aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/ip/ip4_mtrie.h
blob: ec417c9a9f7249adacee35b0dfee951a8ee1211f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * ip/ip4_fib.h: ip4 mtrie fib
 *
 * Copyright (c) 2012 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef included_ip_ip4_fib_h
#define included_ip_ip4_fib_h

#include <vppinfra/cache.h>
#include <vppinfra/vector.h>
#include <vnet/ip/lookup.h>
#include <vnet/ip/ip4_packet.h>	/* for ip4_address_t */

/* ip4 fib leafs: 4 ply 8-8-8-8 mtrie.
   1 + 2*adj_index for terminal leaves.
   0 + 2*next_ply_index for non-terminals, i.e. PLYs
   1 => empty (adjacency index of zero is special miss adjacency). */
typedef u32 ip4_mtrie_leaf_t;

#define IP4_MTRIE_LEAF_EMPTY (1 + 2 * 0)

/**
 * @brief the 16 way stride that is the top PLY of the mtrie
 * We do not maintain the count of 'real' leaves in this PLY, since
 * it is never removed. The FIB will destroy the mtrie and the ply once
 * the FIB is destroyed.
 */
#define PLY_16_SIZE (1<<16)
typedef struct ip4_mtrie_16_ply_t_
{
  /**
   * The leaves/slots/buckets to be filed with leafs
   */
  union
  {
    ip4_mtrie_leaf_t leaves[PLY_16_SIZE];

#ifdef CLIB_HAVE_VEC128
    u32x4 leaves_as_u32x4[PLY_16_SIZE / 4];
#endif
  };

  /**
   * Prefix length for terminal leaves.
   */
  u8 dst_address_bits_of_leaves[PLY_16_SIZE];
} ip4_mtrie_16_ply_t;

/**
 * @brief One ply of the 4 ply mtrie fib.
 */
typedef struct ip4_mtrie_8_ply_t_
{
  /**
   * The leaves/slots/buckets to be filed with leafs
   */
  union
  {
    ip4_mtrie_leaf_t leaves[256];

#ifdef CLIB_HAVE_VEC128
    u32x4 leaves_as_u32x4[256 / 4];
#endif
  };

  /**
   * Prefix length for leaves/ply.
   */
  u8 dst_address_bits_of_leaves[256];

  /**
   * Number of non-empty leafs (whether terminal or not).
   */
  i32 n_non_empty_leafs;

  /**
   * The length of the ply's covering prefix. Also a measure of its depth
   * If a leaf in a slot has a mask length longer than this then it is
   * 'non-empty'. Otherwise it is the value of the cover.
   */
  i32 dst_address_bits_base;

  /* Pad to cache line boundary. */
  u8 pad[CLIB_CACHE_LINE_BYTES - 2 * sizeof (i32)];
} ip4_mtrie_8_ply_t;

STATIC_ASSERT (0 == sizeof (ip4_mtrie_8_ply_t) % CLIB_CACHE_LINE_BYTES,
	       "IP4 Mtrie ply cache line");

/**
 * @brief The mutiway-TRIE with a 16-8-8 stride.
 * There is no data associated with the mtrie apart from the top PLY
 */
typedef struct
{
  /**
   * Embed the PLY with the mtrie struct. This means that the Data-plane
   * 'get me the mtrie' returns the first ply, and not an indirect 'pointer'
   * to it. therefore no cacheline misses in the data-path.
   */
  ip4_mtrie_16_ply_t root_ply;
} ip4_mtrie_16_t;

/**
 * @brief The mutiway-TRIE with a 8-8-8-8 stride.
 * There is no data associated with the mtrie apart from the top PLY
 */
typedef struct
{
  /* pool index of the root ply */
  u32 root_ply;
} ip4_mtrie_8_t;

/**
 * @brief Initialise an mtrie
 */
void ip4_mtrie_16_init (ip4_mtrie_16_t *m);
void ip4_mtrie_8_init (ip4_mtrie_8_t *m);

/**
 * @brief Free an mtrie, It must be empty when free'd
 */
void ip4_mtrie_16_free (ip4_mtrie_16_t *m);
void ip4_mtrie_8_free (ip4_mtrie_8_t *m);

/**
 * @brief Add a route/entry to the mtrie
 */
void ip4_mtrie_16_route_add (ip4_mtrie_16_t *m,
			     const ip4_address_t *dst_address,
			     u32 dst_address_length, u32 adj_index);
void ip4_mtrie_8_route_add (ip4_mtrie_8_t *m, const ip4_address_t *dst_address,
			    u32 dst_address_length, u32 adj_index);

/**
 * @brief remove a route/entry to the mtrie
 */
void ip4_mtrie_16_route_del (ip4_mtrie_16_t *m,
			     const ip4_address_t *dst_address,
			     u32 dst_address_length, u32 adj_index,
			     u32 cover_address_length, u32 cover_adj_index);
void ip4_mtrie_8_route_del (ip4_mtrie_8_t *m, const ip4_address_t *dst_address,
			    u32 dst_address_length, u32 adj_index,
			    u32 cover_address_length, u32 cover_adj_index);

/**
 * @brief return the memory used by the table
 */
uword ip4_mtrie_16_memory_usage (ip4_mtrie_16_t *m);
uword ip4_mtrie_8_memory_usage (ip4_mtrie_8_t *m);

/**
 * @brief Format/display the contents of the mtrie
 */
format_function_t format_ip4_mtrie_16;
format_function_t format_ip4_mtrie_8;

/**
 * @brief A global pool of 8bit stride plys
 */
extern ip4_mtrie_8_ply_t *ip4_ply_pool;

/**
 * Is the leaf terminal (i.e. an LB index) or non-terminal (i.e. a PLY index)
 */
always_inline u32
ip4_mtrie_leaf_is_terminal (ip4_mtrie_leaf_t n)
{
  return n & 1;
}

/**
 * From the stored slot value extract the LB index value
 */
always_inline u32
ip4_mtrie_leaf_get_adj_index (ip4_mtrie_leaf_t n)
{
  ASSERT (ip4_mtrie_leaf_is_terminal (n));
  return n >> 1;
}

/**
 * @brief Lookup step.  Processes 1 byte of 4 byte ip4 address.
 */
always_inline ip4_mtrie_leaf_t
ip4_mtrie_16_lookup_step (ip4_mtrie_leaf_t current_leaf,
			  const ip4_address_t *dst_address,
			  u32 dst_address_byte_index)
{
  ip4_mtrie_8_ply_t *ply;

  uword current_is_terminal = ip4_mtrie_leaf_is_terminal (current_leaf);

  if (!current_is_terminal)
    {
      ply = ip4_ply_pool + (current_leaf >> 1);
      return (ply->leaves[dst_address->as_u8[dst_address_byte_index]]);
    }

  return current_leaf;
}

/**
 * @brief Lookup step number 1.  Processes 2 bytes of 4 byte ip4 address.
 */
always_inline ip4_mtrie_leaf_t
ip4_mtrie_16_lookup_step_one (const ip4_mtrie_16_t *m,
			      const ip4_address_t *dst_address)
{
  ip4_mtrie_leaf_t next_leaf;

  next_leaf = m->root_ply.leaves[dst_address->as_u16[0]];

  return next_leaf;
}

always_inline ip4_mtrie_leaf_t
ip4_mtrie_8_lookup_step (ip4_mtrie_leaf_t current_leaf,
			 const ip4_address_t *dst_address,
			 u32 dst_address_byte_index)
{
  ip4_mtrie_8_ply_t *ply;

  uword current_is_terminal = ip4_mtrie_leaf_is_terminal (current_leaf);

  if (!current_is_terminal)
    {
      ply = ip4_ply_pool + (current_leaf >> 1);
      return (ply->leaves[dst_address->as_u8[dst_address_byte_index]]);
    }

  return current_leaf;
}

always_inline ip4_mtrie_leaf_t
ip4_mtrie_8_lookup_step_one (const ip4_mtrie_8_t *m,
			     const ip4_address_t *dst_address)
{
  ip4_mtrie_leaf_t next_leaf;
  ip4_mtrie_8_ply_t *ply;

  ply = pool_elt_at_index (ip4_ply_pool, m->root_ply);
  next_leaf = ply->leaves[dst_address->as_u8[0]];

  return next_leaf;
}

#endif /* included_ip_ip4_fib_h */

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