src/vnet/ip/ip4_mtrie.c

   1 /*
   2  * Copyright (c) 2015 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /*
  16  * ip/ip4_fib.h: ip4 mtrie fib
  17  *
  18  * Copyright (c) 2012 Eliot Dresselhaus
  19  *
  20  * Permission is hereby granted, free of charge, to any person obtaining
  21  * a copy of this software and associated documentation files (the
  22  * "Software"), to deal in the Software without restriction, including
  23  * without limitation the rights to use, copy, modify, merge, publish,
  24  * distribute, sublicense, and/or sell copies of the Software, and to
  25  * permit persons to whom the Software is furnished to do so, subject to
  26  * the following conditions:
  27  *
  28  * The above copyright notice and this permission notice shall be
  29  * included in all copies or substantial portions of the Software.
  30  *
  31  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  32  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  33  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  34  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  35  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  36  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  37  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  38  */
  39
  40 #include <vnet/ip/ip.h>
  41 #include <vnet/ip/ip4_mtrie.h>
  42 #include <vnet/fib/ip4_fib.h>
  43
  44
  45 /**
  46  * Global pool of IPv4 8bit PLYs
  47  */
  48 ip4_fib_mtrie_8_ply_t *ip4_ply_pool;
  49
  50 always_inline u32
  51 ip4_fib_mtrie_leaf_is_non_empty (ip4_fib_mtrie_8_ply_t * p, u8 dst_byte)
  52 {
  53   /*
  54    * It's 'non-empty' if the length of the leaf stored is greater than the
  55    * length of a leaf in the covering ply. i.e. the leaf is more specific
  56    * than it's would be cover in the covering ply
  57    */
  58   if (p->dst_address_bits_of_leaves[dst_byte] > p->dst_address_bits_base)
  59     return (1);
  60   return (0);
  61 }
  62
  63 always_inline ip4_fib_mtrie_leaf_t
  64 ip4_fib_mtrie_leaf_set_adj_index (u32 adj_index)
  65 {
  66   ip4_fib_mtrie_leaf_t l;
  67   l = 1 + 2 * adj_index;
  68   ASSERT (ip4_fib_mtrie_leaf_get_adj_index (l) == adj_index);
  69   return l;
  70 }
  71
  72 always_inline u32
  73 ip4_fib_mtrie_leaf_is_next_ply (ip4_fib_mtrie_leaf_t n)
  74 {
  75   return (n & 1) == 0;
  76 }
  77
  78 always_inline u32
  79 ip4_fib_mtrie_leaf_get_next_ply_index (ip4_fib_mtrie_leaf_t n)
  80 {
  81   ASSERT (ip4_fib_mtrie_leaf_is_next_ply (n));
  82   return n >> 1;
  83 }
  84
  85 always_inline ip4_fib_mtrie_leaf_t
  86 ip4_fib_mtrie_leaf_set_next_ply_index (u32 i)
  87 {
  88   ip4_fib_mtrie_leaf_t l;
  89   l = 0 + 2 * i;
  90   ASSERT (ip4_fib_mtrie_leaf_get_next_ply_index (l) == i);
  91   return l;
  92 }
  93
  94 #ifndef __ALTIVEC__
  95 #define PLY_X4_SPLAT_INIT(init_x4, init) \
  96   init_x4 = u32x4_splat (init);
  97 #else
  98 #define PLY_X4_SPLAT_INIT(init_x4, init)                                \
  99 {                                                                       \
 100   u32x4_union_t y;                                                      \
 101   y.as_u32[0] = init;                                                   \
 102   y.as_u32[1] = init;                                                   \
 103   y.as_u32[2] = init;                                                   \
 104   y.as_u32[3] = init;                                                   \
 105   init_x4 = y.as_u32x4;                                                 \
 106 }
 107 #endif
 108
 109 #ifdef CLIB_HAVE_VEC128
 110 #define PLY_INIT_LEAVES(p)                                              \
 111 {                                                                       \
 112     u32x4 *l, init_x4;                                                  \
 113                                                                         \
 114     PLY_X4_SPLAT_INIT(init_x4, init);                                   \
 115     for (l = p->leaves_as_u32x4;                                        \
 116          l < p->leaves_as_u32x4 + ARRAY_LEN (p->leaves_as_u32x4);       \
 117          l += 4)                                                        \
 118       {                                                                 \
 119         l[0] = init_x4;                                                 \
 120         l[1] = init_x4;                                                 \
 121         l[2] = init_x4;                                                 \
 122         l[3] = init_x4;                                                 \
 123       }                                                                 \
 124 }
 125 #else
 126 #define PLY_INIT_LEAVES(p)                                              \
 127 {                                                                       \
 128   u32 *l;                                                               \
 129                                                                         \
 130   for (l = p->leaves; l < p->leaves + ARRAY_LEN (p->leaves); l += 4)    \
 131     {                                                                   \
 132       l[0] = init;                                                      \
 133       l[1] = init;                                                      \
 134       l[2] = init;                                                      \
 135       l[3] = init;                                                      \
 136       }                                                                 \
 137 }
 138 #endif
 139
 140 #define PLY_INIT(p, init, prefix_len, ply_base_len)                     \
 141 {                                                                       \
 142   /*                                                                    \
 143    * A leaf is 'empty' if it represents a leaf from the covering PLY    \
 144    * i.e. if the prefix length of the leaf is less than or equal to     \
 145    * the prefix length of the PLY                                       \
 146    */                                                                   \
 147   p->n_non_empty_leafs = (prefix_len > ply_base_len ?                   \
 148                           ARRAY_LEN (p->leaves) : 0);                   \
 149   clib_memset (p->dst_address_bits_of_leaves, prefix_len,                    \
 150           sizeof (p->dst_address_bits_of_leaves));                      \
 151   p->dst_address_bits_base = ply_base_len;                              \
 152                                                                         \
 153   /* Initialize leaves. */                                              \
 154   PLY_INIT_LEAVES(p);                                                   \
 155 }
 156
 157 static void
 158 ply_8_init (ip4_fib_mtrie_8_ply_t * p,
 159             ip4_fib_mtrie_leaf_t init, uword prefix_len, u32 ply_base_len)
 160 {
 161   PLY_INIT (p, init, prefix_len, ply_base_len);
 162 }
 163
 164 static void
 165 ply_16_init (ip4_fib_mtrie_16_ply_t * p,
 166              ip4_fib_mtrie_leaf_t init, uword prefix_len)
 167 {
 168   clib_memset (p->dst_address_bits_of_leaves, prefix_len,
 169                sizeof (p->dst_address_bits_of_leaves));
 170   PLY_INIT_LEAVES (p);
 171 }
 172
 173 static ip4_fib_mtrie_leaf_t
 174 ply_create (ip4_fib_mtrie_t * m,
 175             ip4_fib_mtrie_leaf_t init_leaf,
 176             u32 leaf_prefix_len, u32 ply_base_len)
 177 {
 178   ip4_fib_mtrie_8_ply_t *p;
 179   void *old_heap;
 180   /* Get cache aligned ply. */
 181
 182   old_heap = clib_mem_set_heap (ip4_main.mtrie_mheap);
 183   pool_get_aligned (ip4_ply_pool, p, CLIB_CACHE_LINE_BYTES);
 184   clib_mem_set_heap (old_heap);
 185
 186   ply_8_init (p, init_leaf, leaf_prefix_len, ply_base_len);
 187   return ip4_fib_mtrie_leaf_set_next_ply_index (p - ip4_ply_pool);
 188 }
 189
 190 always_inline ip4_fib_mtrie_8_ply_t *
 191 get_next_ply_for_leaf (ip4_fib_mtrie_t * m, ip4_fib_mtrie_leaf_t l)
 192 {
 193   uword n = ip4_fib_mtrie_leaf_get_next_ply_index (l);
 194
 195   return pool_elt_at_index (ip4_ply_pool, n);
 196 }
 197
 198 void
 199 ip4_mtrie_free (ip4_fib_mtrie_t * m)
 200 {
 201   /* the root ply is embedded so there is nothing to do,
 202    * the assumption being that the IP4 FIB table has emptied the trie
 203    * before deletion.
 204    */
 205 #if CLIB_DEBUG > 0
 206   int i;
 207   for (i = 0; i < ARRAY_LEN (m->root_ply.leaves); i++)
 208     {
 209       ASSERT (!ip4_fib_mtrie_leaf_is_next_ply (m->root_ply.leaves[i]));
 210     }
 211 #endif
 212 }
 213
 214 void
 215 ip4_mtrie_init (ip4_fib_mtrie_t * m)
 216 {
 217   ply_16_init (&m->root_ply, IP4_FIB_MTRIE_LEAF_EMPTY, 0);
 218 }
 219
 220 typedef struct
 221 {
 222   ip4_address_t dst_address;
 223   u32 dst_address_length;
 224   u32 adj_index;
 225   u32 cover_address_length;
 226   u32 cover_adj_index;
 227 } ip4_fib_mtrie_set_unset_leaf_args_t;
 228
 229 static void
 230 set_ply_with_more_specific_leaf (ip4_fib_mtrie_t * m,
 231                                  ip4_fib_mtrie_8_ply_t * ply,
 232                                  ip4_fib_mtrie_leaf_t new_leaf,
 233                                  uword new_leaf_dst_address_bits)
 234 {
 235   ip4_fib_mtrie_leaf_t old_leaf;
 236   uword i;
 237
 238   ASSERT (ip4_fib_mtrie_leaf_is_terminal (new_leaf));
 239
 240   for (i = 0; i < ARRAY_LEN (ply->leaves); i++)
 241     {
 242       old_leaf = ply->leaves[i];
 243
 244       /* Recurse into sub plies. */
 245       if (!ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 246         {
 247           ip4_fib_mtrie_8_ply_t *sub_ply =
 248             get_next_ply_for_leaf (m, old_leaf);
 249           set_ply_with_more_specific_leaf (m, sub_ply, new_leaf,
 250                                            new_leaf_dst_address_bits);
 251         }
 252
 253       /* Replace less specific terminal leaves with new leaf. */
 254       else if (new_leaf_dst_address_bits >=
 255                ply->dst_address_bits_of_leaves[i])
 256         {
 257           clib_atomic_store_rel_n (&ply->leaves[i], new_leaf);
 258           ply->dst_address_bits_of_leaves[i] = new_leaf_dst_address_bits;
 259           ply->n_non_empty_leafs += ip4_fib_mtrie_leaf_is_non_empty (ply, i);
 260         }
 261     }
 262 }
 263
 264 static void
 265 set_leaf (ip4_fib_mtrie_t * m,
 266           const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 267           u32 old_ply_index, u32 dst_address_byte_index)
 268 {
 269   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 270   i32 n_dst_bits_next_plies;
 271   u8 dst_byte;
 272   ip4_fib_mtrie_8_ply_t *old_ply;
 273
 274   old_ply = pool_elt_at_index (ip4_ply_pool, old_ply_index);
 275
 276   ASSERT (a->dst_address_length <= 32);
 277   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 278
 279   /* how many bits of the destination address are in the next PLY */
 280   n_dst_bits_next_plies =
 281     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 282
 283   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 284
 285   /* Number of bits next plies <= 0 => insert leaves this ply. */
 286   if (n_dst_bits_next_plies <= 0)
 287     {
 288       /* The mask length of the address to insert maps to this ply */
 289       uword old_leaf_is_terminal;
 290       u32 i, n_dst_bits_this_ply;
 291
 292       /* The number of bits, and hence slots/buckets, we will fill */
 293       n_dst_bits_this_ply = clib_min (8, -n_dst_bits_next_plies);
 294       ASSERT ((a->dst_address.as_u8[dst_address_byte_index] &
 295                pow2_mask (n_dst_bits_this_ply)) == 0);
 296
 297       /* Starting at the value of the byte at this section of the v4 address
 298        * fill the buckets/slots of the ply */
 299       for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 300         {
 301           ip4_fib_mtrie_8_ply_t *new_ply;
 302
 303           old_leaf = old_ply->leaves[i];
 304           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 305
 306           if (a->dst_address_length >= old_ply->dst_address_bits_of_leaves[i])
 307             {
 308               /* The new leaf is more or equally specific than the one currently
 309                * occupying the slot */
 310               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 311
 312               if (old_leaf_is_terminal)
 313                 {
 314                   /* The current leaf is terminal, we can replace it with
 315                    * the new one */
 316                   old_ply->n_non_empty_leafs -=
 317                     ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 318
 319                   old_ply->dst_address_bits_of_leaves[i] =
 320                     a->dst_address_length;
 321                   clib_atomic_store_rel_n (&old_ply->leaves[i], new_leaf);
 322
 323                   old_ply->n_non_empty_leafs +=
 324                     ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 325                   ASSERT (old_ply->n_non_empty_leafs <=
 326                           ARRAY_LEN (old_ply->leaves));
 327                 }
 328               else
 329                 {
 330                   /* Existing leaf points to another ply.  We need to place
 331                    * new_leaf into all more specific slots. */
 332                   new_ply = get_next_ply_for_leaf (m, old_leaf);
 333                   set_ply_with_more_specific_leaf (m, new_ply, new_leaf,
 334                                                    a->dst_address_length);
 335                 }
 336             }
 337           else if (!old_leaf_is_terminal)
 338             {
 339               /* The current leaf is less specific and not termial (i.e. a ply),
 340                * recurse on down the trie */
 341               new_ply = get_next_ply_for_leaf (m, old_leaf);
 342               set_leaf (m, a, new_ply - ip4_ply_pool,
 343                         dst_address_byte_index + 1);
 344             }
 345           /*
 346            * else
 347            *  the route we are adding is less specific than the leaf currently
 348            *  occupying this slot. leave it there
 349            */
 350         }
 351     }
 352   else
 353     {
 354       /* The address to insert requires us to move down at a lower level of
 355        * the trie - recurse on down */
 356       ip4_fib_mtrie_8_ply_t *new_ply;
 357       u8 ply_base_len;
 358
 359       ply_base_len = 8 * (dst_address_byte_index + 1);
 360
 361       old_leaf = old_ply->leaves[dst_byte];
 362
 363       if (ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 364         {
 365           /* There is a leaf occupying the slot. Replace it with a new ply */
 366           old_ply->n_non_empty_leafs -=
 367             ip4_fib_mtrie_leaf_is_non_empty (old_ply, dst_byte);
 368
 369           new_leaf =
 370             ply_create (m, old_leaf,
 371                         old_ply->dst_address_bits_of_leaves[dst_byte],
 372                         ply_base_len);
 373           new_ply = get_next_ply_for_leaf (m, new_leaf);
 374
 375           /* Refetch since ply_create may move pool. */
 376           old_ply = pool_elt_at_index (ip4_ply_pool, old_ply_index);
 377
 378           clib_atomic_store_rel_n (&old_ply->leaves[dst_byte], new_leaf);
 379           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 380
 381           old_ply->n_non_empty_leafs +=
 382             ip4_fib_mtrie_leaf_is_non_empty (old_ply, dst_byte);
 383           ASSERT (old_ply->n_non_empty_leafs >= 0);
 384         }
 385       else
 386         new_ply = get_next_ply_for_leaf (m, old_leaf);
 387
 388       set_leaf (m, a, new_ply - ip4_ply_pool, dst_address_byte_index + 1);
 389     }
 390 }
 391
 392 static void
 393 set_root_leaf (ip4_fib_mtrie_t * m,
 394                const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 395 {
 396   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 397   ip4_fib_mtrie_16_ply_t *old_ply;
 398   i32 n_dst_bits_next_plies;
 399   u16 dst_byte;
 400
 401   old_ply = &m->root_ply;
 402
 403   ASSERT (a->dst_address_length <= 32);
 404
 405   /* how many bits of the destination address are in the next PLY */
 406   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 407
 408   dst_byte = a->dst_address.as_u16[0];
 409
 410   /* Number of bits next plies <= 0 => insert leaves this ply. */
 411   if (n_dst_bits_next_plies <= 0)
 412     {
 413       /* The mask length of the address to insert maps to this ply */
 414       uword old_leaf_is_terminal;
 415       u32 i, n_dst_bits_this_ply;
 416
 417       /* The number of bits, and hence slots/buckets, we will fill */
 418       n_dst_bits_this_ply = 16 - a->dst_address_length;
 419       ASSERT ((clib_host_to_net_u16 (a->dst_address.as_u16[0]) &
 420                pow2_mask (n_dst_bits_this_ply)) == 0);
 421
 422       /* Starting at the value of the byte at this section of the v4 address
 423        * fill the buckets/slots of the ply */
 424       for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 425         {
 426           ip4_fib_mtrie_8_ply_t *new_ply;
 427           u16 slot;
 428
 429           slot = clib_net_to_host_u16 (dst_byte);
 430           slot += i;
 431           slot = clib_host_to_net_u16 (slot);
 432
 433           old_leaf = old_ply->leaves[slot];
 434           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 435
 436           if (a->dst_address_length >=
 437               old_ply->dst_address_bits_of_leaves[slot])
 438             {
 439               /* The new leaf is more or equally specific than the one currently
 440                * occupying the slot */
 441               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 442
 443               if (old_leaf_is_terminal)
 444                 {
 445                   /* The current leaf is terminal, we can replace it with
 446                    * the new one */
 447                   old_ply->dst_address_bits_of_leaves[slot] =
 448                     a->dst_address_length;
 449                   clib_atomic_store_rel_n (&old_ply->leaves[slot], new_leaf);
 450                 }
 451               else
 452                 {
 453                   /* Existing leaf points to another ply.  We need to place
 454                    * new_leaf into all more specific slots. */
 455                   new_ply = get_next_ply_for_leaf (m, old_leaf);
 456                   set_ply_with_more_specific_leaf (m, new_ply, new_leaf,
 457                                                    a->dst_address_length);
 458                 }
 459             }
 460           else if (!old_leaf_is_terminal)
 461             {
 462               /* The current leaf is less specific and not termial (i.e. a ply),
 463                * recurse on down the trie */
 464               new_ply = get_next_ply_for_leaf (m, old_leaf);
 465               set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 466             }
 467           /*
 468            * else
 469            *  the route we are adding is less specific than the leaf currently
 470            *  occupying this slot. leave it there
 471            */
 472         }
 473     }
 474   else
 475     {
 476       /* The address to insert requires us to move down at a lower level of
 477        * the trie - recurse on down */
 478       ip4_fib_mtrie_8_ply_t *new_ply;
 479       u8 ply_base_len;
 480
 481       ply_base_len = 16;
 482
 483       old_leaf = old_ply->leaves[dst_byte];
 484
 485       if (ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 486         {
 487           /* There is a leaf occupying the slot. Replace it with a new ply */
 488           new_leaf =
 489             ply_create (m, old_leaf,
 490                         old_ply->dst_address_bits_of_leaves[dst_byte],
 491                         ply_base_len);
 492           new_ply = get_next_ply_for_leaf (m, new_leaf);
 493
 494           clib_atomic_store_rel_n (&old_ply->leaves[dst_byte], new_leaf);
 495           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 496         }
 497       else
 498         new_ply = get_next_ply_for_leaf (m, old_leaf);
 499
 500       set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 501     }
 502 }
 503
 504 static uword
 505 unset_leaf (ip4_fib_mtrie_t * m,
 506             const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 507             ip4_fib_mtrie_8_ply_t * old_ply, u32 dst_address_byte_index)
 508 {
 509   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 510   i32 n_dst_bits_next_plies;
 511   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 512   u8 dst_byte;
 513
 514   ASSERT (a->dst_address_length <= 32);
 515   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 516
 517   n_dst_bits_next_plies =
 518     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 519
 520   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 521   if (n_dst_bits_next_plies < 0)
 522     dst_byte &= ~pow2_mask (-n_dst_bits_next_plies);
 523
 524   n_dst_bits_this_ply =
 525     n_dst_bits_next_plies <= 0 ? -n_dst_bits_next_plies : 0;
 526   n_dst_bits_this_ply = clib_min (8, n_dst_bits_this_ply);
 527
 528   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 529
 530   for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 531     {
 532       old_leaf = old_ply->leaves[i];
 533       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 534
 535       if (old_leaf == del_leaf
 536           || (!old_leaf_is_terminal
 537               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf),
 538                              dst_address_byte_index + 1)))
 539         {
 540           old_ply->n_non_empty_leafs -=
 541             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 542
 543           clib_atomic_store_rel_n (&old_ply->leaves[i],
 544                                    ip4_fib_mtrie_leaf_set_adj_index
 545                                    (a->cover_adj_index));
 546           old_ply->dst_address_bits_of_leaves[i] = a->cover_address_length;
 547
 548           old_ply->n_non_empty_leafs +=
 549             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 550
 551           ASSERT (old_ply->n_non_empty_leafs >= 0);
 552           if (old_ply->n_non_empty_leafs == 0 && dst_address_byte_index > 0)
 553             {
 554               pool_put (ip4_ply_pool, old_ply);
 555               /* Old ply was deleted. */
 556               return 1;
 557             }
 558 #if CLIB_DEBUG > 0
 559           else if (dst_address_byte_index)
 560             {
 561               int ii, count = 0;
 562               for (ii = 0; ii < ARRAY_LEN (old_ply->leaves); ii++)
 563                 {
 564                   count += ip4_fib_mtrie_leaf_is_non_empty (old_ply, ii);
 565                 }
 566               ASSERT (count);
 567             }
 568 #endif
 569         }
 570     }
 571
 572   /* Old ply was not deleted. */
 573   return 0;
 574 }
 575
 576 static void
 577 unset_root_leaf (ip4_fib_mtrie_t * m,
 578                  const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 579 {
 580   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 581   i32 n_dst_bits_next_plies;
 582   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 583   u16 dst_byte;
 584   ip4_fib_mtrie_16_ply_t *old_ply;
 585
 586   ASSERT (a->dst_address_length <= 32);
 587
 588   old_ply = &m->root_ply;
 589   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 590
 591   dst_byte = a->dst_address.as_u16[0];
 592
 593   n_dst_bits_this_ply = (n_dst_bits_next_plies <= 0 ?
 594                          (16 - a->dst_address_length) : 0);
 595
 596   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 597
 598   /* Starting at the value of the byte at this section of the v4 address
 599    * fill the buckets/slots of the ply */
 600   for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 601     {
 602       u16 slot;
 603
 604       slot = clib_net_to_host_u16 (dst_byte);
 605       slot += i;
 606       slot = clib_host_to_net_u16 (slot);
 607
 608       old_leaf = old_ply->leaves[slot];
 609       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 610
 611       if (old_leaf == del_leaf
 612           || (!old_leaf_is_terminal
 613               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf), 2)))
 614         {
 615           clib_atomic_store_rel_n (&old_ply->leaves[slot],
 616                                    ip4_fib_mtrie_leaf_set_adj_index
 617                                    (a->cover_adj_index));
 618           old_ply->dst_address_bits_of_leaves[slot] = a->cover_address_length;
 619         }
 620     }
 621 }
 622
 623 void
 624 ip4_fib_mtrie_route_add (ip4_fib_mtrie_t * m,
 625                          const ip4_address_t * dst_address,
 626                          u32 dst_address_length, u32 adj_index)
 627 {
 628   ip4_fib_mtrie_set_unset_leaf_args_t a;
 629   ip4_main_t *im = &ip4_main;
 630
 631   /* Honor dst_address_length. Fib masks are in network byte order */
 632   a.dst_address.as_u32 = (dst_address->as_u32 &
 633                           im->fib_masks[dst_address_length]);
 634   a.dst_address_length = dst_address_length;
 635   a.adj_index = adj_index;
 636
 637   set_root_leaf (m, &a);
 638 }
 639
 640 void
 641 ip4_fib_mtrie_route_del (ip4_fib_mtrie_t * m,
 642                          const ip4_address_t * dst_address,
 643                          u32 dst_address_length,
 644                          u32 adj_index,
 645                          u32 cover_address_length, u32 cover_adj_index)
 646 {
 647   ip4_fib_mtrie_set_unset_leaf_args_t a;
 648   ip4_main_t *im = &ip4_main;
 649
 650   /* Honor dst_address_length. Fib masks are in network byte order */
 651   a.dst_address.as_u32 = (dst_address->as_u32 &
 652                           im->fib_masks[dst_address_length]);
 653   a.dst_address_length = dst_address_length;
 654   a.adj_index = adj_index;
 655   a.cover_adj_index = cover_adj_index;
 656   a.cover_address_length = cover_address_length;
 657
 658   /* the top level ply is never removed */
 659   unset_root_leaf (m, &a);
 660 }
 661
 662 /* Returns number of bytes of memory used by mtrie. */
 663 static uword
 664 mtrie_ply_memory_usage (ip4_fib_mtrie_t * m, ip4_fib_mtrie_8_ply_t * p)
 665 {
 666   uword bytes, i;
 667
 668   bytes = sizeof (p[0]);
 669   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 670     {
 671       ip4_fib_mtrie_leaf_t l = p->leaves[i];
 672       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 673         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 674     }
 675
 676   return bytes;
 677 }
 678
 679 /* Returns number of bytes of memory used by mtrie. */
 680 uword
 681 ip4_fib_mtrie_memory_usage (ip4_fib_mtrie_t * m)
 682 {
 683   uword bytes, i;
 684
 685   bytes = sizeof (*m);
 686   for (i = 0; i < ARRAY_LEN (m->root_ply.leaves); i++)
 687     {
 688       ip4_fib_mtrie_leaf_t l = m->root_ply.leaves[i];
 689       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 690         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 691     }
 692
 693   return bytes;
 694 }
 695
 696 static u8 *
 697 format_ip4_fib_mtrie_leaf (u8 * s, va_list * va)
 698 {
 699   ip4_fib_mtrie_leaf_t l = va_arg (*va, ip4_fib_mtrie_leaf_t);
 700
 701   if (ip4_fib_mtrie_leaf_is_terminal (l))
 702     s = format (s, "lb-index %d", ip4_fib_mtrie_leaf_get_adj_index (l));
 703   else
 704     s = format (s, "next ply %d", ip4_fib_mtrie_leaf_get_next_ply_index (l));
 705   return s;
 706 }
 707
 708 #define FORMAT_PLY(s, _p, _a, _i, _base_address, _ply_max_len, _indent) \
 709 ({                                                                      \
 710   u32 a, ia_length;                                                     \
 711   ip4_address_t ia;                                                     \
 712   ip4_fib_mtrie_leaf_t _l = p->leaves[(_i)];                            \
 713                                                                         \
 714   a = (_base_address) + ((_a) << (32 - (_ply_max_len)));                \
 715   ia.as_u32 = clib_host_to_net_u32 (a);                                 \
 716   ia_length = (_p)->dst_address_bits_of_leaves[(_i)];                   \
 717   s = format (s, "\n%U%U %U",                                           \
 718               format_white_space, (_indent) + 4,                        \
 719               format_ip4_address_and_length, &ia, ia_length,            \
 720               format_ip4_fib_mtrie_leaf, _l);                           \
 721                                                                         \
 722   if (ip4_fib_mtrie_leaf_is_next_ply (_l))                              \
 723     s = format (s, "\n%U",                                              \
 724                 format_ip4_fib_mtrie_ply, m, a, (_indent) + 8,          \
 725                 ip4_fib_mtrie_leaf_get_next_ply_index (_l));            \
 726   s;                                                                    \
 727 })
 728
 729 static u8 *
 730 format_ip4_fib_mtrie_ply (u8 * s, va_list * va)
 731 {
 732   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 733   u32 base_address = va_arg (*va, u32);
 734   u32 indent = va_arg (*va, u32);
 735   u32 ply_index = va_arg (*va, u32);
 736   ip4_fib_mtrie_8_ply_t *p;
 737   int i;
 738
 739   p = pool_elt_at_index (ip4_ply_pool, ply_index);
 740   s = format (s, "%Uply index %d, %d non-empty leaves",
 741               format_white_space, indent, ply_index, p->n_non_empty_leafs);
 742
 743   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 744     {
 745       if (ip4_fib_mtrie_leaf_is_non_empty (p, i))
 746         {
 747           s = FORMAT_PLY (s, p, i, i, base_address,
 748                           p->dst_address_bits_base + 8, indent);
 749         }
 750     }
 751
 752   return s;
 753 }
 754
 755 u8 *
 756 format_ip4_fib_mtrie (u8 * s, va_list * va)
 757 {
 758   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 759   int verbose = va_arg (*va, int);
 760   ip4_fib_mtrie_16_ply_t *p;
 761   u32 base_address = 0;
 762   int i;
 763
 764   s = format (s, "%d plies, memory usage %U\n",
 765               pool_elts (ip4_ply_pool),
 766               format_memory_size, ip4_fib_mtrie_memory_usage (m));
 767   s = format (s, "root-ply");
 768   p = &m->root_ply;
 769
 770   if (verbose)
 771     {
 772       s = format (s, "root-ply");
 773       p = &m->root_ply;
 774
 775       for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 776         {
 777           u16 slot;
 778
 779           slot = clib_host_to_net_u16 (i);
 780
 781           if (p->dst_address_bits_of_leaves[slot] > 0)
 782             {
 783               s = FORMAT_PLY (s, p, i, slot, base_address, 16, 0);
 784             }
 785         }
 786     }
 787
 788   return s;
 789 }
 790
 791 /** Default heap size for the IPv4 mtries */
 792 #define IP4_FIB_DEFAULT_MTRIE_HEAP_SIZE (32<<20)
 793
 794 static clib_error_t *
 795 ip4_mtrie_module_init (vlib_main_t * vm)
 796 {
 797   CLIB_UNUSED (ip4_fib_mtrie_8_ply_t * p);
 798   ip4_main_t *im = &ip4_main;
 799   clib_error_t *error = NULL;
 800   uword *old_heap;
 801
 802   if (0 == im->mtrie_heap_size)
 803     im->mtrie_heap_size = IP4_FIB_DEFAULT_MTRIE_HEAP_SIZE;
 804   im->mtrie_mheap = create_mspace (im->mtrie_heap_size, 1 /* locked */ );
 805
 806   /* Burn one ply so index 0 is taken */
 807   old_heap = clib_mem_set_heap (ip4_main.mtrie_mheap);
 808   pool_get (ip4_ply_pool, p);
 809   clib_mem_set_heap (old_heap);
 810
 811   return (error);
 812 }
 813
 814 VLIB_INIT_FUNCTION (ip4_mtrie_module_init);
 815
 816 /*
 817  * fd.io coding-style-patch-verification: ON
 818  *
 819  * Local Variables:
 820  * eval: (c-set-style "gnu")
 821  * End:
 822  */