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   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   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
 180   /* Get cache aligned ply. */
 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 the 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           __sync_val_compare_and_swap (&ply->leaves[i], old_leaf, new_leaf);
 255           ASSERT (ply->leaves[i] == new_leaf);
 256           ply->dst_address_bits_of_leaves[i] = new_leaf_dst_address_bits;
 257           ply->n_non_empty_leafs += ip4_fib_mtrie_leaf_is_non_empty (ply, i);
 258         }
 259     }
 260 }
 261
 262 static void
 263 set_leaf (ip4_fib_mtrie_t * m,
 264           const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 265           u32 old_ply_index, u32 dst_address_byte_index)
 266 {
 267   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 268   i32 n_dst_bits_next_plies;
 269   u8 dst_byte;
 270   ip4_fib_mtrie_8_ply_t *old_ply;
 271
 272   old_ply = pool_elt_at_index (ip4_ply_pool, old_ply_index);
 273
 274   ASSERT (a->dst_address_length <= 32);
 275   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 276
 277   /* how many bits of the destination address are in the next PLY */
 278   n_dst_bits_next_plies =
 279     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 280
 281   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 282
 283   /* Number of bits next plies <= 0 => insert leaves this ply. */
 284   if (n_dst_bits_next_plies <= 0)
 285     {
 286       /* The mask length of the address to insert maps to this ply */
 287       uword old_leaf_is_terminal;
 288       u32 i, n_dst_bits_this_ply;
 289
 290       /* The number of bits, and hence slots/buckets, we will fill */
 291       n_dst_bits_this_ply = clib_min (8, -n_dst_bits_next_plies);
 292       ASSERT ((a->dst_address.as_u8[dst_address_byte_index] &
 293                pow2_mask (n_dst_bits_this_ply)) == 0);
 294
 295       /* Starting at the value of the byte at this section of the v4 address
 296        * fill the buckets/slots of the ply */
 297       for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 298         {
 299           ip4_fib_mtrie_8_ply_t *new_ply;
 300
 301           old_leaf = old_ply->leaves[i];
 302           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 303
 304           if (a->dst_address_length >= old_ply->dst_address_bits_of_leaves[i])
 305             {
 306               /* The new leaf is more or equally specific than the one currently
 307                * occupying the slot */
 308               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 309
 310               if (old_leaf_is_terminal)
 311                 {
 312                   /* The current leaf is terminal, we can replace it with
 313                    * the new one */
 314                   old_ply->n_non_empty_leafs -=
 315                     ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 316
 317                   old_ply->dst_address_bits_of_leaves[i] =
 318                     a->dst_address_length;
 319                   __sync_val_compare_and_swap (&old_ply->leaves[i], old_leaf,
 320                                                new_leaf);
 321                   ASSERT (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 = ply_create (m, old_leaf,
 370                                  clib_max (old_ply->dst_address_bits_of_leaves
 371                                            [dst_byte], ply_base_len),
 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           __sync_val_compare_and_swap (&old_ply->leaves[dst_byte], old_leaf,
 379                                        new_leaf);
 380           ASSERT (old_ply->leaves[dst_byte] == new_leaf);
 381           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 382
 383           old_ply->n_non_empty_leafs +=
 384             ip4_fib_mtrie_leaf_is_non_empty (old_ply, dst_byte);
 385           ASSERT (old_ply->n_non_empty_leafs >= 0);
 386         }
 387       else
 388         new_ply = get_next_ply_for_leaf (m, old_leaf);
 389
 390       set_leaf (m, a, new_ply - ip4_ply_pool, dst_address_byte_index + 1);
 391     }
 392 }
 393
 394 static void
 395 set_root_leaf (ip4_fib_mtrie_t * m,
 396                const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 397 {
 398   ip4_fib_mtrie_leaf_t old_leaf, new_leaf;
 399   ip4_fib_mtrie_16_ply_t *old_ply;
 400   i32 n_dst_bits_next_plies;
 401   u16 dst_byte;
 402
 403   old_ply = &m->root_ply;
 404
 405   ASSERT (a->dst_address_length <= 32);
 406
 407   /* how many bits of the destination address are in the next PLY */
 408   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 409
 410   dst_byte = a->dst_address.as_u16[0];
 411
 412   /* Number of bits next plies <= 0 => insert leaves this ply. */
 413   if (n_dst_bits_next_plies <= 0)
 414     {
 415       /* The mask length of the address to insert maps to this ply */
 416       uword old_leaf_is_terminal;
 417       u32 i, n_dst_bits_this_ply;
 418
 419       /* The number of bits, and hence slots/buckets, we will fill */
 420       n_dst_bits_this_ply = 16 - a->dst_address_length;
 421       ASSERT ((clib_host_to_net_u16 (a->dst_address.as_u16[0]) &
 422                pow2_mask (n_dst_bits_this_ply)) == 0);
 423
 424       /* Starting at the value of the byte at this section of the v4 address
 425        * fill the buckets/slots of the ply */
 426       for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 427         {
 428           ip4_fib_mtrie_8_ply_t *new_ply;
 429           u16 slot;
 430
 431           slot = clib_net_to_host_u16 (dst_byte);
 432           slot += i;
 433           slot = clib_host_to_net_u16 (slot);
 434
 435           old_leaf = old_ply->leaves[slot];
 436           old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 437
 438           if (a->dst_address_length >=
 439               old_ply->dst_address_bits_of_leaves[slot])
 440             {
 441               /* The new leaf is more or equally specific than the one currently
 442                * occupying the slot */
 443               new_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 444
 445               if (old_leaf_is_terminal)
 446                 {
 447                   /* The current leaf is terminal, we can replace it with
 448                    * the new one */
 449                   old_ply->dst_address_bits_of_leaves[slot] =
 450                     a->dst_address_length;
 451                   __sync_val_compare_and_swap (&old_ply->leaves[slot],
 452                                                old_leaf, new_leaf);
 453                   ASSERT (old_ply->leaves[slot] == new_leaf);
 454                 }
 455               else
 456                 {
 457                   /* Existing leaf points to another ply.  We need to place
 458                    * new_leaf into all more specific slots. */
 459                   new_ply = get_next_ply_for_leaf (m, old_leaf);
 460                   set_ply_with_more_specific_leaf (m, new_ply, new_leaf,
 461                                                    a->dst_address_length);
 462                 }
 463             }
 464           else if (!old_leaf_is_terminal)
 465             {
 466               /* The current leaf is less specific and not termial (i.e. a ply),
 467                * recurse on down the trie */
 468               new_ply = get_next_ply_for_leaf (m, old_leaf);
 469               set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 470             }
 471           /*
 472            * else
 473            *  the route we are adding is less specific than the leaf currently
 474            *  occupying this slot. leave it there
 475            */
 476         }
 477     }
 478   else
 479     {
 480       /* The address to insert requires us to move down at a lower level of
 481        * the trie - recurse on down */
 482       ip4_fib_mtrie_8_ply_t *new_ply;
 483       u8 ply_base_len;
 484
 485       ply_base_len = 16;
 486
 487       old_leaf = old_ply->leaves[dst_byte];
 488
 489       if (ip4_fib_mtrie_leaf_is_terminal (old_leaf))
 490         {
 491           /* There is a leaf occupying the slot. Replace it with a new ply */
 492           new_leaf = ply_create (m, old_leaf,
 493                                  clib_max (old_ply->dst_address_bits_of_leaves
 494                                            [dst_byte], ply_base_len),
 495                                  ply_base_len);
 496           new_ply = get_next_ply_for_leaf (m, new_leaf);
 497
 498           __sync_val_compare_and_swap (&old_ply->leaves[dst_byte], old_leaf,
 499                                        new_leaf);
 500           ASSERT (old_ply->leaves[dst_byte] == new_leaf);
 501           old_ply->dst_address_bits_of_leaves[dst_byte] = ply_base_len;
 502         }
 503       else
 504         new_ply = get_next_ply_for_leaf (m, old_leaf);
 505
 506       set_leaf (m, a, new_ply - ip4_ply_pool, 2);
 507     }
 508 }
 509
 510 static uword
 511 unset_leaf (ip4_fib_mtrie_t * m,
 512             const ip4_fib_mtrie_set_unset_leaf_args_t * a,
 513             ip4_fib_mtrie_8_ply_t * old_ply, u32 dst_address_byte_index)
 514 {
 515   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 516   i32 n_dst_bits_next_plies;
 517   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 518   u8 dst_byte;
 519
 520   ASSERT (a->dst_address_length <= 32);
 521   ASSERT (dst_address_byte_index < ARRAY_LEN (a->dst_address.as_u8));
 522
 523   n_dst_bits_next_plies =
 524     a->dst_address_length - BITS (u8) * (dst_address_byte_index + 1);
 525
 526   dst_byte = a->dst_address.as_u8[dst_address_byte_index];
 527   if (n_dst_bits_next_plies < 0)
 528     dst_byte &= ~pow2_mask (-n_dst_bits_next_plies);
 529
 530   n_dst_bits_this_ply =
 531     n_dst_bits_next_plies <= 0 ? -n_dst_bits_next_plies : 0;
 532   n_dst_bits_this_ply = clib_min (8, n_dst_bits_this_ply);
 533
 534   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 535
 536   for (i = dst_byte; i < dst_byte + (1 << n_dst_bits_this_ply); i++)
 537     {
 538       old_leaf = old_ply->leaves[i];
 539       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 540
 541       if (old_leaf == del_leaf
 542           || (!old_leaf_is_terminal
 543               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf),
 544                              dst_address_byte_index + 1)))
 545         {
 546           old_ply->n_non_empty_leafs -=
 547             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 548
 549           old_ply->leaves[i] =
 550             ip4_fib_mtrie_leaf_set_adj_index (a->cover_adj_index);
 551           old_ply->dst_address_bits_of_leaves[i] =
 552             clib_max (old_ply->dst_address_bits_base,
 553                       a->cover_address_length);
 554
 555           old_ply->n_non_empty_leafs +=
 556             ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);
 557
 558           ASSERT (old_ply->n_non_empty_leafs >= 0);
 559           if (old_ply->n_non_empty_leafs == 0 && dst_address_byte_index > 0)
 560             {
 561               pool_put (ip4_ply_pool, old_ply);
 562               /* Old ply was deleted. */
 563               return 1;
 564             }
 565 #if CLIB_DEBUG > 0
 566           else if (dst_address_byte_index)
 567             {
 568               int ii, count = 0;
 569               for (ii = 0; ii < ARRAY_LEN (old_ply->leaves); ii++)
 570                 {
 571                   count += ip4_fib_mtrie_leaf_is_non_empty (old_ply, ii);
 572                 }
 573               ASSERT (count);
 574             }
 575 #endif
 576         }
 577     }
 578
 579   /* Old ply was not deleted. */
 580   return 0;
 581 }
 582
 583 static void
 584 unset_root_leaf (ip4_fib_mtrie_t * m,
 585                  const ip4_fib_mtrie_set_unset_leaf_args_t * a)
 586 {
 587   ip4_fib_mtrie_leaf_t old_leaf, del_leaf;
 588   i32 n_dst_bits_next_plies;
 589   i32 i, n_dst_bits_this_ply, old_leaf_is_terminal;
 590   u16 dst_byte;
 591   ip4_fib_mtrie_16_ply_t *old_ply;
 592
 593   ASSERT (a->dst_address_length <= 32);
 594
 595   old_ply = &m->root_ply;
 596   n_dst_bits_next_plies = a->dst_address_length - BITS (u16);
 597
 598   dst_byte = a->dst_address.as_u16[0];
 599
 600   n_dst_bits_this_ply = (n_dst_bits_next_plies <= 0 ?
 601                          (16 - a->dst_address_length) : 0);
 602
 603   del_leaf = ip4_fib_mtrie_leaf_set_adj_index (a->adj_index);
 604
 605   /* Starting at the value of the byte at this section of the v4 address
 606    * fill the buckets/slots of the ply */
 607   for (i = 0; i < (1 << n_dst_bits_this_ply); i++)
 608     {
 609       u16 slot;
 610
 611       slot = clib_net_to_host_u16 (dst_byte);
 612       slot += i;
 613       slot = clib_host_to_net_u16 (slot);
 614
 615       old_leaf = old_ply->leaves[slot];
 616       old_leaf_is_terminal = ip4_fib_mtrie_leaf_is_terminal (old_leaf);
 617
 618       if (old_leaf == del_leaf
 619           || (!old_leaf_is_terminal
 620               && unset_leaf (m, a, get_next_ply_for_leaf (m, old_leaf), 2)))
 621         {
 622           old_ply->leaves[slot] =
 623             ip4_fib_mtrie_leaf_set_adj_index (a->cover_adj_index);
 624           old_ply->dst_address_bits_of_leaves[slot] = a->cover_address_length;
 625         }
 626     }
 627 }
 628
 629 void
 630 ip4_fib_mtrie_route_add (ip4_fib_mtrie_t * m,
 631                          const ip4_address_t * dst_address,
 632                          u32 dst_address_length, u32 adj_index)
 633 {
 634   ip4_fib_mtrie_set_unset_leaf_args_t a;
 635   ip4_main_t *im = &ip4_main;
 636
 637   /* Honor dst_address_length. Fib masks are in network byte order */
 638   a.dst_address.as_u32 = (dst_address->as_u32 &
 639                           im->fib_masks[dst_address_length]);
 640   a.dst_address_length = dst_address_length;
 641   a.adj_index = adj_index;
 642
 643   set_root_leaf (m, &a);
 644 }
 645
 646 void
 647 ip4_fib_mtrie_route_del (ip4_fib_mtrie_t * m,
 648                          const ip4_address_t * dst_address,
 649                          u32 dst_address_length,
 650                          u32 adj_index,
 651                          u32 cover_address_length, u32 cover_adj_index)
 652 {
 653   ip4_fib_mtrie_set_unset_leaf_args_t a;
 654   ip4_main_t *im = &ip4_main;
 655
 656   /* Honor dst_address_length. Fib masks are in network byte order */
 657   a.dst_address.as_u32 = (dst_address->as_u32 &
 658                           im->fib_masks[dst_address_length]);
 659   a.dst_address_length = dst_address_length;
 660   a.adj_index = adj_index;
 661   a.cover_adj_index = cover_adj_index;
 662   a.cover_address_length = cover_address_length;
 663
 664   /* the top level ply is never removed */
 665   unset_root_leaf (m, &a);
 666 }
 667
 668 /* Returns number of bytes of memory used by mtrie. */
 669 static uword
 670 mtrie_ply_memory_usage (ip4_fib_mtrie_t * m, ip4_fib_mtrie_8_ply_t * p)
 671 {
 672   uword bytes, i;
 673
 674   bytes = sizeof (p[0]);
 675   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 676     {
 677       ip4_fib_mtrie_leaf_t l = p->leaves[i];
 678       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 679         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 680     }
 681
 682   return bytes;
 683 }
 684
 685 /* Returns number of bytes of memory used by mtrie. */
 686 static uword
 687 mtrie_memory_usage (ip4_fib_mtrie_t * m)
 688 {
 689   uword bytes, i;
 690
 691   bytes = sizeof (*m);
 692   for (i = 0; i < ARRAY_LEN (m->root_ply.leaves); i++)
 693     {
 694       ip4_fib_mtrie_leaf_t l = m->root_ply.leaves[i];
 695       if (ip4_fib_mtrie_leaf_is_next_ply (l))
 696         bytes += mtrie_ply_memory_usage (m, get_next_ply_for_leaf (m, l));
 697     }
 698
 699   return bytes;
 700 }
 701
 702 static u8 *
 703 format_ip4_fib_mtrie_leaf (u8 * s, va_list * va)
 704 {
 705   ip4_fib_mtrie_leaf_t l = va_arg (*va, ip4_fib_mtrie_leaf_t);
 706
 707   if (ip4_fib_mtrie_leaf_is_terminal (l))
 708     s = format (s, "lb-index %d", ip4_fib_mtrie_leaf_get_adj_index (l));
 709   else
 710     s = format (s, "next ply %d", ip4_fib_mtrie_leaf_get_next_ply_index (l));
 711   return s;
 712 }
 713
 714 #define FORMAT_PLY(s, _p, _i, _base_address, _ply_max_len, _indent)     \
 715 ({                                                                      \
 716   u32 a, ia_length;                                                     \
 717   ip4_address_t ia;                                                     \
 718   ip4_fib_mtrie_leaf_t _l = p->leaves[(_i)];                            \
 719                                                                         \
 720   a = (_base_address) + ((_i) << (32 - (_ply_max_len)));                \
 721   ia.as_u32 = clib_host_to_net_u32 (a);                                 \
 722   ia_length = (_p)->dst_address_bits_of_leaves[(_i)];                   \
 723   s = format (s, "\n%U%20U %U",                                         \
 724               format_white_space, (_indent) + 2,                        \
 725               format_ip4_address_and_length, &ia, ia_length,            \
 726               format_ip4_fib_mtrie_leaf, _l);                           \
 727                                                                         \
 728   if (ip4_fib_mtrie_leaf_is_next_ply (_l))                              \
 729     s = format (s, "\n%U%U",                                            \
 730                 format_white_space, (_indent) + 2,                      \
 731                 format_ip4_fib_mtrie_ply, m, a,                         \
 732                 ip4_fib_mtrie_leaf_get_next_ply_index (_l));            \
 733   s;                                                                    \
 734 })
 735
 736 static u8 *
 737 format_ip4_fib_mtrie_ply (u8 * s, va_list * va)
 738 {
 739   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 740   u32 base_address = va_arg (*va, u32);
 741   u32 ply_index = va_arg (*va, u32);
 742   ip4_fib_mtrie_8_ply_t *p;
 743   u32 indent;
 744   int i;
 745
 746   p = pool_elt_at_index (ip4_ply_pool, ply_index);
 747   indent = format_get_indent (s);
 748   s = format (s, "ply index %d, %d non-empty leaves", ply_index,
 749               p->n_non_empty_leafs);
 750
 751   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 752     {
 753       if (ip4_fib_mtrie_leaf_is_non_empty (p, i))
 754         {
 755           FORMAT_PLY (s, p, i, base_address,
 756                       p->dst_address_bits_base + 8, indent);
 757         }
 758     }
 759
 760   return s;
 761 }
 762
 763 u8 *
 764 format_ip4_fib_mtrie (u8 * s, va_list * va)
 765 {
 766   ip4_fib_mtrie_t *m = va_arg (*va, ip4_fib_mtrie_t *);
 767   ip4_fib_mtrie_16_ply_t *p;
 768   u32 base_address = 0;
 769   int i;
 770
 771   s = format (s, "%d plies, memory usage %U\n",
 772               pool_elts (ip4_ply_pool),
 773               format_memory_size, mtrie_memory_usage (m));
 774   s = format (s, "root-ply");
 775   p = &m->root_ply;
 776
 777   for (i = 0; i < ARRAY_LEN (p->leaves); i++)
 778     {
 779       u16 slot;
 780
 781       slot = clib_host_to_net_u16 (i);
 782
 783       if (p->dst_address_bits_of_leaves[slot] > 0)
 784         {
 785           FORMAT_PLY (s, p, slot, base_address, 16, 2);
 786         }
 787     }
 788
 789   return s;
 790 }
 791
 792 static clib_error_t *
 793 ip4_mtrie_module_init (vlib_main_t * vm)
 794 {
 795   /* Burn one ply so index 0 is taken */
 796   CLIB_UNUSED (ip4_fib_mtrie_8_ply_t * p);
 797
 798   pool_get (ip4_ply_pool, p);
 799
 800   return (NULL);
 801 }
 802
 803 VLIB_INIT_FUNCTION (ip4_mtrie_module_init);
 804
 805 /*
 806  * fd.io coding-style-patch-verification: ON
 807  *
 808  * Local Variables:
 809  * eval: (c-set-style "gnu")
 810  * End:
 811  */