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   /* Get cache aligned ply. */
 180
 181   pool_get_aligned (ip4_ply_pool, p, CLIB_CACHE_LINE_BYTES);
 182
 183   ply_8_init (p, init_leaf, leaf_prefix_len, ply_base_len);
 184   return ip4_fib_mtrie_leaf_set_next_ply_index (p - ip4_ply_pool);
 185 }
 186
 187 always_inline ip4_fib_mtrie_8_ply_t *
 188 get_next_ply_for_leaf (ip4_fib_mtrie_t * m, ip4_fib_mtrie_leaf_t l)
 189 {
 190   uword n = ip4_fib_mtrie_leaf_get_next_ply_index (l);
 191
 192   return pool_elt_at_index (ip4_ply_pool, n);
 193 }
 194
 195 void
 196 ip4_mtrie_free (ip4_fib_mtrie_t * m)
 197 {
 198   /* the root ply is embedded so there is nothing to do,
 199    * the assumption being that the IP4 FIB table has emptied the trie
 200    * before deletion.
 201    */
 202 #if CLIB_DEBUG > 0
 203   int i;
 204   for (i = 0; i < ARRAY_LEN (m->root_ply.leaves); i++)
 205     {
 206       ASSERT (!ip4_fib_mtrie_leaf_is_next_ply (m->root_ply.leaves[i]));
 207     }
 208 #endif
 209 }
 210
 211 void
 212 ip4_mtrie_init (ip4_fib_mtrie_t * m)
 213 {
 214   ply_16_init (&m->root_ply, IP4_FIB_MTRIE_LEAF_EMPTY, 0);
 215 }
 216
 217 typedef struct
 218 {
 219   ip4_address_t dst_address;
 220   u32 dst_address_length;
 221   u32 adj_index;
 222   u32 cover_address_length;
 223   u32 cover_adj_index;
 224 } ip4_fib_mtrie_set_unset_leaf_args_t;
 225
 226 static void
 227 set_ply_with_more_specific_leaf (ip4_fib_mtrie_t * m,
 228                                  ip4_fib_mtrie_8_ply_t * ply,
 229                                  ip4_fib_mtrie_leaf_t new_leaf,
 230                                  uword new_leaf_dst_address_bits)
 231 {
 232   ip4_fib_mtrie_leaf_t old_leaf;
 233   uword i;
 234
 235   ASSERT (ip4_fib_mtrie_leaf_is_terminal (new_leaf));
 236
 237   for (i = 0; i < ARRAY_LEN (ply->leaves); i++)
 238     {
 239       old_leaf = ply->leaves[i];
 240
 241       /* Recurse into sub plies. */
 242       if (!ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 243         {
 244           ip4_fib_mtrie_8_ply_t *sub_ply =
 245             get_next_ply_for_leaf (m, old_leaf);
 246           set_ply_with_more_specific_leaf (m, sub_ply, new_leaf,
 247                                            new_leaf_dst_address_bits);
 248         }
 249
 250       /* Replace less specific terminal leaves with new leaf. */
 251       else if (new_leaf_dst_address_bits >=
 252                ply->dst_address_bits_of_leaves[i])
 253         {
 254           clib_atomic_store_rel_n (&ply->leaves[i], new_leaf);
 255           ply->dst_address_bits_of_leaves[i] = new_leaf_dst_address_bits;
 256           ply->n_non_empty_leafs += ip4_fib_mtrie_leaf_is_non_empty (ply, i);
 257         }
 258     }
 259 }
 260
 261 static void
 262 set_leaf (ip4_fib_mtrie_t * m,
 263           const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 264           u32 old_ply_index, u32 dst_address_byte_index)
 265 {
 266   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 267   i32 n_dst_bits_next_plies;
 268   u8 dst_byte;
 269   ip4_fib_mtrie_8_ply_t *old_ply;
 270
 271   old_ply = pool_elt_at_index (ip4_ply_pool, old_ply_index);
 272
 273   ASSERT (a->dst_address_length <= 32);
 274   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 275
 276   /* how many bits of the destination address are in the next PLY */
 277   n_dst_bits_next_plies =
 278     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 279
 280   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 281
 282   /* Number of bits next plies <= 0 => insert leaves this ply. */
 283   if (n_dst_bits_next_plies <= 0)
 284     {
 285       /* The mask length of the address to insert maps to this ply */
 286       uword old_leaf_is_terminal;
 287       u32 i, n_dst_bits_this_ply;
 288
 289       /* The number of bits, and hence slots/buckets, we will fill */
 290       n_dst_bits_this_ply = clib_min (8, -n_dst_bits_next_plies);
 291       ASSERT ((a->dst_address.as_u8[dst_address_byte_index] &
 292                pow2_mask (n_dst_bits_this_ply)) == 0);
 293
 294       /* Starting at the value of the byte at this section of the v4 address
 295        * fill the buckets/slots of the ply */
 296       for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 297         {
 298           ip4_fib_mtrie_8_ply_t *new_ply;
 299
 300           old_leaf = old_ply->leaves[i];
 301           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 302
 303           if (a->dst_address_length >= old_ply->dst_address_bits_of_leaves[i])
 304             {
 305               /* The new leaf is more or equally specific than the one currently
 306                * occupying the slot */
 307               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 308
 309               if (old_leaf_is_terminal)
 310                 {
 311                   /* The current leaf is terminal, we can replace it with
 312                    * the new one */
 313                   old_ply->n_non_empty_leafs -=
 314                     ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 315
 316                   old_ply->dst_address_bits_of_leaves[i] =
 317                     a->dst_address_length;
 318                   clib_atomic_store_rel_n (&old_ply->leaves[i], new_leaf);
 319
 320                   old_ply->n_non_empty_leafs +=
 321                     ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 322                   ASSERT (old_ply->n_non_empty_leafs <=
 323                           ARRAY_LEN (old_ply->leaves));
 324                 }
 325               else
 326                 {
 327                   /* Existing leaf points to another ply.  We need to place
 328                    * new_leaf into all more specific slots. */
 329                   new_ply = get_next_ply_for_leaf (m, old_leaf);
 330                   set_ply_with_more_specific_leaf (m, new_ply, new_leaf,
 331                                                    a->dst_address_length);
 332                 }
 333             }
 334           else if (!old_leaf_is_terminal)
 335             {
 336               /* The current leaf is less specific and not termial (i.e. a ply),
 337                * recurse on down the trie */
 338               new_ply = get_next_ply_for_leaf (m, old_leaf);
 339               set_leaf (m, a, new_ply - ip4_ply_pool,
 340                         dst_address_byte_index + 1);
 341             }
 342           /*
 343            * else
 344            *  the route we are adding is less specific than the leaf currently
 345            *  occupying this slot. leave it there
 346            */
 347         }
 348     }
 349   else
 350     {
 351       /* The address to insert requires us to move down at a lower level of
 352        * the trie - recurse on down */
 353       ip4_fib_mtrie_8_ply_t *new_ply;
 354       u8 ply_base_len;
 355
 356       ply_base_len = 8 * (dst_address_byte_index + 1);
 357
 358       old_leaf = old_ply->leaves[dst_byte];
 359
 360       if (ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 361         {
 362           /* There is a leaf occupying the slot. Replace it with a new ply */
 363           old_ply->n_non_empty_leafs -=
 364             ip4_fib_mtrie_leaf_is_non_empty (old_ply, dst_byte);
 365
 366           new_leaf =
 367             ply_create (m, old_leaf,
 368                         old_ply->dst_address_bits_of_leaves[dst_byte],
 369                         ply_base_len);
 370           new_ply = get_next_ply_for_leaf (m, new_leaf);
 371
 372           /* Refetch since ply_create may move pool. */
 373           old_ply = pool_elt_at_index (ip4_ply_pool, old_ply_index);
 374
 375           clib_atomic_store_rel_n (&old_ply->leaves[dst_byte], new_leaf);
 376           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 377
 378           old_ply->n_non_empty_leafs +=
 379             ip4_fib_mtrie_leaf_is_non_empty (old_ply, dst_byte);
 380           ASSERT (old_ply->n_non_empty_leafs >= 0);
 381         }
 382       else
 383         new_ply = get_next_ply_for_leaf (m, old_leaf);
 384
 385       set_leaf (m, a, new_ply - ip4_ply_pool, dst_address_byte_index + 1);
 386     }
 387 }
 388
 389 static void
 390 set_root_leaf (ip4_fib_mtrie_t * m,
 391                const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 392 {
 393   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 394   ip4_fib_mtrie_16_ply_t *old_ply;
 395   i32 n_dst_bits_next_plies;
 396   u16 dst_byte;
 397
 398   old_ply = &m->root_ply;
 399
 400   ASSERT (a->dst_address_length <= 32);
 401
 402   /* how many bits of the destination address are in the next PLY */
 403   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 404
 405   dst_byte = a->dst_address.as_u16[0];
 406
 407   /* Number of bits next plies <= 0 => insert leaves this ply. */
 408   if (n_dst_bits_next_plies <= 0)
 409     {
 410       /* The mask length of the address to insert maps to this ply */
 411       uword old_leaf_is_terminal;
 412       u32 i, n_dst_bits_this_ply;
 413
 414       /* The number of bits, and hence slots/buckets, we will fill */
 415       n_dst_bits_this_ply = 16 - a->dst_address_length;
 416       ASSERT ((clib_host_to_net_u16 (a->dst_address.as_u16[0]) &
 417                pow2_mask (n_dst_bits_this_ply)) == 0);
 418
 419       /* Starting at the value of the byte at this section of the v4 address
 420        * fill the buckets/slots of the ply */
 421       for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 422         {
 423           ip4_fib_mtrie_8_ply_t *new_ply;
 424           u16 slot;
 425
 426           slot = clib_net_to_host_u16 (dst_byte);
 427           slot += i;
 428           slot = clib_host_to_net_u16 (slot);
 429
 430           old_leaf = old_ply->leaves[slot];
 431           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 432
 433           if (a->dst_address_length >=
 434               old_ply->dst_address_bits_of_leaves[slot])
 435             {
 436               /* The new leaf is more or equally specific than the one currently
 437                * occupying the slot */
 438               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 439
 440               if (old_leaf_is_terminal)
 441                 {
 442                   /* The current leaf is terminal, we can replace it with
 443                    * the new one */
 444                   old_ply->dst_address_bits_of_leaves[slot] =
 445                     a->dst_address_length;
 446                   clib_atomic_store_rel_n (&old_ply->leaves[slot], new_leaf);
 447                 }
 448               else
 449                 {
 450                   /* Existing leaf points to another ply.  We need to place
 451                    * new_leaf into all more specific slots. */
 452                   new_ply = get_next_ply_for_leaf (m, old_leaf);
 453                   set_ply_with_more_specific_leaf (m, new_ply, new_leaf,
 454                                                    a->dst_address_length);
 455                 }
 456             }
 457           else if (!old_leaf_is_terminal)
 458             {
 459               /* The current leaf is less specific and not termial (i.e. a ply),
 460                * recurse on down the trie */
 461               new_ply = get_next_ply_for_leaf (m, old_leaf);
 462               set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 463             }
 464           /*
 465            * else
 466            *  the route we are adding is less specific than the leaf currently
 467            *  occupying this slot. leave it there
 468            */
 469         }
 470     }
 471   else
 472     {
 473       /* The address to insert requires us to move down at a lower level of
 474        * the trie - recurse on down */
 475       ip4_fib_mtrie_8_ply_t *new_ply;
 476       u8 ply_base_len;
 477
 478       ply_base_len = 16;
 479
 480       old_leaf = old_ply->leaves[dst_byte];
 481
 482       if (ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 483         {
 484           /* There is a leaf occupying the slot. Replace it with a new ply */
 485           new_leaf =
 486             ply_create (m, old_leaf,
 487                         old_ply->dst_address_bits_of_leaves[dst_byte],
 488                         ply_base_len);
 489           new_ply = get_next_ply_for_leaf (m, new_leaf);
 490
 491           clib_atomic_store_rel_n (&old_ply->leaves[dst_byte], new_leaf);
 492           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 493         }
 494       else
 495         new_ply = get_next_ply_for_leaf (m, old_leaf);
 496
 497       set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 498     }
 499 }
 500
 501 static uword
 502 unset_leaf (ip4_fib_mtrie_t * m,
 503             const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 504             ip4_fib_mtrie_8_ply_t * old_ply, u32 dst_address_byte_index)
 505 {
 506   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 507   i32 n_dst_bits_next_plies;
 508   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 509   u8 dst_byte;
 510
 511   ASSERT (a->dst_address_length <= 32);
 512   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 513
 514   n_dst_bits_next_plies =
 515     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 516
 517   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 518   if (n_dst_bits_next_plies < 0)
 519     dst_byte &= ~pow2_mask (-n_dst_bits_next_plies);
 520
 521   n_dst_bits_this_ply =
 522     n_dst_bits_next_plies <= 0 ? -n_dst_bits_next_plies : 0;
 523   n_dst_bits_this_ply = clib_min (8, n_dst_bits_this_ply);
 524
 525   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 526
 527   for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 528     {
 529       old_leaf = old_ply->leaves[i];
 530       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 531
 532       if (old_leaf == del_leaf
 533           || (!old_leaf_is_terminal
 534               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf),
 535                              dst_address_byte_index + 1)))
 536         {
 537           old_ply->n_non_empty_leafs -=
 538             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 539
 540           clib_atomic_store_rel_n (&old_ply->leaves[i],
 541                                    ip4_fib_mtrie_leaf_set_adj_index
 542                                    (a->cover_adj_index));
 543           old_ply->dst_address_bits_of_leaves[i] = a->cover_address_length;
 544
 545           old_ply->n_non_empty_leafs +=
 546             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 547
 548           ASSERT (old_ply->n_non_empty_leafs >= 0);
 549           if (old_ply->n_non_empty_leafs == 0 && dst_address_byte_index > 0)
 550             {
 551               pool_put (ip4_ply_pool, old_ply);
 552               /* Old ply was deleted. */
 553               return 1;
 554             }
 555 #if CLIB_DEBUG > 0
 556           else if (dst_address_byte_index)
 557             {
 558               int ii, count = 0;
 559               for (ii = 0; ii < ARRAY_LEN (old_ply->leaves); ii++)
 560                 {
 561                   count += ip4_fib_mtrie_leaf_is_non_empty (old_ply, ii);
 562                 }
 563               ASSERT (count);
 564             }
 565 #endif
 566         }
 567     }
 568
 569   /* Old ply was not deleted. */
 570   return 0;
 571 }
 572
 573 static void
 574 unset_root_leaf (ip4_fib_mtrie_t * m,
 575                  const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 576 {
 577   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 578   i32 n_dst_bits_next_plies;
 579   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 580   u16 dst_byte;
 581   ip4_fib_mtrie_16_ply_t *old_ply;
 582
 583   ASSERT (a->dst_address_length <= 32);
 584
 585   old_ply = &m->root_ply;
 586   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 587
 588   dst_byte = a->dst_address.as_u16[0];
 589
 590   n_dst_bits_this_ply = (n_dst_bits_next_plies <= 0 ?
 591                          (16 - a->dst_address_length) : 0);
 592
 593   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 594
 595   /* Starting at the value of the byte at this section of the v4 address
 596    * fill the buckets/slots of the ply */
 597   for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 598     {
 599       u16 slot;
 600
 601       slot = clib_net_to_host_u16 (dst_byte);
 602       slot += i;
 603       slot = clib_host_to_net_u16 (slot);
 604
 605       old_leaf = old_ply->leaves[slot];
 606       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 607
 608       if (old_leaf == del_leaf
 609           || (!old_leaf_is_terminal
 610               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf), 2)))
 611         {
 612           clib_atomic_store_rel_n (&old_ply->leaves[slot],
 613                                    ip4_fib_mtrie_leaf_set_adj_index
 614                                    (a->cover_adj_index));
 615           old_ply->dst_address_bits_of_leaves[slot] = a->cover_address_length;
 616         }
 617     }
 618 }
 619
 620 void
 621 ip4_fib_mtrie_route_add (ip4_fib_mtrie_t * m,
 622                          const ip4_address_t * dst_address,
 623                          u32 dst_address_length, u32 adj_index)
 624 {
 625   ip4_fib_mtrie_set_unset_leaf_args_t a;
 626   ip4_main_t *im = &ip4_main;
 627
 628   /* Honor dst_address_length. Fib masks are in network byte order */
 629   a.dst_address.as_u32 = (dst_address->as_u32 &
 630                           im->fib_masks[dst_address_length]);
 631   a.dst_address_length = dst_address_length;
 632   a.adj_index = adj_index;
 633
 634   set_root_leaf (m, &a);
 635 }
 636
 637 void
 638 ip4_fib_mtrie_route_del (ip4_fib_mtrie_t * m,
 639                          const ip4_address_t * dst_address,
 640                          u32 dst_address_length,
 641                          u32 adj_index,
 642                          u32 cover_address_length, u32 cover_adj_index)
 643 {
 644   ip4_fib_mtrie_set_unset_leaf_args_t a;
 645   ip4_main_t *im = &ip4_main;
 646
 647   /* Honor dst_address_length. Fib masks are in network byte order */
 648   a.dst_address.as_u32 = (dst_address->as_u32 &
 649                           im->fib_masks[dst_address_length]);
 650   a.dst_address_length = dst_address_length;
 651   a.adj_index = adj_index;
 652   a.cover_adj_index = cover_adj_index;
 653   a.cover_address_length = cover_address_length;
 654
 655   /* the top level ply is never removed */
 656   unset_root_leaf (m, &a);
 657 }
 658
 659 /* Returns number of bytes of memory used by mtrie. */
 660 static uword
 661 mtrie_ply_memory_usage (ip4_fib_mtrie_t * m, ip4_fib_mtrie_8_ply_t * p)
 662 {
 663   uword bytes, i;
 664
 665   bytes = sizeof (p[0]);
 666   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 667     {
 668       ip4_fib_mtrie_leaf_t l = p->leaves[i];
 669       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 670         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 671     }
 672
 673   return bytes;
 674 }
 675
 676 /* Returns number of bytes of memory used by mtrie. */
 677 uword
 678 ip4_fib_mtrie_memory_usage (ip4_fib_mtrie_t * m)
 679 {
 680   uword bytes, i;
 681
 682   bytes = sizeof (*m);
 683   for (i = 0; i < ARRAY_LEN (m->root_ply.leaves); i++)
 684     {
 685       ip4_fib_mtrie_leaf_t l = m->root_ply.leaves[i];
 686       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 687         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 688     }
 689
 690   return bytes;
 691 }
 692
 693 static u8 *
 694 format_ip4_fib_mtrie_leaf (u8 * s, va_list * va)
 695 {
 696   ip4_fib_mtrie_leaf_t l = va_arg (*va, ip4_fib_mtrie_leaf_t);
 697
 698   if (ip4_fib_mtrie_leaf_is_terminal (l))
 699     s = format (s, "lb-index %d", ip4_fib_mtrie_leaf_get_adj_index (l));
 700   else
 701     s = format (s, "next ply %d", ip4_fib_mtrie_leaf_get_next_ply_index (l));
 702   return s;
 703 }
 704
 705 #define FORMAT_PLY(s, _p, _a, _i, _base_address, _ply_max_len, _indent) \
 706 ({                                                                      \
 707   u32 a, ia_length;                                                     \
 708   ip4_address_t ia;                                                     \
 709   ip4_fib_mtrie_leaf_t _l = p->leaves[(_i)];                            \
 710                                                                         \
 711   a = (_base_address) + ((_a) << (32 - (_ply_max_len)));                \
 712   ia.as_u32 = clib_host_to_net_u32 (a);                                 \
 713   ia_length = (_p)->dst_address_bits_of_leaves[(_i)];                   \
 714   s = format (s, "\n%U%U %U",                                           \
 715               format_white_space, (_indent) + 4,                        \
 716               format_ip4_address_and_length, &ia, ia_length,            \
 717               format_ip4_fib_mtrie_leaf, _l);                           \
 718                                                                         \
 719   if (ip4_fib_mtrie_leaf_is_next_ply (_l))                              \
 720     s = format (s, "\n%U",                                              \
 721                 format_ip4_fib_mtrie_ply, m, a, (_indent) + 8,          \
 722                 ip4_fib_mtrie_leaf_get_next_ply_index (_l));            \
 723   s;                                                                    \
 724 })
 725
 726 static u8 *
 727 format_ip4_fib_mtrie_ply (u8 * s, va_list * va)
 728 {
 729   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 730   u32 base_address = va_arg (*va, u32);
 731   u32 indent = va_arg (*va, u32);
 732   u32 ply_index = va_arg (*va, u32);
 733   ip4_fib_mtrie_8_ply_t *p;
 734   int i;
 735
 736   p = pool_elt_at_index (ip4_ply_pool, ply_index);
 737   s = format (s, "%Uply index %d, %d non-empty leaves",
 738               format_white_space, indent, ply_index, p->n_non_empty_leafs);
 739
 740   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 741     {
 742       if (ip4_fib_mtrie_leaf_is_non_empty (p, i))
 743         {
 744           s = FORMAT_PLY (s, p, i, i, base_address,
 745                           p->dst_address_bits_base + 8, indent);
 746         }
 747     }
 748
 749   return s;
 750 }
 751
 752 u8 *
 753 format_ip4_fib_mtrie (u8 * s, va_list * va)
 754 {
 755   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 756   int verbose = va_arg (*va, int);
 757   ip4_fib_mtrie_16_ply_t *p;
 758   u32 base_address = 0;
 759   int i;
 760
 761   s = format (s, "%d plies, memory usage %U\n",
 762               pool_elts (ip4_ply_pool),
 763               format_memory_size, ip4_fib_mtrie_memory_usage (m));
 764   s = format (s, "root-ply");
 765   p = &m->root_ply;
 766
 767   if (verbose)
 768     {
 769       s = format (s, "root-ply");
 770       p = &m->root_ply;
 771
 772       for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 773         {
 774           u16 slot;
 775
 776           slot = clib_host_to_net_u16 (i);
 777
 778           if (p->dst_address_bits_of_leaves[slot] > 0)
 779             {
 780               s = FORMAT_PLY (s, p, i, slot, base_address, 16, 0);
 781             }
 782         }
 783     }
 784
 785   return s;
 786 }
 787
 788 /** Default heap size for the IPv4 mtries */
 789 #define IP4_FIB_DEFAULT_MTRIE_HEAP_SIZE (32<<20)
 790 #ifndef MAP_HUGE_SHIFT
 791 #define MAP_HUGE_SHIFT 26
 792 #endif
 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   clib_error_t *error = NULL;
 799
 800   /* Burn one ply so index 0 is taken */
 801   pool_get (ip4_ply_pool, p);
 802
 803   return (error);
 804 }
 805
 806 VLIB_INIT_FUNCTION (ip4_mtrie_module_init);
 807
 808 /*
 809  * fd.io coding-style-patch-verification: ON
 810  *
 811  * Local Variables:
 812  * eval: (c-set-style "gnu")
 813  * End:
 814  */