_index);

void l2fib_flush_all_mac (vlib_main_t * vm);

void
l2fib_table_dump (u32 bd_index, l2fib_entry_key_t ** l2fe_key,
                  l2fib_entry_result_t ** l2fe_res);

u8 *format_vnet_sw_if_index_name_with_NA (u8 * s, va_list * args);

static_always_inline u8 *
l2fib_swif_seq_num (u32 sw_if_index)
{
  l2fib_main_t *mp = &l2fib_main;
  return vec_elt_at_index (mp->swif_seq_num, sw_if_index);
}

static_always_inline u8 *
l2fib_valid_swif_seq_num (u32 sw_if_index)
{
  l2fib_main_t *mp = &l2fib_main;
  vec_validate (mp->swif_seq_num, sw_if_index);
  return l2fib_swif_seq_num (sw_if_index);
}

BVT (clib_bihash) * get_mac_table (void);

#endif

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